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