1 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */ 2 /* 3 * Header file for the io_uring interface. 4 * 5 * Copyright (C) 2019 Jens Axboe 6 * Copyright (C) 2019 Christoph Hellwig 7 */ 8 #ifndef LINUX_IO_URING_H 9 #define LINUX_IO_URING_H 10 11 #include <linux/fs.h> 12 #include <linux/types.h> 13 14 /* 15 * IO submission data structure (Submission Queue Entry) 16 */ 17 struct io_uring_sqe { 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 */ 22 union { 23 __u64 off; /* offset into file */ 24 __u64 addr2; 25 __u32 cmd_op; 26 }; 27 union { 28 __u64 addr; /* pointer to buffer or iovecs */ 29 __u64 splice_off_in; 30 }; 31 __u32 len; /* buffer size or number of iovecs */ 32 union { 33 __kernel_rwf_t rw_flags; 34 __u32 fsync_flags; 35 __u16 poll_events; /* compatibility */ 36 __u32 poll32_events; /* word-reversed for BE */ 37 __u32 sync_range_flags; 38 __u32 msg_flags; 39 __u32 timeout_flags; 40 __u32 accept_flags; 41 __u32 cancel_flags; 42 __u32 open_flags; 43 __u32 statx_flags; 44 __u32 fadvise_advice; 45 __u32 splice_flags; 46 __u32 rename_flags; 47 __u32 unlink_flags; 48 __u32 hardlink_flags; 49 __u32 xattr_flags; 50 __u32 close_flags; 51 }; 52 __u64 user_data; /* data to be passed back at completion time */ 53 /* pack this to avoid bogus arm OABI complaints */ 54 union { 55 /* index into fixed buffers, if used */ 56 __u16 buf_index; 57 /* for grouped buffer selection */ 58 __u16 buf_group; 59 } __attribute__((packed)); 60 /* personality to use, if used */ 61 __u16 personality; 62 union { 63 __s32 splice_fd_in; 64 __u32 file_index; 65 }; 66 union { 67 struct { 68 __u64 addr3; 69 __u64 __pad2[1]; 70 }; 71 /* 72 * If the ring is initialized with IORING_SETUP_SQE128, then 73 * this field is used for 80 bytes of arbitrary command data 74 */ 75 __u8 cmd[0]; 76 }; 77 }; 78 79 /* 80 * If sqe->file_index is set to this for opcodes that instantiate a new 81 * direct descriptor (like openat/openat2/accept), then io_uring will allocate 82 * an available direct descriptor instead of having the application pass one 83 * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE 84 * if the space is full. 85 */ 86 #define IORING_FILE_INDEX_ALLOC (~0U) 87 88 enum { 89 IOSQE_FIXED_FILE_BIT, 90 IOSQE_IO_DRAIN_BIT, 91 IOSQE_IO_LINK_BIT, 92 IOSQE_IO_HARDLINK_BIT, 93 IOSQE_ASYNC_BIT, 94 IOSQE_BUFFER_SELECT_BIT, 95 IOSQE_CQE_SKIP_SUCCESS_BIT, 96 }; 97 98 /* 99 * sqe->flags 100 */ 101 /* use fixed fileset */ 102 #define IOSQE_FIXED_FILE (1U << IOSQE_FIXED_FILE_BIT) 103 /* issue after inflight IO */ 104 #define IOSQE_IO_DRAIN (1U << IOSQE_IO_DRAIN_BIT) 105 /* links next sqe */ 106 #define IOSQE_IO_LINK (1U << IOSQE_IO_LINK_BIT) 107 /* like LINK, but stronger */ 108 #define IOSQE_IO_HARDLINK (1U << IOSQE_IO_HARDLINK_BIT) 109 /* always go async */ 110 #define IOSQE_ASYNC (1U << IOSQE_ASYNC_BIT) 111 /* select buffer from sqe->buf_group */ 112 #define IOSQE_BUFFER_SELECT (1U << IOSQE_BUFFER_SELECT_BIT) 113 /* don't post CQE if request succeeded */ 114 #define IOSQE_CQE_SKIP_SUCCESS (1U << IOSQE_CQE_SKIP_SUCCESS_BIT) 115 116 /* 117 * io_uring_setup() flags 118 */ 119 #define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */ 120 #define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */ 121 #define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */ 122 #define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */ 123 #define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */ 124 #define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */ 125 #define IORING_SETUP_R_DISABLED (1U << 6) /* start with ring disabled */ 126 #define IORING_SETUP_SUBMIT_ALL (1U << 7) /* continue submit on error */ 127 /* 128 * Cooperative task running. When requests complete, they often require 129 * forcing the submitter to transition to the kernel to complete. If this 130 * flag is set, work will be done when the task transitions anyway, rather 131 * than force an inter-processor interrupt reschedule. This avoids interrupting 132 * a task running in userspace, and saves an IPI. 133 */ 134 #define IORING_SETUP_COOP_TASKRUN (1U << 8) 135 /* 136 * If COOP_TASKRUN is set, get notified if task work is available for 137 * running and a kernel transition would be needed to run it. This sets 138 * IORING_SQ_TASKRUN in the sq ring flags. Not valid with COOP_TASKRUN. 139 */ 140 #define IORING_SETUP_TASKRUN_FLAG (1U << 9) 141 142 #define IORING_SETUP_SQE128 (1U << 10) /* SQEs are 128 byte */ 143 #define IORING_SETUP_CQE32 (1U << 11) /* CQEs are 32 byte */ 144 145 enum io_uring_op { 146 IORING_OP_NOP, 147 IORING_OP_READV, 148 IORING_OP_WRITEV, 149 IORING_OP_FSYNC, 150 IORING_OP_READ_FIXED, 151 IORING_OP_WRITE_FIXED, 152 IORING_OP_POLL_ADD, 153 IORING_OP_POLL_REMOVE, 154 IORING_OP_SYNC_FILE_RANGE, 155 IORING_OP_SENDMSG, 156 IORING_OP_RECVMSG, 157 IORING_OP_TIMEOUT, 158 IORING_OP_TIMEOUT_REMOVE, 159 IORING_OP_ACCEPT, 160 IORING_OP_ASYNC_CANCEL, 161 IORING_OP_LINK_TIMEOUT, 162 IORING_OP_CONNECT, 163 IORING_OP_FALLOCATE, 164 IORING_OP_OPENAT, 165 IORING_OP_CLOSE, 166 IORING_OP_FILES_UPDATE, 167 IORING_OP_STATX, 168 IORING_OP_READ, 169 IORING_OP_WRITE, 170 IORING_OP_FADVISE, 171 IORING_OP_MADVISE, 172 IORING_OP_SEND, 173 IORING_OP_RECV, 174 IORING_OP_OPENAT2, 175 IORING_OP_EPOLL_CTL, 176 IORING_OP_SPLICE, 177 IORING_OP_PROVIDE_BUFFERS, 178 IORING_OP_REMOVE_BUFFERS, 179 IORING_OP_TEE, 180 IORING_OP_SHUTDOWN, 181 IORING_OP_RENAMEAT, 182 IORING_OP_UNLINKAT, 183 IORING_OP_MKDIRAT, 184 IORING_OP_SYMLINKAT, 185 IORING_OP_LINKAT, 186 IORING_OP_MSG_RING, 187 IORING_OP_FSETXATTR, 188 IORING_OP_SETXATTR, 189 IORING_OP_FGETXATTR, 190 IORING_OP_GETXATTR, 191 IORING_OP_SOCKET, 192 IORING_OP_URING_CMD, 193 194 /* this goes last, obviously */ 195 IORING_OP_LAST, 196 }; 197 198 /* 199 * sqe->fsync_flags 200 */ 201 #define IORING_FSYNC_DATASYNC (1U << 0) 202 203 /* 204 * sqe->timeout_flags 205 */ 206 #define IORING_TIMEOUT_ABS (1U << 0) 207 #define IORING_TIMEOUT_UPDATE (1U << 1) 208 #define IORING_TIMEOUT_BOOTTIME (1U << 2) 209 #define IORING_TIMEOUT_REALTIME (1U << 3) 210 #define IORING_LINK_TIMEOUT_UPDATE (1U << 4) 211 #define IORING_TIMEOUT_ETIME_SUCCESS (1U << 5) 212 #define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME) 213 #define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE) 214 /* 215 * sqe->splice_flags 216 * extends splice(2) flags 217 */ 218 #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */ 219 220 /* 221 * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the 222 * command flags for POLL_ADD are stored in sqe->len. 223 * 224 * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if 225 * the poll handler will continue to report 226 * CQEs on behalf of the same SQE. 227 * 228 * IORING_POLL_UPDATE Update existing poll request, matching 229 * sqe->addr as the old user_data field. 230 */ 231 #define IORING_POLL_ADD_MULTI (1U << 0) 232 #define IORING_POLL_UPDATE_EVENTS (1U << 1) 233 #define IORING_POLL_UPDATE_USER_DATA (1U << 2) 234 235 /* 236 * ASYNC_CANCEL flags. 237 * 238 * IORING_ASYNC_CANCEL_ALL Cancel all requests that match the given key 239 * IORING_ASYNC_CANCEL_FD Key off 'fd' for cancelation rather than the 240 * request 'user_data' 241 * IORING_ASYNC_CANCEL_ANY Match any request 242 */ 243 #define IORING_ASYNC_CANCEL_ALL (1U << 0) 244 #define IORING_ASYNC_CANCEL_FD (1U << 1) 245 #define IORING_ASYNC_CANCEL_ANY (1U << 2) 246 247 /* 248 * send/sendmsg and recv/recvmsg flags (sqe->addr2) 249 * 250 * IORING_RECVSEND_POLL_FIRST If set, instead of first attempting to send 251 * or receive and arm poll if that yields an 252 * -EAGAIN result, arm poll upfront and skip 253 * the initial transfer attempt. 254 */ 255 #define IORING_RECVSEND_POLL_FIRST (1U << 0) 256 257 /* 258 * accept flags stored in sqe->ioprio 259 */ 260 #define IORING_ACCEPT_MULTISHOT (1U << 0) 261 262 /* 263 * close flags, store in sqe->close_flags 264 */ 265 #define IORING_CLOSE_FD_AND_FILE_SLOT (1U << 0) 266 267 /* 268 * IO completion data structure (Completion Queue Entry) 269 */ 270 struct io_uring_cqe { 271 __u64 user_data; /* sqe->data submission passed back */ 272 __s32 res; /* result code for this event */ 273 __u32 flags; 274 275 /* 276 * If the ring is initialized with IORING_SETUP_CQE32, then this field 277 * contains 16-bytes of padding, doubling the size of the CQE. 278 */ 279 __u64 big_cqe[]; 280 }; 281 282 /* 283 * cqe->flags 284 * 285 * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID 286 * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries 287 * IORING_CQE_F_SOCK_NONEMPTY If set, more data to read after socket recv 288 */ 289 #define IORING_CQE_F_BUFFER (1U << 0) 290 #define IORING_CQE_F_MORE (1U << 1) 291 #define IORING_CQE_F_SOCK_NONEMPTY (1U << 2) 292 293 enum { 294 IORING_CQE_BUFFER_SHIFT = 16, 295 }; 296 297 /* 298 * Magic offsets for the application to mmap the data it needs 299 */ 300 #define IORING_OFF_SQ_RING 0ULL 301 #define IORING_OFF_CQ_RING 0x8000000ULL 302 #define IORING_OFF_SQES 0x10000000ULL 303 304 /* 305 * Filled with the offset for mmap(2) 306 */ 307 struct io_sqring_offsets { 308 __u32 head; 309 __u32 tail; 310 __u32 ring_mask; 311 __u32 ring_entries; 312 __u32 flags; 313 __u32 dropped; 314 __u32 array; 315 __u32 resv1; 316 __u64 resv2; 317 }; 318 319 /* 320 * sq_ring->flags 321 */ 322 #define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */ 323 #define IORING_SQ_CQ_OVERFLOW (1U << 1) /* CQ ring is overflown */ 324 #define IORING_SQ_TASKRUN (1U << 2) /* task should enter the kernel */ 325 326 struct io_cqring_offsets { 327 __u32 head; 328 __u32 tail; 329 __u32 ring_mask; 330 __u32 ring_entries; 331 __u32 overflow; 332 __u32 cqes; 333 __u32 flags; 334 __u32 resv1; 335 __u64 resv2; 336 }; 337 338 /* 339 * cq_ring->flags 340 */ 341 342 /* disable eventfd notifications */ 343 #define IORING_CQ_EVENTFD_DISABLED (1U << 0) 344 345 /* 346 * io_uring_enter(2) flags 347 */ 348 #define IORING_ENTER_GETEVENTS (1U << 0) 349 #define IORING_ENTER_SQ_WAKEUP (1U << 1) 350 #define IORING_ENTER_SQ_WAIT (1U << 2) 351 #define IORING_ENTER_EXT_ARG (1U << 3) 352 #define IORING_ENTER_REGISTERED_RING (1U << 4) 353 354 /* 355 * Passed in for io_uring_setup(2). Copied back with updated info on success 356 */ 357 struct io_uring_params { 358 __u32 sq_entries; 359 __u32 cq_entries; 360 __u32 flags; 361 __u32 sq_thread_cpu; 362 __u32 sq_thread_idle; 363 __u32 features; 364 __u32 wq_fd; 365 __u32 resv[3]; 366 struct io_sqring_offsets sq_off; 367 struct io_cqring_offsets cq_off; 368 }; 369 370 /* 371 * io_uring_params->features flags 372 */ 373 #define IORING_FEAT_SINGLE_MMAP (1U << 0) 374 #define IORING_FEAT_NODROP (1U << 1) 375 #define IORING_FEAT_SUBMIT_STABLE (1U << 2) 376 #define IORING_FEAT_RW_CUR_POS (1U << 3) 377 #define IORING_FEAT_CUR_PERSONALITY (1U << 4) 378 #define IORING_FEAT_FAST_POLL (1U << 5) 379 #define IORING_FEAT_POLL_32BITS (1U << 6) 380 #define IORING_FEAT_SQPOLL_NONFIXED (1U << 7) 381 #define IORING_FEAT_EXT_ARG (1U << 8) 382 #define IORING_FEAT_NATIVE_WORKERS (1U << 9) 383 #define IORING_FEAT_RSRC_TAGS (1U << 10) 384 #define IORING_FEAT_CQE_SKIP (1U << 11) 385 #define IORING_FEAT_LINKED_FILE (1U << 12) 386 387 /* 388 * io_uring_register(2) opcodes and arguments 389 */ 390 enum { 391 IORING_REGISTER_BUFFERS = 0, 392 IORING_UNREGISTER_BUFFERS = 1, 393 IORING_REGISTER_FILES = 2, 394 IORING_UNREGISTER_FILES = 3, 395 IORING_REGISTER_EVENTFD = 4, 396 IORING_UNREGISTER_EVENTFD = 5, 397 IORING_REGISTER_FILES_UPDATE = 6, 398 IORING_REGISTER_EVENTFD_ASYNC = 7, 399 IORING_REGISTER_PROBE = 8, 400 IORING_REGISTER_PERSONALITY = 9, 401 IORING_UNREGISTER_PERSONALITY = 10, 402 IORING_REGISTER_RESTRICTIONS = 11, 403 IORING_REGISTER_ENABLE_RINGS = 12, 404 405 /* extended with tagging */ 406 IORING_REGISTER_FILES2 = 13, 407 IORING_REGISTER_FILES_UPDATE2 = 14, 408 IORING_REGISTER_BUFFERS2 = 15, 409 IORING_REGISTER_BUFFERS_UPDATE = 16, 410 411 /* set/clear io-wq thread affinities */ 412 IORING_REGISTER_IOWQ_AFF = 17, 413 IORING_UNREGISTER_IOWQ_AFF = 18, 414 415 /* set/get max number of io-wq workers */ 416 IORING_REGISTER_IOWQ_MAX_WORKERS = 19, 417 418 /* register/unregister io_uring fd with the ring */ 419 IORING_REGISTER_RING_FDS = 20, 420 IORING_UNREGISTER_RING_FDS = 21, 421 422 /* register ring based provide buffer group */ 423 IORING_REGISTER_PBUF_RING = 22, 424 IORING_UNREGISTER_PBUF_RING = 23, 425 426 /* this goes last */ 427 IORING_REGISTER_LAST 428 }; 429 430 /* io-wq worker categories */ 431 enum { 432 IO_WQ_BOUND, 433 IO_WQ_UNBOUND, 434 }; 435 436 /* deprecated, see struct io_uring_rsrc_update */ 437 struct io_uring_files_update { 438 __u32 offset; 439 __u32 resv; 440 __aligned_u64 /* __s32 * */ fds; 441 }; 442 443 /* 444 * Register a fully sparse file space, rather than pass in an array of all 445 * -1 file descriptors. 446 */ 447 #define IORING_RSRC_REGISTER_SPARSE (1U << 0) 448 449 struct io_uring_rsrc_register { 450 __u32 nr; 451 __u32 flags; 452 __u64 resv2; 453 __aligned_u64 data; 454 __aligned_u64 tags; 455 }; 456 457 struct io_uring_rsrc_update { 458 __u32 offset; 459 __u32 resv; 460 __aligned_u64 data; 461 }; 462 463 struct io_uring_rsrc_update2 { 464 __u32 offset; 465 __u32 resv; 466 __aligned_u64 data; 467 __aligned_u64 tags; 468 __u32 nr; 469 __u32 resv2; 470 }; 471 472 /* Skip updating fd indexes set to this value in the fd table */ 473 #define IORING_REGISTER_FILES_SKIP (-2) 474 475 #define IO_URING_OP_SUPPORTED (1U << 0) 476 477 struct io_uring_probe_op { 478 __u8 op; 479 __u8 resv; 480 __u16 flags; /* IO_URING_OP_* flags */ 481 __u32 resv2; 482 }; 483 484 struct io_uring_probe { 485 __u8 last_op; /* last opcode supported */ 486 __u8 ops_len; /* length of ops[] array below */ 487 __u16 resv; 488 __u32 resv2[3]; 489 struct io_uring_probe_op ops[0]; 490 }; 491 492 struct io_uring_restriction { 493 __u16 opcode; 494 union { 495 __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */ 496 __u8 sqe_op; /* IORING_RESTRICTION_SQE_OP */ 497 __u8 sqe_flags; /* IORING_RESTRICTION_SQE_FLAGS_* */ 498 }; 499 __u8 resv; 500 __u32 resv2[3]; 501 }; 502 503 struct io_uring_buf { 504 __u64 addr; 505 __u32 len; 506 __u16 bid; 507 __u16 resv; 508 }; 509 510 struct io_uring_buf_ring { 511 union { 512 /* 513 * To avoid spilling into more pages than we need to, the 514 * ring tail is overlaid with the io_uring_buf->resv field. 515 */ 516 struct { 517 __u64 resv1; 518 __u32 resv2; 519 __u16 resv3; 520 __u16 tail; 521 }; 522 struct io_uring_buf bufs[0]; 523 }; 524 }; 525 526 /* argument for IORING_(UN)REGISTER_PBUF_RING */ 527 struct io_uring_buf_reg { 528 __u64 ring_addr; 529 __u32 ring_entries; 530 __u16 bgid; 531 __u16 pad; 532 __u64 resv[3]; 533 }; 534 535 /* 536 * io_uring_restriction->opcode values 537 */ 538 enum { 539 /* Allow an io_uring_register(2) opcode */ 540 IORING_RESTRICTION_REGISTER_OP = 0, 541 542 /* Allow an sqe opcode */ 543 IORING_RESTRICTION_SQE_OP = 1, 544 545 /* Allow sqe flags */ 546 IORING_RESTRICTION_SQE_FLAGS_ALLOWED = 2, 547 548 /* Require sqe flags (these flags must be set on each submission) */ 549 IORING_RESTRICTION_SQE_FLAGS_REQUIRED = 3, 550 551 IORING_RESTRICTION_LAST 552 }; 553 554 struct io_uring_getevents_arg { 555 __u64 sigmask; 556 __u32 sigmask_sz; 557 __u32 pad; 558 __u64 ts; 559 }; 560 561 #endif 562