tests: add a simple test for the mountinfo parsing logic

src/core/umount.c

@@ -37,7 +37,6 @@
 #include "fd-util.h"
 #include "fstab-util.h"
 #include "linux-3.13/dm-ioctl.h"
-#include "list.h"
 #include "mount-setup.h"
 #include "mount-util.h"
 #include "path-util.h"
@@ -52,15 +51,6 @@
 DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_table*, mnt_free_table);
 DEFINE_TRIVIAL_CLEANUP_FUNC(struct libmnt_iter*, mnt_free_iter);
 
-typedef struct MountPoint {
-        char *path;
-        char *remount_options;
-        unsigned long remount_flags;
-        bool try_remount_ro;
-        dev_t devnum;
-        LIST_FIELDS(struct MountPoint, mount_point);
-} MountPoint;
-
 static void mount_point_free(MountPoint **head, MountPoint *m) {
         assert(head);
         assert(m);
@@ -72,14 +62,14 @@ static void mount_point_free(MountPoint **head, MountPoint *m) {
         free(m);
 }
 
-static void mount_points_list_free(MountPoint **head) {
+void mount_points_list_free(MountPoint **head) {
         assert(head);
 
         while (*head)
                 mount_point_free(head, *head);
 }
 
-static int mount_points_list_get(MountPoint **head) {
+int mount_points_list_get(const char *mountinfo, MountPoint **head) {
         _cleanup_(mnt_free_tablep) struct libmnt_table *t = NULL;
         _cleanup_(mnt_free_iterp) struct libmnt_iter *i = NULL;
         int r;
@@ -91,9 +81,9 @@ static int mount_points_list_get(MountPoint **head) {
         if (!t || !i)
                 return log_oom();
 
-        r = mnt_table_parse_mtab(t, NULL);
+        r = mnt_table_parse_mtab(t, mountinfo);
         if (r < 0)
-                return log_error_errno(r, "Failed to parse /proc/self/mountinfo: %m");
+                return log_error_errno(r, "Failed to parse %s: %m", mountinfo);
 
         for (;;) {
                 struct libmnt_fs *fs;
@@ -108,7 +98,7 @@ static int mount_points_list_get(MountPoint **head) {
                 if (r == 1)
                         break;
                 if (r < 0)
-                        return log_error_errno(r, "Failed to get next entry from /proc/self/mountinfo: %m");
+                        return log_error_errno(r, "Failed to get next entry from %s: %m", mountinfo);
 
                 path = mnt_fs_get_target(fs);
                 if (!path)
@@ -661,7 +651,7 @@ static int umount_all_once(bool *changed, int umount_log_level) {
         assert(changed);
 
         LIST_HEAD_INIT(mp_list_head);
-        r = mount_points_list_get(&mp_list_head);
+        r = mount_points_list_get(NULL, &mp_list_head);
         if (r < 0)
                 goto end;
 

src/core/umount.h

@@ -20,6 +20,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include "list.h"
+
 int umount_all(bool *changed, int umount_log_level);
 
 int swapoff_all(bool *changed);
@@ -27,3 +29,16 @@ int swapoff_all(bool *changed);
 int loopback_detach_all(bool *changed, int umount_log_level);
 
 int dm_detach_all(bool *changed, int umount_log_level);
+
+/* This is exported just for testing */
+typedef struct MountPoint {
+        char *path;
+        char *remount_options;
+        unsigned long remount_flags;
+        bool try_remount_ro;
+        dev_t devnum;
+        LIST_FIELDS(struct MountPoint, mount_point);
+} MountPoint;
+
+int mount_points_list_get(const char *mountinfo, MountPoint **head);
+void mount_points_list_free(MountPoint **head);

src/test/meson.build

@@ -652,6 +652,14 @@ tests += [
          [],
          [libdl],
          '', 'manual'],
+
+        [['src/test/test-umount.c',
+          'src/core/mount-setup.c',
+          'src/core/mount-setup.h',
+          'src/core/umount.c',
+          'src/core/umount.h'],
+         [],
+         [libmount]],
 ]
 
 ############################################################

src/test/test-umount.c

@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "log.h"
+#include "string-util.h"
+#include "tests.h"
+#include "umount.h"
+#include "util.h"
+
+static void test_mount_points_list(const char *fname) {
+        LIST_HEAD(MountPoint, mp_list_head);
+        MountPoint *m;
+
+        log_info("/* %s(\"%s\") */", __func__, fname ?: "/proc/self/mountinfo");
+
+        LIST_HEAD_INIT(mp_list_head);
+        assert_se(mount_points_list_get(fname, &mp_list_head) >= 0);
+
+        LIST_FOREACH(mount_point, m, mp_list_head)
+                log_debug("path=%s o=%s f=0x%lx try-ro=%s dev=%u:%u",
+                          m->path,
+                          strempty(m->remount_options),
+                          m->remount_flags,
+                          yes_no(m->try_remount_ro),
+                          major(m->devnum), minor(m->devnum));
+
+        mount_points_list_free(&mp_list_head);
+}
+
+int main(int argc, char **argv) {
+        log_set_max_level(LOG_DEBUG);
+        log_parse_environment();
+        log_open();
+
+        test_mount_points_list(NULL);
+        test_mount_points_list(get_testdata_dir("/test-umount/empty.mountinfo"));
+        test_mount_points_list(get_testdata_dir("/test-umount/garbled.mountinfo"));
+        test_mount_points_list(get_testdata_dir("/test-umount/rhbug-1554943.mountinfo"));
+}