1 #ifndef IOU_CORE_H 2 #define IOU_CORE_H 3 4 #include <linux/errno.h> 5 #include <linux/lockdep.h> 6 #include <linux/io_uring_types.h> 7 #include <uapi/linux/eventpoll.h> 8 #include "io-wq.h" 9 #include "slist.h" 10 #include "filetable.h" 11 12 #ifndef CREATE_TRACE_POINTS 13 #include <trace/events/io_uring.h> 14 #endif 15 16 enum { 17 IOU_OK = 0, 18 IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED, 19 20 /* 21 * Intended only when both IO_URING_F_MULTISHOT is passed 22 * to indicate to the poll runner that multishot should be 23 * removed and the result is set on req->cqe.res. 24 */ 25 IOU_STOP_MULTISHOT = -ECANCELED, 26 }; 27 28 struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow); 29 bool io_req_cqe_overflow(struct io_kiocb *req); 30 int io_run_task_work_sig(struct io_ring_ctx *ctx); 31 int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked); 32 int io_run_local_work(struct io_ring_ctx *ctx); 33 void io_req_defer_failed(struct io_kiocb *req, s32 res); 34 void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags); 35 bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags); 36 bool io_aux_cqe(struct io_ring_ctx *ctx, bool defer, u64 user_data, s32 res, u32 cflags, 37 bool allow_overflow); 38 void __io_commit_cqring_flush(struct io_ring_ctx *ctx); 39 40 struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages); 41 42 struct file *io_file_get_normal(struct io_kiocb *req, int fd); 43 struct file *io_file_get_fixed(struct io_kiocb *req, int fd, 44 unsigned issue_flags); 45 46 static inline bool io_req_ffs_set(struct io_kiocb *req) 47 { 48 return req->flags & REQ_F_FIXED_FILE; 49 } 50 51 void __io_req_task_work_add(struct io_kiocb *req, bool allow_local); 52 bool io_is_uring_fops(struct file *file); 53 bool io_alloc_async_data(struct io_kiocb *req); 54 void io_req_task_queue(struct io_kiocb *req); 55 void io_queue_iowq(struct io_kiocb *req, bool *dont_use); 56 void io_req_task_complete(struct io_kiocb *req, bool *locked); 57 void io_req_task_queue_fail(struct io_kiocb *req, int ret); 58 void io_req_task_submit(struct io_kiocb *req, bool *locked); 59 void tctx_task_work(struct callback_head *cb); 60 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); 61 int io_uring_alloc_task_context(struct task_struct *task, 62 struct io_ring_ctx *ctx); 63 64 int io_poll_issue(struct io_kiocb *req, bool *locked); 65 int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr); 66 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin); 67 void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node); 68 int io_req_prep_async(struct io_kiocb *req); 69 70 struct io_wq_work *io_wq_free_work(struct io_wq_work *work); 71 void io_wq_submit_work(struct io_wq_work *work); 72 73 void io_free_req(struct io_kiocb *req); 74 void io_queue_next(struct io_kiocb *req); 75 void __io_put_task(struct task_struct *task, int nr); 76 void io_task_refs_refill(struct io_uring_task *tctx); 77 bool __io_alloc_req_refill(struct io_ring_ctx *ctx); 78 79 bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task, 80 bool cancel_all); 81 82 #define io_lockdep_assert_cq_locked(ctx) \ 83 do { \ 84 if (ctx->flags & IORING_SETUP_IOPOLL) { \ 85 lockdep_assert_held(&ctx->uring_lock); \ 86 } else if (!ctx->task_complete) { \ 87 lockdep_assert_held(&ctx->completion_lock); \ 88 } else if (ctx->submitter_task->flags & PF_EXITING) { \ 89 lockdep_assert(current_work()); \ 90 } else { \ 91 lockdep_assert(current == ctx->submitter_task); \ 92 } \ 93 } while (0) 94 95 static inline void io_req_task_work_add(struct io_kiocb *req) 96 { 97 __io_req_task_work_add(req, true); 98 } 99 100 #define io_for_each_link(pos, head) \ 101 for (pos = (head); pos; pos = pos->link) 102 103 void io_cq_unlock_post(struct io_ring_ctx *ctx); 104 105 static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx, 106 bool overflow) 107 { 108 io_lockdep_assert_cq_locked(ctx); 109 110 if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) { 111 struct io_uring_cqe *cqe = ctx->cqe_cached; 112 113 ctx->cached_cq_tail++; 114 ctx->cqe_cached++; 115 if (ctx->flags & IORING_SETUP_CQE32) 116 ctx->cqe_cached++; 117 return cqe; 118 } 119 120 return __io_get_cqe(ctx, overflow); 121 } 122 123 static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx) 124 { 125 return io_get_cqe_overflow(ctx, false); 126 } 127 128 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx, 129 struct io_kiocb *req) 130 { 131 struct io_uring_cqe *cqe; 132 133 /* 134 * If we can't get a cq entry, userspace overflowed the 135 * submission (by quite a lot). Increment the overflow count in 136 * the ring. 137 */ 138 cqe = io_get_cqe(ctx); 139 if (unlikely(!cqe)) 140 return false; 141 142 trace_io_uring_complete(req->ctx, req, req->cqe.user_data, 143 req->cqe.res, req->cqe.flags, 144 (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0, 145 (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0); 146 147 memcpy(cqe, &req->cqe, sizeof(*cqe)); 148 149 if (ctx->flags & IORING_SETUP_CQE32) { 150 u64 extra1 = 0, extra2 = 0; 151 152 if (req->flags & REQ_F_CQE32_INIT) { 153 extra1 = req->extra1; 154 extra2 = req->extra2; 155 } 156 157 WRITE_ONCE(cqe->big_cqe[0], extra1); 158 WRITE_ONCE(cqe->big_cqe[1], extra2); 159 } 160 return true; 161 } 162 163 static inline bool io_fill_cqe_req(struct io_ring_ctx *ctx, 164 struct io_kiocb *req) 165 { 166 if (likely(__io_fill_cqe_req(ctx, req))) 167 return true; 168 return io_req_cqe_overflow(req); 169 } 170 171 static inline void req_set_fail(struct io_kiocb *req) 172 { 173 req->flags |= REQ_F_FAIL; 174 if (req->flags & REQ_F_CQE_SKIP) { 175 req->flags &= ~REQ_F_CQE_SKIP; 176 req->flags |= REQ_F_SKIP_LINK_CQES; 177 } 178 } 179 180 static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags) 181 { 182 req->cqe.res = res; 183 req->cqe.flags = cflags; 184 } 185 186 static inline bool req_has_async_data(struct io_kiocb *req) 187 { 188 return req->flags & REQ_F_ASYNC_DATA; 189 } 190 191 static inline void io_put_file(struct file *file) 192 { 193 if (file) 194 fput(file); 195 } 196 197 static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx, 198 unsigned issue_flags) 199 { 200 lockdep_assert_held(&ctx->uring_lock); 201 if (issue_flags & IO_URING_F_UNLOCKED) 202 mutex_unlock(&ctx->uring_lock); 203 } 204 205 static inline void io_ring_submit_lock(struct io_ring_ctx *ctx, 206 unsigned issue_flags) 207 { 208 /* 209 * "Normal" inline submissions always hold the uring_lock, since we 210 * grab it from the system call. Same is true for the SQPOLL offload. 211 * The only exception is when we've detached the request and issue it 212 * from an async worker thread, grab the lock for that case. 213 */ 214 if (issue_flags & IO_URING_F_UNLOCKED) 215 mutex_lock(&ctx->uring_lock); 216 lockdep_assert_held(&ctx->uring_lock); 217 } 218 219 static inline void io_commit_cqring(struct io_ring_ctx *ctx) 220 { 221 /* order cqe stores with ring update */ 222 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); 223 } 224 225 /* requires smb_mb() prior, see wq_has_sleeper() */ 226 static inline void __io_cqring_wake(struct io_ring_ctx *ctx) 227 { 228 /* 229 * Trigger waitqueue handler on all waiters on our waitqueue. This 230 * won't necessarily wake up all the tasks, io_should_wake() will make 231 * that decision. 232 * 233 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter 234 * set in the mask so that if we recurse back into our own poll 235 * waitqueue handlers, we know we have a dependency between eventfd or 236 * epoll and should terminate multishot poll at that point. 237 */ 238 if (waitqueue_active(&ctx->cq_wait)) 239 __wake_up(&ctx->cq_wait, TASK_NORMAL, 0, 240 poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 241 } 242 243 static inline void io_cqring_wake(struct io_ring_ctx *ctx) 244 { 245 smp_mb(); 246 __io_cqring_wake(ctx); 247 } 248 249 static inline bool io_sqring_full(struct io_ring_ctx *ctx) 250 { 251 struct io_rings *r = ctx->rings; 252 253 return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries; 254 } 255 256 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) 257 { 258 struct io_rings *rings = ctx->rings; 259 260 /* make sure SQ entry isn't read before tail */ 261 return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; 262 } 263 264 static inline int io_run_task_work(void) 265 { 266 /* 267 * Always check-and-clear the task_work notification signal. With how 268 * signaling works for task_work, we can find it set with nothing to 269 * run. We need to clear it for that case, like get_signal() does. 270 */ 271 if (test_thread_flag(TIF_NOTIFY_SIGNAL)) 272 clear_notify_signal(); 273 if (task_work_pending(current)) { 274 __set_current_state(TASK_RUNNING); 275 task_work_run(); 276 return 1; 277 } 278 279 return 0; 280 } 281 282 static inline bool io_task_work_pending(struct io_ring_ctx *ctx) 283 { 284 return task_work_pending(current) || !wq_list_empty(&ctx->work_llist); 285 } 286 287 static inline int io_run_task_work_ctx(struct io_ring_ctx *ctx) 288 { 289 int ret = 0; 290 int ret2; 291 292 if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) 293 ret = io_run_local_work(ctx); 294 295 /* want to run this after in case more is added */ 296 ret2 = io_run_task_work(); 297 298 /* Try propagate error in favour of if tasks were run, 299 * but still make sure to run them if requested 300 */ 301 if (ret >= 0) 302 ret += ret2; 303 304 return ret; 305 } 306 307 static inline int io_run_local_work_locked(struct io_ring_ctx *ctx) 308 { 309 bool locked; 310 int ret; 311 312 if (llist_empty(&ctx->work_llist)) 313 return 0; 314 315 locked = true; 316 ret = __io_run_local_work(ctx, &locked); 317 /* shouldn't happen! */ 318 if (WARN_ON_ONCE(!locked)) 319 mutex_lock(&ctx->uring_lock); 320 return ret; 321 } 322 323 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked) 324 { 325 if (!*locked) { 326 mutex_lock(&ctx->uring_lock); 327 *locked = true; 328 } 329 } 330 331 /* 332 * Don't complete immediately but use deferred completion infrastructure. 333 * Protected by ->uring_lock and can only be used either with 334 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex. 335 */ 336 static inline void io_req_complete_defer(struct io_kiocb *req) 337 __must_hold(&req->ctx->uring_lock) 338 { 339 struct io_submit_state *state = &req->ctx->submit_state; 340 341 lockdep_assert_held(&req->ctx->uring_lock); 342 343 wq_list_add_tail(&req->comp_list, &state->compl_reqs); 344 } 345 346 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx) 347 { 348 if (unlikely(ctx->off_timeout_used || ctx->drain_active || ctx->has_evfd)) 349 __io_commit_cqring_flush(ctx); 350 } 351 352 /* must to be called somewhat shortly after putting a request */ 353 static inline void io_put_task(struct task_struct *task, int nr) 354 { 355 if (likely(task == current)) 356 task->io_uring->cached_refs += nr; 357 else 358 __io_put_task(task, nr); 359 } 360 361 static inline void io_get_task_refs(int nr) 362 { 363 struct io_uring_task *tctx = current->io_uring; 364 365 tctx->cached_refs -= nr; 366 if (unlikely(tctx->cached_refs < 0)) 367 io_task_refs_refill(tctx); 368 } 369 370 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx) 371 { 372 return !ctx->submit_state.free_list.next; 373 } 374 375 static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx) 376 { 377 if (unlikely(io_req_cache_empty(ctx))) 378 return __io_alloc_req_refill(ctx); 379 return true; 380 } 381 382 static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) 383 { 384 struct io_wq_work_node *node; 385 386 node = wq_stack_extract(&ctx->submit_state.free_list); 387 return container_of(node, struct io_kiocb, comp_list); 388 } 389 390 static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) 391 { 392 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || 393 ctx->submitter_task == current); 394 } 395 396 static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) 397 { 398 io_req_set_res(req, res, 0); 399 req->io_task_work.func = io_req_task_complete; 400 io_req_task_work_add(req); 401 } 402 403 #endif 404