Commit 4fdb688c authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba

btrfs: fix lost i_size update after cloning inline extent

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.

Link: https://lore.kernel.org/linux-btrfs/20200404193846.GA432065@latitude/Reported-by: default avatarJohannes Hirte <johannes.hirte@datenkhaos.de>
Fixes: 9ddc959e ("btrfs: use the file extent tree infrastructure")
Tested-by: default avatarJohannes Hirte <johannes.hirte@datenkhaos.de>
Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 4d4225fc
...@@ -264,6 +264,7 @@ static int clone_copy_inline_extent(struct inode *dst, ...@@ -264,6 +264,7 @@ static int clone_copy_inline_extent(struct inode *dst,
size); size);
inode_add_bytes(dst, datal); inode_add_bytes(dst, datal);
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(dst)->runtime_flags); 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: out:
if (!ret && !trans) { if (!ret && !trans) {
/* /*
......
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