btrfs: don't clear qgroup reserved bit in release_folio
authorBoris Burkov <boris@bur.io>
Fri, 1 Dec 2023 21:00:12 +0000 (13:00 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 20 Dec 2023 16:02:03 +0000 (17:02 +0100)
commitd3cf024353e213989a48399ed9ed24775e6472f0
tree34b1e3ae2352d20d3de868c5382a559657b12767
parent1823491513e3f72beb85f7fba2478ef3562615d8
btrfs: don't clear qgroup reserved bit in release_folio

commit a86805504b88f636a6458520d85afdf0634e3c6b upstream.

The EXTENT_QGROUP_RESERVED bit is used to "lock" regions of the file for
duplicate reservations. That is two writes to that range in one
transaction shouldn't create two reservations, as the reservation will
only be freed once when the write finally goes down. Therefore, it is
never OK to clear that bit without freeing the associated qgroup
reserve. At this point, we don't want to be freeing the reserve, so mask
off the bit.

CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/btrfs/extent_io.c