From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Darrick J. Wong" Subject: Re: [PATCH] ext4: disable defrag for metadata_csum file systems Date: Thu, 18 Apr 2013 22:47:38 -0700 Message-ID: <20130419054738.GA5617@blackbox.djwong.org> References: <1366322282-4673-1-git-send-email-tytso@mit.edu> <51707E06.2050105@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Theodore Ts'o" , Ext4 Developers List To: Zheng Liu Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:31814 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752597Ab3DSFrp (ORCPT ); Fri, 19 Apr 2013 01:47:45 -0400 Content-Disposition: inline In-Reply-To: <51707E06.2050105@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Apr 19, 2013 at 07:13:10AM +0800, Zheng Liu wrote: > [Sorry, it seems that I got a delivery error. So send again] > > On 04/19/2013 05:58 AM, Theodore Ts'o wrote: > > It looks like there is absolutely no support for metadata checksums in > > fs/ext4/move_extent.c. So if you try to defrag a file on a > > metadata_csum, it leaves the file system corrupted. > > > > We really, really should get this fixed ASAP, but until we do, let's > > disable e4defrag on metadata_csum file systems so we avoid corrupting > > file systems. > > > > Cc: "Darrick J. Wong" > > Signed-off-by: "Theodore Ts'o" > > Yes, I also notice this problem. So currently it seems that the best > choice is to disable defrag for metadata_csum. I think this happens because mext_insert_extents() open-codes the metadata dirtying and forgets to update the extent block header. It should call ext4_ext_dirty() at the end, instead. :( I should see if there are any other sites that dirty metadata without making the proper csum_set calls. Will send a fix shortly, so NAK. --D > > Reviewed-By: Zheng Liu > > Thanks, > - Zheng > > > --- > > fs/ext4/ioctl.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c > > index 9491ac0..2d043da 100644 > > --- a/fs/ext4/ioctl.c > > +++ b/fs/ext4/ioctl.c > > @@ -450,6 +450,15 @@ group_extend_out: > > goto mext_out; > > } > > > > + if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, > > + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) { > > + ext4_msg(sb, KERN_ERR, > > + "Online defrag not supported with " > > + "metadata_csum"); > > + err = -EOPNOTSUPP; > > + goto mext_out; > > + } > > + > > err = mnt_want_write_file(filp); > > if (err) > > goto mext_out; > > > > -- > 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