linux-headers/linux/io_uring.h
2023-06-07 11:35:51 +00:00

692 lines
17 KiB
C

/* 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>
#include <linux/time_types.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* 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;
struct {
__u32 cmd_op;
__u32 __pad1;
};
};
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;
__u32 rename_flags;
__u32 unlink_flags;
__u32 hardlink_flags;
__u32 xattr_flags;
__u32 msg_ring_flags;
__u32 uring_cmd_flags;
};
__u64 user_data; /* data to be passed back at completion time */
/* 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;
union {
__s32 splice_fd_in;
__u32 file_index;
struct {
__u16 addr_len;
__u16 __pad3[1];
};
};
union {
struct {
__u64 addr3;
__u64 __pad2[1];
};
/*
* If the ring is initialized with IORING_SETUP_SQE128, then
* this field is used for 80 bytes of arbitrary command data
*/
__u8 cmd[0];
};
};
/*
* If sqe->file_index is set to this for opcodes that instantiate a new
* direct descriptor (like openat/openat2/accept), then io_uring will allocate
* an available direct descriptor instead of having the application pass one
* in. The picked direct descriptor will be returned in cqe->res, or -ENFILE
* if the space is full.
*/
#define IORING_FILE_INDEX_ALLOC (~0U)
enum {
IOSQE_FIXED_FILE_BIT,
IOSQE_IO_DRAIN_BIT,
IOSQE_IO_LINK_BIT,
IOSQE_IO_HARDLINK_BIT,
IOSQE_ASYNC_BIT,
IOSQE_BUFFER_SELECT_BIT,
IOSQE_CQE_SKIP_SUCCESS_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)
/* don't post CQE if request succeeded */
#define IOSQE_CQE_SKIP_SUCCESS (1U << IOSQE_CQE_SKIP_SUCCESS_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 */
#define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */
#define IORING_SETUP_SUBMIT_ALL (1U << 7) /* continue submit on error */
/*
* Cooperative task running. When requests complete, they often require
* forcing the submitter to transition to the kernel to complete. If this
* flag is set, work will be done when the task transitions anyway, rather
* than force an inter-processor interrupt reschedule. This avoids interrupting
* a task running in userspace, and saves an IPI.
*/
#define IORING_SETUP_COOP_TASKRUN (1U << 8)
/*
* If COOP_TASKRUN is set, get notified if task work is available for
* running and a kernel transition would be needed to run it. This sets
* IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
*/
#define IORING_SETUP_TASKRUN_FLAG (1U << 9)
#define IORING_SETUP_SQE128 (1U << 10) /* SQEs are 128 byte */
#define IORING_SETUP_CQE32 (1U << 11) /* CQEs are 32 byte */
/*
* Only one task is allowed to submit requests
*/
#define IORING_SETUP_SINGLE_ISSUER (1U << 12)
/*
* Defer running task work to get events.
* Rather than running bits of task work whenever the task transitions
* try to do it just before it is needed.
*/
#define IORING_SETUP_DEFER_TASKRUN (1U << 13)
enum io_uring_op {
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,
IORING_OP_SHUTDOWN,
IORING_OP_RENAMEAT,
IORING_OP_UNLINKAT,
IORING_OP_MKDIRAT,
IORING_OP_SYMLINKAT,
IORING_OP_LINKAT,
IORING_OP_MSG_RING,
IORING_OP_FSETXATTR,
IORING_OP_SETXATTR,
IORING_OP_FGETXATTR,
IORING_OP_GETXATTR,
IORING_OP_SOCKET,
IORING_OP_URING_CMD,
IORING_OP_SEND_ZC,
IORING_OP_SENDMSG_ZC,
/* this goes last, obviously */
IORING_OP_LAST,
};
/*
* sqe->uring_cmd_flags
* IORING_URING_CMD_FIXED use registered buffer; pass this flag
* along with setting sqe->buf_index.
*/
#define IORING_URING_CMD_FIXED (1U << 0)
/*
* sqe->fsync_flags
*/
#define IORING_FSYNC_DATASYNC (1U << 0)
/*
* sqe->timeout_flags
*/
#define IORING_TIMEOUT_ABS (1U << 0)
#define IORING_TIMEOUT_UPDATE (1U << 1)
#define IORING_TIMEOUT_BOOTTIME (1U << 2)
#define IORING_TIMEOUT_REALTIME (1U << 3)
#define IORING_LINK_TIMEOUT_UPDATE (1U << 4)
#define IORING_TIMEOUT_ETIME_SUCCESS (1U << 5)
#define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
#define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
/*
* sqe->splice_flags
* extends splice(2) flags
*/
#define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
/*
* POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
* command flags for POLL_ADD are stored in sqe->len.
*
* IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
* the poll handler will continue to report
* CQEs on behalf of the same SQE.
*
* IORING_POLL_UPDATE Update existing poll request, matching
* sqe->addr as the old user_data field.
*
* IORING_POLL_LEVEL Level triggered poll.
*/
#define IORING_POLL_ADD_MULTI (1U << 0)
#define IORING_POLL_UPDATE_EVENTS (1U << 1)
#define IORING_POLL_UPDATE_USER_DATA (1U << 2)
#define IORING_POLL_ADD_LEVEL (1U << 3)
/*
* ASYNC_CANCEL flags.
*
* IORING_ASYNC_CANCEL_ALL Cancel all requests that match the given key
* IORING_ASYNC_CANCEL_FD Key off 'fd' for cancelation rather than the
* request 'user_data'
* IORING_ASYNC_CANCEL_ANY Match any request
* IORING_ASYNC_CANCEL_FD_FIXED 'fd' passed in is a fixed descriptor
*/
#define IORING_ASYNC_CANCEL_ALL (1U << 0)
#define IORING_ASYNC_CANCEL_FD (1U << 1)
#define IORING_ASYNC_CANCEL_ANY (1U << 2)
#define IORING_ASYNC_CANCEL_FD_FIXED (1U << 3)
/*
* send/sendmsg and recv/recvmsg flags (sqe->ioprio)
*
* IORING_RECVSEND_POLL_FIRST If set, instead of first attempting to send
* or receive and arm poll if that yields an
* -EAGAIN result, arm poll upfront and skip
* the initial transfer attempt.
*
* IORING_RECV_MULTISHOT Multishot recv. Sets IORING_CQE_F_MORE if
* the handler will continue to report
* CQEs on behalf of the same SQE.
*
* IORING_RECVSEND_FIXED_BUF Use registered buffers, the index is stored in
* the buf_index field.
*
* IORING_SEND_ZC_REPORT_USAGE
* If set, SEND[MSG]_ZC should report
* the zerocopy usage in cqe.res
* for the IORING_CQE_F_NOTIF cqe.
* 0 is reported if zerocopy was actually possible.
* IORING_NOTIF_USAGE_ZC_COPIED if data was copied
* (at least partially).
*/
#define IORING_RECVSEND_POLL_FIRST (1U << 0)
#define IORING_RECV_MULTISHOT (1U << 1)
#define IORING_RECVSEND_FIXED_BUF (1U << 2)
#define IORING_SEND_ZC_REPORT_USAGE (1U << 3)
/*
* cqe.res for IORING_CQE_F_NOTIF if
* IORING_SEND_ZC_REPORT_USAGE was requested
*
* It should be treated as a flag, all other
* bits of cqe.res should be treated as reserved!
*/
#define IORING_NOTIF_USAGE_ZC_COPIED (1U << 31)
/*
* accept flags stored in sqe->ioprio
*/
#define IORING_ACCEPT_MULTISHOT (1U << 0)
/*
* IORING_OP_MSG_RING command types, stored in sqe->addr
*/
enum {
IORING_MSG_DATA, /* pass sqe->len as 'res' and off as user_data */
IORING_MSG_SEND_FD, /* send a registered fd to another ring */
};
/*
* IORING_OP_MSG_RING flags (sqe->msg_ring_flags)
*
* IORING_MSG_RING_CQE_SKIP Don't post a CQE to the target ring. Not
* applicable for IORING_MSG_DATA, obviously.
*/
#define IORING_MSG_RING_CQE_SKIP (1U << 0)
/*
* 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;
/*
* If the ring is initialized with IORING_SETUP_CQE32, then this field
* contains 16-bytes of padding, doubling the size of the CQE.
*/
__u64 big_cqe[];
};
/*
* cqe->flags
*
* IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
* IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries
* IORING_CQE_F_SOCK_NONEMPTY If set, more data to read after socket recv
* IORING_CQE_F_NOTIF Set for notification CQEs. Can be used to distinct
* them from sends.
*/
#define IORING_CQE_F_BUFFER (1U << 0)
#define IORING_CQE_F_MORE (1U << 1)
#define IORING_CQE_F_SOCK_NONEMPTY (1U << 2)
#define IORING_CQE_F_NOTIF (1U << 3)
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 */
#define IORING_SQ_TASKRUN (1U << 2) /* task should enter the kernel */
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)
#define IORING_ENTER_SQ_WAIT (1U << 2)
#define IORING_ENTER_EXT_ARG (1U << 3)
#define IORING_ENTER_REGISTERED_RING (1U << 4)
/*
* 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)
#define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
#define IORING_FEAT_EXT_ARG (1U << 8)
#define IORING_FEAT_NATIVE_WORKERS (1U << 9)
#define IORING_FEAT_RSRC_TAGS (1U << 10)
#define IORING_FEAT_CQE_SKIP (1U << 11)
#define IORING_FEAT_LINKED_FILE (1U << 12)
/*
* io_uring_register(2) opcodes and arguments
*/
enum {
IORING_REGISTER_BUFFERS = 0,
IORING_UNREGISTER_BUFFERS = 1,
IORING_REGISTER_FILES = 2,
IORING_UNREGISTER_FILES = 3,
IORING_REGISTER_EVENTFD = 4,
IORING_UNREGISTER_EVENTFD = 5,
IORING_REGISTER_FILES_UPDATE = 6,
IORING_REGISTER_EVENTFD_ASYNC = 7,
IORING_REGISTER_PROBE = 8,
IORING_REGISTER_PERSONALITY = 9,
IORING_UNREGISTER_PERSONALITY = 10,
IORING_REGISTER_RESTRICTIONS = 11,
IORING_REGISTER_ENABLE_RINGS = 12,
/* extended with tagging */
IORING_REGISTER_FILES2 = 13,
IORING_REGISTER_FILES_UPDATE2 = 14,
IORING_REGISTER_BUFFERS2 = 15,
IORING_REGISTER_BUFFERS_UPDATE = 16,
/* set/clear io-wq thread affinities */
IORING_REGISTER_IOWQ_AFF = 17,
IORING_UNREGISTER_IOWQ_AFF = 18,
/* set/get max number of io-wq workers */
IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
/* register/unregister io_uring fd with the ring */
IORING_REGISTER_RING_FDS = 20,
IORING_UNREGISTER_RING_FDS = 21,
/* register ring based provide buffer group */
IORING_REGISTER_PBUF_RING = 22,
IORING_UNREGISTER_PBUF_RING = 23,
/* sync cancelation API */
IORING_REGISTER_SYNC_CANCEL = 24,
/* register a range of fixed file slots for automatic slot allocation */
IORING_REGISTER_FILE_ALLOC_RANGE = 25,
/* this goes last */
IORING_REGISTER_LAST
};
/* io-wq worker categories */
enum {
IO_WQ_BOUND,
IO_WQ_UNBOUND,
};
/* deprecated, see struct io_uring_rsrc_update */
struct io_uring_files_update {
__u32 offset;
__u32 resv;
__aligned_u64 /* __s32 * */ fds;
};
/*
* Register a fully sparse file space, rather than pass in an array of all
* -1 file descriptors.
*/
#define IORING_RSRC_REGISTER_SPARSE (1U << 0)
struct io_uring_rsrc_register {
__u32 nr;
__u32 flags;
__u64 resv2;
__aligned_u64 data;
__aligned_u64 tags;
};
struct io_uring_rsrc_update {
__u32 offset;
__u32 resv;
__aligned_u64 data;
};
struct io_uring_rsrc_update2 {
__u32 offset;
__u32 resv;
__aligned_u64 data;
__aligned_u64 tags;
__u32 nr;
__u32 resv2;
};
struct io_uring_notification_slot {
__u64 tag;
__u64 resv[3];
};
struct io_uring_notification_register {
__u32 nr_slots;
__u32 resv;
__u64 resv2;
__u64 data;
__u64 resv3;
};
/* Skip updating fd indexes set to this value in the fd table */
#define IORING_REGISTER_FILES_SKIP (-2)
#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[];
};
struct io_uring_restriction {
__u16 opcode;
union {
__u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
__u8 sqe_op; /* IORING_RESTRICTION_SQE_OP */
__u8 sqe_flags; /* IORING_RESTRICTION_SQE_FLAGS_* */
};
__u8 resv;
__u32 resv2[3];
};
struct io_uring_buf {
__u64 addr;
__u32 len;
__u16 bid;
__u16 resv;
};
struct io_uring_buf_ring {
union {
/*
* To avoid spilling into more pages than we need to, the
* ring tail is overlaid with the io_uring_buf->resv field.
*/
struct {
__u64 resv1;
__u32 resv2;
__u16 resv3;
__u16 tail;
};
__DECLARE_FLEX_ARRAY(struct io_uring_buf, bufs);
};
};
/* argument for IORING_(UN)REGISTER_PBUF_RING */
struct io_uring_buf_reg {
__u64 ring_addr;
__u32 ring_entries;
__u16 bgid;
__u16 pad;
__u64 resv[3];
};
/*
* io_uring_restriction->opcode values
*/
enum {
/* Allow an io_uring_register(2) opcode */
IORING_RESTRICTION_REGISTER_OP = 0,
/* Allow an sqe opcode */
IORING_RESTRICTION_SQE_OP = 1,
/* Allow sqe flags */
IORING_RESTRICTION_SQE_FLAGS_ALLOWED = 2,
/* Require sqe flags (these flags must be set on each submission) */
IORING_RESTRICTION_SQE_FLAGS_REQUIRED = 3,
IORING_RESTRICTION_LAST
};
struct io_uring_getevents_arg {
__u64 sigmask;
__u32 sigmask_sz;
__u32 pad;
__u64 ts;
};
/*
* Argument for IORING_REGISTER_SYNC_CANCEL
*/
struct io_uring_sync_cancel_reg {
__u64 addr;
__s32 fd;
__u32 flags;
struct __kernel_timespec timeout;
__u64 pad[4];
};
/*
* Argument for IORING_REGISTER_FILE_ALLOC_RANGE
* The range is specified as [off, off + len)
*/
struct io_uring_file_index_range {
__u32 off;
__u32 len;
__u64 resv;
};
struct io_uring_recvmsg_out {
__u32 namelen;
__u32 controllen;
__u32 payloadlen;
__u32 flags;
};
#ifdef __cplusplus
}
#endif
#endif