1 #ifndef IOU_CORE_H 2 #define IOU_CORE_H 3 4 #include <linux/errno.h> 5 #include <linux/lockdep.h> 6 #include <linux/resume_user_mode.h> 7 #include <linux/kasan.h> 8 #include <linux/poll.h> 9 #include <linux/io_uring_types.h> 10 #include <uapi/linux/eventpoll.h> 11 #include "alloc_cache.h" 12 #include "io-wq.h" 13 #include "slist.h" 14 #include "opdef.h" 15 16 #ifndef CREATE_TRACE_POINTS 17 #include <trace/events/io_uring.h> 18 #endif 19 20 struct io_rings_layout { 21 /* size of CQ + headers + SQ offset array */ 22 size_t rings_size; 23 size_t sq_size; 24 25 size_t sq_array_offset; 26 }; 27 28 struct io_ctx_config { 29 struct io_uring_params p; 30 struct io_rings_layout layout; 31 struct io_uring_params __user *uptr; 32 }; 33 34 #define IORING_FEAT_FLAGS (IORING_FEAT_SINGLE_MMAP |\ 35 IORING_FEAT_NODROP |\ 36 IORING_FEAT_SUBMIT_STABLE |\ 37 IORING_FEAT_RW_CUR_POS |\ 38 IORING_FEAT_CUR_PERSONALITY |\ 39 IORING_FEAT_FAST_POLL |\ 40 IORING_FEAT_POLL_32BITS |\ 41 IORING_FEAT_SQPOLL_NONFIXED |\ 42 IORING_FEAT_EXT_ARG |\ 43 IORING_FEAT_NATIVE_WORKERS |\ 44 IORING_FEAT_RSRC_TAGS |\ 45 IORING_FEAT_CQE_SKIP |\ 46 IORING_FEAT_LINKED_FILE |\ 47 IORING_FEAT_REG_REG_RING |\ 48 IORING_FEAT_RECVSEND_BUNDLE |\ 49 IORING_FEAT_MIN_TIMEOUT |\ 50 IORING_FEAT_RW_ATTR |\ 51 IORING_FEAT_NO_IOWAIT) 52 53 #define IORING_SETUP_FLAGS (IORING_SETUP_IOPOLL |\ 54 IORING_SETUP_SQPOLL |\ 55 IORING_SETUP_SQ_AFF |\ 56 IORING_SETUP_CQSIZE |\ 57 IORING_SETUP_CLAMP |\ 58 IORING_SETUP_ATTACH_WQ |\ 59 IORING_SETUP_R_DISABLED |\ 60 IORING_SETUP_SUBMIT_ALL |\ 61 IORING_SETUP_COOP_TASKRUN |\ 62 IORING_SETUP_TASKRUN_FLAG |\ 63 IORING_SETUP_SQE128 |\ 64 IORING_SETUP_CQE32 |\ 65 IORING_SETUP_SINGLE_ISSUER |\ 66 IORING_SETUP_DEFER_TASKRUN |\ 67 IORING_SETUP_NO_MMAP |\ 68 IORING_SETUP_REGISTERED_FD_ONLY |\ 69 IORING_SETUP_NO_SQARRAY |\ 70 IORING_SETUP_HYBRID_IOPOLL |\ 71 IORING_SETUP_CQE_MIXED |\ 72 IORING_SETUP_SQE_MIXED) 73 74 #define IORING_ENTER_FLAGS (IORING_ENTER_GETEVENTS |\ 75 IORING_ENTER_SQ_WAKEUP |\ 76 IORING_ENTER_SQ_WAIT |\ 77 IORING_ENTER_EXT_ARG |\ 78 IORING_ENTER_REGISTERED_RING |\ 79 IORING_ENTER_ABS_TIMER |\ 80 IORING_ENTER_EXT_ARG_REG |\ 81 IORING_ENTER_NO_IOWAIT) 82 83 84 #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE |\ 85 IOSQE_IO_DRAIN |\ 86 IOSQE_IO_LINK |\ 87 IOSQE_IO_HARDLINK |\ 88 IOSQE_ASYNC |\ 89 IOSQE_BUFFER_SELECT |\ 90 IOSQE_CQE_SKIP_SUCCESS) 91 92 enum { 93 IOU_COMPLETE = 0, 94 95 IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED, 96 97 /* 98 * The request has more work to do and should be retried. io_uring will 99 * attempt to wait on the file for eligible opcodes, but otherwise 100 * it'll be handed to iowq for blocking execution. It works for normal 101 * requests as well as for the multi shot mode. 102 */ 103 IOU_RETRY = -EAGAIN, 104 105 /* 106 * Requeue the task_work to restart operations on this request. The 107 * actual value isn't important, should just be not an otherwise 108 * valid error code, yet less than -MAX_ERRNO and valid internally. 109 */ 110 IOU_REQUEUE = -3072, 111 }; 112 113 struct io_defer_entry { 114 struct list_head list; 115 struct io_kiocb *req; 116 }; 117 118 struct io_wait_queue { 119 struct wait_queue_entry wq; 120 struct io_ring_ctx *ctx; 121 unsigned cq_tail; 122 unsigned cq_min_tail; 123 unsigned nr_timeouts; 124 int hit_timeout; 125 ktime_t min_timeout; 126 ktime_t timeout; 127 struct hrtimer t; 128 129 #ifdef CONFIG_NET_RX_BUSY_POLL 130 ktime_t napi_busy_poll_dt; 131 bool napi_prefer_busy_poll; 132 #endif 133 }; 134 135 static inline bool io_should_wake(struct io_wait_queue *iowq) 136 { 137 struct io_ring_ctx *ctx = iowq->ctx; 138 int dist = READ_ONCE(ctx->rings->cq.tail) - (int) iowq->cq_tail; 139 140 /* 141 * Wake up if we have enough events, or if a timeout occurred since we 142 * started waiting. For timeouts, we always want to return to userspace, 143 * regardless of event count. 144 */ 145 return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; 146 } 147 148 #define IORING_MAX_ENTRIES 32768 149 #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) 150 151 int io_prepare_config(struct io_ctx_config *config); 152 153 bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow, bool cqe32); 154 int io_run_task_work_sig(struct io_ring_ctx *ctx); 155 int io_run_local_work(struct io_ring_ctx *ctx, int min_events, int max_events); 156 void io_req_defer_failed(struct io_kiocb *req, s32 res); 157 bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); 158 void io_add_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); 159 bool io_req_post_cqe(struct io_kiocb *req, s32 res, u32 cflags); 160 bool io_req_post_cqe32(struct io_kiocb *req, struct io_uring_cqe src_cqe[2]); 161 void __io_commit_cqring_flush(struct io_ring_ctx *ctx); 162 163 unsigned io_linked_nr(struct io_kiocb *req); 164 void io_req_track_inflight(struct io_kiocb *req); 165 struct file *io_file_get_normal(struct io_kiocb *req, int fd); 166 struct file *io_file_get_fixed(struct io_kiocb *req, int fd, 167 unsigned issue_flags); 168 169 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags); 170 void io_req_task_work_add_remote(struct io_kiocb *req, unsigned flags); 171 void io_req_task_queue(struct io_kiocb *req); 172 void io_req_task_complete(struct io_tw_req tw_req, io_tw_token_t tw); 173 void io_req_task_queue_fail(struct io_kiocb *req, int ret); 174 void io_req_task_submit(struct io_tw_req tw_req, io_tw_token_t tw); 175 struct llist_node *io_handle_tw_list(struct llist_node *node, unsigned int *count, unsigned int max_entries); 176 struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, unsigned int max_entries, unsigned int *count); 177 void tctx_task_work(struct callback_head *cb); 178 __cold void io_uring_drop_tctx_refs(struct task_struct *task); 179 180 int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file, 181 int start, int end); 182 void io_req_queue_iowq(struct io_kiocb *req); 183 184 int io_poll_issue(struct io_kiocb *req, io_tw_token_t tw); 185 int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr); 186 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin); 187 __cold void io_iopoll_try_reap_events(struct io_ring_ctx *ctx); 188 void __io_submit_flush_completions(struct io_ring_ctx *ctx); 189 190 struct io_wq_work *io_wq_free_work(struct io_wq_work *work); 191 void io_wq_submit_work(struct io_wq_work *work); 192 193 void io_free_req(struct io_kiocb *req); 194 void io_queue_next(struct io_kiocb *req); 195 void io_task_refs_refill(struct io_uring_task *tctx); 196 bool __io_alloc_req_refill(struct io_ring_ctx *ctx); 197 198 void io_activate_pollwq(struct io_ring_ctx *ctx); 199 200 static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx) 201 { 202 #if defined(CONFIG_PROVE_LOCKING) 203 lockdep_assert(in_task()); 204 205 if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) 206 lockdep_assert_held(&ctx->uring_lock); 207 208 if (ctx->flags & IORING_SETUP_IOPOLL) { 209 lockdep_assert_held(&ctx->uring_lock); 210 } else if (!ctx->task_complete) { 211 lockdep_assert_held(&ctx->completion_lock); 212 } else if (ctx->submitter_task) { 213 /* 214 * ->submitter_task may be NULL and we can still post a CQE, 215 * if the ring has been setup with IORING_SETUP_R_DISABLED. 216 * Not from an SQE, as those cannot be submitted, but via 217 * updating tagged resources. 218 */ 219 if (!percpu_ref_is_dying(&ctx->refs)) 220 lockdep_assert(current == ctx->submitter_task); 221 } 222 #endif 223 } 224 225 static inline bool io_is_compat(struct io_ring_ctx *ctx) 226 { 227 return IS_ENABLED(CONFIG_COMPAT) && unlikely(ctx->compat); 228 } 229 230 static inline void io_req_task_work_add(struct io_kiocb *req) 231 { 232 __io_req_task_work_add(req, 0); 233 } 234 235 static inline void io_submit_flush_completions(struct io_ring_ctx *ctx) 236 { 237 if (!wq_list_empty(&ctx->submit_state.compl_reqs) || 238 ctx->submit_state.cq_flush) 239 __io_submit_flush_completions(ctx); 240 } 241 242 #define io_for_each_link(pos, head) \ 243 for (pos = (head); pos; pos = pos->link) 244 245 static inline bool io_get_cqe_overflow(struct io_ring_ctx *ctx, 246 struct io_uring_cqe **ret, 247 bool overflow, bool cqe32) 248 { 249 io_lockdep_assert_cq_locked(ctx); 250 251 if (unlikely(ctx->cqe_sentinel - ctx->cqe_cached < (cqe32 + 1))) { 252 if (unlikely(!io_cqe_cache_refill(ctx, overflow, cqe32))) 253 return false; 254 } 255 *ret = ctx->cqe_cached; 256 ctx->cached_cq_tail++; 257 ctx->cqe_cached++; 258 if (ctx->flags & IORING_SETUP_CQE32) { 259 ctx->cqe_cached++; 260 } else if (cqe32 && ctx->flags & IORING_SETUP_CQE_MIXED) { 261 ctx->cqe_cached++; 262 ctx->cached_cq_tail++; 263 } 264 WARN_ON_ONCE(ctx->cqe_cached > ctx->cqe_sentinel); 265 return true; 266 } 267 268 static inline bool io_get_cqe(struct io_ring_ctx *ctx, struct io_uring_cqe **ret, 269 bool cqe32) 270 { 271 return io_get_cqe_overflow(ctx, ret, false, cqe32); 272 } 273 274 static inline bool io_defer_get_uncommited_cqe(struct io_ring_ctx *ctx, 275 struct io_uring_cqe **cqe_ret) 276 { 277 io_lockdep_assert_cq_locked(ctx); 278 279 ctx->submit_state.cq_flush = true; 280 return io_get_cqe(ctx, cqe_ret, ctx->flags & IORING_SETUP_CQE_MIXED); 281 } 282 283 static __always_inline bool io_fill_cqe_req(struct io_ring_ctx *ctx, 284 struct io_kiocb *req) 285 { 286 bool is_cqe32 = req->cqe.flags & IORING_CQE_F_32; 287 struct io_uring_cqe *cqe; 288 289 /* 290 * If we can't get a cq entry, userspace overflowed the submission 291 * (by quite a lot). 292 */ 293 if (unlikely(!io_get_cqe(ctx, &cqe, is_cqe32))) 294 return false; 295 296 memcpy(cqe, &req->cqe, sizeof(*cqe)); 297 if (ctx->flags & IORING_SETUP_CQE32 || is_cqe32) { 298 memcpy(cqe->big_cqe, &req->big_cqe, sizeof(*cqe)); 299 memset(&req->big_cqe, 0, sizeof(req->big_cqe)); 300 } 301 302 if (trace_io_uring_complete_enabled()) 303 trace_io_uring_complete(req->ctx, req, cqe); 304 return true; 305 } 306 307 static inline void req_set_fail(struct io_kiocb *req) 308 { 309 req->flags |= REQ_F_FAIL; 310 if (req->flags & REQ_F_CQE_SKIP) { 311 req->flags &= ~REQ_F_CQE_SKIP; 312 req->flags |= REQ_F_SKIP_LINK_CQES; 313 } 314 } 315 316 static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags) 317 { 318 req->cqe.res = res; 319 req->cqe.flags = cflags; 320 } 321 322 static inline u32 ctx_cqe32_flags(struct io_ring_ctx *ctx) 323 { 324 if (ctx->flags & IORING_SETUP_CQE_MIXED) 325 return IORING_CQE_F_32; 326 return 0; 327 } 328 329 static inline void io_req_set_res32(struct io_kiocb *req, s32 res, u32 cflags, 330 __u64 extra1, __u64 extra2) 331 { 332 req->cqe.res = res; 333 req->cqe.flags = cflags | ctx_cqe32_flags(req->ctx); 334 req->big_cqe.extra1 = extra1; 335 req->big_cqe.extra2 = extra2; 336 } 337 338 static inline void *io_uring_alloc_async_data(struct io_alloc_cache *cache, 339 struct io_kiocb *req) 340 { 341 if (cache) { 342 req->async_data = io_cache_alloc(cache, GFP_KERNEL); 343 } else { 344 const struct io_issue_def *def = &io_issue_defs[req->opcode]; 345 346 WARN_ON_ONCE(!def->async_size); 347 req->async_data = kmalloc(def->async_size, GFP_KERNEL); 348 } 349 if (req->async_data) 350 req->flags |= REQ_F_ASYNC_DATA; 351 return req->async_data; 352 } 353 354 static inline bool req_has_async_data(struct io_kiocb *req) 355 { 356 return req->flags & REQ_F_ASYNC_DATA; 357 } 358 359 static inline void io_req_async_data_clear(struct io_kiocb *req, 360 io_req_flags_t extra_flags) 361 { 362 req->flags &= ~(REQ_F_ASYNC_DATA|extra_flags); 363 req->async_data = NULL; 364 } 365 366 static inline void io_req_async_data_free(struct io_kiocb *req) 367 { 368 kfree(req->async_data); 369 io_req_async_data_clear(req, 0); 370 } 371 372 static inline void io_put_file(struct io_kiocb *req) 373 { 374 if (!(req->flags & REQ_F_FIXED_FILE) && req->file) 375 fput(req->file); 376 } 377 378 static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx, 379 unsigned issue_flags) 380 { 381 lockdep_assert_held(&ctx->uring_lock); 382 if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) 383 mutex_unlock(&ctx->uring_lock); 384 } 385 386 static inline void io_ring_submit_lock(struct io_ring_ctx *ctx, 387 unsigned issue_flags) 388 { 389 /* 390 * "Normal" inline submissions always hold the uring_lock, since we 391 * grab it from the system call. Same is true for the SQPOLL offload. 392 * The only exception is when we've detached the request and issue it 393 * from an async worker thread, grab the lock for that case. 394 */ 395 if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) 396 mutex_lock(&ctx->uring_lock); 397 lockdep_assert_held(&ctx->uring_lock); 398 } 399 400 static inline void io_commit_cqring(struct io_ring_ctx *ctx) 401 { 402 /* order cqe stores with ring update */ 403 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); 404 } 405 406 static inline void __io_wq_wake(struct wait_queue_head *wq) 407 { 408 /* 409 * 410 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter 411 * set in the mask so that if we recurse back into our own poll 412 * waitqueue handlers, we know we have a dependency between eventfd or 413 * epoll and should terminate multishot poll at that point. 414 */ 415 if (wq_has_sleeper(wq)) 416 __wake_up(wq, TASK_NORMAL, 0, poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 417 } 418 419 static inline void io_poll_wq_wake(struct io_ring_ctx *ctx) 420 { 421 __io_wq_wake(&ctx->poll_wq); 422 } 423 424 static inline void io_cqring_wake(struct io_ring_ctx *ctx) 425 { 426 /* 427 * Trigger waitqueue handler on all waiters on our waitqueue. This 428 * won't necessarily wake up all the tasks, io_should_wake() will make 429 * that decision. 430 */ 431 432 __io_wq_wake(&ctx->cq_wait); 433 } 434 435 static inline bool io_sqring_full(struct io_ring_ctx *ctx) 436 { 437 struct io_rings *r = ctx->rings; 438 439 /* 440 * SQPOLL must use the actual sqring head, as using the cached_sq_head 441 * is race prone if the SQPOLL thread has grabbed entries but not yet 442 * committed them to the ring. For !SQPOLL, this doesn't matter, but 443 * since this helper is just used for SQPOLL sqring waits (or POLLOUT), 444 * just read the actual sqring head unconditionally. 445 */ 446 return READ_ONCE(r->sq.tail) - READ_ONCE(r->sq.head) == ctx->sq_entries; 447 } 448 449 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) 450 { 451 struct io_rings *rings = ctx->rings; 452 unsigned int entries; 453 454 /* make sure SQ entry isn't read before tail */ 455 entries = smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; 456 return min(entries, ctx->sq_entries); 457 } 458 459 static inline int io_run_task_work(void) 460 { 461 bool ret = false; 462 463 /* 464 * Always check-and-clear the task_work notification signal. With how 465 * signaling works for task_work, we can find it set with nothing to 466 * run. We need to clear it for that case, like get_signal() does. 467 */ 468 if (test_thread_flag(TIF_NOTIFY_SIGNAL)) 469 clear_notify_signal(); 470 /* 471 * PF_IO_WORKER never returns to userspace, so check here if we have 472 * notify work that needs processing. 473 */ 474 if (current->flags & PF_IO_WORKER) { 475 if (test_thread_flag(TIF_NOTIFY_RESUME)) { 476 __set_current_state(TASK_RUNNING); 477 resume_user_mode_work(NULL); 478 } 479 if (current->io_uring) { 480 unsigned int count = 0; 481 482 __set_current_state(TASK_RUNNING); 483 tctx_task_work_run(current->io_uring, UINT_MAX, &count); 484 if (count) 485 ret = true; 486 } 487 } 488 if (task_work_pending(current)) { 489 __set_current_state(TASK_RUNNING); 490 task_work_run(); 491 ret = true; 492 } 493 494 return ret; 495 } 496 497 static inline bool io_local_work_pending(struct io_ring_ctx *ctx) 498 { 499 return !llist_empty(&ctx->work_llist) || !llist_empty(&ctx->retry_llist); 500 } 501 502 static inline bool io_task_work_pending(struct io_ring_ctx *ctx) 503 { 504 return task_work_pending(current) || io_local_work_pending(ctx); 505 } 506 507 static inline void io_tw_lock(struct io_ring_ctx *ctx, io_tw_token_t tw) 508 { 509 lockdep_assert_held(&ctx->uring_lock); 510 } 511 512 /* 513 * Don't complete immediately but use deferred completion infrastructure. 514 * Protected by ->uring_lock and can only be used either with 515 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex. 516 */ 517 static inline void io_req_complete_defer(struct io_kiocb *req) 518 __must_hold(&req->ctx->uring_lock) 519 { 520 struct io_submit_state *state = &req->ctx->submit_state; 521 522 lockdep_assert_held(&req->ctx->uring_lock); 523 524 wq_list_add_tail(&req->comp_list, &state->compl_reqs); 525 } 526 527 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx) 528 { 529 if (unlikely(ctx->off_timeout_used || 530 ctx->has_evfd || ctx->poll_activated)) 531 __io_commit_cqring_flush(ctx); 532 } 533 534 static inline void io_get_task_refs(int nr) 535 { 536 struct io_uring_task *tctx = current->io_uring; 537 538 tctx->cached_refs -= nr; 539 if (unlikely(tctx->cached_refs < 0)) 540 io_task_refs_refill(tctx); 541 } 542 543 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx) 544 { 545 return !ctx->submit_state.free_list.next; 546 } 547 548 extern struct kmem_cache *req_cachep; 549 550 static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx) 551 { 552 struct io_kiocb *req; 553 554 req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list); 555 wq_stack_extract(&ctx->submit_state.free_list); 556 return req; 557 } 558 559 static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req) 560 { 561 if (unlikely(io_req_cache_empty(ctx))) { 562 if (!__io_alloc_req_refill(ctx)) 563 return false; 564 } 565 *req = io_extract_req(ctx); 566 return true; 567 } 568 569 static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx) 570 { 571 return likely(ctx->submitter_task == current); 572 } 573 574 static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) 575 { 576 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || 577 ctx->submitter_task == current); 578 } 579 580 static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) 581 { 582 io_req_set_res(req, res, 0); 583 req->io_task_work.func = io_req_task_complete; 584 io_req_task_work_add(req); 585 } 586 587 static inline bool io_file_can_poll(struct io_kiocb *req) 588 { 589 if (req->flags & REQ_F_CAN_POLL) 590 return true; 591 if (req->file && file_can_poll(req->file)) { 592 req->flags |= REQ_F_CAN_POLL; 593 return true; 594 } 595 return false; 596 } 597 598 static inline ktime_t io_get_time(struct io_ring_ctx *ctx) 599 { 600 if (ctx->clockid == CLOCK_MONOTONIC) 601 return ktime_get(); 602 603 return ktime_get_with_offset(ctx->clock_offset); 604 } 605 606 enum { 607 IO_CHECK_CQ_OVERFLOW_BIT, 608 IO_CHECK_CQ_DROPPED_BIT, 609 }; 610 611 static inline bool io_has_work(struct io_ring_ctx *ctx) 612 { 613 return test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq) || 614 io_local_work_pending(ctx); 615 } 616 #endif 617