Re: [PATCH 1/2] fstests: move fs-module reload to earlier in the run_section function

["Darrick J. Wong" <djwong@kernel.org>]

On Fri, Nov 15, 2024 at 11:20:51PM +0800, Anand Jain wrote:
> Reload the module before each test, instead of later in run_section.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  check | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/check b/check
> index 9222cd7e4f81..d8ee73f48c77 100755
> --- a/check
> +++ b/check
> @@ -935,6 +935,15 @@ function run_section()
>  			continue
>  		fi
>  
> +		# Reload the module after each test to check for leaks or
> +		# other problems.

Hrmm.  The nice thing about doing the reload /after/ each test is that
unloading the module will purge any per-fs slab caches that the module
creates.  The slab teardown logs any forgotten objects while $seq still
points to the test that leaked those objects.  Granted it's not a 100%
solution (that job falls to kmemcheck) but it's a cheap check.

This change makes it so that if test N leaks something, fstests reports
them for test N+1.

--D

> +		if [ -n "${TEST_FS_MODULE_RELOAD}" ]; then
> +			_test_unmount 2> /dev/null
> +			_scratch_unmount 2> /dev/null
> +			modprobe -r fs-$FSTYP
> +			modprobe fs-$FSTYP
> +		fi
> +
>  		# record that we really tried to run this test.
>  		if ((!${#loop_status[*]})); then
>  			try+=("$seqnum")
> @@ -1033,15 +1042,6 @@ function run_section()
>  			done
>  		fi
>  
> -		# Reload the module after each test to check for leaks or
> -		# other problems.
> -		if [ -n "${TEST_FS_MODULE_RELOAD}" ]; then
> -			_test_unmount 2> /dev/null
> -			_scratch_unmount 2> /dev/null
> -			modprobe -r fs-$FSTYP
> -			modprobe fs-$FSTYP
> -		fi
> -
>  		# Scan for memory leaks after every test so that associating
>  		# a leak to a particular test will be as accurate as possible.
>  		_check_kmemleak || tc_status="fail"
> -- 
> 2.46.1
> 
>