btrfs: zoned: fix comparison of alloc_offset vs meta_write_pointer

commit aa9ffad upstream.

The block_group->alloc_offset is an offset from the start of the block
group. OTOH, the ->meta_write_pointer is an address in the logical
space. So, we should compare the alloc_offset shifted with the
block_group->start.

Fixes: afba2bc ("btrfs: zoned: implement active zone tracking")
CC: stable@vger.kernel.org # 5.16+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/btrfs/zoned.c

@@ -1863,7 +1863,7 @@ int btrfs_zone_finish(struct btrfs_block_group *block_group)
 	/* Check if we have unwritten allocated space */
 	if ((block_group->flags &
 	     (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM)) &&
-	    block_group->alloc_offset > block_group->meta_write_pointer) {
+	    block_group->start + block_group->alloc_offset > block_group->meta_write_pointer) {
 		spin_unlock(&block_group->lock);
 		return -EAGAIN;
 	}