block: introduce partition 0

[mirror_ubuntu-bionic-kernel.git] / include / linux / genhd.h

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index e4e18c509ac538acc2794dbc741e1c56b0822f6c..9e866a2aee5029ac71de99ccdbd13d674594f28c 100644 (file)
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -127,12 +127,13 @@ struct gendisk {
 
        char disk_name[32];             /* name of major driver */
 
-       /* Array of pointers to partitions indexed by partno - 1.
+       /* Array of pointers to partitions indexed by partno.
         * Protected with matching bdev lock but stat and other
         * non-critical accesses use RCU.  Always access through
         * helpers.
         */
        struct hd_struct **__part;
+       struct hd_struct part0;
 
        struct block_device_operations *fops;
        struct request_queue *queue;
@@ -171,7 +172,12 @@ static inline struct gendisk *part_to_disk(struct hd_struct *part)
 
 static inline int disk_max_parts(struct gendisk *disk)
 {
-       return disk->minors + disk->ext_minors - 1;
+       return disk->minors + disk->ext_minors;
+}
+
+static inline bool disk_partitionable(struct gendisk *disk)
+{
+       return disk_max_parts(disk) > 1;
 }
 
 static inline dev_t disk_devt(struct gendisk *disk)
@@ -197,6 +203,7 @@ static inline void disk_put_part(struct hd_struct *part)
  */
 #define DISK_PITER_REVERSE     (1 << 0) /* iterate in the reverse direction */
 #define DISK_PITER_INCL_EMPTY  (1 << 1) /* include 0-sized parts */
+#define DISK_PITER_INCL_PART0  (1 << 2) /* include partition 0 */
 
 struct disk_part_iter {
        struct gendisk          *disk;