scsi: sd: Consolidate compat ioctl handling

Merge the native and compat ioctl handlers into a single one using
in_compat_syscall(), and also simplify the calling conventions by merging
sd_ioctl_common() into sd_ioctl().

Link: https://lore.kernel.org/r/20210724072033.1284840-4-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/sd.c

@@ -1530,11 +1530,11 @@ static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 }
 
 /**
- *	sd_ioctl_common - process an ioctl
+ *	sd_ioctl - process an ioctl
  *	@bdev: target block device
  *	@mode: FMODE_* mask
  *	@cmd: ioctl command number
- *	@p: this is third argument given to ioctl(2) system call.
+ *	@arg: this is third argument given to ioctl(2) system call.
  *	Often contains a pointer.
  *
  *	Returns 0 if successful (some ioctls return positive numbers on
@@ -1543,12 +1543,13 @@ static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
  *	Note: most ioctls are forward onto the block subsystem or further
  *	down in the scsi subsystem.
  **/
-static int sd_ioctl_common(struct block_device *bdev, fmode_t mode,
-			   unsigned int cmd, void __user *p)
+static int sd_ioctl(struct block_device *bdev, fmode_t mode,
+		    unsigned int cmd, unsigned long arg)
 {
 	struct gendisk *disk = bdev->bd_disk;
 	struct scsi_disk *sdkp = scsi_disk(disk);
 	struct scsi_device *sdp = sdkp->device;
+	void __user *p = (void __user *)arg;
 	int error;
     
 	SCSI_LOG_IOCTL(1, sd_printk(KERN_INFO, sdkp, "sd_ioctl: disk=%s, "
@@ -1567,7 +1568,7 @@ static int sd_ioctl_common(struct block_device *bdev, fmode_t mode,
 	error = scsi_ioctl_block_when_processing_errors(sdp, cmd,
 			(mode & FMODE_NDELAY) != 0);
 	if (error)
-		goto out;
+		return error;
 
 	if (is_sed_ioctl(cmd))
 		return sed_ioctl(sdkp->opal_dev, cmd, p);
@@ -1578,16 +1579,18 @@ static int sd_ioctl_common(struct block_device *bdev, fmode_t mode,
 	 * resolved.
 	 */
 	switch (cmd) {
-		case SCSI_IOCTL_GET_IDLUN:
-		case SCSI_IOCTL_GET_BUS_NUMBER:
-			error = scsi_ioctl(sdp, cmd, p);
-			break;
-		default:
-			error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
-			break;
+	case SCSI_IOCTL_GET_IDLUN:
+	case SCSI_IOCTL_GET_BUS_NUMBER:
+		break;
+	default:
+		error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
+		if (error != -ENOTTY)
+			return error;
 	}
-out:
-	return error;
+
+	if (in_compat_syscall())
+		return scsi_compat_ioctl(sdp, cmd, p);
+	return scsi_ioctl(sdp, cmd, p);
 }
 
 static void set_media_not_present(struct scsi_disk *sdkp)
@@ -1770,34 +1773,6 @@ static void sd_rescan(struct device *dev)
 	sd_revalidate_disk(sdkp->disk);
 }
 
-static int sd_ioctl(struct block_device *bdev, fmode_t mode,
-		    unsigned int cmd, unsigned long arg)
-{
-	void __user *p = (void __user *)arg;
-	int ret;
-
-	ret = sd_ioctl_common(bdev, mode, cmd, p);
-	if (ret != -ENOTTY)
-		return ret;
-
-	return scsi_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p);
-}
-
-#ifdef CONFIG_COMPAT
-static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
-			   unsigned int cmd, unsigned long arg)
-{
-	void __user *p = compat_ptr(arg);
-	int ret;
-
-	ret = sd_ioctl_common(bdev, mode, cmd, p);
-	if (ret != -ENOTTY)
-		return ret;
-
-	return scsi_compat_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p);
-}
-#endif
-
 static char sd_pr_type(enum pr_type type)
 {
 	switch (type) {
@@ -1898,9 +1873,7 @@ static const struct block_device_operations sd_fops = {
 	.release		= sd_release,
 	.ioctl			= sd_ioctl,
 	.getgeo			= sd_getgeo,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl		= sd_compat_ioctl,
-#endif
+	.compat_ioctl		= blkdev_compat_ptr_ioctl,
 	.check_events		= sd_check_events,
 	.unlock_native_capacity	= sd_unlock_native_capacity,
 	.report_zones		= sd_zbc_report_zones,