1 #ifndef IO_URING_TYPES_H 2 #define IO_URING_TYPES_H 3 4 #include <linux/blkdev.h> 5 #include <linux/task_work.h> 6 #include <linux/bitmap.h> 7 #include <linux/llist.h> 8 #include <uapi/linux/io_uring.h> 9 10 enum { 11 /* 12 * A hint to not wake right away but delay until there are enough of 13 * tw's queued to match the number of CQEs the task is waiting for. 14 * 15 * Must not be used wirh requests generating more than one CQE. 16 * It's also ignored unless IORING_SETUP_DEFER_TASKRUN is set. 17 */ 18 IOU_F_TWQ_LAZY_WAKE = 1, 19 }; 20 21 enum io_uring_cmd_flags { 22 IO_URING_F_COMPLETE_DEFER = 1, 23 IO_URING_F_UNLOCKED = 2, 24 /* the request is executed from poll, it should not be freed */ 25 IO_URING_F_MULTISHOT = 4, 26 /* executed by io-wq */ 27 IO_URING_F_IOWQ = 8, 28 /* int's last bit, sign checks are usually faster than a bit test */ 29 IO_URING_F_NONBLOCK = INT_MIN, 30 31 /* ctx state flags, for URING_CMD */ 32 IO_URING_F_SQE128 = (1 << 8), 33 IO_URING_F_CQE32 = (1 << 9), 34 IO_URING_F_IOPOLL = (1 << 10), 35 36 /* set when uring wants to cancel a previously issued command */ 37 IO_URING_F_CANCEL = (1 << 11), 38 IO_URING_F_COMPAT = (1 << 12), 39 }; 40 41 struct io_wq_work_node { 42 struct io_wq_work_node *next; 43 }; 44 45 struct io_wq_work_list { 46 struct io_wq_work_node *first; 47 struct io_wq_work_node *last; 48 }; 49 50 struct io_wq_work { 51 struct io_wq_work_node list; 52 unsigned flags; 53 /* place it here instead of io_kiocb as it fills padding and saves 4B */ 54 int cancel_seq; 55 }; 56 57 struct io_fixed_file { 58 /* file * with additional FFS_* flags */ 59 unsigned long file_ptr; 60 }; 61 62 struct io_file_table { 63 struct io_fixed_file *files; 64 unsigned long *bitmap; 65 unsigned int alloc_hint; 66 }; 67 68 struct io_hash_bucket { 69 spinlock_t lock; 70 struct hlist_head list; 71 } ____cacheline_aligned_in_smp; 72 73 struct io_hash_table { 74 struct io_hash_bucket *hbs; 75 unsigned hash_bits; 76 }; 77 78 /* 79 * Arbitrary limit, can be raised if need be 80 */ 81 #define IO_RINGFD_REG_MAX 16 82 83 struct io_uring_task { 84 /* submission side */ 85 int cached_refs; 86 const struct io_ring_ctx *last; 87 struct io_wq *io_wq; 88 struct file *registered_rings[IO_RINGFD_REG_MAX]; 89 90 struct xarray xa; 91 struct wait_queue_head wait; 92 atomic_t in_cancel; 93 atomic_t inflight_tracked; 94 struct percpu_counter inflight; 95 96 struct { /* task_work */ 97 struct llist_head task_list; 98 struct callback_head task_work; 99 } ____cacheline_aligned_in_smp; 100 }; 101 102 struct io_uring { 103 u32 head; 104 u32 tail; 105 }; 106 107 /* 108 * This data is shared with the application through the mmap at offsets 109 * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING. 110 * 111 * The offsets to the member fields are published through struct 112 * io_sqring_offsets when calling io_uring_setup. 113 */ 114 struct io_rings { 115 /* 116 * Head and tail offsets into the ring; the offsets need to be 117 * masked to get valid indices. 118 * 119 * The kernel controls head of the sq ring and the tail of the cq ring, 120 * and the application controls tail of the sq ring and the head of the 121 * cq ring. 122 */ 123 struct io_uring sq, cq; 124 /* 125 * Bitmasks to apply to head and tail offsets (constant, equals 126 * ring_entries - 1) 127 */ 128 u32 sq_ring_mask, cq_ring_mask; 129 /* Ring sizes (constant, power of 2) */ 130 u32 sq_ring_entries, cq_ring_entries; 131 /* 132 * Number of invalid entries dropped by the kernel due to 133 * invalid index stored in array 134 * 135 * Written by the kernel, shouldn't be modified by the 136 * application (i.e. get number of "new events" by comparing to 137 * cached value). 138 * 139 * After a new SQ head value was read by the application this 140 * counter includes all submissions that were dropped reaching 141 * the new SQ head (and possibly more). 142 */ 143 u32 sq_dropped; 144 /* 145 * Runtime SQ flags 146 * 147 * Written by the kernel, shouldn't be modified by the 148 * application. 149 * 150 * The application needs a full memory barrier before checking 151 * for IORING_SQ_NEED_WAKEUP after updating the sq tail. 152 */ 153 atomic_t sq_flags; 154 /* 155 * Runtime CQ flags 156 * 157 * Written by the application, shouldn't be modified by the 158 * kernel. 159 */ 160 u32 cq_flags; 161 /* 162 * Number of completion events lost because the queue was full; 163 * this should be avoided by the application by making sure 164 * there are not more requests pending than there is space in 165 * the completion queue. 166 * 167 * Written by the kernel, shouldn't be modified by the 168 * application (i.e. get number of "new events" by comparing to 169 * cached value). 170 * 171 * As completion events come in out of order this counter is not 172 * ordered with any other data. 173 */ 174 u32 cq_overflow; 175 /* 176 * Ring buffer of completion events. 177 * 178 * The kernel writes completion events fresh every time they are 179 * produced, so the application is allowed to modify pending 180 * entries. 181 */ 182 struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; 183 }; 184 185 struct io_restriction { 186 DECLARE_BITMAP(register_op, IORING_REGISTER_LAST); 187 DECLARE_BITMAP(sqe_op, IORING_OP_LAST); 188 u8 sqe_flags_allowed; 189 u8 sqe_flags_required; 190 bool registered; 191 }; 192 193 struct io_submit_link { 194 struct io_kiocb *head; 195 struct io_kiocb *last; 196 }; 197 198 struct io_submit_state { 199 /* inline/task_work completion list, under ->uring_lock */ 200 struct io_wq_work_node free_list; 201 /* batch completion logic */ 202 struct io_wq_work_list compl_reqs; 203 struct io_submit_link link; 204 205 bool plug_started; 206 bool need_plug; 207 unsigned short submit_nr; 208 unsigned int cqes_count; 209 struct blk_plug plug; 210 }; 211 212 struct io_ev_fd { 213 struct eventfd_ctx *cq_ev_fd; 214 unsigned int eventfd_async: 1; 215 struct rcu_head rcu; 216 atomic_t refs; 217 atomic_t ops; 218 }; 219 220 struct io_alloc_cache { 221 struct io_wq_work_node list; 222 unsigned int nr_cached; 223 unsigned int max_cached; 224 size_t elem_size; 225 }; 226 227 struct io_ring_ctx { 228 /* const or read-mostly hot data */ 229 struct { 230 unsigned int flags; 231 unsigned int drain_next: 1; 232 unsigned int restricted: 1; 233 unsigned int off_timeout_used: 1; 234 unsigned int drain_active: 1; 235 unsigned int has_evfd: 1; 236 /* all CQEs should be posted only by the submitter task */ 237 unsigned int task_complete: 1; 238 unsigned int lockless_cq: 1; 239 unsigned int syscall_iopoll: 1; 240 unsigned int poll_activated: 1; 241 unsigned int drain_disabled: 1; 242 unsigned int compat: 1; 243 244 struct task_struct *submitter_task; 245 struct io_rings *rings; 246 struct percpu_ref refs; 247 248 enum task_work_notify_mode notify_method; 249 } ____cacheline_aligned_in_smp; 250 251 /* submission data */ 252 struct { 253 struct mutex uring_lock; 254 255 /* 256 * Ring buffer of indices into array of io_uring_sqe, which is 257 * mmapped by the application using the IORING_OFF_SQES offset. 258 * 259 * This indirection could e.g. be used to assign fixed 260 * io_uring_sqe entries to operations and only submit them to 261 * the queue when needed. 262 * 263 * The kernel modifies neither the indices array nor the entries 264 * array. 265 */ 266 u32 *sq_array; 267 struct io_uring_sqe *sq_sqes; 268 unsigned cached_sq_head; 269 unsigned sq_entries; 270 271 /* 272 * Fixed resources fast path, should be accessed only under 273 * uring_lock, and updated through io_uring_register(2) 274 */ 275 struct io_rsrc_node *rsrc_node; 276 atomic_t cancel_seq; 277 struct io_file_table file_table; 278 unsigned nr_user_files; 279 unsigned nr_user_bufs; 280 struct io_mapped_ubuf **user_bufs; 281 282 struct io_submit_state submit_state; 283 284 struct io_buffer_list *io_bl; 285 struct xarray io_bl_xa; 286 287 struct io_hash_table cancel_table_locked; 288 struct io_alloc_cache apoll_cache; 289 struct io_alloc_cache netmsg_cache; 290 291 /* 292 * ->iopoll_list is protected by the ctx->uring_lock for 293 * io_uring instances that don't use IORING_SETUP_SQPOLL. 294 * For SQPOLL, only the single threaded io_sq_thread() will 295 * manipulate the list, hence no extra locking is needed there. 296 */ 297 struct io_wq_work_list iopoll_list; 298 bool poll_multi_queue; 299 300 /* 301 * Any cancelable uring_cmd is added to this list in 302 * ->uring_cmd() by io_uring_cmd_insert_cancelable() 303 */ 304 struct hlist_head cancelable_uring_cmd; 305 } ____cacheline_aligned_in_smp; 306 307 struct { 308 /* 309 * We cache a range of free CQEs we can use, once exhausted it 310 * should go through a slower range setup, see __io_get_cqe() 311 */ 312 struct io_uring_cqe *cqe_cached; 313 struct io_uring_cqe *cqe_sentinel; 314 315 unsigned cached_cq_tail; 316 unsigned cq_entries; 317 struct io_ev_fd __rcu *io_ev_fd; 318 unsigned cq_extra; 319 } ____cacheline_aligned_in_smp; 320 321 /* 322 * task_work and async notification delivery cacheline. Expected to 323 * regularly bounce b/w CPUs. 324 */ 325 struct { 326 struct llist_head work_llist; 327 unsigned long check_cq; 328 atomic_t cq_wait_nr; 329 atomic_t cq_timeouts; 330 struct wait_queue_head cq_wait; 331 } ____cacheline_aligned_in_smp; 332 333 /* timeouts */ 334 struct { 335 spinlock_t timeout_lock; 336 struct list_head timeout_list; 337 struct list_head ltimeout_list; 338 unsigned cq_last_tm_flush; 339 } ____cacheline_aligned_in_smp; 340 341 struct io_uring_cqe completion_cqes[16]; 342 343 spinlock_t completion_lock; 344 345 /* IRQ completion list, under ->completion_lock */ 346 struct io_wq_work_list locked_free_list; 347 unsigned int locked_free_nr; 348 349 struct list_head io_buffers_comp; 350 struct list_head cq_overflow_list; 351 struct io_hash_table cancel_table; 352 353 struct hlist_head waitid_list; 354 355 #ifdef CONFIG_FUTEX 356 struct hlist_head futex_list; 357 struct io_alloc_cache futex_cache; 358 #endif 359 360 const struct cred *sq_creds; /* cred used for __io_sq_thread() */ 361 struct io_sq_data *sq_data; /* if using sq thread polling */ 362 363 struct wait_queue_head sqo_sq_wait; 364 struct list_head sqd_list; 365 366 unsigned int file_alloc_start; 367 unsigned int file_alloc_end; 368 369 struct xarray personalities; 370 u32 pers_next; 371 372 struct list_head io_buffers_cache; 373 374 /* deferred free list, protected by ->uring_lock */ 375 struct hlist_head io_buf_list; 376 377 /* Keep this last, we don't need it for the fast path */ 378 struct wait_queue_head poll_wq; 379 struct io_restriction restrictions; 380 381 /* slow path rsrc auxilary data, used by update/register */ 382 struct io_mapped_ubuf *dummy_ubuf; 383 struct io_rsrc_data *file_data; 384 struct io_rsrc_data *buf_data; 385 386 /* protected by ->uring_lock */ 387 struct list_head rsrc_ref_list; 388 struct io_alloc_cache rsrc_node_cache; 389 struct wait_queue_head rsrc_quiesce_wq; 390 unsigned rsrc_quiesce; 391 392 /* hashed buffered write serialization */ 393 struct io_wq_hash *hash_map; 394 395 /* Only used for accounting purposes */ 396 struct user_struct *user; 397 struct mm_struct *mm_account; 398 399 /* ctx exit and cancelation */ 400 struct llist_head fallback_llist; 401 struct delayed_work fallback_work; 402 struct work_struct exit_work; 403 struct list_head tctx_list; 404 struct completion ref_comp; 405 406 /* io-wq management, e.g. thread count */ 407 u32 iowq_limits[2]; 408 bool iowq_limits_set; 409 410 struct callback_head poll_wq_task_work; 411 struct list_head defer_list; 412 unsigned sq_thread_idle; 413 /* protected by ->completion_lock */ 414 unsigned evfd_last_cq_tail; 415 416 /* 417 * If IORING_SETUP_NO_MMAP is used, then the below holds 418 * the gup'ed pages for the two rings, and the sqes. 419 */ 420 unsigned short n_ring_pages; 421 unsigned short n_sqe_pages; 422 struct page **ring_pages; 423 struct page **sqe_pages; 424 }; 425 426 struct io_tw_state { 427 /* ->uring_lock is taken, callbacks can use io_tw_lock to lock it */ 428 bool locked; 429 }; 430 431 enum { 432 REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT, 433 REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT, 434 REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT, 435 REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT, 436 REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT, 437 REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT, 438 REQ_F_CQE_SKIP_BIT = IOSQE_CQE_SKIP_SUCCESS_BIT, 439 440 /* first byte is taken by user flags, shift it to not overlap */ 441 REQ_F_FAIL_BIT = 8, 442 REQ_F_INFLIGHT_BIT, 443 REQ_F_CUR_POS_BIT, 444 REQ_F_NOWAIT_BIT, 445 REQ_F_LINK_TIMEOUT_BIT, 446 REQ_F_NEED_CLEANUP_BIT, 447 REQ_F_POLLED_BIT, 448 REQ_F_BUFFER_SELECTED_BIT, 449 REQ_F_BUFFER_RING_BIT, 450 REQ_F_REISSUE_BIT, 451 REQ_F_CREDS_BIT, 452 REQ_F_REFCOUNT_BIT, 453 REQ_F_ARM_LTIMEOUT_BIT, 454 REQ_F_ASYNC_DATA_BIT, 455 REQ_F_SKIP_LINK_CQES_BIT, 456 REQ_F_SINGLE_POLL_BIT, 457 REQ_F_DOUBLE_POLL_BIT, 458 REQ_F_PARTIAL_IO_BIT, 459 REQ_F_APOLL_MULTISHOT_BIT, 460 REQ_F_CLEAR_POLLIN_BIT, 461 REQ_F_HASH_LOCKED_BIT, 462 /* keep async read/write and isreg together and in order */ 463 REQ_F_SUPPORT_NOWAIT_BIT, 464 REQ_F_ISREG_BIT, 465 REQ_F_POLL_NO_LAZY_BIT, 466 467 /* not a real bit, just to check we're not overflowing the space */ 468 __REQ_F_LAST_BIT, 469 }; 470 471 enum { 472 /* ctx owns file */ 473 REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT), 474 /* drain existing IO first */ 475 REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT), 476 /* linked sqes */ 477 REQ_F_LINK = BIT(REQ_F_LINK_BIT), 478 /* doesn't sever on completion < 0 */ 479 REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT), 480 /* IOSQE_ASYNC */ 481 REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT), 482 /* IOSQE_BUFFER_SELECT */ 483 REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT), 484 /* IOSQE_CQE_SKIP_SUCCESS */ 485 REQ_F_CQE_SKIP = BIT(REQ_F_CQE_SKIP_BIT), 486 487 /* fail rest of links */ 488 REQ_F_FAIL = BIT(REQ_F_FAIL_BIT), 489 /* on inflight list, should be cancelled and waited on exit reliably */ 490 REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT), 491 /* read/write uses file position */ 492 REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT), 493 /* must not punt to workers */ 494 REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT), 495 /* has or had linked timeout */ 496 REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT), 497 /* needs cleanup */ 498 REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT), 499 /* already went through poll handler */ 500 REQ_F_POLLED = BIT(REQ_F_POLLED_BIT), 501 /* buffer already selected */ 502 REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT), 503 /* buffer selected from ring, needs commit */ 504 REQ_F_BUFFER_RING = BIT(REQ_F_BUFFER_RING_BIT), 505 /* caller should reissue async */ 506 REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT), 507 /* supports async reads/writes */ 508 REQ_F_SUPPORT_NOWAIT = BIT(REQ_F_SUPPORT_NOWAIT_BIT), 509 /* regular file */ 510 REQ_F_ISREG = BIT(REQ_F_ISREG_BIT), 511 /* has creds assigned */ 512 REQ_F_CREDS = BIT(REQ_F_CREDS_BIT), 513 /* skip refcounting if not set */ 514 REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT), 515 /* there is a linked timeout that has to be armed */ 516 REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT), 517 /* ->async_data allocated */ 518 REQ_F_ASYNC_DATA = BIT(REQ_F_ASYNC_DATA_BIT), 519 /* don't post CQEs while failing linked requests */ 520 REQ_F_SKIP_LINK_CQES = BIT(REQ_F_SKIP_LINK_CQES_BIT), 521 /* single poll may be active */ 522 REQ_F_SINGLE_POLL = BIT(REQ_F_SINGLE_POLL_BIT), 523 /* double poll may active */ 524 REQ_F_DOUBLE_POLL = BIT(REQ_F_DOUBLE_POLL_BIT), 525 /* request has already done partial IO */ 526 REQ_F_PARTIAL_IO = BIT(REQ_F_PARTIAL_IO_BIT), 527 /* fast poll multishot mode */ 528 REQ_F_APOLL_MULTISHOT = BIT(REQ_F_APOLL_MULTISHOT_BIT), 529 /* recvmsg special flag, clear EPOLLIN */ 530 REQ_F_CLEAR_POLLIN = BIT(REQ_F_CLEAR_POLLIN_BIT), 531 /* hashed into ->cancel_hash_locked, protected by ->uring_lock */ 532 REQ_F_HASH_LOCKED = BIT(REQ_F_HASH_LOCKED_BIT), 533 /* don't use lazy poll wake for this request */ 534 REQ_F_POLL_NO_LAZY = BIT(REQ_F_POLL_NO_LAZY_BIT), 535 }; 536 537 typedef void (*io_req_tw_func_t)(struct io_kiocb *req, struct io_tw_state *ts); 538 539 struct io_task_work { 540 struct llist_node node; 541 io_req_tw_func_t func; 542 }; 543 544 struct io_cqe { 545 __u64 user_data; 546 __s32 res; 547 /* fd initially, then cflags for completion */ 548 union { 549 __u32 flags; 550 int fd; 551 }; 552 }; 553 554 /* 555 * Each request type overlays its private data structure on top of this one. 556 * They must not exceed this one in size. 557 */ 558 struct io_cmd_data { 559 struct file *file; 560 /* each command gets 56 bytes of data */ 561 __u8 data[56]; 562 }; 563 564 static inline void io_kiocb_cmd_sz_check(size_t cmd_sz) 565 { 566 BUILD_BUG_ON(cmd_sz > sizeof(struct io_cmd_data)); 567 } 568 #define io_kiocb_to_cmd(req, cmd_type) ( \ 569 io_kiocb_cmd_sz_check(sizeof(cmd_type)) , \ 570 ((cmd_type *)&(req)->cmd) \ 571 ) 572 #define cmd_to_io_kiocb(ptr) ((struct io_kiocb *) ptr) 573 574 struct io_kiocb { 575 union { 576 /* 577 * NOTE! Each of the io_kiocb union members has the file pointer 578 * as the first entry in their struct definition. So you can 579 * access the file pointer through any of the sub-structs, 580 * or directly as just 'file' in this struct. 581 */ 582 struct file *file; 583 struct io_cmd_data cmd; 584 }; 585 586 u8 opcode; 587 /* polled IO has completed */ 588 u8 iopoll_completed; 589 /* 590 * Can be either a fixed buffer index, or used with provided buffers. 591 * For the latter, before issue it points to the buffer group ID, 592 * and after selection it points to the buffer ID itself. 593 */ 594 u16 buf_index; 595 unsigned int flags; 596 597 struct io_cqe cqe; 598 599 struct io_ring_ctx *ctx; 600 struct task_struct *task; 601 602 struct io_rsrc_node *rsrc_node; 603 604 union { 605 /* store used ubuf, so we can prevent reloading */ 606 struct io_mapped_ubuf *imu; 607 608 /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */ 609 struct io_buffer *kbuf; 610 611 /* 612 * stores buffer ID for ring provided buffers, valid IFF 613 * REQ_F_BUFFER_RING is set. 614 */ 615 struct io_buffer_list *buf_list; 616 }; 617 618 union { 619 /* used by request caches, completion batching and iopoll */ 620 struct io_wq_work_node comp_list; 621 /* cache ->apoll->events */ 622 __poll_t apoll_events; 623 }; 624 atomic_t refs; 625 atomic_t poll_refs; 626 struct io_task_work io_task_work; 627 unsigned nr_tw; 628 /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */ 629 struct hlist_node hash_node; 630 /* internal polling, see IORING_FEAT_FAST_POLL */ 631 struct async_poll *apoll; 632 /* opcode allocated if it needs to store data for async defer */ 633 void *async_data; 634 /* linked requests, IFF REQ_F_HARDLINK or REQ_F_LINK are set */ 635 struct io_kiocb *link; 636 /* custom credentials, valid IFF REQ_F_CREDS is set */ 637 const struct cred *creds; 638 struct io_wq_work work; 639 640 struct { 641 u64 extra1; 642 u64 extra2; 643 } big_cqe; 644 }; 645 646 struct io_overflow_cqe { 647 struct list_head list; 648 struct io_uring_cqe cqe; 649 }; 650 651 #endif 652