From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <kbusch@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
axboe@kernel.dk, z1281552865@gmail.com,
linux-block@vger.kernel.org
Subject: Re: [PATCH] block: fix aligning of bounced dio read bios
Date: Mon, 13 Jul 2026 17:54:52 +0200 [thread overview]
Message-ID: <20260713155452.GA4005@lst.de> (raw)
In-Reply-To: <alUH3a7hP1tytq4a@kbusch-mbp>
On Mon, Jul 13, 2026 at 09:44:29AM -0600, Keith Busch wrote:
> On Mon, Jul 13, 2026 at 09:39:01AM -0600, Keith Busch wrote:
> > On Mon, Jul 13, 2026 at 05:29:11PM +0200, Christoph Hellwig wrote:
> > > bio_iov_iter_align_down expects the "normal" biovec layout from vector 0,
> > > while bio_iov_iter_bounce_read abuses vector 0 for a bounce buffer
> > > allocation. Pass an explicit bvec to bio_iov_iter_align_down to deal
> > > with this case to avoid a double unpin.
> >
> > Can you instead just have bio_iov_iter_bounce_read() align down the size
> > it extracts rather than letting it over-extract and reverting the excess?
>
> Oh sorry, nevermind. We can do partial extractions, so we don't
> necessarily know where we're going to end, so have to align after
> constructing the bio vec.
Yeah. Although we could try to do this in the iov_iter_extract_bvecs
similar to your recent fix. Which is proobably the better idea
here. Let me give that version a spin.
next prev parent reply other threads:[~2026-07-13 15:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-13 15:29 [PATCH] block: fix aligning of bounced dio read bios Christoph Hellwig
2026-07-13 15:39 ` Keith Busch
2026-07-13 15:44 ` Keith Busch
2026-07-13 15:54 ` Christoph Hellwig [this message]
2026-07-14 6:10 ` [syzbot ci] " syzbot ci
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