lib: Factor out is_supported() && Add tst_supported_fs

1) Factor out is_supported() and rename it as tst_fs_is_supported(),
   so that some tests can check a specified filesystem by it.

2) Add tst_supported_fs binary for shell tests to check a specified
   filesystem or all supported fielsystems.

   PS: hint messages from tst_supported_fs binary is targeted as stderr,
       so we can filter them by "2> /dev/null".

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>

2 files changed, 48 insertions, 1 deletions

diff --git a/testcases/lib/Makefile b/testcases/lib/Makefile
index 77b7b2ef1..3547e16dc 100644
--- a/testcases/lib/Makefile
+++ b/testcases/lib/Makefile
@@ -28,6 +28,6 @@ INSTALL_TARGETS		:= *.sh
 
 MAKE_TARGETS		:= tst_sleep tst_random tst_checkpoint tst_rod tst_kvcmp\
 			   tst_device tst_net_iface_prefix tst_net_ip_prefix tst_net_vars\
-			   tst_getconf
+			   tst_getconf tst_supported_fs
 
 include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/lib/tst_supported_fs.c b/testcases/lib/tst_supported_fs.c
new file mode 100644
index 000000000..ebebcbb37
--- /dev/null
+++ b/testcases/lib/tst_supported_fs.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018 FUJITSU LIMITED. All rights reserved.
+ * Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#define TST_NO_DEFAULT_MAIN
+#include "tst_test.h"
+#include "tst_fs.h"
+
+static void usage(void)
+{
+	fprintf(stderr, "Usage: tst_supported_fs [fs_type]\n");
+	fprintf(stderr, "   If fs_type is supported, return 0\n");
+	fprintf(stderr, "   If fs_type isn't supported, return 1\n");
+	fprintf(stderr, "   If fs_type isn't specified, print the list of supported filesystems\n");
+	fprintf(stderr, "   fs_type - a specified filesystem type\n");
+}
+
+int main(int argc, char *argv[])
+{
+	const char *const *filesystems;
+	int i;
+
+	if (argc > 2) {
+		fprintf(stderr, "Can't specify multiple fs_type\n");
+		usage();
+		return 2;
+	}
+
+	if (argv[1] && !strcmp(argv[1], "-h")) {
+		usage();
+		return 0;
+	}
+
+	if (argv[1])
+		return !tst_fs_is_supported(argv[1]);
+
+	filesystems = tst_get_supported_fs_types();
+	for (i = 0; filesystems[i]; i++)
+		printf("%s\n", filesystems[i]);
+
+	return 0;
+}