btrfs: zoned: do not select metadata BG as finish target

We call btrfs_zone_finish_one_bg() to zone finish one block group and make
room to activate another block group. Currently, we can choose a metadata
block group as a target. But, as we reserve an active metadata block group,
we no longer want to select a metadata block group. So, skip it in the
loop.

Signed-off-by: Naohiro Aota <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>

Author: naota

fs/btrfs/zoned.c

@@ -2671,7 +2671,7 @@ int btrfs_zone_finish_one_bg(struct btrfs_fs_info *fs_info)
 
 		spin_lock(&block_group->lock);
 		if (block_group->reserved || block_group->alloc_offset == 0 ||
-		    (block_group->flags & BTRFS_BLOCK_GROUP_SYSTEM) ||
+		    !(block_group->flags & BTRFS_BLOCK_GROUP_DATA) ||
 		    test_bit(BLOCK_GROUP_FLAG_ZONED_DATA_RELOC, &block_group->runtime_flags)) {
 			spin_unlock(&block_group->lock);
 			continue;