[PATCH v3 2/2] selftests/mm: load xfs before checking for it in run_vmtests.sh

[Qiliang Yuan <odys.yuan@gmail.com>]

run_vmtests.sh creates a loop-mounted XFS for "khugepaged all:file" and
for the pagecache folio split cases of split_huge_page_test, since
tmpfs does not give them large pagecache folios.

It only does so when xfs already shows up in /proc/filesystems. When
xfs is built as a module that is not loaded yet, the check fails, no
XFS is created, "khugepaged all:file" is reported as skipped and every
pagecache folio split case of split_huge_page_test is skipped with "No
large pagecache folio generated".

Load xfs with load_module() when it is not registered yet, so that it
is unloaded again once the script is done. Match xfs as a whole word,
as "selinuxfs" contains it too, as does "vxfs" on kernels before 7.3,
and would otherwise skip the load and leave xfs to be loaded by
mount(). "run_vmtests.sh -t thp" with xfs built as a module and not
loaded:

                                        before    after
  khugepaged all:file                  skipped      run
  skipped split_huge_page_test cases        43        0
  xfs loaded after the run                  no       no
  xfs loaded after the run, with
  selinuxfs or vxfs registered             yes       no

Fixes: fc4d182316bd ("mm: huge_memory: enable debugfs to split huge pages to any order")
Signed-off-by: Qiliang Yuan <odys.yuan@gmail.com>
---
 tools/testing/selftests/mm/run_vmtests.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index e104a9c6fdefb..b422edc2e2664 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -412,7 +412,7 @@ CATEGORY="thp" run_test ./khugepaged -s 4 all:shmem
 # Try to create XFS if not provided
 if [ -z "${SPLIT_HUGE_PAGE_TEST_XFS_PATH}" ]; then
     if test_selected "thp"; then
-	if grep xfs /proc/filesystems &>/dev/null; then
+	if grep -qw xfs /proc/filesystems || load_module xfs; then
 	    XFS_IMG=$(mktemp /tmp/xfs_img_XXXXXX)
 	    XFS_DIR=$(mktemp -d /tmp/xfs_dir_XXXXXX)
 	    truncate -s 314572800 ${XFS_IMG}

-- 
2.43.0