Re: [PATCH v2 0/2] btrfs-progs: fix stale active zone after mkfs

[David Sterba <dsterba@suse.cz>]

On Fri, Sep 04, 2026 at 08:24:42AM +0200, Johannes Thumshirn wrote:
> On zoned devices, mkfs can leave a stale zone behind that is used as a
> staging area but never reset. This zone is not backed by a chunk or
> device extent, so the FS itself does not account it as used. On devices
> that have a limitied active zone budget this can lead to premature
> ENOSPC and/or an exhaustion of active zones.
> 
> Fix it in mkfs for new file-systems and also add a check to fsck to find
> such zones and repair them with '--repair'.
> 
> Changes to v1:
> - fix a bug in fsck where it had a stale return value propagated.
> 
> Johannes Thumshirn (2):
>   btrfs-progs: zoned: refresh stale cached zone state in
>     btrfs_reset_dev_zone()
>   btrfs-progs: check: detect leaked active zones on zoned devices

The build fails on older distros (Centos 8, Leap 15.3/16.0):

  CC       check/main.o
check/main.c: In function 'check_zoned_active_zones':
check/main.c:9220:12: error: 'struct blk_zone' has no member named 'type'
    if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
            ^~
check/main.c:9220:22: error: 'BLK_ZONE_TYPE_CONVENTIONAL' undeclared (first use in this function)
    if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
check/main.c:9220:22: note: each undeclared identifier is reported only once for each function it appears in
check/main.c:9222:12: error: 'struct blk_zone' has no member named 'cond'
    if (zone->cond == BLK_ZONE_COND_EMPTY)
            ^~
check/main.c:9222:22: error: 'BLK_ZONE_COND_EMPTY' undeclared (first use in this function)
    if (zone->cond == BLK_ZONE_COND_EMPTY)
                      ^~~~~~~~~~~~~~~~~~~

The types were added in f5f2bad67a45 ("block: make the new blkzoned UAPI
constants discoverable") in 2016 and with the rest of the zoned userspace code
so it's not something recent.

I haven't looked what's the problem, this should be reproducible locally using
the "ci/ci-centos8" scripts (needs docker).