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/io_uring_types.h> 9 #include <uapi/linux/eventpoll.h> 10 #include "io-wq.h" 11 #include "slist.h" 12 #include "filetable.h" 13 14 #ifndef CREATE_TRACE_POINTS 15 #include <trace/events/io_uring.h> 16 #endif 17 18 enum { 19 /* don't use deferred task_work */ 20 IOU_F_TWQ_FORCE_NORMAL = 1, 21 22 /* 23 * A hint to not wake right away but delay until there are enough of 24 * tw's queued to match the number of CQEs the task is waiting for. 25 * 26 * Must not be used wirh requests generating more than one CQE. 27 * It's also ignored unless IORING_SETUP_DEFER_TASKRUN is set. 28 */ 29 IOU_F_TWQ_LAZY_WAKE = 2, 30 }; 31 32 enum { 33 IOU_OK = 0, 34 IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED, 35 36 /* 37 * Intended only when both IO_URING_F_MULTISHOT is passed 38 * to indicate to the poll runner that multishot should be 39 * removed and the result is set on req->cqe.res. 40 */ 41 IOU_STOP_MULTISHOT = -ECANCELED, 42 }; 43 44 struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow); 45 bool io_req_cqe_overflow(struct io_kiocb *req); 46 int io_run_task_work_sig(struct io_ring_ctx *ctx); 47 void io_req_defer_failed(struct io_kiocb *req, s32 res); 48 void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags); 49 bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); 50 bool io_aux_cqe(const struct io_kiocb *req, bool defer, s32 res, u32 cflags, 51 bool allow_overflow); 52 void __io_commit_cqring_flush(struct io_ring_ctx *ctx); 53 54 struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages); 55 56 struct file *io_file_get_normal(struct io_kiocb *req, int fd); 57 struct file *io_file_get_fixed(struct io_kiocb *req, int fd, 58 unsigned issue_flags); 59 60 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags); 61 bool io_is_uring_fops(struct file *file); 62 bool io_alloc_async_data(struct io_kiocb *req); 63 void io_req_task_queue(struct io_kiocb *req); 64 void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use); 65 void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts); 66 void io_req_task_queue_fail(struct io_kiocb *req, int ret); 67 void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts); 68 void tctx_task_work(struct callback_head *cb); 69 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); 70 int io_uring_alloc_task_context(struct task_struct *task, 71 struct io_ring_ctx *ctx); 72 73 int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file, 74 int start, int end); 75 76 int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts); 77 int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr); 78 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin); 79 void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node); 80 int io_req_prep_async(struct io_kiocb *req); 81 82 struct io_wq_work *io_wq_free_work(struct io_wq_work *work); 83 void io_wq_submit_work(struct io_wq_work *work); 84 85 void io_free_req(struct io_kiocb *req); 86 void io_queue_next(struct io_kiocb *req); 87 void io_task_refs_refill(struct io_uring_task *tctx); 88 bool __io_alloc_req_refill(struct io_ring_ctx *ctx); 89 90 bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task, 91 bool cancel_all); 92 93 #define io_lockdep_assert_cq_locked(ctx) \ 94 do { \ 95 lockdep_assert(in_task()); \ 96 \ 97 if (ctx->flags & IORING_SETUP_IOPOLL) { \ 98 lockdep_assert_held(&ctx->uring_lock); \ 99 } else if (!ctx->task_complete) { \ 100 lockdep_assert_held(&ctx->completion_lock); \ 101 } else if (ctx->submitter_task->flags & PF_EXITING) { \ 102 lockdep_assert(current_work()); \ 103 } else { \ 104 lockdep_assert(current == ctx->submitter_task); \ 105 } \ 106 } while (0) 107 108 static inline void io_req_task_work_add(struct io_kiocb *req) 109 { 110 __io_req_task_work_add(req, 0); 111 } 112 113 #define io_for_each_link(pos, head) \ 114 for (pos = (head); pos; pos = pos->link) 115 116 void io_cq_unlock_post(struct io_ring_ctx *ctx); 117 118 static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx, 119 bool overflow) 120 { 121 io_lockdep_assert_cq_locked(ctx); 122 123 if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) { 124 struct io_uring_cqe *cqe = ctx->cqe_cached; 125 126 ctx->cached_cq_tail++; 127 ctx->cqe_cached++; 128 if (ctx->flags & IORING_SETUP_CQE32) 129 ctx->cqe_cached++; 130 return cqe; 131 } 132 133 return __io_get_cqe(ctx, overflow); 134 } 135 136 static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx) 137 { 138 return io_get_cqe_overflow(ctx, false); 139 } 140 141 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx, 142 struct io_kiocb *req) 143 { 144 struct io_uring_cqe *cqe; 145 146 /* 147 * If we can't get a cq entry, userspace overflowed the 148 * submission (by quite a lot). Increment the overflow count in 149 * the ring. 150 */ 151 cqe = io_get_cqe(ctx); 152 if (unlikely(!cqe)) 153 return false; 154 155 trace_io_uring_complete(req->ctx, req, req->cqe.user_data, 156 req->cqe.res, req->cqe.flags, 157 (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0, 158 (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0); 159 160 memcpy(cqe, &req->cqe, sizeof(*cqe)); 161 162 if (ctx->flags & IORING_SETUP_CQE32) { 163 u64 extra1 = 0, extra2 = 0; 164 165 if (req->flags & REQ_F_CQE32_INIT) { 166 extra1 = req->extra1; 167 extra2 = req->extra2; 168 } 169 170 WRITE_ONCE(cqe->big_cqe[0], extra1); 171 WRITE_ONCE(cqe->big_cqe[1], extra2); 172 } 173 return true; 174 } 175 176 static inline bool io_fill_cqe_req(struct io_ring_ctx *ctx, 177 struct io_kiocb *req) 178 { 179 if (likely(__io_fill_cqe_req(ctx, req))) 180 return true; 181 return io_req_cqe_overflow(req); 182 } 183 184 static inline void req_set_fail(struct io_kiocb *req) 185 { 186 req->flags |= REQ_F_FAIL; 187 if (req->flags & REQ_F_CQE_SKIP) { 188 req->flags &= ~REQ_F_CQE_SKIP; 189 req->flags |= REQ_F_SKIP_LINK_CQES; 190 } 191 } 192 193 static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags) 194 { 195 req->cqe.res = res; 196 req->cqe.flags = cflags; 197 } 198 199 static inline bool req_has_async_data(struct io_kiocb *req) 200 { 201 return req->flags & REQ_F_ASYNC_DATA; 202 } 203 204 static inline void io_put_file(struct file *file) 205 { 206 if (file) 207 fput(file); 208 } 209 210 static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx, 211 unsigned issue_flags) 212 { 213 lockdep_assert_held(&ctx->uring_lock); 214 if (issue_flags & IO_URING_F_UNLOCKED) 215 mutex_unlock(&ctx->uring_lock); 216 } 217 218 static inline void io_ring_submit_lock(struct io_ring_ctx *ctx, 219 unsigned issue_flags) 220 { 221 /* 222 * "Normal" inline submissions always hold the uring_lock, since we 223 * grab it from the system call. Same is true for the SQPOLL offload. 224 * The only exception is when we've detached the request and issue it 225 * from an async worker thread, grab the lock for that case. 226 */ 227 if (issue_flags & IO_URING_F_UNLOCKED) 228 mutex_lock(&ctx->uring_lock); 229 lockdep_assert_held(&ctx->uring_lock); 230 } 231 232 static inline void io_commit_cqring(struct io_ring_ctx *ctx) 233 { 234 /* order cqe stores with ring update */ 235 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); 236 } 237 238 static inline void io_poll_wq_wake(struct io_ring_ctx *ctx) 239 { 240 if (wq_has_sleeper(&ctx->poll_wq)) 241 __wake_up(&ctx->poll_wq, TASK_NORMAL, 0, 242 poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 243 } 244 245 static inline void io_cqring_wake(struct io_ring_ctx *ctx) 246 { 247 /* 248 * Trigger waitqueue handler on all waiters on our waitqueue. This 249 * won't necessarily wake up all the tasks, io_should_wake() will make 250 * that decision. 251 * 252 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter 253 * set in the mask so that if we recurse back into our own poll 254 * waitqueue handlers, we know we have a dependency between eventfd or 255 * epoll and should terminate multishot poll at that point. 256 */ 257 if (wq_has_sleeper(&ctx->cq_wait)) 258 __wake_up(&ctx->cq_wait, TASK_NORMAL, 0, 259 poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 260 } 261 262 static inline bool io_sqring_full(struct io_ring_ctx *ctx) 263 { 264 struct io_rings *r = ctx->rings; 265 266 return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries; 267 } 268 269 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) 270 { 271 struct io_rings *rings = ctx->rings; 272 unsigned int entries; 273 274 /* make sure SQ entry isn't read before tail */ 275 entries = smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; 276 return min(entries, ctx->sq_entries); 277 } 278 279 static inline int io_run_task_work(void) 280 { 281 /* 282 * Always check-and-clear the task_work notification signal. With how 283 * signaling works for task_work, we can find it set with nothing to 284 * run. We need to clear it for that case, like get_signal() does. 285 */ 286 if (test_thread_flag(TIF_NOTIFY_SIGNAL)) 287 clear_notify_signal(); 288 /* 289 * PF_IO_WORKER never returns to userspace, so check here if we have 290 * notify work that needs processing. 291 */ 292 if (current->flags & PF_IO_WORKER && 293 test_thread_flag(TIF_NOTIFY_RESUME)) { 294 __set_current_state(TASK_RUNNING); 295 resume_user_mode_work(NULL); 296 } 297 if (task_work_pending(current)) { 298 __set_current_state(TASK_RUNNING); 299 task_work_run(); 300 return 1; 301 } 302 303 return 0; 304 } 305 306 static inline bool io_task_work_pending(struct io_ring_ctx *ctx) 307 { 308 return task_work_pending(current) || !wq_list_empty(&ctx->work_llist); 309 } 310 311 static inline void io_tw_lock(struct io_ring_ctx *ctx, struct io_tw_state *ts) 312 { 313 if (!ts->locked) { 314 mutex_lock(&ctx->uring_lock); 315 ts->locked = true; 316 } 317 } 318 319 /* 320 * Don't complete immediately but use deferred completion infrastructure. 321 * Protected by ->uring_lock and can only be used either with 322 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex. 323 */ 324 static inline void io_req_complete_defer(struct io_kiocb *req) 325 __must_hold(&req->ctx->uring_lock) 326 { 327 struct io_submit_state *state = &req->ctx->submit_state; 328 329 lockdep_assert_held(&req->ctx->uring_lock); 330 331 wq_list_add_tail(&req->comp_list, &state->compl_reqs); 332 } 333 334 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx) 335 { 336 if (unlikely(ctx->off_timeout_used || ctx->drain_active || 337 ctx->has_evfd || ctx->poll_activated)) 338 __io_commit_cqring_flush(ctx); 339 } 340 341 static inline void io_get_task_refs(int nr) 342 { 343 struct io_uring_task *tctx = current->io_uring; 344 345 tctx->cached_refs -= nr; 346 if (unlikely(tctx->cached_refs < 0)) 347 io_task_refs_refill(tctx); 348 } 349 350 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx) 351 { 352 return !ctx->submit_state.free_list.next; 353 } 354 355 extern struct kmem_cache *req_cachep; 356 357 static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx) 358 { 359 struct io_kiocb *req; 360 361 req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list); 362 kasan_unpoison_object_data(req_cachep, req); 363 wq_stack_extract(&ctx->submit_state.free_list); 364 return req; 365 } 366 367 static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req) 368 { 369 if (unlikely(io_req_cache_empty(ctx))) { 370 if (!__io_alloc_req_refill(ctx)) 371 return false; 372 } 373 *req = io_extract_req(ctx); 374 return true; 375 } 376 377 static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx) 378 { 379 return likely(ctx->submitter_task == current); 380 } 381 382 static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) 383 { 384 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || 385 ctx->submitter_task == current); 386 } 387 388 static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) 389 { 390 io_req_set_res(req, res, 0); 391 req->io_task_work.func = io_req_task_complete; 392 io_req_task_work_add(req); 393 } 394 395 /* 396 * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each 397 * slot. 398 */ 399 static inline size_t uring_sqe_size(struct io_ring_ctx *ctx) 400 { 401 if (ctx->flags & IORING_SETUP_SQE128) 402 return 2 * sizeof(struct io_uring_sqe); 403 return sizeof(struct io_uring_sqe); 404 } 405 #endif 406