UBI: block: Add support for the UBI_VOLUME_UPDATED notification

Static volumes can change its 'used_bytes' when they get updated,
and so the block interface must listen to the UBI_VOLUME_UPDATED
notification to resize the block device accordingly.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: stable@vger.kernel.org # v3.15+

1 files changed, 14 insertions, 2 deletions

diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 581784485376..8876c7d3d712 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -524,8 +524,12 @@ static int ubiblock_resize(struct ubi_volume_info *vi)
         }
 
         mutex_lock(&dev->dev_mutex);
-        set_capacity(dev->gd, disk_capacity);
-        ubi_msg("%s resized to %lld bytes", dev->gd->disk_name, vi->used_bytes);
+
+        if (get_capacity(dev->gd) != disk_capacity) {
+                set_capacity(dev->gd, disk_capacity);
+                ubi_msg("%s resized to %lld bytes", dev->gd->disk_name,
+                        vi->used_bytes);
+        }
         mutex_unlock(&dev->dev_mutex);
         mutex_unlock(&devices_mutex);
         return 0;
@@ -549,6 +553,14 @@ static int ubiblock_notify(struct notifier_block *nb,
         case UBI_VOLUME_RESIZED:
                 ubiblock_resize(&nt->vi);
                 break;
+        case UBI_VOLUME_UPDATED:
+                /*
+                 * If the volume is static, a content update might mean the
+                 * size (i.e. used_bytes) was also changed.
+                 */
+                if (nt->vi.vol_type == UBI_STATIC_VOLUME)
+                        ubiblock_resize(&nt->vi);
+                break;
         default:
                 break;
         }