1 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
3 * Header file for the io_uring interface.
5 * Copyright (C) 2019 Jens Axboe
6 * Copyright (C) 2019 Christoph Hellwig
8 #ifndef LINUX_IO_URING_H
9 #define LINUX_IO_URING_H
12 #include <linux/types.h>
15 * IO submission data structure (Submission Queue Entry)
18 __u8 opcode; /* type of operation for this sqe */
19 __u8 flags; /* IOSQE_ flags */
20 __u16 ioprio; /* ioprio for the request */
21 __s32 fd; /* file descriptor to do IO on */
23 __u64 off; /* offset into file */
31 __u64 addr; /* pointer to buffer or iovecs */
34 __u32 len; /* buffer size or number of iovecs */
36 __kernel_rwf_t rw_flags;
38 __u16 poll_events; /* compatibility */
39 __u32 poll32_events; /* word-reversed for BE */
40 __u32 sync_range_flags;
54 __u64 user_data; /* data to be passed back at completion time */
55 /* pack this to avoid bogus arm OABI complaints */
57 /* index into fixed buffers, if used */
59 /* for grouped buffer selection */
61 } __attribute__((packed));
62 /* personality to use, if used */
74 * If the ring is initialized with IORING_SETUP_SQE128, then
75 * this field is used for 80 bytes of arbitrary command data
82 * If sqe->file_index is set to this for opcodes that instantiate a new
83 * direct descriptor (like openat/openat2/accept), then io_uring will allocate
84 * an available direct descriptor instead of having the application pass one
85 * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE
86 * if the space is full.
88 #define IORING_FILE_INDEX_ALLOC (~0U)
94 IOSQE_IO_HARDLINK_BIT,
96 IOSQE_BUFFER_SELECT_BIT,
97 IOSQE_CQE_SKIP_SUCCESS_BIT,
103 /* use fixed fileset */
104 #define IOSQE_FIXED_FILE (1U << IOSQE_FIXED_FILE_BIT)
105 /* issue after inflight IO */
106 #define IOSQE_IO_DRAIN (1U << IOSQE_IO_DRAIN_BIT)
108 #define IOSQE_IO_LINK (1U << IOSQE_IO_LINK_BIT)
109 /* like LINK, but stronger */
110 #define IOSQE_IO_HARDLINK (1U << IOSQE_IO_HARDLINK_BIT)
111 /* always go async */
112 #define IOSQE_ASYNC (1U << IOSQE_ASYNC_BIT)
113 /* select buffer from sqe->buf_group */
114 #define IOSQE_BUFFER_SELECT (1U << IOSQE_BUFFER_SELECT_BIT)
115 /* don't post CQE if request succeeded */
116 #define IOSQE_CQE_SKIP_SUCCESS (1U << IOSQE_CQE_SKIP_SUCCESS_BIT)
119 * io_uring_setup() flags
121 #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
122 #define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
123 #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
124 #define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
125 #define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
126 #define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
127 #define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */
128 #define IORING_SETUP_SUBMIT_ALL (1U << 7) /* continue submit on error */
130 * Cooperative task running. When requests complete, they often require
131 * forcing the submitter to transition to the kernel to complete. If this
132 * flag is set, work will be done when the task transitions anyway, rather
133 * than force an inter-processor interrupt reschedule. This avoids interrupting
134 * a task running in userspace, and saves an IPI.
136 #define IORING_SETUP_COOP_TASKRUN (1U << 8)
138 * If COOP_TASKRUN is set, get notified if task work is available for
139 * running and a kernel transition would be needed to run it. This sets
140 * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN.
142 #define IORING_SETUP_TASKRUN_FLAG (1U << 9)
144 #define IORING_SETUP_SQE128 (1U << 10) /* SQEs are 128 byte */
145 #define IORING_SETUP_CQE32 (1U << 11) /* CQEs are 32 byte */
152 IORING_OP_READ_FIXED,
153 IORING_OP_WRITE_FIXED,
155 IORING_OP_POLL_REMOVE,
156 IORING_OP_SYNC_FILE_RANGE,
160 IORING_OP_TIMEOUT_REMOVE,
162 IORING_OP_ASYNC_CANCEL,
163 IORING_OP_LINK_TIMEOUT,
168 IORING_OP_FILES_UPDATE,
179 IORING_OP_PROVIDE_BUFFERS,
180 IORING_OP_REMOVE_BUFFERS,
196 /* this goes last, obviously */
203 #define IORING_FSYNC_DATASYNC (1U << 0)
208 #define IORING_TIMEOUT_ABS (1U << 0)
209 #define IORING_TIMEOUT_UPDATE (1U << 1)
210 #define IORING_TIMEOUT_BOOTTIME (1U << 2)
211 #define IORING_TIMEOUT_REALTIME (1U << 3)
212 #define IORING_LINK_TIMEOUT_UPDATE (1U << 4)
213 #define IORING_TIMEOUT_ETIME_SUCCESS (1U << 5)
214 #define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
215 #define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
218 * extends splice(2) flags
220 #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
223 * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
224 * command flags for POLL_ADD are stored in sqe->len.
226 * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
227 * the poll handler will continue to report
228 * CQEs on behalf of the same SQE.
230 * IORING_POLL_UPDATE Update existing poll request, matching
231 * sqe->addr as the old user_data field.
233 #define IORING_POLL_ADD_MULTI (1U << 0)
234 #define IORING_POLL_UPDATE_EVENTS (1U << 1)
235 #define IORING_POLL_UPDATE_USER_DATA (1U << 2)
238 * ASYNC_CANCEL flags.
240 * IORING_ASYNC_CANCEL_ALL Cancel all requests that match the given key
241 * IORING_ASYNC_CANCEL_FD Key off 'fd' for cancelation rather than the
242 * request 'user_data'
243 * IORING_ASYNC_CANCEL_ANY Match any request
245 #define IORING_ASYNC_CANCEL_ALL (1U << 0)
246 #define IORING_ASYNC_CANCEL_FD (1U << 1)
247 #define IORING_ASYNC_CANCEL_ANY (1U << 2)
250 * send/sendmsg and recv/recvmsg flags (sqe->ioprio)
252 * IORING_RECVSEND_POLL_FIRST If set, instead of first attempting to send
253 * or receive and arm poll if that yields an
254 * -EAGAIN result, arm poll upfront and skip
255 * the initial transfer attempt.
257 #define IORING_RECVSEND_POLL_FIRST (1U << 0)
260 * accept flags stored in sqe->ioprio
262 #define IORING_ACCEPT_MULTISHOT (1U << 0)
265 * IO completion data structure (Completion Queue Entry)
267 struct io_uring_cqe {
268 __u64 user_data; /* sqe->data submission passed back */
269 __s32 res; /* result code for this event */
273 * If the ring is initialized with IORING_SETUP_CQE32, then this field
274 * contains 16-bytes of padding, doubling the size of the CQE.
282 * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
283 * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries
284 * IORING_CQE_F_SOCK_NONEMPTY If set, more data to read after socket recv
286 #define IORING_CQE_F_BUFFER (1U << 0)
287 #define IORING_CQE_F_MORE (1U << 1)
288 #define IORING_CQE_F_SOCK_NONEMPTY (1U << 2)
291 IORING_CQE_BUFFER_SHIFT = 16,
295 * Magic offsets for the application to mmap the data it needs
297 #define IORING_OFF_SQ_RING 0ULL
298 #define IORING_OFF_CQ_RING 0x8000000ULL
299 #define IORING_OFF_SQES 0x10000000ULL
302 * Filled with the offset for mmap(2)
304 struct io_sqring_offsets {
319 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
320 #define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */
321 #define IORING_SQ_TASKRUN (1U << 2) /* task should enter the kernel */
323 struct io_cqring_offsets {
339 /* disable eventfd notifications */
340 #define IORING_CQ_EVENTFD_DISABLED (1U << 0)
343 * io_uring_enter(2) flags
345 #define IORING_ENTER_GETEVENTS (1U << 0)
346 #define IORING_ENTER_SQ_WAKEUP (1U << 1)
347 #define IORING_ENTER_SQ_WAIT (1U << 2)
348 #define IORING_ENTER_EXT_ARG (1U << 3)
349 #define IORING_ENTER_REGISTERED_RING (1U << 4)
352 * Passed in for io_uring_setup(2). Copied back with updated info on success
354 struct io_uring_params {
359 __u32 sq_thread_idle;
363 struct io_sqring_offsets sq_off;
364 struct io_cqring_offsets cq_off;
368 * io_uring_params->features flags
370 #define IORING_FEAT_SINGLE_MMAP (1U << 0)
371 #define IORING_FEAT_NODROP (1U << 1)
372 #define IORING_FEAT_SUBMIT_STABLE (1U << 2)
373 #define IORING_FEAT_RW_CUR_POS (1U << 3)
374 #define IORING_FEAT_CUR_PERSONALITY (1U << 4)
375 #define IORING_FEAT_FAST_POLL (1U << 5)
376 #define IORING_FEAT_POLL_32BITS (1U << 6)
377 #define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
378 #define IORING_FEAT_EXT_ARG (1U << 8)
379 #define IORING_FEAT_NATIVE_WORKERS (1U << 9)
380 #define IORING_FEAT_RSRC_TAGS (1U << 10)
381 #define IORING_FEAT_CQE_SKIP (1U << 11)
382 #define IORING_FEAT_LINKED_FILE (1U << 12)
385 * io_uring_register(2) opcodes and arguments
388 IORING_REGISTER_BUFFERS = 0,
389 IORING_UNREGISTER_BUFFERS = 1,
390 IORING_REGISTER_FILES = 2,
391 IORING_UNREGISTER_FILES = 3,
392 IORING_REGISTER_EVENTFD = 4,
393 IORING_UNREGISTER_EVENTFD = 5,
394 IORING_REGISTER_FILES_UPDATE = 6,
395 IORING_REGISTER_EVENTFD_ASYNC = 7,
396 IORING_REGISTER_PROBE = 8,
397 IORING_REGISTER_PERSONALITY = 9,
398 IORING_UNREGISTER_PERSONALITY = 10,
399 IORING_REGISTER_RESTRICTIONS = 11,
400 IORING_REGISTER_ENABLE_RINGS = 12,
402 /* extended with tagging */
403 IORING_REGISTER_FILES2 = 13,
404 IORING_REGISTER_FILES_UPDATE2 = 14,
405 IORING_REGISTER_BUFFERS2 = 15,
406 IORING_REGISTER_BUFFERS_UPDATE = 16,
408 /* set/clear io-wq thread affinities */
409 IORING_REGISTER_IOWQ_AFF = 17,
410 IORING_UNREGISTER_IOWQ_AFF = 18,
412 /* set/get max number of io-wq workers */
413 IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
415 /* register/unregister io_uring fd with the ring */
416 IORING_REGISTER_RING_FDS = 20,
417 IORING_UNREGISTER_RING_FDS = 21,
419 /* register ring based provide buffer group */
420 IORING_REGISTER_PBUF_RING = 22,
421 IORING_UNREGISTER_PBUF_RING = 23,
427 /* io-wq worker categories */
433 /* deprecated, see struct io_uring_rsrc_update */
434 struct io_uring_files_update {
437 __aligned_u64 /* __s32 * */ fds;
441 * Register a fully sparse file space, rather than pass in an array of all
442 * -1 file descriptors.
444 #define IORING_RSRC_REGISTER_SPARSE (1U << 0)
446 struct io_uring_rsrc_register {
454 struct io_uring_rsrc_update {
460 struct io_uring_rsrc_update2 {
469 /* Skip updating fd indexes set to this value in the fd table */
470 #define IORING_REGISTER_FILES_SKIP (-2)
472 #define IO_URING_OP_SUPPORTED (1U << 0)
474 struct io_uring_probe_op {
477 __u16 flags; /* IO_URING_OP_* flags */
481 struct io_uring_probe {
482 __u8 last_op; /* last opcode supported */
483 __u8 ops_len; /* length of ops[] array below */
486 struct io_uring_probe_op ops[0];
489 struct io_uring_restriction {
492 __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */
493 __u8 sqe_op; /* IORING_RESTRICTION_SQE_OP */
494 __u8 sqe_flags; /* IORING_RESTRICTION_SQE_FLAGS_* */
500 struct io_uring_buf {
507 struct io_uring_buf_ring {
510 * To avoid spilling into more pages than we need to, the
511 * ring tail is overlaid with the io_uring_buf->resv field.
519 struct io_uring_buf bufs[0];
523 /* argument for IORING_(UN)REGISTER_PBUF_RING */
524 struct io_uring_buf_reg {
533 * io_uring_restriction->opcode values
536 /* Allow an io_uring_register(2) opcode */
537 IORING_RESTRICTION_REGISTER_OP = 0,
539 /* Allow an sqe opcode */
540 IORING_RESTRICTION_SQE_OP = 1,
542 /* Allow sqe flags */
543 IORING_RESTRICTION_SQE_FLAGS_ALLOWED = 2,
545 /* Require sqe flags (these flags must be set on each submission) */
546 IORING_RESTRICTION_SQE_FLAGS_REQUIRED = 3,
548 IORING_RESTRICTION_LAST
551 struct io_uring_getevents_arg {