[LTP] [RFC PATCH 1/1] tst_test.sh: Fix filesystem support detection

[Petr Vorel]

Filesystem detection of locally used filesystem was broken on tests
which did not use TST_ALL_FILESYSTEMS as it 1) expected used filesystem
is $TST_FS_TYPE 2) this variable was not yet set.

Also this check makes sense only if test defines TST_SKIP_FILESYSTEMS
(to align with the condition in do_test_setup() in C API).

Move filesystem check after (optional) cd "$TST_TMPDIR" (TMPDIR can have
different filesystem).

Not printing extra TINFO "$_tst_fs is supported by the test" (which is
printed in C API) when test is supported, because there is already
similar TINFO from testcases/lib/tst_supported_fs.c:
tst_supported_fs.c:104: TINFO: btrfs is not skipped

Fixes: 1f6bd6e66 ("tst_test.sh: Add $TST_ALL_FILESYSTEMS")

Reported-by: Martin Doucha <mdoucha@suse.cz>
Signed-off-by: Petr Vorel <pvorel@suse.cz>
---
First, sorry for introducing a regression.

I don't like df and tail dependency. Also df output is stable (even on
busybox), but I'd prefer to use code from do_test_setup() in lib/tst_test.c:

	long fs_type = tst_fs_type(".");
	const char *fs_name = tst_fs_type_name(fs_type);

Instead adding yet another binary, I wonder if we could add extra getopt
parameter to ask for current filesystem.

i.e. to replace:
-tst_supported_fs -s skip_list fs_type
+tst_supported_fs -s skip_list -d DIR

Because 'tst_supported_fs -s skip_list fs_type' mode is used only in
tst_test.sh.

Whole help would be:

$ ./testcases/lib/tst_supported_fs -h
* all filesystems
tst_supported_fs [-s skip_list]
   print the list of supported filesystems
   if fs_type is supported and not in skip_list (optional),
   print list of supported filesystems and return 0
   if fs_type isn't supported or in skip_list, return 1

* single filesystem
tst_supported_fs fs_type
   if fs_type is supported, return 0 otherwise return 1

-tst_supported_fs -s skip_list fs_type
+tst_supported_fs -s skip_list -d DIR
   if fs_type is in skip_list, return 1 otherwise return 0

fs_type - a specified filesystem type
skip_list - filesystems to skip, delimiter: ','

 testcases/lib/tst_test.sh | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/testcases/lib/tst_test.sh b/testcases/lib/tst_test.sh
index 229317713..1691846ae 100644
--- a/testcases/lib/tst_test.sh
+++ b/testcases/lib/tst_test.sh
@@ -703,12 +703,6 @@ tst_run()
 	[ "$TST_FORMAT_DEVICE" = 1 -o "$TST_ALL_FILESYSTEMS" = 1 ] && TST_NEEDS_DEVICE=1
 	[ "$TST_NEEDS_DEVICE" = 1 ] && TST_NEEDS_TMPDIR=1
 
-	if [ "$TST_ALL_FILESYSTEMS" != 1 ]; then
-		if ! tst_supported_fs -s "$TST_SKIP_FILESYSTEMS" $TST_FS_TYPE > /dev/null; then
-			tst_brk TCONF "$TST_FS_TYPE is skipped by the test"
-		fi
-	fi
-
 	if [ "$TST_NEEDS_DEVICE" = 1 ]; then
 		TST_DEVICE=$(tst_device acquire)
 
@@ -736,6 +730,15 @@ tst_run()
 		cd "$TST_TMPDIR"
 	fi
 
+	if [ "$TST_ALL_FILESYSTEMS" != 1 -a "$TST_SKIP_FILESYSTEMS" ]; then
+		tst_require_cmds df tail
+		_tst_fs="$(df -T . | tail -1 | awk '{print $2}')"
+		[ "$_tst_fs" ] || tst_brk TBROK "failed to detect filesystem for $PWD"
+		if ! tst_supported_fs -s "$TST_SKIP_FILESYSTEMS" $_tst_fs > /dev/null; then
+			tst_brk TCONF "$_tst_fs is not supported by the test"
+		fi
+	fi
+
 	[ -n "$TST_NEEDS_CHECKPOINTS" ] && _tst_init_checkpoints
 
 	TST_MNTPOINT="${TST_MNTPOINT:-$PWD/mntpoint}"
-- 
2.37.3