Extend unit test for is_local_fs from fsdev.h

The test uses a fake `mtab` file which contains 1 entry for a local
filesystem, 1 entry for a direct autofs map and 1 entry for a NFS
system mounted using autofs. By parsing the `mtab` file only 1 local
filesystem should be found. It will help us to test
#1329

Author: jan-cerny

tests/API/probes/Makefile.am

@@ -1,4 +1,5 @@
 AM_CPPFLAGS = \
+	-DDATADIR=\"$(srcdir)/\" \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/CCE/public \
 	-I$(top_srcdir)/src/CPE/public \
@@ -35,6 +36,7 @@ test_fsdev_is_local_fs_SOURCES = test_fsdev_is_local_fs.c
 
 EXTRA_DIST += \
 	all.sh \
+	fake_mtab \
 	fts.sh \
 	gentree.sh \
 	test_api_probes_smoke.c \

tests/API/probes/fake_mtab

@@ -0,0 +1,3 @@
+/dev/mapper/fedora-root / ext4 rw,seclabel,relatime 0 0
+/etc/mount.map /nfs/test autofs rw,relatime,fd=17,pgrp=11111,timeout=5,minproto=5,maxproto=5,direct,pipe_ino=1246883 0 0
+192.168.122.231:/test /nfs/test nfs4 rw,relatime,vers=4.2,rsize=262144,wsize=262144,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=192.168.122.1,local_lock=none,addr=192.168.122.231 0 0

tests/API/probes/test_fsdev_is_local_fs.c

@@ -29,13 +29,43 @@
 #include <mntent.h>
 #include "fsdev.h"
 
-int main(int argc, char *argv[])
+static int test_single_call()
 {
 	struct mntent ment;
 	ment.mnt_type = "autofs";
 	int ret = is_local_fs(&ment);
-	if (ret != 0) {
+	/* autofs entry is never considered local */
+	return (ret == 0);
+}
+
+static int test_multiple_calls()
+{
+	/* fake mtab contains only 1 local filesystem */
+	FILE *f = setmntent(DATADIR "fake_mtab", "r");
+	if (f == NULL) {
+		fprintf(stderr, "fake_mtab could not be open\n");
+		return 0;
+	}
+	struct mntent *ment;
+	unsigned int locals = 0;
+	while ((ment = getmntent(f)) != NULL) {
+		if (is_local_fs(ment)) {
+			locals++;
+		}
+	}
+	endmntent(f);
+	return (locals == 1);
+}
+
+int main(int argc, char *argv[])
+{
+	if (!test_single_call()) {
+		fprintf(stderr, "test_single_call has failed\n");
+		return 1;
+	}
+	if (!test_multiple_calls()) {
+		fprintf(stderr, "test_multiple_calls has failed\n");
 		return 1;
 	}
 	return 0;
-}
+}