Commit deccae40 authored Jun 09, 2023 by Chris Mason Committed by David Sterba Jun 13, 2023

btrfs: can_nocow_file_extent should pass down args->strict from callers



Commit 619104ba ("btrfs: move common NOCOW checks against a file
extent into a helper") changed our call to btrfs_cross_ref_exist() to
always pass false for the 'strict' parameter.  We're passing this down
through the stack so that we can do a full check for cross references
during swapfile activation.

With strict always false, this test fails:

  btrfs subvol create swappy
  chattr +C swappy
  fallocate -l1G swappy/swapfile
  chmod 600 swappy/swapfile
  mkswap swappy/swapfile

  btrfs subvol snap swappy swapsnap
  btrfs subvol del -C swapsnap

  btrfs fi sync /
  sync;sync;sync

  swapon swappy/swapfile

The fix is to just use args->strict, and everyone except swapfile
activation is passing false.

Fixes: 619104ba ("btrfs: move common NOCOW checks against a file extent into a helper")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 7833b865

fs/btrfs/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1864,7 +1864,7 @@ static int can_nocow_file_extent(struct btrfs_path *path,

		ret = btrfs_cross_ref_exist(root, btrfs_ino(inode),
		key->offset - args->extent_offset,
		args->disk_bytenr, false, path);
		args->disk_bytenr, args->strict, path);
		WARN_ON_ONCE(ret > 0 && is_freespace_inode);
		if (ret != 0)
		goto out;