udev/node: drop support of old file format in /run/udev/links/

The new file format in /run/udev/links/ has been introduced in
377a83f0d80376456d9be203796f66f543a8b943 (v250, released on 2021-12-23).
Let's drop the old format support, to simplify the logic.

diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c
index d30ffd9a56e4238341f58e421d4615dda8110786..4d1ecf5d116a1d6f5cd8a8d8cb46f362561765be 100644 (file)
--- a/src/udev/udev-node.c
+++ b/src/udev/udev-node.c
@@ -79,84 +79,48 @@ static int node_create_symlink(sd_device *dev, const char *devnode, const char *
 }
 
 static int stack_directory_read_one(int dirfd, const char *id, char **devnode, int *priority) {
-        _cleanup_free_ char *buf = NULL;
-        int tmp_prio, r;
+        int r;
 
         assert(dirfd >= 0);
         assert(id);
         assert(priority);
 
-        /* This reads priority and device node from the symlink under /run/udev/links (or udev database).
+        /* This reads priority and device node from the symlink under /run/udev/links/ directory.
          * If 'devnode' is NULL, obtained priority is always set to '*priority'. If 'devnode' is non-NULL,
-         * this updates '*devnode' and '*priority'. */
+         * this updates '*devnode' and '*priority' if the obtained one has a higher priority. */
 
-        /* First, let's try to read the entry with the new format, which should replace the old format pretty
-         * quickly. */
+        _cleanup_free_ char *buf = NULL;
         r = readlinkat_malloc(dirfd, id, &buf);
-        if (r >= 0) {
-                char *colon;
-
-                /* With the new format, the devnode and priority can be obtained from symlink itself. */
-
-                colon = strchr(buf, ':');
-                if (!colon || colon == buf)
-                        return -EINVAL;
+        if (r < 0)
+                return r == -ENOENT ? -ENODEV : r;
 
-                *colon = '\0';
+        char *colon = strchr(buf, ':');
+        if (!colon || colon == buf)
+                return -EINVAL;
 
-                /* Of course, this check is racy, but it is not necessary to be perfect. Even if the device
-                 * node will be removed after this check, we will receive 'remove' uevent, and the invalid
-                 * symlink will be removed during processing the event. The check is just for shortening the
-                 * timespan that the symlink points to a non-existing device node. */
-                if (access(colon + 1, F_OK) < 0)
-                        return -ENODEV;
+        *colon = '\0';
 
-                r = safe_atoi(buf, &tmp_prio);
-                if (r < 0)
-                        return r;
+        /* Of course, this check is racy, but it is not necessary to be perfect. Even if the device
+         * node will be removed after this check, we will receive 'remove' uevent, and the invalid
+         * symlink will be removed during processing the event. The check is just for shortening the
+         * timespan that the symlink points to a non-existing device node. */
+        if (access(colon + 1, F_OK) < 0)
+                return -ENODEV;
 
-                if (!devnode)
-                        goto finalize;
+        int tmp_prio;
+        r = safe_atoi(buf, &tmp_prio);
+        if (r < 0)
+                return r;
 
+        if (devnode) {
                 if (*devnode && tmp_prio <= *priority)
                         return 0; /* Unchanged */
 
                 r = free_and_strdup(devnode, colon + 1);
                 if (r < 0)
                         return r;
+        }
 
-        } else if (r == -EINVAL) { /* Not a symlink ? try the old format */
-                _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
-                const char *val;
-
-                /* Old format. The devnode and priority must be obtained from uevent and udev database. */
-
-                r = sd_device_new_from_device_id(&dev, id);
-                if (r < 0)
-                        return r;
-
-                r = device_get_devlink_priority(dev, &tmp_prio);
-                if (r < 0)
-                        return r;
-
-                if (!devnode)
-                        goto finalize;
-
-                if (*devnode && tmp_prio <= *priority)
-                        return 0; /* Unchanged */
-
-                r = sd_device_get_devname(dev, &val);
-                if (r < 0)
-                        return r;
-
-                r = free_and_strdup(devnode, val);
-                if (r < 0)
-                        return r;
-
-        } else
-                return r == -ENOENT ? -ENODEV : r;
-
-finalize:
         *priority = tmp_prio;
         return 1; /* Updated */
 }