linux-kernel - Re: [PATCH v4 0/7] blk-mq: fix race conditions on cpu hotplug handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 29 Sep 2015 11:31:52 -0600
From:	Jens Axboe <axboe@...nel.dk>
To:	Akinobu Mita <akinobu.mita@...il.com>, linux-kernel@...r.kernel.org
Cc:	Ming Lei <tom.leiming@...il.com>, Tejun Heo <tj@...nel.org>,
	Keith Busch <keith.busch@...el.com>,
	Christoph Hellwig <hch@....de>,
	Wanpeng Li <wanpeng.li@...mail.com>
Subject: Re: [PATCH v4 0/7] blk-mq: fix race conditions on cpu hotplug
 handling

On 09/26/2015 11:09 AM, Akinobu Mita wrote:
> This patchset addresses several race conditions on cpu hotplug handling
> for blk-mq.  All problems can be reproducible by the following script.
>
> while true; do
> 	echo 0 > /sys/devices/system/cpu/cpu1/online
> 	echo 1 > /sys/devices/system/cpu/cpu1/online
> done &
>
> while true; do
> 	modprobe -r null_blk
> 	modprobe null_blk queue_mode=2 irqmode=1
> 	sleep 0.1
> done
>
> * Changes from v3
> - Rebased to the latest kernel
> - Add Reviewed-by tags

I've reviewed the patches, looks good to me. I've skipped 6/7, as I 
think we should fix that as part of the percpu ref counting, and not 
handle it specifically in blk-mq. If we can't get that fix before 4.3 
wraps up, then we can revisit and put that in as well.

Thanks!

-- 
Jens Axboe

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/