From: Filipe Manana <fdmanana@xxxxxxxx>
When not using the NO_HOLES feature we were not marking the destination's
file range as written after cloning an inline extent into it. This can
lead to a data loss if the current destination file size is smaller than
the source file's size.
Example:
$ mkfs.btrfs -f -O ^no-holes /dev/sdc
$ mount /mnt/sdc /mnt
$ echo "hello world" > /mnt/foo
$ cp --reflink=always /mnt/foo /mnt/bar
$ rm -f /mnt/foo
$ umount /mnt
$ mount /mnt/sdc /mnt
$ cat /mnt/bar
$
$ stat -c %s /mnt/bar
0
# -> the file is empty, since we deleted foo, the data lost is forever
Fix that by calling btrfs_inode_set_file_extent_range() after cloning an
inline extent.
A test case for fstests will follow soon.
Fixes: 9ddc959e802bf ("btrfs: use the file extent tree infrastructure")
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
---
fs/btrfs/reflink.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index d1973141d3bb..040009d1cc31 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -264,6 +264,7 @@ static int clone_copy_inline_extent(struct inode *dst,
size);
inode_add_bytes(dst, datal);
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(dst)->runtime_flags);
+ ret = btrfs_inode_set_file_extent_range(BTRFS_I(dst), 0, aligned_end);
out:
if (!ret && !trans) {
/*
--
2.11.0
