From: Christoph Hellwig <hch@lst.de>
To: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: linux-btrfs@vger.kernel.org, Filipe Manana <fdmanana@suse.com>,
David Sterba <dsterba@suse.com>,
Hans Holmberg <Hans.Holmberg@wdc.com>,
Boris Burkov <boris@bur.io>, Damien Le Moal <dlemoal@kernel.org>,
Naohiro Aota <naohiro.aota@wdc.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 5/7] btrfs: zoned: subtract zone_unusable space in statfs
Date: Fri, 15 May 2026 06:39:21 +0200 [thread overview]
Message-ID: <20260515043921.GB3936@lst.de> (raw)
In-Reply-To: <20260513123445.43197-6-johannes.thumshirn@wdc.com>
On Wed, May 13, 2026 at 02:34:43PM +0200, Johannes Thumshirn wrote:
> On zoned filesystems, space in block groups that has been freed but not
> yet reset is tracked in bytes_zone_unusable. This space cannot be used for
> new allocations until zone reclaim resets the zones, but it was being
> reported as available space in statfs.
>
> This caused statfs to over-report free space, leading to ENOSPC errors
> when applications tried to allocate based on the reported free space.
>
> Fix this by subtracting bytes_zone_unusable from total_free_data in the
> statfs calculation for zoned filesystems.
This OTOH sounds very wrong. Freed but not reclaimed space is usable,
it just needs work.
next prev parent reply other threads:[~2026-05-15 4:39 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-13 12:34 [PATCH 0/7] btrfs: fixes around generic/747 on zoned filesystems Johannes Thumshirn
2026-05-13 12:34 ` [PATCH 1/7] btrfs: zoned: document RECLAIM_ZONES flush state Johannes Thumshirn
2026-05-14 14:44 ` Boris Burkov
2026-05-13 12:34 ` [PATCH 2/7] btrfs: zoned: decode 'RECLAIM_ZONES' state in tracepoints Johannes Thumshirn
2026-05-13 12:34 ` [PATCH 3/7] btrfs: zoned: always set data_relocation_bg Johannes Thumshirn
2026-05-14 5:42 ` Damien Le Moal
2026-05-14 14:54 ` Boris Burkov
2026-05-13 12:34 ` [PATCH 4/7] btrfs: zoned: don't account data relocation space-info in statfs free space Johannes Thumshirn
2026-05-14 5:42 ` Damien Le Moal
2026-05-15 4:38 ` Christoph Hellwig
2026-05-13 12:34 ` [PATCH 5/7] btrfs: zoned: subtract zone_unusable space in statfs Johannes Thumshirn
2026-05-14 5:43 ` Damien Le Moal
2026-05-15 4:39 ` Christoph Hellwig [this message]
2026-05-13 12:34 ` [PATCH 6/7] btrfs: zoned: fix deadlock waiting for ticket during data relocation Johannes Thumshirn
2026-05-13 12:34 ` [RFC PATCH 7/7] btrfs: zoned: add RECLAIM_ZONES and RESET_ZONES to first async reclaim loop Johannes Thumshirn
2026-05-14 14:43 ` [PATCH 0/7] btrfs: fixes around generic/747 on zoned filesystems Boris Burkov
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