From: Keith Busch <kbusch@kernel.org>
To: Daniel Wagner <dwagner@suse.de>
Cc: Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
Chris Leech <cleech@redhat.com>,
linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
Dmitry Bogdanov <d.bogdanov@yadro.com>,
Daniel Wagner <wagi@kernel.org>
Subject: Re: [PATCH] nvme-tcp: fix usage of page_frag_cache
Date: Mon, 10 Aug 2026 17:40:21 -0600 [thread overview]
Message-ID: <anphZRzJvg0zSE6g@kbusch-mbp> (raw)
In-Reply-To: <20260716-nvme-tcp-page_fraq_cache-v1-1-ea660828cf93@kernel.org>
On Thu, Jul 16, 2026 at 04:42:19PM +0200, Daniel Wagner wrote:
> From: Dmitry Bogdanov <d.bogdanov@yadro.com>
>
> nvme uses page_frag_cache to preallocate PDU for each preallocated request
> of block device. Block devices are created in parallel threads,
> consequently page_frag_cache is used in not thread-safe manner.
> That leads to incorrect refcounting of backstore pages and premature free.
I was struggling to see how the nvme_tcp callback was happening
concurrently for the same queue. It's because you're using an io
scheduler, right? I don't think this applies if you don't have one
enabled.
Anyway, with that understanding, looks like a safe patch. Applied to
nvme-7.3.
next prev parent reply other threads:[~2026-08-10 23:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-16 14:42 [PATCH] nvme-tcp: fix usage of page_frag_cache Daniel Wagner
2026-08-06 12:46 ` Daniel Wagner
2026-08-10 23:40 ` Keith Busch [this message]
-- strict thread matches above, loose matches on Subject: below --
2025-09-29 11:19 Dmitry Bogdanov
2025-10-01 6:31 ` Chris Leech
2025-10-01 16:41 ` Dmitry Bogdanov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=anphZRzJvg0zSE6g@kbusch-mbp \
--to=kbusch@kernel.org \
--cc=cleech@redhat.com \
--cc=d.bogdanov@yadro.com \
--cc=dwagner@suse.de \
--cc=hch@lst.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=sagi@grimberg.me \
--cc=wagi@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).