On Wed, 2008-01-09 at 03:23 -0500, Valdis.Kletnieks@xxxxxx wrote:
> On Wed, 09 Jan 2008 08:06:20 GMT, Christoph Hellwig said:
>
> > It's generally considered good style to only have as few as possible
> > return values. And this is especially important when returning from
> > a section that's under a lock. So in this case it would be much better
> > if you changes this function to have a local 'int error' variable
> > and then just do
> >
> > error = -EFOO;
> > goto out_unlock;
agreed. resending the patch
> I think Christoph meant to say "as few as possible return locations". One
> should write the code to have as many different return values as are
> meaningful, but return them from as few places as possible - which is what the
> "assign error and goto end" paradigm does...
>
Is this following coding style, fine?
The ioctl handler is called with the BKL held. Registering
unlocked_ioctl handler instead of registering ioctl handler.
Signed-off-by: Nikanth Karthikesan <knikanth@xxxxxxx>
---
diff --git a/drivers/block/paride/pt.c b/drivers/block/paride/pt.c
index b91accf..17f32f0 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,
};
@@ -685,39 +686,47 @@ 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;
+ long err = 0;
+
+ lock_kernel();
switch (cmd) {
case MTIOCTOP:
- if (copy_from_user(&mtop, p, sizeof(struct mtop)))
- return -EFAULT;
+ if (copy_from_user(&mtop, p, sizeof(struct mtop))) {
+ err = -EFAULT;
+ break;
+ }
switch (mtop.mt_op) {
case MTREW:
pt_rewind(tape);
- return 0;
+ break;
case MTWEOF:
pt_write_fm(tape);
- return 0;
+ break;
default:
printk("%s: Unimplemented mt_op %d\n", tape->name,
mtop.mt_op);
- return -EINVAL;
+ err = -EINVAL;
}
+ break;
default:
printk("%s: Unimplemented ioctl 0x%x\n", tape->name, cmd);
- return -EINVAL;
-
+ err = -EINVAL;
+
}
+ unlock_kernel();
+ return err;
}
static int
-
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