[PATCH 1/3] block: introduce device_add_disk()

[Dan Williams]

In preparation for removing the ->driverfs_dev member of a gendisk, add
an api that takes the parent device as a parameter to add_disk().

Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
---
 block/genhd.c         |   22 ++++++++++------------
 include/linux/genhd.h |    8 +++++++-
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index eb05dfc1dffe..3fa2654ada52 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -506,7 +506,7 @@ static int exact_lock(dev_t devt, void *data)
        return 0;
 }
 
-static void register_disk(struct gendisk *disk)
+static void register_disk(struct device *parent, struct gendisk *disk)
 {
        struct device *ddev = disk_to_dev(disk);
        struct block_device *bdev;
@@ -514,7 +514,7 @@ static void register_disk(struct gendisk *disk)
        struct hd_struct *part;
        int err;
 
-       ddev->parent = disk->driverfs_dev;
+       ddev->parent = parent;
 
        dev_set_name(ddev, "%s", disk->disk_name);
 
@@ -573,7 +573,8 @@ exit:
 }
 
 /**
- * add_disk - add partitioning information to kernel list
+ * device_add_disk - add partitioning information to kernel list
+ * @parent: parent device for the disk
  * @disk: per-device partitioning information
  *
  * This function registers the partitioning information in @disk
@@ -581,7 +582,7 @@ exit:
  *
  * FIXME: error handling
  */
-void add_disk(struct gendisk *disk)
+int device_add_disk(struct device *parent, struct gendisk *disk)
 {
        struct backing_dev_info *bdi;
        dev_t devt;
@@ -597,10 +598,8 @@ void add_disk(struct gendisk *disk)
        disk->flags |= GENHD_FL_UP;
 
        retval = blk_alloc_devt(&disk->part0, &devt);
-       if (retval) {
-               WARN_ON(1);
-               return;
-       }
+       if (retval)
+               return retval;
        disk_to_dev(disk)->devt = devt;
 
        /* ->major and ->first_minor aren't supposed to be
@@ -617,7 +616,7 @@ void add_disk(struct gendisk *disk)
 
        blk_register_region(disk_devt(disk), disk->minors, NULL,
                            exact_match, exact_lock, disk);
-       register_disk(disk);
+       register_disk(parent, disk);
        blk_register_queue(disk);
 
        /*
@@ -628,12 +627,11 @@ void add_disk(struct gendisk *disk)
 
        retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
                                   "bdi");
-       WARN_ON(retval);
-
        disk_add_events(disk);
        blk_integrity_add(disk);
+       return retval;
 }
-EXPORT_SYMBOL(add_disk);
+EXPORT_SYMBOL(device_add_disk);
 
 void del_gendisk(struct gendisk *disk)
 {
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 5c706765404a..6fa03fe589ad 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -431,7 +431,13 @@ static inline void free_part_info(struct hd_struct *part)
 extern void part_round_stats(int cpu, struct hd_struct *part);
 
 /* block/genhd.c */
-extern void add_disk(struct gendisk *disk);
+extern int device_add_disk(struct device *parent, struct gendisk *disk);
+static inline void add_disk(struct gendisk *disk)
+{
+       /* temporary while we convert callers to device_add_disk */
+       WARN_ON(device_add_disk(disk->driverfs_dev, disk) != 0);
+}
+
 extern void del_gendisk(struct gendisk *gp);
 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);