From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1523458285; cv=none; d=google.com; s=arc-20160816; b=1DHHD5HmOqXzA0LLRqcgkFy5TvwhPlx1vxLDjDqV4T9bTXrkedQIK/vLdsPOeaWdT3 KNNna8YgNkIal52mM86SjLwR0dPnGNE2hby1+nLDqPS0XuZlwpfOgX5I3mYnM+9pVyq5 4B2UVW29MVNEyAc0xROZmWwgeRHMg3TXVviqeiBntxLIyMuVR6ff0BgCCx9VPY0CYwnS /Dj+81xZbAbLj+NrrqNzeoFlQABoK98P00XE0TT1cbZVGjGGH5jahAxV6CJapsC9criE R4EH6JHnK4b1WuLPiCwtbCYgKPyRO13oqV4/MiC+pERnqOw5MYUqs1ja0WFr+BYkZT1l jzkg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:sender:dkim-signature :arc-authentication-results; bh=i9+5GakFxYpJRr7zvzP+WQ4+XZrb0jL0jhJxBrxyCWg=; b=mYCRby6LFIOiq0/r+Ke6nfpFrKU+prJu4qcxLevQKj6kt1ogZkb7J8oCeT2DYQJBBf yTQGAyO+RQmyVuWzvTfOIVOriYth40CJWiJ3vr2D7ryWcn9Lxji0618HDGaa6h5CKJpG Ir9zKWvQr868cIfFp2uAPP91q3+DZ08O+EoupN6XcU0ALfIJhmAw+KYwhYzd4RGeg4lt X+qaFexspSCAnbqRgJClxxhAeJFPo3AtMPxZQzU1ZPTvSVb+bCKD9Qz14y8Kr/SLTyrO eHY3+TkgHtRLtm9AmeN9c4hCtsjV5p7O6n/RT5JVKpLc/3A3Y46gtK6pbZI+Y4bHnKgr Sc8g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=do8jN0eM; spf=pass (google.com: domain of htejun@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=htejun@gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=do8jN0eM; spf=pass (google.com: domain of htejun@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=htejun@gmail.com X-Google-Smtp-Source: AIpwx48bo3pTEyy0aorMxywTZGvj/yM/w1kI4QXgYHAjwffFp1nkRLE4oMvCNk+QH4YADHm8yLZzJA== Sender: Tejun Heo Date: Wed, 11 Apr 2018 07:51:23 -0700 From: Tejun Heo To: Alexandru Moise <00moses.alexander00@gmail.com>, Joseph Qi , Bart Van Assche Cc: axboe@kernel.dk, shli@fb.com, nborisov@suse.com, arnd@arndb.de, gregkh@linuxfoundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] blk-cgroup: remove entries in blkg_tree before queue release Message-ID: <20180411145123.GJ793541@devbig577.frc2.facebook.com> References: <20180407102148.GA9729@gmail.com> <20180409220938.GI3126663@devbig577.frc2.facebook.com> <20180411101242.GA2322@gmail.com> <20180411142019.GG793541@devbig577.frc2.facebook.com> <20180411142859.GB2322@gmail.com> <20180411144616.GI793541@devbig577.frc2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180411144616.GI793541@devbig577.frc2.facebook.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597082451728716242?= X-GMAIL-MSGID: =?utf-8?q?1597461795591401263?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Hello, (cc'ing Bart) On Wed, Apr 11, 2018 at 07:46:16AM -0700, Tejun Heo wrote: > Hello, > > On Wed, Apr 11, 2018 at 04:28:59PM +0200, Alexandru Moise wrote: > > > Ah, that changed recently. Can you please check out the current > > > upstream git master? > > > > > Just did, without my patch I see this crash: > > lol I was looking at the old tree, so this is the fix for the new > breakage introduced by the recent change. Sorry about the confusion. > Joseph, can you please take a look? Oh, it wasn't Joseph's change. It was Bart's fix for a problem reported by Joseph. Bart, a063057d7c73 ("block: Fix a race between request queue removal and the block cgroup controller") created a regression where a request_queue can be destroyed with blkgs still attached. The original report is.. http://lkml.kernel.org/r/20180407102148.GA9729@gmail.com Thanks. -- tejun