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ipmi: autoconvert trivial BKL users to private mutex

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All these files use the big kernel lock in a trivial
way to serialize their private file operations,
typically resulting from an earlier semi-automatic
pushdown from VFS.

None of these drivers appears to want to lock against
other code, and they all use the BKL as the top-level
lock in their file operations, meaning that there
is no lock-order inversion problem.

Consequently, we can remove the BKL completely,
replacing it with a per-file mutex in every case.
Using a scripted approach means we can avoid
typos.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Corey Minyard <cminyard@mvista.com>
Cc: openipmi-developer@lists.sourceforge.net
This commit is contained in:
Arnd Bergmann
2010-06-02 14:28:52 +02:00
parent d851b6e04e
commit 609146fdb3
2 changed files with 11 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/char/ipmi/ipmi_devintf.c
View File

@@ -44,7 +44,6 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
struct ipmi_file_private
{
@@ -59,6 +58,7 @@ struct ipmi_file_private
unsigned int default_retry_time_ms;
};
static DEFINE_MUTEX(ipmi_mutex);
static void file_receive_handler(struct ipmi_recv_msg *msg,
void *handler_data)
{
@@ -102,9 +102,9 @@ static int ipmi_fasync(int fd, struct file *file, int on)
struct ipmi_file_private *priv = file->private_data;
int result;
lock_kernel(); /* could race against open() otherwise */
mutex_lock(&ipmi_mutex); /* could race against open() otherwise */
result = fasync_helper(fd, file, on, &priv->fasync_queue);
unlock_kernel();
mutex_unlock(&ipmi_mutex);
return (result);
}
@@ -125,7 +125,7 @@ static int ipmi_open(struct inode *inode, struct file *file)
if (!priv)
return -ENOMEM;
lock_kernel();
mutex_lock(&ipmi_mutex);
priv->file = file;
rv = ipmi_create_user(if_num,
@@ -150,7 +150,7 @@ static int ipmi_open(struct inode *inode, struct file *file)
priv->default_retry_time_ms = 0;
out:
unlock_kernel();
mutex_unlock(&ipmi_mutex);
return rv;
}
@@ -639,9 +639,9 @@ static long ipmi_unlocked_ioctl(struct file *file,
{
int ret;
lock_kernel();
mutex_lock(&ipmi_mutex);
ret = ipmi_ioctl(file, cmd, data);
unlock_kernel();
mutex_unlock(&ipmi_mutex);
return ret;
}

8
drivers/char/ipmi/ipmi_watchdog.c
View File

@@ -35,7 +35,7 @@
#include <linux/moduleparam.h>
#include <linux/ipmi.h>
#include <linux/ipmi_smi.h>
#include <linux/smp_lock.h>
#include <linux/mutex.h>
#include <linux/watchdog.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
@@ -149,6 +149,7 @@
#define WDIOC_GET_PRETIMEOUT _IOW(WATCHDOG_IOCTL_BASE, 22, int)
#endif
static DEFINE_MUTEX(ipmi_watchdog_mutex);
static int nowayout = WATCHDOG_NOWAYOUT;
static ipmi_user_t watchdog_user;
@@ -748,9 +749,9 @@ static long ipmi_unlocked_ioctl(struct file *file,
{
int ret;
lock_kernel();
mutex_lock(&ipmi_watchdog_mutex);
ret = ipmi_ioctl(file, cmd, arg);
unlock_kernel();
mutex_unlock(&ipmi_watchdog_mutex);
return ret;
}
@@ -844,7 +845,6 @@ static int ipmi_open(struct inode *ino, struct file *filep)
if (test_and_set_bit(0, &ipmi_wdog_open))
return -EBUSY;
cycle_kernel_lock();
/*
* Don't start the timer now, let it start on the