chiark / gitweb /
check the udevdb before assigning a new %e
authorKay Sievers <kay.sievers@suse.de>
Mon, 29 Aug 2005 01:48:17 +0000 (03:48 +0200)
committerKay Sievers <kay.sievers@suse.de>
Mon, 29 Aug 2005 01:48:17 +0000 (03:48 +0200)
A second "add" event created a new enumeration with %e. Check the
udevdb first and if a matching name is already used.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
udev_rules.c

index 459c27b..7c73356 100644 (file)
@@ -267,16 +267,58 @@ static int import_parent_into_env(struct udevice *udev, struct sysfs_class_devic
        return rc;
 }
 
-/* finds the lowest positive N such that <name>N isn't present in the udevdb
- * if <name> doesn't exist, 0 is returned, N otherwise
- */
-static int find_free_number(const char *name, const char *devpath)
+static int match_name_and_get_number(const char *base, const char *devname)
+{
+       size_t baselen;
+       char *endptr;
+       int num;
+
+       baselen = strlen(base);
+       if (strncmp(base, devname, baselen) != 0)
+               return -1;
+       if (devname[baselen] == '\0')
+               return 0;
+       if (!isdigit(devname[baselen]))
+               return -1;
+       num = strtoul(&devname[baselen], &endptr, 10);
+       if (endptr[0] != '\0')
+               return -1;
+       return num;
+}
+
+/* finds the lowest positive device number such that <name>N isn't present in the udevdb
+ * if <name> doesn't exist, 0 is returned, N otherwise */
+static int find_free_number(const char *base, const char *devpath)
 {
        char db_devpath[PATH_SIZE];
        char filename[PATH_SIZE];
+       struct udevice udev_db;
        int num = 0;
 
-       strlcpy(filename, name, sizeof(filename));
+       /* check if the device already owns a matching name */
+       udev_init_device(&udev_db, NULL, NULL, NULL);
+       if (udev_db_get_device(&udev_db, devpath) == 0) {
+               struct name_entry *name_loop;
+               int devnum;
+
+               devnum = match_name_and_get_number(base, udev_db.name);
+               if (devnum >= 0) {
+                       num = devnum;
+                       dbg("device '%s', already has the node '%s' with num %u, use it", devpath, base, num);
+                       goto out;
+               }
+               list_for_each_entry(name_loop, &udev_db.symlink_list, node) {
+                       devnum = match_name_and_get_number(base, name_loop->name);
+                       if (devnum >= 0) {
+                               num = devnum;
+                               dbg("device '%s', already has a symlink '%s' with num %u, use it", devpath, base, num);
+                               goto out;
+                       }
+               }
+       }
+
+       /* just search the database again and again until a free name is found */
+       strlcpy(filename, base, sizeof(filename));
        while (1) {
                dbg("look for existing node '%s'", filename);
                if (udev_db_lookup_name(filename, db_devpath, sizeof(db_devpath)) != 0) {
@@ -290,10 +332,12 @@ static int find_free_number(const char *name, const char *devpath)
                        num = -1;
                        break;
                }
-               snprintf(filename, sizeof(filename), "%s%d", name, num);
+               snprintf(filename, sizeof(filename), "%s%d", base, num);
                filename[sizeof(filename)-1] = '\0';
        }
 
+out:
+       udev_cleanup_device(&udev_db);
        return num;
 }
 
@@ -345,12 +389,12 @@ static int wait_for_sysfs(struct udevice *udev, const char *file, int timeout)
 
        while (--loop) {
                if (stat(filename, &stats) == 0) {
-                       dbg("file appeared after %i loops", (timeout * WAIT_LOOP_PER_SECOND) - loop-1);
+                       info("file appeared after %i loops", (timeout * WAIT_LOOP_PER_SECOND) - loop-1);
                        return 0;
                }
                usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
        }
-       dbg("waiting for '%s' failed", filename);
+       info("waiting for '%s' failed", filename);
        return -1;
 }
 
@@ -669,6 +713,7 @@ static int match_key(const char *key_name, struct udev_rule *rule, struct key *k
        return -1;
 }
 
+/* match a single rule against a given device and possibly its parent devices */
 static int match_rule(struct udevice *udev, struct udev_rule *rule,
                      struct sysfs_class_device *class_dev, struct sysfs_device *sysfs_device)
 {