sony_pi: Remove the BKL from open and ioctl
John Kacur [Sun, 18 Oct 2009 21:49:49 +0000 (23:49 +0200)]
The BKL is in this function because of the BKL pushdown (see commit
f8f2c79d594463427f7114cedb1555110d547d89)

It is not needed here because the mutex_lock sonypi_device.lock provides
the necessary locking.

sonypi_misc_ioctl can be converted to unlocked ioctls since it relies on
its own locking (the mutex sonypi_device.lock) and not the bkl

Document that llseek is not needed by explictly setting it to no_llseek

LKML-Reference: <alpine.LFD.2.00.0910192019420.3563@localhost.localdomain>
Signed-off-by: John Kacur <jkacur@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/sonypi.c

index 0798754..bba727c 100644 (file)
@@ -50,7 +50,6 @@
 #include <linux/err.h>
 #include <linux/kfifo.h>
 #include <linux/platform_device.h>
-#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -905,14 +904,13 @@ static int sonypi_misc_release(struct inode *inode, struct file *file)
 
 static int sonypi_misc_open(struct inode *inode, struct file *file)
 {
-       lock_kernel();
        mutex_lock(&sonypi_device.lock);
        /* Flush input queue on first open */
        if (!sonypi_device.open_count)
                kfifo_reset(&sonypi_device.fifo);
        sonypi_device.open_count++;
        mutex_unlock(&sonypi_device.lock);
-       unlock_kernel();
+
        return 0;
 }
 
@@ -955,10 +953,10 @@ static unsigned int sonypi_misc_poll(struct file *file, poll_table *wait)
        return 0;
 }
 
-static int sonypi_misc_ioctl(struct inode *ip, struct file *fp,
+static long sonypi_misc_ioctl(struct file *fp,
                             unsigned int cmd, unsigned long arg)
 {
-       int ret = 0;
+       long ret = 0;
        void __user *argp = (void __user *)arg;
        u8 val8;
        u16 val16;
@@ -1074,7 +1072,8 @@ static const struct file_operations sonypi_misc_fops = {
        .open           = sonypi_misc_open,
        .release        = sonypi_misc_release,
        .fasync         = sonypi_misc_fasync,
-       .ioctl          = sonypi_misc_ioctl,
+       .unlocked_ioctl = sonypi_misc_ioctl,
+       .llseek         = no_llseek,
 };
 
 static struct miscdevice sonypi_misc_device = {