1 files changed, 95 insertions, 5 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index d3da66682667..964a99d48bc4 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -122,6 +122,94 @@ static struct device_attribute dev_mtd_num =
         __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
 
 /**
+ * ubi_volume_notify - send a volume change notification.
+ * @ubi: UBI device description object
+ * @vol: volume description object of the changed volume
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ *
+ * This is a helper function which notifies all subscribers about a volume
+ * change event (creation, removal, re-sizing, re-naming, updating). Returns
+ * zero in case of success and a negative error code in case of failure.
+ */
+int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
+{
+        struct ubi_notification nt;
+
+        ubi_do_get_device_info(ubi, &nt.di);
+        ubi_do_get_volume_info(ubi, vol, &nt.vi);
+        return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
+}
+
+/**
+ * ubi_notify_all - send a notification to all volumes.
+ * @ubi: UBI device description object
+ * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
+ * @nb: the notifier to call
+ *
+ * This function walks all volumes of UBI device @ubi and sends the @ntype
+ * notification for each volume. If @nb is %NULL, then all registered notifiers
+ * are called, otherwise only the @nb notifier is called. Returns the number of
+ * sent notifications.
+ */
+int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
+{
+        struct ubi_notification nt;
+        int i, count = 0;
+
+        ubi_do_get_device_info(ubi, &nt.di);
+
+        mutex_lock(&ubi->device_mutex);
+        for (i = 0; i < ubi->vtbl_slots; i++) {
+                /*
+                 * Since the @ubi->device is locked, and we are not going to
+                 * change @ubi->volumes, we do not have to lock
+                 * @ubi->volumes_lock.
+                 */
+                if (!ubi->volumes[i])
+                        continue;
+
+                ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
+                if (nb)
+                        nb->notifier_call(nb, ntype, &nt);
+                else
+                        blocking_notifier_call_chain(&ubi_notifiers, ntype,
+                                                     &nt);
+                count += 1;
+        }
+        mutex_unlock(&ubi->device_mutex);
+
+        return count;
+}
+
+/**
+ * ubi_enumerate_volumes - send "add" notification for all existing volumes.
+ * @nb: the notifier to call
+ *
+ * This function walks all UBI devices and volumes and sends the
+ * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
+ * registered notifiers are called, otherwise only the @nb notifier is called.
+ * Returns the number of sent notifications.
+ */
+int ubi_enumerate_volumes(struct notifier_block *nb)
+{
+        int i, count = 0;
+
+        /*
+         * Since the @ubi_devices_mutex is locked, and we are not going to
+         * change @ubi_devices, we do not have to lock @ubi_devices_lock.
+         */
+        for (i = 0; i < UBI_MAX_DEVICES; i++) {
+                struct ubi_device *ubi = ubi_devices[i];
+
+                if (!ubi)
+                        continue;
+                count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
+        }
+
+        return count;
+}
+
+/**
  * ubi_get_device - get UBI device.
  * @ubi_num: UBI device number
  *
@@ -891,6 +979,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
         spin_unlock(&ubi->wl_lock);
 
         ubi_devices[ubi_num] = ubi;
+        ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
         return ubi_num;
 
 out_uif:
@@ -933,13 +1022,13 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
         if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
                 return -EINVAL;
 
-        spin_lock(&ubi_devices_lock);
-        ubi = ubi_devices[ubi_num];
-        if (!ubi) {
-                spin_unlock(&ubi_devices_lock);
+        ubi = ubi_get_device(ubi_num);
+        if (!ubi)
                 return -EINVAL;
-        }
 
+        spin_lock(&ubi_devices_lock);
+        put_device(&ubi->dev);
+        ubi->ref_count -= 1;
         if (ubi->ref_count) {
                 if (!anyway) {
                         spin_unlock(&ubi_devices_lock);
@@ -953,6 +1042,7 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
         spin_unlock(&ubi_devices_lock);
 
         ubi_assert(ubi_num == ubi->ubi_num);
+        ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
         dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
 
         /*