UBI: get device when opening volume

When a volume is opened, get its kref via get_device() call.
And put the reference when closing the volume. With this, we
may have a bit saner volume delete.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

3 files changed, 8 insertions, 8 deletions

diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c
index 24344ba3cfe..35d34b675c7 100644
--- a/drivers/mtd/ubi/cdev.c
+++ b/drivers/mtd/ubi/cdev.c
@@ -635,9 +635,12 @@ static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
                 }
 
                 err = ubi_remove_volume(desc);
-                if (err)
-                        ubi_close_volume(desc);
-
+                /*
+                 * The volume is deleted, and the 'struct ubi_volume' object
+                 * will be freed when 'ubi_close_volume()' will call
+                 * 'put_device()'.
+                 */
+                ubi_close_volume(desc);
                 break;
         }
 
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index 8e15002a36c..96f5fef5f3f 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -156,6 +156,7 @@ struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
                 vol->exclusive = 1;
                 break;
         }
+        get_device(&vol->dev);
         spin_unlock(&ubi->volumes_lock);
 
         desc->vol = vol;
@@ -274,6 +275,7 @@ void ubi_close_volume(struct ubi_volume_desc *desc)
         spin_unlock(&vol->ubi->volumes_lock);
 
         kfree(desc);
+        put_device(&vol->dev);
         module_put(THIS_MODULE);
 }
 EXPORT_SYMBOL_GPL(ubi_close_volume);
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c
index ec2dd3c65c4..9dd3689aecd 100644
--- a/drivers/mtd/ubi/vmt.c
+++ b/drivers/mtd/ubi/vmt.c
@@ -435,7 +435,6 @@ int ubi_remove_volume(struct ubi_volume_desc *desc)
         vol->eba_tbl = NULL;
         cdev_del(&vol->cdev);
         volume_sysfs_close(vol);
-        kfree(desc);
 
         spin_lock(&ubi->volumes_lock);
         ubi->rsvd_pebs -= reserved_pebs;
@@ -453,10 +452,6 @@ int ubi_remove_volume(struct ubi_volume_desc *desc)
         spin_unlock(&ubi->volumes_lock);
 
         paranoid_check_volumes(ubi);
-        mutex_unlock(&ubi->volumes_mutex);
-        module_put(THIS_MODULE);
-        return 0;
-
 out:
         mutex_unlock(&ubi->volumes_mutex);
         return err;