[PATCH 6.6 318/396] btrfs: zoned: dont skip block groups with 100% zone unusable

Greg Kroah-Hartman
2024-04-01T16:52:08Z

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

commit a8b70c7f8600bc77d03c0b032c0662259b9e615e upstream.

Commit f4a9f219411f ("btrfs: do not delete unused block group if it may be
used soon") changed the behaviour of deleting unused block-groups on zoned
filesystems. Starting with this commit, we're using
btrfs_space_info_used() to calculate the number of used bytes in a
space_info. But btrfs_space_info_used() also accounts
btrfs_space_info::bytes_zone_unusable as used bytes.

So if a block group is 100% zone_unusable it is skipped from the deletion
step.

In order not to skip fully zone_unusable block-groups, also check if the
block-group has bytes left that can be used on a zoned filesystem.

Fixes: f4a9f219411f ("btrfs: do not delete unused block group if it may be used soon")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.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>
---
fs/btrfs/block-group.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1562,7 +1562,8 @@ void btrfs_delete_unused_bgs(struct btrf
* needing to allocate extents from the block group.
*/
used = btrfs_space_info_used(space_info, true);
- if (space_info->total_bytes - block_group->length < used) {
+ if (space_info->total_bytes - block_group->length < used &&
+ block_group->zone_unusable < block_group->length) {
/*
* Add a reference for the list, compensate for the ref
* drop under the "next" label for the