btrfs: zoned: clear data relocation bg on zone finish

When finishing a zone that is used by a dedicated data relocation
block group, also remove its reference from fs_info, so we're not trying
to use a full block group for allocations during data relocation, which
will always fail.

The result is we're not making any forward progress and end up in a
deadlock situation.

Fixes: c2707a2 ("btrfs: zoned: add a dedicated data relocation block group")
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: morbidrsa

fs/btrfs/zoned.c

@@ -1860,6 +1860,7 @@ int btrfs_zone_finish(struct btrfs_block_group *block_group)
 	block_group->alloc_offset = block_group->zone_capacity;
 	block_group->free_space_ctl->free_space = 0;
 	btrfs_clear_treelog_bg(block_group);
+	btrfs_clear_data_reloc_bg(block_group);
 	spin_unlock(&block_group->lock);
 
 	ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
@@ -1942,6 +1943,7 @@ void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical, u64 len
 	ASSERT(block_group->alloc_offset == block_group->zone_capacity);
 	ASSERT(block_group->free_space_ctl->free_space == 0);
 	btrfs_clear_treelog_bg(block_group);
+	btrfs_clear_data_reloc_bg(block_group);
 	spin_unlock(&block_group->lock);
 
 	map = block_group->physical_map;