diff options
| -rw-r--r-- | fs/eventfd.c | 53 | ||||
| -rw-r--r-- | include/linux/eventfd.h | 7 |
2 files changed, 15 insertions, 45 deletions
diff --git a/fs/eventfd.c b/fs/eventfd.c index 4167e670ed4d..6138d2b5cdeb 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -207,36 +207,27 @@ int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *w } EXPORT_SYMBOL_GPL(eventfd_ctx_remove_wait_queue); -/** - * eventfd_ctx_read - Reads the eventfd counter or wait if it is zero. - * @ctx: [in] Pointer to eventfd context. - * @no_wait: [in] Different from zero if the operation should not block. - * @cnt: [out] Pointer to the 64-bit counter value. - * - * Returns %0 if successful, or the following error codes: - * - * - -EAGAIN : The operation would have blocked but @no_wait was non-zero. - * - -ERESTARTSYS : A signal interrupted the wait operation. - * - * If @no_wait is zero, the function might sleep until the eventfd internal - * counter becomes greater than zero. - */ -ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt) +static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count, + loff_t *ppos) { + struct eventfd_ctx *ctx = file->private_data; ssize_t res; + __u64 ucnt = 0; DECLARE_WAITQUEUE(wait, current); + if (count < sizeof(ucnt)) + return -EINVAL; + spin_lock_irq(&ctx->wqh.lock); - *cnt = 0; res = -EAGAIN; if (ctx->count > 0) - res = 0; - else if (!no_wait) { + res = sizeof(ucnt); + else if (!(file->f_flags & O_NONBLOCK)) { __add_wait_queue(&ctx->wqh, &wait); for (;;) { set_current_state(TASK_INTERRUPTIBLE); if (ctx->count > 0) { - res = 0; + res = sizeof(ucnt); break; } if (signal_pending(current)) { @@ -250,31 +241,17 @@ ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt) __remove_wait_queue(&ctx->wqh, &wait); __set_current_state(TASK_RUNNING); } - if (likely(res == 0)) { - eventfd_ctx_do_read(ctx, cnt); + if (likely(res > 0)) { + eventfd_ctx_do_read(ctx, &ucnt); if (waitqueue_active(&ctx->wqh)) wake_up_locked_poll(&ctx->wqh, POLLOUT); } spin_unlock_irq(&ctx->wqh.lock); - return res; -} -EXPORT_SYMBOL_GPL(eventfd_ctx_read); - -static ssize_t eventfd_read(struct file *file, char __user *buf, size_t count, - loff_t *ppos) -{ - struct eventfd_ctx *ctx = file->private_data; - ssize_t res; - __u64 cnt; - - if (count < sizeof(cnt)) - return -EINVAL; - res = eventfd_ctx_read(ctx, file->f_flags & O_NONBLOCK, &cnt); - if (res < 0) - return res; + if (res > 0 && put_user(ucnt, (__u64 __user *)buf)) + return -EFAULT; - return put_user(cnt, (__u64 __user *) buf) ? -EFAULT : sizeof(cnt); + return res; } static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t count, diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index 15826192cc23..566fef14d0a6 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -36,7 +36,6 @@ struct file *eventfd_fget(int fd); struct eventfd_ctx *eventfd_ctx_fdget(int fd); struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n); -ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt); int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, __u64 *cnt); @@ -62,12 +61,6 @@ static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) } -static inline ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, - __u64 *cnt) -{ - return -ENOSYS; -} - static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, __u64 *cnt) { |