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