[PATCH] bdget_disk()

	New helper - bdget_disk(gendisk, partition)
	invalidate_device() replaced with invalidate_partition(disk, part)

drivers/block/floppy.c

@@ -3885,7 +3885,7 @@ static int floppy_read_block_0(struct gendisk *disk)
 	struct block_device *bdev;
 	int ret;
 
-	bdev = bdget(MKDEV(disk->major, disk->first_minor));
+	bdev = bdget_disk(disk, 0);
 	if (!bdev) {
 		printk("No block device for %s\n", disk->disk_name);
 		BUG();

drivers/block/floppy98.c

@@ -3995,7 +3995,7 @@ static int floppy_read_block_0(struct gendisk *disk)
 	struct block_device *bdev;
 	int ret;
 
-	bdev = bdget(MKDEV(disk->major, disk->first_minor));
+	bdev = bdget_disk(disk, 0);
 	if (!bdev) {
 		printk("No block device for %s\n", disk->disk_name);
 		BUG();

drivers/block/genhd.c

@@ -721,6 +721,17 @@ int bdev_read_only(struct block_device *bdev)
 		return disk->policy;
 }
 
+int invalidate_partition(struct gendisk *disk, int index)
+{
+	int res = 0;
+	struct block_device *bdev = bdget_disk(disk, index);
+	if (bdev)
+		res = __invalidate_device(bdev, 1);
+	bdput(bdev);
+	return res;
+}
+
 EXPORT_SYMBOL(bdev_read_only);
 EXPORT_SYMBOL(set_device_ro);
 EXPORT_SYMBOL(set_disk_ro);
+EXPORT_SYMBOL(invalidate_partition);

drivers/block/ioctl.c

@@ -62,7 +62,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg *arg)
 			if (disk->part[part - 1]->nr_sects == 0)
 				return -ENXIO;
 			/* partition in use? Incomplete check for now. */
-			bdevp = bdget(MKDEV(disk->major, disk->first_minor) + part);
+			bdevp = bdget_disk(disk, part);
 			if (!bdevp)
 				return -ENOMEM;
 			if (bd_claim(bdevp, &holder) < 0) {

drivers/md/dm-ioctl.c

@@ -450,11 +450,11 @@ static int __info(struct mapped_device *md, struct dm_ioctl *param)
 	if (dm_suspended(md))
 		param->flags |= DM_SUSPEND_FLAG;
 
-	param->dev = MKDEV(disk->major, disk->first_minor);
-	bdev = bdget(param->dev);
+	bdev = bdget_disk(disk, 0);
 	if (!bdev)
 		return -ENXIO;
 
+	param->dev = bdev->bd_dev;
 	param->open_count = bdev->bd_openers;
 	bdput(bdev);
 

drivers/md/md.c

@@ -1684,7 +1684,7 @@ static int do_md_stop(mddev_t * mddev, int ro)
 
 		del_timer_sync(&mddev->safemode_timer);
 
-		invalidate_device(mk_kdev(disk->major, disk->first_minor), 1);
+		invalidate_partition(disk, 0);
 
 		if (ro) {
 			err  = -ENXIO;

fs/block_dev.c

@@ -535,7 +535,7 @@ static int do_open(struct block_device *bdev, struct inode *inode, struct file *
 		} else {
 			struct hd_struct *p;
 			struct block_device *whole;
-			whole = bdget(MKDEV(disk->major, disk->first_minor));
+			whole = bdget_disk(disk, 0);
 			ret = -ENOMEM;
 			if (!whole)
 				goto out_first;

fs/inode.c

@@ -365,16 +365,6 @@ int __invalidate_device(struct block_device *bdev, int do_sync)
 	return res;
 }
 
-int invalidate_device(kdev_t dev, int do_sync)
-{
-	int res = 0;
-	struct block_device *bdev = bdget(kdev_t_to_nr(dev));
-	if (bdev)
-		res = __invalidate_device(bdev, do_sync);
-	bdput(bdev);
-	return res;
-}
-
 static int can_unuse(struct inode *inode)
 {
 	if (inode->i_state)

fs/partitions/check.c

@@ -311,7 +311,7 @@ void register_disk(struct gendisk *disk)
 	if (!get_capacity(disk))
 		return;
 
-	bdev = bdget(MKDEV(disk->major, disk->first_minor));
+	bdev = bdget_disk(disk, 0);
 	if (blkdev_get(bdev, FMODE_READ, 0, BDEV_RAW) < 0)
 		return;
 	state = check_partition(disk, bdev);
@@ -336,13 +336,12 @@ void register_disk(struct gendisk *disk)
 
 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 {
-	kdev_t dev = to_kdev_t(bdev->bd_dev);
 	struct parsed_partitions *state;
 	int p, res;
 
 	if (bdev->bd_part_count)
 		return -EBUSY;
-	res = invalidate_device(dev, 1);
+	res = invalidate_partition(disk, 0);
 	if (res)
 		return res;
 	bdev->bd_invalidated = 0;
@@ -391,18 +390,14 @@ unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 
 void del_gendisk(struct gendisk *disk)
 {
-	int max_p = disk->minors;
-	kdev_t devp;
 	int p;
 
 	/* invalidate stuff */
-	for (p = max_p - 1; p > 0; p--) {
-		devp = mk_kdev(disk->major,disk->first_minor + p);
-		invalidate_device(devp, 1);
+	for (p = disk->minors - 1; p > 0; p--) {
+		invalidate_partition(disk, p);
 		delete_partition(disk, p);
 	}
-	devp = mk_kdev(disk->major,disk->first_minor);
-	invalidate_device(devp, 1);
+	invalidate_partition(disk, 0);
 	disk->capacity = 0;
 	disk->flags &= ~GENHD_FL_UP;
 	unlink_gendisk(disk);

include/linux/fs.h

@@ -1105,7 +1105,7 @@ extern int fs_may_remount_ro(struct super_block *);
 extern int check_disk_change(struct block_device *);
 extern int invalidate_inodes(struct super_block *);
 extern int __invalidate_device(struct block_device *, int);
-extern int invalidate_device(kdev_t, int);
+extern int invalidate_partition(struct gendisk *, int);
 unsigned long invalidate_mapping_pages(struct address_space *mapping,
 					pgoff_t start, pgoff_t end);
 unsigned long invalidate_inode_pages(struct address_space *mapping);

include/linux/genhd.h

@@ -367,6 +367,11 @@ extern void blk_register_region(dev_t dev, unsigned long range,
 			void *data);
 extern void blk_unregister_region(dev_t dev, unsigned long range);
 
+static inline struct block_device *bdget_disk(struct gendisk *disk, int index)
+{
+	return bdget(MKDEV(disk->major, disk->first_minor) + index);
+}
+
 #endif
 
 #endif

kernel/ksyms.c

@@ -188,7 +188,6 @@ EXPORT_SYMBOL(files_lock);
 EXPORT_SYMBOL(check_disk_change);
 EXPORT_SYMBOL(invalidate_bdev);
 EXPORT_SYMBOL(invalidate_inodes);
-EXPORT_SYMBOL(invalidate_device);
 EXPORT_SYMBOL(__invalidate_device);
 EXPORT_SYMBOL(invalidate_inode_pages);
 EXPORT_SYMBOL_GPL(invalidate_inode_pages2);