xref: /linux/io_uring/io_uring.h (revision 23c48a124b469cee2eb0c75e6d22d366d1caa118)
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 "io-wq.h"
8 #include "slist.h"
9 #include "filetable.h"
10 
11 #ifndef CREATE_TRACE_POINTS
12 #include <trace/events/io_uring.h>
13 #endif
14 
15 enum {
16 	IOU_OK			= 0,
17 	IOU_ISSUE_SKIP_COMPLETE	= -EIOCBQUEUED,
18 
19 	/*
20 	 * Intended only when both REQ_F_POLLED and REQ_F_APOLL_MULTISHOT
21 	 * are set to indicate to the poll runner that multishot should be
22 	 * removed and the result is set on req->cqe.res.
23 	 */
24 	IOU_STOP_MULTISHOT	= -ECANCELED,
25 };
26 
27 struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx);
28 bool io_req_cqe_overflow(struct io_kiocb *req);
29 int io_run_task_work_sig(void);
30 void io_req_complete_failed(struct io_kiocb *req, s32 res);
31 void __io_req_complete(struct io_kiocb *req, unsigned issue_flags);
32 void io_req_complete_post(struct io_kiocb *req);
33 void __io_req_complete_post(struct io_kiocb *req);
34 bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags,
35 		     bool allow_overflow);
36 bool io_fill_cqe_aux(struct io_ring_ctx *ctx, 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 	return req->flags & REQ_F_FIXED_FILE;
49 }
50 
51 bool io_is_uring_fops(struct file *file);
52 bool io_alloc_async_data(struct io_kiocb *req);
53 void io_req_task_work_add(struct io_kiocb *req);
54 void io_req_tw_post_queue(struct io_kiocb *req, s32 res, u32 cflags);
55 void io_req_task_queue(struct io_kiocb *req);
56 void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
57 void io_req_task_complete(struct io_kiocb *req, bool *locked);
58 void io_req_task_queue_fail(struct io_kiocb *req, int ret);
59 void io_req_task_submit(struct io_kiocb *req, bool *locked);
60 void tctx_task_work(struct callback_head *cb);
61 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
62 int io_uring_alloc_task_context(struct task_struct *task,
63 				struct io_ring_ctx *ctx);
64 
65 int io_poll_issue(struct io_kiocb *req, bool *locked);
66 int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
67 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
68 void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
69 int io_req_prep_async(struct io_kiocb *req);
70 
71 struct io_wq_work *io_wq_free_work(struct io_wq_work *work);
72 void io_wq_submit_work(struct io_wq_work *work);
73 
74 void io_free_req(struct io_kiocb *req);
75 void io_queue_next(struct io_kiocb *req);
76 void __io_put_task(struct task_struct *task, int nr);
77 void io_task_refs_refill(struct io_uring_task *tctx);
78 bool __io_alloc_req_refill(struct io_ring_ctx *ctx);
79 
80 bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
81 			bool cancel_all);
82 
83 #define io_for_each_link(pos, head) \
84 	for (pos = (head); pos; pos = pos->link)
85 
86 static inline void io_cq_lock(struct io_ring_ctx *ctx)
87 	__acquires(ctx->completion_lock)
88 {
89 	spin_lock(&ctx->completion_lock);
90 }
91 
92 void io_cq_unlock_post(struct io_ring_ctx *ctx);
93 
94 static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
95 {
96 	if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
97 		struct io_uring_cqe *cqe = ctx->cqe_cached;
98 
99 		ctx->cached_cq_tail++;
100 		ctx->cqe_cached++;
101 		if (ctx->flags & IORING_SETUP_CQE32)
102 			ctx->cqe_cached++;
103 		return cqe;
104 	}
105 
106 	return __io_get_cqe(ctx);
107 }
108 
109 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
110 				     struct io_kiocb *req)
111 {
112 	struct io_uring_cqe *cqe;
113 
114 	/*
115 	 * If we can't get a cq entry, userspace overflowed the
116 	 * submission (by quite a lot). Increment the overflow count in
117 	 * the ring.
118 	 */
119 	cqe = io_get_cqe(ctx);
120 	if (unlikely(!cqe))
121 		return io_req_cqe_overflow(req);
122 
123 	trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
124 				req->cqe.res, req->cqe.flags,
125 				(req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0,
126 				(req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0);
127 
128 	memcpy(cqe, &req->cqe, sizeof(*cqe));
129 
130 	if (ctx->flags & IORING_SETUP_CQE32) {
131 		u64 extra1 = 0, extra2 = 0;
132 
133 		if (req->flags & REQ_F_CQE32_INIT) {
134 			extra1 = req->extra1;
135 			extra2 = req->extra2;
136 		}
137 
138 		WRITE_ONCE(cqe->big_cqe[0], extra1);
139 		WRITE_ONCE(cqe->big_cqe[1], extra2);
140 	}
141 	return true;
142 }
143 
144 static inline void req_set_fail(struct io_kiocb *req)
145 {
146 	req->flags |= REQ_F_FAIL;
147 	if (req->flags & REQ_F_CQE_SKIP) {
148 		req->flags &= ~REQ_F_CQE_SKIP;
149 		req->flags |= REQ_F_SKIP_LINK_CQES;
150 	}
151 }
152 
153 static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
154 {
155 	req->cqe.res = res;
156 	req->cqe.flags = cflags;
157 }
158 
159 static inline bool req_has_async_data(struct io_kiocb *req)
160 {
161 	return req->flags & REQ_F_ASYNC_DATA;
162 }
163 
164 static inline void io_put_file(struct file *file)
165 {
166 	if (file)
167 		fput(file);
168 }
169 
170 static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx,
171 					 unsigned issue_flags)
172 {
173 	lockdep_assert_held(&ctx->uring_lock);
174 	if (issue_flags & IO_URING_F_UNLOCKED)
175 		mutex_unlock(&ctx->uring_lock);
176 }
177 
178 static inline void io_ring_submit_lock(struct io_ring_ctx *ctx,
179 				       unsigned issue_flags)
180 {
181 	/*
182 	 * "Normal" inline submissions always hold the uring_lock, since we
183 	 * grab it from the system call. Same is true for the SQPOLL offload.
184 	 * The only exception is when we've detached the request and issue it
185 	 * from an async worker thread, grab the lock for that case.
186 	 */
187 	if (issue_flags & IO_URING_F_UNLOCKED)
188 		mutex_lock(&ctx->uring_lock);
189 	lockdep_assert_held(&ctx->uring_lock);
190 }
191 
192 static inline void io_commit_cqring(struct io_ring_ctx *ctx)
193 {
194 	/* order cqe stores with ring update */
195 	smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
196 }
197 
198 static inline void io_cqring_wake(struct io_ring_ctx *ctx)
199 {
200 	/*
201 	 * wake_up_all() may seem excessive, but io_wake_function() and
202 	 * io_should_wake() handle the termination of the loop and only
203 	 * wake as many waiters as we need to.
204 	 */
205 	if (wq_has_sleeper(&ctx->cq_wait))
206 		wake_up_all(&ctx->cq_wait);
207 }
208 
209 static inline bool io_sqring_full(struct io_ring_ctx *ctx)
210 {
211 	struct io_rings *r = ctx->rings;
212 
213 	return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
214 }
215 
216 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
217 {
218 	struct io_rings *rings = ctx->rings;
219 
220 	/* make sure SQ entry isn't read before tail */
221 	return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
222 }
223 
224 static inline bool io_run_task_work(void)
225 {
226 	if (test_thread_flag(TIF_NOTIFY_SIGNAL)) {
227 		__set_current_state(TASK_RUNNING);
228 		clear_notify_signal();
229 		if (task_work_pending(current))
230 			task_work_run();
231 		return true;
232 	}
233 
234 	return false;
235 }
236 
237 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
238 {
239 	if (!*locked) {
240 		mutex_lock(&ctx->uring_lock);
241 		*locked = true;
242 	}
243 }
244 
245 /*
246  * Don't complete immediately but use deferred completion infrastructure.
247  * Protected by ->uring_lock and can only be used either with
248  * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
249  */
250 static inline void io_req_complete_defer(struct io_kiocb *req)
251 	__must_hold(&req->ctx->uring_lock)
252 {
253 	struct io_submit_state *state = &req->ctx->submit_state;
254 
255 	lockdep_assert_held(&req->ctx->uring_lock);
256 
257 	wq_list_add_tail(&req->comp_list, &state->compl_reqs);
258 }
259 
260 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
261 {
262 	if (unlikely(ctx->off_timeout_used || ctx->drain_active || ctx->has_evfd))
263 		__io_commit_cqring_flush(ctx);
264 }
265 
266 /* must to be called somewhat shortly after putting a request */
267 static inline void io_put_task(struct task_struct *task, int nr)
268 {
269 	if (likely(task == current))
270 		task->io_uring->cached_refs += nr;
271 	else
272 		__io_put_task(task, nr);
273 }
274 
275 static inline void io_get_task_refs(int nr)
276 {
277 	struct io_uring_task *tctx = current->io_uring;
278 
279 	tctx->cached_refs -= nr;
280 	if (unlikely(tctx->cached_refs < 0))
281 		io_task_refs_refill(tctx);
282 }
283 
284 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
285 {
286 	return !ctx->submit_state.free_list.next;
287 }
288 
289 static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
290 {
291 	if (unlikely(io_req_cache_empty(ctx)))
292 		return __io_alloc_req_refill(ctx);
293 	return true;
294 }
295 
296 static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
297 {
298 	struct io_wq_work_node *node;
299 
300 	node = wq_stack_extract(&ctx->submit_state.free_list);
301 	return container_of(node, struct io_kiocb, comp_list);
302 }
303 
304 #endif
305