btrfs: unlock extents in btrfs_zero_range in case of quota reservation errors

commit 4f6a49d upstream.

If btrfs_qgroup_reserve_data returns an error (i.e quota limit reached)
the handling logic directly goes to the 'out' label without first
unlocking the extent range between lockstart, lockend. This results in
deadlocks as other processes try to lock the same extent.

Fixes: a7f8b1c ("btrfs: file: reserve qgroup space after the hole punch range is locked")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: lorddoskias

fs/btrfs/file.c

@@ -3236,8 +3236,11 @@ static int btrfs_zero_range(struct inode *inode,
 			goto out;
 		ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
 						alloc_start, bytes_to_reserve);
-		if (ret)
+		if (ret) {
+			unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
+					     lockend, &cached_state);
 			goto out;
+		}
 		ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
 						alloc_end - alloc_start,
 						i_blocksize(inode),