umount: simplify code for deactivating loop devices

[elogind.git] / src / umount.c

diff --git a/src/umount.c b/src/umount.c
index 4842d403aeac8eea11b363c75eb185144f1d9c2c..ff1296fc0f7a77cb125a58fd9bd4805d62850916 100644 (file)
--- a/src/umount.c
+++ b/src/umount.c
@@ -35,10 +35,10 @@
 
 typedef struct MountPoint {
         char *path;
-        bool read_only;
         LIST_FIELDS (struct MountPoint, mount_point);
 } MountPoint;
 
+/* Takes over possession of path */
 static MountPoint *mount_point_alloc(char *path) {
         MountPoint *mp;
 
@@ -46,8 +46,6 @@ static MountPoint *mount_point_alloc(char *path) {
                 return NULL;
 
         mp->path = path;
-        mp->read_only = false;
-
         return mp;
 }
 
@@ -101,23 +99,26 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
                         continue;
                 }
 
-                if (mount_point_is_api(path)) {
-                        free(path);
-                        continue;
-                }
+                p = cunescape(path);
+                free(path);
 
-                if (!(p = cunescape(path))) {
+                if (!p) {
                         r = -ENOMEM;
                         goto finish;
                 }
 
+                if (mount_point_is_api(p)) {
+                        free(p);
+                        continue;
+                }
+
                 if (!(mp = mount_point_alloc(p))) {
+                        free(p);
                         r = -ENOMEM;
                         goto finish;
                 }
-                LIST_PREPEND(MountPoint, mount_point, *mount_point_list_head, mp);
 
-                free(path);
+                LIST_PREPEND(MountPoint, mount_point, *mount_point_list_head, mp);
         }
 
         r = 0;
@@ -125,8 +126,6 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
 finish:
         fclose(proc_self_mountinfo);
 
-        free(path);
-
         return r;
 }
 
@@ -228,16 +227,27 @@ static int loopback_list_get(MountPoint **loopback_list_head) {
 
         udev_list_entry_foreach(item, first) {
                 MountPoint *lb;
+                struct udev_device *d;
                 char *loop;
+                const char *dn;
 
-                loop = cunescape(udev_list_entry_get_name(item));
-                if (!loop) {
+                if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
                         r = -ENOMEM;
                         goto finish;
                 }
 
-                lb = mount_point_alloc(loop);
-                if (!lb) {
+                if ((dn = udev_device_get_devnode(d))) {
+                        loop = strdup(dn);
+                        udev_device_unref(d);
+
+                        if (!loop) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+                } else
+                        udev_device_unref(d);
+
+                if (!(lb = mount_point_alloc(loop))) {
                         free(loop);
                         r = -ENOMEM;
                         goto finish;
@@ -252,30 +262,23 @@ finish:
         if (e)
                 udev_enumerate_unref(e);
 
-        free(udev);
+        if (udev)
+                udev_unref(udev);
+
         return r;
 }
 
 static int delete_loopback(const char *device) {
         int fd, r;
 
-        if ((fd = open(device, O_RDONLY|O_CLOEXEC)) < 0) {
-                if (errno == ENOENT) {
-                        log_debug("Loop device %s does not exist.", device);
-                        errno = 0;
-                        return 0;
-                }
+        if ((fd = open(device, O_RDONLY|O_CLOEXEC)) < 0)
                 return -errno;
-        }
 
-        ioctl(fd, LOOP_CLR_FD, 0);
-        r = errno;
-        close_nointr(fd);
+        r = ioctl(fd, LOOP_CLR_FD, 0);
+        close_nointr_nofail(fd);
 
-        if (r == ENXIO) /* not bound, so no error */
-                r = 0;
-        errno = r;
-        return -errno;
+        /* ENXIO: not bound, so no error */
+        return (r >= 0 || errno == ENXIO) ? 0 : -errno;
 }
 
 static int mount_points_list_umount(MountPoint **mount_point_list_head) {
@@ -303,14 +306,10 @@ static int mount_points_list_remount_read_only(MountPoint **mount_point_list_hea
         int failed = 0;
 
         LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) {
-                if (mp->read_only)
-                        continue;
-
                 /* Trying to remount read-only */
-                if (mount(NULL, mp->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0) {
-                        mp->read_only = true;
+                if (mount(NULL, mp->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0)
                         mount_point_remove_and_free(mp, mount_point_list_head);
-                } else {
+                else {
                         log_debug("Could not remount as read-only %s: %m", mp->path);
                         failed++;
                 }