Re: [PATCH v2] check: Fix fs specfic imports when $FSTYPE!=$OLD_FSTYPE

["Nirjhar Roy (IBM)" <nirjhar.roy.lists@gmail.com>]

On 1/31/25 21:54, Darrick J. Wong wrote:
> On Fri, Jan 31, 2025 at 06:49:50PM +0530, Nirjhar Roy (IBM) wrote:
>> On 1/29/25 21:32, Darrick J. Wong wrote:
>>> On Wed, Jan 29, 2025 at 04:48:10PM +0530, Nirjhar Roy (IBM) wrote:
>>>> On 1/28/25 23:39, Darrick J. Wong wrote:
>>>>> On Tue, Jan 28, 2025 at 05:00:22AM +0000, Nirjhar Roy (IBM) wrote:
>>>>>> Bug Description:
>>>>>>
>>>>>> _test_mount function is failing with the following error:
>>>>>> ./common/rc: line 4716: _xfs_prepare_for_eio_shutdown: command not found
>>>>>> check: failed to mount /dev/loop0 on /mnt1/test
>>>>>>
>>>>>> when the second section in local.config file is xfs and the first section
>>>>>> is non-xfs.
>>>>>>
>>>>>> It can be easily reproduced with the following local.config file
>>>>>>
>>>>>> [s2]
>>>>>> export FSTYP=ext4
>>>>>> export TEST_DEV=/dev/loop0
>>>>>> export TEST_DIR=/mnt1/test
>>>>>> export SCRATCH_DEV=/dev/loop1
>>>>>> export SCRATCH_MNT=/mnt1/scratch
>>>>>>
>>>>>> [s1]
>>>>>> export FSTYP=xfs
>>>>>> export TEST_DEV=/dev/loop0
>>>>>> export TEST_DIR=/mnt1/test
>>>>>> export SCRATCH_DEV=/dev/loop1
>>>>>> export SCRATCH_MNT=/mnt1/scratch
>>>>>>
>>>>>> ./check selftest/001
>>>>>>
>>>>>> Root cause:
>>>>>> When _test_mount() is executed for the second section, the FSTYPE has
>>>>>> already changed but the new fs specific common/$FSTYP has not yet
>>>>>> been done. Hence _xfs_prepare_for_eio_shutdown() is not found and
>>>>>> the test run fails.
>>>>>>
>>>>>> Fix:
>>>>>> Remove the additional _test_mount in check file just before ". commom/rc"
>>>>>> since ". commom/rc" is already sourcing fs specific imports and doing a
>>>>>> _test_mount.
>>>>>>
>>>>>> Fixes: 1a49022fab9b4 ("fstests: always use fail-at-unmount semantics for XFS")
>>>>>> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
>>>>>> ---
>>>>>>     check | 12 +++---------
>>>>>>     1 file changed, 3 insertions(+), 9 deletions(-)
>>>>>>
>>>>>> diff --git a/check b/check
>>>>>> index 607d2456..5cb4e7eb 100755
>>>>>> --- a/check
>>>>>> +++ b/check
>>>>>> @@ -784,15 +784,9 @@ function run_section()
>>>>>>     			status=1
>>>>>>     			exit
>>>>>>     		fi
>>>>>> -		if ! _test_mount
>>>>> Don't we want to _test_mount the newly created filesystem still?  But
>>>>> perhaps after sourcing common/rc ?
>>>>>
>>>>> --D
>>>> common/rc calls init_rc() in the end and init_rc() already does a
>>>> _test_mount. _test_mount after sourcing common/rc will fail, won't it? Does
>>>> that make sense?
>>>>
>>>> init_rc()
>>>> {
>>>>       # make some further configuration checks here
>>>>       if [ "$TEST_DEV" = ""  ]
>>>>       then
>>>>           echo "common/rc: Error: \$TEST_DEV is not set"
>>>>           exit 1
>>>>       fi
>>>>
>>>>       # if $TEST_DEV is not mounted, mount it now as XFS
>>>>       if [ -z "`_fs_type $TEST_DEV`" ]
>>>>       then
>>>>           # $TEST_DEV is not mounted
>>>>           if ! _test_mount
>>>>           then
>>>>               echo "common/rc: retrying test device mount with external set"
>>>>               [ "$USE_EXTERNAL" != "yes" ] && export USE_EXTERNAL=yes
>>>>               if ! _test_mount
>>>>               then
>>>>                   echo "common/rc: could not mount $TEST_DEV on $TEST_DIR"
>>>>                   exit 1
>>>>               fi
>>>>           fi
>>>>       fi
>>>> ...
>>> ahahahaha yes it does.
>>>
>>> /commit message reading comprehension fail, sorry about that.
>>>
>>> Though now that you point it out, should check elide the init_rc call
>>> about 12 lines down if it re-sourced common/rc ?
>> Yes, it should. init_rc() is getting called twice when common/rc is getting
>> re-sourced. Maybe I can do like
>>
>>
>> if $RECREATE_TEST_DEV || [ "$OLD_FSTYP" != "$FSTYP" ]; then
>>
>>      <...>
>>
>>      . common/rc # changes in this patch
>>
>>      <...>
>>
>> elif [ "$OLD_TEST_FS_MOUNT_OPTS" != "$TEST_FS_MOUNT_OPTS" ]; then
>>
>>      ...
>>
>>      init_rc() # explicitly adding an init_rc() for this condition
>>
>> else
>>
>>      init_rc() # # explicitly adding an init_rc() for all other conditions.
>> This will prevent init_rc() from getting called twice during re-sourcing
>> common/rc
>>
>> fi
>>
>> What do you think?
> Sounds fine as a mechanical change, but I wonder, should calling init_rc
> be explicit?  There are not so many places that source common/rc:
>
> $ git grep 'common/rc'
> check:362:if ! . ./common/rc; then
> check:836:              . common/rc
> common/preamble:52:     . ./common/rc
> soak:7:. ./common/rc
> tests/generic/749:18:. ./common/rc
>
> (I filtered out the non-executable matches)
>
> I think the call in generic/749 is unnecessary and I don't know what
> soak does.  But that means that one could insert an explicit call to
> init_rc at line 366 and 837 in check and at line 53 in common/preamble,
> and we can clean up one more of those places where sourcing a common/
> file actually /does/ something quietly under the covers.

Okay just to clear my understanding, do you mean that the call to 
init_rc() be removed from common/rc file and the places which actually 
need the call to init_rc, explicitly calls init_rc() instead of sourcing 
". common/rc" and making common/rc do something under the cover?

--NR

>
> (Unless the maintainer is ok with the status quo...?)
>
> --D
>
>>> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
>>>
>>> --D
>>>
>>>> ...
>>>>
>>>> --NR
>>>>
>>>>
>>>>
>>>>>> -		then
>>>>>> -			echo "check: failed to mount $TEST_DEV on $TEST_DIR"
>>>>>> -			status=1
>>>>>> -			exit
>>>>>> -		fi
>>>>>> -		# TEST_DEV has been recreated, previous FSTYP derived from
>>>>>> -		# TEST_DEV could be changed, source common/rc again with
>>>>>> -		# correct FSTYP to get FSTYP specific configs, e.g. common/xfs
>>>>>> +		# Previous FSTYP derived from TEST_DEV could be changed, source
>>>>>> +		# common/rc again with correct FSTYP to get FSTYP specific configs,
>>>>>> +		# e.g. common/xfs
>>>>>>     		. common/rc
>>>>>>     		_prepare_test_list
>>>>>>     	elif [ "$OLD_TEST_FS_MOUNT_OPTS" != "$TEST_FS_MOUNT_OPTS" ]; then
>>>>>> -- 
>>>>>> 2.34.1
>>>>>>
>>>>>>
>>>> -- 
>>>> Nirjhar Roy
>>>> Linux Kernel Developer
>>>> IBM, Bangalore
>>>>
>> -- 
>> Nirjhar Roy
>> Linux Kernel Developer
>> IBM, Bangalore
>>
>>
-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore