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