Merge tag 'drm-misc-fixes-2020-03-26' of git://anongit.freedesktop.org/drm/drm-misc...

[linux-2.6-microblaze.git] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index ff62689..9c2e13c 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -301,6 +301,42 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
 }
 EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
 
+/**
+ * disk_has_partitions
+ * @disk: gendisk of interest
+ *
+ * Walk through the partition table and check if valid partition exists.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * True if the gendisk has at least one valid non-zero size partition.
+ * Otherwise false.
+ */
+bool disk_has_partitions(struct gendisk *disk)
+{
+       struct disk_part_tbl *ptbl;
+       int i;
+       bool ret = false;
+
+       rcu_read_lock();
+       ptbl = rcu_dereference(disk->part_tbl);
+
+       /* Iterate partitions skipping the whole device at index 0 */
+       for (i = 1; i < ptbl->len; i++) {
+               if (rcu_dereference(ptbl->part[i])) {
+                       ret = true;
+                       break;
+               }
+       }
+
+       rcu_read_unlock();
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(disk_has_partitions);
+
 /*
  * Can be deleted altogether. Later.
  *