[patch 11/28] nvram: Drop the bkl from nvram_llseek()

From: Thomas Gleixner
Date: Sat Oct 10 2009 - 11:38:49 EST


There is nothing to protect inside nvram_llseek(), the file
offset doesn't need to be protected and nvram_len is only
initialized from an __init path.

It's safe to remove the big kernel lock there.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: John Kacur <jkacur@xxxxxxxxxx>
Cc: Sven-Thorsten Dietrich <sven@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Alessio Igor Bogani <abogani@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxx>
LKML-Reference: <1255116030-6929-1-git-send-email-fweisbec@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
drivers/char/generic_nvram.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

Index: linux-2.6-tip/drivers/char/generic_nvram.c
===================================================================
--- linux-2.6-tip.orig/drivers/char/generic_nvram.c
+++ linux-2.6-tip/drivers/char/generic_nvram.c
@@ -19,7 +19,6 @@
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/init.h>
-#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>
#ifdef CONFIG_PPC_PMAC
@@ -32,7 +31,6 @@ static ssize_t nvram_len;

static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
{
- lock_kernel();
switch (origin) {
case 1:
offset += file->f_pos;
@@ -41,12 +39,11 @@ static loff_t nvram_llseek(struct file *
offset += nvram_len;
break;
}
- if (offset < 0) {
- unlock_kernel();
+ if (offset < 0)
return -EINVAL;
- }
+
file->f_pos = offset;
- unlock_kernel();
+
return file->f_pos;
}



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