block,ide: simplify bdops->set_capacity() to ->unlock_native_capacity()

bdops->set_capacity() is unnecessarily generic.  All that's required
is a simple one way notification to lower level driver telling it to
try to unlock native capacity.  There's no reason to pass in target
capacity or return the new capacity.  The former is always the
inherent native capacity and the latter can be handled via the usual
device resize / revalidation path.  In fact, the current API is always
used that way.

Replace ->set_capacity() with ->unlock_native_capacity() which take
only @disk and doesn't return anything.  IDE which is the only current
user of the API is converted accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

drivers/ide/ide-disk.c

@@ -407,32 +407,24 @@ static int ide_disk_get_capacity(ide_drive_t *drive)
 	return 0;
 }
 
-static u64 ide_disk_set_capacity(ide_drive_t *drive, u64 capacity)
+static void ide_disk_unlock_native_capacity(ide_drive_t *drive)
 {
-	u64 set = min(capacity, drive->probed_capacity);
 	u16 *id = drive->id;
 	int lba48 = ata_id_lba48_enabled(id);
 
 	if ((drive->dev_flags & IDE_DFLAG_LBA) == 0 ||
 	    ata_id_hpa_enabled(id) == 0)
-		goto out;
+		return;
 
 	/*
 	 * according to the spec the SET MAX ADDRESS command shall be
 	 * immediately preceded by a READ NATIVE MAX ADDRESS command
 	 */
-	capacity = ide_disk_hpa_get_native_capacity(drive, lba48);
-	if (capacity == 0)
-		goto out;
+	if (!ide_disk_hpa_get_native_capacity(drive, lba48))
+		return;
 
-	set = ide_disk_hpa_set_capacity(drive, set, lba48);
-	if (set) {
-		/* needed for ->resume to disable HPA */
-		drive->dev_flags |= IDE_DFLAG_NOHPA;
-		return set;
-	}
-out:
-	return drive->capacity64;
+	if (ide_disk_hpa_set_capacity(drive, drive->probed_capacity, lba48))
+		drive->dev_flags |= IDE_DFLAG_NOHPA; /* disable HPA on resume */
 }
 
 static void idedisk_prepare_flush(struct request_queue *q, struct request *rq)
@@ -783,13 +775,13 @@ static int ide_disk_set_doorlock(ide_drive_t *drive, struct gendisk *disk,
 }
 
 const struct ide_disk_ops ide_ata_disk_ops = {
-	.check		= ide_disk_check,
-	.set_capacity	= ide_disk_set_capacity,
-	.get_capacity	= ide_disk_get_capacity,
-	.setup		= ide_disk_setup,
-	.flush		= ide_disk_flush,
-	.init_media	= ide_disk_init_media,
-	.set_doorlock	= ide_disk_set_doorlock,
-	.do_request	= ide_do_rw_disk,
-	.ioctl		= ide_disk_ioctl,
+	.check			= ide_disk_check,
+	.unlock_native_capacity	= ide_disk_unlock_native_capacity,
+	.get_capacity		= ide_disk_get_capacity,
+	.setup			= ide_disk_setup,
+	.flush			= ide_disk_flush,
+	.init_media		= ide_disk_init_media,
+	.set_doorlock		= ide_disk_set_doorlock,
+	.do_request		= ide_do_rw_disk,
+	.ioctl			= ide_disk_ioctl,
 };

drivers/ide/ide-gd.c

@@ -288,17 +288,14 @@ static int ide_gd_media_changed(struct gendisk *disk)
 	return ret;
 }
 
-static unsigned long long ide_gd_set_capacity(struct gendisk *disk,
-					      unsigned long long capacity)
+static void ide_gd_unlock_native_capacity(struct gendisk *disk)
 {
 	struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj);
 	ide_drive_t *drive = idkp->drive;
 	const struct ide_disk_ops *disk_ops = drive->disk_ops;
 
-	if (disk_ops->set_capacity)
-		return disk_ops->set_capacity(drive, capacity);
-
-	return drive->capacity64;
+	if (disk_ops->unlock_native_capacity)
+		disk_ops->unlock_native_capacity(drive);
 }
 
 static int ide_gd_revalidate_disk(struct gendisk *disk)
@@ -329,7 +326,7 @@ static const struct block_device_operations ide_gd_ops = {
 	.locked_ioctl		= ide_gd_ioctl,
 	.getgeo			= ide_gd_getgeo,
 	.media_changed		= ide_gd_media_changed,
-	.set_capacity		= ide_gd_set_capacity,
+	.unlock_native_capacity	= ide_gd_unlock_native_capacity,
 	.revalidate_disk	= ide_gd_revalidate_disk
 };
 

fs/partitions/check.c

@@ -601,10 +601,10 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 			       "%s: p%d size %llu exceeds device capacity, ",
 			       disk->disk_name, p, (unsigned long long) size);
 
-			if (bdops->set_capacity &&
+			if (bdops->unlock_native_capacity &&
 			    (disk->flags & GENHD_FL_NATIVE_CAPACITY) == 0) {
 				printk(KERN_CONT "enabling native capacity\n");
-				bdops->set_capacity(disk, ~0ULL);
+				bdops->unlock_native_capacity(disk);
 				disk->flags |= GENHD_FL_NATIVE_CAPACITY;
 				/* free state and restart */
 				kfree(state);

include/linux/blkdev.h

@@ -1330,8 +1330,7 @@ struct block_device_operations {
 	int (*direct_access) (struct block_device *, sector_t,
 						void **, unsigned long *);
 	int (*media_changed) (struct gendisk *);
-	unsigned long long (*set_capacity) (struct gendisk *,
-						unsigned long long);
+	void (*unlock_native_capacity) (struct gendisk *);
 	int (*revalidate_disk) (struct gendisk *);
 	int (*getgeo)(struct block_device *, struct hd_geometry *);
 	struct module *owner;

include/linux/ide.h

@@ -362,7 +362,7 @@ struct ide_drive_s;
 struct ide_disk_ops {
 	int		(*check)(struct ide_drive_s *, const char *);
 	int		(*get_capacity)(struct ide_drive_s *);
-	u64		(*set_capacity)(struct ide_drive_s *, u64);
+	void		(*unlock_native_capacity)(struct ide_drive_s *);
 	void		(*setup)(struct ide_drive_s *);
 	void		(*flush)(struct ide_drive_s *);
 	int		(*init_media)(struct ide_drive_s *, struct gendisk *);