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 static inline void io_req_task_work_add(struct io_kiocb *req) 83 { 84 __io_req_task_work_add(req, true); 85 } 86 87 #define io_for_each_link(pos, head) \ 88 for (pos = (head); pos; pos = pos->link) 89 90 static inline void io_cq_lock(struct io_ring_ctx *ctx) 91 __acquires(ctx->completion_lock) 92 { 93 spin_lock(&ctx->completion_lock); 94 } 95 96 static inline void io_cq_unlock(struct io_ring_ctx *ctx) 97 { 98 spin_unlock(&ctx->completion_lock); 99 } 100 101 void io_cq_unlock_post(struct io_ring_ctx *ctx); 102 103 static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx, 104 bool overflow) 105 { 106 if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) { 107 struct io_uring_cqe *cqe = ctx->cqe_cached; 108 109 ctx->cached_cq_tail++; 110 ctx->cqe_cached++; 111 if (ctx->flags & IORING_SETUP_CQE32) 112 ctx->cqe_cached++; 113 return cqe; 114 } 115 116 return __io_get_cqe(ctx, overflow); 117 } 118 119 static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx) 120 { 121 return io_get_cqe_overflow(ctx, false); 122 } 123 124 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx, 125 struct io_kiocb *req) 126 { 127 struct io_uring_cqe *cqe; 128 129 /* 130 * If we can't get a cq entry, userspace overflowed the 131 * submission (by quite a lot). Increment the overflow count in 132 * the ring. 133 */ 134 cqe = io_get_cqe(ctx); 135 if (unlikely(!cqe)) 136 return false; 137 138 trace_io_uring_complete(req->ctx, req, req->cqe.user_data, 139 req->cqe.res, req->cqe.flags, 140 (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0, 141 (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0); 142 143 memcpy(cqe, &req->cqe, sizeof(*cqe)); 144 145 if (ctx->flags & IORING_SETUP_CQE32) { 146 u64 extra1 = 0, extra2 = 0; 147 148 if (req->flags & REQ_F_CQE32_INIT) { 149 extra1 = req->extra1; 150 extra2 = req->extra2; 151 } 152 153 WRITE_ONCE(cqe->big_cqe[0], extra1); 154 WRITE_ONCE(cqe->big_cqe[1], extra2); 155 } 156 return true; 157 } 158 159 static inline bool io_fill_cqe_req(struct io_ring_ctx *ctx, 160 struct io_kiocb *req) 161 { 162 if (likely(__io_fill_cqe_req(ctx, req))) 163 return true; 164 return io_req_cqe_overflow(req); 165 } 166 167 static inline void req_set_fail(struct io_kiocb *req) 168 { 169 req->flags |= REQ_F_FAIL; 170 if (req->flags & REQ_F_CQE_SKIP) { 171 req->flags &= ~REQ_F_CQE_SKIP; 172 req->flags |= REQ_F_SKIP_LINK_CQES; 173 } 174 } 175 176 static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags) 177 { 178 req->cqe.res = res; 179 req->cqe.flags = cflags; 180 } 181 182 static inline bool req_has_async_data(struct io_kiocb *req) 183 { 184 return req->flags & REQ_F_ASYNC_DATA; 185 } 186 187 static inline void io_put_file(struct file *file) 188 { 189 if (file) 190 fput(file); 191 } 192 193 static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx, 194 unsigned issue_flags) 195 { 196 lockdep_assert_held(&ctx->uring_lock); 197 if (issue_flags & IO_URING_F_UNLOCKED) 198 mutex_unlock(&ctx->uring_lock); 199 } 200 201 static inline void io_ring_submit_lock(struct io_ring_ctx *ctx, 202 unsigned issue_flags) 203 { 204 /* 205 * "Normal" inline submissions always hold the uring_lock, since we 206 * grab it from the system call. Same is true for the SQPOLL offload. 207 * The only exception is when we've detached the request and issue it 208 * from an async worker thread, grab the lock for that case. 209 */ 210 if (issue_flags & IO_URING_F_UNLOCKED) 211 mutex_lock(&ctx->uring_lock); 212 lockdep_assert_held(&ctx->uring_lock); 213 } 214 215 static inline void io_commit_cqring(struct io_ring_ctx *ctx) 216 { 217 /* order cqe stores with ring update */ 218 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail); 219 } 220 221 /* requires smb_mb() prior, see wq_has_sleeper() */ 222 static inline void __io_cqring_wake(struct io_ring_ctx *ctx) 223 { 224 /* 225 * Trigger waitqueue handler on all waiters on our waitqueue. This 226 * won't necessarily wake up all the tasks, io_should_wake() will make 227 * that decision. 228 * 229 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter 230 * set in the mask so that if we recurse back into our own poll 231 * waitqueue handlers, we know we have a dependency between eventfd or 232 * epoll and should terminate multishot poll at that point. 233 */ 234 if (waitqueue_active(&ctx->cq_wait)) 235 __wake_up(&ctx->cq_wait, TASK_NORMAL, 0, 236 poll_to_key(EPOLL_URING_WAKE | EPOLLIN)); 237 } 238 239 static inline void io_cqring_wake(struct io_ring_ctx *ctx) 240 { 241 smp_mb(); 242 __io_cqring_wake(ctx); 243 } 244 245 static inline bool io_sqring_full(struct io_ring_ctx *ctx) 246 { 247 struct io_rings *r = ctx->rings; 248 249 return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries; 250 } 251 252 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) 253 { 254 struct io_rings *rings = ctx->rings; 255 256 /* make sure SQ entry isn't read before tail */ 257 return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; 258 } 259 260 static inline int io_run_task_work(void) 261 { 262 /* 263 * Always check-and-clear the task_work notification signal. With how 264 * signaling works for task_work, we can find it set with nothing to 265 * run. We need to clear it for that case, like get_signal() does. 266 */ 267 if (test_thread_flag(TIF_NOTIFY_SIGNAL)) 268 clear_notify_signal(); 269 if (task_work_pending(current)) { 270 __set_current_state(TASK_RUNNING); 271 task_work_run(); 272 return 1; 273 } 274 275 return 0; 276 } 277 278 static inline bool io_task_work_pending(struct io_ring_ctx *ctx) 279 { 280 return test_thread_flag(TIF_NOTIFY_SIGNAL) || 281 !wq_list_empty(&ctx->work_llist); 282 } 283 284 static inline int io_run_task_work_ctx(struct io_ring_ctx *ctx) 285 { 286 int ret = 0; 287 int ret2; 288 289 if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) 290 ret = io_run_local_work(ctx); 291 292 /* want to run this after in case more is added */ 293 ret2 = io_run_task_work(); 294 295 /* Try propagate error in favour of if tasks were run, 296 * but still make sure to run them if requested 297 */ 298 if (ret >= 0) 299 ret += ret2; 300 301 return ret; 302 } 303 304 static inline int io_run_local_work_locked(struct io_ring_ctx *ctx) 305 { 306 bool locked; 307 int ret; 308 309 if (llist_empty(&ctx->work_llist)) 310 return 0; 311 312 locked = true; 313 ret = __io_run_local_work(ctx, &locked); 314 /* shouldn't happen! */ 315 if (WARN_ON_ONCE(!locked)) 316 mutex_lock(&ctx->uring_lock); 317 return ret; 318 } 319 320 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked) 321 { 322 if (!*locked) { 323 mutex_lock(&ctx->uring_lock); 324 *locked = true; 325 } 326 } 327 328 /* 329 * Don't complete immediately but use deferred completion infrastructure. 330 * Protected by ->uring_lock and can only be used either with 331 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex. 332 */ 333 static inline void io_req_complete_defer(struct io_kiocb *req) 334 __must_hold(&req->ctx->uring_lock) 335 { 336 struct io_submit_state *state = &req->ctx->submit_state; 337 338 lockdep_assert_held(&req->ctx->uring_lock); 339 340 wq_list_add_tail(&req->comp_list, &state->compl_reqs); 341 } 342 343 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx) 344 { 345 if (unlikely(ctx->off_timeout_used || ctx->drain_active || ctx->has_evfd)) 346 __io_commit_cqring_flush(ctx); 347 } 348 349 /* must to be called somewhat shortly after putting a request */ 350 static inline void io_put_task(struct task_struct *task, int nr) 351 { 352 if (likely(task == current)) 353 task->io_uring->cached_refs += nr; 354 else 355 __io_put_task(task, nr); 356 } 357 358 static inline void io_get_task_refs(int nr) 359 { 360 struct io_uring_task *tctx = current->io_uring; 361 362 tctx->cached_refs -= nr; 363 if (unlikely(tctx->cached_refs < 0)) 364 io_task_refs_refill(tctx); 365 } 366 367 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx) 368 { 369 return !ctx->submit_state.free_list.next; 370 } 371 372 static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx) 373 { 374 if (unlikely(io_req_cache_empty(ctx))) 375 return __io_alloc_req_refill(ctx); 376 return true; 377 } 378 379 static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) 380 { 381 struct io_wq_work_node *node; 382 383 node = wq_stack_extract(&ctx->submit_state.free_list); 384 return container_of(node, struct io_kiocb, comp_list); 385 } 386 387 static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) 388 { 389 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || 390 ctx->submitter_task == current); 391 } 392 393 static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res) 394 { 395 io_req_set_res(req, res, 0); 396 req->io_task_work.func = io_req_task_complete; 397 io_req_task_work_add(req); 398 } 399 400 #endif 401