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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
16enum {
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
28struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow);
29bool io_req_cqe_overflow(struct io_kiocb *req);
30int io_run_task_work_sig(struct io_ring_ctx *ctx);
31int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked);
32int io_run_local_work(struct io_ring_ctx *ctx);
33void io_req_defer_failed(struct io_kiocb *req, s32 res);
34void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags);
35bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags);
36bool io_aux_cqe(struct io_ring_ctx *ctx, bool defer, u64 user_data, s32 res, u32 cflags,
37 bool allow_overflow);
38void __io_commit_cqring_flush(struct io_ring_ctx *ctx);
39
40struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages);
41
42struct file *io_file_get_normal(struct io_kiocb *req, int fd);
43struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
44 unsigned issue_flags);
45
46static inline bool io_req_ffs_set(struct io_kiocb *req)
47{
48 return req->flags & REQ_F_FIXED_FILE;
49}
50
51void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
52bool io_is_uring_fops(struct file *file);
53bool io_alloc_async_data(struct io_kiocb *req);
54void io_req_task_queue(struct io_kiocb *req);
55void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
56void io_req_task_complete(struct io_kiocb *req, bool *locked);
57void io_req_task_queue_fail(struct io_kiocb *req, int ret);
58void io_req_task_submit(struct io_kiocb *req, bool *locked);
59void tctx_task_work(struct callback_head *cb);
60__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
61int io_uring_alloc_task_context(struct task_struct *task,
62 struct io_ring_ctx *ctx);
63
64int io_poll_issue(struct io_kiocb *req, bool *locked);
65int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
66int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
67void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
68int io_req_prep_async(struct io_kiocb *req);
69
70struct io_wq_work *io_wq_free_work(struct io_wq_work *work);
71void io_wq_submit_work(struct io_wq_work *work);
72
73void io_free_req(struct io_kiocb *req);
74void io_queue_next(struct io_kiocb *req);
75void __io_put_task(struct task_struct *task, int nr);
76void io_task_refs_refill(struct io_uring_task *tctx);
77bool __io_alloc_req_refill(struct io_ring_ctx *ctx);
78
79bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
80 bool cancel_all);
81
82#define io_lockdep_assert_cq_locked(ctx) \
83 do { \
84 if (ctx->flags & IORING_SETUP_IOPOLL) { \
85 lockdep_assert_held(&ctx->uring_lock); \
86 } else if (!ctx->task_complete) { \
87 lockdep_assert_held(&ctx->completion_lock); \
88 } else if (ctx->submitter_task->flags & PF_EXITING) { \
89 lockdep_assert(current_work()); \
90 } else { \
91 lockdep_assert(current == ctx->submitter_task); \
92 } \
93 } while (0)
94
95static inline void io_req_task_work_add(struct io_kiocb *req)
96{
97 __io_req_task_work_add(req, true);
98}
99
100#define io_for_each_link(pos, head) \
101 for (pos = (head); pos; pos = pos->link)
102
103void io_cq_unlock_post(struct io_ring_ctx *ctx);
104
105static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx,
106 bool overflow)
107{
108 io_lockdep_assert_cq_locked(ctx);
109
110 if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
111 struct io_uring_cqe *cqe = ctx->cqe_cached;
112
113 ctx->cached_cq_tail++;
114 ctx->cqe_cached++;
115 if (ctx->flags & IORING_SETUP_CQE32)
116 ctx->cqe_cached++;
117 return cqe;
118 }
119
120 return __io_get_cqe(ctx, overflow);
121}
122
123static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
124{
125 return io_get_cqe_overflow(ctx, false);
126}
127
128static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
129 struct io_kiocb *req)
130{
131 struct io_uring_cqe *cqe;
132
133 /*
134 * If we can't get a cq entry, userspace overflowed the
135 * submission (by quite a lot). Increment the overflow count in
136 * the ring.
137 */
138 cqe = io_get_cqe(ctx);
139 if (unlikely(!cqe))
140 return false;
141
142 trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
143 req->cqe.res, req->cqe.flags,
144 (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0,
145 (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0);
146
147 memcpy(cqe, &req->cqe, sizeof(*cqe));
148
149 if (ctx->flags & IORING_SETUP_CQE32) {
150 u64 extra1 = 0, extra2 = 0;
151
152 if (req->flags & REQ_F_CQE32_INIT) {
153 extra1 = req->extra1;
154 extra2 = req->extra2;
155 }
156
157 WRITE_ONCE(cqe->big_cqe[0], extra1);
158 WRITE_ONCE(cqe->big_cqe[1], extra2);
159 }
160 return true;
161}
162
163static inline bool io_fill_cqe_req(struct io_ring_ctx *ctx,
164 struct io_kiocb *req)
165{
166 if (likely(__io_fill_cqe_req(ctx, req)))
167 return true;
168 return io_req_cqe_overflow(req);
169}
170
171static inline void req_set_fail(struct io_kiocb *req)
172{
173 req->flags |= REQ_F_FAIL;
174 if (req->flags & REQ_F_CQE_SKIP) {
175 req->flags &= ~REQ_F_CQE_SKIP;
176 req->flags |= REQ_F_SKIP_LINK_CQES;
177 }
178}
179
180static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
181{
182 req->cqe.res = res;
183 req->cqe.flags = cflags;
184}
185
186static inline bool req_has_async_data(struct io_kiocb *req)
187{
188 return req->flags & REQ_F_ASYNC_DATA;
189}
190
191static inline void io_put_file(struct file *file)
192{
193 if (file)
194 fput(file);
195}
196
197static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx,
198 unsigned issue_flags)
199{
200 lockdep_assert_held(&ctx->uring_lock);
201 if (issue_flags & IO_URING_F_UNLOCKED)
202 mutex_unlock(&ctx->uring_lock);
203}
204
205static inline void io_ring_submit_lock(struct io_ring_ctx *ctx,
206 unsigned issue_flags)
207{
208 /*
209 * "Normal" inline submissions always hold the uring_lock, since we
210 * grab it from the system call. Same is true for the SQPOLL offload.
211 * The only exception is when we've detached the request and issue it
212 * from an async worker thread, grab the lock for that case.
213 */
214 if (issue_flags & IO_URING_F_UNLOCKED)
215 mutex_lock(&ctx->uring_lock);
216 lockdep_assert_held(&ctx->uring_lock);
217}
218
219static inline void io_commit_cqring(struct io_ring_ctx *ctx)
220{
221 /* order cqe stores with ring update */
222 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
223}
224
225/* requires smb_mb() prior, see wq_has_sleeper() */
226static inline void __io_cqring_wake(struct io_ring_ctx *ctx)
227{
228 /*
229 * Trigger waitqueue handler on all waiters on our waitqueue. This
230 * won't necessarily wake up all the tasks, io_should_wake() will make
231 * that decision.
232 *
233 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter
234 * set in the mask so that if we recurse back into our own poll
235 * waitqueue handlers, we know we have a dependency between eventfd or
236 * epoll and should terminate multishot poll at that point.
237 */
238 if (waitqueue_active(&ctx->cq_wait))
239 __wake_up(&ctx->cq_wait, TASK_NORMAL, 0,
240 poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
241}
242
243static inline void io_cqring_wake(struct io_ring_ctx *ctx)
244{
245 smp_mb();
246 __io_cqring_wake(ctx);
247}
248
249static inline bool io_sqring_full(struct io_ring_ctx *ctx)
250{
251 struct io_rings *r = ctx->rings;
252
253 return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
254}
255
256static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
257{
258 struct io_rings *rings = ctx->rings;
259
260 /* make sure SQ entry isn't read before tail */
261 return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
262}
263
264static inline int io_run_task_work(void)
265{
266 /*
267 * Always check-and-clear the task_work notification signal. With how
268 * signaling works for task_work, we can find it set with nothing to
269 * run. We need to clear it for that case, like get_signal() does.
270 */
271 if (test_thread_flag(TIF_NOTIFY_SIGNAL))
272 clear_notify_signal();
273 if (task_work_pending(current)) {
274 __set_current_state(TASK_RUNNING);
275 task_work_run();
276 return 1;
277 }
278
279 return 0;
280}
281
282static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
283{
284 return task_work_pending(current) || !wq_list_empty(&ctx->work_llist);
285}
286
287static inline int io_run_task_work_ctx(struct io_ring_ctx *ctx)
288{
289 int ret = 0;
290 int ret2;
291
292 if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
293 ret = io_run_local_work(ctx);
294
295 /* want to run this after in case more is added */
296 ret2 = io_run_task_work();
297
298 /* Try propagate error in favour of if tasks were run,
299 * but still make sure to run them if requested
300 */
301 if (ret >= 0)
302 ret += ret2;
303
304 return ret;
305}
306
307static inline int io_run_local_work_locked(struct io_ring_ctx *ctx)
308{
309 bool locked;
310 int ret;
311
312 if (llist_empty(&ctx->work_llist))
313 return 0;
314
315 locked = true;
316 ret = __io_run_local_work(ctx, &locked);
317 /* shouldn't happen! */
318 if (WARN_ON_ONCE(!locked))
319 mutex_lock(&ctx->uring_lock);
320 return ret;
321}
322
323static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
324{
325 if (!*locked) {
326 mutex_lock(&ctx->uring_lock);
327 *locked = true;
328 }
329}
330
331/*
332 * Don't complete immediately but use deferred completion infrastructure.
333 * Protected by ->uring_lock and can only be used either with
334 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
335 */
336static inline void io_req_complete_defer(struct io_kiocb *req)
337 __must_hold(&req->ctx->uring_lock)
338{
339 struct io_submit_state *state = &req->ctx->submit_state;
340
341 lockdep_assert_held(&req->ctx->uring_lock);
342
343 wq_list_add_tail(&req->comp_list, &state->compl_reqs);
344}
345
346static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
347{
348 if (unlikely(ctx->off_timeout_used || ctx->drain_active || ctx->has_evfd))
349 __io_commit_cqring_flush(ctx);
350}
351
352/* must to be called somewhat shortly after putting a request */
353static inline void io_put_task(struct task_struct *task, int nr)
354{
355 if (likely(task == current))
356 task->io_uring->cached_refs += nr;
357 else
358 __io_put_task(task, nr);
359}
360
361static inline void io_get_task_refs(int nr)
362{
363 struct io_uring_task *tctx = current->io_uring;
364
365 tctx->cached_refs -= nr;
366 if (unlikely(tctx->cached_refs < 0))
367 io_task_refs_refill(tctx);
368}
369
370static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
371{
372 return !ctx->submit_state.free_list.next;
373}
374
375static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
376{
377 if (unlikely(io_req_cache_empty(ctx)))
378 return __io_alloc_req_refill(ctx);
379 return true;
380}
381
382static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
383{
384 struct io_wq_work_node *node;
385
386 node = wq_stack_extract(&ctx->submit_state.free_list);
387 return container_of(node, struct io_kiocb, comp_list);
388}
389
390static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
391{
392 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) ||
393 ctx->submitter_task == current);
394}
395
396static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
397{
398 io_req_set_res(req, res, 0);
399 req->io_task_work.func = io_req_task_complete;
400 io_req_task_work_add(req);
401}
402
403#endif