1 files changed, 36 insertions, 23 deletions

diff --git a/fs/eventfd.c b/fs/eventfd.c
index e0194b3e14d..d6a88e7812f 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -16,9 +16,11 @@
 #include <linux/spinlock.h>
 #include <linux/anon_inodes.h>
 #include <linux/syscalls.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/kref.h>
 #include <linux/eventfd.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 
 struct eventfd_ctx {
 	struct kref kref;
@@ -46,20 +48,16 @@ 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);
@@ -99,7 +97,7 @@ EXPORT_SYMBOL_GPL(eventfd_ctx_get);
  * @ctx: [in] Pointer to eventfd context.
  *
  * The eventfd context reference must have been previously acquired either
- * with eventfd_ctx_get() or eventfd_ctx_fdget()).
+ * with eventfd_ctx_get() or eventfd_ctx_fdget().
  */
 void eventfd_ctx_put(struct eventfd_ctx *ctx)
 {
@@ -146,9 +144,9 @@ static void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt)
  * eventfd_ctx_remove_wait_queue - Read the current counter and removes wait queue.
  * @ctx: [in] Pointer to eventfd context.
  * @wait: [in] Wait queue to be removed.
- * @cnt: [out] Pointer to the 64bit conter value.
+ * @cnt: [out] Pointer to the 64-bit counter value.
  *
- * Returns zero if successful, or the following error codes:
+ * Returns %0 if successful, or the following error codes:
  *
  * -EAGAIN      : The operation would have blocked.
  *
@@ -175,11 +173,11 @@ 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 64bit conter value.
+ * @cnt: [out] Pointer to the 64-bit counter value.
  *
- * Returns zero if successful, or the following error codes:
+ * Returns %0 if successful, or the following error codes:
  *
- * -EAGAIN      : The operation would have blocked but @no_wait was nonzero.
+ * -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
@@ -288,7 +286,25 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c
 	return res;
 }
 
+#ifdef CONFIG_PROC_FS
+static int eventfd_show_fdinfo(struct seq_file *m, struct file *f)
+{
+	struct eventfd_ctx *ctx = f->private_data;
+	int ret;
+
+	spin_lock_irq(&ctx->wqh.lock);
+	ret = seq_printf(m, "eventfd-count: %16llx\n",
+			 (unsigned long long)ctx->count);
+	spin_unlock_irq(&ctx->wqh.lock);
+
+	return ret;
+}
+#endif
+
 static const struct file_operations eventfd_fops = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= eventfd_show_fdinfo,
+#endif
 	.release	= eventfd_release,
 	.poll		= eventfd_poll,
 	.read		= eventfd_read,
@@ -333,15 +349,12 @@ EXPORT_SYMBOL_GPL(eventfd_fget);
  */
 struct eventfd_ctx *eventfd_ctx_fdget(int fd)
 {
-	struct file *file;
 	struct eventfd_ctx *ctx;
-
-	file = eventfd_fget(fd);
-	if (IS_ERR(file))
-		return (struct eventfd_ctx *) file;
-	ctx = eventfd_ctx_get(file->private_data);
-	fput(file);
-
+	struct fd f = fdget(fd);
+	if (!f.file)
+		return ERR_PTR(-EBADF);
+	ctx = eventfd_ctx_fileget(f.file);
+	fdput(f);
 	return ctx;
 }
 EXPORT_SYMBOL_GPL(eventfd_ctx_fdget);