Re: [PATCH] btrfs: zoned: finish active block group cleanup if call_zone_finish() fails

在 2026/8/19 19:56, Johannes Thumshirn 写道:
> do_zone_finish() clears BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE before finishing
> the zones. If call_zone_finish() then fails it returned early, leaving the
> now inactive block group on fs_info->zone_active_bgs, leaking its
> reference, the BTRFS_FS_NEED_ZONE_FINISH waiters are never woken, and as
> its alloc_offset equals the zone capacity btrfs_zone_finish_one_bg() keeps
> selecting it, spinning btrfs_zoned_activate_one_bg().
> 
> Fall through to the cleanup on failure too and return the error, but keep
> the block group read-only as its zones are left inconsistent.
> 
> Fixes: d70cbdda75da ("btrfs: zoned: consolidate zone finish functions")
> Link: https://sashiko.dev/#/patchset/20260818100037.1366563-1-johannes.thumshirn%40wdc.com
> Signed-off-by: Johannes Thumshirn <[email protected]>
> ---
>   fs/btrfs/zoned.c | 10 ++++------
>   1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
> index 82c2394dd43c..9d448cdd60c4 100644
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -2628,14 +2628,12 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
>   	for (i = 0; i < map->num_stripes; i++) {
>   
>   		ret = call_zone_finish(block_group, &map->stripes[i]);
> -		if (ret) {
> -			up_read(&dev_replace->rwsem);
> -			return ret;
> -		}
> +		if (ret)
> +			break;

I'm wondering should we continue to finish the other stripes instead?

>   	}
>   	up_read(&dev_replace->rwsem);
>   
> -	if (!fully_written)
> +	if (!ret && !fully_written)

Not familiar with zoned code, but if we hit an error, the block group 
will stay RO.

Is that the expected behavior?

The branch for bg with FLAG_ZONED_DATA_RELOC case, we return -EAGAIN but 
decrease the bg RO before returning.

So it looks like we should always decrease the bg RO even for error case?

Thanks,
Qu

>   		btrfs_dec_block_group_ro(block_group);
>   
>   	spin_lock(&fs_info->zone_active_bgs_lock);
> @@ -2648,7 +2646,7 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
>   
>   	clear_and_wake_up_bit(BTRFS_FS_NEED_ZONE_FINISH, &fs_info->flags);
>   
> -	return 0;
> +	return ret;
>   }
>   
>   int btrfs_zone_finish(struct btrfs_block_group *block_group)