Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4882DC64ED6 for ; Wed, 1 Mar 2023 12:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbjCAMnJ (ORCPT ); Wed, 1 Mar 2023 07:43:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229659AbjCAMmx (ORCPT ); Wed, 1 Mar 2023 07:42:53 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2730D103; Wed, 1 Mar 2023 04:42:51 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id A994521A81; Wed, 1 Mar 2023 12:42:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1677674569; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Lsv1DuXMnRsAXWN1/iMg2zCHw6wIP8mEYOtvYwGdNCU=; b=hT6F6gfxlhGLyH4lFvA8/XrwgfMxpIpX7voqeaDOHacYJEQFoqCjdseLrVa9Gh1AIT2AyS vv1wLQRR/w0VAdEX/8nt4V7Rvqy6lyJD/Yl3O3M0sUyyaPXsolE5kWTU6UTOrN9tNwUsd3 HJ0BkFcr+gDBISQkpOShRCC+nEmm2uU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1677674569; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Lsv1DuXMnRsAXWN1/iMg2zCHw6wIP8mEYOtvYwGdNCU=; b=oUQI3h05w/jZ2zPFPeJWyGpmk6PwrqMi7r8hpPIT5cgG9ykEsmZ+ts6yEUTNVyFdM1ahd1 yV5ttFU9eeGODvAg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 9C22613A63; Wed, 1 Mar 2023 12:42:49 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id GagLJklI/2PaeAAAMHmgww (envelope-from ); Wed, 01 Mar 2023 12:42:49 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id 2877EA06E5; Wed, 1 Mar 2023 13:42:49 +0100 (CET) Date: Wed, 1 Mar 2023 13:42:49 +0100 From: Jan Kara To: syzbot Cc: hdanton@sina.com, jack@suse.com, jack@suse.cz, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tytso@mit.edu Subject: Re: [syzbot] [ext4?] possible deadlock in jbd2_log_wait_commit Message-ID: <20230301124249.tj7oub3r35q5z3rx@quack3> References: <00000000000052865105f5c8f2c8@google.com> <0000000000003845ba05f5d3e416@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0000000000003845ba05f5d3e416@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed 01-03-23 02:08:19, syzbot wrote: > syzbot has bisected this issue to: > > commit 0813299c586b175d7edb25f56412c54b812d0379 > Author: Jan Kara > Date: Thu Jan 26 11:22:21 2023 +0000 > > ext4: Fix possible corruption when moving a directory > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14845d50c80000 > start commit: e492250d5252 Merge tag 'pwm/for-6.3-rc1' of git://git.kern.. > git tree: upstream > final oops: https://syzkaller.appspot.com/x/report.txt?x=16845d50c80000 > console output: https://syzkaller.appspot.com/x/log.txt?x=12845d50c80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f763d89e26d3d4c4 > dashboard link: https://syzkaller.appspot.com/bug?extid=9d16c39efb5fade84574 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d96208c80000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=176d917f480000 > > Reported-by: syzbot+9d16c39efb5fade84574@syzkaller.appspotmail.com > Fixes: 0813299c586b ("ext4: Fix possible corruption when moving a directory") > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection Drat, yeah, lockdep is actually right. We should not be grabbing i_rwsem while having transaction started in ext4_rename(). I'm somewhat surprised we didn't hit this lockdep warning earlier during the testing. So we need to move the locking earlier in ext4_rename(). I'll send a patch... Honza -- Jan Kara SUSE Labs, CR