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authorArnd Bergmann <arnd@arndb.de>2010-09-11 18:38:03 +0200
committerArnd Bergmann <arnd@arndb.de>2010-10-19 11:29:42 +0200
commit9a181c58617134822ae596339dbea076ef9b5cf7 (patch)
treeb90b52c0bcb4ae3057e5ddd403230415f4cb528a /arch/um/drivers
parentfa0d4c26be9f989816b30626f6c67d9e7ef867f8 (diff)
downloadlinux-9a181c58617134822ae596339dbea076ef9b5cf7.tar.bz2
uml: kill big kernel lock
Three uml device drivers still use the big kernel lock, but all of them can be safely converted to using a per-driver mutex instead. Most likely this is not even necessary, so after further review these can and should be removed as well. The exec system call no longer requires the BKL either, so remove it from there, too. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: user-mode-linux-devel@lists.sourceforge.net
Diffstat (limited to 'arch/um/drivers')
-rw-r--r--arch/um/drivers/harddog_kern.c13
-rw-r--r--arch/um/drivers/hostaudio_kern.c12
-rw-r--r--arch/um/drivers/ubd_kern.c11
3 files changed, 20 insertions, 16 deletions
diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index cfcac1ff4cf2..86036276020f 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -42,7 +42,7 @@
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
@@ -50,6 +50,7 @@
MODULE_LICENSE("GPL");
+static DEFINE_MUTEX(harddog_mutex);
static DEFINE_SPINLOCK(lock);
static int timer_alive;
static int harddog_in_fd = -1;
@@ -66,7 +67,7 @@ static int harddog_open(struct inode *inode, struct file *file)
int err = -EBUSY;
char *sock = NULL;
- lock_kernel();
+ mutex_lock(&harddog_mutex);
spin_lock(&lock);
if(timer_alive)
goto err;
@@ -83,11 +84,11 @@ static int harddog_open(struct inode *inode, struct file *file)
timer_alive = 1;
spin_unlock(&lock);
- unlock_kernel();
+ mutex_unlock(&harddog_mutex);
return nonseekable_open(inode, file);
err:
spin_unlock(&lock);
- unlock_kernel();
+ mutex_unlock(&harddog_mutex);
return err;
}
@@ -153,9 +154,9 @@ static long harddog_ioctl(struct file *file,
{
long ret;
- lock_kernel();
+ mutex_lock(&harddog_mutex);
ret = harddog_ioctl_unlocked(file, cmd, arg);
- unlock_kernel();
+ mutex_unlock(&harddog_mutex);
return ret;
}
diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
index 0c46e398cd8f..d92ff6d60297 100644
--- a/arch/um/drivers/hostaudio_kern.c
+++ b/arch/um/drivers/hostaudio_kern.c
@@ -8,7 +8,7 @@
#include "linux/slab.h"
#include "linux/sound.h"
#include "linux/soundcard.h"
-#include "linux/smp_lock.h"
+#include "linux/mutex.h"
#include "asm/uaccess.h"
#include "init.h"
#include "os.h"
@@ -67,6 +67,8 @@ MODULE_PARM_DESC(mixer, MIXER_HELP);
#endif
+static DEFINE_MUTEX(hostaudio_mutex);
+
/* /dev/dsp file operations */
static ssize_t hostaudio_read(struct file *file, char __user *buffer,
@@ -202,9 +204,9 @@ static int hostaudio_open(struct inode *inode, struct file *file)
w = 1;
kparam_block_sysfs_write(dsp);
- lock_kernel();
+ mutex_lock(&hostaudio_mutex);
ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
- unlock_kernel();
+ mutex_unlock(&hostaudio_mutex);
kparam_unblock_sysfs_write(dsp);
if (ret < 0) {
@@ -263,9 +265,9 @@ static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
w = 1;
kparam_block_sysfs_write(mixer);
- lock_kernel();
+ mutex_lock(&hostaudio_mutex);
ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
- unlock_kernel();
+ mutex_unlock(&hostaudio_mutex);
kparam_unblock_sysfs_write(mixer);
if (ret < 0) {
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 1bcd208c459f..0c053607ce98 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -33,7 +33,7 @@
#include "linux/mm.h"
#include "linux/slab.h"
#include "linux/vmalloc.h"
-#include "linux/smp_lock.h"
+#include "linux/mutex.h"
#include "linux/blkpg.h"
#include "linux/genhd.h"
#include "linux/spinlock.h"
@@ -100,6 +100,7 @@ static inline void ubd_set_bit(__u64 bit, unsigned char *data)
#define DRIVER_NAME "uml-blkdev"
static DEFINE_MUTEX(ubd_lock);
+static DEFINE_MUTEX(ubd_mutex); /* replaces BKL, might not be needed */
static int ubd_open(struct block_device *bdev, fmode_t mode);
static int ubd_release(struct gendisk *disk, fmode_t mode);
@@ -1099,7 +1100,7 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
struct ubd *ubd_dev = disk->private_data;
int err = 0;
- lock_kernel();
+ mutex_lock(&ubd_mutex);
if(ubd_dev->count == 0){
err = ubd_open_dev(ubd_dev);
if(err){
@@ -1118,7 +1119,7 @@ static int ubd_open(struct block_device *bdev, fmode_t mode)
err = -EROFS;
}*/
out:
- unlock_kernel();
+ mutex_unlock(&ubd_mutex);
return err;
}
@@ -1126,10 +1127,10 @@ static int ubd_release(struct gendisk *disk, fmode_t mode)
{
struct ubd *ubd_dev = disk->private_data;
- lock_kernel();
+ mutex_lock(&ubd_mutex);
if(--ubd_dev->count == 0)
ubd_close_dev(ubd_dev);
- unlock_kernel();
+ mutex_unlock(&ubd_mutex);
return 0;
}