diff options
| author | Sha Zhengju <handai.szj@taobao.com> | 2012-05-31 16:26:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-31 17:49:32 -0700 |
| commit | ee62c6b2dc93c09585b51fad18449dc5edb9977f (patch) | |
| tree | 538f5338f6a00d1a4cee9e69ba74082747a452aa | |
| parent | 71ca97da9d027009d318d319cbacf54a72f666c1 (diff) | |
| download | linux-ee62c6b2dc93c09585b51fad18449dc5edb9977f.tar.bz2 | |
eventfd: change int to __u64 in eventfd_signal()
eventfd_ctx->count is an __u64 counter which is allowed to reach
ULLONG_MAX. eventfd_write() adds a __u64 value to "count", but the kernel
side eventfd_signal() only adds an int value to it. Make them consistent.
[akpm@linux-foundation.org: update interface documentation]
Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/eventfd.c | 12 | ||||
| -rw-r--r-- | include/linux/eventfd.h | 2 |
2 files changed, 5 insertions, 9 deletions
diff --git a/fs/eventfd.c b/fs/eventfd.c index dba15fecf23e..d81b9f654086 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -46,20 +46,16 @@ struct eventfd_ctx { * value, and we signal this as overflow condition by returining a POLLERR * to poll(2). * - * Returns @n in case of success, a non-negative number lower than @n in case - * of overflow, or the following error codes: - * - * -EINVAL : The value of @n is negative. + * Returns the amount by which the counter was incrememnted. This will be less + * than @n if the counter has overflowed. */ -int eventfd_signal(struct eventfd_ctx *ctx, int n) +__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n) { unsigned long flags; - if (n < 0) - return -EINVAL; spin_lock_irqsave(&ctx->wqh.lock, flags); if (ULLONG_MAX - ctx->count < n) - n = (int) (ULLONG_MAX - ctx->count); + n = ULLONG_MAX - ctx->count; ctx->count += n; if (waitqueue_active(&ctx->wqh)) wake_up_locked_poll(&ctx->wqh, POLLIN); diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index 91bb4f27238c..3c3ef19a625a 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -34,7 +34,7 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx); struct file *eventfd_fget(int fd); struct eventfd_ctx *eventfd_ctx_fdget(int fd); struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); -int eventfd_signal(struct eventfd_ctx *ctx, int n); +__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_t *wait, __u64 *cnt); |