Re: [PATCH 1/9] ext4/003: Fix this test on 64K platform for dax config

From: Ritesh Harjani <riteshh@linux.ibm.com>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: fstests@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 1/9] ext4/003: Fix this test on 64K platform for dax config
Date: Thu, 8 Jul 2021 11:54:45 +0530	[thread overview]
Message-ID: <20210708062445.xnoij6ya7huedqcv@riteshh-domain> (raw)
In-Reply-To: <YNybadzpnZZdwtzR@mit.edu>

On 21/06/30 12:27PM, Theodore Ts'o wrote:
> On Mon, Jun 14, 2021 at 11:58:05AM +0530, Ritesh Harjani wrote:
> > mkfs.ext4 by default uses 4K blocksize which doesn't mount when testing
> > with dax config and the test fails. This patch fixes it.
> >
> > Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
> > ---
> >  tests/ext4/003 | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tests/ext4/003 b/tests/ext4/003
> > index 00ea9150..1ddb3063 100755
> > --- a/tests/ext4/003
> > +++ b/tests/ext4/003
> > @@ -31,7 +31,8 @@ _require_scratch_ext4_feature "bigalloc"
> >
> >  rm -f $seqres.full
> >
> > -$MKFS_EXT4_PROG -F -O bigalloc -C 65536  -g 256 $SCRATCH_DEV 512m \
> > +BLOCK_SIZE=$(get_page_size)
> > +$MKFS_EXT4_PROG -F -b $BLOCK_SIZE -O bigalloc -C 65536  -g 256 $SCRATCH_DEV 512m \
> >  	>> $seqres.full 2>&1
> >  _scratch_mount
>
> Thanks for the patch!

Thanks for the review, sorry about the delay (- Last week was short a week for
me).

>
> If the block size is 64k, then the cluster_size == block_size at which
> point ext4/003 won't be able to test for the regression its designed
> to test.  So we probably need to scale the cluster size and file
> system size relative to the block size.

Yes, thanks for catching it. I think if make below change, i.e. scale cluster
size, we should be good. Since this will make blocks_per_group = 4096 and
clusters_per_group = 256. This is the condition, which I guess the original
kernel patch fixed it for. So, we need not increase the filesystem size.

$MKFS_EXT4_PROG -F -b $BLOCK_SIZE -O bigalloc -C $((BLOCK_SIZE * 16))  -g 256 $SCRATCH_DEV 512m \

-ritesh

>
> 					- Ted