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

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

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.

(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
> 
>