scsi: ch: Consolidate compat ioctl handling

Merge the native and compat ioctl handlers into a single one using
in_compat_syscall().

Link: https://lore.kernel.org/r/20210724072033.1284840-5-hch@lst.deSigned-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ch.c

@@ -618,6 +618,12 @@ ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
 	return 0;
 }
 
+struct changer_element_status32 {
+	int		ces_type;
+	compat_uptr_t	ces_data;
+};
+#define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
+
 static long ch_ioctl(struct file *file,
 		    unsigned int cmd, unsigned long arg)
 {
@@ -748,7 +754,20 @@ static long ch_ioctl(struct file *file,
 
 		return ch_gstatus(ch, ces.ces_type, ces.ces_data);
 	}
+#ifdef CONFIG_COMPAT
+	case CHIOGSTATUS32:
+	{
+		struct changer_element_status32 ces32;
 
+		if (copy_from_user(&ces32, argp, sizeof(ces32)))
+			return -EFAULT;
+		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
+			return -EINVAL;
+
+		return ch_gstatus(ch, ces32.ces_type,
+				  compat_ptr(ces32.ces_data));
+	}
+#endif
 	case CHIOGELEM:
 	{
 		struct changer_get_element cge;
@@ -858,59 +877,13 @@ static long ch_ioctl(struct file *file,
 	}
 
 	default:
+		if (in_compat_syscall())
+			return scsi_compat_ioctl(ch->device, cmd, argp);
 		return scsi_ioctl(ch->device, cmd, argp);
 
 	}
 }
 
-#ifdef CONFIG_COMPAT
-
-struct changer_element_status32 {
-	int		ces_type;
-	compat_uptr_t	ces_data;
-};
-#define CHIOGSTATUS32  _IOW('c', 8,struct changer_element_status32)
-
-static long ch_ioctl_compat(struct file * file,
-			    unsigned int cmd, unsigned long arg)
-{
-	scsi_changer *ch = file->private_data;
-	int retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
-							file->f_flags & O_NDELAY);
-	if (retval)
-		return retval;
-
-	switch (cmd) {
-	case CHIOGPARAMS:
-	case CHIOGVPARAMS:
-	case CHIOPOSITION:
-	case CHIOMOVE:
-	case CHIOEXCHANGE:
-	case CHIOGELEM:
-	case CHIOINITELEM:
-	case CHIOSVOLTAG:
-		/* compatible */
-		return ch_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
-	case CHIOGSTATUS32:
-	{
-		struct changer_element_status32 ces32;
-		unsigned char __user *data;
-
-		if (copy_from_user(&ces32, (void __user *)arg, sizeof (ces32)))
-			return -EFAULT;
-		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
-			return -EINVAL;
-
-		data = compat_ptr(ces32.ces_data);
-		return ch_gstatus(ch, ces32.ces_type, data);
-	}
-	default:
-		return scsi_compat_ioctl(ch->device, cmd, compat_ptr(arg));
-
-	}
-}
-#endif
-
 /* ------------------------------------------------------------------------ */
 
 static int ch_probe(struct device *dev)
@@ -1015,9 +988,7 @@ static const struct file_operations changer_fops = {
 	.open		= ch_open,
 	.release	= ch_release,
 	.unlocked_ioctl	= ch_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl	= ch_ioctl_compat,
-#endif
+	.compat_ioctl	= compat_ptr_ioctl,
 	.llseek		= noop_llseek,
 };