From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: Sleeping function called in invalid context Date: Thu, 4 Aug 2016 18:05:50 +0200 Message-ID: <20160804160550.GA12861@quack2.suse.cz> References: <57A19B9B.60005@kyup.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Theodore Ts'o , Jan Kara , linux-ext4 To: Nikolay Borisov Return-path: Received: from mx2.suse.de ([195.135.220.15]:40799 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964981AbcHDQF6 (ORCPT ); Thu, 4 Aug 2016 12:05:58 -0400 Content-Disposition: inline In-Reply-To: <57A19B9B.60005@kyup.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed 03-08-16 10:22:03, Nikolay Borisov wrote: > While doing some testing on today's checkout of Linus' master branch I > got the following: > > [ 9.302725] BUG: sleeping function called from invalid context at ./include/linux/buffer_head.h:358 > [ 9.304403] in_atomic(): 1, irqs_disabled(): 0, pid: 1718, name: mount > [ 9.305633] 8 locks held by mount/1718: Yeah, this looks like a regression cause by commit 4743f83990614af "ext4: Fix WARN_ON_ONCE in ext4_commit_super()". Arguably that cure is worse than the disease but OTOH calling ext4_commit_super() from an atomic context (like __ext4_grp_locked_error() does) sucks as well. I'm not sure what the right fix is here. The cleanest would probably be to always drop group lock in __ext4_grp_locked_error() and make sure we always properly bail out of mballoc code on such error. But that's a non-trivial amount of work. Not sure if other ext4 people have opinion on this? Honza -- Jan Kara SUSE Labs, CR