[SCSI] ch: Convert to use unlocked_ioctl

As of now, compat_ioctl already runs without the BKL, whereas ioctl runs
with the BKL. This patch first converts changer_fops to use a .unlocked_ioctl
member. It applies the same locking rationale than ch_ioctl_compat() uses
to ch_ioctl().
Signed-off-by: NMathieu Segaud <mathieu.segaud@regala.cx>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/ch.c

@@ -92,8 +92,7 @@ static int  ch_probe(struct device *);
 static int  ch_remove(struct device *);
 static int  ch_open(struct inode * inode, struct file * filp);
 static int  ch_release(struct inode * inode, struct file * filp);
-static int  ch_ioctl(struct inode * inode, struct file * filp,
-		     unsigned int cmd, unsigned long arg);
+static long ch_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 #ifdef CONFIG_COMPAT
 static long ch_ioctl_compat(struct file * filp,
 			    unsigned int cmd, unsigned long arg);
@@ -133,7 +132,7 @@ static const struct file_operations changer_fops =
 	.owner		= THIS_MODULE,
 	.open		= ch_open,
 	.release	= ch_release,
-	.ioctl        = ch_ioctl,
+	.unlocked_ioctl	= ch_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ch_ioctl_compat,
 #endif
@@ -626,7 +625,7 @@ ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
 	return 0;
 }
 
-static int ch_ioctl(struct inode * inode, struct file * file,
+static long ch_ioctl(struct file *file,
 		    unsigned int cmd, unsigned long arg)
 {
 	scsi_changer *ch = file->private_data;
@@ -887,8 +886,7 @@ static long ch_ioctl_compat(struct file * file,
 	case CHIOINITELEM:
 	case CHIOSVOLTAG:
 		/* compatible */
-		return ch_ioctl(NULL /* inode, unused */,
-				file, cmd, arg);
+		return ch_ioctl(file, cmd, arg);
 	case CHIOGSTATUS32:
 	{
 		struct changer_element_status32 ces32;