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_complete_failed(struct io_kiocb *req, s32 res);
34 void __io_req_complete(struct io_kiocb *req, unsigned issue_flags);
35 void io_req_complete_post(struct io_kiocb *req);
36 bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags,
37 		     bool allow_overflow);
38 bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags,
39 		     bool allow_overflow);
40 void __io_commit_cqring_flush(struct io_ring_ctx *ctx);
41 
42 struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages);
43 
44 struct file *io_file_get_normal(struct io_kiocb *req, int fd);
45 struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
46 			       unsigned issue_flags);
47 
io_req_ffs_set(struct io_kiocb * req)48 static inline bool io_req_ffs_set(struct io_kiocb *req)
49 {
50 	return req->flags & REQ_F_FIXED_FILE;
51 }
52 
53 void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
54 bool io_is_uring_fops(struct file *file);
55 bool io_alloc_async_data(struct io_kiocb *req);
56 void io_req_task_queue(struct io_kiocb *req);
57 void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
58 void io_req_task_complete(struct io_kiocb *req, bool *locked);
59 void io_req_task_queue_fail(struct io_kiocb *req, int ret);
60 void io_req_task_submit(struct io_kiocb *req, bool *locked);
61 void tctx_task_work(struct callback_head *cb);
62 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
63 int io_uring_alloc_task_context(struct task_struct *task,
64 				struct io_ring_ctx *ctx);
65 
66 int io_poll_issue(struct io_kiocb *req, bool *locked);
67 int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
68 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
69 void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
70 int io_req_prep_async(struct io_kiocb *req);
71 
72 struct io_wq_work *io_wq_free_work(struct io_wq_work *work);
73 void io_wq_submit_work(struct io_wq_work *work);
74 
75 void io_free_req(struct io_kiocb *req);
76 void io_queue_next(struct io_kiocb *req);
77 void __io_put_task(struct task_struct *task, int nr);
78 void io_task_refs_refill(struct io_uring_task *tctx);
79 bool __io_alloc_req_refill(struct io_ring_ctx *ctx);
80 
81 bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
82 			bool cancel_all);
83 
io_req_task_work_add(struct io_kiocb * req)84 static inline void io_req_task_work_add(struct io_kiocb *req)
85 {
86 	__io_req_task_work_add(req, true);
87 }
88 
89 #define io_for_each_link(pos, head) \
90 	for (pos = (head); pos; pos = pos->link)
91 
io_cq_lock(struct io_ring_ctx * ctx)92 static inline void io_cq_lock(struct io_ring_ctx *ctx)
93 	__acquires(ctx->completion_lock)
94 {
95 	spin_lock(&ctx->completion_lock);
96 }
97 
98 void io_cq_unlock_post(struct io_ring_ctx *ctx);
99 
io_get_cqe_overflow(struct io_ring_ctx * ctx,bool overflow)100 static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx,
101 						       bool overflow)
102 {
103 	if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
104 		struct io_uring_cqe *cqe = ctx->cqe_cached;
105 
106 		ctx->cached_cq_tail++;
107 		ctx->cqe_cached++;
108 		if (ctx->flags & IORING_SETUP_CQE32)
109 			ctx->cqe_cached++;
110 		return cqe;
111 	}
112 
113 	return __io_get_cqe(ctx, overflow);
114 }
115 
io_get_cqe(struct io_ring_ctx * ctx)116 static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
117 {
118 	return io_get_cqe_overflow(ctx, false);
119 }
120 
__io_fill_cqe_req(struct io_ring_ctx * ctx,struct io_kiocb * req)121 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
122 				     struct io_kiocb *req)
123 {
124 	struct io_uring_cqe *cqe;
125 
126 	/*
127 	 * If we can't get a cq entry, userspace overflowed the
128 	 * submission (by quite a lot). Increment the overflow count in
129 	 * the ring.
130 	 */
131 	cqe = io_get_cqe(ctx);
132 	if (unlikely(!cqe))
133 		return io_req_cqe_overflow(req);
134 
135 	trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
136 				req->cqe.res, req->cqe.flags,
137 				(req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0,
138 				(req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0);
139 
140 	memcpy(cqe, &req->cqe, sizeof(*cqe));
141 
142 	if (ctx->flags & IORING_SETUP_CQE32) {
143 		u64 extra1 = 0, extra2 = 0;
144 
145 		if (req->flags & REQ_F_CQE32_INIT) {
146 			extra1 = req->extra1;
147 			extra2 = req->extra2;
148 		}
149 
150 		WRITE_ONCE(cqe->big_cqe[0], extra1);
151 		WRITE_ONCE(cqe->big_cqe[1], extra2);
152 	}
153 	return true;
154 }
155 
req_set_fail(struct io_kiocb * req)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 
io_req_set_res(struct io_kiocb * req,s32 res,u32 cflags)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 
req_has_async_data(struct io_kiocb * req)171 static inline bool req_has_async_data(struct io_kiocb *req)
172 {
173 	return req->flags & REQ_F_ASYNC_DATA;
174 }
175 
io_put_file(struct file * file)176 static inline void io_put_file(struct file *file)
177 {
178 	if (file)
179 		fput(file);
180 }
181 
io_ring_submit_unlock(struct io_ring_ctx * ctx,unsigned issue_flags)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 
io_ring_submit_lock(struct io_ring_ctx * ctx,unsigned issue_flags)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 
io_commit_cqring(struct io_ring_ctx * ctx)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() */
__io_cqring_wake(struct io_ring_ctx * ctx)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 
io_cqring_wake(struct io_ring_ctx * ctx)228 static inline void io_cqring_wake(struct io_ring_ctx *ctx)
229 {
230 	smp_mb();
231 	__io_cqring_wake(ctx);
232 }
233 
io_sqring_full(struct io_ring_ctx * ctx)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 
io_sqring_entries(struct io_ring_ctx * ctx)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 
io_run_task_work(void)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 
io_task_work_pending(struct io_ring_ctx * ctx)267 static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
268 {
269 	return test_thread_flag(TIF_NOTIFY_SIGNAL) ||
270 		!wq_list_empty(&ctx->work_llist);
271 }
272 
io_run_task_work_ctx(struct io_ring_ctx * ctx)273 static inline int io_run_task_work_ctx(struct io_ring_ctx *ctx)
274 {
275 	int ret = 0;
276 	int ret2;
277 
278 	if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
279 		ret = io_run_local_work(ctx);
280 
281 	/* want to run this after in case more is added */
282 	ret2 = io_run_task_work();
283 
284 	/* Try propagate error in favour of if tasks were run,
285 	 * but still make sure to run them if requested
286 	 */
287 	if (ret >= 0)
288 		ret += ret2;
289 
290 	return ret;
291 }
292 
io_run_local_work_locked(struct io_ring_ctx * ctx)293 static inline int io_run_local_work_locked(struct io_ring_ctx *ctx)
294 {
295 	bool locked;
296 	int ret;
297 
298 	if (llist_empty(&ctx->work_llist))
299 		return 0;
300 
301 	locked = true;
302 	ret = __io_run_local_work(ctx, &locked);
303 	/* shouldn't happen! */
304 	if (WARN_ON_ONCE(!locked))
305 		mutex_lock(&ctx->uring_lock);
306 	return ret;
307 }
308 
io_tw_lock(struct io_ring_ctx * ctx,bool * locked)309 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
310 {
311 	if (!*locked) {
312 		mutex_lock(&ctx->uring_lock);
313 		*locked = true;
314 	}
315 }
316 
317 /*
318  * Don't complete immediately but use deferred completion infrastructure.
319  * Protected by ->uring_lock and can only be used either with
320  * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
321  */
io_req_complete_defer(struct io_kiocb * req)322 static inline void io_req_complete_defer(struct io_kiocb *req)
323 	__must_hold(&req->ctx->uring_lock)
324 {
325 	struct io_submit_state *state = &req->ctx->submit_state;
326 
327 	lockdep_assert_held(&req->ctx->uring_lock);
328 
329 	wq_list_add_tail(&req->comp_list, &state->compl_reqs);
330 }
331 
io_commit_cqring_flush(struct io_ring_ctx * ctx)332 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
333 {
334 	if (unlikely(ctx->off_timeout_used || ctx->drain_active || ctx->has_evfd))
335 		__io_commit_cqring_flush(ctx);
336 }
337 
338 /* must to be called somewhat shortly after putting a request */
io_put_task(struct task_struct * task,int nr)339 static inline void io_put_task(struct task_struct *task, int nr)
340 {
341 	if (likely(task == current))
342 		task->io_uring->cached_refs += nr;
343 	else
344 		__io_put_task(task, nr);
345 }
346 
io_get_task_refs(int nr)347 static inline void io_get_task_refs(int nr)
348 {
349 	struct io_uring_task *tctx = current->io_uring;
350 
351 	tctx->cached_refs -= nr;
352 	if (unlikely(tctx->cached_refs < 0))
353 		io_task_refs_refill(tctx);
354 }
355 
io_req_cache_empty(struct io_ring_ctx * ctx)356 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
357 {
358 	return !ctx->submit_state.free_list.next;
359 }
360 
io_alloc_req_refill(struct io_ring_ctx * ctx)361 static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
362 {
363 	if (unlikely(io_req_cache_empty(ctx)))
364 		return __io_alloc_req_refill(ctx);
365 	return true;
366 }
367 
io_alloc_req(struct io_ring_ctx * ctx)368 static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
369 {
370 	struct io_wq_work_node *node;
371 
372 	node = wq_stack_extract(&ctx->submit_state.free_list);
373 	return container_of(node, struct io_kiocb, comp_list);
374 }
375 
io_allowed_run_tw(struct io_ring_ctx * ctx)376 static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
377 {
378 	return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) ||
379 		      ctx->submitter_task == current);
380 }
381 
io_req_queue_tw_complete(struct io_kiocb * req,s32 res)382 static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
383 {
384 	io_req_set_res(req, res, 0);
385 	req->io_task_work.func = io_req_task_complete;
386 	io_req_task_work_add(req);
387 }
388 
389 #endif
390