From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
Cc: Josh Boyer
<jwboyer-rxtnV0ftBwyoClj4AeEUq9i2O/JbrIOy@public.gmane.org>,
Jeff Moyer <jmoyer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
msnitzer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
"Linux-Kernel@Vger. Kernel. Org"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"Richard W.M. Jones"
<rjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH block/for-linus] block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
Date: Tue, 8 Sep 2015 11:31:32 -0400 [thread overview]
Message-ID: <20150908153132.GD13749@mtj.duckdns.org> (raw)
In-Reply-To: <20150905194736.GB8231-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
On Sat, Sep 05, 2015 at 03:47:36PM -0400, Tejun Heo wrote:
> While making the root blkg unconditional, ec13b1d6f0a0 ("blkcg: always
> create the blkcg_gq for the root blkcg") removed the part which clears
> q->root_blkg and ->root_rl.blkg during q exit. This leaves the two
> pointers dangling after blkg_destroy_all(). blk-throttle exit path
> performs blkg traversals and dereferences ->root_blkg and can lead to
> the following oops.
Jens, can you please route this one w/ Richard's tested-by added?
Thanks!
--
tejun
next prev parent reply other threads:[~2015-09-08 15:31 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-30 12:30 __blkg_lookup oops with 4.2-rcX Josh Boyer
2015-08-30 18:04 ` Richard W.M. Jones
2015-09-02 14:53 ` Tejun Heo
[not found] ` <20150902145307.GG22326-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
2015-09-02 15:32 ` Tejun Heo
2015-09-04 10:46 ` Richard W.M. Jones
[not found] ` <20150904104602.GN29283-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-09-04 17:13 ` Tejun Heo
[not found] ` <20150904171302.GE25329-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
2015-09-04 18:17 ` Richard W.M. Jones
2015-09-04 20:42 ` Richard W.M. Jones
2015-09-05 15:34 ` Richard W.M. Jones
[not found] ` <20150905153439.GA18461-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-09-05 15:48 ` Richard W.M. Jones
[not found] ` <20150905154840.GA19460-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-09-05 18:38 ` Tejun Heo
[not found] ` <20150905183801.GA8231-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
2015-09-05 19:47 ` [PATCH block/for-linus] block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg Tejun Heo
2015-09-06 8:30 ` Richard W.M. Jones
[not found] ` <20150905194736.GB8231-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
2015-09-08 15:31 ` Tejun Heo [this message]
2015-09-08 15:35 ` Jens Axboe
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