Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH 11/12] ipmi: autoconvert trivial BKL users to private mutex | Date | Sun, 11 Jul 2010 23:19:02 +0200 |
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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> Cc: Corey Minyard <minyard@acm.org> Cc: openipmi-developer@lists.sourceforge.net --- drivers/char/ipmi/ipmi_devintf.c | 14 +++++++------- drivers/char/ipmi/ipmi_watchdog.c | 8 ++++---- 2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/char/ipmi/ipmi_devintf.c b/drivers/char/ipmi/ipmi_devintf.c index d8ec92a..44833de 100644 --- a/drivers/char/ipmi/ipmi_devintf.c +++ b/drivers/char/ipmi/ipmi_devintf.c @@ -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; } diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c index 82bcdb2..d80b8c9 100644 --- a/drivers/char/ipmi/ipmi_watchdog.c +++ b/drivers/char/ipmi/ipmi_watchdog.c @@ -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; @@ -736,9 +737,9 @@ 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; } @@ -832,7 +833,6 @@ 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 -- 1.7.1
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