Re: [PATCH] ext4: add fallocate mode blocking for debugging purposes

["Lukáš Czerner" <lczerner@redhat.com>]

On Mon, 14 Apr 2014, Namjae Jeon wrote:

> Date: Mon, 14 Apr 2014 23:05:47 +0900
> From: Namjae Jeon <linkinjeon@gmail.com>
> To: Theodore Ts'o <tytso@mit.edu>
> Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>
> Subject: Re: [PATCH] ext4: add fallocate mode blocking for debugging purposes
> 
> >
> > Hi Namjae,
> >
> > One of the reasons this patch set is that after Lukas added
> > COLLAPSE_RANGE support into fsx, we've started seeing a number of
> > failures which seem to be directly related to COLLAPSE_RANGE.
> >
> > For your convenience, I've updated the root_fs.img file for the
> > kvm-xfststs system in the xfstests-bld system:
> >
> > https://www.kernel.org/pub/linux/kernel/people/tytso/kvm-xfstests/root_fs.img.i386
> >
> > This has the latest xfstests (plus some bug fixes not yet in the
> > xfstests upstream), which means it has the improved fsx.  With this
> > updated xfstests, the tests which use fsx, such as generic/075 and
> > generic/091, are failing for the 1k and bigalloc configuration, and if
> > we apply this patch and then add to the kernel's boot command line:
> >
> >    ext4.fallocate_mode_block=0x08
> >
> > this will allow these tests to pass again.
> >
> > (An easy way to do this using kvm-xfstests is by creating the file
> > custom.config with the line "EXTRA_ARG="ext4.fallocate_mode_block=0x08")
> >
> >
> > In addition, although I haven't figured out why what is needed to
> > create a reliable production, test generic/091 (with COLLAPSE_RANGE
> > enabled) is sometimes causing a file system corruption which causes
> > the xfstests run to abort.  (It does seem to reproduce more reliably
> > if generic/091 is run as part of a "-g auto" run):
> >
> > e2fsck 1.42.9 (4-Feb-2014)
> > Pass 1: Checking inodes, blocks, and sizes
> > Inode 20 has out of order extents
> > 	(invalid logical block 3, physical block 492938, len 2)
> > Clear? yes
> >
> > Inode 20, i_blocks is 368, should be 352.  Fix? yes
> >
> > Pass 2: Checking directory structure
> > Pass 3: Checking directory connectivity
> > Pass 4: Checking reference counts
> > Pass 5: Checking group summary information
> > Block bitmap differences:  -(492938--492939)
> > Fix? yes
> >
> > Free blocks count wrong for group #15 (32657, counted=32659).
> > Fix? yes
> >
> > Free blocks count wrong (1136513, counted=1136515).
> > Fix? yes
> >
> >
> > /dev/vdb: ***** FILE SYSTEM WAS MODIFIED *****
> > /dev/vdb: 10137/327680 files (5.4% non-contiguous), 174205/1310720 blocks
> >
> > (This was found in the standard 4k configuration, but in the test log
> > below it was showing up in the dioread_nolock configuration).
> >
> > If you could take a look at some of these test failures, I'd be much
> > obliged.
> Hi. Ted.
> I will take a look at this issue.
> Thanks for your mail!

Hi,

Just a heads up for those working on the fix for this problem.
I've got the fix and I am testing it right now. Will send patches
soon after I verify that it's working properly. 

Thanks!
-Lukas

> >
> > Thanks!
> >
> > 						- Ted
> >
> --
> 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
>