From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: Minchan Kim Date: Fri, 16 Nov 2018 07:48:20 -0800 From: Minchan Kim To: Sasha Levin Cc: stable@vger.kernel.org, LKML , Andrew Morton , Sergey Senozhatsky , Hannes Reinecke , Howard Chen Subject: Re: [PATCH] zram: close udev startup race condition as default groups Message-ID: <20181116154820.GA255402@google.com> References: <20181114055223.66476-1-minchan@kernel.org> <20181115174504.GJ95254@sasha-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181115174504.GJ95254@sasha-vm> List-ID: On Thu, Nov 15, 2018 at 12:45:04PM -0500, Sasha Levin wrote: > On Wed, Nov 14, 2018 at 02:52:23PM +0900, Minchan Kim wrote: > > commit fef912bf860e upstream. > > commit 98af4d4df889 upstream. > > > > I got a report from Howard Chen that he saw zram and sysfs race(ie, > > zram block device file is created but sysfs for it isn't yet) > > when he tried to create new zram devices via hotadd knob. > > > > v4.20 kernel fixes it by [1, 2] but it's too large size to merge > > into -stable so this patch fixes the problem by registering defualt > > group by Greg KH's approach[3]. > > > > This patch should be applied to every stable tree [3.16+] currently > > existing from kernel.org because the problem was introduced at 2.6.37 > > by [4]. > > > > [1] fef912bf860e, block: genhd: add 'groups' argument to device_add_disk > > [2] 98af4d4df889, zram: register default groups with device_add_disk() > > [3] http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/ > > [4] 33863c21e69e9, Staging: zram: Replace ioctls with sysfs interface > > > > Cc: Sergey Senozhatsky > > Cc: Hannes Reinecke > > Tested-by: Howard Chen > > Signed-off-by: Minchan Kim > > I've queued this for 4.19 and 4.18, but it doesn't apply to anything > older than that. Thanks for the review, Hannes. Sasha, I will send separate patches for older stable kernel. Thanks for picking the patch. > > -- > Thanks, > Sasha