Message-ID: <61e3d66b-7cb0-4392-af96-10c2b011738f@gmail.com>
Date: Wed, 12 Mar 2025 11:16:06 +0530
From: "Nirjhar Roy (IBM)" <nirjhar.roy.lists@...il.com>
To: "Darrick J. Wong" <djwong@...nel.org>
Cc: fstests@...r.kernel.org, linux-ext4@...r.kernel.org,
 linux-xfs@...r.kernel.org, ritesh.list@...il.com, ojaswin@...ux.ibm.com,
 zlang@...nel.org, david@...morbit.com
Subject: Re: [PATCH v1 2/2] check,common/{preamble,rc},soak: Decoupling
 init_rc() call from sourcing common/rc


On 3/7/25 23:10, Darrick J. Wong wrote:
> On Fri, Mar 07, 2025 at 11:21:15AM +0530, Nirjhar Roy (IBM) wrote:
>> On 3/6/25 23:16, Darrick J. Wong wrote:
>>> On Thu, Mar 06, 2025 at 08:17:41AM +0000, Nirjhar Roy (IBM) wrote:
>>>> Silently executing scripts during sourcing common/rc doesn't look good
>>>> and also causes unnecessary script execution. Decouple init_rc() call
>>>> and call init_rc() explicitly where required.
>>>>
>>>> Signed-off-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@...il.com>
>>>> ---
>>>>    check           | 10 ++--------
>>>>    common/preamble |  1 +
>>>>    common/rc       |  2 --
>>>>    soak            |  1 +
>>>>    4 files changed, 4 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/check b/check
>>>> index ea92b0d6..d30af1ba 100755
>>>> --- a/check
>>>> +++ b/check
>>>> @@ -840,16 +840,8 @@ function run_section()
>>>>    		_prepare_test_list
>>>>    	elif [ "$OLD_TEST_FS_MOUNT_OPTS" != "$TEST_FS_MOUNT_OPTS" ]; then
>>>>    		_test_unmount 2> /dev/null
>>>> -		if ! _test_mount
>>>> -		then
>>>> -			echo "check: failed to mount $TEST_DEV on $TEST_DIR"
>>>> -			status=1
>>>> -			exit
>>>> -		fi
>>> Unrelated change?  I was expecting a mechanical ". ./common/rc" =>
>>> ". ./common/rc ; init_rc" change in this patch.
>> This patch adds an init_rc() call to _begin_fstests() in common/preamble and
>> hence the above _test_mount() will be executed during that call. So this
>> _test_mount isn't necessary here, right? _test_mount() will be executed (as
>> a part of init_rc() call) before every test run. Please let me know if my
>> understanding isn't correct.
> It's true that in terms of getting the test filesystem mounted, the
> _test_mount here and in init_rc are redundant.  But look at what happens
> on error here -- we print "check: failed to mount..." to signal that the
> new section's TEST_FS_MOUNT_OPTS are not valid, and exit the ./check
> process.
>
> By deferring the mount to the init_rc in _preamble, that means that
> we'll run the whole section with bad mount options, most likely
> resulting in every test spewing "common/rc: could not mount..." and
> appearing to fail.
Aah, right. The exit should be at the check level if some parameter is 
not correct in a section. I will make the change in v2.
>
> I think.  I'm not sure what "status=1; exit" does as compared to
> "exit 1"; AFAICT the former actually results in an exit code of 0
> because the (otherwise pointless) assignment succeeds.

I think "status=0; exit" has a reason. If we see the following trap 
handler registration in the check script:

if $OPTIONS_HAVE_SECTIONS; then
     trap "_kill_seq; _summary; exit \$status" 0 1 2 3 15
else
     trap "_kill_seq; _wrapup; exit \$status" 0 1 2 3 15
fi

So, "exit 1" will exit the check script without setting the correct 
return value. I ran with the following local.config file:

[xfs_4k_valid]
FSTYP=xfs
TEST_DEV=/dev/loop0
TEST_DIR=/mnt1/test
SCRATCH_DEV=/dev/loop1
SCRATCH_MNT=/mnt1/scratch

[xfs_4k_invalid]
FSTYP=xfs
TEST_DEV=/dev/loop0
TEST_DIR=/mnt1/invalid_dir
SCRATCH_DEV=/dev/loop1
SCRATCH_MNT=/mnt1/scratch

This caused the init_rc() to catch the case of invalid _test_mount 
options. Although the check script correctly failed during the execution 
of the "xfs_4k_invalid" section, the return value was 0, i.e "echo $?" 
returned 0. This is because init_rc exits with "exit 1" without 
correctly setting the value of "status".

However, when I executed with the following local.config file:

[xfs_4k_valid]
FSTYP=xfs
TEST_DEV=/dev/loop0
TEST_DIR=/mnt1/test
SCRATCH_DEV=/dev/loop1
SCRATCH_MNT=/mnt1/scratch

[xfs_4k_invalid]
FSTYP=xfs
TEST_DEV=/dev/loop0
TEST_DIR=/mnt1/invalid_dir
SCRATCH_DEV=/dev/loop1
SCRATCH_MNT=/mnt1/scratch
TEST_FS_MOUNT_OPTS="-o invalidss"

This caused the "elif [ "$OLD_TEST_FS_MOUNT_OPTS" != 
"$TEST_FS_MOUNT_OPTS" ]; then" to be executed. Now, when I checked the 
value of "echo $?", it showed 1. IMO, this is the correct behavior, and 
we should always use "status=<value>; exit" and NOT "exit 1" directly. 
Even if 1 section fails,   "./check <test-list>" command should return a 
non-zero value. Can you please let me know if my understanding is 
correct? If yes, maybe we can have a function like

_set_status_and_exit()
{

     status="$1"
     exit
}

and replace all the "status <value>; exit" and "exit <value>" with 
"_set_status_and_exit <value>"

--NR


>
> Granted, the init_rc that you remove below would also catch that case
> and exit ./check
Yes. init_rc can catch that case with an additional difference that it 
will attempt another mount "retrying test device mount with external set"
>
>>>>    	fi
>>>> -	init_rc
>>> Why remove init_rc here?
>> Same reason as above.
> But that's an additional change in behavior.  If there's no reason for
> calling init_rc() from run_section() then that should be a separate
> patch with a separate justification.

Since the check for _test_mount should be at the check script level and 
not at the _begin_fstest(), maybe we should

1. Keep the init_rc call here

2. Remove the _test_mount above (the one with "elif [ 
"$OLD_TEST_FS_MOUNT_OPTS" != "$TEST_FS_MOUNT_OPTS" ]; then" ) and have a 
separate patch for it with proper justification.

3. NOT have any init_rc call in _begin_fstest(), since the _test_mount 
related checks would already been done by the time _begin_fstests() gets 
executed.

The above changes will also not change any existing behavior. Can you 
please let me know your thoughts and I can send a V2 accordingly?

--NR

>
> --D
>
>>>> -
>>>>    	seq="check.$$"
>>>>    	check="$RESULT_BASE/check"
>>>> @@ -870,6 +862,8 @@ function run_section()
>>>>    	needwrap=true
>>>>    	if [ ! -z "$SCRATCH_DEV" ]; then
>>>> +		_check_mounted_on SCRATCH_DEV $SCRATCH_DEV SCRATCH_MNT $SCRATCH_MNT
>>>> +		[ $? -le 1 ] || exit 1
>>>>    	  _scratch_unmount 2> /dev/null
>>>>    	  # call the overridden mkfs - make sure the FS is built
>>>>    	  # the same as we'll create it later.
>>>> diff --git a/common/preamble b/common/preamble
>>>> index 0c9ee2e0..c92e55bb 100644
>>>> --- a/common/preamble
>>>> +++ b/common/preamble
>>>> @@ -50,6 +50,7 @@ _begin_fstest()
>>>>    	_register_cleanup _cleanup
>>>>    	. ./common/rc
>>>> +	init_rc
>>>>    	# remove previous $seqres.full before test
>>>>    	rm -f $seqres.full $seqres.hints
>>>> diff --git a/common/rc b/common/rc
>>>> index d2de8588..f153ad81 100644
>>>> --- a/common/rc
>>>> +++ b/common/rc
>>>> @@ -5754,8 +5754,6 @@ _require_program() {
>>>>    	_have_program "$1" || _notrun "$tag required"
>>>>    }
>>>> -init_rc
>>>> -
>>>>    ################################################################################
>>>>    # make sure this script returns success
>>>>    /bin/true
>>>> diff --git a/soak b/soak
>>>> index d5c4229a..5734d854 100755
>>>> --- a/soak
>>>> +++ b/soak
>>>> @@ -5,6 +5,7 @@
>>>>    # get standard environment, filters and checks
>>>>    . ./common/rc
>>>> +# ToDo: Do we need an init_rc() here? How is soak used?
>>> I have no idea what soak does and have never used it, but I think for
>>> continuity's sake you should call init_rc here.
>> Okay. I think Dave has suggested removing this file[1]. This doesn't seem to
>> used anymore.
>>
>> [1] https://lore.kernel.org/all/Z8oT_tBYG-a79CjA@dread.disaster.area/
>>
>> --NR
>>
>>> --D
>>>
>>>>    . ./common/filter
>>>>    tmp=/tmp/$$
>>>> -- 
>>>> 2.34.1
>>>>
>>>>
>> -- 
>> Nirjhar Roy
>> Linux Kernel Developer
>> IBM, Bangalore
>>
>>
-- 
Nirjhar Roy
Linux Kernel Developer
IBM, Bangalore

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