linux-stable/include/linux/eventfd.h
Wen Yang 2d8c9dcf71 eventfd: add a uapi header for eventfd userspace APIs
Create a uapi header include/uapi/linux/eventfd.h, move the associated
flags to the uapi header, and include it from linux/eventfd.h.

Suggested-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Eric Biggers <ebiggers@google.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Message-Id: <tencent_2B6A999A23E86E522D5D9859D54FFCF9AA05@qq.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-15 14:55:15 +02:00

96 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* include/linux/eventfd.h
*
* Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
*
*/
#ifndef _LINUX_EVENTFD_H
#define _LINUX_EVENTFD_H
#include <linux/wait.h>
#include <linux/err.h>
#include <linux/percpu-defs.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <uapi/linux/eventfd.h>
/*
* CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
* new flags, since they might collide with O_* ones. We want
* to re-use O_* flags that couldn't possibly have a meaning
* from eventfd, in order to leave a free define-space for
* shared O_* flags.
*/
#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE)
struct eventfd_ctx;
struct file;
#ifdef CONFIG_EVENTFD
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 n);
__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __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);
static inline bool eventfd_signal_allowed(void)
{
return !current->in_eventfd;
}
#else /* CONFIG_EVENTFD */
/*
* Ugly ugly ugly error layer to support modules that uses eventfd but
* pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO.
*/
static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
{
return ERR_PTR(-ENOSYS);
}
static inline int eventfd_signal(struct eventfd_ctx *ctx, __u64 n)
{
return -ENOSYS;
}
static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n,
unsigned mask)
{
return -ENOSYS;
}
static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
{
}
static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx,
wait_queue_entry_t *wait, __u64 *cnt)
{
return -ENOSYS;
}
static inline bool eventfd_signal_allowed(void)
{
return true;
}
static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt)
{
}
#endif
#endif /* _LINUX_EVENTFD_H */