From: Lukas Czerner Subject: Re: [PATCH v2] ext4: ext4_fill_super shouldn't return 0 on corruption Date: Thu, 18 Nov 2010 09:42:57 +0100 (CET) Message-ID: 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 , linux-ext4 To: "Darrick J. Wong" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:27078 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754694Ab0KRInC (ORCPT ); Thu, 18 Nov 2010 03:43:02 -0500 In-Reply-To: <20101116225538.GC18195@tux1.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, 16 Nov 2010, Darrick J. Wong wrote: > On Tue, Nov 16, 2010 at 01:56:31PM +0100, Lukas Czerner wrote: > > On Mon, 15 Nov 2010, 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 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 30ca22c70e3ef0a96ff84de69cd7e8561b416cb2. > > > > > > v2: Return -EFBIG in the error case, per Eric Sandeen's suggestion. > > > > > > Signed-off-by: Darrick J. Wong > > > --- > > > > > > fs/ext4/super.c | 6 +++--- > > > 1 files changed, 3 insertions(+), 3 deletions(-) > > > > > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > > > index 40131b7..120c034 100644 > > > --- a/fs/ext4/super.c > > > +++ b/fs/ext4/super.c > > > @@ -3257,13 +3257,13 @@ 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) > > > ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled"); > > > + ret = -EFBIG; > > > goto failed_mount; > > > } > > > > > > -- > > > 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 > > > > > > > Hi, > > > > 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. > > --D Oh, so you want me to post it as a patch ? Ok, then I'll use the same comment (hope it is ok). Thanks! -Lukas