From: Christoph Hellwig <hch@infradead.org>
To: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Jens Axboe <axboe@kernel.dk>,
drbd-dev@lists.linbit.com, linux-kernel@vger.kernel.org,
Lars Ellenberg <lars.ellenberg@linbit.com>,
Philipp Reisner <philipp.reisner@linbit.com>,
linux-block@vger.kernel.org
Subject: Re: [PATCH] drbd: always set BLK_FEAT_STABLE_WRITES
Date: Thu, 12 Feb 2026 22:05:54 -0800 [thread overview]
Message-ID: <aY6_Qg3gPKBPdttw@infradead.org> (raw)
In-Reply-To: <eaa83421-a07a-4ee7-81ad-f32d4a237ff8@linbit.com>
On Thu, Feb 12, 2026 at 04:01:43PM +0100, Christoph Böhmwalder wrote:
> The current block layer logic actually seems correct to me. The
> underlying device may or may not require stable writes, but regardless
> of that, DRBD itself definitely does need it. In blk_stack_limits, DRBD
> is the top device, and DRBD's backing disk is the bottom device. If the
> backing disk happens to require stable writes, this would indeed be
> correctly inherited.
>
> So the only missing logic is that DRBD still wants to enable stable
> writes for itself even if the backing disk does *not* request it.
> So it seems to me that this patch is the correct fix for DRBD's special
> case.
>
> Is it not supposed to work like that?
No, I guess I just misunderstood your report.
next prev parent reply other threads:[~2026-02-13 6:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-05 17:39 [PATCH] drbd: always set BLK_FEAT_STABLE_WRITES Christoph Böhmwalder
2026-02-06 6:43 ` Christoph Hellwig
2026-02-12 15:01 ` Christoph Böhmwalder
2026-02-13 6:05 ` Christoph Hellwig [this message]
2026-02-11 17:36 ` Jens Axboe
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