io_uring.h
/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
/*
* Header file for the io_uring interface.
*
* Copyright (C) 2019 Jens Axboe
* Copyright (C) 2019 Christoph Hellwig
*/
#ifndef LINUX_IO_URING_H
#define LINUX_IO_URING_H
#include <linux/fs.h>
#include <linux/types.h>
/*
* IO submission data structure (Submission Queue Entry)
*/
struct io_uring_sqe {
__u8 opcode; /* type of operation for this sqe */
__u8 flags; /* IOSQE_ flags */
__u16 ioprio; /* ioprio for the request */
__s32 fd; /* file descriptor to do IO on */
union {
__u64 off; /* offset into file */
__u64 addr2;
};
union {
__u64 addr; /* pointer to buffer or iovecs */
__u64 splice_off_in;
};
__u32 len; /* buffer size or number of iovecs */
union {
__kernel_rwf_t rw_flags;
__u32 fsync_flags;
__u16 poll_events; /* compatibility */
__u32 poll32_events; /* word-reversed for BE */
__u32 sync_range_flags;
__u32 msg_flags;
__u32 timeout_flags;
__u32 accept_flags;
__u32 cancel_flags;
__u32 open_flags;
__u32 statx_flags;
__u32 fadvise_advice;
__u32 splice_flags;
};
__u64 user_data; /* data to be passed back at completion time */
union {
struct {
/* pack this to avoid bogus arm OABI complaints */
union {
/* index into fixed buffers, if used */
__u16 buf_index;
/* for grouped buffer selection */
__u16 buf_group;
} __attribute__((packed));
/* personality to use, if used */
__u16 personality;
__s32 splice_fd_in;
};
__u64 __pad2[3];
};
};
enum {
IOSQE_FIXED_FILE_BIT,
IOSQE_IO_DRAIN_BIT,
IOSQE_IO_LINK_BIT,
IOSQE_IO_HARDLINK_BIT,
IOSQE_ASYNC_BIT,
IOSQE_BUFFER_SELECT_BIT,
};
/*
* sqe->flags
*/
/* use fixed fileset */
#define IOSQE_FIXED_FILE (1U << IOSQE_FIXED_FILE_BIT)
/* issue after inflight IO */
#define IOSQE_IO_DRAIN (1U << IOSQE_IO_DRAIN_BIT)
/* links next sqe */
#define IOSQE_IO_LINK (1U << IOSQE_IO_LINK_BIT)
/* like LINK, but stronger */
#define IOSQE_IO_HARDLINK (1U << IOSQE_IO_HARDLINK_BIT)
/* always go async */
#define IOSQE_ASYNC (1U << IOSQE_ASYNC_BIT)
/* select buffer from sqe->buf_group */
#define IOSQE_BUFFER_SELECT (1U << IOSQE_BUFFER_SELECT_BIT)
/*
* io_uring_setup() flags
*/
#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
#define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
#define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
#define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
enum {
IORING_OP_NOP,
IORING_OP_READV,
IORING_OP_WRITEV,
IORING_OP_FSYNC,
IORING_OP_READ_FIXED,
IORING_OP_WRITE_FIXED,
IORING_OP_POLL_ADD,
IORING_OP_POLL_REMOVE,
IORING_OP_SYNC_FILE_RANGE,
IORING_OP_SENDMSG,
IORING_OP_RECVMSG,
IORING_OP_TIMEOUT,
IORING_OP_TIMEOUT_REMOVE,
IORING_OP_ACCEPT,
IORING_OP_ASYNC_CANCEL,
IORING_OP_LINK_TIMEOUT,
IORING_OP_CONNECT,
IORING_OP_FALLOCATE,
IORING_OP_OPENAT,
IORING_OP_CLOSE,
IORING_OP_FILES_UPDATE,
IORING_OP_STATX,
IORING_OP_READ,
IORING_OP_WRITE,
IORING_OP_FADVISE,
IORING_OP_MADVISE,
IORING_OP_SEND,
IORING_OP_RECV,
IORING_OP_OPENAT2,
IORING_OP_EPOLL_CTL,
IORING_OP_SPLICE,
IORING_OP_PROVIDE_BUFFERS,
IORING_OP_REMOVE_BUFFERS,
IORING_OP_TEE,
/* this goes last, obviously */
IORING_OP_LAST,
};
/*
* sqe->fsync_flags
*/
#define IORING_FSYNC_DATASYNC (1U << 0)
/*
* sqe->timeout_flags
*/
#define IORING_TIMEOUT_ABS (1U << 0)
/*
* sqe->splice_flags
* extends splice(2) flags
*/
#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
/*
* IO completion data structure (Completion Queue Entry)
*/
struct io_uring_cqe {
__u64 user_data; /* sqe->data submission passed back */
__s32 res; /* result code for this event */
__u32 flags;
};
/*
* cqe->flags
*
* IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
*/
#define IORING_CQE_F_BUFFER (1U << 0)
enum {
IORING_CQE_BUFFER_SHIFT = 16,
};
/*
* Magic offsets for the application to mmap the data it needs
*/
#define IORING_OFF_SQ_RING 0ULL
#define IORING_OFF_CQ_RING 0x8000000ULL
#define IORING_OFF_SQES 0x10000000ULL
/*
* Filled with the offset for mmap(2)
*/
struct io_sqring_offsets {
__u32 head;
__u32 tail;
__u32 ring_mask;
__u32 ring_entries;
__u32 flags;
__u32 dropped;
__u32 array;
__u32 resv1;
__u64 resv2;
};
/*
* sq_ring->flags
*/
#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
#define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */
struct io_cqring_offsets {
__u32 head;
__u32 tail;
__u32 ring_mask;
__u32 ring_entries;
__u32 overflow;
__u32 cqes;
__u32 flags;
__u32 resv1;
__u64 resv2;
};
/*
* cq_ring->flags
*/
/* disable eventfd notifications */
#define IORING_CQ_EVENTFD_DISABLED (1U << 0)
/*
* io_uring_enter(2) flags
*/
#define IORING_ENTER_GETEVENTS (1U << 0)
#define IORING_ENTER_SQ_WAKEUP (1U << 1)
/*
* Passed in for io_uring_setup(2). Copied back with updated info on success
*/
struct io_uring_params {
__u32 sq_entries;
__u32 cq_entries;
__u32 flags;
__u32 sq_thread_cpu;
__u32 sq_thread_idle;
__u32 features;
__u32 wq_fd;
__u32 resv[3];
struct io_sqring_offsets sq_off;
struct io_cqring_offsets cq_off;
};
/*
* io_uring_params->features flags
*/
#define IORING_FEAT_SINGLE_MMAP (1U << 0)
#define IORING_FEAT_NODROP (1U << 1)
#define IORING_FEAT_SUBMIT_STABLE (1U << 2)
#define IORING_FEAT_RW_CUR_POS (1U << 3)
#define IORING_FEAT_CUR_PERSONALITY (1U << 4)
#define IORING_FEAT_FAST_POLL (1U << 5)
#define IORING_FEAT_POLL_32BITS (1U << 6)
/*
* io_uring_register(2) opcodes and arguments
*/
#define IORING_REGISTER_BUFFERS 0
#define IORING_UNREGISTER_BUFFERS 1
#define IORING_REGISTER_FILES 2
#define IORING_UNREGISTER_FILES 3
#define IORING_REGISTER_EVENTFD 4
#define IORING_UNREGISTER_EVENTFD 5
#define IORING_REGISTER_FILES_UPDATE 6
#define IORING_REGISTER_EVENTFD_ASYNC 7
#define IORING_REGISTER_PROBE 8
#define IORING_REGISTER_PERSONALITY 9
#define IORING_UNREGISTER_PERSONALITY 10
struct io_uring_files_update {
__u32 offset;
__u32 resv;
__aligned_u64 /* __s32 * */ fds;
};
#define IO_URING_OP_SUPPORTED (1U << 0)
struct io_uring_probe_op {
__u8 op;
__u8 resv;
__u16 flags; /* IO_URING_OP_* flags */
__u32 resv2;
};
struct io_uring_probe {
__u8 last_op; /* last opcode supported */
__u8 ops_len; /* length of ops[] array below */
__u16 resv;
__u32 resv2[3];
struct io_uring_probe_op ops[0];
};
#endif