From 9a181c58617134822ae596339dbea076ef9b5cf7 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sat, 11 Sep 2010 18:38:03 +0200 Subject: [PATCH] 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 Cc: Jeff Dike Cc: user-mode-linux-devel@lists.sourceforge.net --- arch/um/drivers/harddog_kern.c | 13 +++++++------ arch/um/drivers/hostaudio_kern.c | 12 +++++++----- arch/um/drivers/ubd_kern.c | 11 ++++++----- arch/um/kernel/exec.c | 2 -- 4 files changed, 20 insertions(+), 18 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 #include #include -#include +#include #include #include #include @@ -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; } diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c index cd145eda3579..460ce86f4019 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; }