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