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* [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data
@ 2021-09-01 17:00 Omar Sandoval
  2021-09-01 17:00 ` [PATCH v11 01/14] fs: export rw_verify_area() Omar Sandoval
                   ` (23 more replies)
  0 siblings, 24 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:00 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

This series has three parts: new Btrfs ioctls for reading/writing
compressed data, support for sending compressed data via Btrfs send, and
btrfs-progs support for sending/receiving compressed data and writing it
with the new ioctl.

Patches 1 and 2 are VFS changes exporting a couple of helpers for checks
needed by reads and writes. Patches 3-7 are preparatory Btrfs changes
for compressed reads and writes. Patch 8 adds the compressed read ioctl
and patch 9 adds the compressed write ioctl.

The main use-case for this interface is Btrfs send/receive. Currently,
when sending data from one compressed filesystem to another, the sending
side decompresses the data and the receiving side recompresses it before
writing it out. This is wasteful and can be avoided if we can just send
and write compressed extents.

Patches 10-14 add the Btrfs send support. See the previous posting for
more details and benchmarks [1]. Patches 10-12 prepare some protocol
changes for send stream v2. Patch 13 implements compressed send. Patch
14 enables send stream v2 and compressed send in the send ioctl when
requested.

These patches are based on Dave Sterba's Btrfs misc-next branch [2],
which is in turn currently based on v5.14-rc7. Test cases are here [3].

Changes since v10 [4]:

Addressed Dave's and Nikolay's comments, mostly stylistic.

- Renamed __generic_write_checks() to generic_write_checks_count().
- Add missing count == 0 check to generic_write_checks_count().
- Used in_range() macro in btrfs_csum_one_bio().
- Renamed page_offsets variable to use_page_offsets in
  btrfs_csum_one_bio().
- Removed conditional on offset increment in btrfs_csum_one_bio().
- Fixed stale reference to RWF_ENCODED in comment.

1: https://lore.kernel.org/linux-btrfs/cover.1615922753.git.osandov@fb.com/
2: https://github.com/kdave/btrfs-devel/tree/misc-next
3: https://github.com/osandov/xfstests/tree/btrfs-encoded-io
4: https://lore.kernel.org/linux-btrfs/cover.1629234193.git.osandov@fb.com/

Omar Sandoval (14):
  fs: export rw_verify_area()
  fs: export variant of generic_write_checks without iov_iter
  btrfs: don't advance offset for compressed bios in
    btrfs_csum_one_bio()
  btrfs: add ram_bytes and offset to btrfs_ordered_extent
  btrfs: support different disk extent size for delalloc
  btrfs: optionally extend i_size in cow_file_range_inline()
  btrfs: add definitions + documentation for encoded I/O ioctls
  btrfs: add BTRFS_IOC_ENCODED_READ
  btrfs: add BTRFS_IOC_ENCODED_WRITE
  btrfs: add send stream v2 definitions
  btrfs: send: write larger chunks when using stream v2
  btrfs: send: allocate send buffer with alloc_page() and vmap() for v2
  btrfs: send: send compressed extents with encoded writes
  btrfs: send: enable support for stream v2 and compressed writes

 fs/btrfs/compression.c     |  12 +-
 fs/btrfs/compression.h     |   6 +-
 fs/btrfs/ctree.h           |  17 +-
 fs/btrfs/delalloc-space.c  |  18 +-
 fs/btrfs/file-item.c       |  32 +-
 fs/btrfs/file.c            |  68 ++-
 fs/btrfs/inode.c           | 911 +++++++++++++++++++++++++++++++++----
 fs/btrfs/ioctl.c           | 213 +++++++++
 fs/btrfs/ordered-data.c    | 124 ++---
 fs/btrfs/ordered-data.h    |  25 +-
 fs/btrfs/relocation.c      |   2 +-
 fs/btrfs/send.c            | 307 +++++++++++--
 fs/btrfs/send.h            |  32 +-
 fs/internal.h              |   5 -
 fs/read_write.c            |  34 +-
 include/linux/fs.h         |   2 +
 include/uapi/linux/btrfs.h | 149 +++++-
 17 files changed, 1686 insertions(+), 271 deletions(-)

The btrfs-progs patches were written by Boris Burkov with some updates
from me. Patches 1-4 are preparation. Patch 5 implements encoded writes.
Patch 6 implements the fallback to decompressing. Patches 7 and 8
implement the other commands. Patch 9 adds the new `btrfs send` options.
Patch 10 adds a test case.

Changes from v10:

- Fixed feature fallback to check for ENOTTY instead of EOPNOTSUPP.

Boris Burkov (10):
  btrfs-progs: receive: support v2 send stream larger tlv_len
  btrfs-progs: receive: dynamically allocate sctx->read_buf
  btrfs-progs: receive: support v2 send stream DATA tlv format
  btrfs-progs: receive: add send stream v2 cmds and attrs to send.h
  btrfs-progs: receive: process encoded_write commands
  btrfs-progs: receive: encoded_write fallback to explicit decode and
    write
  btrfs-progs: receive: process fallocate commands
  btrfs-progs: receive: process setflags ioctl commands
  btrfs-progs: send: stream v2 ioctl flags
  btrfs-progs: receive: add tests for basic encoded_write send/receive

 Documentation/btrfs-receive.asciidoc          |   4 +
 Documentation/btrfs-send.asciidoc             |  16 +-
 cmds/receive-dump.c                           |  31 +-
 cmds/receive.c                                | 347 +++++++++++++++++-
 cmds/send.c                                   |  54 ++-
 common/send-stream.c                          | 157 ++++++--
 common/send-stream.h                          |   7 +
 ioctl.h                                       | 149 +++++++-
 libbtrfsutil/btrfs.h                          |  17 +-
 send.h                                        |  19 +-
 .../049-receive-write-encoded/test.sh         | 114 ++++++
 11 files changed, 871 insertions(+), 44 deletions(-)
 create mode 100755 tests/misc-tests/049-receive-write-encoded/test.sh

-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 01/14] fs: export rw_verify_area()
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
@ 2021-09-01 17:00 ` Omar Sandoval
  2021-11-18 19:19   ` Omar Sandoval
  2021-09-01 17:00 ` [PATCH v11 02/14] fs: export variant of generic_write_checks without iov_iter Omar Sandoval
                   ` (22 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:00 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

I'm adding Btrfs ioctls to read and write compressed data, and rather
than duplicating the checks in rw_verify_area(), let's just export it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/internal.h      | 5 -----
 fs/read_write.c    | 1 +
 include/linux/fs.h | 1 +
 3 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index 82e8eb32ff3d..f471894d87d4 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -165,11 +165,6 @@ extern char *simple_dname(struct dentry *, char *, int);
 extern void dput_to_list(struct dentry *, struct list_head *);
 extern void shrink_dentry_list(struct list_head *);
 
-/*
- * read_write.c
- */
-extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
-
 /*
  * pipe.c
  */
diff --git a/fs/read_write.c b/fs/read_write.c
index 9db7adf160d2..0029ff2b0ca8 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -400,6 +400,7 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
 	return security_file_permission(file,
 				read_write == READ ? MAY_READ : MAY_WRITE);
 }
+EXPORT_SYMBOL(rw_verify_area);
 
 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1751addcb36e..0de4d75339b9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3274,6 +3274,7 @@ extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
 		int whence, loff_t size);
 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
 extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
+extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
 extern int generic_file_open(struct inode * inode, struct file * filp);
 extern int nonseekable_open(struct inode * inode, struct file * filp);
 extern int stream_open(struct inode * inode, struct file * filp);
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 02/14] fs: export variant of generic_write_checks without iov_iter
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
  2021-09-01 17:00 ` [PATCH v11 01/14] fs: export rw_verify_area() Omar Sandoval
@ 2021-09-01 17:00 ` Omar Sandoval
  2021-10-14 12:03   ` Nikolay Borisov
  2021-09-01 17:00 ` [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio() Omar Sandoval
                   ` (21 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:00 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

Encoded I/O in Btrfs needs to check a write with a given logical size
without an iov_iter that matches that size (because the iov_iter we have
is for the compressed data). So, factor out the parts of
generic_write_check() that don't need an iov_iter into a new
generic_write_checks_count() function and export that.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/read_write.c    | 33 ++++++++++++++++++++-------------
 include/linux/fs.h |  1 +
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 0029ff2b0ca8..46b3dcff3b24 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1633,24 +1633,16 @@ int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count)
 	return 0;
 }
 
-/*
- * Performs necessary checks before doing a write
- *
- * Can adjust writing position or amount of bytes to write.
- * Returns appropriate error code that caller should return or
- * zero in case that write should be allowed.
- */
-ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
+/* Like generic_write_checks(), but takes size of write instead of iter. */
+int generic_write_checks_count(struct kiocb *iocb, loff_t *count)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
-	loff_t count;
-	int ret;
 
 	if (IS_SWAPFILE(inode))
 		return -ETXTBSY;
 
-	if (!iov_iter_count(from))
+	if (!*count)
 		return 0;
 
 	/* FIXME: this is for backwards compatibility with 2.4 */
@@ -1660,8 +1652,23 @@ ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
 	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
 		return -EINVAL;
 
-	count = iov_iter_count(from);
-	ret = generic_write_check_limits(file, iocb->ki_pos, &count);
+	return generic_write_check_limits(iocb->ki_filp, iocb->ki_pos, count);
+}
+EXPORT_SYMBOL(generic_write_checks_count);
+
+/*
+ * Performs necessary checks before doing a write
+ *
+ * Can adjust writing position or amount of bytes to write.
+ * Returns appropriate error code that caller should return or
+ * zero in case that write should be allowed.
+ */
+ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
+{
+	loff_t count = iov_iter_count(from);
+	int ret;
+
+	ret = generic_write_checks_count(iocb, &count);
 	if (ret)
 		return ret;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0de4d75339b9..3a2ff5306236 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3227,6 +3227,7 @@ extern int sb_min_blocksize(struct super_block *, int);
 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
+extern int generic_write_checks_count(struct kiocb *iocb, loff_t *count);
 extern int generic_write_check_limits(struct file *file, loff_t pos,
 		loff_t *count);
 extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio()
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
  2021-09-01 17:00 ` [PATCH v11 01/14] fs: export rw_verify_area() Omar Sandoval
  2021-09-01 17:00 ` [PATCH v11 02/14] fs: export variant of generic_write_checks without iov_iter Omar Sandoval
@ 2021-09-01 17:00 ` Omar Sandoval
  2021-10-14 12:05   ` Nikolay Borisov
  2021-09-01 17:00 ` [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent Omar Sandoval
                   ` (20 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:00 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

btrfs_csum_one_bio() loops over each filesystem block in the bio while
keeping a cursor of its current logical position in the file in order to
look up the ordered extent to add the checksums to. However, this
doesn't make much sense for compressed extents, as a sector on disk does
not correspond to a sector of decompressed file data. It happens to work
because 1) the compressed bio always covers one ordered extent and 2)
the size of the bio is always less than the size of the ordered extent.
However, the second point will not always be true for encoded writes.

Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that
it can assume that the bio only covers one ordered extent. Since we're
already changing the signature, let's get rid of the contig parameter
and make it implied by the offset parameter, similar to the change we
recently made to btrfs_lookup_bio_sums(). Additionally, let's rename
nr_sectors to blockcount to make it clear that it's the number of
filesystem blocks, not the number of 512-byte sectors.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/compression.c |  5 +++--
 fs/btrfs/ctree.h       |  2 +-
 fs/btrfs/file-item.c   | 32 ++++++++++++++------------------
 fs/btrfs/inode.c       |  8 ++++----
 4 files changed, 22 insertions(+), 25 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 7869ad12bc6e..e645b3c2f09a 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -480,7 +480,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 			BUG_ON(ret); /* -ENOMEM */
 
 			if (!skip_sum) {
-				ret = btrfs_csum_one_bio(inode, bio, start, 1);
+				ret = btrfs_csum_one_bio(inode, bio, start,
+							 true);
 				BUG_ON(ret); /* -ENOMEM */
 			}
 
@@ -516,7 +517,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 	BUG_ON(ret); /* -ENOMEM */
 
 	if (!skip_sum) {
-		ret = btrfs_csum_one_bio(inode, bio, start, 1);
+		ret = btrfs_csum_one_bio(inode, bio, start, true);
 		BUG_ON(ret); /* -ENOMEM */
 	}
 
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 38870ae46cbb..8ea383cac13b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3115,7 +3115,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct btrfs_ordered_sum *sums);
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
-				u64 file_start, int contig);
+				u64 offset, bool one_ordered);
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
 			     struct list_head *list, int search_commit);
 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 2673c6ba7a4e..aa5fb66e6987 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -614,28 +614,28 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
  * btrfs_csum_one_bio - Calculates checksums of the data contained inside a bio
  * @inode:	 Owner of the data inside the bio
  * @bio:	 Contains the data to be checksummed
- * @file_start:  offset in file this bio begins to describe
- * @contig:	 Boolean. If true/1 means all bio vecs in this bio are
- *		 contiguous and they begin at @file_start in the file. False/0
- *		 means this bio can contain potentially discontiguous bio vecs
- *		 so the logical offset of each should be calculated separately.
+ * @offset:      If (u64)-1, @bio may contain discontiguous bio vecs, so the
+ *               file offsets are determined from the page offsets in the bio.
+ *               Otherwise, this is the starting file offset of the bio vecs in
+ *               @bio, which must be contiguous.
+ * @one_ordered: If true, @bio only refers to one ordered extent.
  */
 blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
-		       u64 file_start, int contig)
+				u64 offset, bool one_ordered)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 	struct btrfs_ordered_sum *sums;
 	struct btrfs_ordered_extent *ordered = NULL;
+	const bool use_page_offsets = (offset == (u64)-1);
 	char *data;
 	struct bvec_iter iter;
 	struct bio_vec bvec;
 	int index;
-	int nr_sectors;
+	int blockcount;
 	unsigned long total_bytes = 0;
 	unsigned long this_sum_bytes = 0;
 	int i;
-	u64 offset;
 	unsigned nofs_flag;
 
 	nofs_flag = memalloc_nofs_save();
@@ -649,18 +649,13 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 	sums->len = bio->bi_iter.bi_size;
 	INIT_LIST_HEAD(&sums->list);
 
-	if (contig)
-		offset = file_start;
-	else
-		offset = 0; /* shut up gcc */
-
 	sums->bytenr = bio->bi_iter.bi_sector << 9;
 	index = 0;
 
 	shash->tfm = fs_info->csum_shash;
 
 	bio_for_each_segment(bvec, bio, iter) {
-		if (!contig)
+		if (use_page_offsets)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
 
 		if (!ordered) {
@@ -668,13 +663,14 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
 			BUG_ON(!ordered); /* Logic error */
 		}
 
-		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
+		blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
 						 bvec.bv_len + fs_info->sectorsize
 						 - 1);
 
-		for (i = 0; i < nr_sectors; i++) {
-			if (offset >= ordered->file_offset + ordered->num_bytes ||
-			    offset < ordered->file_offset) {
+		for (i = 0; i < blockcount; i++) {
+			if (!one_ordered &&
+			    !in_range(offset, ordered->file_offset,
+				      ordered->num_bytes)) {
 				unsigned long bytes_left;
 
 				sums->len = this_sum_bytes;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0517f31a3bed..8063d05e4a20 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2286,7 +2286,7 @@ int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
 static blk_status_t btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
 					   u64 dio_file_offset)
 {
-	return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
+	return btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
 }
 
 /*
@@ -2538,7 +2538,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio,
 					  0, btrfs_submit_bio_start);
 		goto out;
 	} else if (!skip_sum) {
-		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0);
+		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, (u64)-1, false);
 		if (ret)
 			goto out;
 	}
@@ -8140,7 +8140,7 @@ static blk_status_t btrfs_submit_bio_start_direct_io(struct inode *inode,
 						     struct bio *bio,
 						     u64 dio_file_offset)
 {
-	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, 1);
+	return btrfs_csum_one_bio(BTRFS_I(inode), bio, dio_file_offset, false);
 }
 
 static void btrfs_end_dio_bio(struct bio *bio)
@@ -8199,7 +8199,7 @@ static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
 		 * If we aren't doing async submit, calculate the csum of the
 		 * bio now.
 		 */
-		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, 1);
+		ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, false);
 		if (ret)
 			goto err;
 	} else {
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (2 preceding siblings ...)
  2021-09-01 17:00 ` [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio() Omar Sandoval
@ 2021-09-01 17:00 ` Omar Sandoval
  2021-10-21 12:44   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 05/14] btrfs: support different disk extent size for delalloc Omar Sandoval
                   ` (19 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:00 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

Currently, we only create ordered extents when ram_bytes == num_bytes
and offset == 0. However, RWF_ENCODED writes may create extents which
only refer to a subset of the full unencoded extent, so we need to plumb
these fields through the ordered extent infrastructure and pass them
down to insert_reserved_file_extent().

Since we're changing the btrfs_add_ordered_extent* signature, let's get
rid of the trivial wrappers and add a kernel-doc.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/inode.c        |  56 +++++++++++---------
 fs/btrfs/ordered-data.c | 112 +++++++++++-----------------------------
 fs/btrfs/ordered-data.h |  22 ++++----
 3 files changed, 76 insertions(+), 114 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8063d05e4a20..a85c1050ae95 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -945,12 +945,12 @@ static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
 			goto out_free_reserve;
 		free_extent_map(em);
 
-		ret = btrfs_add_ordered_extent_compress(inode,
-						async_extent->start,
-						ins.objectid,
-						async_extent->ram_size,
-						ins.offset,
-						async_extent->compress_type);
+		ret = btrfs_add_ordered_extent(inode, async_extent->start,
+					       async_extent->ram_size,
+					       async_extent->ram_size,
+					       ins.objectid, ins.offset, 0,
+					       1 << BTRFS_ORDERED_COMPRESSED,
+					       async_extent->compress_type);
 		if (ret) {
 			btrfs_drop_extent_cache(inode, async_extent->start,
 						async_extent->start +
@@ -1180,9 +1180,9 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 		}
 		free_extent_map(em);
 
-		ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
-					       ram_size, cur_alloc_size,
-					       BTRFS_ORDERED_REGULAR);
+		ret = btrfs_add_ordered_extent(inode, start, ram_size, ram_size,
+					       ins.objectid, cur_alloc_size, 0,
+					       0, BTRFS_COMPRESS_NONE);
 		if (ret)
 			goto out_drop_extent_cache;
 
@@ -1843,10 +1843,11 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
 				goto error;
 			}
 			free_extent_map(em);
-			ret = btrfs_add_ordered_extent(inode, cur_offset,
-						       disk_bytenr, num_bytes,
-						       num_bytes,
-						       BTRFS_ORDERED_PREALLOC);
+			ret = btrfs_add_ordered_extent(inode,
+					cur_offset, num_bytes, num_bytes,
+					disk_bytenr, num_bytes, 0,
+					1 << BTRFS_ORDERED_PREALLOC,
+					BTRFS_COMPRESS_NONE);
 			if (ret) {
 				btrfs_drop_extent_cache(inode, cur_offset,
 							cur_offset + num_bytes - 1,
@@ -1855,9 +1856,11 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
 			}
 		} else {
 			ret = btrfs_add_ordered_extent(inode, cur_offset,
+						       num_bytes, num_bytes,
 						       disk_bytenr, num_bytes,
-						       num_bytes,
-						       BTRFS_ORDERED_NOCOW);
+						       0,
+						       1 << BTRFS_ORDERED_NOCOW,
+						       BTRFS_COMPRESS_NONE);
 			if (ret)
 				goto error;
 		}
@@ -2842,6 +2845,7 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_key ins;
 	u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi);
 	u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi);
+	u64 offset = btrfs_stack_file_extent_offset(stack_fi);
 	u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi);
 	u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi);
 	struct btrfs_drop_extents_args drop_args = { 0 };
@@ -2916,7 +2920,8 @@ static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
 		goto out;
 
 	ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode),
-					       file_pos, qgroup_reserved, &ins);
+					       file_pos - offset,
+					       qgroup_reserved, &ins);
 out:
 	btrfs_free_path(path);
 
@@ -2942,20 +2947,20 @@ static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
 					     struct btrfs_ordered_extent *oe)
 {
 	struct btrfs_file_extent_item stack_fi;
-	u64 logical_len;
 	bool update_inode_bytes;
+	u64 num_bytes = oe->num_bytes;
+	u64 ram_bytes = oe->ram_bytes;
 
 	memset(&stack_fi, 0, sizeof(stack_fi));
 	btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG);
 	btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr);
 	btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi,
 						   oe->disk_num_bytes);
+	btrfs_set_stack_file_extent_offset(&stack_fi, oe->offset);
 	if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags))
-		logical_len = oe->truncated_len;
-	else
-		logical_len = oe->num_bytes;
-	btrfs_set_stack_file_extent_num_bytes(&stack_fi, logical_len);
-	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, logical_len);
+		num_bytes = ram_bytes = oe->truncated_len;
+	btrfs_set_stack_file_extent_num_bytes(&stack_fi, num_bytes);
+	btrfs_set_stack_file_extent_ram_bytes(&stack_fi, ram_bytes);
 	btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type);
 	/* Encryption and other encoding is reserved and all 0 */
 
@@ -7395,8 +7400,11 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 		if (IS_ERR(em))
 			goto out;
 	}
-	ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len,
-					   block_len, type);
+	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,
+				       block_len, 0,
+				       (1 << type) |
+				       (1 << BTRFS_ORDERED_DIRECT),
+				       BTRFS_COMPRESS_NONE);
 	if (ret) {
 		if (em) {
 			free_extent_map(em);
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index edb65abf0393..550c34fa0e6d 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -143,16 +143,27 @@ static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 	return ret;
 }
 
-/*
- * Allocate and add a new ordered_extent into the per-inode tree.
+/**
+ * btrfs_add_ordered_extent - Add an ordered extent to the per-inode tree.
+ * @inode: inode that this extent is for.
+ * @file_offset: Logical offset in file where the extent starts.
+ * @num_bytes: Logical length of extent in file.
+ * @ram_bytes: Full length of unencoded data.
+ * @disk_bytenr: Offset of extent on disk.
+ * @disk_num_bytes: Size of extent on disk.
+ * @offset: Offset into unencoded data where file data starts.
+ * @flags: Flags specifying type of extent (1 << BTRFS_ORDERED_*).
+ * @compress_type: Compression algorithm used for data.
  *
- * The tree is given a single reference on the ordered extent that was
- * inserted.
+ * Most of these parameters correspond to &struct btrfs_file_extent_item. The
+ * tree is given a single reference on the ordered extent that was inserted.
+ *
+ * Return: 0 or -ENOMEM.
  */
-static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int type, int dio,
-				      int compress_type)
+int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
+			     u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
+			     u64 disk_num_bytes, u64 offset, int flags,
+			     int compress_type)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -161,7 +172,8 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	struct btrfs_ordered_extent *entry;
 	int ret;
 
-	if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) {
+	if (flags &
+	    ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 		/* For nocow write, we can release the qgroup rsv right now */
 		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 		if (ret < 0)
@@ -181,9 +193,11 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 		return -ENOMEM;
 
 	entry->file_offset = file_offset;
-	entry->disk_bytenr = disk_bytenr;
 	entry->num_bytes = num_bytes;
+	entry->ram_bytes = ram_bytes;
+	entry->disk_bytenr = disk_bytenr;
 	entry->disk_num_bytes = disk_num_bytes;
+	entry->offset = offset;
 	entry->bytes_left = num_bytes;
 	entry->inode = igrab(&inode->vfs_inode);
 	entry->compress_type = compress_type;
@@ -191,18 +205,12 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	entry->qgroup_rsv = ret;
 	entry->physical = (u64)-1;
 
-	ASSERT(type == BTRFS_ORDERED_REGULAR ||
-	       type == BTRFS_ORDERED_NOCOW ||
-	       type == BTRFS_ORDERED_PREALLOC ||
-	       type == BTRFS_ORDERED_COMPRESSED);
-	set_bit(type, &entry->flags);
+	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
+	entry->flags = flags;
 
 	percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 				 fs_info->delalloc_batch);
 
-	if (dio)
-		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
-
 	/* one ref for the tree */
 	refcount_set(&entry->refs, 1);
 	init_waitqueue_head(&entry->wait);
@@ -247,41 +255,6 @@ static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset
 	return 0;
 }
 
-int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
-			     int type)
-{
-	ASSERT(type == BTRFS_ORDERED_REGULAR ||
-	       type == BTRFS_ORDERED_NOCOW ||
-	       type == BTRFS_ORDERED_PREALLOC);
-	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
-					  num_bytes, disk_num_bytes, type, 0,
-					  BTRFS_COMPRESS_NONE);
-}
-
-int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
-				 u64 disk_bytenr, u64 num_bytes,
-				 u64 disk_num_bytes, int type)
-{
-	ASSERT(type == BTRFS_ORDERED_REGULAR ||
-	       type == BTRFS_ORDERED_NOCOW ||
-	       type == BTRFS_ORDERED_PREALLOC);
-	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
-					  num_bytes, disk_num_bytes, type, 1,
-					  BTRFS_COMPRESS_NONE);
-}
-
-int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int compress_type)
-{
-	ASSERT(compress_type != BTRFS_COMPRESS_NONE);
-	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
-					  num_bytes, disk_num_bytes,
-					  BTRFS_ORDERED_COMPRESSED, 0,
-					  compress_type);
-}
-
 /*
  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
  * when an ordered extent is finished.  If the list covers more than one
@@ -1051,35 +1024,12 @@ static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
 	struct inode *inode = ordered->inode;
 	u64 file_offset = ordered->file_offset + pos;
 	u64 disk_bytenr = ordered->disk_bytenr + pos;
-	u64 num_bytes = len;
-	u64 disk_num_bytes = len;
-	int type;
-	unsigned long flags_masked = ordered->flags & ~(1 << BTRFS_ORDERED_DIRECT);
-	int compress_type = ordered->compress_type;
-	unsigned long weight;
-	int ret;
+	unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
 
-	weight = hweight_long(flags_masked);
-	WARN_ON_ONCE(weight > 1);
-	if (!weight)
-		type = 0;
-	else
-		type = __ffs(flags_masked);
-
-	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) {
-		WARN_ON_ONCE(1);
-		ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode),
-				file_offset, disk_bytenr, num_bytes,
-				disk_num_bytes, compress_type);
-	} else if (test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
-		ret = btrfs_add_ordered_extent_dio(BTRFS_I(inode), file_offset,
-				disk_bytenr, num_bytes, disk_num_bytes, type);
-	} else {
-		ret = btrfs_add_ordered_extent(BTRFS_I(inode), file_offset,
-				disk_bytenr, num_bytes, disk_num_bytes, type);
-	}
-
-	return ret;
+	WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
+	return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
+					disk_bytenr, len, 0, flags,
+					ordered->compress_type);
 }
 
 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 4194e960ff61..0feb0c29839e 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -76,6 +76,13 @@ enum {
 	BTRFS_ORDERED_PENDING,
 };
 
+/* BTRFS_ORDERED_* flags that specify the type of the extent. */
+#define BTRFS_ORDERED_TYPE_FLAGS ((1UL << BTRFS_ORDERED_REGULAR) |	\
+				  (1UL << BTRFS_ORDERED_NOCOW) |	\
+				  (1UL << BTRFS_ORDERED_PREALLOC) |	\
+				  (1UL << BTRFS_ORDERED_COMPRESSED) |	\
+				  (1UL << BTRFS_ORDERED_DIRECT))
+
 struct btrfs_ordered_extent {
 	/* logical offset in the file */
 	u64 file_offset;
@@ -84,9 +91,11 @@ struct btrfs_ordered_extent {
 	 * These fields directly correspond to the same fields in
 	 * btrfs_file_extent_item.
 	 */
-	u64 disk_bytenr;
 	u64 num_bytes;
+	u64 ram_bytes;
+	u64 disk_bytenr;
 	u64 disk_num_bytes;
+	u64 offset;
 
 	/* number of bytes that still need writing */
 	u64 bytes_left;
@@ -179,14 +188,9 @@ bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 				    struct btrfs_ordered_extent **cached,
 				    u64 file_offset, u64 io_size);
 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
-			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
-			     int type);
-int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
-				 u64 disk_bytenr, u64 num_bytes,
-				 u64 disk_num_bytes, int type);
-int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
-				      u64 disk_bytenr, u64 num_bytes,
-				      u64 disk_num_bytes, int compress_type);
+			     u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
+			     u64 disk_num_bytes, u64 offset, int flags,
+			     int compress_type);
 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 			   struct btrfs_ordered_sum *sum);
 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 05/14] btrfs: support different disk extent size for delalloc
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (3 preceding siblings ...)
  2021-09-01 17:00 ` [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-09-01 17:01 ` [PATCH v11 06/14] btrfs: optionally extend i_size in cow_file_range_inline() Omar Sandoval
                   ` (18 subsequent siblings)
  23 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

Currently, we always reserve the same extent size in the file and extent
size on disk for delalloc because the former is the worst case for the
latter. For RWF_ENCODED writes, we know the exact size of the extent on
disk, which may be less than or greater than (for bookends) the size in
the file. Add a disk_num_bytes parameter to
btrfs_delalloc_reserve_metadata() so that we can reserve the correct
amount of csum bytes. No functional change.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/ctree.h          |  3 ++-
 fs/btrfs/delalloc-space.c | 18 ++++++++++--------
 fs/btrfs/file.c           |  3 ++-
 fs/btrfs/inode.c          |  2 +-
 fs/btrfs/relocation.c     |  2 +-
 5 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8ea383cac13b..b95ec5fb68d5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2802,7 +2802,8 @@ void btrfs_subvolume_release_metadata(struct btrfs_root *root,
 				      struct btrfs_block_rsv *rsv);
 void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes);
 
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
 				   u64 start, u64 end);
diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index 2059d1504149..143650004991 100644
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -267,11 +267,11 @@ static void btrfs_calculate_inode_block_rsv_size(struct btrfs_fs_info *fs_info,
 }
 
 static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
-				    u64 num_bytes, u64 *meta_reserve,
-				    u64 *qgroup_reserve)
+				    u64 num_bytes, u64 disk_num_bytes,
+				    u64 *meta_reserve, u64 *qgroup_reserve)
 {
 	u64 nr_extents = count_max_extents(num_bytes);
-	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, num_bytes);
+	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, disk_num_bytes);
 	u64 inode_update = btrfs_calc_metadata_size(fs_info, 1);
 
 	*meta_reserve = btrfs_calc_insert_metadata_size(fs_info,
@@ -285,7 +285,8 @@ static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
 	*qgroup_reserve = nr_extents * fs_info->nodesize;
 }
 
-int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
+int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				    u64 disk_num_bytes)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -315,6 +316,7 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	}
 
 	num_bytes = ALIGN(num_bytes, fs_info->sectorsize);
+	disk_num_bytes = ALIGN(disk_num_bytes, fs_info->sectorsize);
 
 	/*
 	 * We always want to do it this way, every other way is wrong and ends
@@ -326,8 +328,8 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	 * everything out and try again, which is bad.  This way we just
 	 * over-reserve slightly, and clean up the mess when we are done.
 	 */
-	calc_inode_reservations(fs_info, num_bytes, &meta_reserve,
-				&qgroup_reserve);
+	calc_inode_reservations(fs_info, num_bytes, disk_num_bytes,
+				&meta_reserve, &qgroup_reserve);
 	ret = btrfs_qgroup_reserve_meta_prealloc(root, qgroup_reserve, true);
 	if (ret)
 		return ret;
@@ -346,7 +348,7 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 	spin_lock(&inode->lock);
 	nr_extents = count_max_extents(num_bytes);
 	btrfs_mod_outstanding_extents(inode, nr_extents);
-	inode->csum_bytes += num_bytes;
+	inode->csum_bytes += disk_num_bytes;
 	btrfs_calculate_inode_block_rsv_size(fs_info, inode);
 	spin_unlock(&inode->lock);
 
@@ -451,7 +453,7 @@ int btrfs_delalloc_reserve_space(struct btrfs_inode *inode,
 	ret = btrfs_check_data_free_space(inode, reserved, start, len);
 	if (ret < 0)
 		return ret;
-	ret = btrfs_delalloc_reserve_metadata(inode, len);
+	ret = btrfs_delalloc_reserve_metadata(inode, len, len);
 	if (ret < 0)
 		btrfs_free_reserved_data_space(inode, *reserved, start, len);
 	return ret;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 7ff577005d0f..6f9cb8baffd2 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1741,7 +1741,8 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
 					 fs_info->sectorsize);
 		WARN_ON(reserve_bytes == 0);
 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-				reserve_bytes);
+						      reserve_bytes,
+						      reserve_bytes);
 		if (ret) {
 			if (!only_release_metadata)
 				btrfs_free_reserved_data_space(BTRFS_I(inode),
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a85c1050ae95..6aad4b641d5c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5043,7 +5043,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
 			goto out;
 		}
 	}
-	ret = btrfs_delalloc_reserve_metadata(inode, blocksize);
+	ret = btrfs_delalloc_reserve_metadata(inode, blocksize, blocksize);
 	if (ret < 0) {
 		if (!only_release_metadata)
 			btrfs_free_reserved_data_space(inode, data_reserved,
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 63d2b22cf438..879fa0ea465c 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3017,7 +3017,7 @@ static int relocate_one_page(struct inode *inode, struct file_ra_state *ra,
 
 		/* Reserve metadata for this range */
 		ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
-						      clamped_len);
+						      clamped_len, clamped_len);
 		if (ret)
 			goto release_page;
 
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 06/14] btrfs: optionally extend i_size in cow_file_range_inline()
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (4 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 05/14] btrfs: support different disk extent size for delalloc Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-14 12:54   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls Omar Sandoval
                   ` (17 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

Currently, an inline extent is always created after i_size is extended
from btrfs_dirty_pages(). However, for encoded writes, we only want to
update i_size after we successfully created the inline extent. Add an
update_i_size parameter to cow_file_range_inline() and
insert_inline_extent() and pass in the size of the extent rather than
determining it from i_size. Since the start parameter is always passed
as 0, get rid of it and simplify the logic in these two functions. While
we're here, let's document the requirements for creating an inline
extent.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/inode.c | 100 +++++++++++++++++++++++------------------------
 1 file changed, 48 insertions(+), 52 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6aad4b641d5c..a87a34f56234 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -236,9 +236,10 @@ static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
 static int insert_inline_extent(struct btrfs_trans_handle *trans,
 				struct btrfs_path *path, bool extent_inserted,
 				struct btrfs_root *root, struct inode *inode,
-				u64 start, size_t size, size_t compressed_size,
+				size_t size, size_t compressed_size,
 				int compress_type,
-				struct page **compressed_pages)
+				struct page **compressed_pages,
+				bool update_i_size)
 {
 	struct extent_buffer *leaf;
 	struct page *page = NULL;
@@ -247,7 +248,7 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_file_extent_item *ei;
 	int ret;
 	size_t cur_size = size;
-	unsigned long offset;
+	u64 i_size;
 
 	ASSERT((compressed_size > 0 && compressed_pages) ||
 	       (compressed_size == 0 && !compressed_pages));
@@ -260,7 +261,7 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		size_t datasize;
 
 		key.objectid = btrfs_ino(BTRFS_I(inode));
-		key.offset = start;
+		key.offset = 0;
 		key.type = BTRFS_EXTENT_DATA_KEY;
 
 		datasize = btrfs_file_extent_calc_inline_size(cur_size);
@@ -297,12 +298,10 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 		btrfs_set_file_extent_compression(leaf, ei,
 						  compress_type);
 	} else {
-		page = find_get_page(inode->i_mapping,
-				     start >> PAGE_SHIFT);
+		page = find_get_page(inode->i_mapping, 0);
 		btrfs_set_file_extent_compression(leaf, ei, 0);
 		kaddr = kmap_atomic(page);
-		offset = offset_in_page(start);
-		write_extent_buffer(leaf, kaddr + offset, ptr, size);
+		write_extent_buffer(leaf, kaddr, ptr, size);
 		kunmap_atomic(kaddr);
 		put_page(page);
 	}
@@ -313,8 +312,8 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	 * We align size to sectorsize for inline extents just for simplicity
 	 * sake.
 	 */
-	size = ALIGN(size, root->fs_info->sectorsize);
-	ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, size);
+	ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0,
+					ALIGN(size, root->fs_info->sectorsize));
 	if (ret)
 		goto fail;
 
@@ -327,7 +326,13 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
 	 * before we unlock the pages.  Otherwise we
 	 * could end up racing with unlink.
 	 */
-	BTRFS_I(inode)->disk_i_size = inode->i_size;
+	i_size = i_size_read(inode);
+	if (update_i_size && size > i_size) {
+		i_size_write(inode, size);
+		i_size = size;
+	}
+	BTRFS_I(inode)->disk_i_size = i_size;
+
 fail:
 	return ret;
 }
@@ -338,35 +343,31 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
  * does the checks required to make sure the data is small enough
  * to fit as an inline extent.
  */
-static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
-					  u64 end, size_t compressed_size,
+static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
+					  size_t compressed_size,
 					  int compress_type,
-					  struct page **compressed_pages)
+					  struct page **compressed_pages,
+					  bool update_i_size)
 {
 	struct btrfs_drop_extents_args drop_args = { 0 };
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_trans_handle *trans;
-	u64 isize = i_size_read(&inode->vfs_inode);
-	u64 actual_end = min(end + 1, isize);
-	u64 inline_len = actual_end - start;
-	u64 aligned_end = ALIGN(end, fs_info->sectorsize);
-	u64 data_len = inline_len;
+	u64 data_len = compressed_size ? compressed_size : size;
 	int ret;
 	struct btrfs_path *path;
 
-	if (compressed_size)
-		data_len = compressed_size;
-
-	if (start > 0 ||
-	    actual_end > fs_info->sectorsize ||
+	/*
+	 * We can create an inline extent if it ends at or beyond the current
+	 * i_size, is no larger than a sector (decompressed), and the (possibly
+	 * compressed) data fits in a leaf and the configured maximum inline
+	 * size.
+	 */
+	if (size < i_size_read(&inode->vfs_inode) ||
+	    size > fs_info->sectorsize ||
 	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
-	    (!compressed_size &&
-	    (actual_end & (fs_info->sectorsize - 1)) == 0) ||
-	    end + 1 < isize ||
-	    data_len > fs_info->max_inline) {
+	    data_len > fs_info->max_inline)
 		return 1;
-	}
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -380,30 +381,21 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 	trans->block_rsv = &inode->block_rsv;
 
 	drop_args.path = path;
-	drop_args.start = start;
-	drop_args.end = aligned_end;
+	drop_args.start = 0;
+	drop_args.end = fs_info->sectorsize;
 	drop_args.drop_cache = true;
 	drop_args.replace_extent = true;
-
-	if (compressed_size && compressed_pages)
-		drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
-		   compressed_size);
-	else
-		drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(
-		    inline_len);
-
+	drop_args.extent_item_size = btrfs_file_extent_calc_inline_size(data_len);
 	ret = btrfs_drop_extents(trans, root, inode, &drop_args);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;
 	}
 
-	if (isize > actual_end)
-		inline_len = min_t(u64, isize, actual_end);
-	ret = insert_inline_extent(trans, path, drop_args.extent_inserted,
-				   root, &inode->vfs_inode, start,
-				   inline_len, compressed_size,
-				   compress_type, compressed_pages);
+	ret = insert_inline_extent(trans, path, drop_args.extent_inserted, root,
+				   &inode->vfs_inode, size, compressed_size,
+				   compress_type, compressed_pages,
+				   update_i_size);
 	if (ret && ret != -ENOSPC) {
 		btrfs_abort_transaction(trans, ret);
 		goto out;
@@ -412,7 +404,7 @@ static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
 		goto out;
 	}
 
-	btrfs_update_inode_bytes(inode, inline_len, drop_args.bytes_found);
+	btrfs_update_inode_bytes(inode, size, drop_args.bytes_found);
 	ret = btrfs_update_inode(trans, root, inode);
 	if (ret && ret != -ENOSPC) {
 		btrfs_abort_transaction(trans, ret);
@@ -695,14 +687,15 @@ static noinline int compress_file_range(struct async_chunk *async_chunk)
 			/* we didn't compress the entire range, try
 			 * to make an uncompressed inline extent.
 			 */
-			ret = cow_file_range_inline(BTRFS_I(inode), start, end,
+			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
 						    0, BTRFS_COMPRESS_NONE,
-						    NULL);
+						    NULL, false);
 		} else {
 			/* try making a compressed inline extent */
-			ret = cow_file_range_inline(BTRFS_I(inode), start, end,
+			ret = cow_file_range_inline(BTRFS_I(inode), actual_end,
 						    total_compressed,
-						    compress_type, pages);
+						    compress_type, pages,
+						    false);
 		}
 		if (ret <= 0) {
 			unsigned long clear_flags = EXTENT_DELALLOC |
@@ -1098,9 +1091,12 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 	 * So here we skip inline extent creation completely.
 	 */
 	if (start == 0 && fs_info->sectorsize == PAGE_SIZE) {
+		u64 actual_end = min_t(u64, i_size_read(&inode->vfs_inode),
+				       end + 1);
+
 		/* lets try to make an inline extent */
-		ret = cow_file_range_inline(inode, start, end, 0,
-					    BTRFS_COMPRESS_NONE, NULL);
+		ret = cow_file_range_inline(inode, actual_end, 0,
+					    BTRFS_COMPRESS_NONE, NULL, false);
 		if (ret == 0) {
 			/*
 			 * We use DO_ACCOUNTING here because we need the
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (5 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 06/14] btrfs: optionally extend i_size in cow_file_range_inline() Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-15  9:42   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ Omar Sandoval
                   ` (16 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

In order to allow sending and receiving compressed data without
decompressing it, we need an interface to write pre-compressed data
directly to the filesystem and the matching interface to read compressed
data without decompressing it. This adds the definitions for ioctls to
do that and detailed explanations of how to use them.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 include/uapi/linux/btrfs.h | 132 +++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index d7d3cfead056..95da52955894 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -861,6 +861,134 @@ struct btrfs_ioctl_get_subvol_rootref_args {
 		__u8 align[7];
 };
 
+/*
+ * Data and metadata for an encoded read or write.
+ *
+ * Encoded I/O bypasses any encoding automatically done by the filesystem (e.g.,
+ * compression). This can be used to read the compressed contents of a file or
+ * write pre-compressed data directly to a file.
+ *
+ * BTRFS_IOC_ENCODED_READ and BTRFS_IOC_ENCODED_WRITE are essentially
+ * preadv/pwritev with additional metadata about how the data is encoded and the
+ * size of the unencoded data.
+ *
+ * BTRFS_IOC_ENCODED_READ fills the given iovecs with the encoded data, fills
+ * the metadata fields, and returns the size of the encoded data. It reads one
+ * extent per call. It can also read data which is not encoded.
+ *
+ * BTRFS_IOC_ENCODED_WRITE uses the metadata fields, writes the encoded data
+ * from the iovecs, and returns the size of the encoded data. Note that the
+ * encoded data is not validated when it is written; if it is not valid (e.g.,
+ * it cannot be decompressed), then a subsequent read may return an error.
+ *
+ * Since the filesystem page cache contains decoded data, encoded I/O bypasses
+ * the page cache. Encoded I/O requires CAP_SYS_ADMIN.
+ */
+struct btrfs_ioctl_encoded_io_args {
+	/* Input parameters for both reads and writes. */
+
+	/*
+	 * iovecs containing encoded data.
+	 *
+	 * For reads, if the size of the encoded data is larger than the sum of
+	 * iov[n].iov_len for 0 <= n < iovcnt, then the ioctl fails with
+	 * ENOBUFS.
+	 *
+	 * For writes, the size of the encoded data is the sum of iov[n].iov_len
+	 * for 0 <= n < iovcnt. This must be less than 128 KiB (this limit may
+	 * increase in the future). This must also be less than or equal to
+	 * unencoded_len.
+	 */
+	const struct iovec __user *iov;
+	/* Number of iovecs. */
+	unsigned long iovcnt;
+	/*
+	 * Offset in file.
+	 *
+	 * For writes, must be aligned to the sector size of the filesystem.
+	 */
+	__s64 offset;
+	/* Currently must be zero. */
+	__u64 flags;
+
+	/*
+	 * For reads, the following members are filled in with the metadata for
+	 * the encoded data.
+	 * For writes, the following members must be set to the metadata for the
+	 * encoded data.
+	 */
+
+	/*
+	 * Length of the data in the file.
+	 *
+	 * Must be less than or equal to unencoded_len - unencoded_offset. For
+	 * writes, must be aligned to the sector size of the filesystem unless
+	 * the data ends at or beyond the current end of the file.
+	 */
+	__u64 len;
+	/*
+	 * Length of the unencoded (i.e., decrypted and decompressed) data.
+	 *
+	 * For writes, must be no more than 128 KiB (this limit may increase in
+	 * the future). If the unencoded data is actually longer than
+	 * unencoded_len, then it is truncated; if it is shorter, then it is
+	 * extended with zeroes.
+	 */
+	__u64 unencoded_len;
+	/*
+	 * Offset from the first byte of the unencoded data to the first byte of
+	 * logical data in the file.
+	 *
+	 * Must be less than unencoded_len.
+	 */
+	__u64 unencoded_offset;
+	/*
+	 * BTRFS_ENCODED_IO_COMPRESSION_* type.
+	 *
+	 * For writes, must not be BTRFS_ENCODED_IO_COMPRESSION_NONE.
+	 */
+	__u32 compression;
+	/* Currently always BTRFS_ENCODED_IO_ENCRYPTION_NONE. */
+	__u32 encryption;
+	/*
+	 * Reserved for future expansion.
+	 *
+	 * For reads, always returned as zero. Users should check for non-zero
+	 * bytes. If there are any, then the kernel has a newer version of this
+	 * structure with additional information that the user definition is
+	 * missing.
+	 *
+	 * For writes, must be zeroed.
+	 */
+	__u8 reserved[32];
+};
+
+/* Data is not compressed. */
+#define BTRFS_ENCODED_IO_COMPRESSION_NONE 0
+/* Data is compressed as a single zlib stream. */
+#define BTRFS_ENCODED_IO_COMPRESSION_ZLIB 1
+/*
+ * Data is compressed as a single zstd frame with the windowLog compression
+ * parameter set to no more than 17.
+ */
+#define BTRFS_ENCODED_IO_COMPRESSION_ZSTD 2
+/*
+ * Data is compressed page by page (using the page size indicated by the name of
+ * the constant) with LZO1X and wrapped in the format documented in
+ * fs/btrfs/lzo.c. For writes, the compression page size must match the
+ * filesystem page size.
+ */
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_4K 3
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_8K 4
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_16K 5
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_32K 6
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_64K 7
+#define BTRFS_ENCODED_IO_COMPRESSION_TYPES 8
+
+/* Data is not encrypted. */
+#define BTRFS_ENCODED_IO_ENCRYPTION_NONE 0
+#define BTRFS_ENCODED_IO_ENCRYPTION_TYPES 1
+
 /* Error codes as returned by the kernel */
 enum btrfs_err_code {
 	BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET = 1,
@@ -989,5 +1117,9 @@ enum btrfs_err_code {
 				struct btrfs_ioctl_ino_lookup_user_args)
 #define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \
 				struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_ENCODED_READ _IOR(BTRFS_IOCTL_MAGIC, 64, \
+				    struct btrfs_ioctl_encoded_io_args)
+#define BTRFS_IOC_ENCODED_WRITE _IOW(BTRFS_IOCTL_MAGIC, 64, \
+				     struct btrfs_ioctl_encoded_io_args)
 
 #endif /* _UAPI_LINUX_BTRFS_H */
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (6 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-15 11:45   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 09/14] btrfs: add BTRFS_IOC_ENCODED_WRITE Omar Sandoval
                   ` (15 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

There are 4 main cases:

1. Inline extents: we copy the data straight out of the extent buffer.
2. Hole/preallocated extents: we fill in zeroes.
3. Regular, uncompressed extents: we read the sectors we need directly
   from disk.
4. Regular, compressed extents: we read the entire compressed extent
   from disk and indicate what subset of the decompressed extent is in
   the file.

This initial implementation simplifies a few things that can be improved
in the future:

- We hold the inode lock during the operation.
- Cases 1, 3, and 4 allocate temporary memory to read into before
  copying out to userspace.
- We don't do read repair, because it turns out that read repair is
  currently broken for compressed data.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/ctree.h |   4 +
 fs/btrfs/inode.c | 489 +++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/ioctl.c | 111 +++++++++++
 3 files changed, 604 insertions(+)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b95ec5fb68d5..cbd7e07c1c34 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3223,6 +3223,10 @@ int btrfs_writepage_cow_fixup(struct page *page);
 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
 					  struct page *page, u64 start,
 					  u64 end, bool uptodate);
+struct btrfs_ioctl_encoded_io_args;
+ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
+			   struct btrfs_ioctl_encoded_io_args *encoded);
+
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
 extern const struct iomap_dio_ops btrfs_dio_ops;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a87a34f56234..1940f22179ba 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10500,6 +10500,495 @@ void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
 	}
 }
 
+static int btrfs_encoded_io_compression_from_extent(int compress_type)
+{
+	switch (compress_type) {
+	case BTRFS_COMPRESS_NONE:
+		return BTRFS_ENCODED_IO_COMPRESSION_NONE;
+	case BTRFS_COMPRESS_ZLIB:
+		return BTRFS_ENCODED_IO_COMPRESSION_ZLIB;
+	case BTRFS_COMPRESS_LZO:
+		/*
+		 * The LZO format depends on the page size. 64k is the maximum
+		 * sectorsize (and thus page size) that we support.
+		 */
+		if (PAGE_SIZE < SZ_4K || PAGE_SIZE > SZ_64K)
+			return -EINVAL;
+		return BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + (PAGE_SHIFT - 12);
+	case BTRFS_COMPRESS_ZSTD:
+		return BTRFS_ENCODED_IO_COMPRESSION_ZSTD;
+	default:
+		return -EUCLEAN;
+	}
+}
+
+static ssize_t btrfs_encoded_read_inline(
+				struct kiocb *iocb,
+				struct iov_iter *iter, u64 start,
+				u64 lockend,
+				struct extent_state **cached_state,
+				u64 extent_start, size_t count,
+				struct btrfs_ioctl_encoded_io_args *encoded,
+				bool *unlocked)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	struct btrfs_file_extent_item *item;
+	u64 ram_bytes;
+	unsigned long ptr;
+	void *tmp;
+	ssize_t ret;
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root, path,
+				       btrfs_ino(BTRFS_I(inode)), extent_start,
+				       0);
+	if (ret) {
+		if (ret > 0) {
+			/* The extent item disappeared? */
+			ret = -EIO;
+		}
+		goto out;
+	}
+	leaf = path->nodes[0];
+	item = btrfs_item_ptr(leaf, path->slots[0],
+			      struct btrfs_file_extent_item);
+
+	ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
+	ptr = btrfs_file_extent_inline_start(item);
+
+	encoded->len = (min_t(u64, extent_start + ram_bytes, inode->i_size) -
+			iocb->ki_pos);
+	ret = btrfs_encoded_io_compression_from_extent(
+				 btrfs_file_extent_compression(leaf, item));
+	if (ret < 0)
+		goto out;
+	encoded->compression = ret;
+	if (encoded->compression) {
+		size_t inline_size;
+
+		inline_size = btrfs_file_extent_inline_item_len(leaf,
+						btrfs_item_nr(path->slots[0]));
+		if (inline_size > count) {
+			ret = -ENOBUFS;
+			goto out;
+		}
+		count = inline_size;
+		encoded->unencoded_len = ram_bytes;
+		encoded->unencoded_offset = iocb->ki_pos - extent_start;
+	} else {
+		encoded->len = encoded->unencoded_len = count =
+			min_t(u64, count, encoded->len);
+		ptr += iocb->ki_pos - extent_start;
+	}
+
+	tmp = kmalloc(count, GFP_NOFS);
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	read_extent_buffer(leaf, tmp, ptr, count);
+	btrfs_release_path(path);
+	unlock_extent_cached(io_tree, start, lockend, cached_state);
+	inode_unlock_shared(inode);
+	*unlocked = true;
+
+	ret = copy_to_iter(tmp, count, iter);
+	if (ret != count)
+		ret = -EFAULT;
+	kfree(tmp);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+struct btrfs_encoded_read_private {
+	struct inode *inode;
+	wait_queue_head_t wait;
+	atomic_t pending;
+	blk_status_t status;
+	bool skip_csum;
+};
+
+static blk_status_t submit_encoded_read_bio(struct inode *inode,
+					    struct bio *bio, int mirror_num,
+					    unsigned long bio_flags)
+{
+	struct btrfs_encoded_read_private *priv = bio->bi_private;
+	struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	blk_status_t ret;
+
+	if (!priv->skip_csum) {
+		ret = btrfs_lookup_bio_sums(inode, bio, NULL);
+		if (ret)
+			return ret;
+	}
+
+	ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
+	if (ret) {
+		btrfs_io_bio_free_csum(io_bio);
+		return ret;
+	}
+
+	atomic_inc(&priv->pending);
+	ret = btrfs_map_bio(fs_info, bio, mirror_num);
+	if (ret) {
+		atomic_dec(&priv->pending);
+		btrfs_io_bio_free_csum(io_bio);
+	}
+	return ret;
+}
+
+static blk_status_t btrfs_encoded_read_check_bio(struct btrfs_io_bio *io_bio)
+{
+	const bool uptodate = io_bio->bio.bi_status == BLK_STS_OK;
+	struct btrfs_encoded_read_private *priv = io_bio->bio.bi_private;
+	struct inode *inode = priv->inode;
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	u32 sectorsize = fs_info->sectorsize;
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
+	u64 start = io_bio->logical;
+	u32 bio_offset = 0;
+
+	if (priv->skip_csum || !uptodate)
+		return io_bio->bio.bi_status;
+
+	bio_for_each_segment_all(bvec, &io_bio->bio, iter_all) {
+		unsigned int i, nr_sectors, pgoff;
+
+		nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
+		pgoff = bvec->bv_offset;
+		for (i = 0; i < nr_sectors; i++) {
+			ASSERT(pgoff < PAGE_SIZE);
+			if (check_data_csum(inode, io_bio, bio_offset,
+					    bvec->bv_page, pgoff, start))
+				return BLK_STS_IOERR;
+			start += sectorsize;
+			bio_offset += sectorsize;
+			pgoff += sectorsize;
+		}
+	}
+	return BLK_STS_OK;
+}
+
+static void btrfs_encoded_read_endio(struct bio *bio)
+{
+	struct btrfs_encoded_read_private *priv = bio->bi_private;
+	struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
+	blk_status_t status;
+
+	status = btrfs_encoded_read_check_bio(io_bio);
+	if (status) {
+		/*
+		 * The memory barrier implied by the atomic_dec_return() here
+		 * pairs with the memory barrier implied by the
+		 * atomic_dec_return() or io_wait_event() in
+		 * btrfs_encoded_read_regular_fill_pages() to ensure that this
+		 * write is observed before the load of status in
+		 * btrfs_encoded_read_regular_fill_pages().
+		 */
+		WRITE_ONCE(priv->status, status);
+	}
+	if (!atomic_dec_return(&priv->pending))
+		wake_up(&priv->wait);
+	btrfs_io_bio_free_csum(io_bio);
+	bio_put(bio);
+}
+
+static int btrfs_encoded_read_regular_fill_pages(struct inode *inode, u64 offset,
+						 u64 disk_io_size, struct page **pages)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_encoded_read_private priv = {
+		.inode = inode,
+		.pending = ATOMIC_INIT(1),
+		.skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM,
+	};
+	unsigned long i = 0;
+	u64 cur = 0;
+	int ret;
+
+	init_waitqueue_head(&priv.wait);
+	/*
+	 * Submit bios for the extent, splitting due to bio or stripe limits as
+	 * necessary.
+	 */
+	while (cur < disk_io_size) {
+		struct extent_map *em;
+		struct btrfs_io_geometry geom;
+		struct bio *bio = NULL;
+		u64 remaining;
+
+		em = btrfs_get_chunk_map(fs_info, offset + cur,
+					 disk_io_size - cur);
+		if (IS_ERR(em)) {
+			ret = PTR_ERR(em);
+		} else {
+			ret = btrfs_get_io_geometry(fs_info, em, BTRFS_MAP_READ,
+						    offset + cur, &geom);
+			free_extent_map(em);
+		}
+		if (ret) {
+			WRITE_ONCE(priv.status, errno_to_blk_status(ret));
+			break;
+		}
+		remaining = min(geom.len, disk_io_size - cur);
+		while (bio || remaining) {
+			size_t bytes = min_t(u64, remaining, PAGE_SIZE);
+
+			if (!bio) {
+				bio = btrfs_bio_alloc(offset + cur);
+				bio->bi_end_io = btrfs_encoded_read_endio;
+				bio->bi_private = &priv;
+				bio->bi_opf = REQ_OP_READ;
+			}
+
+			if (!bytes ||
+			    bio_add_page(bio, pages[i], bytes, 0) < bytes) {
+				blk_status_t status;
+
+				status = submit_encoded_read_bio(inode, bio, 0,
+								 0);
+				if (status) {
+					WRITE_ONCE(priv.status, status);
+					bio_put(bio);
+					goto out;
+				}
+				bio = NULL;
+				continue;
+			}
+
+			i++;
+			cur += bytes;
+			remaining -= bytes;
+		}
+	}
+
+out:
+	if (atomic_dec_return(&priv.pending))
+		io_wait_event(priv.wait, !atomic_read(&priv.pending));
+	/* See btrfs_encoded_read_endio() for ordering. */
+	return blk_status_to_errno(READ_ONCE(priv.status));
+}
+
+static ssize_t btrfs_encoded_read_regular(struct kiocb *iocb,
+					  struct iov_iter *iter,
+					  u64 start, u64 lockend,
+					  struct extent_state **cached_state,
+					  u64 offset, u64 disk_io_size,
+					  size_t count, bool compressed,
+					  bool *unlocked)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct page **pages;
+	unsigned long nr_pages, i;
+	u64 cur;
+	size_t page_offset;
+	ssize_t ret;
+
+	nr_pages = DIV_ROUND_UP(disk_io_size, PAGE_SIZE);
+	pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
+	if (!pages)
+		return -ENOMEM;
+	for (i = 0; i < nr_pages; i++) {
+		pages[i] = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+		if (!pages[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
+
+	ret = btrfs_encoded_read_regular_fill_pages(inode, offset, disk_io_size,
+						    pages);
+	if (ret)
+		goto out;
+
+	unlock_extent_cached(io_tree, start, lockend, cached_state);
+	inode_unlock_shared(inode);
+	*unlocked = true;
+
+	if (compressed) {
+		i = 0;
+		page_offset = 0;
+	} else {
+		i = (iocb->ki_pos - start) >> PAGE_SHIFT;
+		page_offset = (iocb->ki_pos - start) & (PAGE_SIZE - 1);
+	}
+	cur = 0;
+	while (cur < count) {
+		size_t bytes = min_t(size_t, count - cur,
+				     PAGE_SIZE - page_offset);
+
+		if (copy_page_to_iter(pages[i], page_offset, bytes,
+				      iter) != bytes) {
+			ret = -EFAULT;
+			goto out;
+		}
+		i++;
+		cur += bytes;
+		page_offset = 0;
+	}
+	ret = count;
+out:
+	for (i = 0; i < nr_pages; i++) {
+		if (pages[i])
+			__free_page(pages[i]);
+	}
+	kfree(pages);
+	return ret;
+}
+
+ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
+			   struct btrfs_ioctl_encoded_io_args *encoded)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	ssize_t ret;
+	size_t count = iov_iter_count(iter);
+	u64 start, lockend, offset, disk_io_size;
+	struct extent_state *cached_state = NULL;
+	struct extent_map *em;
+	bool unlocked = false;
+
+	file_accessed(iocb->ki_filp);
+
+	inode_lock_shared(inode);
+
+	if (iocb->ki_pos >= inode->i_size) {
+		inode_unlock_shared(inode);
+		return 0;
+	}
+	start = ALIGN_DOWN(iocb->ki_pos, fs_info->sectorsize);
+	/*
+	 * We don't know how long the extent containing iocb->ki_pos is, but if
+	 * it's compressed we know that it won't be longer than this.
+	 */
+	lockend = start + BTRFS_MAX_UNCOMPRESSED - 1;
+
+	for (;;) {
+		struct btrfs_ordered_extent *ordered;
+
+		ret = btrfs_wait_ordered_range(inode, start,
+					       lockend - start + 1);
+		if (ret)
+			goto out_unlock_inode;
+		lock_extent_bits(io_tree, start, lockend, &cached_state);
+		ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
+						     lockend - start + 1);
+		if (!ordered)
+			break;
+		btrfs_put_ordered_extent(ordered);
+		unlock_extent_cached(io_tree, start, lockend, &cached_state);
+		cond_resched();
+	}
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start,
+			      lockend - start + 1);
+	if (IS_ERR(em)) {
+		ret = PTR_ERR(em);
+		goto out_unlock_extent;
+	}
+
+	if (em->block_start == EXTENT_MAP_INLINE) {
+		u64 extent_start = em->start;
+
+		/*
+		 * For inline extents we get everything we need out of the
+		 * extent item.
+		 */
+		free_extent_map(em);
+		em = NULL;
+		ret = btrfs_encoded_read_inline(iocb, iter, start, lockend,
+						&cached_state, extent_start,
+						count, encoded, &unlocked);
+		goto out;
+	}
+
+	/*
+	 * We only want to return up to EOF even if the extent extends beyond
+	 * that.
+	 */
+	encoded->len = (min_t(u64, extent_map_end(em), inode->i_size) -
+			iocb->ki_pos);
+	if (em->block_start == EXTENT_MAP_HOLE ||
+	    test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
+		offset = EXTENT_MAP_HOLE;
+		encoded->len = encoded->unencoded_len = count =
+			min_t(u64, count, encoded->len);
+	} else if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
+		offset = em->block_start;
+		/*
+		 * Bail if the buffer isn't large enough to return the whole
+		 * compressed extent.
+		 */
+		if (em->block_len > count) {
+			ret = -ENOBUFS;
+			goto out_em;
+		}
+		disk_io_size = count = em->block_len;
+		encoded->unencoded_len = em->ram_bytes;
+		encoded->unencoded_offset = iocb->ki_pos - em->orig_start;
+		ret = btrfs_encoded_io_compression_from_extent(
+							     em->compress_type);
+		if (ret < 0)
+			goto out_em;
+		encoded->compression = ret;
+	} else {
+		offset = em->block_start + (start - em->start);
+		if (encoded->len > count)
+			encoded->len = count;
+		/*
+		 * Don't read beyond what we locked. This also limits the page
+		 * allocations that we'll do.
+		 */
+		disk_io_size = min(lockend + 1,
+				   iocb->ki_pos + encoded->len) - start;
+		encoded->len = encoded->unencoded_len = count =
+			start + disk_io_size - iocb->ki_pos;
+		disk_io_size = ALIGN(disk_io_size, fs_info->sectorsize);
+	}
+	free_extent_map(em);
+	em = NULL;
+
+	if (offset == EXTENT_MAP_HOLE) {
+		unlock_extent_cached(io_tree, start, lockend, &cached_state);
+		inode_unlock_shared(inode);
+		unlocked = true;
+		ret = iov_iter_zero(count, iter);
+		if (ret != count)
+			ret = -EFAULT;
+	} else {
+		ret = btrfs_encoded_read_regular(iocb, iter, start, lockend,
+						 &cached_state, offset,
+						 disk_io_size, count,
+						 encoded->compression,
+						 &unlocked);
+	}
+
+out:
+	if (ret >= 0)
+		iocb->ki_pos += encoded->len;
+out_em:
+	free_extent_map(em);
+out_unlock_extent:
+	if (!unlocked)
+		unlock_extent_cached(io_tree, start, lockend, &cached_state);
+out_unlock_inode:
+	if (!unlocked)
+		inode_unlock_shared(inode);
+	return ret;
+}
+
 #ifdef CONFIG_SWAP
 /*
  * Add an entry indicating a block group or device which is pinned by a
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fecb8bac11dd..4e619a10f236 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -28,6 +28,7 @@
 #include <linux/iversion.h>
 #include <linux/fileattr.h>
 #include <linux/fsverity.h>
+#include <linux/sched/xacct.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "export.h"
@@ -87,6 +88,22 @@ struct btrfs_ioctl_send_args_32 {
 
 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
 			       struct btrfs_ioctl_send_args_32)
+
+struct btrfs_ioctl_encoded_io_args_32 {
+	compat_uptr_t iov;
+	compat_ulong_t iovcnt;
+	__s64 offset;
+	__u64 flags;
+	__u64 len;
+	__u64 unencoded_len;
+	__u64 unencoded_offset;
+	__u32 compression;
+	__u32 encryption;
+	__u32 reserved[8];
+};
+
+#define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
+				       struct btrfs_ioctl_encoded_io_args_32)
 #endif
 
 /* Mask out flags that are inappropriate for the given type of inode. */
@@ -4824,6 +4841,94 @@ static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
 	return ret;
 }
 
+static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp,
+				    bool compat)
+{
+	struct btrfs_ioctl_encoded_io_args args;
+	size_t copy_end_kernel = offsetofend(struct btrfs_ioctl_encoded_io_args,
+					     flags);
+	size_t copy_end;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	loff_t pos;
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		ret = -EPERM;
+		goto out_acct;
+	}
+
+	if (compat) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+		struct btrfs_ioctl_encoded_io_args_32 args32;
+
+		copy_end = offsetofend(struct btrfs_ioctl_encoded_io_args_32,
+				       flags);
+		if (copy_from_user(&args32, argp, copy_end)) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+		args.iov = compat_ptr(args32.iov);
+		args.iovcnt = args32.iovcnt;
+		args.offset = args32.offset;
+		args.flags = args32.flags;
+#else
+		return -ENOTTY;
+#endif
+	} else {
+		copy_end = copy_end_kernel;
+		if (copy_from_user(&args, argp, copy_end)) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+	}
+	if (args.flags != 0) {
+		ret = -EINVAL;
+		goto out_acct;
+	}
+	memset((char *)&args + copy_end_kernel, 0,
+	       sizeof(args) - copy_end_kernel);
+
+	ret = import_iovec(READ, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
+			   &iov, &iter);
+	if (ret < 0)
+		goto out_acct;
+
+	if (iov_iter_count(&iter) == 0) {
+		ret = 0;
+		goto out_iov;
+	}
+	pos = args.offset;
+	ret = rw_verify_area(READ, file, &pos, args.len);
+	if (ret < 0)
+		goto out_iov;
+
+	init_sync_kiocb(&kiocb, file);
+	ret = kiocb_set_rw_flags(&kiocb, 0);
+	if (ret)
+		goto out_iov;
+	kiocb.ki_pos = pos;
+
+	ret = btrfs_encoded_read(&kiocb, &iter, &args);
+	if (ret >= 0) {
+		fsnotify_access(file);
+		if (copy_to_user(argp + copy_end,
+				 (char *)&args + copy_end_kernel,
+				 sizeof(args) - copy_end_kernel))
+			ret = -EFAULT;
+	}
+
+out_iov:
+	kfree(iov);
+out_acct:
+	if (ret > 0)
+		add_rchar(current, ret);
+	inc_syscr(current);
+	return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -4968,6 +5073,12 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return fsverity_ioctl_enable(file, (const void __user *)argp);
 	case FS_IOC_MEASURE_VERITY:
 		return fsverity_ioctl_measure(file, argp);
+	case BTRFS_IOC_ENCODED_READ:
+		return btrfs_ioctl_encoded_read(file, argp, false);
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+	case BTRFS_IOC_ENCODED_READ_32:
+		return btrfs_ioctl_encoded_read(file, argp, true);
+#endif
 	}
 
 	return -ENOTTY;
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 09/14] btrfs: add BTRFS_IOC_ENCODED_WRITE
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (7 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-09-01 17:01 ` [PATCH v11 10/14] btrfs: add send stream v2 definitions Omar Sandoval
                   ` (14 subsequent siblings)
  23 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

The implementation resembles direct I/O: we have to flush any ordered
extents, invalidate the page cache, and do the io tree/delalloc/extent
map/ordered extent dance. From there, we can reuse the compression code
with a minor modification to distinguish the write from writeback. This
also creates inline extents when possible.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/compression.c  |   7 +-
 fs/btrfs/compression.h  |   6 +-
 fs/btrfs/ctree.h        |   4 +
 fs/btrfs/file.c         |  65 ++++++++--
 fs/btrfs/inode.c        | 256 +++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/ioctl.c        | 102 ++++++++++++++++
 fs/btrfs/ordered-data.c |  12 +-
 fs/btrfs/ordered-data.h |   5 +-
 8 files changed, 437 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index e645b3c2f09a..a9845aab3b18 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -353,7 +353,8 @@ static void end_compressed_bio_write(struct bio *bio)
 			cb->start, cb->start + cb->len - 1,
 			!cb->errors);
 
-	end_compressed_writeback(inode, cb);
+	if (cb->writeback)
+		end_compressed_writeback(inode, cb);
 	/* note, our inode could be gone now */
 
 	/*
@@ -389,7 +390,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				 struct page **compressed_pages,
 				 unsigned int nr_pages,
 				 unsigned int write_flags,
-				 struct cgroup_subsys_state *blkcg_css)
+				 struct cgroup_subsys_state *blkcg_css,
+				 bool writeback)
 {
 	struct btrfs_fs_info *fs_info = inode->root->fs_info;
 	struct bio *bio = NULL;
@@ -415,6 +417,7 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 	cb->mirror_num = 0;
 	cb->compressed_pages = compressed_pages;
 	cb->compressed_len = compressed_len;
+	cb->writeback = writeback;
 	cb->orig_bio = NULL;
 	cb->nr_pages = nr_pages;
 
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index 399be0b435bf..2ba9402f308d 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -52,6 +52,9 @@ struct compressed_bio {
 	/* The compression algorithm for this bio */
 	u8 compress_type;
 
+	/* Whether this is a write for writeback. */
+	bool writeback;
+
 	/* IO errors */
 	u8 errors;
 	int mirror_num;
@@ -95,7 +98,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
 				  struct page **compressed_pages,
 				  unsigned int nr_pages,
 				  unsigned int write_flags,
-				  struct cgroup_subsys_state *blkcg_css);
+				  struct cgroup_subsys_state *blkcg_css,
+				  bool writeback);
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags);
 
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index cbd7e07c1c34..7753976bc3c7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3226,6 +3226,8 @@ void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
 struct btrfs_ioctl_encoded_io_args;
 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
 			   struct btrfs_ioctl_encoded_io_args *encoded);
+ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			     const struct btrfs_ioctl_encoded_io_args *encoded);
 
 extern const struct dentry_operations btrfs_dentry_operations;
 extern const struct iomap_ops btrfs_dio_iomap_ops;
@@ -3286,6 +3288,8 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
 			   struct btrfs_trans_handle **trans_out);
 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
 			      struct btrfs_inode *inode, u64 start, u64 end);
+ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from,
+			    const struct btrfs_ioctl_encoded_io_args *encoded);
 int btrfs_release_file(struct inode *inode, struct file *file);
 int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
 		      size_t num_pages, loff_t pos, size_t write_bytes,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 6f9cb8baffd2..8b58fc690866 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2001,12 +2001,43 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
 	return written ? written : err;
 }
 
-static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
-				    struct iov_iter *from)
+static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			const struct btrfs_ioctl_encoded_io_args *encoded)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	loff_t count;
+	ssize_t ret;
+
+	btrfs_inode_lock(inode, 0);
+	count = encoded->len;
+	ret = generic_write_checks_count(iocb, &count);
+	if (ret == 0 && count != encoded->len) {
+		/*
+		 * The write got truncated by generic_write_checks_count(). We
+		 * can't do a partial encoded write.
+		 */
+		ret = -EFBIG;
+	}
+	if (ret || encoded->len == 0)
+		goto out;
+
+	ret = btrfs_write_check(iocb, from, encoded->len);
+	if (ret < 0)
+		goto out;
+
+	ret = btrfs_do_encoded_write(iocb, from, encoded);
+out:
+	btrfs_inode_unlock(inode, 0);
+	return ret;
+}
+
+ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from,
+			    const struct btrfs_ioctl_encoded_io_args *encoded)
 {
 	struct file *file = iocb->ki_filp;
 	struct btrfs_inode *inode = BTRFS_I(file_inode(file));
-	ssize_t num_written = 0;
+	ssize_t num_written, num_sync;
 	const bool sync = iocb->ki_flags & IOCB_DSYNC;
 
 	/*
@@ -2017,22 +2048,28 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	if (test_bit(BTRFS_FS_STATE_ERROR, &inode->root->fs_info->fs_state))
 		return -EROFS;
 
-	if (!(iocb->ki_flags & IOCB_DIRECT) &&
-	    (iocb->ki_flags & IOCB_NOWAIT))
+	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
 		return -EOPNOTSUPP;
 
 	if (sync)
 		atomic_inc(&inode->sync_writers);
 
-	if (iocb->ki_flags & IOCB_DIRECT)
-		num_written = btrfs_direct_write(iocb, from);
-	else
-		num_written = btrfs_buffered_write(iocb, from);
+	if (encoded) {
+		num_written = btrfs_encoded_write(iocb, from, encoded);
+		num_sync = encoded->len;
+	} else if (iocb->ki_flags & IOCB_DIRECT) {
+		num_written = num_sync = btrfs_direct_write(iocb, from);
+	} else {
+		num_written = num_sync = btrfs_buffered_write(iocb, from);
+	}
 
 	btrfs_set_inode_last_sub_trans(inode);
 
-	if (num_written > 0)
-		num_written = generic_write_sync(iocb, num_written);
+	if (num_sync > 0) {
+		num_sync = generic_write_sync(iocb, num_sync);
+		if (num_sync < 0)
+			num_written = num_sync;
+	}
 
 	if (sync)
 		atomic_dec(&inode->sync_writers);
@@ -2041,6 +2078,12 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	return num_written;
 }
 
+static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
+				    struct iov_iter *from)
+{
+	return btrfs_do_write_iter(iocb, from, NULL);
+}
+
 int btrfs_release_file(struct inode *inode, struct file *filp)
 {
 	struct btrfs_file_private *private = filp->private_data;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1940f22179ba..e751af96c198 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -966,7 +966,7 @@ static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
 				    ins.offset, async_extent->pages,
 				    async_extent->nr_pages,
 				    async_chunk->write_flags,
-				    async_chunk->blkcg_css)) {
+				    async_chunk->blkcg_css, true)) {
 			struct page *p = async_extent->pages[0];
 			const u64 start = async_extent->start;
 			const u64 end = start + async_extent->ram_size - 1;
@@ -2967,6 +2967,7 @@ static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans,
 	 * except if the ordered extent was truncated.
 	 */
 	update_inode_bytes = test_bit(BTRFS_ORDERED_DIRECT, &oe->flags) ||
+			     test_bit(BTRFS_ORDERED_ENCODED, &oe->flags) ||
 			     test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags);
 
 	return insert_reserved_file_extent(trans, BTRFS_I(oe->inode),
@@ -3001,7 +3002,8 @@ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
 
 	if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
 	    !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
-	    !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
+	    !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags) &&
+	    !test_bit(BTRFS_ORDERED_ENCODED, &ordered_extent->flags))
 		clear_bits |= EXTENT_DELALLOC_NEW;
 
 	freespace_inode = btrfs_is_free_space_inode(inode);
@@ -10989,6 +10991,256 @@ ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
 	return ret;
 }
 
+ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
+			      const struct btrfs_ioctl_encoded_io_args *encoded)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	struct btrfs_root *root = BTRFS_I(inode)->root;
+	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+	struct extent_changeset *data_reserved = NULL;
+	struct extent_state *cached_state = NULL;
+	int compression;
+	size_t orig_count;
+	u64 start, end;
+	u64 num_bytes, ram_bytes, disk_num_bytes;
+	unsigned long nr_pages, i;
+	struct page **pages;
+	struct btrfs_key ins;
+	bool extent_reserved = false;
+	struct extent_map *em;
+	ssize_t ret;
+
+	switch (encoded->compression) {
+	case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
+		compression = BTRFS_COMPRESS_ZLIB;
+		break;
+	case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
+		compression = BTRFS_COMPRESS_ZSTD;
+		break;
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
+		/* The page size must match for LZO. */
+		if (encoded->compression -
+		    BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12 != PAGE_SHIFT)
+			return -EINVAL;
+		compression = BTRFS_COMPRESS_LZO;
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (encoded->encryption != BTRFS_ENCODED_IO_ENCRYPTION_NONE)
+		return -EINVAL;
+
+	orig_count = iov_iter_count(from);
+
+	/* The extent size must be sane. */
+	if (encoded->unencoded_len > BTRFS_MAX_UNCOMPRESSED ||
+	    orig_count > BTRFS_MAX_COMPRESSED || orig_count == 0)
+		return -EINVAL;
+
+	/*
+	 * The compressed data must be smaller than the decompressed data.
+	 *
+	 * It's of course possible for data to compress to larger or the same
+	 * size, but the buffered I/O path falls back to no compression for such
+	 * data, and we don't want to break any assumptions by creating these
+	 * extents.
+	 *
+	 * Note that this is less strict than the current check we have that the
+	 * compressed data must be at least one sector smaller than the
+	 * decompressed data. We only want to enforce the weaker requirement
+	 * from old kernels that it is at least one byte smaller.
+	 */
+	if (orig_count >= encoded->unencoded_len)
+		return -EINVAL;
+
+	/* The extent must start on a sector boundary. */
+	start = iocb->ki_pos;
+	if (!IS_ALIGNED(start, fs_info->sectorsize))
+		return -EINVAL;
+
+	/*
+	 * The extent must end on a sector boundary. However, we allow a write
+	 * which ends at or extends i_size to have an unaligned length; we round
+	 * up the extent size and set i_size to the unaligned end.
+	 */
+	if (start + encoded->len < inode->i_size &&
+	    !IS_ALIGNED(start + encoded->len, fs_info->sectorsize))
+		return -EINVAL;
+
+	/* Finally, the offset in the unencoded data must be sector-aligned. */
+	if (!IS_ALIGNED(encoded->unencoded_offset, fs_info->sectorsize))
+		return -EINVAL;
+
+	num_bytes = ALIGN(encoded->len, fs_info->sectorsize);
+	ram_bytes = ALIGN(encoded->unencoded_len, fs_info->sectorsize);
+	end = start + num_bytes - 1;
+
+	/*
+	 * If the extent cannot be inline, the compressed data on disk must be
+	 * sector-aligned. For convenience, we extend it with zeroes if it
+	 * isn't.
+	 */
+	disk_num_bytes = ALIGN(orig_count, fs_info->sectorsize);
+	nr_pages = DIV_ROUND_UP(disk_num_bytes, PAGE_SIZE);
+	pages = kvcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL_ACCOUNT);
+	if (!pages)
+		return -ENOMEM;
+	for (i = 0; i < nr_pages; i++) {
+		size_t bytes = min_t(size_t, PAGE_SIZE, iov_iter_count(from));
+		char *kaddr;
+
+		pages[i] = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM);
+		if (!pages[i]) {
+			ret = -ENOMEM;
+			goto out_pages;
+		}
+		kaddr = kmap(pages[i]);
+		if (copy_from_iter(kaddr, bytes, from) != bytes) {
+			kunmap(pages[i]);
+			ret = -EFAULT;
+			goto out_pages;
+		}
+		if (bytes < PAGE_SIZE)
+			memset(kaddr + bytes, 0, PAGE_SIZE - bytes);
+		kunmap(pages[i]);
+	}
+
+	for (;;) {
+		struct btrfs_ordered_extent *ordered;
+
+		ret = btrfs_wait_ordered_range(inode, start, num_bytes);
+		if (ret)
+			goto out_pages;
+		ret = invalidate_inode_pages2_range(inode->i_mapping,
+						    start >> PAGE_SHIFT,
+						    end >> PAGE_SHIFT);
+		if (ret)
+			goto out_pages;
+		lock_extent_bits(io_tree, start, end, &cached_state);
+		ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
+						     num_bytes);
+		if (!ordered &&
+		    !filemap_range_has_page(inode->i_mapping, start, end))
+			break;
+		if (ordered)
+			btrfs_put_ordered_extent(ordered);
+		unlock_extent_cached(io_tree, start, end, &cached_state);
+		cond_resched();
+	}
+
+	/*
+	 * We don't use the higher-level delalloc space functions because our
+	 * num_bytes and disk_num_bytes are different.
+	 */
+	ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), disk_num_bytes);
+	if (ret)
+		goto out_unlock;
+	ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved, start,
+					num_bytes);
+	if (ret)
+		goto out_free_data_space;
+	ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), num_bytes,
+					      disk_num_bytes);
+	if (ret)
+		goto out_qgroup_free_data;
+
+	/* Try an inline extent first. */
+	if (start == 0 && encoded->unencoded_len == encoded->len &&
+	    encoded->unencoded_offset == 0) {
+		ret = cow_file_range_inline(BTRFS_I(inode), encoded->len,
+					    orig_count, compression, pages,
+					    true);
+		if (ret <= 0) {
+			if (ret == 0)
+				ret = orig_count;
+			goto out_delalloc_release;
+		}
+	}
+
+	ret = btrfs_reserve_extent(root, disk_num_bytes, disk_num_bytes,
+				   disk_num_bytes, 0, 0, &ins, 1, 1);
+	if (ret)
+		goto out_delalloc_release;
+	extent_reserved = true;
+
+	em = create_io_em(BTRFS_I(inode), start, num_bytes,
+			  start - encoded->unencoded_offset, ins.objectid,
+			  ins.offset, ins.offset, ram_bytes, compression,
+			  BTRFS_ORDERED_COMPRESSED);
+	if (IS_ERR(em)) {
+		ret = PTR_ERR(em);
+		goto out_free_reserved;
+	}
+	free_extent_map(em);
+
+	ret = btrfs_add_ordered_extent(BTRFS_I(inode), start, num_bytes,
+				       ram_bytes, ins.objectid, ins.offset,
+				       encoded->unencoded_offset,
+				       (1 << BTRFS_ORDERED_ENCODED) |
+				       (1 << BTRFS_ORDERED_COMPRESSED),
+				       compression);
+	if (ret) {
+		btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
+		goto out_free_reserved;
+	}
+	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
+
+	if (start + encoded->len > inode->i_size)
+		i_size_write(inode, start + encoded->len);
+
+	unlock_extent_cached(io_tree, start, end, &cached_state);
+
+	btrfs_delalloc_release_extents(BTRFS_I(inode), num_bytes);
+
+	if (btrfs_submit_compressed_write(BTRFS_I(inode), start, num_bytes,
+					  ins.objectid, ins.offset, pages,
+					  nr_pages, 0, NULL, false)) {
+		btrfs_writepage_endio_finish_ordered(BTRFS_I(inode), pages[0],
+						     start, end, 0);
+		ret = -EIO;
+		goto out_pages;
+	}
+	ret = orig_count;
+	goto out;
+
+out_free_reserved:
+	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
+	btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
+out_delalloc_release:
+	btrfs_delalloc_release_extents(BTRFS_I(inode), num_bytes);
+	btrfs_delalloc_release_metadata(BTRFS_I(inode), disk_num_bytes,
+					ret < 0);
+out_qgroup_free_data:
+	if (ret < 0) {
+		btrfs_qgroup_free_data(BTRFS_I(inode), data_reserved, start,
+				       num_bytes);
+	}
+out_free_data_space:
+	/*
+	 * If btrfs_reserve_extent() succeeded, then we already decremented
+	 * bytes_may_use.
+	 */
+	if (!extent_reserved)
+		btrfs_free_reserved_data_space_noquota(fs_info, disk_num_bytes);
+out_unlock:
+	unlock_extent_cached(io_tree, start, end, &cached_state);
+out_pages:
+	for (i = 0; i < nr_pages; i++) {
+		if (pages[i])
+			__free_page(pages[i]);
+	}
+	kvfree(pages);
+out:
+	if (ret >= 0)
+		iocb->ki_pos += encoded->len;
+	return ret;
+}
+
 #ifdef CONFIG_SWAP
 /*
  * Add an entry indicating a block group or device which is pinned by a
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4e619a10f236..5a80d7b59e67 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -104,6 +104,8 @@ struct btrfs_ioctl_encoded_io_args_32 {
 
 #define BTRFS_IOC_ENCODED_READ_32 _IOR(BTRFS_IOCTL_MAGIC, 64, \
 				       struct btrfs_ioctl_encoded_io_args_32)
+#define BTRFS_IOC_ENCODED_WRITE_32 _IOW(BTRFS_IOCTL_MAGIC, 64, \
+					struct btrfs_ioctl_encoded_io_args_32)
 #endif
 
 /* Mask out flags that are inappropriate for the given type of inode. */
@@ -4929,6 +4931,102 @@ static int btrfs_ioctl_encoded_read(struct file *file, void __user *argp,
 	return ret;
 }
 
+static int btrfs_ioctl_encoded_write(struct file *file, void __user *argp,
+				     bool compat)
+{
+	struct btrfs_ioctl_encoded_io_args args;
+	struct iovec iovstack[UIO_FASTIOV];
+	struct iovec *iov = iovstack;
+	struct iov_iter iter;
+	loff_t pos;
+	struct kiocb kiocb;
+	ssize_t ret;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		ret = -EPERM;
+		goto out_acct;
+	}
+
+	if (!(file->f_mode & FMODE_WRITE)) {
+		ret = -EBADF;
+		goto out_acct;
+	}
+
+	if (compat) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+		struct btrfs_ioctl_encoded_io_args_32 args32;
+
+		if (copy_from_user(&args32, argp, sizeof(args32))) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+		args.iov = compat_ptr(args32.iov);
+		args.iovcnt = args.iovcnt;
+		memcpy(&args.offset, &args32.offset,
+		       sizeof(args) -
+		       offsetof(struct btrfs_ioctl_encoded_io_args, offset));
+#else
+		return -ENOTTY;
+#endif
+	} else {
+		if (copy_from_user(&args, argp, sizeof(args))) {
+			ret = -EFAULT;
+			goto out_acct;
+		}
+	}
+
+	ret = -EINVAL;
+	if (args.flags != 0)
+		goto out_acct;
+	if (memchr_inv(args.reserved, 0, sizeof(args.reserved)))
+		goto out_acct;
+	if (args.compression == BTRFS_ENCODED_IO_COMPRESSION_NONE &&
+	    args.encryption == BTRFS_ENCODED_IO_ENCRYPTION_NONE)
+		goto out_acct;
+	if (args.compression >= BTRFS_ENCODED_IO_COMPRESSION_TYPES ||
+	    args.encryption >= BTRFS_ENCODED_IO_ENCRYPTION_TYPES)
+		goto out_acct;
+	if (args.unencoded_offset > args.unencoded_len)
+		goto out_acct;
+	if (args.len > args.unencoded_len - args.unencoded_offset)
+		goto out_acct;
+
+	ret = import_iovec(WRITE, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
+			   &iov, &iter);
+	if (ret < 0)
+		goto out_acct;
+
+	file_start_write(file);
+
+	if (iov_iter_count(&iter) == 0) {
+		ret = 0;
+		goto out_end_write;
+	}
+	pos = args.offset;
+	ret = rw_verify_area(WRITE, file, &pos, args.len);
+	if (ret < 0)
+		goto out_end_write;
+
+	init_sync_kiocb(&kiocb, file);
+	ret = kiocb_set_rw_flags(&kiocb, 0);
+	if (ret)
+		goto out_end_write;
+	kiocb.ki_pos = pos;
+
+	ret = btrfs_do_write_iter(&kiocb, &iter, &args);
+	if (ret > 0)
+		fsnotify_modify(file);
+
+out_end_write:
+	file_end_write(file);
+	kfree(iov);
+out_acct:
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -5075,9 +5173,13 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return fsverity_ioctl_measure(file, argp);
 	case BTRFS_IOC_ENCODED_READ:
 		return btrfs_ioctl_encoded_read(file, argp, false);
+	case BTRFS_IOC_ENCODED_WRITE:
+		return btrfs_ioctl_encoded_write(file, argp, false);
 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
 	case BTRFS_IOC_ENCODED_READ_32:
 		return btrfs_ioctl_encoded_read(file, argp, true);
+	case BTRFS_IOC_ENCODED_WRITE_32:
+		return btrfs_ioctl_encoded_write(file, argp, true);
 #endif
 	}
 
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 550c34fa0e6d..180f302dee93 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -521,9 +521,15 @@ void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 	spin_lock(&btrfs_inode->lock);
 	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 	spin_unlock(&btrfs_inode->lock);
-	if (root != fs_info->tree_root)
-		btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
-						false);
+	if (root != fs_info->tree_root) {
+		u64 release;
+
+		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
+			release = entry->disk_num_bytes;
+		else
+			release = entry->num_bytes;
+		btrfs_delalloc_release_metadata(btrfs_inode, release, false);
+	}
 
 	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 				 fs_info->delalloc_batch);
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 0feb0c29839e..aeb17714ba5a 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -74,6 +74,8 @@ enum {
 	BTRFS_ORDERED_LOGGED_CSUM,
 	/* We wait for this extent to complete in the current transaction */
 	BTRFS_ORDERED_PENDING,
+	/* BTRFS_IOC_ENCODED_WRITE */
+	BTRFS_ORDERED_ENCODED,
 };
 
 /* BTRFS_ORDERED_* flags that specify the type of the extent. */
@@ -81,7 +83,8 @@ enum {
 				  (1UL << BTRFS_ORDERED_NOCOW) |	\
 				  (1UL << BTRFS_ORDERED_PREALLOC) |	\
 				  (1UL << BTRFS_ORDERED_COMPRESSED) |	\
-				  (1UL << BTRFS_ORDERED_DIRECT))
+				  (1UL << BTRFS_ORDERED_DIRECT) |	\
+				  (1UL << BTRFS_ORDERED_ENCODED))
 
 struct btrfs_ordered_extent {
 	/* logical offset in the file */
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 10/14] btrfs: add send stream v2 definitions
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (8 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 09/14] btrfs: add BTRFS_IOC_ENCODED_WRITE Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-18 12:46   ` Nikolay Borisov
  2021-10-18 15:11   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 11/14] btrfs: send: write larger chunks when using stream v2 Omar Sandoval
                   ` (13 subsequent siblings)
  23 siblings, 2 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

This adds the definitions of the new commands for send stream version 2
and their respective attributes: fallocate, FS_IOC_SETFLAGS (a.k.a.
chattr), and encoded writes. It also documents two changes to the send
stream format in v2: the receiver shouldn't assume a maximum command
size, and the DATA attribute is encoded differently to allow for writes
larger than 64k. These will be implemented in subsequent changes, and
then the ioctl will accept the new flags.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/send.c            |  2 +-
 fs/btrfs/send.h            | 30 +++++++++++++++++++++++++++++-
 include/uapi/linux/btrfs.h | 13 +++++++++++++
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index afdcbe7844e0..2ec07943f173 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -7287,7 +7287,7 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 
 	sctx->clone_roots_cnt = arg->clone_sources_count;
 
-	sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
+	sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
 	sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
 	if (!sctx->send_buf) {
 		ret = -ENOMEM;
diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
index de91488b7cd0..9f4f7b96b1eb 100644
--- a/fs/btrfs/send.h
+++ b/fs/btrfs/send.h
@@ -12,7 +12,11 @@
 #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
 #define BTRFS_SEND_STREAM_VERSION 1
 
-#define BTRFS_SEND_BUF_SIZE SZ_64K
+/*
+ * In send stream v1, no command is larger than 64k. In send stream v2, no limit
+ * should be assumed.
+ */
+#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
 
 enum btrfs_tlv_type {
 	BTRFS_TLV_U8,
@@ -76,6 +80,13 @@ enum btrfs_send_cmd {
 
 	BTRFS_SEND_C_END,
 	BTRFS_SEND_C_UPDATE_EXTENT,
+
+	/* The following commands were added in send stream v2. */
+
+	BTRFS_SEND_C_FALLOCATE,
+	BTRFS_SEND_C_SETFLAGS,
+	BTRFS_SEND_C_ENCODED_WRITE,
+
 	__BTRFS_SEND_C_MAX,
 };
 #define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
@@ -106,6 +117,11 @@ enum {
 	BTRFS_SEND_A_PATH_LINK,
 
 	BTRFS_SEND_A_FILE_OFFSET,
+	/*
+	 * In send stream v2, this attribute is special: it must be the last
+	 * attribute in a command, its header contains only the type, and its
+	 * length is implicitly the remaining length of the command.
+	 */
 	BTRFS_SEND_A_DATA,
 
 	BTRFS_SEND_A_CLONE_UUID,
@@ -114,6 +130,18 @@ enum {
 	BTRFS_SEND_A_CLONE_OFFSET,
 	BTRFS_SEND_A_CLONE_LEN,
 
+	/* The following attributes were added in send stream v2. */
+
+	BTRFS_SEND_A_FALLOCATE_MODE,
+
+	BTRFS_SEND_A_SETFLAGS_FLAGS,
+
+	BTRFS_SEND_A_UNENCODED_FILE_LEN,
+	BTRFS_SEND_A_UNENCODED_LEN,
+	BTRFS_SEND_A_UNENCODED_OFFSET,
+	BTRFS_SEND_A_COMPRESSION,
+	BTRFS_SEND_A_ENCRYPTION,
+
 	__BTRFS_SEND_A_MAX,
 };
 #define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1)
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 95da52955894..4f875f355e83 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -771,6 +771,19 @@ struct btrfs_ioctl_received_subvol_args {
  */
 #define BTRFS_SEND_FLAG_OMIT_END_CMD		0x4
 
+/*
+ * Use version 2 of the send stream, which adds new commands and supports larger
+ * writes.
+ */
+#define BTRFS_SEND_FLAG_STREAM_V2		0x8
+
+/*
+ * Send compressed data using the ENCODED_WRITE command instead of decompressing
+ * the data and sending it with the WRITE command. This requires
+ * BTRFS_SEND_FLAG_STREAM_V2.
+ */
+#define BTRFS_SEND_FLAG_COMPRESSED		0x10
+
 #define BTRFS_SEND_FLAG_MASK \
 	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
 	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 11/14] btrfs: send: write larger chunks when using stream v2
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (9 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 10/14] btrfs: add send stream v2 definitions Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-18 12:57   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 12/14] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2 Omar Sandoval
                   ` (12 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

The length field of the send stream TLV header is 16 bits. This means
that the maximum amount of data that can be sent for one write is 64k
minus one. However, encoded writes must be able to send the maximum
compressed extent (128k) in one command. To support this, send stream
version 2 encodes the DATA attribute differently: it has no length
field, and the length is implicitly up to the end of containing command
(which has a 32-bit length field). Although this is necessary for
encoded writes, normal writes can benefit from it, too.

For v2, let's bump up the send buffer to the maximum compressed extent
size plus 16k for the other metadata (144k total). Since this will most
likely be vmalloc'd (and always will be after the next commit), we round
it up to the next page since we might as well use the rest of the page
on systems with >16k pages.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/send.c | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 2ec07943f173..80736e2670eb 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -4908,14 +4908,27 @@ static inline u64 max_send_read_size(const struct send_ctx *sctx)
 
 static int put_data_header(struct send_ctx *sctx, u32 len)
 {
-	struct btrfs_tlv_header *hdr;
+	if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) {
+		/*
+		 * In v2, the data attribute header doesn't include a length; it
+		 * is implicitly to the end of the command.
+		 */
+		if (sctx->send_max_size - sctx->send_size < 2 + len)
+			return -EOVERFLOW;
+		put_unaligned_le16(BTRFS_SEND_A_DATA,
+				   sctx->send_buf + sctx->send_size);
+		sctx->send_size += 2;
+	} else {
+		struct btrfs_tlv_header *hdr;
 
-	if (sctx->send_max_size - sctx->send_size < sizeof(*hdr) + len)
-		return -EOVERFLOW;
-	hdr = (struct btrfs_tlv_header *)(sctx->send_buf + sctx->send_size);
-	put_unaligned_le16(BTRFS_SEND_A_DATA, &hdr->tlv_type);
-	put_unaligned_le16(len, &hdr->tlv_len);
-	sctx->send_size += sizeof(*hdr);
+		if (sctx->send_max_size - sctx->send_size < sizeof(*hdr) + len)
+			return -EOVERFLOW;
+		hdr = (struct btrfs_tlv_header *)(sctx->send_buf +
+						  sctx->send_size);
+		put_unaligned_le16(BTRFS_SEND_A_DATA, &hdr->tlv_type);
+		put_unaligned_le16(len, &hdr->tlv_len);
+		sctx->send_size += sizeof(*hdr);
+	}
 	return 0;
 }
 
@@ -7287,7 +7300,12 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 
 	sctx->clone_roots_cnt = arg->clone_sources_count;
 
-	sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
+	if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) {
+		sctx->send_max_size = ALIGN(SZ_16K + BTRFS_MAX_COMPRESSED,
+					    PAGE_SIZE);
+	} else {
+		sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
+	}
 	sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
 	if (!sctx->send_buf) {
 		ret = -ENOMEM;
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 12/14] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (10 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 11/14] btrfs: send: write larger chunks when using stream v2 Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-18 11:10   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes Omar Sandoval
                   ` (11 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

For encoded writes, we need the raw pages for reading compressed data
directly via a bio. So, replace kvmalloc() with vmap() so we have access
to the raw pages. 144k is large enough that it usually gets allocated
with vmalloc(), anyways.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/send.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 80736e2670eb..a000efe2658a 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -81,6 +81,7 @@ struct send_ctx {
 	char *send_buf;
 	u32 send_size;
 	u32 send_max_size;
+	struct page **send_buf_pages;
 	u64 total_send_size;
 	u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
 	u64 flags;	/* 'flags' member of btrfs_ioctl_send_args is u64 */
@@ -7223,6 +7224,7 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 	struct btrfs_root *clone_root;
 	struct send_ctx *sctx = NULL;
 	u32 i;
+	u32 send_buf_num_pages = 0;
 	u64 *clone_sources_tmp = NULL;
 	int clone_sources_to_rollback = 0;
 	size_t alloc_size;
@@ -7303,10 +7305,28 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 	if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) {
 		sctx->send_max_size = ALIGN(SZ_16K + BTRFS_MAX_COMPRESSED,
 					    PAGE_SIZE);
+		send_buf_num_pages = sctx->send_max_size >> PAGE_SHIFT;
+		sctx->send_buf_pages = kcalloc(send_buf_num_pages,
+					       sizeof(*sctx->send_buf_pages),
+					       GFP_KERNEL);
+		if (!sctx->send_buf_pages) {
+			send_buf_num_pages = 0;
+			ret = -ENOMEM;
+			goto out;
+		}
+		for (i = 0; i < send_buf_num_pages; i++) {
+			sctx->send_buf_pages[i] = alloc_page(GFP_KERNEL);
+			if (!sctx->send_buf_pages[i]) {
+				ret = -ENOMEM;
+				goto out;
+			}
+		}
+		sctx->send_buf = vmap(sctx->send_buf_pages, send_buf_num_pages,
+				      VM_MAP, PAGE_KERNEL);
 	} else {
 		sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
+		sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
 	}
-	sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
 	if (!sctx->send_buf) {
 		ret = -ENOMEM;
 		goto out;
@@ -7513,7 +7533,16 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 			fput(sctx->send_filp);
 
 		kvfree(sctx->clone_roots);
-		kvfree(sctx->send_buf);
+		if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) {
+			vunmap(sctx->send_buf);
+			for (i = 0; i < send_buf_num_pages; i++) {
+				if (sctx->send_buf_pages[i])
+					__free_page(sctx->send_buf_pages[i]);
+			}
+			kfree(sctx->send_buf_pages);
+		} else {
+			kvfree(sctx->send_buf);
+		}
 
 		name_cache_free(sctx);
 
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (11 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 12/14] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2 Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-18 11:59   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes Omar Sandoval
                   ` (10 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

Now that all of the pieces are in place, we can use the ENCODED_WRITE
command to send compressed extents when appropriate.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/ctree.h |   4 +
 fs/btrfs/inode.c |   6 +-
 fs/btrfs/send.c  | 230 +++++++++++++++++++++++++++++++++++++++++++----
 3 files changed, 220 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7753976bc3c7..caec0422a5c4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3223,6 +3223,10 @@ int btrfs_writepage_cow_fixup(struct page *page);
 void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
 					  struct page *page, u64 start,
 					  u64 end, bool uptodate);
+int btrfs_encoded_io_compression_from_extent(int compress_type);
+int btrfs_encoded_read_regular_fill_pages(struct inode *inode, u64 offset,
+					  u64 disk_io_size,
+					  struct page **pages);
 struct btrfs_ioctl_encoded_io_args;
 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
 			   struct btrfs_ioctl_encoded_io_args *encoded);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e751af96c198..6c40419eb2b1 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10502,7 +10502,7 @@ void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
 	}
 }
 
-static int btrfs_encoded_io_compression_from_extent(int compress_type)
+int btrfs_encoded_io_compression_from_extent(int compress_type)
 {
 	switch (compress_type) {
 	case BTRFS_COMPRESS_NONE:
@@ -10705,8 +10705,8 @@ static void btrfs_encoded_read_endio(struct bio *bio)
 	bio_put(bio);
 }
 
-static int btrfs_encoded_read_regular_fill_pages(struct inode *inode, u64 offset,
-						 u64 disk_io_size, struct page **pages)
+int btrfs_encoded_read_regular_fill_pages(struct inode *inode, u64 offset,
+					  u64 disk_io_size, struct page **pages)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_encoded_read_private priv = {
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index a000efe2658a..0ba8dc3a9f56 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -595,6 +595,7 @@ static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
 		return tlv_put(sctx, attr, &__tmp, sizeof(__tmp));	\
 	}
 
+TLV_PUT_DEFINE_INT(32)
 TLV_PUT_DEFINE_INT(64)
 
 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
@@ -5203,16 +5204,211 @@ static int send_hole(struct send_ctx *sctx, u64 end)
 	return ret;
 }
 
-static int send_extent_data(struct send_ctx *sctx,
-			    const u64 offset,
-			    const u64 len)
+static int send_encoded_inline_extent(struct send_ctx *sctx,
+				      struct btrfs_path *path, u64 offset,
+				      u64 len)
 {
+	struct btrfs_root *root = sctx->send_root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct inode *inode;
+	struct fs_path *p;
+	struct extent_buffer *leaf = path->nodes[0];
+	struct btrfs_key key;
+	struct btrfs_file_extent_item *ei;
+	u64 ram_bytes;
+	size_t inline_size;
+	int ret;
+
+	inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	p = fs_path_alloc();
+	if (!p) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = begin_cmd(sctx, BTRFS_SEND_C_ENCODED_WRITE);
+	if (ret < 0)
+		goto out;
+
+	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
+	if (ret < 0)
+		goto out;
+
+	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+	ei = btrfs_item_ptr(leaf, path->slots[0],
+			    struct btrfs_file_extent_item);
+	ram_bytes = btrfs_file_extent_ram_bytes(leaf, ei);
+	inline_size = btrfs_file_extent_inline_item_len(leaf,
+						btrfs_item_nr(path->slots[0]));
+
+	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN,
+		    min(key.offset + ram_bytes - offset, len));
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN, ram_bytes);
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET, offset - key.offset);
+	ret = btrfs_encoded_io_compression_from_extent(
+				btrfs_file_extent_compression(leaf, ei));
+	if (ret < 0)
+		goto out;
+	TLV_PUT_U32(sctx, BTRFS_SEND_A_COMPRESSION, ret);
+	TLV_PUT_U32(sctx, BTRFS_SEND_A_ENCRYPTION, 0);
+
+	ret = put_data_header(sctx, inline_size);
+	if (ret < 0)
+		goto out;
+	read_extent_buffer(leaf, sctx->send_buf + sctx->send_size,
+			   btrfs_file_extent_inline_start(ei), inline_size);
+	sctx->send_size += inline_size;
+
+	ret = send_cmd(sctx);
+
+tlv_put_failure:
+out:
+	fs_path_free(p);
+	iput(inode);
+	return ret;
+}
+
+static int send_encoded_extent(struct send_ctx *sctx, struct btrfs_path *path,
+			       u64 offset, u64 len)
+{
+	struct btrfs_root *root = sctx->send_root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct inode *inode;
+	struct fs_path *p;
+	struct extent_buffer *leaf = path->nodes[0];
+	struct btrfs_key key;
+	struct btrfs_file_extent_item *ei;
+	u64 block_start;
+	u64 block_len;
+	u32 data_offset;
+	struct btrfs_cmd_header *hdr;
+	u32 crc;
+	int ret;
+
+	inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	p = fs_path_alloc();
+	if (!p) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = begin_cmd(sctx, BTRFS_SEND_C_ENCODED_WRITE);
+	if (ret < 0)
+		goto out;
+
+	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
+	if (ret < 0)
+		goto out;
+
+	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+	ei = btrfs_item_ptr(leaf, path->slots[0],
+			    struct btrfs_file_extent_item);
+	block_start = btrfs_file_extent_disk_bytenr(leaf, ei);
+	block_len = btrfs_file_extent_disk_num_bytes(leaf, ei);
+
+	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN,
+		    min(key.offset + btrfs_file_extent_num_bytes(leaf, ei) - offset,
+			len));
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN,
+		    btrfs_file_extent_ram_bytes(leaf, ei));
+	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET,
+		    offset - key.offset + btrfs_file_extent_offset(leaf, ei));
+	ret = btrfs_encoded_io_compression_from_extent(
+				btrfs_file_extent_compression(leaf, ei));
+	if (ret < 0)
+		goto out;
+	TLV_PUT_U32(sctx, BTRFS_SEND_A_COMPRESSION, ret);
+	TLV_PUT_U32(sctx, BTRFS_SEND_A_ENCRYPTION, 0);
+
+	ret = put_data_header(sctx, block_len);
+	if (ret < 0)
+		goto out;
+
+	data_offset = ALIGN(sctx->send_size, PAGE_SIZE);
+	if (data_offset > sctx->send_max_size ||
+	    sctx->send_max_size - data_offset < block_len) {
+		ret = -EOVERFLOW;
+		goto out;
+	}
+
+	ret = btrfs_encoded_read_regular_fill_pages(inode, block_start,
+						    block_len,
+						    sctx->send_buf_pages +
+						    (data_offset >> PAGE_SHIFT));
+	if (ret)
+		goto out;
+
+	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
+	hdr->len = cpu_to_le32(sctx->send_size + block_len - sizeof(*hdr));
+	hdr->crc = 0;
+	crc = btrfs_crc32c(0, sctx->send_buf, sctx->send_size);
+	crc = btrfs_crc32c(crc, sctx->send_buf + data_offset, block_len);
+	hdr->crc = cpu_to_le32(crc);
+
+	ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
+			&sctx->send_off);
+	if (!ret) {
+		ret = write_buf(sctx->send_filp, sctx->send_buf + data_offset,
+				block_len, &sctx->send_off);
+	}
+	sctx->total_send_size += sctx->send_size + block_len;
+	sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] +=
+		sctx->send_size + block_len;
+	sctx->send_size = 0;
+
+tlv_put_failure:
+out:
+	fs_path_free(p);
+	iput(inode);
+	return ret;
+}
+
+static int send_extent_data(struct send_ctx *sctx, struct btrfs_path *path,
+			    const u64 offset, const u64 len)
+{
+	struct extent_buffer *leaf = path->nodes[0];
+	struct btrfs_file_extent_item *ei;
 	u64 read_size = max_send_read_size(sctx);
 	u64 sent = 0;
 
 	if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
 		return send_update_extent(sctx, offset, len);
 
+	ei = btrfs_item_ptr(leaf, path->slots[0],
+			    struct btrfs_file_extent_item);
+	if ((sctx->flags & BTRFS_SEND_FLAG_COMPRESSED) &&
+	    btrfs_file_extent_compression(leaf, ei) != BTRFS_COMPRESS_NONE) {
+		bool is_inline = (btrfs_file_extent_type(leaf, ei) ==
+				  BTRFS_FILE_EXTENT_INLINE);
+
+		/*
+		 * Send the compressed extent unless the compressed data is
+		 * larger than the decompressed data. This can happen if we're
+		 * not sending the entire extent, either because it has been
+		 * partially overwritten/truncated or because this is a part of
+		 * the extent that we couldn't clone in clone_range().
+		 */
+		if (is_inline &&
+		    btrfs_file_extent_inline_item_len(leaf,
+					btrfs_item_nr(path->slots[0])) <= len) {
+			return send_encoded_inline_extent(sctx, path, offset,
+							  len);
+		} else if (!is_inline &&
+			   btrfs_file_extent_disk_num_bytes(leaf, ei) <= len) {
+			return send_encoded_extent(sctx, path, offset, len);
+		}
+	}
+
 	while (sent < len) {
 		u64 size = min(len - sent, read_size);
 		int ret;
@@ -5283,12 +5479,9 @@ static int send_capabilities(struct send_ctx *sctx)
 	return ret;
 }
 
-static int clone_range(struct send_ctx *sctx,
-		       struct clone_root *clone_root,
-		       const u64 disk_byte,
-		       u64 data_offset,
-		       u64 offset,
-		       u64 len)
+static int clone_range(struct send_ctx *sctx, struct btrfs_path *dst_path,
+		       struct clone_root *clone_root, const u64 disk_byte,
+		       u64 data_offset, u64 offset, u64 len)
 {
 	struct btrfs_path *path;
 	struct btrfs_key key;
@@ -5312,7 +5505,7 @@ static int clone_range(struct send_ctx *sctx,
 	 */
 	if (clone_root->offset == 0 &&
 	    len == sctx->send_root->fs_info->sectorsize)
-		return send_extent_data(sctx, offset, len);
+		return send_extent_data(sctx, dst_path, offset, len);
 
 	path = alloc_path_for_send();
 	if (!path)
@@ -5409,7 +5602,8 @@ static int clone_range(struct send_ctx *sctx,
 
 			if (hole_len > len)
 				hole_len = len;
-			ret = send_extent_data(sctx, offset, hole_len);
+			ret = send_extent_data(sctx, dst_path, offset,
+					       hole_len);
 			if (ret < 0)
 				goto out;
 
@@ -5482,14 +5676,16 @@ static int clone_range(struct send_ctx *sctx,
 					if (ret < 0)
 						goto out;
 				}
-				ret = send_extent_data(sctx, offset + slen,
+				ret = send_extent_data(sctx, dst_path,
+						       offset + slen,
 						       clone_len - slen);
 			} else {
 				ret = send_clone(sctx, offset, clone_len,
 						 clone_root);
 			}
 		} else {
-			ret = send_extent_data(sctx, offset, clone_len);
+			ret = send_extent_data(sctx, dst_path, offset,
+					       clone_len);
 		}
 
 		if (ret < 0)
@@ -5521,7 +5717,7 @@ static int clone_range(struct send_ctx *sctx,
 	}
 
 	if (len > 0)
-		ret = send_extent_data(sctx, offset, len);
+		ret = send_extent_data(sctx, dst_path, offset, len);
 	else
 		ret = 0;
 out:
@@ -5552,10 +5748,10 @@ static int send_write_or_clone(struct send_ctx *sctx,
 				    struct btrfs_file_extent_item);
 		disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei);
 		data_offset = btrfs_file_extent_offset(path->nodes[0], ei);
-		ret = clone_range(sctx, clone_root, disk_byte, data_offset,
-				  offset, end - offset);
+		ret = clone_range(sctx, path, clone_root, disk_byte,
+				  data_offset, offset, end - offset);
 	} else {
-		ret = send_extent_data(sctx, offset, end - offset);
+		ret = send_extent_data(sctx, path, offset, end - offset);
 	}
 	sctx->cur_inode_next_write_offset = end;
 	return ret;
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (12 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-18 12:44   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len Omar Sandoval
                   ` (9 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Omar Sandoval <osandov@fb.com>

Now that the new support is implemented, allow the ioctl to accept the
flags and update the version in sysfs.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/send.c            | 10 +++++++++-
 fs/btrfs/send.h            |  2 +-
 include/uapi/linux/btrfs.h |  4 +++-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 0ba8dc3a9f56..90ca915fed78 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -671,7 +671,10 @@ static int send_header(struct send_ctx *sctx)
 	struct btrfs_stream_header hdr;
 
 	strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
-	hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
+	if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2)
+		hdr.version = cpu_to_le32(2);
+	else
+		hdr.version = cpu_to_le32(1);
 
 	return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
 					&sctx->send_off);
@@ -7466,6 +7469,11 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
 		ret = -EINVAL;
 		goto out;
 	}
+	if ((arg->flags & BTRFS_SEND_FLAG_COMPRESSED) &&
+	    !(arg->flags & BTRFS_SEND_FLAG_STREAM_V2)) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL);
 	if (!sctx) {
diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
index 9f4f7b96b1eb..9c83e14a43b2 100644
--- a/fs/btrfs/send.h
+++ b/fs/btrfs/send.h
@@ -10,7 +10,7 @@
 #include "ctree.h"
 
 #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
-#define BTRFS_SEND_STREAM_VERSION 1
+#define BTRFS_SEND_STREAM_VERSION 2
 
 /*
  * In send stream v1, no command is larger than 64k. In send stream v2, no limit
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 4f875f355e83..5c13e407982f 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -787,7 +787,9 @@ struct btrfs_ioctl_received_subvol_args {
 #define BTRFS_SEND_FLAG_MASK \
 	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
 	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \
-	 BTRFS_SEND_FLAG_OMIT_END_CMD)
+	 BTRFS_SEND_FLAG_OMIT_END_CMD | \
+	 BTRFS_SEND_FLAG_STREAM_V2 | \
+	 BTRFS_SEND_FLAG_COMPRESSED)
 
 struct btrfs_ioctl_send_args {
 	__s64 send_fd;			/* in */
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (13 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-20 13:49   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf Omar Sandoval
                   ` (8 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <borisb@fb.com>

An encoded extent can be up to 128K in length, which exceeds the largest
value expressible by the current send stream format's 16 bit tlv_len
field. Since encoded writes cannot be split into multiple writes by
btrfs send, the send stream format must change to accommodate encoded
writes.

Supporting this changed format requires retooling how we store the
commands we have processed. Since we can no longer use btrfs_tlv_header
to describe every attribute, we define a new struct btrfs_send_attribute
which has a 32 bit length field, and use that to store the attribute
information needed for receive processing. This is transparent to users
of the various TLV_GET macros.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 common/send-stream.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/common/send-stream.c b/common/send-stream.c
index a0c52f79..cd5aa311 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -24,13 +24,23 @@
 #include "crypto/crc32c.h"
 #include "common/utils.h"
 
+struct btrfs_send_attribute {
+	u16 tlv_type;
+	/*
+	 * Note: in btrfs_tlv_header, this is __le16, but we need 32 bits for
+	 * attributes with file data as of version 2 of the send stream format
+	 */
+	u32 tlv_len;
+	char *data;
+};
+
 struct btrfs_send_stream {
 	char read_buf[BTRFS_SEND_BUF_SIZE];
 	int fd;
 
 	int cmd;
 	struct btrfs_cmd_header *cmd_hdr;
-	struct btrfs_tlv_header *cmd_attrs[BTRFS_SEND_A_MAX + 1];
+	struct btrfs_send_attribute cmd_attrs[BTRFS_SEND_A_MAX + 1];
 	u32 version;
 
 	/*
@@ -152,6 +162,7 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 		struct btrfs_tlv_header *tlv_hdr;
 		u16 tlv_type;
 		u16 tlv_len;
+		struct btrfs_send_attribute *send_attr;
 
 		tlv_hdr = (struct btrfs_tlv_header *)data;
 		tlv_type = le16_to_cpu(tlv_hdr->tlv_type);
@@ -164,10 +175,15 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 			goto out;
 		}
 
-		sctx->cmd_attrs[tlv_type] = tlv_hdr;
+		send_attr = &sctx->cmd_attrs[tlv_type];
+		send_attr->tlv_type = tlv_type;
+		send_attr->tlv_len = tlv_len;
+		pos += sizeof(*tlv_hdr);
+		data += sizeof(*tlv_hdr);
 
-		data += sizeof(*tlv_hdr) + tlv_len;
-		pos += sizeof(*tlv_hdr) + tlv_len;
+		send_attr->data = data;
+		pos += send_attr->tlv_len;
+		data += send_attr->tlv_len;
 	}
 
 	sctx->cmd = cmd;
@@ -180,7 +196,7 @@ out:
 static int tlv_get(struct btrfs_send_stream *sctx, int attr, void **data, int *len)
 {
 	int ret;
-	struct btrfs_tlv_header *hdr;
+	struct btrfs_send_attribute *send_attr;
 
 	if (attr <= 0 || attr > BTRFS_SEND_A_MAX) {
 		error("invalid attribute requested, attr = %d", attr);
@@ -188,15 +204,15 @@ static int tlv_get(struct btrfs_send_stream *sctx, int attr, void **data, int *l
 		goto out;
 	}
 
-	hdr = sctx->cmd_attrs[attr];
-	if (!hdr) {
+	send_attr = &sctx->cmd_attrs[attr];
+	if (!send_attr->data) {
 		error("attribute %d requested but not present", attr);
 		ret = -ENOENT;
 		goto out;
 	}
 
-	*len = le16_to_cpu(hdr->tlv_len);
-	*data = hdr + 1;
+	*len = send_attr->tlv_len;
+	*data = send_attr->data;
 
 	ret = 0;
 
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (14 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-20 14:09   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 03/10] btrfs-progs: receive: support v2 send stream DATA tlv format Omar Sandoval
                   ` (7 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

In send stream v2, write commands can now be an arbitrary size. For that
reason, we can no longer allocate a fixed array in sctx for read_cmd.
Instead, read_cmd dynamically allocates sctx->read_buf. To avoid
needless reallocations, we reuse read_buf between read_cmd calls by also
keeping track of the size of the allocated buffer in sctx->read_buf_sz.

We do the first allocation of the old default size at the start of
processing the stream, and we only reallocate if we encounter a command
that needs a larger buffer.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 common/send-stream.c | 55 ++++++++++++++++++++++++++++----------------
 send.h               |  2 +-
 2 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/common/send-stream.c b/common/send-stream.c
index cd5aa311..3d3585c3 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -35,11 +35,11 @@ struct btrfs_send_attribute {
 };
 
 struct btrfs_send_stream {
-	char read_buf[BTRFS_SEND_BUF_SIZE];
+	char *read_buf;
+	size_t read_buf_sz;
 	int fd;
 
 	int cmd;
-	struct btrfs_cmd_header *cmd_hdr;
 	struct btrfs_send_attribute cmd_attrs[BTRFS_SEND_A_MAX + 1];
 	u32 version;
 
@@ -111,11 +111,12 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 	u32 pos;
 	u32 crc;
 	u32 crc2;
+	struct btrfs_cmd_header *cmd_hdr;
+	size_t buf_len;
 
 	memset(sctx->cmd_attrs, 0, sizeof(sctx->cmd_attrs));
 
-	ASSERT(sizeof(*sctx->cmd_hdr) <= sizeof(sctx->read_buf));
-	ret = read_buf(sctx, sctx->read_buf, sizeof(*sctx->cmd_hdr));
+	ret = read_buf(sctx, sctx->read_buf, sizeof(*cmd_hdr));
 	if (ret < 0)
 		goto out;
 	if (ret) {
@@ -124,18 +125,22 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 		goto out;
 	}
 
-	sctx->cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
-	cmd = le16_to_cpu(sctx->cmd_hdr->cmd);
-	cmd_len = le32_to_cpu(sctx->cmd_hdr->len);
-
-	if (cmd_len + sizeof(*sctx->cmd_hdr) >= sizeof(sctx->read_buf)) {
-		ret = -EINVAL;
-		error("command length %u too big for buffer %zu",
-				cmd_len, sizeof(sctx->read_buf));
-		goto out;
+	cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
+	cmd_len = le32_to_cpu(cmd_hdr->len);
+	cmd = le16_to_cpu(cmd_hdr->cmd);
+	buf_len = sizeof(*cmd_hdr) + cmd_len;
+	if (sctx->read_buf_sz < buf_len) {
+		sctx->read_buf = realloc(sctx->read_buf, buf_len);
+		if (!sctx->read_buf) {
+			ret = -ENOMEM;
+			error("failed to reallocate read buffer for cmd");
+			goto out;
+		}
+		sctx->read_buf_sz = buf_len;
+		/* We need to reset cmd_hdr after realloc of sctx->read_buf */
+		cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
 	}
-
-	data = sctx->read_buf + sizeof(*sctx->cmd_hdr);
+	data = sctx->read_buf + sizeof(*cmd_hdr);
 	ret = read_buf(sctx, data, cmd_len);
 	if (ret < 0)
 		goto out;
@@ -145,11 +150,12 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 		goto out;
 	}
 
-	crc = le32_to_cpu(sctx->cmd_hdr->crc);
-	sctx->cmd_hdr->crc = 0;
+	crc = le32_to_cpu(cmd_hdr->crc);
+	/* in send, crc is computed with header crc = 0, replicate that */
+	cmd_hdr->crc = 0;
 
 	crc2 = crc32c(0, (unsigned char*)sctx->read_buf,
-			sizeof(*sctx->cmd_hdr) + cmd_len);
+			sizeof(*cmd_hdr) + cmd_len);
 
 	if (crc != crc2) {
 		ret = -EINVAL;
@@ -524,19 +530,28 @@ int btrfs_read_and_process_send_stream(int fd,
 		goto out;
 	}
 
+	sctx.read_buf = malloc(BTRFS_SEND_BUF_SIZE_V1);
+	if (!sctx.read_buf) {
+		ret = -ENOMEM;
+		error("unable to allocate send stream read buffer");
+		goto out;
+	}
+	sctx.read_buf_sz = BTRFS_SEND_BUF_SIZE_V1;
+
 	while (1) {
 		ret = read_and_process_cmd(&sctx);
 		if (ret < 0) {
 			last_err = ret;
 			errors++;
 			if (max_errors > 0 && errors >= max_errors)
-				goto out;
+				break;
 		} else if (ret > 0) {
 			if (!honor_end_cmd)
 				ret = 0;
-			goto out;
+			break;
 		}
 	}
+	free(sctx.read_buf);
 
 out:
 	if (last_err && !ret)
diff --git a/send.h b/send.h
index 8dd865ec..228928a0 100644
--- a/send.h
+++ b/send.h
@@ -33,7 +33,7 @@ extern "C" {
 #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
 #define BTRFS_SEND_STREAM_VERSION 1
 
-#define BTRFS_SEND_BUF_SIZE SZ_64K
+#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
 #define BTRFS_SEND_READ_SIZE (1024 * 48)
 
 enum btrfs_tlv_type {
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 03/10] btrfs-progs: receive: support v2 send stream DATA tlv format
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (15 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-20 14:36   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 04/10] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h Omar Sandoval
                   ` (6 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <borisb@fb.com>

The new format privileges the BTRFS_SEND_A_DATA attribute by
guaranteeing it will always be the last attribute in any command that
needs it, and by implicitly encoding the data length as the difference
between the total command length in the command header and the sizes of
the rest of the attributes (and of course the tlv_type identifying the
DATA attribute). To parse the new stream, we must read the tlv_type and
if it is not DATA, we proceed normally, but if it is DATA, we don't
parse a tlv_len but simply compute the length.

In addition, we add some bounds checking when parsing each chunk of
data, as well as for the tlv_len itself.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 common/send-stream.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/common/send-stream.c b/common/send-stream.c
index 3d3585c3..4d819185 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -165,28 +165,44 @@ static int read_cmd(struct btrfs_send_stream *sctx)
 
 	pos = 0;
 	while (pos < cmd_len) {
-		struct btrfs_tlv_header *tlv_hdr;
 		u16 tlv_type;
-		u16 tlv_len;
 		struct btrfs_send_attribute *send_attr;
 
-		tlv_hdr = (struct btrfs_tlv_header *)data;
-		tlv_type = le16_to_cpu(tlv_hdr->tlv_type);
-		tlv_len = le16_to_cpu(tlv_hdr->tlv_len);
+		if (cmd_len - pos < sizeof(__le16)) {
+			error("send stream is truncated");
+			ret = -EINVAL;
+			goto out;
+		}
+		tlv_type = le16_to_cpu(*(__le16 *)data);
 
 		if (tlv_type == 0 || tlv_type > BTRFS_SEND_A_MAX) {
-			error("invalid tlv in cmd tlv_type = %hu, tlv_len = %hu",
-					tlv_type, tlv_len);
+			error("invalid tlv in cmd tlv_type = %hu", tlv_type);
 			ret = -EINVAL;
 			goto out;
 		}
 
 		send_attr = &sctx->cmd_attrs[tlv_type];
 		send_attr->tlv_type = tlv_type;
-		send_attr->tlv_len = tlv_len;
-		pos += sizeof(*tlv_hdr);
-		data += sizeof(*tlv_hdr);
 
+		pos += sizeof(tlv_type);
+		data += sizeof(tlv_type);
+		if (sctx->version == 2 && tlv_type == BTRFS_SEND_A_DATA) {
+			send_attr->tlv_len = cmd_len - pos;
+		} else {
+			if (cmd_len - pos < sizeof(__le16)) {
+				error("send stream is truncated");
+				ret = -EINVAL;
+				goto out;
+			}
+			send_attr->tlv_len = le16_to_cpu(*(__le16 *)data);
+			pos += sizeof(__le16);
+			data += sizeof(__le16);
+		}
+		if (cmd_len - pos < send_attr->tlv_len) {
+			error("send stream is truncated");
+			ret = -EINVAL;
+			goto out;
+		}
 		send_attr->data = data;
 		pos += send_attr->tlv_len;
 		data += send_attr->tlv_len;
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 04/10] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (16 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 03/10] btrfs-progs: receive: support v2 send stream DATA tlv format Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-20 14:38   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands Omar Sandoval
                   ` (5 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

Send stream v2 adds three commands and several attributes associated to
those commands. Before we implement processing them, add all the
commands and attributes. This avoids leaving the enums in an
intermediate state that doesn't correspond to any version of send
stream.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 send.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/send.h b/send.h
index 228928a0..3c47e0c7 100644
--- a/send.h
+++ b/send.h
@@ -98,6 +98,11 @@ enum btrfs_send_cmd {
 
 	BTRFS_SEND_C_END,
 	BTRFS_SEND_C_UPDATE_EXTENT,
+
+	BTRFS_SEND_C_FALLOCATE,
+	BTRFS_SEND_C_SETFLAGS,
+	BTRFS_SEND_C_ENCODED_WRITE,
+
 	__BTRFS_SEND_C_MAX,
 };
 #define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
@@ -136,6 +141,16 @@ enum {
 	BTRFS_SEND_A_CLONE_OFFSET,
 	BTRFS_SEND_A_CLONE_LEN,
 
+	BTRFS_SEND_A_FALLOCATE_MODE,
+
+	BTRFS_SEND_A_SETFLAGS_FLAGS,
+
+	BTRFS_SEND_A_UNENCODED_FILE_LEN,
+	BTRFS_SEND_A_UNENCODED_LEN,
+	BTRFS_SEND_A_UNENCODED_OFFSET,
+	BTRFS_SEND_A_COMPRESSION,
+	BTRFS_SEND_A_ENCRYPTION,
+
 	__BTRFS_SEND_A_MAX,
 };
 #define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1)
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (17 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 04/10] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-21 13:33   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write Omar Sandoval
                   ` (4 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <borisb@fb.com>

Add a new btrfs_send_op and support for both dumping and proper receive
processing which does actual encoded writes.

Encoded writes are only allowed on a file descriptor opened with an
extra flag that allows encoded writes, so we also add support for this
flag when opening or reusing a file for writing.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 cmds/receive-dump.c  |  16 +++++-
 cmds/receive.c       |  47 +++++++++++++++
 common/send-stream.c |  22 ++++++++
 common/send-stream.h |   4 ++
 ioctl.h              | 132 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 220 insertions(+), 1 deletion(-)

diff --git a/cmds/receive-dump.c b/cmds/receive-dump.c
index 648d9314..20ec2b70 100644
--- a/cmds/receive-dump.c
+++ b/cmds/receive-dump.c
@@ -316,6 +316,19 @@ static int print_update_extent(const char *path, u64 offset, u64 len,
 			  offset, len);
 }
 
+static int print_encoded_write(const char *path, const void *data, u64 offset,
+			       u64 len, u64 unencoded_file_len,
+			       u64 unencoded_len, u64 unencoded_offset,
+			       u32 compression, u32 encryption, void *user)
+{
+	return PRINT_DUMP(user, path, "encoded_write",
+			  "offset=%llu len=%llu, unencoded_file_len=%llu, "
+			  "unencoded_len=%llu, unencoded_offset=%llu, "
+			  "compression=%u, encryption=%u",
+			  offset, len, unencoded_file_len, unencoded_len,
+			  unencoded_offset, compression, encryption);
+}
+
 struct btrfs_send_ops btrfs_print_send_ops = {
 	.subvol = print_subvol,
 	.snapshot = print_snapshot,
@@ -337,5 +350,6 @@ struct btrfs_send_ops btrfs_print_send_ops = {
 	.chmod = print_chmod,
 	.chown = print_chown,
 	.utimes = print_utimes,
-	.update_extent = print_update_extent
+	.update_extent = print_update_extent,
+	.encoded_write = print_encoded_write,
 };
diff --git a/cmds/receive.c b/cmds/receive.c
index 4dd01fd3..b43c298f 100644
--- a/cmds/receive.c
+++ b/cmds/receive.c
@@ -29,12 +29,14 @@
 #include <assert.h>
 #include <getopt.h>
 #include <limits.h>
+#include <errno.h>
 
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/uio.h>
 #include <sys/xattr.h>
 #include <uuid/uuid.h>
 
@@ -51,6 +53,7 @@
 #include "cmds/receive-dump.h"
 #include "common/help.h"
 #include "common/path-utils.h"
+#include "stubs.h"
 
 struct btrfs_receive
 {
@@ -986,6 +989,49 @@ static int process_update_extent(const char *path, u64 offset, u64 len,
 	return 0;
 }
 
+static int process_encoded_write(const char *path, const void *data, u64 offset,
+	u64 len, u64 unencoded_file_len, u64 unencoded_len,
+	u64 unencoded_offset, u32 compression, u32 encryption, void *user)
+{
+	int ret;
+	struct btrfs_receive *rctx = user;
+	char full_path[PATH_MAX];
+	struct iovec iov = { (char *)data, len };
+	struct btrfs_ioctl_encoded_io_args encoded = {
+		.iov = &iov,
+		.iovcnt = 1,
+		.offset = offset,
+		.len = unencoded_file_len,
+		.unencoded_len = unencoded_len,
+		.unencoded_offset = unencoded_offset,
+		.compression = compression,
+		.encryption = encryption,
+	};
+
+	if (encryption) {
+		error("encoded_write: encryption not supported");
+		return -EOPNOTSUPP;
+	}
+
+	ret = path_cat_out(full_path, rctx->full_subvol_path, path);
+	if (ret < 0) {
+		error("encoded_write: path invalid: %s", path);
+		return ret;
+	}
+
+	ret = open_inode_for_write(rctx, full_path);
+	if (ret < 0)
+		return ret;
+
+	ret = ioctl(rctx->write_fd, BTRFS_IOC_ENCODED_WRITE, &encoded);
+	if (ret < 0) {
+		ret = -errno;
+		error("encoded_write: writing to %s failed: %m", path);
+		return ret;
+	}
+	return 0;
+}
+
 static struct btrfs_send_ops send_ops = {
 	.subvol = process_subvol,
 	.snapshot = process_snapshot,
@@ -1008,6 +1054,7 @@ static struct btrfs_send_ops send_ops = {
 	.chown = process_chown,
 	.utimes = process_utimes,
 	.update_extent = process_update_extent,
+	.encoded_write = process_encoded_write,
 };
 
 static int do_receive(struct btrfs_receive *rctx, const char *tomnt,
diff --git a/common/send-stream.c b/common/send-stream.c
index 4d819185..044e101b 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -354,6 +354,8 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 	struct timespec mt;
 	u8 uuid[BTRFS_UUID_SIZE];
 	u8 clone_uuid[BTRFS_UUID_SIZE];
+	u32 compression;
+	u32 encryption;
 	u64 tmp;
 	u64 tmp2;
 	u64 ctransid;
@@ -362,6 +364,9 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 	u64 dev;
 	u64 clone_offset;
 	u64 offset;
+	u64 unencoded_file_len;
+	u64 unencoded_len;
+	u64 unencoded_offset;
 	int len;
 	int xattr_len;
 
@@ -436,6 +441,23 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 		TLV_GET(sctx, BTRFS_SEND_A_DATA, &data, &len);
 		ret = sctx->ops->write(path, data, offset, len, sctx->user);
 		break;
+	case BTRFS_SEND_C_ENCODED_WRITE:
+		TLV_GET_STRING(sctx, BTRFS_SEND_A_PATH, &path);
+		TLV_GET_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, &offset);
+		TLV_GET_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN,
+			    &unencoded_file_len);
+		TLV_GET_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN, &unencoded_len);
+		TLV_GET_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET,
+			    &unencoded_offset);
+		TLV_GET_U32(sctx, BTRFS_SEND_A_COMPRESSION, &compression);
+		TLV_GET_U32(sctx, BTRFS_SEND_A_ENCRYPTION, &encryption);
+		TLV_GET(sctx, BTRFS_SEND_A_DATA, &data, &len);
+		ret = sctx->ops->encoded_write(path, data, offset, len,
+					       unencoded_file_len,
+					       unencoded_len, unencoded_offset,
+					       compression, encryption,
+					       sctx->user);
+		break;
 	case BTRFS_SEND_C_CLONE:
 		TLV_GET_STRING(sctx, BTRFS_SEND_A_PATH, &path);
 		TLV_GET_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, &offset);
diff --git a/common/send-stream.h b/common/send-stream.h
index 39901f86..607bc007 100644
--- a/common/send-stream.h
+++ b/common/send-stream.h
@@ -66,6 +66,10 @@ struct btrfs_send_ops {
 		      struct timespec *mt, struct timespec *ct,
 		      void *user);
 	int (*update_extent)(const char *path, u64 offset, u64 len, void *user);
+	int (*encoded_write)(const char *path, const void *data, u64 offset,
+			     u64 len, u64 unencoded_file_len, u64 unencoded_len,
+			     u64 unencoded_offset, u32 compression,
+			     u32 encryption, void *user);
 };
 
 int btrfs_read_and_process_send_stream(int fd,
diff --git a/ioctl.h b/ioctl.h
index 5ce47c83..90e283c8 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -775,6 +775,134 @@ struct btrfs_ioctl_get_subvol_rootref_args {
 };
 BUILD_ASSERT(sizeof(struct btrfs_ioctl_get_subvol_rootref_args) == 4096);
 
+/*
+ * Data and metadata for an encoded read or write.
+ *
+ * Encoded I/O bypasses any encoding automatically done by the filesystem (e.g.,
+ * compression). This can be used to read the compressed contents of a file or
+ * write pre-compressed data directly to a file.
+ *
+ * BTRFS_IOC_ENCODED_READ and BTRFS_IOC_ENCODED_WRITE are essentially
+ * preadv/pwritev with additional metadata about how the data is encoded and the
+ * size of the unencoded data.
+ *
+ * BTRFS_IOC_ENCODED_READ fills the given iovecs with the encoded data, fills
+ * the metadata fields, and returns the size of the encoded data. It reads one
+ * extent per call. It can also read data which is not encoded.
+ *
+ * BTRFS_IOC_ENCODED_WRITE uses the metadata fields, writes the encoded data
+ * from the iovecs, and returns the size of the encoded data. Note that the
+ * encoded data is not validated when it is written; if it is not valid (e.g.,
+ * it cannot be decompressed), then a subsequent read may return an error.
+ *
+ * Since the filesystem page cache contains decoded data, encoded I/O bypasses
+ * the page cache. Encoded I/O requires CAP_SYS_ADMIN.
+ */
+struct btrfs_ioctl_encoded_io_args {
+	/* Input parameters for both reads and writes. */
+
+	/*
+	 * iovecs containing encoded data.
+	 *
+	 * For reads, if the size of the encoded data is larger than the sum of
+	 * iov[n].iov_len for 0 <= n < iovcnt, then the ioctl fails with
+	 * ENOBUFS.
+	 *
+	 * For writes, the size of the encoded data is the sum of iov[n].iov_len
+	 * for 0 <= n < iovcnt. This must be less than 128 KiB (this limit may
+	 * increase in the future). This must also be less than or equal to
+	 * unencoded_len.
+	 */
+	const struct iovec *iov;
+	/* Number of iovecs. */
+	unsigned long iovcnt;
+	/*
+	 * Offset in file.
+	 *
+	 * For writes, must be aligned to the sector size of the filesystem.
+	 */
+	__s64 offset;
+	/* Currently must be zero. */
+	__u64 flags;
+
+	/*
+	 * For reads, the following members are filled in with the metadata for
+	 * the encoded data.
+	 * For writes, the following members must be set to the metadata for the
+	 * encoded data.
+	 */
+
+	/*
+	 * Length of the data in the file.
+	 *
+	 * Must be less than or equal to unencoded_len - unencoded_offset. For
+	 * writes, must be aligned to the sector size of the filesystem unless
+	 * the data ends at or beyond the current end of the file.
+	 */
+	__u64 len;
+	/*
+	 * Length of the unencoded (i.e., decrypted and decompressed) data.
+	 *
+	 * For writes, must be no more than 128 KiB (this limit may increase in
+	 * the future). If the unencoded data is actually longer than
+	 * unencoded_len, then it is truncated; if it is shorter, then it is
+	 * extended with zeroes.
+	 */
+	__u64 unencoded_len;
+	/*
+	 * Offset from the first byte of the unencoded data to the first byte of
+	 * logical data in the file.
+	 *
+	 * Must be less than unencoded_len.
+	 */
+	__u64 unencoded_offset;
+	/*
+	 * BTRFS_ENCODED_IO_COMPRESSION_* type.
+	 *
+	 * For writes, must not be BTRFS_ENCODED_IO_COMPRESSION_NONE.
+	 */
+	__u32 compression;
+	/* Currently always BTRFS_ENCODED_IO_ENCRYPTION_NONE. */
+	__u32 encryption;
+	/*
+	 * Reserved for future expansion.
+	 *
+	 * For reads, always returned as zero. Users should check for non-zero
+	 * bytes. If there are any, then the kernel has a newer version of this
+	 * structure with additional information that the user definition is
+	 * missing.
+	 *
+	 * For writes, must be zeroed.
+	 */
+	__u8 reserved[32];
+};
+
+/* Data is not compressed. */
+#define BTRFS_ENCODED_IO_COMPRESSION_NONE 0
+/* Data is compressed as a single zlib stream. */
+#define BTRFS_ENCODED_IO_COMPRESSION_ZLIB 1
+/*
+ * Data is compressed as a single zstd frame with the windowLog compression
+ * parameter set to no more than 17.
+ */
+#define BTRFS_ENCODED_IO_COMPRESSION_ZSTD 2
+/*
+ * Data is compressed page by page (using the page size indicated by the name of
+ * the constant) with LZO1X and wrapped in the format documented in
+ * fs/btrfs/lzo.c. For writes, the compression page size must match the
+ * filesystem page size.
+ */
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_4K 3
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_8K 4
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_16K 5
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_32K 6
+#define BTRFS_ENCODED_IO_COMPRESSION_LZO_64K 7
+#define BTRFS_ENCODED_IO_COMPRESSION_TYPES 8
+
+/* Data is not encrypted. */
+#define BTRFS_ENCODED_IO_ENCRYPTION_NONE 0
+#define BTRFS_ENCODED_IO_ENCRYPTION_TYPES 1
+
 /* Error codes as returned by the kernel */
 enum btrfs_err_code {
 	notused,
@@ -949,6 +1077,10 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code)
 				struct btrfs_ioctl_ino_lookup_user_args)
 #define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \
 				   struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_ENCODED_READ _IOR(BTRFS_IOCTL_MAGIC, 64, \
+				    struct btrfs_ioctl_encoded_io_args)
+#define BTRFS_IOC_ENCODED_WRITE _IOW(BTRFS_IOCTL_MAGIC, 64, \
+				     struct btrfs_ioctl_encoded_io_args)
 
 #ifdef __cplusplus
 }
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (18 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-21 13:55   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands Omar Sandoval
                   ` (3 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

An encoded_write can fail if the file system it is being applied to does
not support encoded writes or if it can't find enough contiguous space
to accommodate the encoded extent. In those cases, we can likely still
process an encoded_write by explicitly decoding the data and doing a
normal write.

Add the necessary fallback path for decoding data compressed with zlib,
lzo, or zstd. zlib and zstd have reusable decoding context data
structures which we cache in the receive context so that we don't have
to recreate them on every encoded_write.

Finally, add a command line flag for force-decompress which causes
receive to always use the fallback path rather than first attempting the
encoded write.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 Documentation/btrfs-receive.asciidoc |   4 +
 cmds/receive.c                       | 266 ++++++++++++++++++++++++++-
 2 files changed, 261 insertions(+), 9 deletions(-)

diff --git a/Documentation/btrfs-receive.asciidoc b/Documentation/btrfs-receive.asciidoc
index e4c4d2c0..354a71dc 100644
--- a/Documentation/btrfs-receive.asciidoc
+++ b/Documentation/btrfs-receive.asciidoc
@@ -60,6 +60,10 @@ By default the mountpoint is searched in '/proc/self/mounts'.
 If '/proc' is not accessible, eg. in a chroot environment, use this option to
 tell us where this filesystem is mounted.
 
+--force-decompress::
+if the stream contains compressed data (see '--compressed-data' in
+`btrfs-send`(8)), always decompress it instead of writing it with encoded I/O.
+
 --dump::
 dump the stream metadata, one line per operation
 +
diff --git a/cmds/receive.c b/cmds/receive.c
index b43c298f..2eebcfd1 100644
--- a/cmds/receive.c
+++ b/cmds/receive.c
@@ -40,6 +40,10 @@
 #include <sys/xattr.h>
 #include <uuid/uuid.h>
 
+#include <lzo/lzo1x.h>
+#include <zlib.h>
+#include <zstd.h>
+
 #include "kernel-shared/ctree.h"
 #include "ioctl.h"
 #include "cmds/commands.h"
@@ -79,6 +83,12 @@ struct btrfs_receive
 	struct subvol_uuid_search sus;
 
 	int honor_end_cmd;
+
+	int force_decompress;
+
+	/* Reuse stream objects for encoded_write decompression fallback */
+	ZSTD_DStream *zstd_dstream;
+	z_stream *zlib_stream;
 };
 
 static int finish_subvol(struct btrfs_receive *rctx)
@@ -989,9 +999,222 @@ static int process_update_extent(const char *path, u64 offset, u64 len,
 	return 0;
 }
 
+static int decompress_zlib(struct btrfs_receive *rctx, const char *encoded_data,
+			   u64 encoded_len, char *unencoded_data,
+			   u64 unencoded_len)
+{
+	bool init = false;
+	int ret;
+
+	if (!rctx->zlib_stream) {
+		init = true;
+		rctx->zlib_stream = malloc(sizeof(z_stream));
+		if (!rctx->zlib_stream) {
+			error("failed to allocate zlib stream %m");
+			return -ENOMEM;
+		}
+	}
+	rctx->zlib_stream->next_in = (void *)encoded_data;
+	rctx->zlib_stream->avail_in = encoded_len;
+	rctx->zlib_stream->next_out = (void *)unencoded_data;
+	rctx->zlib_stream->avail_out = unencoded_len;
+
+	if (init) {
+		rctx->zlib_stream->zalloc = Z_NULL;
+		rctx->zlib_stream->zfree = Z_NULL;
+		rctx->zlib_stream->opaque = Z_NULL;
+		ret = inflateInit(rctx->zlib_stream);
+	} else {
+		ret = inflateReset(rctx->zlib_stream);
+	}
+	if (ret != Z_OK) {
+		error("zlib inflate init failed: %d", ret);
+		return -EIO;
+	}
+
+	while (rctx->zlib_stream->avail_in > 0 &&
+	       rctx->zlib_stream->avail_out > 0) {
+		ret = inflate(rctx->zlib_stream, Z_FINISH);
+		if (ret == Z_STREAM_END) {
+			break;
+		} else if (ret != Z_OK) {
+			error("zlib inflate failed: %d", ret);
+			return -EIO;
+		}
+	}
+	return 0;
+}
+
+static int decompress_zstd(struct btrfs_receive *rctx, const char *encoded_buf,
+			   u64 encoded_len, char *unencoded_buf,
+			   u64 unencoded_len)
+{
+	ZSTD_inBuffer in_buf = {
+		.src = encoded_buf,
+		.size = encoded_len
+	};
+	ZSTD_outBuffer out_buf = {
+		.dst = unencoded_buf,
+		.size = unencoded_len
+	};
+	size_t ret;
+
+	if (!rctx->zstd_dstream) {
+		rctx->zstd_dstream = ZSTD_createDStream();
+		if (!rctx->zstd_dstream) {
+			error("failed to create zstd dstream");
+			return -ENOMEM;
+		}
+	}
+	ret = ZSTD_initDStream(rctx->zstd_dstream);
+	if (ZSTD_isError(ret)) {
+		error("failed to init zstd stream: %s", ZSTD_getErrorName(ret));
+		return -EIO;
+	}
+	while (in_buf.pos < in_buf.size && out_buf.pos < out_buf.size) {
+		ret = ZSTD_decompressStream(rctx->zstd_dstream, &out_buf, &in_buf);
+		if (ret == 0) {
+			break;
+		} else if (ZSTD_isError(ret)) {
+			error("failed to decompress zstd stream: %s",
+			      ZSTD_getErrorName(ret));
+			return -EIO;
+		}
+	}
+	return 0;
+}
+
+static int decompress_lzo(const char *encoded_data, u64 encoded_len,
+			  char *unencoded_data, u64 unencoded_len,
+			  unsigned int page_size)
+{
+	uint32_t total_len;
+	size_t in_pos, out_pos;
+
+	if (encoded_len < 4) {
+		error("lzo header is truncated");
+		return -EIO;
+	}
+	memcpy(&total_len, encoded_data, 4);
+	total_len = le32toh(total_len);
+	if (total_len > encoded_len) {
+		error("lzo header is invalid");
+		return -EIO;
+	}
+
+	in_pos = 4;
+	out_pos = 0;
+	while (in_pos < total_len && out_pos < unencoded_len) {
+		size_t page_remaining;
+		uint32_t src_len;
+		lzo_uint dst_len;
+		int ret;
+
+		page_remaining = -in_pos % page_size;
+		if (page_remaining < 4) {
+			if (total_len - in_pos <= page_remaining)
+				break;
+			in_pos += page_remaining;
+		}
+
+		if (total_len - in_pos < 4) {
+			error("lzo segment header is truncated");
+			return -EIO;
+		}
+
+		memcpy(&src_len, encoded_data + in_pos, 4);
+		src_len = le32toh(src_len);
+		in_pos += 4;
+		if (src_len > total_len - in_pos) {
+			error("lzo segment header is invalid");
+			return -EIO;
+		}
+
+		dst_len = page_size;
+		ret = lzo1x_decompress_safe((void *)(encoded_data + in_pos),
+					    src_len,
+					    (void *)(unencoded_data + out_pos),
+					    &dst_len, NULL);
+		if (ret != LZO_E_OK) {
+			error("lzo1x_decompress_safe failed: %d", ret);
+			return -EIO;
+		}
+
+		in_pos += src_len;
+		out_pos += dst_len;
+	}
+	return 0;
+}
+
+static int decompress_and_write(struct btrfs_receive *rctx,
+				const char *encoded_data, u64 offset,
+				u64 encoded_len, u64 unencoded_file_len,
+				u64 unencoded_len, u64 unencoded_offset,
+				u32 compression)
+{
+	int ret = 0;
+	size_t pos;
+	ssize_t w;
+	char *unencoded_data;
+	int page_shift;
+
+	unencoded_data = calloc(unencoded_len, 1);
+	if (!unencoded_data) {
+		error("allocating space for unencoded data failed: %m");
+		return -errno;
+	}
+
+	switch (compression) {
+	case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
+		ret = decompress_zlib(rctx, encoded_data, encoded_len,
+				      unencoded_data, unencoded_len);
+		if (ret)
+			goto out;
+		break;
+	case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
+		ret = decompress_zstd(rctx, encoded_data, encoded_len,
+				      unencoded_data, unencoded_len);
+		if (ret)
+			goto out;
+		break;
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
+	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
+		page_shift = compression - BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12;
+		ret = decompress_lzo(encoded_data, encoded_len, unencoded_data,
+				     unencoded_len, 1U << page_shift);
+		if (ret)
+			goto out;
+		break;
+	default:
+		error("unknown compression: %d", compression);
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	pos = unencoded_offset;
+	while (pos < unencoded_file_len) {
+		w = pwrite(rctx->write_fd, unencoded_data + pos,
+			   unencoded_file_len - pos, offset);
+		if (w < 0) {
+			ret = -errno;
+			error("writing unencoded data failed: %m");
+			goto out;
+		}
+		pos += w;
+		offset += w;
+	}
+out:
+	free(unencoded_data);
+	return ret;
+}
+
 static int process_encoded_write(const char *path, const void *data, u64 offset,
-	u64 len, u64 unencoded_file_len, u64 unencoded_len,
-	u64 unencoded_offset, u32 compression, u32 encryption, void *user)
+				 u64 len, u64 unencoded_file_len,
+				 u64 unencoded_len, u64 unencoded_offset,
+				 u32 compression, u32 encryption, void *user)
 {
 	int ret;
 	struct btrfs_receive *rctx = user;
@@ -1007,6 +1230,7 @@ static int process_encoded_write(const char *path, const void *data, u64 offset,
 		.compression = compression,
 		.encryption = encryption,
 	};
+	bool encoded_write = !rctx->force_decompress;
 
 	if (encryption) {
 		error("encoded_write: encryption not supported");
@@ -1023,13 +1247,21 @@ static int process_encoded_write(const char *path, const void *data, u64 offset,
 	if (ret < 0)
 		return ret;
 
-	ret = ioctl(rctx->write_fd, BTRFS_IOC_ENCODED_WRITE, &encoded);
-	if (ret < 0) {
-		ret = -errno;
-		error("encoded_write: writing to %s failed: %m", path);
-		return ret;
+	if (encoded_write) {
+		ret = ioctl(rctx->write_fd, BTRFS_IOC_ENCODED_WRITE, &encoded);
+		if (ret >= 0)
+			return 0;
+		/* Fall back for these errors, fail hard for anything else. */
+		if (errno != ENOSPC && errno != ENOTTY && errno != EINVAL) {
+			ret = -errno;
+			error("encoded_write: writing to %s failed: %m", path);
+			return ret;
+		}
 	}
-	return 0;
+
+	return decompress_and_write(rctx, data, offset, len, unencoded_file_len,
+				    unencoded_len, unencoded_offset,
+				    compression);
 }
 
 static struct btrfs_send_ops send_ops = {
@@ -1209,6 +1441,12 @@ out:
 		close(rctx->dest_dir_fd);
 		rctx->dest_dir_fd = -1;
 	}
+	if (rctx->zstd_dstream)
+		ZSTD_freeDStream(rctx->zstd_dstream);
+	if (rctx->zlib_stream) {
+		inflateEnd(rctx->zlib_stream);
+		free(rctx->zlib_stream);
+	}
 
 	return ret;
 }
@@ -1239,6 +1477,9 @@ static const char * const cmd_receive_usage[] = {
 	"-m ROOTMOUNT     the root mount point of the destination filesystem.",
 	"                 If /proc is not accessible, use this to tell us where",
 	"                 this file system is mounted.",
+	"--force-decompress",
+	"                 if the stream contains compressed data, always",
+	"                 decompress it instead of writing it with encoded I/O",
 	"--dump           dump stream metadata, one line per operation,",
 	"                 does not require the MOUNT parameter",
 	"-v               deprecated, alias for global -v option",
@@ -1282,12 +1523,16 @@ static int cmd_receive(const struct cmd_struct *cmd, int argc, char **argv)
 	optind = 0;
 	while (1) {
 		int c;
-		enum { GETOPT_VAL_DUMP = 257 };
+		enum {
+			GETOPT_VAL_DUMP = 257,
+			GETOPT_VAL_FORCE_DECOMPRESS,
+		};
 		static const struct option long_opts[] = {
 			{ "max-errors", required_argument, NULL, 'E' },
 			{ "chroot", no_argument, NULL, 'C' },
 			{ "dump", no_argument, NULL, GETOPT_VAL_DUMP },
 			{ "quiet", no_argument, NULL, 'q' },
+			{ "force-decompress", no_argument, NULL, GETOPT_VAL_FORCE_DECOMPRESS },
 			{ NULL, 0, NULL, 0 }
 		};
 
@@ -1330,6 +1575,9 @@ static int cmd_receive(const struct cmd_struct *cmd, int argc, char **argv)
 		case GETOPT_VAL_DUMP:
 			dump = 1;
 			break;
+		case GETOPT_VAL_FORCE_DECOMPRESS:
+			rctx.force_decompress = 1;
+			break;
 		default:
 			usage_unknown_option(cmd, argv);
 		}
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (19 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-21 14:21   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 08/10] btrfs-progs: receive: process setflags ioctl commands Omar Sandoval
                   ` (2 subsequent siblings)
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

Send stream v2 can emit fallocate commands, so receive must support them
as well. The implementation simply passes along the arguments to the
syscall. Note that mode is encoded as a u32 in send stream but fallocate
takes an int, so there is a unsigned->signed conversion there.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 cmds/receive-dump.c  |  9 +++++++++
 cmds/receive.c       | 25 +++++++++++++++++++++++++
 common/send-stream.c |  9 +++++++++
 common/send-stream.h |  2 ++
 4 files changed, 45 insertions(+)

diff --git a/cmds/receive-dump.c b/cmds/receive-dump.c
index 20ec2b70..acc0ba32 100644
--- a/cmds/receive-dump.c
+++ b/cmds/receive-dump.c
@@ -329,6 +329,14 @@ static int print_encoded_write(const char *path, const void *data, u64 offset,
 			  unencoded_offset, compression, encryption);
 }
 
+static int print_fallocate(const char *path, int mode, u64 offset, u64 len,
+			   void *user)
+{
+	return PRINT_DUMP(user, path, "fallocate",
+			  "mode=%d offset=%llu len=%llu",
+			  mode, offset, len);
+}
+
 struct btrfs_send_ops btrfs_print_send_ops = {
 	.subvol = print_subvol,
 	.snapshot = print_snapshot,
@@ -352,4 +360,5 @@ struct btrfs_send_ops btrfs_print_send_ops = {
 	.utimes = print_utimes,
 	.update_extent = print_update_extent,
 	.encoded_write = print_encoded_write,
+	.fallocate = print_fallocate,
 };
diff --git a/cmds/receive.c b/cmds/receive.c
index 2eebcfd1..953d7217 100644
--- a/cmds/receive.c
+++ b/cmds/receive.c
@@ -1264,6 +1264,30 @@ static int process_encoded_write(const char *path, const void *data, u64 offset,
 				    compression);
 }
 
+static int process_fallocate(const char *path, int mode, u64 offset, u64 len,
+			     void *user)
+{
+	int ret;
+	struct btrfs_receive *rctx = user;
+	char full_path[PATH_MAX];
+
+	ret = path_cat_out(full_path, rctx->full_subvol_path, path);
+	if (ret < 0) {
+		error("fallocate: path invalid: %s", path);
+		return ret;
+	}
+	ret = open_inode_for_write(rctx, full_path);
+	if (ret < 0)
+		return ret;
+	ret = fallocate(rctx->write_fd, mode, offset, len);
+	if (ret < 0) {
+		ret = -errno;
+		error("fallocate: fallocate on %s failed: %m", path);
+		return ret;
+	}
+	return 0;
+}
+
 static struct btrfs_send_ops send_ops = {
 	.subvol = process_subvol,
 	.snapshot = process_snapshot,
@@ -1287,6 +1311,7 @@ static struct btrfs_send_ops send_ops = {
 	.utimes = process_utimes,
 	.update_extent = process_update_extent,
 	.encoded_write = process_encoded_write,
+	.fallocate = process_fallocate,
 };
 
 static int do_receive(struct btrfs_receive *rctx, const char *tomnt,
diff --git a/common/send-stream.c b/common/send-stream.c
index 044e101b..bc41396e 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -369,6 +369,7 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 	u64 unencoded_offset;
 	int len;
 	int xattr_len;
+	int fallocate_mode;
 
 	ret = read_cmd(sctx);
 	if (ret)
@@ -514,6 +515,14 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 	case BTRFS_SEND_C_END:
 		ret = 1;
 		break;
+	case BTRFS_SEND_C_FALLOCATE:
+		TLV_GET_STRING(sctx, BTRFS_SEND_A_PATH, &path);
+		TLV_GET_U32(sctx, BTRFS_SEND_A_FALLOCATE_MODE, &fallocate_mode);
+		TLV_GET_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, &offset);
+		TLV_GET_U64(sctx, BTRFS_SEND_A_SIZE, &tmp);
+		ret = sctx->ops->fallocate(path, fallocate_mode, offset, tmp,
+					   sctx->user);
+		break;
 	}
 
 tlv_get_failed:
diff --git a/common/send-stream.h b/common/send-stream.h
index 607bc007..a58739bb 100644
--- a/common/send-stream.h
+++ b/common/send-stream.h
@@ -70,6 +70,8 @@ struct btrfs_send_ops {
 			     u64 len, u64 unencoded_file_len, u64 unencoded_len,
 			     u64 unencoded_offset, u32 compression,
 			     u32 encryption, void *user);
+	int (*fallocate)(const char *path, int mode, u64 offset, u64 len,
+			 void *user);
 };
 
 int btrfs_read_and_process_send_stream(int fd,
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 08/10] btrfs-progs: receive: process setflags ioctl commands
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (20 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-21 14:22   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 09/10] btrfs-progs: send: stream v2 ioctl flags Omar Sandoval
  2021-09-01 17:01 ` [PATCH v11 10/10] btrfs-progs: receive: add tests for basic encoded_write send/receive Omar Sandoval
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

In send stream v2, send can emit a command for setting inode flags via
the setflags ioctl. Pass the flags attribute through to the ioctl call
in receive.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 cmds/receive-dump.c  |  6 ++++++
 cmds/receive.c       | 25 +++++++++++++++++++++++++
 common/send-stream.c |  7 +++++++
 common/send-stream.h |  1 +
 4 files changed, 39 insertions(+)

diff --git a/cmds/receive-dump.c b/cmds/receive-dump.c
index acc0ba32..40f07ad4 100644
--- a/cmds/receive-dump.c
+++ b/cmds/receive-dump.c
@@ -337,6 +337,11 @@ static int print_fallocate(const char *path, int mode, u64 offset, u64 len,
 			  mode, offset, len);
 }
 
+static int print_setflags(const char *path, int flags, void *user)
+{
+	return PRINT_DUMP(user, path, "setflags", "flags=%d", flags);
+}
+
 struct btrfs_send_ops btrfs_print_send_ops = {
 	.subvol = print_subvol,
 	.snapshot = print_snapshot,
@@ -361,4 +366,5 @@ struct btrfs_send_ops btrfs_print_send_ops = {
 	.update_extent = print_update_extent,
 	.encoded_write = print_encoded_write,
 	.fallocate = print_fallocate,
+	.setflags = print_setflags,
 };
diff --git a/cmds/receive.c b/cmds/receive.c
index 953d7217..f5060117 100644
--- a/cmds/receive.c
+++ b/cmds/receive.c
@@ -38,6 +38,7 @@
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <sys/xattr.h>
+#include <linux/fs.h>
 #include <uuid/uuid.h>
 
 #include <lzo/lzo1x.h>
@@ -1288,6 +1289,29 @@ static int process_fallocate(const char *path, int mode, u64 offset, u64 len,
 	return 0;
 }
 
+static int process_setflags(const char *path, int flags, void *user)
+{
+	int ret;
+	struct btrfs_receive *rctx = user;
+	char full_path[PATH_MAX];
+
+	ret = path_cat_out(full_path, rctx->full_subvol_path, path);
+	if (ret < 0) {
+		error("setflags: path invalid: %s", path);
+		return ret;
+	}
+	ret = open_inode_for_write(rctx, full_path);
+	if (ret < 0)
+		return ret;
+	ret = ioctl(rctx->write_fd, FS_IOC_SETFLAGS, &flags);
+	if (ret < 0) {
+		ret = -errno;
+		error("setflags: setflags ioctl on %s failed: %m", path);
+		return ret;
+	}
+	return 0;
+}
+
 static struct btrfs_send_ops send_ops = {
 	.subvol = process_subvol,
 	.snapshot = process_snapshot,
@@ -1312,6 +1336,7 @@ static struct btrfs_send_ops send_ops = {
 	.update_extent = process_update_extent,
 	.encoded_write = process_encoded_write,
 	.fallocate = process_fallocate,
+	.setflags = process_setflags,
 };
 
 static int do_receive(struct btrfs_receive *rctx, const char *tomnt,
diff --git a/common/send-stream.c b/common/send-stream.c
index bc41396e..b9d35a34 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -370,6 +370,7 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 	int len;
 	int xattr_len;
 	int fallocate_mode;
+	int setflags_flags;
 
 	ret = read_cmd(sctx);
 	if (ret)
@@ -523,8 +524,14 @@ static int read_and_process_cmd(struct btrfs_send_stream *sctx)
 		ret = sctx->ops->fallocate(path, fallocate_mode, offset, tmp,
 					   sctx->user);
 		break;
+	case BTRFS_SEND_C_SETFLAGS:
+		TLV_GET_STRING(sctx, BTRFS_SEND_A_PATH, &path);
+		TLV_GET_U32(sctx, BTRFS_SEND_A_SETFLAGS_FLAGS, &setflags_flags);
+		ret = sctx->ops->setflags(path, setflags_flags, sctx->user);
+		break;
 	}
 
+
 tlv_get_failed:
 out:
 	free(path);
diff --git a/common/send-stream.h b/common/send-stream.h
index a58739bb..5373bf69 100644
--- a/common/send-stream.h
+++ b/common/send-stream.h
@@ -72,6 +72,7 @@ struct btrfs_send_ops {
 			     u32 encryption, void *user);
 	int (*fallocate)(const char *path, int mode, u64 offset, u64 len,
 			 void *user);
+	int (*setflags)(const char *path, int flags, void *user);
 };
 
 int btrfs_read_and_process_send_stream(int fd,
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 09/10] btrfs-progs: send: stream v2 ioctl flags
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (21 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 08/10] btrfs-progs: receive: process setflags ioctl commands Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  2021-10-22  6:35   ` Nikolay Borisov
  2021-09-01 17:01 ` [PATCH v11 10/10] btrfs-progs: receive: add tests for basic encoded_write send/receive Omar Sandoval
  23 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

To make the btrfs send ioctl use the stream v2 format requires passing
BTRFS_SEND_FLAG_STREAM_V2 in flags. Further, to cause the ioctl to emit
encoded_write commands for encoded extents, we must set that flag as
well as BTRFS_SEND_FLAG_COMPRESSED. Finally, we bump up the version in
send.h as well, since we are now fully compatible with v2.

Add two command line arguments to btrfs send: --stream-version and
--compressed-data. --stream-version requires an argument which it parses
as an integer and sets STREAM_V2 if the argument is 2. --compressed-data
does not require an argument and automatically implies STREAM_V2 as well
(COMPRESSED alone causes the ioctl to error out).

Some examples to illustrate edge cases:

// v1, old format and no encoded_writes
btrfs send subvol
btrfs send --stream-version 1 subvol

// v2 and compressed, we will see encoded_writes
btrfs send --compressed-data subvol
btrfs send --compressed-data --stream-version 2 subvol

// v2 only, new format but no encoded_writes
btrfs send --stream-version 2 subvol

// error: compressed needs version >= 2
btrfs send --compressed-data --stream-version 1 subvol

// error: invalid version (not 1 or 2)
btrfs send --stream-version 3 subvol
btrfs send --compressed-data --stream-version 0 subvol
btrfs send --compressed-data --stream-version 10 subvol

Signed-off-by: Boris Burkov <boris@bur.io>
---
 Documentation/btrfs-send.asciidoc | 16 ++++++++-
 cmds/send.c                       | 54 ++++++++++++++++++++++++++++++-
 ioctl.h                           | 17 +++++++++-
 libbtrfsutil/btrfs.h              | 17 +++++++++-
 send.h                            |  2 +-
 5 files changed, 101 insertions(+), 5 deletions(-)

diff --git a/Documentation/btrfs-send.asciidoc b/Documentation/btrfs-send.asciidoc
index c4a05672..202bcd97 100644
--- a/Documentation/btrfs-send.asciidoc
+++ b/Documentation/btrfs-send.asciidoc
@@ -55,7 +55,21 @@ send in 'NO_FILE_DATA' mode
 The output stream does not contain any file
 data and thus cannot be used to transfer changes. This mode is faster and
 is useful to show the differences in metadata.
--q|--quiet::::
+
+--stream-version <1|2>::
+Use the given send stream version. The default is 1. Version 2 encodes file
+data slightly more efficiently; it is also required for sending compressed data
+directly (see '--compressed-data'). Version 2 requires at least btrfs-progs
+5.12 on both the sender and receiver and at least Linux 5.12 on the sender.
+
+--compressed-data::
+Send data that is compressed on the filesystem directly without decompressing
+it. If the receiver supports encoded I/O (see `encoded_io`(7)), it can also
+write it directly without decompressing it. Otherwise, the receiver will fall
+back to decompressing it and writing it normally. This implies
+'--stream-version 2'.
+
+-q|--quiet::
 (deprecated) alias for global '-q' option
 -v|--verbose::
 (deprecated) alias for global '-v' option
diff --git a/cmds/send.c b/cmds/send.c
index 3bfc69f5..80eb2510 100644
--- a/cmds/send.c
+++ b/cmds/send.c
@@ -452,6 +452,21 @@ static const char * const cmd_send_usage[] = {
 	"                 does not contain any file data and thus cannot be used",
 	"                 to transfer changes. This mode is faster and useful to",
 	"                 show the differences in metadata.",
+	"--stream-version <1|2>",
+	"                 Use the given send stream version. The default is",
+	"                 1. Version 2 encodes file data slightly more",
+	"                 efficiently; it is also required for sending",
+	"                 compressed data directly (see --compressed-data).",
+	"                 Version 2 requires at least btrfs-progs 5.12 on both",
+	"                 the sender and receiver and at least Linux 5.12 on the",
+	"                 sender.",
+	"--compressed-data",
+	"                 Send data that is compressed on the filesystem",
+	"                 directly without decompressing it. If the receiver",
+	"                 supports encoded I/O, it can also write it directly",
+	"                 without decompressing it. Otherwise, the receiver will",
+	"                 fall back to decompressing it and writing it normally.",
+	"                 This implies --stream-version 2.",
 	"-v|--verbose     deprecated, alias for global -v option",
 	"-q|--quiet       deprecated, alias for global -q option",
 	HELPINFO_INSERT_GLOBALS,
@@ -463,6 +478,7 @@ static const char * const cmd_send_usage[] = {
 static int cmd_send(const struct cmd_struct *cmd, int argc, char **argv)
 {
 	char *subvol = NULL;
+	char *end;
 	int ret;
 	char outname[PATH_MAX];
 	struct btrfs_send send;
@@ -474,6 +490,7 @@ static int cmd_send(const struct cmd_struct *cmd, int argc, char **argv)
 	int full_send = 1;
 	int new_end_cmd_semantic = 0;
 	u64 send_flags = 0;
+	long stream_version = 0;
 
 	memset(&send, 0, sizeof(send));
 	send.dump_fd = fileno(stdout);
@@ -492,11 +509,17 @@ static int cmd_send(const struct cmd_struct *cmd, int argc, char **argv)
 
 	optind = 0;
 	while (1) {
-		enum { GETOPT_VAL_SEND_NO_DATA = 256 };
+		enum {
+			GETOPT_VAL_SEND_NO_DATA = 256,
+			GETOPT_VAL_SEND_STREAM_V2,
+			GETOPT_VAL_SEND_COMPRESSED_DATA,
+		};
 		static const struct option long_options[] = {
 			{ "verbose", no_argument, NULL, 'v' },
 			{ "quiet", no_argument, NULL, 'q' },
 			{ "no-data", no_argument, NULL, GETOPT_VAL_SEND_NO_DATA },
+			{ "stream-version", required_argument, NULL, GETOPT_VAL_SEND_STREAM_V2 },
+			{ "compressed-data", no_argument, NULL, GETOPT_VAL_SEND_COMPRESSED_DATA },
 			{ NULL, 0, NULL, 0 }
 		};
 		int c = getopt_long(argc, argv, "vqec:f:i:p:", long_options, NULL);
@@ -585,10 +608,39 @@ static int cmd_send(const struct cmd_struct *cmd, int argc, char **argv)
 		case GETOPT_VAL_SEND_NO_DATA:
 			send_flags |= BTRFS_SEND_FLAG_NO_FILE_DATA;
 			break;
+		case GETOPT_VAL_SEND_STREAM_V2:
+			stream_version = strtol(optarg, &end, 10);
+			if (*end != '\0' ||
+			    stream_version < 1 || stream_version > 2) {
+				ret = 1;
+				error("invalid --stream-version. valid values: {1, 2}");
+				goto out;
+			}
+			if (stream_version == 2)
+				send_flags |= BTRFS_SEND_FLAG_STREAM_V2;
+			break;
+		case GETOPT_VAL_SEND_COMPRESSED_DATA:
+			send_flags |= BTRFS_SEND_FLAG_COMPRESSED;
+			/*
+			 * We want to default to stream v2 if only compressed is
+			 * set. If stream_version is explicitly set to 0, that
+			 * will trigger its own error condition for being an
+			 * invalid version.
+			 */
+			if (stream_version == 0) {
+				stream_version = 2;
+				send_flags |= BTRFS_SEND_FLAG_STREAM_V2;
+			}
+			break;
 		default:
 			usage_unknown_option(cmd, argv);
 		}
 	}
+	if (stream_version < 2 && (send_flags & BTRFS_SEND_FLAG_COMPRESSED)) {
+		ret = 1;
+		error("--compressed requires --stream-version >= 2");
+		goto out;
+	}
 
 	if (check_argc_min(argc - optind, 1))
 		return 1;
diff --git a/ioctl.h b/ioctl.h
index 90e283c8..03144f79 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -653,10 +653,25 @@ BUILD_ASSERT(sizeof(struct btrfs_ioctl_received_subvol_args_32) == 192);
  */
 #define BTRFS_SEND_FLAG_OMIT_END_CMD		0x4
 
+/*
+ * Use version 2 of the send stream, which adds new commands and supports larger
+ * writes.
+ */
+#define BTRFS_SEND_FLAG_STREAM_V2		0x8
+
+/*
+ * Send compressed data using the ENCODED_WRITE command instead of decompressing
+ * the data and sending it with the WRITE command. This requires
+ * BTRFS_SEND_FLAG_STREAM_V2.
+ */
+#define BTRFS_SEND_FLAG_COMPRESSED		0x10
+
 #define BTRFS_SEND_FLAG_MASK \
 	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
 	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \
-	 BTRFS_SEND_FLAG_OMIT_END_CMD)
+	 BTRFS_SEND_FLAG_OMIT_END_CMD | \
+	 BTRFS_SEND_FLAG_STREAM_V2 | \
+	 BTRFS_SEND_FLAG_COMPRESSED)
 
 struct btrfs_ioctl_send_args {
 	__s64 send_fd;			/* in */
diff --git a/libbtrfsutil/btrfs.h b/libbtrfsutil/btrfs.h
index a3117362..76022b7c 100644
--- a/libbtrfsutil/btrfs.h
+++ b/libbtrfsutil/btrfs.h
@@ -731,10 +731,25 @@ struct btrfs_ioctl_received_subvol_args {
  */
 #define BTRFS_SEND_FLAG_OMIT_END_CMD		0x4
 
+/*
+ * Use version 2 of the send stream, which adds new commands and supports larger
+ * writes.
+ */
+#define BTRFS_SEND_FLAG_STREAM_V2		0x8
+
+/*
+ * Send compressed data using the ENCODED_WRITE command instead of decompressing
+ * the data and sending it with the WRITE command. This requires
+ * BTRFS_SEND_FLAG_STREAM_V2.
+ */
+#define BTRFS_SEND_FLAG_COMPRESSED		0x10
+
 #define BTRFS_SEND_FLAG_MASK \
 	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
 	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \
-	 BTRFS_SEND_FLAG_OMIT_END_CMD)
+	 BTRFS_SEND_FLAG_OMIT_END_CMD | \
+	 BTRFS_SEND_FLAG_STREAM_V2 | \
+	 BTRFS_SEND_FLAG_COMPRESSED)
 
 struct btrfs_ioctl_send_args {
 	__s64 send_fd;			/* in */
diff --git a/send.h b/send.h
index 3c47e0c7..fac90588 100644
--- a/send.h
+++ b/send.h
@@ -31,7 +31,7 @@ extern "C" {
 #endif
 
 #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
-#define BTRFS_SEND_STREAM_VERSION 1
+#define BTRFS_SEND_STREAM_VERSION 2
 
 #define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
 #define BTRFS_SEND_READ_SIZE (1024 * 48)
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* [PATCH v11 10/10] btrfs-progs: receive: add tests for basic encoded_write send/receive
  2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
                   ` (22 preceding siblings ...)
  2021-09-01 17:01 ` [PATCH v11 09/10] btrfs-progs: send: stream v2 ioctl flags Omar Sandoval
@ 2021-09-01 17:01 ` Omar Sandoval
  23 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-09-01 17:01 UTC (permalink / raw)
  To: linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api

From: Boris Burkov <boris@bur.io>

Adapt the existing send/receive tests by passing '-o --force-compress'
to the mount commands in a new test. After writing a few files in the
various compression formats, send/receive them with and without
--force-decompress to test both the encoded_write path and the
fallback to decode+write.

Signed-off-by: Boris Burkov <boris@bur.io>
---
 .../049-receive-write-encoded/test.sh         | 114 ++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100755 tests/misc-tests/049-receive-write-encoded/test.sh

diff --git a/tests/misc-tests/049-receive-write-encoded/test.sh b/tests/misc-tests/049-receive-write-encoded/test.sh
new file mode 100755
index 00000000..b9390e88
--- /dev/null
+++ b/tests/misc-tests/049-receive-write-encoded/test.sh
@@ -0,0 +1,114 @@
+#!/bin/bash
+#
+# test that we can send and receive encoded writes for three modes of
+# transparent compression: zlib, lzo, and zstd.
+
+source "$TEST_TOP/common"
+
+check_prereq mkfs.btrfs
+check_prereq btrfs
+
+setup_root_helper
+prepare_test_dev
+
+here=`pwd`
+
+# assumes the filesystem exists, and does mount, write, snapshot, send, unmount
+# for the specified encoding option
+send_one() {
+	local str
+	local subv
+	local snap
+
+	algorithm="$1"
+	shift
+	str="$1"
+	shift
+
+	subv="subv-$algorithm"
+	snap="snap-$algorithm"
+
+	run_check_mount_test_dev "-o" "compress-force=$algorithm"
+	cd "$TEST_MNT" || _fail "cannot chdir to TEST_MNT"
+
+	run_check $SUDO_HELPER "$TOP/btrfs" subvolume create "$subv"
+	run_check $SUDO_HELPER dd if=/dev/zero of="$subv/file1" bs=1M count=1
+	run_check $SUDO_HELPER dd if=/dev/zero of="$subv/file2" bs=500K count=1
+	run_check $SUDO_HELPER "$TOP/btrfs" subvolume snapshot -r "$subv" "$snap"
+	run_check $SUDO_HELPER "$TOP/btrfs" send -f "$str" "$snap" "$@"
+
+	cd "$here" || _fail "cannot chdir back to test directory"
+	run_check_umount_test_dev
+}
+
+receive_one() {
+	local str
+	str="$1"
+	shift
+
+	run_check_mkfs_test_dev
+	run_check_mount_test_dev
+	run_check $SUDO_HELPER "$TOP/btrfs" receive "$@" -v -f "$str" "$TEST_MNT"
+	run_check_umount_test_dev
+	run_check rm -f -- "$str"
+}
+
+test_one_write_encoded() {
+	local str
+	local algorithm
+	algorithm="$1"
+	shift
+	str="$here/stream-$algorithm.stream"
+
+	run_check_mkfs_test_dev
+	send_one "$algorithm" "$str" --compressed-data
+	receive_one "$str" "$@"
+}
+
+test_one_stream_v1() {
+	local str
+	local algorithm
+	algorithm="$1"
+	shift
+	str="$here/stream-$algorithm.stream"
+
+	run_check_mkfs_test_dev
+	send_one "$algorithm" "$str" --stream-version 1
+	receive_one "$str" "$@"
+}
+
+test_mix_write_encoded() {
+	local strzlib
+	local strlzo
+	local strzstd
+	strzlib="$here/stream-zlib.stream"
+	strlzo="$here/stream-lzo.stream"
+	strzstd="$here/stream-zstd.stream"
+
+	run_check_mkfs_test_dev
+
+	send_one "zlib" "$strzlib" --compressed-data
+	send_one "lzo" "$strlzo" --compressed-data
+	send_one "zstd" "$strzstd" --compressed-data
+
+	receive_one "$strzlib"
+	receive_one "$strlzo"
+	receive_one "$strzstd"
+}
+
+test_one_write_encoded "zlib"
+test_one_write_encoded "lzo"
+test_one_write_encoded "zstd"
+
+# with decompression forced
+test_one_write_encoded "zlib" "--force-decompress"
+test_one_write_encoded "lzo" "--force-decompress"
+test_one_write_encoded "zstd" "--force-decompress"
+
+# send stream v1
+test_one_stream_v1 "zlib"
+test_one_stream_v1 "lzo"
+test_one_stream_v1 "zstd"
+
+# files use a mix of compression algorithms
+test_mix_write_encoded
-- 
2.33.0


^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 02/14] fs: export variant of generic_write_checks without iov_iter
  2021-09-01 17:00 ` [PATCH v11 02/14] fs: export variant of generic_write_checks without iov_iter Omar Sandoval
@ 2021-10-14 12:03   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-14 12:03 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:00, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Encoded I/O in Btrfs needs to check a write with a given logical size
> without an iov_iter that matches that size (because the iov_iter we have
> is for the compressed data). So, factor out the parts of
> generic_write_check() that don't need an iov_iter into a new
> generic_write_checks_count() function and export that.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio()
  2021-09-01 17:00 ` [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio() Omar Sandoval
@ 2021-10-14 12:05   ` Nikolay Borisov
  2021-10-18 18:09     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-14 12:05 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:00, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> btrfs_csum_one_bio() loops over each filesystem block in the bio while
> keeping a cursor of its current logical position in the file in order to
> look up the ordered extent to add the checksums to. However, this
> doesn't make much sense for compressed extents, as a sector on disk does
> not correspond to a sector of decompressed file data. It happens to work
> because 1) the compressed bio always covers one ordered extent and 2)
> the size of the bio is always less than the size of the ordered extent.
> However, the second point will not always be true for encoded writes.
> 
> Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that
> it can assume that the bio only covers one ordered extent. Since we're
> already changing the signature, let's get rid of the contig parameter
> and make it implied by the offset parameter, similar to the change we
> recently made to btrfs_lookup_bio_sums(). Additionally, let's rename
> nr_sectors to blockcount to make it clear that it's the number of
> filesystem blocks, not the number of 512-byte sectors.
> 
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Code-wise this looks, though I don't know why we are guaranteed that a
compressed extent will only cover a single OE. But I trust you so:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 06/14] btrfs: optionally extend i_size in cow_file_range_inline()
  2021-09-01 17:01 ` [PATCH v11 06/14] btrfs: optionally extend i_size in cow_file_range_inline() Omar Sandoval
@ 2021-10-14 12:54   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-14 12:54 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs
  Cc: kernel-team, linux-fsdevel, linux-api, Qu Wenruo



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Currently, an inline extent is always created after i_size is extended
> from btrfs_dirty_pages(). However, for encoded writes, we only want to
> update i_size after we successfully created the inline extent. Add an
> update_i_size parameter to cow_file_range_inline() and
> insert_inline_extent() and pass in the size of the extent rather than
> determining it from i_size. Since the start parameter is always passed
> as 0, get rid of it and simplify the logic in these two functions. While
> we're here, let's document the requirements for creating an inline
> extent.
> 
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Omar Sandoval <osandov@fb.com>


Overall I like where this is going, actually the diff is larger than it
should be because some refactoring is tucked in. If there would be yet
another submission with more substantial changes I'd like to see this
patch split into 2:

1. Patch does the refactoring

2. Adds the logic to update i_size alongside the addition of the
update_i_size parameter.

That will make the functional change a lot more obvious.

> ---
>  fs/btrfs/inode.c | 100 +++++++++++++++++++++++------------------------
>  1 file changed, 48 insertions(+), 52 deletions(-)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 6aad4b641d5c..a87a34f56234 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -236,9 +236,10 @@ static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
>  static int insert_inline_extent(struct btrfs_trans_handle *trans,
>  				struct btrfs_path *path, bool extent_inserted,
>  				struct btrfs_root *root, struct inode *inode,
> -				u64 start, size_t size, size_t compressed_size,
> +				size_t size, size_t compressed_size,
>  				int compress_type,
> -				struct page **compressed_pages)
> +				struct page **compressed_pages,
> +				bool update_i_size)

This function grows to 10 parameters, I think it's high time it took an
argument struct and each member can in turn be documented in this
structure,  otherwise it's very unwieldy to work with.

>  {
>  	struct extent_buffer *leaf;
>  	struct page *page = NULL;

<snip>


>  
> @@ -327,7 +326,13 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
>  	 * before we unlock the pages.  Otherwise we
>  	 * could end up racing with unlink.
>  	 */
> -	BTRFS_I(inode)->disk_i_size = inode->i_size;
> +	i_size = i_size_read(inode);
> +	if (update_i_size && size > i_size) {
> +		i_size_write(inode, size);
> +		i_size = size;
> +	}
> +	BTRFS_I(inode)->disk_i_size = i_size;
> +
>  fail:
>  	return ret;
>  }
> @@ -338,35 +343,31 @@ static int insert_inline_extent(struct btrfs_trans_handle *trans,
>   * does the checks required to make sure the data is small enough
>   * to fit as an inline extent.
>   */
> -static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start,
> -					  u64 end, size_t compressed_size,
> +static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 size,
> +					  size_t compressed_size,
>  					  int compress_type,
> -					  struct page **compressed_pages)
> +					  struct page **compressed_pages,
> +					  bool update_i_size)

This function also has 6 parameters which is not on the extreme but I
have a feeling it also needs to be refactored to take an argument
structure.

>  {
>  	struct btrfs_drop_extents_args drop_args = { 0 };
>  	struct btrfs_root *root = inode->root;
>  	struct btrfs_fs_info *fs_info = root->fs_info;
>  	struct btrfs_trans_handle *trans;
> -	u64 isize = i_size_read(&inode->vfs_inode);
> -	u64 actual_end = min(end + 1, isize);
> -	u64 inline_len = actual_end - start;
> -	u64 aligned_end = ALIGN(end, fs_info->sectorsize);
> -	u64 data_len = inline_len;
> +	u64 data_len = compressed_size ? compressed_size : size;
>  	int ret;
>  	struct btrfs_path *path;
>  
> -	if (compressed_size)
> -		data_len = compressed_size;
> -
> -	if (start > 0 ||
> -	    actual_end > fs_info->sectorsize ||
> +	/*
> +	 * We can create an inline extent if it ends at or beyond the current
> +	 * i_size, is no larger than a sector (decompressed), and the (possibly
> +	 * compressed) data fits in a leaf and the configured maximum inline
> +	 * size.
> +	 */
> +	if (size < i_size_read(&inode->vfs_inode) ||
> +	    size > fs_info->sectorsize ||
>  	    data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
> -	    (!compressed_size &&
> -	    (actual_end & (fs_info->sectorsize - 1)) == 0) ||
> -	    end + 1 < isize ||
> -	    data_len > fs_info->max_inline) {
> +	    data_len > fs_info->max_inline)
>  		return 1;

With this change you allow to write more than PAGE_SIZE data in case of
a compressed extents, Qu said he had some concerns regarding this. I'm
CCing him so this can be discussed on this submission.

> -	}
>  
>  	path = btrfs_alloc_path();
>  	if (!path)

<snip>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls
  2021-09-01 17:01 ` [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls Omar Sandoval
@ 2021-10-15  9:42   ` Nikolay Borisov
  2021-10-18 18:16     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-15  9:42 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> In order to allow sending and receiving compressed data without
> decompressing it, we need an interface to write pre-compressed data
> directly to the filesystem and the matching interface to read compressed
> data without decompressing it. This adds the definitions for ioctls to
> do that and detailed explanations of how to use them.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

One minor nit below but otherwise LGTM:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

<snip>

> +struct btrfs_ioctl_encoded_io_args {
> +	/* Input parameters for both reads and writes. */
> +
> +	/*
> +	 * iovecs containing encoded data.
> +	 *
> +	 * For reads, if the size of the encoded data is larger than the sum of
> +	 * iov[n].iov_len for 0 <= n < iovcnt, then the ioctl fails with
> +	 * ENOBUFS.
> +	 *
> +	 * For writes, the size of the encoded data is the sum of iov[n].iov_len
> +	 * for 0 <= n < iovcnt. This must be less than 128 KiB (this limit may
> +	 * increase in the future). This must also be less than or equal to
> +	 * unencoded_len.
> +	 */
> +	const struct iovec __user *iov;
> +	/* Number of iovecs. */
> +	unsigned long iovcnt;
> +	/*
> +	 * Offset in file.
> +	 *
> +	 * For writes, must be aligned to the sector size of the filesystem.
> +	 */
> +	__s64 offset;
> +	/* Currently must be zero. */
> +	__u64 flags;
> +

nit: A comment stating that the output params begin here could be added.

> 

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ
  2021-09-01 17:01 ` [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ Omar Sandoval
@ 2021-10-15 11:45   ` Nikolay Borisov
  2021-10-18 23:59     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-15 11:45 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> There are 4 main cases:
> 
> 1. Inline extents: we copy the data straight out of the extent buffer.
> 2. Hole/preallocated extents: we fill in zeroes.
> 3. Regular, uncompressed extents: we read the sectors we need directly
>    from disk.
> 4. Regular, compressed extents: we read the entire compressed extent
>    from disk and indicate what subset of the decompressed extent is in
>    the file.
> 
> This initial implementation simplifies a few things that can be improved
> in the future:
> 
> - We hold the inode lock during the operation.
> - Cases 1, 3, and 4 allocate temporary memory to read into before
>   copying out to userspace.
> - We don't do read repair, because it turns out that read repair is
>   currently broken for compressed data.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
>  fs/btrfs/ctree.h |   4 +
>  fs/btrfs/inode.c | 489 +++++++++++++++++++++++++++++++++++++++++++++++
>  fs/btrfs/ioctl.c | 111 +++++++++++
>  3 files changed, 604 insertions(+)
> 
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index b95ec5fb68d5..cbd7e07c1c34 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -3223,6 +3223,10 @@ int btrfs_writepage_cow_fixup(struct page *page);
>  void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
>  					  struct page *page, u64 start,
>  					  u64 end, bool uptodate);
> +struct btrfs_ioctl_encoded_io_args;
> +ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
> +			   struct btrfs_ioctl_encoded_io_args *encoded);
> +
>  extern const struct dentry_operations btrfs_dentry_operations;
>  extern const struct iomap_ops btrfs_dio_iomap_ops;
>  extern const struct iomap_dio_ops btrfs_dio_ops;
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index a87a34f56234..1940f22179ba 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -10500,6 +10500,495 @@ void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
>  	}
>  }
>  

<snip>

> +
> +static blk_status_t btrfs_encoded_read_check_bio(struct btrfs_io_bio *io_bio)

nit: The gist of this function is to check the csum so how about
renaming it to btrfs_encoded_read_verify_csum

<snip>

> +
> +static void btrfs_encoded_read_endio(struct bio *bio)
> +{
> +	struct btrfs_encoded_read_private *priv = bio->bi_private;
> +	struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
> +	blk_status_t status;
> +
> +	status = btrfs_encoded_read_check_bio(io_bio);
> +	if (status) {
> +		/*
> +		 * The memory barrier implied by the atomic_dec_return() here
> +		 * pairs with the memory barrier implied by the
> +		 * atomic_dec_return() or io_wait_event() in

nit: I think atomic_dec_return in read_regular_fill_pages is
inconsequential, what we want to ensure is that when the caller of
io_wait_event is woken up by this thread it will observe the
priv->status, which it will, because the atomic-dec_return in this
function has paired with the general barrier interpolated by wait_event.

So for brevity just leave the text to say "by io_wait_event".

> +		 * btrfs_encoded_read_regular_fill_pages() to ensure that this
> +		 * write is observed before the load of status in
> +		 * btrfs_encoded_read_regular_fill_pages().
> +		 */
> +		WRITE_ONCE(priv->status, status);
> +	}
> +	if (!atomic_dec_return(&priv->pending))
> +		wake_up(&priv->wait);
> +	btrfs_io_bio_free_csum(io_bio);
> +	bio_put(bio);
> +}

<snip>

> @@ -4824,6 +4841,94 @@ static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
>  	return ret;
>  }
>  

<snip>

> +	memset((char *)&args + copy_end_kernel, 0,
> +	       sizeof(args) - copy_end_kernel);

nit: This memset can be eliminated ( in source) by marking args = {};
and just leaving copy from user above.

> +
> +	ret = import_iovec(READ, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
> +			   &iov, &iter);
> +	if (ret < 0)
> +		goto out_acct;
> +
> +	if (iov_iter_count(&iter) == 0) {
> +		ret = 0;
> +		goto out_iov;
> +	}
> +	pos = args.offset;
> +	ret = rw_verify_area(READ, file, &pos, args.len);
> +	if (ret < 0)
> +		goto out_iov;
> +
> +	init_sync_kiocb(&kiocb, file);
> +	ret = kiocb_set_rw_flags(&kiocb, 0);

This call is a noop due to:
	if (!flags)
		return 0;

in kiocb_set_rw_flags.


<snip>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 12/14] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2
  2021-09-01 17:01 ` [PATCH v11 12/14] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2 Omar Sandoval
@ 2021-10-18 11:10   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-18 11:10 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> For encoded writes, we need the raw pages for reading compressed data
> directly via a bio. So, replace kvmalloc() with vmap() so we have access
> to the raw pages. 144k is large enough that it usually gets allocated
> with vmalloc(), anyways.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes
  2021-09-01 17:01 ` [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes Omar Sandoval
@ 2021-10-18 11:59   ` Nikolay Borisov
  2021-10-19  0:11     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-18 11:59 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Now that all of the pieces are in place, we can use the ENCODED_WRITE
> command to send compressed extents when appropriate.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Overall looks sane but consider some of the nits below.


<snip>

> +static int send_encoded_extent(struct send_ctx *sctx, struct btrfs_path *path,
> +			       u64 offset, u64 len)
> +{
> +	struct btrfs_root *root = sctx->send_root;
> +	struct btrfs_fs_info *fs_info = root->fs_info;
> +	struct inode *inode;
> +	struct fs_path *p;
> +	struct extent_buffer *leaf = path->nodes[0];
> +	struct btrfs_key key;
> +	struct btrfs_file_extent_item *ei;
> +	u64 block_start;
> +	u64 block_len;
> +	u32 data_offset;
> +	struct btrfs_cmd_header *hdr;
> +	u32 crc;
> +	int ret;
> +
> +	inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root);
> +	if (IS_ERR(inode))
> +		return PTR_ERR(inode);
> +
> +	p = fs_path_alloc();
> +	if (!p) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	ret = begin_cmd(sctx, BTRFS_SEND_C_ENCODED_WRITE);
> +	if (ret < 0)
> +		goto out;
> +
> +	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
> +	if (ret < 0)
> +		goto out;
> +
> +	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
> +	ei = btrfs_item_ptr(leaf, path->slots[0],
> +			    struct btrfs_file_extent_item);
> +	block_start = btrfs_file_extent_disk_bytenr(leaf, ei);

block_start is somewhat ambiguous here, this is just the disk bytenr of
the extent.

> +	block_len = btrfs_file_extent_disk_num_bytes(leaf, ei);

Why is this called block_len when it's just the size in bytes on-disk?

> +
> +	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
> +	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
> +	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN,
> +		    min(key.offset + btrfs_file_extent_num_bytes(leaf, ei) - offset,
> +			len));
> +	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN,
> +		    btrfs_file_extent_ram_bytes(leaf, ei));
> +	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET,
> +		    offset - key.offset + btrfs_file_extent_offset(leaf, ei));
> +	ret = btrfs_encoded_io_compression_from_extent(
> +				btrfs_file_extent_compression(leaf, ei));
> +	if (ret < 0)
> +		goto out;
> +	TLV_PUT_U32(sctx, BTRFS_SEND_A_COMPRESSION, ret);
> +	TLV_PUT_U32(sctx, BTRFS_SEND_A_ENCRYPTION, 0);
> +
> +	ret = put_data_header(sctx, block_len);
> +	if (ret < 0)
> +		goto out;
> +
> +	data_offset = ALIGN(sctx->send_size, PAGE_SIZE);

nit: The whole data_offset warrants a comment here, since send_buf is
now mapped from send_buf_pages, so all the TLV you've put before are
actually stored in the beginning of send_buf_pages, so by doing the
above you ensure the data write begins on a clean page boundary ...

> +	if (data_offset > sctx->send_max_size ||
> +	    sctx->send_max_size - data_offset < block_len) {
> +		ret = -EOVERFLOW;
> +		goto out;
> +	}
> +
> +	ret = btrfs_encoded_read_regular_fill_pages(inode, block_start,
> +						    block_len,
> +						    sctx->send_buf_pages +
> +						    (data_offset >> PAGE_SHIFT));
> +	if (ret)
> +		goto out;
> +
> +	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
> +	hdr->len = cpu_to_le32(sctx->send_size + block_len - sizeof(*hdr));
> +	hdr->crc = 0;
> +	crc = btrfs_crc32c(0, sctx->send_buf, sctx->send_size);
> +	crc = btrfs_crc32c(crc, sctx->send_buf + data_offset, block_len);

... and because of that you can't simply use send_cmd ;(

> +	hdr->crc = cpu_to_le32(crc);
> +
> +	ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
> +			&sctx->send_off);
> +	if (!ret) {
> +		ret = write_buf(sctx->send_filp, sctx->send_buf + data_offset,
> +				block_len, &sctx->send_off);
> +	}
> +	sctx->total_send_size += sctx->send_size + block_len;
> +	sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] +=
> +		sctx->send_size + block_len;
> +	sctx->send_size = 0;
> +
> +tlv_put_failure:
> +out:
> +	fs_path_free(p);
> +	iput(inode);
> +	return ret;
> +}
> +
> +static int send_extent_data(struct send_ctx *sctx, struct btrfs_path *path,
> +			    const u64 offset, const u64 len)

nit: Instead of sending around a btrfs_path struct around and
"polluting" callees to deal with the oddities of our btree interface i.e
btrfs_item_ptr et al. Why not refactor the code so that when we know we
are about to send an extent data simply initialize some struct
extent_info with all the necessary data items: extent type, compression
type, based on the extent type properly initialize a size attribute etc
and pass that. Right now you have send_extent_data fiddling with
path->nodes[0], then based on that you either call
send_encoded_inline_extent or send_encoded_extent, instead pass
extent_info to send_extent_data/clone_range and be done with it.


<snip>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes
  2021-09-01 17:01 ` [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes Omar Sandoval
@ 2021-10-18 12:44   ` Nikolay Borisov
  2021-10-18 18:34     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-18 12:44 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Now that the new support is implemented, allow the ioctl to accept the
> flags and update the version in sysfs.

This seems like an appropriate place to bring up the discussion about
versioned streams. SO instead of adding a BTRFS_SEND_FLAG_STREAM_V2
flag, which implies that for the next version we have to add
BTRFS_SEND_FLAG_STREAM_V3 etc. Why not generalize the flag to
BTRFS_SEND_FLAG_STREAM_VERSIONED and carve an u32 from one of the
reserved fields so that in the future we simply increment the version field?


> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
>  fs/btrfs/send.c            | 10 +++++++++-
>  fs/btrfs/send.h            |  2 +-
>  include/uapi/linux/btrfs.h |  4 +++-
>  3 files changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index 0ba8dc3a9f56..90ca915fed78 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -671,7 +671,10 @@ static int send_header(struct send_ctx *sctx)
>  	struct btrfs_stream_header hdr;
>  
>  	strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
> -	hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
> +	if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2)
> +		hdr.version = cpu_to_le32(2);
> +	else
> +		hdr.version = cpu_to_le32(1);
>  
>  	return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
>  					&sctx->send_off);
> @@ -7466,6 +7469,11 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
>  		ret = -EINVAL;
>  		goto out;
>  	}
> +	if ((arg->flags & BTRFS_SEND_FLAG_COMPRESSED) &&
> +	    !(arg->flags & BTRFS_SEND_FLAG_STREAM_V2)) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
>  
>  	sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL);
>  	if (!sctx) {
> diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
> index 9f4f7b96b1eb..9c83e14a43b2 100644
> --- a/fs/btrfs/send.h
> +++ b/fs/btrfs/send.h
> @@ -10,7 +10,7 @@
>  #include "ctree.h"
>  
>  #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
> -#define BTRFS_SEND_STREAM_VERSION 1
> +#define BTRFS_SEND_STREAM_VERSION 2
>  
>  /*
>   * In send stream v1, no command is larger than 64k. In send stream v2, no limit
> diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
> index 4f875f355e83..5c13e407982f 100644
> --- a/include/uapi/linux/btrfs.h
> +++ b/include/uapi/linux/btrfs.h
> @@ -787,7 +787,9 @@ struct btrfs_ioctl_received_subvol_args {
>  #define BTRFS_SEND_FLAG_MASK \
>  	(BTRFS_SEND_FLAG_NO_FILE_DATA | \
>  	 BTRFS_SEND_FLAG_OMIT_STREAM_HEADER | \
> -	 BTRFS_SEND_FLAG_OMIT_END_CMD)
> +	 BTRFS_SEND_FLAG_OMIT_END_CMD | \
> +	 BTRFS_SEND_FLAG_STREAM_V2 | \
> +	 BTRFS_SEND_FLAG_COMPRESSED)
>  
>  struct btrfs_ioctl_send_args {
>  	__s64 send_fd;			/* in */
> 

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 10/14] btrfs: add send stream v2 definitions
  2021-09-01 17:01 ` [PATCH v11 10/14] btrfs: add send stream v2 definitions Omar Sandoval
@ 2021-10-18 12:46   ` Nikolay Borisov
  2021-10-18 15:11   ` Nikolay Borisov
  1 sibling, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-18 12:46 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> This adds the definitions of the new commands for send stream version 2
> and their respective attributes: fallocate, FS_IOC_SETFLAGS (a.k.a.
> chattr), and encoded writes. It also documents two changes to the send
> stream format in v2: the receiver shouldn't assume a maximum command
> size, and the DATA attribute is encoded differently to allow for writes
> larger than 64k. These will be implemented in subsequent changes, and
> then the ioctl will accept the new flags.
> 
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>


^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 11/14] btrfs: send: write larger chunks when using stream v2
  2021-09-01 17:01 ` [PATCH v11 11/14] btrfs: send: write larger chunks when using stream v2 Omar Sandoval
@ 2021-10-18 12:57   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-18 12:57 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> The length field of the send stream TLV header is 16 bits. This means
> that the maximum amount of data that can be sent for one write is 64k
> minus one. However, encoded writes must be able to send the maximum
> compressed extent (128k) in one command. To support this, send stream
> version 2 encodes the DATA attribute differently: it has no length
> field, and the length is implicitly up to the end of containing command
> (which has a 32-bit length field). Although this is necessary for
> encoded writes, normal writes can benefit from it, too.
> 
> For v2, let's bump up the send buffer to the maximum compressed extent
> size plus 16k for the other metadata (144k total). Since this will most
> likely be vmalloc'd (and always will be after the next commit), we round
> it up to the next page since we might as well use the rest of the page
> on systems with >16k pages.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 10/14] btrfs: add send stream v2 definitions
  2021-09-01 17:01 ` [PATCH v11 10/14] btrfs: add send stream v2 definitions Omar Sandoval
  2021-10-18 12:46   ` Nikolay Borisov
@ 2021-10-18 15:11   ` Nikolay Borisov
  2021-10-18 18:58     ` Omar Sandoval
  1 sibling, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-18 15:11 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> This adds the definitions of the new commands for send stream version 2
> and their respective attributes: fallocate, FS_IOC_SETFLAGS (a.k.a.
> chattr), and encoded writes. It also documents two changes to the send
> stream format in v2: the receiver shouldn't assume a maximum command
> size, and the DATA attribute is encoded differently to allow for writes
> larger than 64k. These will be implemented in subsequent changes, and
> then the ioctl will accept the new flags.
> 
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
>  fs/btrfs/send.c            |  2 +-
>  fs/btrfs/send.h            | 30 +++++++++++++++++++++++++++++-
>  include/uapi/linux/btrfs.h | 13 +++++++++++++
>  3 files changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index afdcbe7844e0..2ec07943f173 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -7287,7 +7287,7 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
>  
>  	sctx->clone_roots_cnt = arg->clone_sources_count;
>  
> -	sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
> +	sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
>  	sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
>  	if (!sctx->send_buf) {
>  		ret = -ENOMEM;
> diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
> index de91488b7cd0..9f4f7b96b1eb 100644
> --- a/fs/btrfs/send.h
> +++ b/fs/btrfs/send.h
> @@ -12,7 +12,11 @@
>  #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
>  #define BTRFS_SEND_STREAM_VERSION 1
>  
> -#define BTRFS_SEND_BUF_SIZE SZ_64K
> +/*
> + * In send stream v1, no command is larger than 64k. In send stream v2, no limit
> + * should be assumed.
> + */
> +#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
>  
>  enum btrfs_tlv_type {
>  	BTRFS_TLV_U8,
> @@ -76,6 +80,13 @@ enum btrfs_send_cmd {
>  
>  	BTRFS_SEND_C_END,
>  	BTRFS_SEND_C_UPDATE_EXTENT,
> +
> +	/* The following commands were added in send stream v2. */
> +
> +	BTRFS_SEND_C_FALLOCATE,
> +	BTRFS_SEND_C_SETFLAGS,
> +	BTRFS_SEND_C_ENCODED_WRITE,
> +
>  	__BTRFS_SEND_C_MAX,
>  };
>  #define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
> @@ -106,6 +117,11 @@ enum {
>  	BTRFS_SEND_A_PATH_LINK,
>  
>  	BTRFS_SEND_A_FILE_OFFSET,
> +	/*
> +	 * In send stream v2, this attribute is special: it must be the last
> +	 * attribute in a command, its header contains only the type, and its
> +	 * length is implicitly the remaining length of the command.
> +	 */
>  	BTRFS_SEND_A_DATA,

Now that I think more about this, it would be best if this logic is
actually codified in the code. I.e first set of SEND_A_DATA would set
some bool/flag in the sctx and subsequent calls would be able to
ASSERT/WARN ?



^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio()
  2021-10-14 12:05   ` Nikolay Borisov
@ 2021-10-18 18:09     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-18 18:09 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Thu, Oct 14, 2021 at 03:05:54PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:00, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > btrfs_csum_one_bio() loops over each filesystem block in the bio while
> > keeping a cursor of its current logical position in the file in order to
> > look up the ordered extent to add the checksums to. However, this
> > doesn't make much sense for compressed extents, as a sector on disk does
> > not correspond to a sector of decompressed file data. It happens to work
> > because 1) the compressed bio always covers one ordered extent and 2)
> > the size of the bio is always less than the size of the ordered extent.
> > However, the second point will not always be true for encoded writes.
> > 
> > Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that
> > it can assume that the bio only covers one ordered extent. Since we're
> > already changing the signature, let's get rid of the contig parameter
> > and make it implied by the offset parameter, similar to the change we
> > recently made to btrfs_lookup_bio_sums(). Additionally, let's rename
> > nr_sectors to blockcount to make it clear that it's the number of
> > filesystem blocks, not the number of 512-byte sectors.
> > 
> > Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> 
> Code-wise this looks, though I don't know why we are guaranteed that a
> compressed extent will only cover a single OE.

See submit_compressed_extents(): we always add an ordered extent that
covers the whole range that we're submitting, and then
btrfs_submit_compressed_write() creates one or more bios that are
subsets of that range.

> But I trust you so:
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>

Thanks!

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls
  2021-10-15  9:42   ` Nikolay Borisov
@ 2021-10-18 18:16     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-18 18:16 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Fri, Oct 15, 2021 at 12:42:37PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > In order to allow sending and receiving compressed data without
> > decompressing it, we need an interface to write pre-compressed data
> > directly to the filesystem and the matching interface to read compressed
> > data without decompressing it. This adds the definitions for ioctls to
> > do that and detailed explanations of how to use them.
> > 
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> 
> One minor nit below but otherwise LGTM:
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> 
> <snip>
> 
> > +struct btrfs_ioctl_encoded_io_args {
> > +	/* Input parameters for both reads and writes. */
> > +
> > +	/*
> > +	 * iovecs containing encoded data.
> > +	 *
> > +	 * For reads, if the size of the encoded data is larger than the sum of
> > +	 * iov[n].iov_len for 0 <= n < iovcnt, then the ioctl fails with
> > +	 * ENOBUFS.
> > +	 *
> > +	 * For writes, the size of the encoded data is the sum of iov[n].iov_len
> > +	 * for 0 <= n < iovcnt. This must be less than 128 KiB (this limit may
> > +	 * increase in the future). This must also be less than or equal to
> > +	 * unencoded_len.
> > +	 */
> > +	const struct iovec __user *iov;
> > +	/* Number of iovecs. */
> > +	unsigned long iovcnt;
> > +	/*
> > +	 * Offset in file.
> > +	 *
> > +	 * For writes, must be aligned to the sector size of the filesystem.
> > +	 */
> > +	__s64 offset;
> > +	/* Currently must be zero. */
> > +	__u64 flags;
> > +
> 
> nit: A comment stating that the output params begin here could be added.

There is a comment in this spot:

	/*   
	 * For reads, the following members are filled in with the metadata for
	 * the encoded data.
	 * For writes, the following members must be set to the metadata for the
	 * encoded data.
	 */

I'll clarify it to:

        /*
	 * For reads, the following members are output parameters that will
	 * contain the returned metadata for the encoded data.
         * For writes, the following members must be set to the metadata for the
         * encoded data.
         */

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes
  2021-10-18 12:44   ` Nikolay Borisov
@ 2021-10-18 18:34     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-18 18:34 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Mon, Oct 18, 2021 at 03:44:23PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > Now that the new support is implemented, allow the ioctl to accept the
> > flags and update the version in sysfs.
> 
> This seems like an appropriate place to bring up the discussion about
> versioned streams. SO instead of adding a BTRFS_SEND_FLAG_STREAM_V2
> flag, which implies that for the next version we have to add
> BTRFS_SEND_FLAG_STREAM_V3 etc. Why not generalize the flag to
> BTRFS_SEND_FLAG_STREAM_VERSIONED and carve an u32 from one of the
> reserved fields so that in the future we simply increment the version field?

Yes, that definitely sounds better.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 10/14] btrfs: add send stream v2 definitions
  2021-10-18 15:11   ` Nikolay Borisov
@ 2021-10-18 18:58     ` Omar Sandoval
  2021-10-19  7:01       ` Nikolay Borisov
  0 siblings, 1 reply; 61+ messages in thread
From: Omar Sandoval @ 2021-10-18 18:58 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Mon, Oct 18, 2021 at 06:11:54PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > This adds the definitions of the new commands for send stream version 2
> > and their respective attributes: fallocate, FS_IOC_SETFLAGS (a.k.a.
> > chattr), and encoded writes. It also documents two changes to the send
> > stream format in v2: the receiver shouldn't assume a maximum command
> > size, and the DATA attribute is encoded differently to allow for writes
> > larger than 64k. These will be implemented in subsequent changes, and
> > then the ioctl will accept the new flags.
> > 
> > Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > ---
> >  fs/btrfs/send.c            |  2 +-
> >  fs/btrfs/send.h            | 30 +++++++++++++++++++++++++++++-
> >  include/uapi/linux/btrfs.h | 13 +++++++++++++
> >  3 files changed, 43 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> > index afdcbe7844e0..2ec07943f173 100644
> > --- a/fs/btrfs/send.c
> > +++ b/fs/btrfs/send.c
> > @@ -7287,7 +7287,7 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
> >  
> >  	sctx->clone_roots_cnt = arg->clone_sources_count;
> >  
> > -	sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
> > +	sctx->send_max_size = BTRFS_SEND_BUF_SIZE_V1;
> >  	sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
> >  	if (!sctx->send_buf) {
> >  		ret = -ENOMEM;
> > diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
> > index de91488b7cd0..9f4f7b96b1eb 100644
> > --- a/fs/btrfs/send.h
> > +++ b/fs/btrfs/send.h
> > @@ -12,7 +12,11 @@
> >  #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
> >  #define BTRFS_SEND_STREAM_VERSION 1
> >  
> > -#define BTRFS_SEND_BUF_SIZE SZ_64K
> > +/*
> > + * In send stream v1, no command is larger than 64k. In send stream v2, no limit
> > + * should be assumed.
> > + */
> > +#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
> >  
> >  enum btrfs_tlv_type {
> >  	BTRFS_TLV_U8,
> > @@ -76,6 +80,13 @@ enum btrfs_send_cmd {
> >  
> >  	BTRFS_SEND_C_END,
> >  	BTRFS_SEND_C_UPDATE_EXTENT,
> > +
> > +	/* The following commands were added in send stream v2. */
> > +
> > +	BTRFS_SEND_C_FALLOCATE,
> > +	BTRFS_SEND_C_SETFLAGS,
> > +	BTRFS_SEND_C_ENCODED_WRITE,
> > +
> >  	__BTRFS_SEND_C_MAX,
> >  };
> >  #define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
> > @@ -106,6 +117,11 @@ enum {
> >  	BTRFS_SEND_A_PATH_LINK,
> >  
> >  	BTRFS_SEND_A_FILE_OFFSET,
> > +	/*
> > +	 * In send stream v2, this attribute is special: it must be the last
> > +	 * attribute in a command, its header contains only the type, and its
> > +	 * length is implicitly the remaining length of the command.
> > +	 */
> >  	BTRFS_SEND_A_DATA,
> 
> Now that I think more about this, it would be best if this logic is
> actually codified in the code. I.e first set of SEND_A_DATA would set
> some bool/flag in the sctx and subsequent calls would be able to
> ASSERT/WARN ?

I suppose I could do something like this, is that what you had in mind?

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 90ca915fed78..46443d80b431 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -81,6 +81,7 @@ struct send_ctx {
 	char *send_buf;
 	u32 send_size;
 	u32 send_max_size;
+	bool put_data;
 	struct page **send_buf_pages;
 	u64 total_send_size;
 	u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
@@ -575,6 +576,9 @@ static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
 	int total_len = sizeof(*hdr) + len;
 	int left = sctx->send_max_size - sctx->send_size;
 
+	if (WARN_ON(sctx->put_data))
+		return -EINVAL;
+
 	if (unlikely(left < total_len))
 		return -EOVERFLOW;
 
@@ -718,6 +722,7 @@ static int send_cmd(struct send_ctx *sctx)
 	sctx->total_send_size += sctx->send_size;
 	sctx->cmd_send_size[get_unaligned_le16(&hdr->cmd)] += sctx->send_size;
 	sctx->send_size = 0;
+	sctx->put_data = false;
 
 	return ret;
 }
@@ -4913,6 +4918,9 @@ static inline u64 max_send_read_size(const struct send_ctx *sctx)
 
 static int put_data_header(struct send_ctx *sctx, u32 len)
 {
+	if (WARN_ON(sctx->put_data))
+		return -EINVAL;
+	sctx->put_data = true;
 	if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) {
 		/*
 		 * In v2, the data attribute header doesn't include a length; it
@@ -5368,6 +5376,7 @@ static int send_encoded_extent(struct send_ctx *sctx, struct btrfs_path *path,
 	sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] +=
 		sctx->send_size + block_len;
 	sctx->send_size = 0;
+	sctx->put_data = false;
 
 tlv_put_failure:
 out:

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ
  2021-10-15 11:45   ` Nikolay Borisov
@ 2021-10-18 23:59     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-18 23:59 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Fri, Oct 15, 2021 at 02:45:46PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > There are 4 main cases:
> > 
> > 1. Inline extents: we copy the data straight out of the extent buffer.
> > 2. Hole/preallocated extents: we fill in zeroes.
> > 3. Regular, uncompressed extents: we read the sectors we need directly
> >    from disk.
> > 4. Regular, compressed extents: we read the entire compressed extent
> >    from disk and indicate what subset of the decompressed extent is in
> >    the file.
> > 
> > This initial implementation simplifies a few things that can be improved
> > in the future:
> > 
> > - We hold the inode lock during the operation.
> > - Cases 1, 3, and 4 allocate temporary memory to read into before
> >   copying out to userspace.
> > - We don't do read repair, because it turns out that read repair is
> >   currently broken for compressed data.
> > 
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > ---
> >  fs/btrfs/ctree.h |   4 +
> >  fs/btrfs/inode.c | 489 +++++++++++++++++++++++++++++++++++++++++++++++
> >  fs/btrfs/ioctl.c | 111 +++++++++++
> >  3 files changed, 604 insertions(+)
> > 
> > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> > index b95ec5fb68d5..cbd7e07c1c34 100644
> > --- a/fs/btrfs/ctree.h
> > +++ b/fs/btrfs/ctree.h
> > @@ -3223,6 +3223,10 @@ int btrfs_writepage_cow_fixup(struct page *page);
> >  void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode,
> >  					  struct page *page, u64 start,
> >  					  u64 end, bool uptodate);
> > +struct btrfs_ioctl_encoded_io_args;
> > +ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
> > +			   struct btrfs_ioctl_encoded_io_args *encoded);
> > +
> >  extern const struct dentry_operations btrfs_dentry_operations;
> >  extern const struct iomap_ops btrfs_dio_iomap_ops;
> >  extern const struct iomap_dio_ops btrfs_dio_ops;
> > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> > index a87a34f56234..1940f22179ba 100644
> > --- a/fs/btrfs/inode.c
> > +++ b/fs/btrfs/inode.c
> > @@ -10500,6 +10500,495 @@ void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end)
> >  	}
> >  }
> >  
> 
> <snip>
> 
> > +
> > +static blk_status_t btrfs_encoded_read_check_bio(struct btrfs_io_bio *io_bio)
> 
> nit: The gist of this function is to check the csum so how about
> renaming it to btrfs_encoded_read_verify_csum

Good point, will do.

> > +
> > +static void btrfs_encoded_read_endio(struct bio *bio)
> > +{
> > +	struct btrfs_encoded_read_private *priv = bio->bi_private;
> > +	struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
> > +	blk_status_t status;
> > +
> > +	status = btrfs_encoded_read_check_bio(io_bio);
> > +	if (status) {
> > +		/*
> > +		 * The memory barrier implied by the atomic_dec_return() here
> > +		 * pairs with the memory barrier implied by the
> > +		 * atomic_dec_return() or io_wait_event() in
> 
> nit: I think atomic_dec_return in read_regular_fill_pages is
> inconsequential, what we want to ensure is that when the caller of
> io_wait_event is woken up by this thread it will observe the
> priv->status, which it will, because the atomic-dec_return in this
> function has paired with the general barrier interpolated by wait_event.
> 
> So for brevity just leave the text to say "by io_wait_event".

Considering that there is a code path in
btrfs_encoded_read_regular_fill_pages() where atomic_dec_return() is
called but io_wait_event() isn't, I think it's important to mention
both. (This path should be fairly rare, since it can only happen if all
of the bios are completed before the submitting thread checks the
pending counter. But, it's a possible code path, and I wouldn't want
someone reading the comment to be confused and think that we're missing
a barrier in that case.)

> > +		 * btrfs_encoded_read_regular_fill_pages() to ensure that this
> > +		 * write is observed before the load of status in
> > +		 * btrfs_encoded_read_regular_fill_pages().
> > +		 */
> > +		WRITE_ONCE(priv->status, status);
> > +	}
> > +	if (!atomic_dec_return(&priv->pending))
> > +		wake_up(&priv->wait);
> > +	btrfs_io_bio_free_csum(io_bio);
> > +	bio_put(bio);
> > +}
> 
> <snip>
> 
> > @@ -4824,6 +4841,94 @@ static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
> >  	return ret;
> >  }
> >  
> 
> <snip>
> 
> > +	memset((char *)&args + copy_end_kernel, 0,
> > +	       sizeof(args) - copy_end_kernel);
> 
> nit: This memset can be eliminated ( in source) by marking args = {};
> and just leaving copy from user above.

args = {} results in slightly worse generated code, but that doesn't
really matter here, so I'll change it.

> > +
> > +	ret = import_iovec(READ, args.iov, args.iovcnt, ARRAY_SIZE(iovstack),
> > +			   &iov, &iter);
> > +	if (ret < 0)
> > +		goto out_acct;
> > +
> > +	if (iov_iter_count(&iter) == 0) {
> > +		ret = 0;
> > +		goto out_iov;
> > +	}
> > +	pos = args.offset;
> > +	ret = rw_verify_area(READ, file, &pos, args.len);
> > +	if (ret < 0)
> > +		goto out_iov;
> > +
> > +	init_sync_kiocb(&kiocb, file);
> > +	ret = kiocb_set_rw_flags(&kiocb, 0);
> 
> This call is a noop due to:
> 	if (!flags)
> 		return 0;
> 
> in kiocb_set_rw_flags.

Good catch, I'll remove that call.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes
  2021-10-18 11:59   ` Nikolay Borisov
@ 2021-10-19  0:11     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-19  0:11 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Mon, Oct 18, 2021 at 02:59:08PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > Now that all of the pieces are in place, we can use the ENCODED_WRITE
> > command to send compressed extents when appropriate.
> > 
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> 
> Overall looks sane but consider some of the nits below.
> 
> 
> <snip>
> 
> > +static int send_encoded_extent(struct send_ctx *sctx, struct btrfs_path *path,
> > +			       u64 offset, u64 len)
> > +{
> > +	struct btrfs_root *root = sctx->send_root;
> > +	struct btrfs_fs_info *fs_info = root->fs_info;
> > +	struct inode *inode;
> > +	struct fs_path *p;
> > +	struct extent_buffer *leaf = path->nodes[0];
> > +	struct btrfs_key key;
> > +	struct btrfs_file_extent_item *ei;
> > +	u64 block_start;
> > +	u64 block_len;
> > +	u32 data_offset;
> > +	struct btrfs_cmd_header *hdr;
> > +	u32 crc;
> > +	int ret;
> > +
> > +	inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root);
> > +	if (IS_ERR(inode))
> > +		return PTR_ERR(inode);
> > +
> > +	p = fs_path_alloc();
> > +	if (!p) {
> > +		ret = -ENOMEM;
> > +		goto out;
> > +	}
> > +
> > +	ret = begin_cmd(sctx, BTRFS_SEND_C_ENCODED_WRITE);
> > +	if (ret < 0)
> > +		goto out;
> > +
> > +	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
> > +	if (ret < 0)
> > +		goto out;
> > +
> > +	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
> > +	ei = btrfs_item_ptr(leaf, path->slots[0],
> > +			    struct btrfs_file_extent_item);
> > +	block_start = btrfs_file_extent_disk_bytenr(leaf, ei);
> 
> block_start is somewhat ambiguous here, this is just the disk bytenr of
> the extent.
> 
> > +	block_len = btrfs_file_extent_disk_num_bytes(leaf, ei);
> 
> Why is this called block_len when it's just the size in bytes on-disk?

I copied this naming from extent_map since btrfs_encoded_read() was the
reference for this code, but I'll change the naming here.

> > +
> > +	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
> > +	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
> > +	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_FILE_LEN,
> > +		    min(key.offset + btrfs_file_extent_num_bytes(leaf, ei) - offset,
> > +			len));
> > +	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_LEN,
> > +		    btrfs_file_extent_ram_bytes(leaf, ei));
> > +	TLV_PUT_U64(sctx, BTRFS_SEND_A_UNENCODED_OFFSET,
> > +		    offset - key.offset + btrfs_file_extent_offset(leaf, ei));
> > +	ret = btrfs_encoded_io_compression_from_extent(
> > +				btrfs_file_extent_compression(leaf, ei));
> > +	if (ret < 0)
> > +		goto out;
> > +	TLV_PUT_U32(sctx, BTRFS_SEND_A_COMPRESSION, ret);
> > +	TLV_PUT_U32(sctx, BTRFS_SEND_A_ENCRYPTION, 0);
> > +
> > +	ret = put_data_header(sctx, block_len);
> > +	if (ret < 0)
> > +		goto out;
> > +
> > +	data_offset = ALIGN(sctx->send_size, PAGE_SIZE);
> 
> nit: The whole data_offset warrants a comment here, since send_buf is
> now mapped from send_buf_pages, so all the TLV you've put before are
> actually stored in the beginning of send_buf_pages, so by doing the
> above you ensure the data write begins on a clean page boundary ...

Yup, I'll add a comment.

> > +	if (data_offset > sctx->send_max_size ||
> > +	    sctx->send_max_size - data_offset < block_len) {
> > +		ret = -EOVERFLOW;
> > +		goto out;
> > +	}
> > +
> > +	ret = btrfs_encoded_read_regular_fill_pages(inode, block_start,
> > +						    block_len,
> > +						    sctx->send_buf_pages +
> > +						    (data_offset >> PAGE_SHIFT));
> > +	if (ret)
> > +		goto out;
> > +
> > +	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
> > +	hdr->len = cpu_to_le32(sctx->send_size + block_len - sizeof(*hdr));
> > +	hdr->crc = 0;
> > +	crc = btrfs_crc32c(0, sctx->send_buf, sctx->send_size);
> > +	crc = btrfs_crc32c(crc, sctx->send_buf + data_offset, block_len);
> 
> ... and because of that you can't simply use send_cmd ;(
> 
> > +	hdr->crc = cpu_to_le32(crc);
> > +
> > +	ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
> > +			&sctx->send_off);
> > +	if (!ret) {
> > +		ret = write_buf(sctx->send_filp, sctx->send_buf + data_offset,
> > +				block_len, &sctx->send_off);
> > +	}
> > +	sctx->total_send_size += sctx->send_size + block_len;
> > +	sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] +=
> > +		sctx->send_size + block_len;
> > +	sctx->send_size = 0;
> > +
> > +tlv_put_failure:
> > +out:
> > +	fs_path_free(p);
> > +	iput(inode);
> > +	return ret;
> > +}
> > +
> > +static int send_extent_data(struct send_ctx *sctx, struct btrfs_path *path,
> > +			    const u64 offset, const u64 len)
> 
> nit: Instead of sending around a btrfs_path struct around and
> "polluting" callees to deal with the oddities of our btree interface i.e
> btrfs_item_ptr et al. Why not refactor the code so that when we know we
> are about to send an extent data simply initialize some struct
> extent_info with all the necessary data items: extent type, compression
> type, based on the extent type properly initialize a size attribute etc
> and pass that. Right now you have send_extent_data fiddling with
> path->nodes[0], then based on that you either call
> send_encoded_inline_extent or send_encoded_extent, instead pass
> extent_info to send_extent_data/clone_range and be done with it.

I don't like this for a few reasons:

* An extra "struct extent_info" layer of abstraction would just be extra
  cognitive overhead. I hate having to trace back where the fields in
  some struct came from when it's information that's readily available
  in more well-known data structures.
* send_encoded_inline_extent() (called by send_extent_data()) needs the
  btrfs_path in order to get the inline data anyways.
* clone_range() also already deals with btrfs_paths, so it's not new.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 10/14] btrfs: add send stream v2 definitions
  2021-10-18 18:58     ` Omar Sandoval
@ 2021-10-19  7:01       ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-19  7:01 UTC (permalink / raw)
  To: Omar Sandoval; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api



On 18.10.21 г. 21:58, Omar Sandoval wrote:
> I suppose I could do something like this, is that what you had in mind?


Yes, however I think it needs to be augmented a bit like making this
member populated/checked only if V2 is being used? But that's generally
what I had in mind.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len
  2021-09-01 17:01 ` [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len Omar Sandoval
@ 2021-10-20 13:49   ` Nikolay Borisov
  2021-10-20 18:48     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-20 13:49 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <borisb@fb.com>
> 
> An encoded extent can be up to 128K in length, which exceeds the largest
> value expressible by the current send stream format's 16 bit tlv_len
> field. Since encoded writes cannot be split into multiple writes by
> btrfs send, the send stream format must change to accommodate encoded
> writes.
> 
> Supporting this changed format requires retooling how we store the
> commands we have processed. Since we can no longer use btrfs_tlv_header
> to describe every attribute, we define a new struct btrfs_send_attribute
> which has a 32 bit length field, and use that to store the attribute
> information needed for receive processing. This is transparent to users
> of the various TLV_GET macros.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  common/send-stream.c | 34 +++++++++++++++++++++++++---------
>  1 file changed, 25 insertions(+), 9 deletions(-)
> 
> diff --git a/common/send-stream.c b/common/send-stream.c
> index a0c52f79..cd5aa311 100644
> --- a/common/send-stream.c
> +++ b/common/send-stream.c
> @@ -24,13 +24,23 @@
>  #include "crypto/crc32c.h"
>  #include "common/utils.h"
>  
> +struct btrfs_send_attribute {
> +	u16 tlv_type;
> +	/*
> +	 * Note: in btrfs_tlv_header, this is __le16, but we need 32 bits for
> +	 * attributes with file data as of version 2 of the send stream format
> +	 */
> +	u32 tlv_len;
> +	char *data;
> +};
> +
>  struct btrfs_send_stream {
>  	char read_buf[BTRFS_SEND_BUF_SIZE];
>  	int fd;
>  
>  	int cmd;
>  	struct btrfs_cmd_header *cmd_hdr;
> -	struct btrfs_tlv_header *cmd_attrs[BTRFS_SEND_A_MAX + 1];
> +	struct btrfs_send_attribute cmd_attrs[BTRFS_SEND_A_MAX + 1];

This is subtle and it took me a couple of minutes to get it at first.
Currently cmds_attrs holds an array of pointers into the command buffer,
with every pointer being the beginning of the tlv_header, whilst with
your change cmd_attr now holds actual btrfs_send_attribute structures
(52 bytes vs sizeof(uintptr_t)  bytes before). So this increases the
overall size of btrfs_send_stream because with  your version of the code
you parse the type/length fields and store them directly in the send
attribute structure at command parse time rather than just referring to
the raw command buffer during read_cmd and referring to them during
attribute parsing.

This might seem superficial but this kind of change should really be
mentioned explicitly in the changelog to better prepare reviewers what
to expect.


OTOH the code LGTM and actually now it seems less tricky than before so:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>


David if you deem it necessary adjust the commit message appropriately.



^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf
  2021-09-01 17:01 ` [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf Omar Sandoval
@ 2021-10-20 14:09   ` Nikolay Borisov
  2021-10-20 14:35     ` Nikolay Borisov
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-20 14:09 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <boris@bur.io>
> 
> In send stream v2, write commands can now be an arbitrary size. For that
> reason, we can no longer allocate a fixed array in sctx for read_cmd.
> Instead, read_cmd dynamically allocates sctx->read_buf. To avoid
> needless reallocations, we reuse read_buf between read_cmd calls by also
> keeping track of the size of the allocated buffer in sctx->read_buf_sz.
> 
> We do the first allocation of the old default size at the start of
> processing the stream, and we only reallocate if we encounter a command
> that needs a larger buffer.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  common/send-stream.c | 55 ++++++++++++++++++++++++++++----------------
>  send.h               |  2 +-
>  2 files changed, 36 insertions(+), 21 deletions(-)
> 

<snip>

> @@ -124,18 +125,22 @@ static int read_cmd(struct btrfs_send_stream *sctx)
>  		goto out;
>  	}
>  
> -	sctx->cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
> -	cmd = le16_to_cpu(sctx->cmd_hdr->cmd);
> -	cmd_len = le32_to_cpu(sctx->cmd_hdr->len);
> -
> -	if (cmd_len + sizeof(*sctx->cmd_hdr) >= sizeof(sctx->read_buf)) {
> -		ret = -EINVAL;
> -		error("command length %u too big for buffer %zu",
> -				cmd_len, sizeof(sctx->read_buf));
> -		goto out;
> +	cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
> +	cmd_len = le32_to_cpu(cmd_hdr->len);
> +	cmd = le16_to_cpu(cmd_hdr->cmd);
> +	buf_len = sizeof(*cmd_hdr) + cmd_len;
> +	if (sctx->read_buf_sz < buf_len) {
> +		sctx->read_buf = realloc(sctx->read_buf, buf_len);
> +		if (!sctx->read_buf) {

nit: This is prone to a memory leak, because according to
https://en.cppreference.com/w/c/memory/realloc

If there is not enough memory, the old memory block is not freed and
null pointer is returned.


This means if realloc fails it will overwrite sctx->read_buf with NULL,
yet the old memory won't be freed which will cause a memory leak. It can
be argued that's not critical since we'll very quickly terminate the
program afterwards but still.


<snip>


^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf
  2021-10-20 14:09   ` Nikolay Borisov
@ 2021-10-20 14:35     ` Nikolay Borisov
  2021-10-20 17:44       ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-20 14:35 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 20.10.21 г. 17:09, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
>> From: Boris Burkov <boris@bur.io>
>>
>> In send stream v2, write commands can now be an arbitrary size. For that

nit: Actually can't commands really be up-to BTRFS_MAX_COMPRESSED + 16K
really  or are we going to leave this as an implementation detail? I'm
fine either way but looking at the changelog of patch 12 in the kernel
series doesn't really mention of arbitrary size, instead it explicitly
is talking about sending the max compressed extent size (128K) + some
space for metadata (the 16K above).

>> reason, we can no longer allocate a fixed array in sctx for read_cmd.
>> Instead, read_cmd dynamically allocates sctx->read_buf. To avoid
>> needless reallocations, we reuse read_buf between read_cmd calls by also
>> keeping track of the size of the allocated buffer in sctx->read_buf_sz.
>>
>> We do the first allocation of the old default size at the start of
>> processing the stream, and we only reallocate if we encounter a command
>> that needs a larger buffer.
>>
>> Signed-off-by: Boris Burkov <boris@bur.io>
>> ---
>>  common/send-stream.c | 55 ++++++++++++++++++++++++++++----------------
>>  send.h               |  2 +-
>>  2 files changed, 36 insertions(+), 21 deletions(-)
>>
> 
> <snip>
> 
>> @@ -124,18 +125,22 @@ static int read_cmd(struct btrfs_send_stream *sctx)
>>  		goto out;
>>  	}
>>  
>> -	sctx->cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
>> -	cmd = le16_to_cpu(sctx->cmd_hdr->cmd);
>> -	cmd_len = le32_to_cpu(sctx->cmd_hdr->len);
>> -
>> -	if (cmd_len + sizeof(*sctx->cmd_hdr) >= sizeof(sctx->read_buf)) {
>> -		ret = -EINVAL;
>> -		error("command length %u too big for buffer %zu",
>> -				cmd_len, sizeof(sctx->read_buf));
>> -		goto out;
>> +	cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
>> +	cmd_len = le32_to_cpu(cmd_hdr->len);
>> +	cmd = le16_to_cpu(cmd_hdr->cmd);
>> +	buf_len = sizeof(*cmd_hdr) + cmd_len;
>> +	if (sctx->read_buf_sz < buf_len) {
>> +		sctx->read_buf = realloc(sctx->read_buf, buf_len);
>> +		if (!sctx->read_buf) {
> 
> nit: This is prone to a memory leak, because according to
> https://en.cppreference.com/w/c/memory/realloc
> 
> If there is not enough memory, the old memory block is not freed and
> null pointer is returned.
> 
> 
> This means if realloc fails it will overwrite sctx->read_buf with NULL,
> yet the old memory won't be freed which will cause a memory leak. It can
> be argued that's not critical since we'll very quickly terminate the
> program afterwards but still.
> 
> 
> <snip>
> 

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 03/10] btrfs-progs: receive: support v2 send stream DATA tlv format
  2021-09-01 17:01 ` [PATCH v11 03/10] btrfs-progs: receive: support v2 send stream DATA tlv format Omar Sandoval
@ 2021-10-20 14:36   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-20 14:36 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <borisb@fb.com>
> 
> The new format privileges the BTRFS_SEND_A_DATA attribute by
> guaranteeing it will always be the last attribute in any command that
> needs it, and by implicitly encoding the data length as the difference
> between the total command length in the command header and the sizes of
> the rest of the attributes (and of course the tlv_type identifying the
> DATA attribute). To parse the new stream, we must read the tlv_type and
> if it is not DATA, we proceed normally, but if it is DATA, we don't
> parse a tlv_len but simply compute the length.
> 
> In addition, we add some bounds checking when parsing each chunk of
> data, as well as for the tlv_len itself.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 04/10] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h
  2021-09-01 17:01 ` [PATCH v11 04/10] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h Omar Sandoval
@ 2021-10-20 14:38   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-20 14:38 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <boris@bur.io>
> 
> Send stream v2 adds three commands and several attributes associated to
> those commands. Before we implement processing them, add all the
> commands and attributes. This avoids leaving the enums in an
> intermediate state that doesn't correspond to any version of send
> stream.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf
  2021-10-20 14:35     ` Nikolay Borisov
@ 2021-10-20 17:44       ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-20 17:44 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Wed, Oct 20, 2021 at 05:35:42PM +0300, Nikolay Borisov wrote:
> 
> 
> On 20.10.21 г. 17:09, Nikolay Borisov wrote:
> > 
> > 
> > On 1.09.21 г. 20:01, Omar Sandoval wrote:
> >> From: Boris Burkov <boris@bur.io>
> >>
> >> In send stream v2, write commands can now be an arbitrary size. For that
> 
> nit: Actually can't commands really be up-to BTRFS_MAX_COMPRESSED + 16K
> really  or are we going to leave this as an implementation detail? I'm
> fine either way but looking at the changelog of patch 12 in the kernel
> series doesn't really mention of arbitrary size, instead it explicitly
> is talking about sending the max compressed extent size (128K) + some
> space for metadata (the 16K above).

Patch 10 mentions it in the changelog: "It also documents two changes to the
send stream format in v2: the receiver shouldn't assume a maximum command size,
and the DATA attribute is encoded differently to allow for writes larger than
64k".

And in send.h:

-#define BTRFS_SEND_BUF_SIZE SZ_64K
+/*
+ * In send stream v1, no command is larger than 64k. In send stream v2, no limit
+ * should be assumed.
+ */
+#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K

You're correct that right now the limit is BTRFS_MAX_COMPRESSED + 16k,
but I think it's better if userspace doesn't make any assumptions about
that in case we want to send larger commands in the future.

> >> reason, we can no longer allocate a fixed array in sctx for read_cmd.
> >> Instead, read_cmd dynamically allocates sctx->read_buf. To avoid
> >> needless reallocations, we reuse read_buf between read_cmd calls by also
> >> keeping track of the size of the allocated buffer in sctx->read_buf_sz.
> >>
> >> We do the first allocation of the old default size at the start of
> >> processing the stream, and we only reallocate if we encounter a command
> >> that needs a larger buffer.
> >>
> >> Signed-off-by: Boris Burkov <boris@bur.io>
> >> ---
> >>  common/send-stream.c | 55 ++++++++++++++++++++++++++++----------------
> >>  send.h               |  2 +-
> >>  2 files changed, 36 insertions(+), 21 deletions(-)
> >>
> > 
> > <snip>
> > 
> >> @@ -124,18 +125,22 @@ static int read_cmd(struct btrfs_send_stream *sctx)
> >>  		goto out;
> >>  	}
> >>  
> >> -	sctx->cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
> >> -	cmd = le16_to_cpu(sctx->cmd_hdr->cmd);
> >> -	cmd_len = le32_to_cpu(sctx->cmd_hdr->len);
> >> -
> >> -	if (cmd_len + sizeof(*sctx->cmd_hdr) >= sizeof(sctx->read_buf)) {
> >> -		ret = -EINVAL;
> >> -		error("command length %u too big for buffer %zu",
> >> -				cmd_len, sizeof(sctx->read_buf));
> >> -		goto out;
> >> +	cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
> >> +	cmd_len = le32_to_cpu(cmd_hdr->len);
> >> +	cmd = le16_to_cpu(cmd_hdr->cmd);
> >> +	buf_len = sizeof(*cmd_hdr) + cmd_len;
> >> +	if (sctx->read_buf_sz < buf_len) {
> >> +		sctx->read_buf = realloc(sctx->read_buf, buf_len);
> >> +		if (!sctx->read_buf) {
> > 
> > nit: This is prone to a memory leak, because according to
> > https://en.cppreference.com/w/c/memory/realloc
> > 
> > If there is not enough memory, the old memory block is not freed and
> > null pointer is returned.
> > 
> > 
> > This means if realloc fails it will overwrite sctx->read_buf with NULL,
> > yet the old memory won't be freed which will cause a memory leak. It can
> > be argued that's not critical since we'll very quickly terminate the
> > program afterwards but still.

Good catch, I'll fix that.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len
  2021-10-20 13:49   ` Nikolay Borisov
@ 2021-10-20 18:48     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-20 18:48 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Wed, Oct 20, 2021 at 04:49:38PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Boris Burkov <borisb@fb.com>
> > 
> > An encoded extent can be up to 128K in length, which exceeds the largest
> > value expressible by the current send stream format's 16 bit tlv_len
> > field. Since encoded writes cannot be split into multiple writes by
> > btrfs send, the send stream format must change to accommodate encoded
> > writes.
> > 
> > Supporting this changed format requires retooling how we store the
> > commands we have processed. Since we can no longer use btrfs_tlv_header
> > to describe every attribute, we define a new struct btrfs_send_attribute
> > which has a 32 bit length field, and use that to store the attribute
> > information needed for receive processing. This is transparent to users
> > of the various TLV_GET macros.
> > 
> > Signed-off-by: Boris Burkov <boris@bur.io>
> > ---
> >  common/send-stream.c | 34 +++++++++++++++++++++++++---------
> >  1 file changed, 25 insertions(+), 9 deletions(-)
> > 
> > diff --git a/common/send-stream.c b/common/send-stream.c
> > index a0c52f79..cd5aa311 100644
> > --- a/common/send-stream.c
> > +++ b/common/send-stream.c
> > @@ -24,13 +24,23 @@
> >  #include "crypto/crc32c.h"
> >  #include "common/utils.h"
> >  
> > +struct btrfs_send_attribute {
> > +	u16 tlv_type;
> > +	/*
> > +	 * Note: in btrfs_tlv_header, this is __le16, but we need 32 bits for
> > +	 * attributes with file data as of version 2 of the send stream format
> > +	 */
> > +	u32 tlv_len;
> > +	char *data;
> > +};
> > +
> >  struct btrfs_send_stream {
> >  	char read_buf[BTRFS_SEND_BUF_SIZE];
> >  	int fd;
> >  
> >  	int cmd;
> >  	struct btrfs_cmd_header *cmd_hdr;
> > -	struct btrfs_tlv_header *cmd_attrs[BTRFS_SEND_A_MAX + 1];
> > +	struct btrfs_send_attribute cmd_attrs[BTRFS_SEND_A_MAX + 1];
> 
> This is subtle and it took me a couple of minutes to get it at first.
> Currently cmds_attrs holds an array of pointers into the command buffer,
> with every pointer being the beginning of the tlv_header, whilst with
> your change cmd_attr now holds actual btrfs_send_attribute structures
> (52 bytes vs sizeof(uintptr_t)  bytes before). So this increases the
> overall size of btrfs_send_stream because with  your version of the code
> you parse the type/length fields and store them directly in the send
> attribute structure at command parse time rather than just referring to
> the raw command buffer during read_cmd and referring to them during
> attribute parsing.
> 
> This might seem superficial but this kind of change should really be
> mentioned explicitly in the changelog to better prepare reviewers what
> to expect.
> 
> 
> OTOH the code LGTM and actually now it seems less tricky than before so:
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> 
> 
> David if you deem it necessary adjust the commit message appropriately.

I clarified the second paragraph to:

Supporting this changed format requires retooling how we store the
commands we have processed. We currently store pointers to the struct
btrfs_tlv_headers in the command buffer. This is not sufficient to
represent the new BTRFS_SEND_A_DATA format. Instead, parse the attribute
headers and store them in a new struct btrfs_send_attribute which has a
32-bit length field. This is transparent to users of the various TLV_GET
macros.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent
  2021-09-01 17:00 ` [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent Omar Sandoval
@ 2021-10-21 12:44   ` Nikolay Borisov
  2021-10-21 16:55     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-21 12:44 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:00, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Currently, we only create ordered extents when ram_bytes == num_bytes
> and offset == 0. However, RWF_ENCODED writes may create extents which

Change RWF_ENCODED to simply encoded as we no longer rely on RWF flags,
same thing for the changelog in the next patch.

<snip>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands
  2021-09-01 17:01 ` [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands Omar Sandoval
@ 2021-10-21 13:33   ` Nikolay Borisov
  2021-10-21 16:52     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-21 13:33 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <borisb@fb.com>
> 
<snip>

> +/* Data is not compressed. */
> +#define BTRFS_ENCODED_IO_COMPRESSION_NONE 0
> +/* Data is compressed as a single zlib stream. */
> +#define BTRFS_ENCODED_IO_COMPRESSION_ZLIB 1
> +/*
> + * Data is compressed as a single zstd frame with the windowLog compression
> + * parameter set to no more than 17.
> + */
> +#define BTRFS_ENCODED_IO_COMPRESSION_ZSTD 2
> +/*
> + * Data is compressed page by page (using the page size indicated by the name of
> + * the constant) with LZO1X and wrapped in the format documented in
> + * fs/btrfs/lzo.c. For writes, the compression page size must match the
> + * filesystem page size.
> + */
> +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_4K 3
> +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_8K 4
> +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_16K 5
> +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_32K 6
> +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_64K 7
> +#define BTRFS_ENCODED_IO_COMPRESSION_TYPES 8

nit: Make those an enum ? Same applies for the kernel counterpart patch.

> +
> +/* Data is not encrypted. */
> +#define BTRFS_ENCODED_IO_ENCRYPTION_NONE 0
> +#define BTRFS_ENCODED_IO_ENCRYPTION_TYPES 1
> +
>  /* Error codes as returned by the kernel */
>  enum btrfs_err_code {
>  	notused,
> @@ -949,6 +1077,10 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code)
>  				struct btrfs_ioctl_ino_lookup_user_args)
>  #define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \
>  				   struct btrfs_ioctl_vol_args_v2)
> +#define BTRFS_IOC_ENCODED_READ _IOR(BTRFS_IOCTL_MAGIC, 64, \
> +				    struct btrfs_ioctl_encoded_io_args)
> +#define BTRFS_IOC_ENCODED_WRITE _IOW(BTRFS_IOCTL_MAGIC, 64, \
> +				     struct btrfs_ioctl_encoded_io_args)
>  
>  #ifdef __cplusplus
>  }
> 

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write
  2021-09-01 17:01 ` [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write Omar Sandoval
@ 2021-10-21 13:55   ` Nikolay Borisov
  2021-10-21 17:22     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-21 13:55 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <boris@bur.io>
> 

<snip>

> @@ -79,6 +83,12 @@ struct btrfs_receive
>  	struct subvol_uuid_search sus;
>  
>  	int honor_end_cmd;
> +
> +	int force_decompress;

Make it bool

> +
> +	/* Reuse stream objects for encoded_write decompression fallback */
> +	ZSTD_DStream *zstd_dstream;
> +	z_stream *zlib_stream;
>  };
>  
>  static int finish_subvol(struct btrfs_receive *rctx)
> @@ -989,9 +999,222 @@ static int process_update_extent(const char *path, u64 offset, u64 len,
>  	return 0;
>  }
>  

<snip>

> +
> +static int decompress_lzo(const char *encoded_data, u64 encoded_len,
> +			  char *unencoded_data, u64 unencoded_len,
> +			  unsigned int page_size)
> +{
> +	uint32_t total_len;
> +	size_t in_pos, out_pos;
> +
> +	if (encoded_len < 4) {
> +		error("lzo header is truncated");
> +		return -EIO;
> +	}
> +	memcpy(&total_len, encoded_data, 4);
> +	total_len = le32toh(total_len);
> +	if (total_len > encoded_len) {
> +		error("lzo header is invalid");
> +		return -EIO;
> +	}
> +
> +	in_pos = 4;
> +	out_pos = 0;
> +	while (in_pos < total_len && out_pos < unencoded_len) {
> +		size_t page_remaining;
> +		uint32_t src_len;
> +		lzo_uint dst_len;
> +		int ret;
> +
> +		page_remaining = -in_pos % page_size;

Why the -in_pos?

> +		if (page_remaining < 4) {
> +			if (total_len - in_pos <= page_remaining)
> +				break;
> +			in_pos += page_remaining;
> +		}
> +
> +		if (total_len - in_pos < 4) {
> +			error("lzo segment header is truncated");
> +			return -EIO;
> +		}
> +
> +		memcpy(&src_len, encoded_data + in_pos, 4);
> +		src_len = le32toh(src_len);
> +		in_pos += 4;
> +		if (src_len > total_len - in_pos) {
> +			error("lzo segment header is invalid");
> +			return -EIO;
> +		}
> +
> +		dst_len = page_size;
> +		ret = lzo1x_decompress_safe((void *)(encoded_data + in_pos),
> +					    src_len,
> +					    (void *)(unencoded_data + out_pos),
> +					    &dst_len, NULL);
> +		if (ret != LZO_E_OK) {
> +			error("lzo1x_decompress_safe failed: %d", ret);
> +			return -EIO;
> +		}
> +
> +		in_pos += src_len;
> +		out_pos += dst_len;
> +	}
> +	return 0;
> +}
> +
> +static int decompress_and_write(struct btrfs_receive *rctx,
> +				const char *encoded_data, u64 offset,
> +				u64 encoded_len, u64 unencoded_file_len,
> +				u64 unencoded_len, u64 unencoded_offset,
> +				u32 compression)
> +{
> +	int ret = 0;
> +	size_t pos;
> +	ssize_t w;
> +	char *unencoded_data;
> +	int page_shift;
> +
> +	unencoded_data = calloc(unencoded_len, 1);
> +	if (!unencoded_data) {
> +		error("allocating space for unencoded data failed: %m");
> +		return -errno;
> +	}
> +
> +	switch (compression) {
> +	case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
> +		ret = decompress_zlib(rctx, encoded_data, encoded_len,
> +				      unencoded_data, unencoded_len);
> +		if (ret)
> +			goto out;
> +		break;
> +	case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
> +		ret = decompress_zstd(rctx, encoded_data, encoded_len,
> +				      unencoded_data, unencoded_len);
> +		if (ret)
> +			goto out;
> +		break;
> +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
> +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
> +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
> +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
> +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
> +		page_shift = compression - BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12;

Doesn't this calculation assume page size is 4k, what about arches with
larger page size (ppc/aarch64), shouldn't that '12' be adjusted?

> +		ret = decompress_lzo(encoded_data, encoded_len, unencoded_data,
> +				     unencoded_len, 1U << page_shift);
> +		if (ret)
> +			goto out;
> +		break;
> +	default:
> +		error("unknown compression: %d", compression);
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}
> +
> +	pos = unencoded_offset;
> +	while (pos < unencoded_file_len) {
> +		w = pwrite(rctx->write_fd, unencoded_data + pos,
> +			   unencoded_file_len - pos, offset);
> +		if (w < 0) {
> +			ret = -errno;
> +			error("writing unencoded data failed: %m");
> +			goto out;
> +		}
> +		pos += w;
> +		offset += w;
> +	}
> +out:
> +	free(unencoded_data);
> +	return ret;
> +}
> +
>  static int process_encoded_write(const char *path, const void *data, u64 offset,
> -	u64 len, u64 unencoded_file_len, u64 unencoded_len,
> -	u64 unencoded_offset, u32 compression, u32 encryption, void *user)
> +				 u64 len, u64 unencoded_file_len,
> +				 u64 unencoded_len, u64 unencoded_offset,
> +				 u32 compression, u32 encryption, void *user)

That's irrelevant change for this patch,  it should be squashed in the
previous patch which introduces process_encoded_write.

>  {
>  	int ret;
>  	struct btrfs_receive *rctx = user;
> @@ -1007,6 +1230,7 @@ static int process_encoded_write(const char *path, const void *data, u64 offset,
>  		.compression = compression,
>  		.encryption = encryption,
>  	};
> +	bool encoded_write = !rctx->force_decompress;

No point in the local variable simply use !rctx->force_decompress in the
condition below.

>  
>  	if (encryption) {
>  		error("encoded_write: encryption not supported");
> @@ -1023,13 +1247,21 @@ static int process_encoded_write(const char *path, const void *data, u64 offset,
>  	if (ret < 0)
>  		return ret;
>  
> -	ret = ioctl(rctx->write_fd, BTRFS_IOC_ENCODED_WRITE, &encoded);
> -	if (ret < 0) {
> -		ret = -errno;
> -		error("encoded_write: writing to %s failed: %m", path);
> -		return ret;
> +	if (encoded_write) {
> +		ret = ioctl(rctx->write_fd, BTRFS_IOC_ENCODED_WRITE, &encoded);
> +		if (ret >= 0)
> +			return 0;
> +		/* Fall back for these errors, fail hard for anything else. */
> +		if (errno != ENOSPC && errno != ENOTTY && errno != EINVAL) {
> +			ret = -errno;
> +			error("encoded_write: writing to %s failed: %m", path);
> +			return ret;
> +		}
>  	}
> -	return 0;
> +
> +	return decompress_and_write(rctx, data, offset, len, unencoded_file_len,
> +				    unencoded_len, unencoded_offset,
> +				    compression);
>  }
>  
>  static struct btrfs_send_ops send_ops = {

<snip>


^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands
  2021-09-01 17:01 ` [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands Omar Sandoval
@ 2021-10-21 14:21   ` Nikolay Borisov
  2021-10-21 17:28     ` Omar Sandoval
  0 siblings, 1 reply; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-21 14:21 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <boris@bur.io>
> 
> Send stream v2 can emit fallocate commands, so receive must support them
> as well. The implementation simply passes along the arguments to the
> syscall. Note that mode is encoded as a u32 in send stream but fallocate
> takes an int, so there is a unsigned->signed conversion there.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

However, kernel support for this hasn't landed, the kernel counterpart
patches add definitions but don't actually implement the code. BY the
looks of it it would seem that the proper send stream versioning could
be added first before any of this code lands. In this case we can simply
have the encoded writes stuff as protocol version 2 and leave the rest
of the commands for v3 for example.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 08/10] btrfs-progs: receive: process setflags ioctl commands
  2021-09-01 17:01 ` [PATCH v11 08/10] btrfs-progs: receive: process setflags ioctl commands Omar Sandoval
@ 2021-10-21 14:22   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-21 14:22 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <boris@bur.io>
> 
> In send stream v2, send can emit a command for setting inode flags via
> the setflags ioctl. Pass the flags attribute through to the ioctl call
> in receive.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>


Revewed-by: Nikolay Borisov <nborisov@suse.com>

Same remark about the missing kernel implementation.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands
  2021-10-21 13:33   ` Nikolay Borisov
@ 2021-10-21 16:52     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-21 16:52 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Thu, Oct 21, 2021 at 04:33:00PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Boris Burkov <borisb@fb.com>
> > 
> <snip>
> 
> > +/* Data is not compressed. */
> > +#define BTRFS_ENCODED_IO_COMPRESSION_NONE 0
> > +/* Data is compressed as a single zlib stream. */
> > +#define BTRFS_ENCODED_IO_COMPRESSION_ZLIB 1
> > +/*
> > + * Data is compressed as a single zstd frame with the windowLog compression
> > + * parameter set to no more than 17.
> > + */
> > +#define BTRFS_ENCODED_IO_COMPRESSION_ZSTD 2
> > +/*
> > + * Data is compressed page by page (using the page size indicated by the name of
> > + * the constant) with LZO1X and wrapped in the format documented in
> > + * fs/btrfs/lzo.c. For writes, the compression page size must match the
> > + * filesystem page size.
> > + */
> > +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_4K 3
> > +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_8K 4
> > +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_16K 5
> > +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_32K 6
> > +#define BTRFS_ENCODED_IO_COMPRESSION_LZO_64K 7
> > +#define BTRFS_ENCODED_IO_COMPRESSION_TYPES 8
> 
> nit: Make those an enum ? Same applies for the kernel counterpart patch.

I responded to this before:
https://lore.kernel.org/linux-btrfs/YR%2Fq69Tiz6PFqFJN@relinquished.localdomain/

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent
  2021-10-21 12:44   ` Nikolay Borisov
@ 2021-10-21 16:55     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-21 16:55 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Thu, Oct 21, 2021 at 03:44:52PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:00, Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > Currently, we only create ordered extents when ram_bytes == num_bytes
> > and offset == 0. However, RWF_ENCODED writes may create extents which
> 
> Change RWF_ENCODED to simply encoded as we no longer rely on RWF flags,
> same thing for the changelog in the next patch.

Oops, I checked the diff for stray references to RWF_ENCODED but I
forgot to check the commit messages. Thanks, I'll fix it.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write
  2021-10-21 13:55   ` Nikolay Borisov
@ 2021-10-21 17:22     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-21 17:22 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Thu, Oct 21, 2021 at 04:55:19PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Boris Burkov <boris@bur.io>
> > 
> > +static int decompress_lzo(const char *encoded_data, u64 encoded_len,
> > +			  char *unencoded_data, u64 unencoded_len,
> > +			  unsigned int page_size)
> > +{
> > +	uint32_t total_len;
> > +	size_t in_pos, out_pos;
> > +
> > +	if (encoded_len < 4) {
> > +		error("lzo header is truncated");
> > +		return -EIO;
> > +	}
> > +	memcpy(&total_len, encoded_data, 4);
> > +	total_len = le32toh(total_len);
> > +	if (total_len > encoded_len) {
> > +		error("lzo header is invalid");
> > +		return -EIO;
> > +	}
> > +
> > +	in_pos = 4;
> > +	out_pos = 0;
> > +	while (in_pos < total_len && out_pos < unencoded_len) {
> > +		size_t page_remaining;
> > +		uint32_t src_len;
> > +		lzo_uint dst_len;
> > +		int ret;
> > +
> > +		page_remaining = -in_pos % page_size;
> 
> Why the -in_pos?

in_pos is our position in the encoded data. This calculates how many
bytes are remaining in the page that in_pos current points to.

> > +		if (page_remaining < 4) {
> > +			if (total_len - in_pos <= page_remaining)
> > +				break;
> > +			in_pos += page_remaining;
> > +		}
> > +
> > +		if (total_len - in_pos < 4) {
> > +			error("lzo segment header is truncated");
> > +			return -EIO;
> > +		}
> > +
> > +		memcpy(&src_len, encoded_data + in_pos, 4);
> > +		src_len = le32toh(src_len);
> > +		in_pos += 4;
> > +		if (src_len > total_len - in_pos) {
> > +			error("lzo segment header is invalid");
> > +			return -EIO;
> > +		}
> > +
> > +		dst_len = page_size;
> > +		ret = lzo1x_decompress_safe((void *)(encoded_data + in_pos),
> > +					    src_len,
> > +					    (void *)(unencoded_data + out_pos),
> > +					    &dst_len, NULL);
> > +		if (ret != LZO_E_OK) {
> > +			error("lzo1x_decompress_safe failed: %d", ret);
> > +			return -EIO;
> > +		}
> > +
> > +		in_pos += src_len;
> > +		out_pos += dst_len;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static int decompress_and_write(struct btrfs_receive *rctx,
> > +				const char *encoded_data, u64 offset,
> > +				u64 encoded_len, u64 unencoded_file_len,
> > +				u64 unencoded_len, u64 unencoded_offset,
> > +				u32 compression)
> > +{
> > +	int ret = 0;
> > +	size_t pos;
> > +	ssize_t w;
> > +	char *unencoded_data;
> > +	int page_shift;
> > +
> > +	unencoded_data = calloc(unencoded_len, 1);
> > +	if (!unencoded_data) {
> > +		error("allocating space for unencoded data failed: %m");
> > +		return -errno;
> > +	}
> > +
> > +	switch (compression) {
> > +	case BTRFS_ENCODED_IO_COMPRESSION_ZLIB:
> > +		ret = decompress_zlib(rctx, encoded_data, encoded_len,
> > +				      unencoded_data, unencoded_len);
> > +		if (ret)
> > +			goto out;
> > +		break;
> > +	case BTRFS_ENCODED_IO_COMPRESSION_ZSTD:
> > +		ret = decompress_zstd(rctx, encoded_data, encoded_len,
> > +				      unencoded_data, unencoded_len);
> > +		if (ret)
> > +			goto out;
> > +		break;
> > +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_4K:
> > +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_8K:
> > +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_16K:
> > +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
> > +	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
> > +		page_shift = compression - BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12;
> 
> Doesn't this calculation assume page size is 4k, what about arches with
> larger page size (ppc/aarch64), shouldn't that '12' be adjusted?

This is unrelated to the machine page size. It is translating the
BTRFS_ENCODED_IO_COMPRESSION_LZO_* value to the page size used for
compressing the data:

compression | - LZO_4K | + 12 | 1 <<
=====================================
LZO_4K = 3  | 0        | 12   | 4096
LZO_8K = 4  | 1        | 13   | 8192
LZO_16K = 5 | 2        | 14   | 16384
LZO_32K = 6 | 3        | 15   | 32768
LZO_64K = 7 | 4        | 16   | 65536

I'll fix the other comments, thanks.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands
  2021-10-21 14:21   ` Nikolay Borisov
@ 2021-10-21 17:28     ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-10-21 17:28 UTC (permalink / raw)
  To: Nikolay Borisov; +Cc: linux-btrfs, kernel-team, linux-fsdevel, linux-api

On Thu, Oct 21, 2021 at 05:21:00PM +0300, Nikolay Borisov wrote:
> 
> 
> On 1.09.21 г. 20:01, Omar Sandoval wrote:
> > From: Boris Burkov <boris@bur.io>
> > 
> > Send stream v2 can emit fallocate commands, so receive must support them
> > as well. The implementation simply passes along the arguments to the
> > syscall. Note that mode is encoded as a u32 in send stream but fallocate
> > takes an int, so there is a unsigned->signed conversion there.
> > 
> > Signed-off-by: Boris Burkov <boris@bur.io>
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> 
> However, kernel support for this hasn't landed, the kernel counterpart
> patches add definitions but don't actually implement the code. BY the
> looks of it it would seem that the proper send stream versioning could
> be added first before any of this code lands. In this case we can simply
> have the encoded writes stuff as protocol version 2 and leave the rest
> of the commands for v3 for example.

The original idea for this was to minimize protocol revisions. This way,
when we get around to implementing fallocate on the send side, we
wouldn't need another update on the receive side. I still like that idea
since the receive side is so trivial.

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 09/10] btrfs-progs: send: stream v2 ioctl flags
  2021-09-01 17:01 ` [PATCH v11 09/10] btrfs-progs: send: stream v2 ioctl flags Omar Sandoval
@ 2021-10-22  6:35   ` Nikolay Borisov
  0 siblings, 0 replies; 61+ messages in thread
From: Nikolay Borisov @ 2021-10-22  6:35 UTC (permalink / raw)
  To: Omar Sandoval, linux-btrfs; +Cc: kernel-team, linux-fsdevel, linux-api



On 1.09.21 г. 20:01, Omar Sandoval wrote:
> From: Boris Burkov <boris@bur.io>
> 
> To make the btrfs send ioctl use the stream v2 format requires passing
> BTRFS_SEND_FLAG_STREAM_V2 in flags. Further, to cause the ioctl to emit
> encoded_write commands for encoded extents, we must set that flag as
> well as BTRFS_SEND_FLAG_COMPRESSED. Finally, we bump up the version in
> send.h as well, since we are now fully compatible with v2.
> 
> Add two command line arguments to btrfs send: --stream-version and
> --compressed-data. --stream-version requires an argument which it parses
> as an integer and sets STREAM_V2 if the argument is 2. --compressed-data
> does not require an argument and automatically implies STREAM_V2 as well
> (COMPRESSED alone causes the ioctl to error out).
> 
> Some examples to illustrate edge cases:
> 
> // v1, old format and no encoded_writes
> btrfs send subvol
> btrfs send --stream-version 1 subvol
> 
> // v2 and compressed, we will see encoded_writes
> btrfs send --compressed-data subvol
> btrfs send --compressed-data --stream-version 2 subvol
> 
> // v2 only, new format but no encoded_writes
> btrfs send --stream-version 2 subvol
> 
> // error: compressed needs version >= 2
> btrfs send --compressed-data --stream-version 1 subvol
> 
> // error: invalid version (not 1 or 2)
> btrfs send --stream-version 3 subvol
> btrfs send --compressed-data --stream-version 0 subvol
> btrfs send --compressed-data --stream-version 10 subvol


Why would we want to predicate the compressed writes usage on anything
other than the stream version?

> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> ---
>  Documentation/btrfs-send.asciidoc | 16 ++++++++-
>  cmds/send.c                       | 54 ++++++++++++++++++++++++++++++-
>  ioctl.h                           | 17 +++++++++-
>  libbtrfsutil/btrfs.h              | 17 +++++++++-
>  send.h                            |  2 +-
>  5 files changed, 101 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/btrfs-send.asciidoc b/Documentation/btrfs-send.asciidoc
> index c4a05672..202bcd97 100644
> --- a/Documentation/btrfs-send.asciidoc
> +++ b/Documentation/btrfs-send.asciidoc
> @@ -55,7 +55,21 @@ send in 'NO_FILE_DATA' mode
>  The output stream does not contain any file
>  data and thus cannot be used to transfer changes. This mode is faster and
>  is useful to show the differences in metadata.
> --q|--quiet::::
> +
> +--stream-version <1|2>::
> +Use the given send stream version. The default is 1. Version 2 encodes file
> +data slightly more efficiently; it is also required for sending compressed data
> +directly (see '--compressed-data'). Version 2 requires at least btrfs-progs
> +5.12 on both the sender and receiver and at least Linux 5.12 on the sender.
> +

The version of progs needs to be adjusted but I assume this will be done
by David when this patchset is merged as we don't have a target ATM.

> +--compressed-data::
> +Send data that is compressed on the filesystem directly without decompressing
> +it. If the receiver supports encoded I/O (see `encoded_io`(7)), it can also
> +write it directly without decompressing it. Otherwise, the receiver will fall
> +back to decompressing it and writing it normally. This implies
> +'--stream-version 2'.
> +
> +-q|--quiet::
>  (deprecated) alias for global '-q' option
>  -v|--verbose::
>  (deprecated) alias for global '-v' option
> diff --git a/cmds/send.c b/cmds/send.c
> index 3bfc69f5..80eb2510 100644
> --- a/cmds/send.c
> +++ b/cmds/send.c
> @@ -452,6 +452,21 @@ static const char * const cmd_send_usage[] = {
>  	"                 does not contain any file data and thus cannot be used",
>  	"                 to transfer changes. This mode is faster and useful to",
>  	"                 show the differences in metadata.",
> +	"--stream-version <1|2>",
> +	"                 Use the given send stream version. The default is",
> +	"                 1. Version 2 encodes file data slightly more",
> +	"                 efficiently; it is also required for sending",
> +	"                 compressed data directly (see --compressed-data).",
> +	"                 Version 2 requires at least btrfs-progs 5.12 on both",
> +	"                 the sender and receiver and at least Linux 5.12 on the",
> +	"                 sender.",

Ditto

<snip>

^ permalink raw reply	[flat|nested] 61+ messages in thread

* Re: [PATCH v11 01/14] fs: export rw_verify_area()
  2021-09-01 17:00 ` [PATCH v11 01/14] fs: export rw_verify_area() Omar Sandoval
@ 2021-11-18 19:19   ` Omar Sandoval
  0 siblings, 0 replies; 61+ messages in thread
From: Omar Sandoval @ 2021-11-18 19:19 UTC (permalink / raw)
  To: linux-btrfs, Alexander Viro, Christoph Hellwig, Linus Torvalds
  Cc: kernel-team, linux-fsdevel, linux-api

On Wed, Sep 01, 2021 at 10:00:56AM -0700, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> I'm adding Btrfs ioctls to read and write compressed data, and rather
> than duplicating the checks in rw_verify_area(), let's just export it.
> 
> Reviewed-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
>  fs/internal.h      | 5 -----
>  fs/read_write.c    | 1 +
>  include/linux/fs.h | 1 +
>  3 files changed, 2 insertions(+), 5 deletions(-)

Could I please get an ack from the VFS side on this patch and "fs:
export variant of generic_write_checks without iov_iter"? We're going
the route of doing this as a Btrfs ioctl since we couldn't agree on a
generic interface, so this is all I need from the VFS.

^ permalink raw reply	[flat|nested] 61+ messages in thread

end of thread, other threads:[~2021-11-18 19:19 UTC | newest]

Thread overview: 61+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-01 17:00 [PATCH v11 00/14] btrfs: add ioctls and send/receive support for reading/writing compressed data Omar Sandoval
2021-09-01 17:00 ` [PATCH v11 01/14] fs: export rw_verify_area() Omar Sandoval
2021-11-18 19:19   ` Omar Sandoval
2021-09-01 17:00 ` [PATCH v11 02/14] fs: export variant of generic_write_checks without iov_iter Omar Sandoval
2021-10-14 12:03   ` Nikolay Borisov
2021-09-01 17:00 ` [PATCH v11 03/14] btrfs: don't advance offset for compressed bios in btrfs_csum_one_bio() Omar Sandoval
2021-10-14 12:05   ` Nikolay Borisov
2021-10-18 18:09     ` Omar Sandoval
2021-09-01 17:00 ` [PATCH v11 04/14] btrfs: add ram_bytes and offset to btrfs_ordered_extent Omar Sandoval
2021-10-21 12:44   ` Nikolay Borisov
2021-10-21 16:55     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 05/14] btrfs: support different disk extent size for delalloc Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 06/14] btrfs: optionally extend i_size in cow_file_range_inline() Omar Sandoval
2021-10-14 12:54   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 07/14] btrfs: add definitions + documentation for encoded I/O ioctls Omar Sandoval
2021-10-15  9:42   ` Nikolay Borisov
2021-10-18 18:16     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 08/14] btrfs: add BTRFS_IOC_ENCODED_READ Omar Sandoval
2021-10-15 11:45   ` Nikolay Borisov
2021-10-18 23:59     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 09/14] btrfs: add BTRFS_IOC_ENCODED_WRITE Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 10/14] btrfs: add send stream v2 definitions Omar Sandoval
2021-10-18 12:46   ` Nikolay Borisov
2021-10-18 15:11   ` Nikolay Borisov
2021-10-18 18:58     ` Omar Sandoval
2021-10-19  7:01       ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 11/14] btrfs: send: write larger chunks when using stream v2 Omar Sandoval
2021-10-18 12:57   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 12/14] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2 Omar Sandoval
2021-10-18 11:10   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 13/14] btrfs: send: send compressed extents with encoded writes Omar Sandoval
2021-10-18 11:59   ` Nikolay Borisov
2021-10-19  0:11     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 14/14] btrfs: send: enable support for stream v2 and compressed writes Omar Sandoval
2021-10-18 12:44   ` Nikolay Borisov
2021-10-18 18:34     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 01/10] btrfs-progs: receive: support v2 send stream larger tlv_len Omar Sandoval
2021-10-20 13:49   ` Nikolay Borisov
2021-10-20 18:48     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 02/10] btrfs-progs: receive: dynamically allocate sctx->read_buf Omar Sandoval
2021-10-20 14:09   ` Nikolay Borisov
2021-10-20 14:35     ` Nikolay Borisov
2021-10-20 17:44       ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 03/10] btrfs-progs: receive: support v2 send stream DATA tlv format Omar Sandoval
2021-10-20 14:36   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 04/10] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h Omar Sandoval
2021-10-20 14:38   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 05/10] btrfs-progs: receive: process encoded_write commands Omar Sandoval
2021-10-21 13:33   ` Nikolay Borisov
2021-10-21 16:52     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 06/10] btrfs-progs: receive: encoded_write fallback to explicit decode and write Omar Sandoval
2021-10-21 13:55   ` Nikolay Borisov
2021-10-21 17:22     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 07/10] btrfs-progs: receive: process fallocate commands Omar Sandoval
2021-10-21 14:21   ` Nikolay Borisov
2021-10-21 17:28     ` Omar Sandoval
2021-09-01 17:01 ` [PATCH v11 08/10] btrfs-progs: receive: process setflags ioctl commands Omar Sandoval
2021-10-21 14:22   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 09/10] btrfs-progs: send: stream v2 ioctl flags Omar Sandoval
2021-10-22  6:35   ` Nikolay Borisov
2021-09-01 17:01 ` [PATCH v11 10/10] btrfs-progs: receive: add tests for basic encoded_write send/receive Omar Sandoval

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