Commit b7638ad0 authored by Christian Brauner's avatar Christian Brauner
Browse files

eventfd: make eventfd_signal{_mask}() void 

No caller care about the return value.

Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-4-bd549b14ce0c@kernel.org


Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 120ae585

fs/eventfd.c

+15 −25
Original line number Diff line number Diff line
@@ -43,10 +43,19 @@ struct eventfd_ctx { 
	int id;

};



__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)

/**

 * eventfd_signal_mask - Increment the event counter

 * @ctx: [in] Pointer to the eventfd context.

 * @mask: [in] poll mask

 *

 * This function is supposed to be called by the kernel in paths that do not

 * allow sleeping. In this function we allow the counter to reach the ULLONG_MAX

 * value, and we signal this as overflow condition by returning a EPOLLERR

 * to poll(2).

 */

void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)

{

	unsigned long flags;

	__u64 n = 1;



	/*

	 * Deadlock or stack overflow issues can happen if we recurse here
@@ -57,37 +66,18 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask) 
	 * safe context.

	 */

	if (WARN_ON_ONCE(current->in_eventfd))

		return 0;

		return;



	spin_lock_irqsave(&ctx->wqh.lock, flags);

	current->in_eventfd = 1;

	if (ULLONG_MAX - ctx->count < n)

		n = ULLONG_MAX - ctx->count;

	ctx->count += n;

	if (ctx->count < ULLONG_MAX)

		ctx->count++;

	if (waitqueue_active(&ctx->wqh))

		wake_up_locked_poll(&ctx->wqh, EPOLLIN | mask);

	current->in_eventfd = 0;

	spin_unlock_irqrestore(&ctx->wqh.lock, flags);



	return n == 1;

}



/**

 * eventfd_signal - Increment the event counter

 * @ctx: [in] Pointer to the eventfd context.

 *

 * This function is supposed to be called by the kernel in paths that do not

 * allow sleeping. In this function we allow the counter to reach the ULLONG_MAX

 * value, and we signal this as overflow condition by returning a EPOLLERR

 * to poll(2).

 *

 * Returns the amount by which the counter was incremented.

 */

__u64 eventfd_signal(struct eventfd_ctx *ctx)

{

	return eventfd_signal_mask(ctx, 0);

}

EXPORT_SYMBOL_GPL(eventfd_signal);

EXPORT_SYMBOL_GPL(eventfd_signal_mask);



static void eventfd_free_ctx(struct eventfd_ctx *ctx)

{

include/linux/eventfd.h

+7 −9
Original line number Diff line number Diff line
@@ -35,8 +35,7 @@ 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);

__u64 eventfd_signal(struct eventfd_ctx *ctx);

__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);

void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);

int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,

				  __u64 *cnt);

void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
@@ -58,14 +57,8 @@ static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd) 
	return ERR_PTR(-ENOSYS);

}



static inline int eventfd_signal(struct eventfd_ctx *ctx)

static inline void eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)

{

	return -ENOSYS;

}



static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)

{

	return -ENOSYS;

}



static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
@@ -91,5 +84,10 @@ static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt) 


#endif



static inline void eventfd_signal(struct eventfd_ctx *ctx)

{

	eventfd_signal_mask(ctx, 0);

}



#endif /* _LINUX_EVENTFD_H */