From: Eric Sandeen Subject: Re: [PATCH] ext4: ext4_fill_super shouldn't return 0 on corruption Date: Mon, 15 Nov 2010 15:55:04 -0600 Message-ID: <4CE1AC38.9040201@redhat.com> References: <20101115214831.GA18195@tux1.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Theodore Ts'o" , "Patrick J. LoPresti" , linux-kernel , linux-ext4 , Mingming Cao To: djwong@us.ibm.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:56501 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755605Ab0KOVzV (ORCPT ); Mon, 15 Nov 2010 16:55:21 -0500 In-Reply-To: <20101115214831.GA18195@tux1.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 11/15/10 3:48 PM, Darrick J. Wong wrote: > At the start of ext4_fill_super, ret is set to -EINVAL, and any failure path > out of that function returns this 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 (because > PTR_ERR(0) is false), leading to an oops. > > A simple fix is to avoid using ret for the generic_check_addressable check, > which was last changed in commit 30ca22c70e3ef0a96ff84de69cd7e8561b416cb2. > > Signed-off-by: Darrick J. Wong looks right, but one comment below: > --- > > fs/ext4/super.c | 5 ++--- > 1 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 40131b7..a44bc59 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3257,9 +3257,8 @@ 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, > - ext4_blocks_count(es)); > - if (ret) { > + if (generic_check_addressable(sb->s_blocksize_bits, > + ext4_blocks_count(es))) { > ext4_msg(sb, KERN_ERR, "filesystem" > " too large to mount safely on this system"); > if (sizeof(sector_t) < 8) you probably want to set a "ret = -EFBIG" in here. -Eric > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html