From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6C3E9C6FA82 for ; Wed, 14 Sep 2022 15:28:49 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1oYUJj-0006vy-Qp; Wed, 14 Sep 2022 15:28:47 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oYUJj-0006vr-Dw for linux-f2fs-devel@lists.sourceforge.net; Wed, 14 Sep 2022 15:28:47 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=pK50lrmyMrxfNGbcZi+3dCJR1eU+uy40kot/huY+JiY=; b=bwmLZU4w3l9GbeHvsj17ofpktF a1B37U0nCX501dyD5o4JGoLFBJ4CYnrSdleXmiLAVv2VrMp0QHBeIKzADkVujG0cp2XTTOFb4iiok jppaK3OCG0BclKaldYdpwN7kUquOIJS6MhqWa+mFBmG4661ed31/O6JPyoWg8bh5HEPU=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=pK50lrmyMrxfNGbcZi+3dCJR1eU+uy40kot/huY+JiY=; b=l/riB2ux78m+ErN05ehCHNpusZ syUHM0llh97qOhRpOOacGnXldy0us3chAwEEX8odZ2kIrBJmnz9+OBKrYUpn9nOmuie0e/qhLQEnC QAEd7YOUrBcDo64nh2zgoMtb5M++1FKIRifTlqeRkhfn6m0nQObJ6L/YMmaY19jFPQRI=; Received: from dfw.source.kernel.org ([139.178.84.217]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1oYUJd-0000Hs-LD for linux-f2fs-devel@lists.sourceforge.net; Wed, 14 Sep 2022 15:28:47 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 338E661480; Wed, 14 Sep 2022 15:28:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A7C2C433C1; Wed, 14 Sep 2022 15:28:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663169315; bh=zqphwVveYBXH6VOdrvrXdJKfcphlsHIz/gl20fLq9co=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=k843nBZnznsTAagoZV3QB2AMK+NShGqK0WJA6yzKqX6b/9/jb1+lcugXP31UBDJ9j SrwPHXBaUGr2cJpGBJ9dVz0yyYxVqH1iZYIOCu8cLyUj1nsTYjV1N+Jjnogddj+VeV EaNHfRA1gPHabRxaVv/iR4rpumktEIHHboYoGfg+3Pb+ddix6cZ/O44sve2rfN5p+H uT9+cEKPPQoVQzKcNYbhq8v+AWVQU+gXd5KMr15nyOT5fvf9l6blTrhYgrVLsoWfUZ og3+vvlccx0F7VYHS+3fE93rCbz8Kds4AC+x7UupSZ8pPAf9nC+48BE3sOz6YvYLyi +xOP6lc1pGGww== Message-ID: Date: Wed, 14 Sep 2022 23:28:31 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Content-Language: en-US To: Jaegeuk Kim References: <20220829215206.3082124-1-jaegeuk@kernel.org> <2b669973-caf0-75e8-f421-7647dddf03ce@kernel.org> From: Chao Yu In-Reply-To: X-Headers-End: 1oYUJd-0000Hs-LD Subject: Re: [f2fs-dev] [PATCH] f2fs: fix missing mapping caused by the mount/umount race X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 2022/9/14 23:15, Jaegeuk Kim wrote: > On 09/14, Chao Yu wrote: >> On 2022/8/31 11:05, Jaegeuk Kim wrote: >>> On 08/30, Jaegeuk Kim wrote: >>>> On 08/30, Chao Yu wrote: >>>>> On 2022/8/30 5:52, Jaegeuk Kim wrote: >>>>>> Sometimes we can get a cached meta_inode which has no aops yet. Let's set it >>>>>> all the time to fix the below panic. >>>>>> >>>>>> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 >>>>>> Mem abort info: >>>>>> ESR = 0x0000000086000004 >>>>>> EC = 0x21: IABT (current EL), IL = 32 bits >>>>>> SET = 0, FnV = 0 >>>>>> EA = 0, S1PTW = 0 >>>>>> FSC = 0x04: level 0 translation fault >>>>>> user pgtable: 4k pages, 48-bit VAs, pgdp=0000000109ee4000 >>>>>> [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 >>>>>> Internal error: Oops: 86000004 [#1] PREEMPT SMP >>>>>> Modules linked in: >>>>>> CPU: 1 PID: 3045 Comm: syz-executor330 Not tainted 6.0.0-rc2-syzkaller-16455-ga41a877bc12d #0 >>>>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 >>>>>> pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>>>>> pc : 0x0 >>>>>> lr : folio_mark_dirty+0xbc/0x208 mm/page-writeback.c:2748 >>>>>> sp : ffff800012783970 >>>>>> x29: ffff800012783970 x28: 0000000000000000 x27: ffff800012783b08 >>>>>> x26: 0000000000000001 x25: 0000000000000400 x24: 0000000000000001 >>>>>> x23: ffff0000c736e000 x22: 0000000000000045 x21: 05ffc00000000015 >>>>>> x20: ffff0000ca7403b8 x19: fffffc00032ec600 x18: 0000000000000181 >>>>>> x17: ffff80000c04d6bc x16: ffff80000dbb8658 x15: 0000000000000000 >>>>>> x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 >>>>>> x11: ff808000083e9814 x10: 0000000000000000 x9 : ffff8000083e9814 >>>>>> x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 >>>>>> x5 : ffff0000cbb19000 x4 : ffff0000cb3d2000 x3 : ffff0000cbb18f80 >>>>>> x2 : fffffffffffffff0 x1 : fffffc00032ec600 x0 : ffff0000ca7403b8 >>>>>> Call trace: >>>>>> 0x0 >>>>>> set_page_dirty+0x38/0xbc mm/folio-compat.c:62 >>>>>> f2fs_update_meta_page+0x80/0xa8 fs/f2fs/segment.c:2369 >>>>>> do_checkpoint+0x794/0xea8 fs/f2fs/checkpoint.c:1522 >>>>>> f2fs_write_checkpoint+0x3b8/0x568 fs/f2fs/checkpoint.c:1679 >>>>>> >>>>>> Cc: stable@vger.kernel.org >>>>>> Reported-by: syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com >>>>>> Signed-off-by: Jaegeuk Kim >>>>>> --- >>>>>> fs/f2fs/inode.c | 13 ++++++++----- >>>>>> 1 file changed, 8 insertions(+), 5 deletions(-) >>>>>> >>>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >>>>>> index 6d11c365d7b4..1feb0a8a699e 100644 >>>>>> --- a/fs/f2fs/inode.c >>>>>> +++ b/fs/f2fs/inode.c >>>>>> @@ -490,10 +490,7 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino) >>>>>> if (!inode) >>>>>> return ERR_PTR(-ENOMEM); >>>>>> - if (!(inode->i_state & I_NEW)) { >>>>>> - trace_f2fs_iget(inode); >>>>>> - return inode; >>>>>> - } >>>>>> + /* We can see an old cached inode. Let's set the aops all the time. */ >>>>> >>>>> Why an old cached inode (has no I_NEW flag) has NULL a_ops pointer? If it is a bad >>>>> inode, it should be unhashed before unlock_new_inode(). >>>> >>>> I'm trying to dig further tho, it's not a bad inode, nor I_FREEING | I_CLEAR. >>>> It's very werid that thie meta inode is found in newly created superblock by >>>> the global hash table. I've checked that the same superblock pointer was used >>>> in the previous tests, but inode was evictied all the time. >>> >>> I'll drop this patch, since it turned out there is a bug in reiserfs which >>> doesn't free the root inode (ino=2). That leads f2fs to find an ino=2 with >>> the previous superblock point used by reiserfs. That stale inode has no valid >> >> One more question, why stale inode could be remained in inode hash table, >> shouldn't the stale inode be evicted/unhashed in below path during reiserfs >> umount: >> >> - reiserfs_kill_sb >> - kill_block_super >> - generic_shutdown_super >> - evict_inodes >> - dispose_list >> - evict >> - remove_inode_hash > > Yes, that's why I didn't dive into further, as it's odd. Alright, this bug was reproducable w/ below testcase, right? :) C reproducer: https://syzkaller.appspot.com/x/repro.c?x=167b5e33080000 Thanks, > >> >> Thanks, >> >>> inode that f2fs can use. I tried to find where the root cause is in reiserfs, >>> but it seems quite hard to catch one. >>> >>> - reiserfs_fill_super >>> - reiserfs_xattr_init >>> - create_privroot >>> - xattr_mkdir >>> - reiserfs_new_inode >>> - reiserfs_get_unused_objectid returned 0 due to map crash >>> >>> It seems the error path doesn't handle the root inode properly. >>> >>>> >>>>> >>>>> Thanks, >>>>> >>>>>> if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi)) >>>>>> goto make_now; >>>>>> @@ -502,6 +499,11 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino) >>>>>> goto make_now; >>>>>> #endif >>>>>> + if (!(inode->i_state & I_NEW)) { >>>>>> + trace_f2fs_iget(inode); >>>>>> + return inode; >>>>>> + } >>>>>> + >>>>>> ret = do_read_inode(inode); >>>>>> if (ret) >>>>>> goto bad_inode; >>>>>> @@ -557,7 +559,8 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino) >>>>>> file_dont_truncate(inode); >>>>>> } >>>>>> - unlock_new_inode(inode); >>>>>> + if (inode->i_state & I_NEW) >>>>>> + unlock_new_inode(inode); >>>>>> trace_f2fs_iget(inode); >>>>>> return inode; >>>> >>>> >>>> _______________________________________________ >>>> Linux-f2fs-devel mailing list >>>> Linux-f2fs-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel