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 "io-wq.h" 12#include "slist.h" 13#include "filetable.h" 14 15#ifndef CREATE_TRACE_POINTS 16#include <trace/events/io_uring.h> 17#endif 18 19enum { 20 IOU_OK = 0, 21 IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED, 22 23 /* 24 * Requeue the task_work to restart operations on this request. The 25 * actual value isn't important, should just be not an otherwise 26 * valid error code, yet less than -MAX_ERRNO and valid internally. 27 */ 28 IOU_REQUEUE = -3072, 29 30 /* 31 * Intended only when both IO_URING_F_MULTISHOT is passed 32 * to indicate to the poll runner that multishot should be 33 * removed and the result is set on req->cqe.res. 34 */ 35 IOU_STOP_MULTISHOT = -ECANCELED, 36}; 37 38struct io_wait_queue { 39 struct wait_queue_entry wq; 40 struct io_ring_ctx *ctx; 41 unsigned cq_tail; 42 unsigned nr_timeouts; 43 ktime_t timeout; 44 45#ifdef CONFIG_NET_RX_BUSY_POLL 46 unsigned int napi_busy_poll_to; 47 bool napi_prefer_busy_poll; 48#endif 49}; 50 51static inline bool io_should_wake(struct io_wait_queue *iowq) 52{ 53 struct io_ring_ctx *ctx = iowq->ctx; 54 int dist = READ_ONCE(ctx->rings->cq.tail) - (int) iowq->cq_tail; 55 56 /* 57 * Wake up if we have enough events, or if a timeout occurred since we 58 * started waiting. For timeouts, we always want to return to userspace, 59 * regardless of event count. 60 */ 61 return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; 62} 63 64bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow); 65void io_req_cqe_overflow(struct io_kiocb *req); 66int io_run_task_work_sig(struct io_ring_ctx *ctx); 67void io_req_defer_failed(struct io_kiocb *req, s32 res); 68void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags); 69bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); 70bool io_fill_cqe_req_aux(struct io_kiocb *req, bool defer, s32 res, u32 cflags); 71void __io_commit_cqring_flush(struct io_ring_ctx *ctx); 72 73struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages); 74 75struct file *io_file_get_normal(struct io_kiocb *req, int fd); 76struct file *io_file_get_fixed(struct io_kiocb *req, int fd, 77 unsigned issue_flags); 78 79void __io_req_task_work_add(struct io_kiocb *req, unsigned flags); 80bool io_alloc_async_data(struct io_kiocb *req); 81void io_req_task_queue(struct io_kiocb *req); 82void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use); 83void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts); 84void io_req_task_queue_fail(struct io_kiocb *req, int ret); 85void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts); 86struct llist_node *io_handle_tw_list(struct llist_node *node, unsigned int *count, unsigned int max_entries); 87struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, unsigned int max_entries, unsigned int *count); 88void tctx_task_work(struct callback_head *cb); 89__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); 90int io_uring_alloc_task_context(struct task_struct *task, 91 struct io_ring_ctx *ctx); 92 93int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file, 94 int start, int end); 95 96int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts); 97int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr); 98int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin); 99void __io_submit_flush_completions(struct io_ring_ctx *ctx); 100int io_req_prep_async(struct io_kiocb *req); 101 102struct io_wq_work *io_wq_free_work(struct io_wq_work *work); 103void io_wq_submit_work(struct io_wq_work *work); 104 105void io_free_req(struct io_kiocb *req); 106void io_queue_next(struct io_kiocb *req); 107void io_task_refs_refill(struct io_uring_task *tctx); 108bool __io_alloc_req_refill(struct io_ring_ctx *ctx); 109 110bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task, 111 bool cancel_all); 112 113void *io_mem_alloc(size_t size); 114void io_mem_free(void *ptr); 115 116enum { 117 IO_EVENTFD_OP_SIGNAL_BIT, 118 IO_EVENTFD_OP_FREE_BIT, 119}; 120 121void io_eventfd_ops(struct rcu_head *rcu); 122void io_activate_pollwq(struct io_ring_ctx *ctx); 123 124#if defined(CONFIG_PROVE_LOCKING) 125static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx) 126{ 127 lockdep_assert(in_task()); 128 129 if (ctx->flags & IORING_SETUP_IOPOLL) { 130 lockdep_assert_held(&ctx->uring_lock); 131 } else if (!ctx->task_complete) { 132 lockdep_assert_held(&ctx->completion_lock); 133 } else if (ctx->submitter_task) { 134 /* 135 * ->submitter_task may be NULL and we can still post a CQE, 136 * if the ring has been setup with IORING_SETUP_R_DISABLED. 137 * Not from an SQE, as those cannot be submitted, but via 138 * updating tagged resources. 139 */ 140 if (ctx->submitter_task->flags & PF_EXITING) 141 lockdep_assert(current_work()); 142 else 143 lockdep_assert(current == ctx->submitter_task); 144 } 145} 146#else 147static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx) 148{ 149} 150#endif 151 152static inline void io_req_task_work_add(struct io_kiocb *req) 153{ 154 __io_req_task_work_add(req, 0); 155} 156 157#define io_for_each_link(pos, head) \ 158 for (pos = (head); pos; pos = pos->link) 159 160static inline bool io_get_cqe_overflow(struct io_ring_ctx *ctx, 161 struct io_uring_cqe **ret, 162 bool overflow) 163{ 164 io_lockdep_assert_cq_locked(ctx); 165 166 if (unlikely(ctx->cqe_cached >= ctx->cqe_sentinel)) { 167 if (unlikely(!io_cqe_cache_refill(ctx, overflow))) 168 return false; 169 } 170 *ret = ctx->cqe_cached; 171 ctx->cached_cq_tail++; 172 ctx->cqe_cached++; 173 if (ctx->flags & IORING_SETUP_CQE32) 174 ctx->cqe_cached++; 175 return true; 176} 177 178static inline bool io_get_cqe(struct io_ring_ctx *ctx, struct io_uring_cqe **ret) 179{ 180 return io_get_cqe_overflow(ctx, ret, false); 181} 182 183static __always_inline bool io_fill_cqe_req(struct io_ring_ctx *ctx, 184 struct io_kiocb *req) 185{ 186 struct io_uring_cqe *cqe; 187 188 /* 189 * If we can't get a cq entry, userspace overflowed the 190 * submission (by quite a lot). Increment the overflow count in 191 * the ring. 192 */ 193 if (unlikely(!io_get_cqe(ctx, &cqe))) 194 return false; 195 196 if (trace_io_uring_complete_enabled()) 197 trace_io_uring_complete(req->ctx, req, req->cqe.user_data, 198 req->cqe.res, req->cqe.flags, 199 req->big_cqe.extra1, req->big_cqe.extra2); 200 201 memcpy(cqe, &req->cqe, sizeof(*cqe)); 202 if (ctx->flags & IORING_SETUP_CQE32) { 203 memcpy(cqe->big_cqe, &req->big_cqe, sizeof(*cqe)); 204 memset(&req->big_cqe, 0, sizeof(req->big_cqe)); 205 } 206 return true; 207} 208 209static inline void req_set_fail(struct io_kiocb *req) 210{ 211 req->flags |= REQ_F_FAIL; 212 if (req->flags & REQ_F_CQE_SKIP) { 213 req->flags &= ~REQ_F_CQE_SKIP; 214 req->flags |= REQ_F_SKIP_LINK_CQES; 215 } 216} 217 218static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags) 219{ 220 req->cqe.res = res; 221 req->cqe.flags = cflags; 222} 223 224static inline bool req_has_async_data(struct io_kiocb *req) 225{ 226 return req->flags & REQ_F_ASYNC_DATA; 227} 228 229static inline void io_put_file(struct io_kiocb *req) 230{ 231 if (!(req->flags & REQ_F_FIXED_FILE) && req->file) 232 fput(req->file); 233} 234 235static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx, 236 unsigned issue_flags) 237{ 238 lockdep_assert_held(&ctx->uring_lock); 239 if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) 240 mutex_unlock(&ctx->uring_lock); 241} 242 243static inline void io_ring_submit_lock(struct io_ring_ctx *ctx, 244 unsigned issue_flags) 245{ 246 /* 247 * "Normal" inline submissions always hold the uring_lock, since we 248 * grab it from the system call. Same is true for the SQPOLL offload. 249 * The only exception is when we've detached the request and issue it 250 * from an async worker thread, grab the lock for that case. 251 */ 252 if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) 253 mutex_lock(&ctx->uring_lock); 254 lockdep_assert_held(&ctx->uring_lock); 255} 256 257static inline void io_commit_cqring(struct io_ring_ctx *ctx) 258{ 259 /* order cqe stores with ring update */ 260 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); 261} 262 263static inline void io_poll_wq_wake(struct io_ring_ctx *ctx) 264{ 265 if (wq_has_sleeper(&ctx->poll_wq)) 266 __wake_up(&ctx->poll_wq, TASK_NORMAL, 0, 267 poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 268} 269 270static inline void io_cqring_wake(struct io_ring_ctx *ctx) 271{ 272 /* 273 * Trigger waitqueue handler on all waiters on our waitqueue. This 274 * won't necessarily wake up all the tasks, io_should_wake() will make 275 * that decision. 276 * 277 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter 278 * set in the mask so that if we recurse back into our own poll 279 * waitqueue handlers, we know we have a dependency between eventfd or 280 * epoll and should terminate multishot poll at that point. 281 */ 282 if (wq_has_sleeper(&ctx->cq_wait)) 283 __wake_up(&ctx->cq_wait, TASK_NORMAL, 0, 284 poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 285} 286 287static inline bool io_sqring_full(struct io_ring_ctx *ctx) 288{ 289 struct io_rings *r = ctx->rings; 290 291 return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries; 292} 293 294static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) 295{ 296 struct io_rings *rings = ctx->rings; 297 unsigned int entries; 298 299 /* make sure SQ entry isn't read before tail */ 300 entries = smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; 301 return min(entries, ctx->sq_entries); 302} 303 304static inline int io_run_task_work(void) 305{ 306 bool ret = false; 307 308 /* 309 * Always check-and-clear the task_work notification signal. With how 310 * signaling works for task_work, we can find it set with nothing to 311 * run. We need to clear it for that case, like get_signal() does. 312 */ 313 if (test_thread_flag(TIF_NOTIFY_SIGNAL)) 314 clear_notify_signal(); 315 /* 316 * PF_IO_WORKER never returns to userspace, so check here if we have 317 * notify work that needs processing. 318 */ 319 if (current->flags & PF_IO_WORKER) { 320 if (test_thread_flag(TIF_NOTIFY_RESUME)) { 321 __set_current_state(TASK_RUNNING); 322 resume_user_mode_work(NULL); 323 } 324 if (current->io_uring) { 325 unsigned int count = 0; 326 327 tctx_task_work_run(current->io_uring, UINT_MAX, &count); 328 if (count) 329 ret = true; 330 } 331 } 332 if (task_work_pending(current)) { 333 __set_current_state(TASK_RUNNING); 334 task_work_run(); 335 ret = true; 336 } 337 338 return ret; 339} 340 341static inline bool io_task_work_pending(struct io_ring_ctx *ctx) 342{ 343 return task_work_pending(current) || !wq_list_empty(&ctx->work_llist); 344} 345 346static inline void io_tw_lock(struct io_ring_ctx *ctx, struct io_tw_state *ts) 347{ 348 if (!ts->locked) { 349 mutex_lock(&ctx->uring_lock); 350 ts->locked = true; 351 } 352} 353 354/* 355 * Don't complete immediately but use deferred completion infrastructure. 356 * Protected by ->uring_lock and can only be used either with 357 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex. 358 */ 359static inline void io_req_complete_defer(struct io_kiocb *req) 360 __must_hold(&req->ctx->uring_lock) 361{ 362 struct io_submit_state *state = &req->ctx->submit_state; 363 364 lockdep_assert_held(&req->ctx->uring_lock); 365 366 wq_list_add_tail(&req->comp_list, &state->compl_reqs); 367} 368 369static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx) 370{ 371 if (unlikely(ctx->off_timeout_used || ctx->drain_active || 372 ctx->has_evfd || ctx->poll_activated)) 373 __io_commit_cqring_flush(ctx); 374} 375 376static inline void io_get_task_refs(int nr) 377{ 378 struct io_uring_task *tctx = current->io_uring; 379 380 tctx->cached_refs -= nr; 381 if (unlikely(tctx->cached_refs < 0)) 382 io_task_refs_refill(tctx); 383} 384 385static inline bool io_req_cache_empty(struct io_ring_ctx *ctx) 386{ 387 return !ctx->submit_state.free_list.next; 388} 389 390extern struct kmem_cache *req_cachep; 391extern struct kmem_cache *io_buf_cachep; 392 393static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx) 394{ 395 struct io_kiocb *req; 396 397 req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list); 398 wq_stack_extract(&ctx->submit_state.free_list); 399 return req; 400} 401 402static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req) 403{ 404 if (unlikely(io_req_cache_empty(ctx))) { 405 if (!__io_alloc_req_refill(ctx)) 406 return false; 407 } 408 *req = io_extract_req(ctx); 409 return true; 410} 411 412static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx) 413{ 414 return likely(ctx->submitter_task == current); 415} 416 417static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) 418{ 419 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || 420 ctx->submitter_task == current); 421} 422 423static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) 424{ 425 io_req_set_res(req, res, 0); 426 req->io_task_work.func = io_req_task_complete; 427 io_req_task_work_add(req); 428} 429 430/* 431 * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each 432 * slot. 433 */ 434static inline size_t uring_sqe_size(struct io_ring_ctx *ctx) 435{ 436 if (ctx->flags & IORING_SETUP_SQE128) 437 return 2 * sizeof(struct io_uring_sqe); 438 return sizeof(struct io_uring_sqe); 439} 440 441static inline bool io_file_can_poll(struct io_kiocb *req) 442{ 443 if (req->flags & REQ_F_CAN_POLL) 444 return true; 445 if (file_can_poll(req->file)) { 446 req->flags |= REQ_F_CAN_POLL; 447 return true; 448 } 449 return false; 450} 451 452enum { 453 IO_CHECK_CQ_OVERFLOW_BIT, 454 IO_CHECK_CQ_DROPPED_BIT, 455}; 456 457static inline bool io_has_work(struct io_ring_ctx *ctx) 458{ 459 return test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq) || 460 !llist_empty(&ctx->work_llist); 461} 462#endif 463