From 2b06ac867176d5d24757bda7e13f6255d6b96d7b Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 4 Feb 2008 16:47:59 +0100 Subject: [PATCH] x86: cpuid, msr: use inode mutex instead of big kernel lock Instead of grabbing the BKL on seek, use the inode mutex in the style of generic_file_llseek(). Signed-off-by: H. Peter Anvin Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpuid.c | 7 +++---- arch/x86/kernel/msr.c | 14 +++++++++----- 2 files changed, 12 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c index c10ebc4..288e7a6 100644 --- a/arch/x86/kernel/cpuid.c +++ b/arch/x86/kernel/cpuid.c @@ -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) { loff_t ret; + struct inode *inode = file->f_mapping->host; - lock_kernel(); - + mutex_lock(&inode->i_mutex); switch (orig) { case 0: file->f_pos = offset; @@ -77,8 +77,7 @@ static loff_t cpuid_seek(struct file *file, loff_t offset, int orig) default: ret = -EINVAL; } - - unlock_kernel(); + mutex_unlock(&inode->i_mutex); return ret; } diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index bd82850..af51ea8 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -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 * 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) { - loff_t ret = -EINVAL; + loff_t ret; + struct inode *inode = file->f_mapping->host; - lock_kernel(); + mutex_lock(&inode->i_mutex); switch (orig) { case 0: file->f_pos = offset; @@ -56,8 +57,11 @@ static loff_t msr_seek(struct file *file, loff_t offset, int orig) case 1: file->f_pos += offset; ret = file->f_pos; + break; + default: + ret = -EINVAL; } - unlock_kernel(); + mutex_unlock(&inode->i_mutex); return ret; } -- 1.8.2.3