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x86: cpuid, msr: use inode mutex instead of big kernel lock

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Instead of grabbing the BKL on seek, use the inode mutex in the style
of generic_file_llseek().

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
H. Peter Anvin 2008-02-04 16:47:59 +01:00 committed by Ingo Molnar
parent 2347d933b1
commit 2b06ac8671
2 changed files with 12 additions and 9 deletions
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7
arch/x86/kernel/cpuid.c
View File

@ -62,9 +62,9 @@ static void cpuid_smp_cpuid(void *cmd_block)
static loff_t cpuid_seek(struct file *file, loff_t offset, int orig) static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
{ {
loff_t ret; loff_t ret;
struct inode *inode = file->f_mapping->host;
lock_kernel(); mutex_lock(&inode->i_mutex);
switch (orig) { switch (orig) {
case 0: case 0:
file->f_pos = offset; file->f_pos = offset;
@ -77,8 +77,7 @@ static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
default: default:
ret = -EINVAL; ret = -EINVAL;
} }
mutex_unlock(&inode->i_mutex);
unlock_kernel();
return ret; return ret;
} }

14
arch/x86/kernel/msr.c
View File

@ -1,6 +1,6 @@
/* ----------------------------------------------------------------------- * /* ----------------------------------------------------------------------- *
* *
* Copyright 2000 H. Peter Anvin - All Rights Reserved * Copyright 2000-2008 H. Peter Anvin - All Rights Reserved
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by * it under the terms of the GNU General Public License as published by
@ -45,9 +45,10 @@ static struct class *msr_class;
static loff_t msr_seek(struct file *file, loff_t offset, int orig) static loff_t msr_seek(struct file *file, loff_t offset, int orig)
{ {
loff_t ret = -EINVAL; loff_t ret;
struct inode *inode = file->f_mapping->host;
lock_kernel(); mutex_lock(&inode->i_mutex);
switch (orig) { switch (orig) {
case 0: case 0:
file->f_pos = offset; file->f_pos = offset;
@ -56,8 +57,11 @@ static loff_t msr_seek(struct file *file, loff_t offset, int orig)
case 1: case 1:
file->f_pos += offset; file->f_pos += offset;
ret = file->f_pos; ret = file->f_pos;
break;
default:
ret = -EINVAL;
} }
unlock_kernel(); mutex_unlock(&inode->i_mutex);
return ret; return ret;
} }