block: make blk_lookup_devt use the class iterator function

Use the proper class iterator function instead of mucking around in the
internals of the class structures.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/block/genhd.c b/block/genhd.c
index 10b9ac4..e8c42bf 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -677,24 +677,38 @@ void genhd_media_change_notify(struct gendisk *disk)
 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 #endif  /*  0  */
 
+struct find_block {
+       const char *name;
+       int part;
+};
+
+static int match_id(struct device *dev, void *data)
+{
+       struct find_block *find = data;
+
+       if (dev->type != &disk_type)
+               return 0;
+       if (strcmp(dev->bus_id, find->name) == 0) {
+               struct gendisk *disk = dev_to_disk(dev);
+               if (find->part < disk->minors)
+                       return 1;
+       }
+       return 0;
+}
+
 dev_t blk_lookup_devt(const char *name, int part)
 {
        struct device *dev;
        dev_t devt = MKDEV(0, 0);
+       struct find_block find;
 
        mutex_lock(&block_class_lock);
-       list_for_each_entry(dev, &block_class.devices, node) {
-               if (dev->type != &disk_type)
-                       continue;
-               if (strcmp(dev->bus_id, name) == 0) {
-                       struct gendisk *disk = dev_to_disk(dev);
-
-                       if (part < disk->minors)
-                               devt = MKDEV(MAJOR(dev->devt),
-                                            MINOR(dev->devt) + part);
-                       break;
-               }
-       }
+       find.name = name;
+       find.part = part;
+       dev = class_find_device(&block_class, NULL, (void *)&find, match_id);
+       if (dev)
+               devt = MKDEV(MAJOR(dev->devt),
+                            MINOR(dev->devt) + part);
        mutex_unlock(&block_class_lock);
 
        return devt;