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 344C2ECAAA1 for ; Wed, 31 Aug 2022 03:05:34 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-4.v29.lw.sourceforge.com) by sfs-ml-4.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1oTE2l-0004gl-1o; Wed, 31 Aug 2022 03:05:31 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-4.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oTE2k-0004ge-6F for linux-f2fs-devel@lists.sourceforge.net; Wed, 31 Aug 2022 03:05:30 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=In-Reply-To:Content-Type:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding: 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=fiU+T4aq9Zqm/GX0PZIUwWGsMdUHVXCSO6SbM+9PwdI=; b=A1A3xX4zSQSkiCxk4Uinkec6He q62uAxV5i16Ny/7OyM8FJfuLp1FG3uDU4eVGVvpVDQxjKhne/bQlwLRgnmzzEWFYYWuaVFpY+i1US A9hUV9HyRSfv+foPv25sS6ZntzP5lrvbOZWV6xr2x0yk4oZYvKvn2KtF1YSNShpRvAb0=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To :From:Date:Sender:Reply-To:Content-Transfer-Encoding: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=fiU+T4aq9Zqm/GX0PZIUwWGsMdUHVXCSO6SbM+9PwdI=; b=DaozGKgUBzgIwUwpVNjZoRPnP1 kLnNxU8ff/f9F41/kAeCjDTiQs54afayCI1xSJXs6r1aNW6rAUQAAsQ+uJ7zmZS2zrlIEL+4YfKyD C5xb844/eZs88riS5iAv6oQNe2EwMw9z/d+d9UzT2FoyU5i7rjH5aN/h/SUeQ49H/9gU=; 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 1oTE2e-0005Me-TH for linux-f2fs-devel@lists.sourceforge.net; Wed, 31 Aug 2022 03:05:30 +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 B468761927; Wed, 31 Aug 2022 03:05:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00040C433D6; Wed, 31 Aug 2022 03:05:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661915114; bh=dVup0T/Gm724oVjCg6gv0zTexmWsoNH4XnK67lgI7vE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bQ30ftyUYj4WNesdVZUK9vAqMkE3skgwTYdXxXPOBfBzazE8a93xVE4JGmbGcPvEb PB6qBqbBZaTTb21dHtzVekH9LPpziKxNQF9fLI9dQFsVqicqg3Hly3XL95+KA6dLp+ brMfAWgTDhPNB8aogrWkaTA/qO5fXLC5/7+qk8SuoVzSY9nUqYkywc5Cu+hkKNkI4v NOV5W8zpZ47zcxAtHwfkyICuzMvzhGLdOpy9eR2RgH5hR8qsRYmYroiEUvX5P8Hyqc Rl2XWH8wLl4ivgj/a3Z7tepiOmLG7lhvBr98cOs7BaxVL5B42V5xi9NkbXu9kmtH7M Su6HC6623/5mQ== Date: Tue, 30 Aug 2022 20:05:12 -0700 From: Jaegeuk Kim To: Chao Yu Message-ID: References: <20220829215206.3082124-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Headers-End: 1oTE2e-0005Me-TH 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net 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 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