linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Minchan Kim <minchan@kernel.org>
Cc: linux-mm <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Chris Goldsworthy <cgoldswo@codeaurora.org>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	John Dias <joaodias@google.com>
Subject: Re: [PATCH] mm: fs: fix lru_cache_disabled race in bh_lru
Date: Wed, 9 Mar 2022 14:06:27 -0800	[thread overview]
Message-ID: <20220309140627.eeaa069daa921dbef64f8970@linux-foundation.org> (raw)
In-Reply-To: <20220308180709.2017638-1-minchan@kernel.org>

On Tue,  8 Mar 2022 10:07:09 -0800 Minchan Kim <minchan@kernel.org> wrote:

> Check lru_cache_disabled under bh_lru_lock. Otherwise, it could
> introduce race below and it fails to migrate pages containing
> buffer_head.
> 
>    CPU 0					CPU 1
> 
> bh_lru_install
>                                        lru_cache_disable
>   lru_cache_disabled = false
>                                        atomic_inc(&lru_disable_count);
> 				       invalidate_bh_lrus_cpu of CPU 0
> 				       bh_lru_lock
> 				       __invalidate_bh_lrus
> 				       bh_lru_unlock
>   bh_lru_lock
>   install the bh
>   bh_lru_unlock

What are the user-visible runtime effects of this bug?

Is a cc:stable needed?

Should there be a reported-by?

Thanks.



  reply	other threads:[~2022-03-09 22:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-08 18:07 Minchan Kim
2022-03-09 22:06 ` Andrew Morton [this message]
2022-03-09 22:40   ` Minchan Kim

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=20220309140627.eeaa069daa921dbef64f8970@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=cgoldswo@codeaurora.org \
    --cc=joaodias@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=minchan@kernel.org \
    --cc=mtosatti@redhat.com \
    /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