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 : /* don't use deferred task_work */
20 : IOU_F_TWQ_FORCE_NORMAL = 1,
21 :
22 : /*
23 : * A hint to not wake right away but delay until there are enough of
24 : * tw's queued to match the number of CQEs the task is waiting for.
25 : *
26 : * Must not be used wirh requests generating more than one CQE.
27 : * It's also ignored unless IORING_SETUP_DEFER_TASKRUN is set.
28 : */
29 : IOU_F_TWQ_LAZY_WAKE = 2,
30 : };
31 :
32 : enum {
33 : IOU_OK = 0,
34 : IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED,
35 :
36 : /*
37 : * Intended only when both IO_URING_F_MULTISHOT is passed
38 : * to indicate to the poll runner that multishot should be
39 : * removed and the result is set on req->cqe.res.
40 : */
41 : IOU_STOP_MULTISHOT = -ECANCELED,
42 : };
43 :
44 : struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow);
45 : bool io_req_cqe_overflow(struct io_kiocb *req);
46 : int io_run_task_work_sig(struct io_ring_ctx *ctx);
47 : void io_req_defer_failed(struct io_kiocb *req, s32 res);
48 : void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags);
49 : bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags);
50 : bool io_aux_cqe(struct io_ring_ctx *ctx, bool defer, u64 user_data, s32 res, u32 cflags,
51 : bool allow_overflow);
52 : void __io_commit_cqring_flush(struct io_ring_ctx *ctx);
53 :
54 : struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages);
55 :
56 : struct file *io_file_get_normal(struct io_kiocb *req, int fd);
57 : struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
58 : unsigned issue_flags);
59 :
60 : static inline bool io_req_ffs_set(struct io_kiocb *req)
61 : {
62 0 : return req->flags & REQ_F_FIXED_FILE;
63 : }
64 :
65 : void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
66 : bool io_is_uring_fops(struct file *file);
67 : bool io_alloc_async_data(struct io_kiocb *req);
68 : void io_req_task_queue(struct io_kiocb *req);
69 : void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
70 : void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts);
71 : void io_req_task_queue_fail(struct io_kiocb *req, int ret);
72 : void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts);
73 : void tctx_task_work(struct callback_head *cb);
74 : __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
75 : int io_uring_alloc_task_context(struct task_struct *task,
76 : struct io_ring_ctx *ctx);
77 :
78 : int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts);
79 : int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
80 : int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
81 : void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
82 : int io_req_prep_async(struct io_kiocb *req);
83 :
84 : struct io_wq_work *io_wq_free_work(struct io_wq_work *work);
85 : void io_wq_submit_work(struct io_wq_work *work);
86 :
87 : void io_free_req(struct io_kiocb *req);
88 : void io_queue_next(struct io_kiocb *req);
89 : void io_task_refs_refill(struct io_uring_task *tctx);
90 : bool __io_alloc_req_refill(struct io_ring_ctx *ctx);
91 :
92 : bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
93 : bool cancel_all);
94 :
95 : #define io_lockdep_assert_cq_locked(ctx) \
96 : do { \
97 : lockdep_assert(in_task()); \
98 : \
99 : if (ctx->flags & IORING_SETUP_IOPOLL) { \
100 : lockdep_assert_held(&ctx->uring_lock); \
101 : } else if (!ctx->task_complete) { \
102 : lockdep_assert_held(&ctx->completion_lock); \
103 : } else if (ctx->submitter_task->flags & PF_EXITING) { \
104 : lockdep_assert(current_work()); \
105 : } else { \
106 : lockdep_assert(current == ctx->submitter_task); \
107 : } \
108 : } while (0)
109 :
110 : static inline void io_req_task_work_add(struct io_kiocb *req)
111 : {
112 0 : __io_req_task_work_add(req, 0);
113 : }
114 :
115 : #define io_for_each_link(pos, head) \
116 : for (pos = (head); pos; pos = pos->link)
117 :
118 : void io_cq_unlock_post(struct io_ring_ctx *ctx);
119 :
120 0 : static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx,
121 : bool overflow)
122 : {
123 0 : io_lockdep_assert_cq_locked(ctx);
124 :
125 0 : if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
126 0 : struct io_uring_cqe *cqe = ctx->cqe_cached;
127 :
128 0 : ctx->cached_cq_tail++;
129 0 : ctx->cqe_cached++;
130 0 : if (ctx->flags & IORING_SETUP_CQE32)
131 0 : ctx->cqe_cached++;
132 : return cqe;
133 : }
134 :
135 0 : return __io_get_cqe(ctx, overflow);
136 : }
137 :
138 : static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
139 : {
140 0 : return io_get_cqe_overflow(ctx, false);
141 : }
142 :
143 0 : static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
144 : struct io_kiocb *req)
145 : {
146 : struct io_uring_cqe *cqe;
147 :
148 : /*
149 : * If we can't get a cq entry, userspace overflowed the
150 : * submission (by quite a lot). Increment the overflow count in
151 : * the ring.
152 : */
153 0 : cqe = io_get_cqe(ctx);
154 0 : if (unlikely(!cqe))
155 : return false;
156 :
157 0 : trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
158 : req->cqe.res, req->cqe.flags,
159 : (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0,
160 : (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0);
161 :
162 0 : memcpy(cqe, &req->cqe, sizeof(*cqe));
163 :
164 0 : if (ctx->flags & IORING_SETUP_CQE32) {
165 0 : u64 extra1 = 0, extra2 = 0;
166 :
167 0 : if (req->flags & REQ_F_CQE32_INIT) {
168 0 : extra1 = req->extra1;
169 0 : extra2 = req->extra2;
170 : }
171 :
172 0 : WRITE_ONCE(cqe->big_cqe[0], extra1);
173 0 : WRITE_ONCE(cqe->big_cqe[1], extra2);
174 : }
175 : return true;
176 : }
177 :
178 0 : static inline bool io_fill_cqe_req(struct io_ring_ctx *ctx,
179 : struct io_kiocb *req)
180 : {
181 0 : if (likely(__io_fill_cqe_req(ctx, req)))
182 : return true;
183 0 : return io_req_cqe_overflow(req);
184 : }
185 :
186 : static inline void req_set_fail(struct io_kiocb *req)
187 : {
188 0 : req->flags |= REQ_F_FAIL;
189 0 : if (req->flags & REQ_F_CQE_SKIP) {
190 : req->flags &= ~REQ_F_CQE_SKIP;
191 0 : req->flags |= REQ_F_SKIP_LINK_CQES;
192 : }
193 : }
194 :
195 : static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
196 : {
197 0 : req->cqe.res = res;
198 0 : req->cqe.flags = cflags;
199 : }
200 :
201 : static inline bool req_has_async_data(struct io_kiocb *req)
202 : {
203 0 : return req->flags & REQ_F_ASYNC_DATA;
204 : }
205 :
206 : static inline void io_put_file(struct file *file)
207 : {
208 0 : if (file)
209 0 : fput(file);
210 : }
211 :
212 : static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx,
213 : unsigned issue_flags)
214 : {
215 : lockdep_assert_held(&ctx->uring_lock);
216 0 : if (issue_flags & IO_URING_F_UNLOCKED)
217 0 : mutex_unlock(&ctx->uring_lock);
218 : }
219 :
220 : static inline void io_ring_submit_lock(struct io_ring_ctx *ctx,
221 : unsigned issue_flags)
222 : {
223 : /*
224 : * "Normal" inline submissions always hold the uring_lock, since we
225 : * grab it from the system call. Same is true for the SQPOLL offload.
226 : * The only exception is when we've detached the request and issue it
227 : * from an async worker thread, grab the lock for that case.
228 : */
229 0 : if (issue_flags & IO_URING_F_UNLOCKED)
230 0 : mutex_lock(&ctx->uring_lock);
231 : lockdep_assert_held(&ctx->uring_lock);
232 : }
233 :
234 : static inline void io_commit_cqring(struct io_ring_ctx *ctx)
235 : {
236 : /* order cqe stores with ring update */
237 0 : smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
238 : }
239 :
240 : static inline void io_poll_wq_wake(struct io_ring_ctx *ctx)
241 : {
242 0 : if (wq_has_sleeper(&ctx->poll_wq))
243 0 : __wake_up(&ctx->poll_wq, TASK_NORMAL, 0,
244 : poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
245 : }
246 :
247 : static inline void io_cqring_wake(struct io_ring_ctx *ctx)
248 : {
249 : /*
250 : * Trigger waitqueue handler on all waiters on our waitqueue. This
251 : * won't necessarily wake up all the tasks, io_should_wake() will make
252 : * that decision.
253 : *
254 : * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter
255 : * set in the mask so that if we recurse back into our own poll
256 : * waitqueue handlers, we know we have a dependency between eventfd or
257 : * epoll and should terminate multishot poll at that point.
258 : */
259 0 : if (wq_has_sleeper(&ctx->cq_wait))
260 0 : __wake_up(&ctx->cq_wait, TASK_NORMAL, 0,
261 : poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
262 : }
263 :
264 : static inline bool io_sqring_full(struct io_ring_ctx *ctx)
265 : {
266 0 : struct io_rings *r = ctx->rings;
267 :
268 0 : return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
269 : }
270 :
271 : static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
272 : {
273 0 : struct io_rings *rings = ctx->rings;
274 : unsigned int entries;
275 :
276 : /* make sure SQ entry isn't read before tail */
277 0 : entries = smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
278 0 : return min(entries, ctx->sq_entries);
279 : }
280 :
281 0 : static inline int io_run_task_work(void)
282 : {
283 : /*
284 : * Always check-and-clear the task_work notification signal. With how
285 : * signaling works for task_work, we can find it set with nothing to
286 : * run. We need to clear it for that case, like get_signal() does.
287 : */
288 0 : if (test_thread_flag(TIF_NOTIFY_SIGNAL))
289 : clear_notify_signal();
290 : /*
291 : * PF_IO_WORKER never returns to userspace, so check here if we have
292 : * notify work that needs processing.
293 : */
294 0 : if (current->flags & PF_IO_WORKER &&
295 0 : test_thread_flag(TIF_NOTIFY_RESUME)) {
296 0 : __set_current_state(TASK_RUNNING);
297 0 : resume_user_mode_work(NULL);
298 : }
299 0 : if (task_work_pending(current)) {
300 0 : __set_current_state(TASK_RUNNING);
301 0 : task_work_run();
302 0 : return 1;
303 : }
304 :
305 : return 0;
306 : }
307 :
308 : static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
309 : {
310 0 : return task_work_pending(current) || !wq_list_empty(&ctx->work_llist);
311 : }
312 :
313 : static inline void io_tw_lock(struct io_ring_ctx *ctx, struct io_tw_state *ts)
314 : {
315 0 : if (!ts->locked) {
316 0 : mutex_lock(&ctx->uring_lock);
317 0 : ts->locked = true;
318 : }
319 : }
320 :
321 : /*
322 : * Don't complete immediately but use deferred completion infrastructure.
323 : * Protected by ->uring_lock and can only be used either with
324 : * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
325 : */
326 : static inline void io_req_complete_defer(struct io_kiocb *req)
327 : __must_hold(&req->ctx->uring_lock)
328 : {
329 0 : struct io_submit_state *state = &req->ctx->submit_state;
330 :
331 : lockdep_assert_held(&req->ctx->uring_lock);
332 :
333 0 : wq_list_add_tail(&req->comp_list, &state->compl_reqs);
334 : }
335 :
336 : static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
337 : {
338 0 : if (unlikely(ctx->off_timeout_used || ctx->drain_active ||
339 : ctx->has_evfd || ctx->poll_activated))
340 0 : __io_commit_cqring_flush(ctx);
341 : }
342 :
343 0 : static inline void io_get_task_refs(int nr)
344 : {
345 0 : struct io_uring_task *tctx = current->io_uring;
346 :
347 0 : tctx->cached_refs -= nr;
348 0 : if (unlikely(tctx->cached_refs < 0))
349 0 : io_task_refs_refill(tctx);
350 0 : }
351 :
352 : static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
353 : {
354 0 : return !ctx->submit_state.free_list.next;
355 : }
356 :
357 : extern struct kmem_cache *req_cachep;
358 :
359 : static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx)
360 : {
361 : struct io_kiocb *req;
362 :
363 0 : req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list);
364 0 : kasan_unpoison_object_data(req_cachep, req);
365 0 : wq_stack_extract(&ctx->submit_state.free_list);
366 : return req;
367 : }
368 :
369 : static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req)
370 : {
371 0 : if (unlikely(io_req_cache_empty(ctx))) {
372 0 : if (!__io_alloc_req_refill(ctx))
373 : return false;
374 : }
375 0 : *req = io_extract_req(ctx);
376 : return true;
377 : }
378 :
379 : static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx)
380 : {
381 0 : return likely(ctx->submitter_task == current);
382 : }
383 :
384 : static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
385 : {
386 0 : return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) ||
387 : ctx->submitter_task == current);
388 : }
389 :
390 : static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
391 : {
392 0 : io_req_set_res(req, res, 0);
393 0 : req->io_task_work.func = io_req_task_complete;
394 0 : io_req_task_work_add(req);
395 : }
396 :
397 : /*
398 : * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each
399 : * slot.
400 : */
401 : static inline size_t uring_sqe_size(struct io_ring_ctx *ctx)
402 : {
403 0 : if (ctx->flags & IORING_SETUP_SQE128)
404 : return 2 * sizeof(struct io_uring_sqe);
405 : return sizeof(struct io_uring_sqe);
406 : }
407 : #endif
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