diff options
| -rw-r--r-- | include/linux/posix-clock.h | 5 | ||||
| -rw-r--r-- | kernel/time/posix-clock.c | 24 |
2 files changed, 12 insertions, 17 deletions
diff --git a/include/linux/posix-clock.h b/include/linux/posix-clock.h index 369e19d3750..7f1183dcd11 100644 --- a/include/linux/posix-clock.h +++ b/include/linux/posix-clock.h @@ -24,6 +24,7 @@ #include <linux/fs.h> #include <linux/poll.h> #include <linux/posix-timers.h> +#include <linux/rwsem.h> struct posix_clock; @@ -104,7 +105,7 @@ struct posix_clock_operations { * @ops: Functional interface to the clock * @cdev: Character device instance for this clock * @kref: Reference count. - * @mutex: Protects the 'zombie' field from concurrent access. + * @rwsem: Protects the 'zombie' field from concurrent access. * @zombie: If 'zombie' is true, then the hardware has disappeared. * @release: A function to free the structure when the reference count reaches * zero. May be NULL if structure is statically allocated. @@ -117,7 +118,7 @@ struct posix_clock { struct posix_clock_operations ops; struct cdev cdev; struct kref kref; - struct mutex mutex; + struct rw_semaphore rwsem; bool zombie; void (*release)(struct posix_clock *clk); }; diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c index 25028dd4fa1..c340ca658f3 100644 --- a/kernel/time/posix-clock.c +++ b/kernel/time/posix-clock.c @@ -19,7 +19,6 @@ */ #include <linux/device.h> #include <linux/file.h> -#include <linux/mutex.h> #include <linux/posix-clock.h> #include <linux/slab.h> #include <linux/syscalls.h> @@ -34,19 +33,19 @@ static struct posix_clock *get_posix_clock(struct file *fp) { struct posix_clock *clk = fp->private_data; - mutex_lock(&clk->mutex); + down_read(&clk->rwsem); if (!clk->zombie) return clk; - mutex_unlock(&clk->mutex); + up_read(&clk->rwsem); return NULL; } static void put_posix_clock(struct posix_clock *clk) { - mutex_unlock(&clk->mutex); + up_read(&clk->rwsem); } static ssize_t posix_clock_read(struct file *fp, char __user *buf, @@ -156,7 +155,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp) struct posix_clock *clk = container_of(inode->i_cdev, struct posix_clock, cdev); - mutex_lock(&clk->mutex); + down_read(&clk->rwsem); if (clk->zombie) { err = -ENODEV; @@ -172,7 +171,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp) fp->private_data = clk; } out: - mutex_unlock(&clk->mutex); + up_read(&clk->rwsem); return err; } @@ -211,25 +210,20 @@ int posix_clock_register(struct posix_clock *clk, dev_t devid) int err; kref_init(&clk->kref); - mutex_init(&clk->mutex); + init_rwsem(&clk->rwsem); cdev_init(&clk->cdev, &posix_clock_file_operations); clk->cdev.owner = clk->ops.owner; err = cdev_add(&clk->cdev, devid, 1); - if (err) - goto no_cdev; return err; -no_cdev: - mutex_destroy(&clk->mutex); - return err; } EXPORT_SYMBOL_GPL(posix_clock_register); static void delete_clock(struct kref *kref) { struct posix_clock *clk = container_of(kref, struct posix_clock, kref); - mutex_destroy(&clk->mutex); + if (clk->release) clk->release(clk); } @@ -238,9 +232,9 @@ void posix_clock_unregister(struct posix_clock *clk) { cdev_del(&clk->cdev); - mutex_lock(&clk->mutex); + down_write(&clk->rwsem); clk->zombie = true; - mutex_unlock(&clk->mutex); + up_write(&clk->rwsem); kref_put(&clk->kref, delete_clock); } |