Re: [PATCH] Change paride driver to use unlocked_ioctl instead of ioctl

[Nikanth Karthikesan <knikanth@suse.de>]

Sorry missed the function prototype and includes earlier.
Here is the corrected patch. Build tested.

The ioctl handler is called with the BKL held. Registering
unlocked_ioctl handler instead of registering ioctl handler.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>

---

diff --git a/drivers/block/paride/pt.c b/drivers/block/paride/pt.c
index b91accf..860b946 100644
--- a/drivers/block/paride/pt.c
+++ b/drivers/block/paride/pt.c
@@ -146,6 +146,7 @@ static int (*drives[4])[6] = {&drive0, &drive1, &drive2,
&drive3};
 #include <linux/mtio.h>
 #include <linux/device.h>
 #include <linux/sched.h>	/* current, TASK_*, schedule_timeout() */
+#include <linux/smp_lock.h>

 #include <asm/uaccess.h>

@@ -189,8 +190,8 @@ module_param_array(drive3, int, NULL, 0);
 #define ATAPI_LOG_SENSE		0x4d

 static int pt_open(struct inode *inode, struct file *file);
-static int pt_ioctl(struct inode *inode, struct file *file,
-		    unsigned int cmd, unsigned long arg);
+static long pt_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg);
 static int pt_release(struct inode *inode, struct file *file);
 static ssize_t pt_read(struct file *filp, char __user *buf,
 		       size_t count, loff_t * ppos);
@@ -236,7 +237,7 @@ static const struct file_operations pt_fops = {
 	.owner = THIS_MODULE,
 	.read = pt_read,
 	.write = pt_write,
-	.ioctl = pt_ioctl,
+	.unlocked_ioctl = pt_ioctl,
 	.open = pt_open,
 	.release = pt_release,
 };
@@ -685,36 +686,44 @@ out:
 	return err;
 }

-static int pt_ioctl(struct inode *inode, struct file *file,
-	 unsigned int cmd, unsigned long arg)
+static long pt_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
 {
 	struct pt_unit *tape = file->private_data;
 	struct mtop __user *p = (void __user *)arg;
 	struct mtop mtop;

+	lock_kernel();
+
 	switch (cmd) {
 	case MTIOCTOP:
-		if (copy_from_user(&mtop, p, sizeof(struct mtop)))
+		if (copy_from_user(&mtop, p, sizeof(struct mtop))) {
+			unlock_kernel();
 			return -EFAULT;
+		}

 		switch (mtop.mt_op) {

 		case MTREW:
 			pt_rewind(tape);
+			unlock_kernel();
 			return 0;

 		case MTWEOF:
 			pt_write_fm(tape);
+			unlock_kernel();
 			return 0;

 		default:
 			printk("%s: Unimplemented mt_op %d\n", tape->name,
 			       mtop.mt_op);
+			unlock_kernel();
 			return -EINVAL;
 		}

 	default:
 		printk("%s: Unimplemented ioctl 0x%x\n", tape->name, cmd);
+		unlock_kernel();
 		return -EINVAL;

 	}