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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
parentfa0d4c26be9f989816b30626f6c67d9e7ef867f8 (diff)
downloadop-kernel-dev-9a181c58617134822ae596339dbea076ef9b5cf7.zip
op-kernel-dev-9a181c58617134822ae596339dbea076ef9b5cf7.tar.gz
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
-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
-rw-r--r--arch/um/kernel/exec.c2
4 files changed, 20 insertions, 18 deletions
diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index cfcac1f..8603627 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 0c46e39..d92ff6d 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 1bcd208..0c05360 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;
}
diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index cd145ed..460ce86 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -78,13 +78,11 @@ long sys_execve(const char __user *file, char __user *__user *argv,
long error;
char *filename;
- lock_kernel();
filename = getname(file);
error = PTR_ERR(filename);
if (IS_ERR(filename)) goto out;
error = execve1(filename, argv, env);
putname(filename);
out:
- unlock_kernel();
return error;
}
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