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authorArnd Bergmann <arnd@arndb.de>2010-06-02 08:28:52 -0400
committerArnd Bergmann <arnd@arndb.de>2010-10-05 09:01:04 -0400
commit613655fa39ff6957754fa8ceb8559980920eb8ee (patch)
treead19600cb81207b24188683d7fc4ae88013339d1 /drivers/char/dtlk.c
parent609146fdb319cebce93be550938ab852f7bade90 (diff)
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/dtlk.c')
-rw-r--r--drivers/char/dtlk.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c
index e3859d4eaead..8dd040a945d4 100644
--- a/drivers/char/dtlk.c
+++ b/drivers/char/dtlk.c
@@ -57,7 +57,7 @@
57#include <linux/ioport.h> /* for request_region */ 57#include <linux/ioport.h> /* for request_region */
58#include <linux/delay.h> /* for loops_per_jiffy */ 58#include <linux/delay.h> /* for loops_per_jiffy */
59#include <linux/sched.h> 59#include <linux/sched.h>
60#include <linux/smp_lock.h> /* cycle_kernel_lock() */ 60#include <linux/mutex.h>
61#include <asm/io.h> /* for inb_p, outb_p, inb, outb, etc. */ 61#include <asm/io.h> /* for inb_p, outb_p, inb, outb, etc. */
62#include <asm/uaccess.h> /* for get_user, etc. */ 62#include <asm/uaccess.h> /* for get_user, etc. */
63#include <linux/wait.h> /* for wait_queue */ 63#include <linux/wait.h> /* for wait_queue */
@@ -73,6 +73,7 @@
73#define TRACE_RET ((void) 0) 73#define TRACE_RET ((void) 0)
74#endif /* TRACING */ 74#endif /* TRACING */
75 75
76static DEFINE_MUTEX(dtlk_mutex);
76static void dtlk_timer_tick(unsigned long data); 77static void dtlk_timer_tick(unsigned long data);
77 78
78static int dtlk_major; 79static int dtlk_major;
@@ -275,9 +276,9 @@ static long dtlk_ioctl(struct file *file,
275 switch (cmd) { 276 switch (cmd) {
276 277
277 case DTLK_INTERROGATE: 278 case DTLK_INTERROGATE:
278 lock_kernel(); 279 mutex_lock(&dtlk_mutex);
279 sp = dtlk_interrogate(); 280 sp = dtlk_interrogate();
280 unlock_kernel(); 281 mutex_unlock(&dtlk_mutex);
281 if (copy_to_user(argp, sp, sizeof(struct dtlk_settings))) 282 if (copy_to_user(argp, sp, sizeof(struct dtlk_settings)))
282 return -EINVAL; 283 return -EINVAL;
283 return 0; 284 return 0;
@@ -296,7 +297,6 @@ static int dtlk_open(struct inode *inode, struct file *file)
296{ 297{
297 TRACE_TEXT("(dtlk_open"); 298 TRACE_TEXT("(dtlk_open");
298 299
299 cycle_kernel_lock();
300 nonseekable_open(inode, file); 300 nonseekable_open(inode, file);
301 switch (iminor(inode)) { 301 switch (iminor(inode)) {
302 case DTLK_MINOR: 302 case DTLK_MINOR: