1 files changed, 92 insertions, 16 deletions

diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 2675207c5fe3..88a72e9c8beb 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -26,6 +26,24 @@
 #include "ubi.h"
 
 /**
+ * ubi_do_get_device_info - get information about UBI device.
+ * @ubi: UBI device description object
+ * @di: the information is stored here
+ *
+ * This function is the same as 'ubi_get_device_info()', but it assumes the UBI
+ * device is locked and cannot disappear.
+ */
+void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
+{
+        di->ubi_num = ubi->ubi_num;
+        di->leb_size = ubi->leb_size;
+        di->min_io_size = ubi->min_io_size;
+        di->ro_mode = ubi->ro_mode;
+        di->cdev = ubi->cdev.dev;
+}
+EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
+
+/**
  * ubi_get_device_info - get information about UBI device.
  * @ubi_num: UBI device number
  * @di: the information is stored here
@@ -39,33 +57,24 @@ int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
 
         if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
                 return -EINVAL;
-
         ubi = ubi_get_device(ubi_num);
         if (!ubi)
                 return -ENODEV;
-
-        di->ubi_num = ubi->ubi_num;
-        di->leb_size = ubi->leb_size;
-        di->min_io_size = ubi->min_io_size;
-        di->ro_mode = ubi->ro_mode;
-        di->cdev = ubi->cdev.dev;
-
+        ubi_do_get_device_info(ubi, di);
         ubi_put_device(ubi);
         return 0;
 }
 EXPORT_SYMBOL_GPL(ubi_get_device_info);
 
 /**
- * ubi_get_volume_info - get information about UBI volume.
- * @desc: volume descriptor
+ * ubi_do_get_volume_info - get information about UBI volume.
+ * @ubi: UBI device description object
+ * @vol: volume description object
  * @vi: the information is stored here
  */
-void ubi_get_volume_info(struct ubi_volume_desc *desc,
-                         struct ubi_volume_info *vi)
+void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
+                            struct ubi_volume_info *vi)
 {
-        const struct ubi_volume *vol = desc->vol;
-        const struct ubi_device *ubi = vol->ubi;
-
         vi->vol_id = vol->vol_id;
         vi->ubi_num = ubi->ubi_num;
         vi->size = vol->reserved_pebs;
@@ -79,6 +88,17 @@ void ubi_get_volume_info(struct ubi_volume_desc *desc,
         vi->name = vol->name;
         vi->cdev = vol->cdev.dev;
 }
+
+/**
+ * ubi_get_volume_info - get information about UBI volume.
+ * @desc: volume descriptor
+ * @vi: the information is stored here
+ */
+void ubi_get_volume_info(struct ubi_volume_desc *desc,
+                         struct ubi_volume_info *vi)
+{
+        ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
+}
 EXPORT_SYMBOL_GPL(ubi_get_volume_info);
 
 /**
@@ -561,7 +581,7 @@ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
 EXPORT_SYMBOL_GPL(ubi_leb_unmap);
 
 /**
- * ubi_leb_map - map logical erasblock to a physical eraseblock.
+ * ubi_leb_map - map logical eraseblock to a physical eraseblock.
  * @desc: volume descriptor
  * @lnum: logical eraseblock number
  * @dtype: expected data type
@@ -659,3 +679,59 @@ int ubi_sync(int ubi_num)
         return 0;
 }
 EXPORT_SYMBOL_GPL(ubi_sync);
+
+BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
+
+/**
+ * ubi_register_volume_notifier - register a volume notifier.
+ * @nb: the notifier description object
+ * @ignore_existing: if non-zero, do not send "added" notification for all
+ *                   already existing volumes
+ *
+ * This function registers a volume notifier, which means that
+ * 'nb->notifier_call()' will be invoked when an UBI  volume is created,
+ * removed, re-sized, re-named, or updated. The first argument of the function
+ * is the notification type. The second argument is pointer to a
+ * &struct ubi_notification object which describes the notification event.
+ * Using UBI API from the volume notifier is prohibited.
+ *
+ * This function returns zero in case of success and a negative error code
+ * in case of failure.
+ */
+int ubi_register_volume_notifier(struct notifier_block *nb,
+                                 int ignore_existing)
+{
+        int err;
+
+        err = blocking_notifier_chain_register(&ubi_notifiers, nb);
+        if (err != 0)
+                return err;
+        if (ignore_existing)
+                return 0;
+
+        /*
+         * We are going to walk all UBI devices and all volumes, and
+         * notify the user about existing volumes by the %UBI_VOLUME_ADDED
+         * event. We have to lock the @ubi_devices_mutex to make sure UBI
+         * devices do not disappear.
+         */
+        mutex_lock(&ubi_devices_mutex);
+        ubi_enumerate_volumes(nb);
+        mutex_unlock(&ubi_devices_mutex);
+
+        return err;
+}
+EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
+
+/**
+ * ubi_unregister_volume_notifier - unregister the volume notifier.
+ * @nb: the notifier description object
+ *
+ * This function unregisters volume notifier @nm and returns zero in case of
+ * success and a negative error code in case of failure.
+ */
+int ubi_unregister_volume_notifier(struct notifier_block *nb)
+{
+        return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
+}
+EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);