From: Ted Ts'o Subject: Re: [PATCH v2] ext4: ext4_fill_super shouldn't return 0 on corruption Date: Fri, 19 Nov 2010 09:59:37 -0500 Message-ID: <20101119145936.GD10039@thunk.org> References: <20101115214831.GA18195@tux1.beaverton.ibm.com> <4CE1AC38.9040201@redhat.com> <20101115230346.GB18195@tux1.beaverton.ibm.com> <20101116225538.GC18195@tux1.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Lukas Czerner , Eric Sandeen , "Patrick J. LoPresti" , linux-kernel , linux-ext4 , Mingming Cao To: "Darrick J. Wong" Return-path: Received: from THUNK.ORG ([69.25.196.29]:56228 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755198Ab0KSPlX (ORCPT ); Fri, 19 Nov 2010 10:41:23 -0500 Content-Disposition: inline In-Reply-To: <20101116225538.GC18195@tux1.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Nov 16, 2010 at 02:55:38PM -0800, Darrick J. Wong wrote: > > the untested diff below seems like a more general solution to me, > > since it allows to return the actual error from > > generic_check_addressable(). > > It seems to work ok for me, so: > > Acked-by: Darrick J. Wong > > I will make the same change to ext3. OK, this is what I've added to the ext4 patch queue --- ext4: ext4_fill_super shouldn't return 0 on corruption From: "Darrick J. Wong" At the start of ext4_fill_super, ret is set to -EINVAL, and any failure path out of that function returns ret. However, the generic_check_addressable clause sets ret = 0 (if it passes), which means that a subsequent failure (e.g. a group checksum error) returns 0 even though the mount should fail. This causes vfs_kern_mount in turn to think that the mount succeeded, leading to an oops. A simple fix is to avoid using ret for the generic_check_addressable check, which was last changed in commit 30ca22c70e3. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 61182fe..3d89b72 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3268,13 +3268,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) * Test whether we have more sectors than will fit in sector_t, * and whether the max offset is addressable by the page cache. */ - ret = generic_check_addressable(sb->s_blocksize_bits, + err = generic_check_addressable(sb->s_blocksize_bits, ext4_blocks_count(es)); - if (ret) { + if (err) { ext4_msg(sb, KERN_ERR, "filesystem" " too large to mount safely on this system"); if (sizeof(sector_t) < 8) ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled"); + ret = err; goto failed_mount; }