From: Benjamin LaHaise <bcrl@kvack.org>
To: Sasha Levin <sasha.levin@oracle.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>,
Tang Chen <tangchen@cn.fujitsu.com>,
Dave Jones <davej@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>,
jmoyer@redhat.com, kosaki.motohiro@jp.fujitsu.com,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
miaox@cn.fujitsu.com, linux-aio@kvack.org,
fsdevel <linux-fsdevel@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH] aio: ensure access to ctx->ring_pages is correctly serialised
Date: Tue, 25 Mar 2014 14:57:27 -0400 [thread overview]
Message-ID: <20140325185727.GU4173@kvack.org> (raw)
In-Reply-To: <5331C13C.8030507@oracle.com>
Hi Sasha,
On Tue, Mar 25, 2014 at 01:47:40PM -0400, Sasha Levin wrote:
> On 03/24/2014 03:07 PM, Benjamin LaHaise wrote:
...
> >Yeah, that's a problem -- thanks for the report. The ring_lock mutex can't
> >be nested inside of mmap_sem, as aio_read_events_ring() can take a page
> >fault while holding ring_mutex. That makes the following change required.
> >I'll fold this change into the patch that caused this issue.
>
> Yup, that does the trick.
>
> Could you please add something to document why this is a trylock instead of
> a lock? If
> I were reading the code there's no way I'd understand what's the reason
> behind it
> without knowing of this bug report.
Done. I've updated the patch in my aio-next.git tree, so it should be in
tomorrow's linux-next, and will give it one last day for any further problem
reports. Thanks for testing!
-ben
> Thanks,
> Sasha
--
"Thought is the essence of where you are now."
--
To unsubscribe, send a message with 'unsubscribe linux-aio' in
the body to majordomo@kvack.org. For more info on Linux AIO,
see: http://www.kvack.org/aio/
Don't email: <a href=mailto:"aart@kvack.org">aart@kvack.org</a>
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin LaHaise <bcrl@kvack.org>
To: Sasha Levin <sasha.levin@oracle.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>,
Tang Chen <tangchen@cn.fujitsu.com>,
Dave Jones <davej@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>,
jmoyer@redhat.com, kosaki.motohiro@jp.fujitsu.com,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
miaox@cn.fujitsu.com, linux-aio@kvack.org,
fsdevel <linux-fsdevel@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH] aio: ensure access to ctx->ring_pages is correctly serialised
Date: Tue, 25 Mar 2014 14:57:27 -0400 [thread overview]
Message-ID: <20140325185727.GU4173@kvack.org> (raw)
In-Reply-To: <5331C13C.8030507@oracle.com>
Hi Sasha,
On Tue, Mar 25, 2014 at 01:47:40PM -0400, Sasha Levin wrote:
> On 03/24/2014 03:07 PM, Benjamin LaHaise wrote:
...
> >Yeah, that's a problem -- thanks for the report. The ring_lock mutex can't
> >be nested inside of mmap_sem, as aio_read_events_ring() can take a page
> >fault while holding ring_mutex. That makes the following change required.
> >I'll fold this change into the patch that caused this issue.
>
> Yup, that does the trick.
>
> Could you please add something to document why this is a trylock instead of
> a lock? If
> I were reading the code there's no way I'd understand what's the reason
> behind it
> without knowing of this bug report.
Done. I've updated the patch in my aio-next.git tree, so it should be in
tomorrow's linux-next, and will give it one last day for any further problem
reports. Thanks for testing!
-ben
> Thanks,
> Sasha
--
"Thought is the essence of where you are now."
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin LaHaise <bcrl@kvack.org>
To: Sasha Levin <sasha.levin@oracle.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>,
Tang Chen <tangchen@cn.fujitsu.com>,
Dave Jones <davej@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>,
jmoyer@redhat.com, kosaki.motohiro@jp.fujitsu.com,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>,
miaox@cn.fujitsu.com, linux-aio@kvack.org,
fsdevel <linux-fsdevel@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH] aio: ensure access to ctx->ring_pages is correctly serialised
Date: Tue, 25 Mar 2014 14:57:27 -0400 [thread overview]
Message-ID: <20140325185727.GU4173@kvack.org> (raw)
In-Reply-To: <5331C13C.8030507@oracle.com>
Hi Sasha,
On Tue, Mar 25, 2014 at 01:47:40PM -0400, Sasha Levin wrote:
> On 03/24/2014 03:07 PM, Benjamin LaHaise wrote:
...
> >Yeah, that's a problem -- thanks for the report. The ring_lock mutex can't
> >be nested inside of mmap_sem, as aio_read_events_ring() can take a page
> >fault while holding ring_mutex. That makes the following change required.
> >I'll fold this change into the patch that caused this issue.
>
> Yup, that does the trick.
>
> Could you please add something to document why this is a trylock instead of
> a lock? If
> I were reading the code there's no way I'd understand what's the reason
> behind it
> without knowing of this bug report.
Done. I've updated the patch in my aio-next.git tree, so it should be in
tomorrow's linux-next, and will give it one last day for any further problem
reports. Thanks for testing!
-ben
> Thanks,
> Sasha
--
"Thought is the essence of where you are now."
next prev parent reply other threads:[~2014-03-25 18:57 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-20 5:46 [PATCH 2/2] aio: fix the confliction of read events and migrating ring page Gu Zheng
2014-03-20 5:46 ` Gu Zheng
2014-03-20 14:32 ` Dave Jones
2014-03-20 14:32 ` Dave Jones
2014-03-20 16:30 ` Benjamin LaHaise
2014-03-20 16:30 ` Benjamin LaHaise
2014-03-21 1:56 ` Gu Zheng
2014-03-21 1:56 ` Gu Zheng
2014-03-21 17:35 ` Benjamin LaHaise
2014-03-21 17:35 ` Benjamin LaHaise
2014-03-21 18:35 ` [PATCH] aio: ensure access to ctx->ring_pages is correctly serialised Benjamin LaHaise
2014-03-21 18:35 ` Benjamin LaHaise
2014-03-24 10:56 ` Gu Zheng
2014-03-24 10:56 ` Gu Zheng
2014-03-24 10:59 ` [V2 PATCH 1/2] aio: clean up aio_migratepage() and related code much Gu Zheng
2014-03-24 10:59 ` Gu Zheng
2014-03-24 13:20 ` Benjamin LaHaise
2014-03-24 13:20 ` Benjamin LaHaise
2014-03-25 10:11 ` Gu Zheng
2014-03-24 10:59 ` [V2 PATCH 2/2] aio: fix the confliction of aio read events and aio migrate page Gu Zheng
2014-03-24 10:59 ` Gu Zheng
2014-03-24 18:22 ` [PATCH] aio: ensure access to ctx->ring_pages is correctly serialised Sasha Levin
2014-03-24 18:22 ` Sasha Levin
2014-03-24 19:07 ` Benjamin LaHaise
2014-03-24 19:07 ` Benjamin LaHaise
2014-03-25 17:47 ` Sasha Levin
2014-03-25 17:47 ` Sasha Levin
2014-03-25 18:57 ` Benjamin LaHaise [this message]
2014-03-25 18:57 ` Benjamin LaHaise
2014-03-25 18:57 ` Benjamin LaHaise
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=20140325185727.GU4173@kvack.org \
--to=bcrl@kvack.org \
--cc=akpm@linux-foundation.org \
--cc=davej@redhat.com \
--cc=guz.fnst@cn.fujitsu.com \
--cc=isimatu.yasuaki@jp.fujitsu.com \
--cc=jmoyer@redhat.com \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=kosaki.motohiro@jp.fujitsu.com \
--cc=linux-aio@kvack.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=miaox@cn.fujitsu.com \
--cc=sasha.levin@oracle.com \
--cc=tangchen@cn.fujitsu.com \
--cc=viro@zeniv.linux.org.uk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.