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authorArnd Bergmann <arnd@arndb.de>2010-06-02 16:28:52 +0400
committerArnd Bergmann <arnd@arndb.de>2010-10-05 17:01:04 +0400
commit613655fa39ff6957754fa8ceb8559980920eb8ee (patch)
treead19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/lp.c
parent609146fdb319cebce93be550938ab852f7bade90 (diff)
downloadlinux-613655fa39ff6957754fa8ceb8559980920eb8ee.tar.xz
drivers: autoconvert trivial BKL users to private mutex
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. These drivers do not seem to be under active maintainance from my brief investigation. Apologies to those maintainers that I have missed. 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>
Diffstat (limited to 'drivers/char/lp.c')
-rw-r--r--drivers/char/lp.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 938a3a273886..598d278db058 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -126,7 +126,7 @@
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/jiffies.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/compat.h>
#include <linux/parport.h>
@@ -140,6 +140,7 @@
/* if you have more than 8 printers, remember to increase LP_NO */
#define LP_NO 8
+static DEFINE_MUTEX(lp_mutex);
static struct lp_struct lp_table[LP_NO];
static unsigned int lp_count = 0;
@@ -493,7 +494,7 @@ static int lp_open(struct inode * inode, struct file * file)
unsigned int minor = iminor(inode);
int ret = 0;
- lock_kernel();
+ mutex_lock(&lp_mutex);
if (minor >= LP_NO) {
ret = -ENXIO;
goto out;
@@ -554,7 +555,7 @@ static int lp_open(struct inode * inode, struct file * file)
lp_release_parport (&lp_table[minor]);
lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
out:
- unlock_kernel();
+ mutex_unlock(&lp_mutex);
return ret;
}
@@ -680,7 +681,7 @@ static long lp_ioctl(struct file *file, unsigned int cmd,
int ret;
minor = iminor(file->f_path.dentry->d_inode);
- lock_kernel();
+ mutex_lock(&lp_mutex);
switch (cmd) {
case LPSETTIMEOUT:
if (copy_from_user(&par_timeout, (void __user *)arg,
@@ -694,7 +695,7 @@ static long lp_ioctl(struct file *file, unsigned int cmd,
ret = lp_do_ioctl(minor, cmd, arg, (void __user *)arg);
break;
}
- unlock_kernel();
+ mutex_unlock(&lp_mutex);
return ret;
}
@@ -709,7 +710,7 @@ static long lp_compat_ioctl(struct file *file, unsigned int cmd,
int ret;
minor = iminor(file->f_path.dentry->d_inode);
- lock_kernel();
+ mutex_lock(&lp_mutex);
switch (cmd) {
case LPSETTIMEOUT:
tc = compat_ptr(arg);
@@ -730,7 +731,7 @@ static long lp_compat_ioctl(struct file *file, unsigned int cmd,
ret = lp_do_ioctl(minor, cmd, arg, compat_ptr(arg));
break;
}
- unlock_kernel();
+ mutex_unlock(&lp_mutex);
return ret;
}