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-rw-r--r--0004-btrfs-send-fix-emission-of-invalid-clone-operations-within-the-same.patch114
1 files changed, 0 insertions, 114 deletions
diff --git a/0004-btrfs-send-fix-emission-of-invalid-clone-operations-within-the-same.patch b/0004-btrfs-send-fix-emission-of-invalid-clone-operations-within-the-same.patch
deleted file mode 100644
index 496cc6f..0000000
--- a/0004-btrfs-send-fix-emission-of-invalid-clone-operations-within-the-same.patch
+++ /dev/null
@@ -1,114 +0,0 @@
-From 693469a2b9d6d27282c06ed55cb70ff648740efd Mon Sep 17 00:00:00 2001
-From: Filipe Manana <fdmanana@suse.com>
-Date: Fri, 24 Jan 2020 11:52:04 +0000
-Subject: Btrfs: send, fix emission of invalid clone operations within the same
- file
-
-When doing an incremental send and a file has extents shared with itself
-at different file offsets, it's possible for send to emit clone operations
-that will fail at the destination because the source range goes beyond the
-file's current size. This happens when the file size has increased in the
-send snapshot, there is a hole between the shared extents and both shared
-extents are at file offsets which are greater the file's size in the
-parent snapshot.
-
-Example:
-
- $ mkfs.btrfs -f /dev/sdb
- $ mount /dev/sdb /mnt/sdb
-
- $ xfs_io -f -c "pwrite -S 0xf1 0 64K" /mnt/sdb/foobar
- $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/base
- $ btrfs send -f /tmp/1.snap /mnt/sdb/base
-
- # Create a 320K extent at file offset 512K.
- $ xfs_io -c "pwrite -S 0xab 512K 64K" /mnt/sdb/foobar
- $ xfs_io -c "pwrite -S 0xcd 576K 64K" /mnt/sdb/foobar
- $ xfs_io -c "pwrite -S 0xef 640K 64K" /mnt/sdb/foobar
- $ xfs_io -c "pwrite -S 0x64 704K 64K" /mnt/sdb/foobar
- $ xfs_io -c "pwrite -S 0x73 768K 64K" /mnt/sdb/foobar
-
- # Clone part of that 320K extent into a lower file offset (192K).
- # This file offset is greater than the file's size in the parent
- # snapshot (64K). Also the clone range is a bit behind the offset of
- # the 320K extent so that we leave a hole between the shared extents.
- $ xfs_io -c "reflink /mnt/sdb/foobar 448K 192K 192K" /mnt/sdb/foobar
-
- $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/incr
- $ btrfs send -p /mnt/sdb/base -f /tmp/2.snap /mnt/sdb/incr
-
- $ mkfs.btrfs -f /dev/sdc
- $ mount /dev/sdc /mnt/sdc
-
- $ btrfs receive -f /tmp/1.snap /mnt/sdc
- $ btrfs receive -f /tmp/2.snap /mnt/sdc
- ERROR: failed to clone extents to foobar: Invalid argument
-
-The problem is that after processing the extent at file offset 192K, send
-does not issue a write operation full of zeroes for the hole between that
-extent and the extent starting at file offset 520K (hole range from 384K
-to 512K), this is because the hole is at an offset larger the size of the
-file in the parent snapshot (384K > 64K). As a consequence the field
-'cur_inode_next_write_offset' of the send context remains with a value of
-384K when we start to process the extent at file offset 512K, which is the
-value set after processing the extent at offset 192K.
-
-This screws up the lookup of possible extents to clone because due to an
-incorrect value of 'cur_inode_next_write_offset' we can now consider
-extents for cloning, in the same inode, that lie beyond the current size
-of the file in the receiver of the send stream. Also, when checking if
-an extent in the same file can be used for cloning, we must also check
-that not only its start offset doesn't start at or beyond the current eof
-of the file in the receiver but that the source range doesn't go beyond
-current eof, that is we must check offset + length does not cross the
-current eof, as that makes clone operations fail with -EINVAL.
-
-So fix this by updating 'cur_inode_next_write_offset' whenever we start
-processing an extent and checking an extent's offset and length when
-considering it for cloning operations.
-
-A test case for fstests follows soon.
-
-Fixes: 11f2069c113e02 ("Btrfs: send, allow clone operations within the same file")
-Signed-off-by: Filipe Manana <fdmanana@suse.com>
-Reviewed-by: Josef Bacik <josef@toxicpanda.com>
----
- fs/btrfs/send.c | 15 ++++++++++++++-
- 1 file changed, 14 insertions(+), 1 deletion(-)
-
-diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
-index 091e5bc8c7ea..0b42dac8a35f 100644
---- a/fs/btrfs/send.c
-+++ b/fs/btrfs/send.c
-@@ -1269,7 +1269,8 @@ static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
- * destination of the stream.
- */
- if (ino == bctx->cur_objectid &&
-- offset >= bctx->sctx->cur_inode_next_write_offset)
-+ offset + bctx->extent_len >
-+ bctx->sctx->cur_inode_next_write_offset)
- return 0;
- }
-
-@@ -5804,6 +5805,18 @@ static int process_extent(struct send_ctx *sctx,
- }
- }
-
-+ /*
-+ * There might be a hole between the end of the last processed extent
-+ * and this extent, and we may have not sent a write operation for that
-+ * hole because it was not needed (range is beyond eof in the parent
-+ * snapshot). So adjust the next write offset to the offset of this
-+ * extent, as we want to make sure we don't do mistakes when checking if
-+ * we can clone this extent from some other offset in this inode or when
-+ * detecting if we need to issue a truncate operation when finishing the
-+ * processing this inode.
-+ */
-+ sctx->cur_inode_next_write_offset = key->offset;
-+
- ret = find_extent_clone(sctx, path, key->objectid, key->offset,
- sctx->cur_inode_size, &found_clone);
- if (ret != -ENOENT && ret < 0)
---
-cgit v1.2.1-1-g437b
-