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>

1 files changed, 26 insertions, 12 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 10b9ac46c2d..e8c42bfd12b 100644
--- 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;