Re: [PATCH] ext4/004: add dump/restore test

From: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
To: Theodore Ts'o <tytso@mit.edu>
Cc: fstests@vger.kernel.org, linux-ext4@vger.kernel.org,
	Dave Chinner <david@fromorbit.com>
Subject: Re: [PATCH] ext4/004: add dump/restore test
Date: Wed, 17 Dec 2014 13:16:27 +0800	[thread overview]
Message-ID: <549111AB.60108@cn.fujitsu.com> (raw)
In-Reply-To: <20141216025827.GO17575@thunk.org>

Hi,

On 12/16/2014 10:58 AM, Theodore Ts'o wrote:
> On Mon, Dec 08, 2014 at 09:44:48AM +0800, Xiaoguang Wang wrote:
>>
>> Yeah, my intent is to test dump/restore program, and indeed I imitate that
>> how xfs to test xfsdump/xfsrestore, xfs puts xfsdump/xfsrestore tests in
>> corresponding xfs directory.
> 
> I'm finding that the test takes 6-7 minutes to run, partially because
> it's writing close to half a gigabyte worth of data for the
> dump/restore.  Is this really necessary?  Can we perhaps cut down the
> amount of data generated by running fsstress?  The time to run the
> full set of tests is taking longer and longer, and one answer might be
> that for tests that are irrelevant for kernel and which take a long
> time, I'll just supress them in my test runs.  But maybe we can just
> significantly cut back the amount of data to be backed up and
> restored?  How much do we really need to create in order for you to
> feel that you've adequately tested dump/restore?

I choose to make a 512MB file system and the arguments "-z -f creat=5 -f write=20
-f mkdir=5 -n 1000 -p 15" is to make sure that the dump operation would be against
a full file system. I have read your patch "ext4/004: limit the amount of data written
so test runs faster", it looks OK to me, sorry for the bothering.

> 
> And I'll note that using the current fsstress arguments, you are only
> creating regular files and directories, and there are no symlinks,
> device nodes, or FIFO's being created to test whether those files are
> correctly being backed up and restored.

Yeah, I skipped these special files deliberately. Originally I used the arguments
"-n 1000 -p 15". In RHEL7.0GA, restore tool will trigger a segmentation fault,
the call trace is:
---------------------------------------------------------------------
Program terminated with signal 11, Segmentation fault.
#0  0x000000000040df24 in readxattr ()
...
(gdb) bt
#0  0x000000000040df24 in readxattr ()
#1  0x000000000040e160 in extractattr ()
#2  0x000000000040e4e2 in extractfile ()
#3  0x00000000004097b0 in createleaves ()
#4  0x0000000000403ae6 in main ()
--------------------------------------------------------------------- 
The dump/restore version is 0.4b44, which is already latest. I have sent a bug
report to Stelian Pop, maintainer of dump/restore. Later if this issue is fixed,
I'll send patch to improve this 004 case, let it handle types of files, sorry.

Regards,
Xiaoguang Wang 
> 
> Cheers,
> 
> 						- Ted
> .
>