4 #include <linux/errno.h>
5 #include <linux/lockdep.h>
6 #include <linux/io_uring_types.h>
7 #include <uapi/linux/eventpoll.h>
10 #include "filetable.h"
12 #ifndef CREATE_TRACE_POINTS
13 #include <trace/events/io_uring.h>
18 IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED,
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.
25 IOU_STOP_MULTISHOT = -ECANCELED,
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 void io_req_defer_failed(struct io_kiocb *req, s32 res);
32 void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags);
33 bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags);
34 bool io_aux_cqe(struct io_ring_ctx *ctx, bool defer, u64 user_data, s32 res, u32 cflags,
36 void __io_commit_cqring_flush(struct io_ring_ctx *ctx);
38 struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages);
40 struct file *io_file_get_normal(struct io_kiocb *req, int fd);
41 struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
42 unsigned issue_flags);
44 static inline bool io_req_ffs_set(struct io_kiocb *req)
46 return req->flags & REQ_F_FIXED_FILE;
49 void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
50 bool io_is_uring_fops(struct file *file);
51 bool io_alloc_async_data(struct io_kiocb *req);
52 void io_req_task_queue(struct io_kiocb *req);
53 void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
54 void io_req_task_complete(struct io_kiocb *req, bool *locked);
55 void io_req_task_queue_fail(struct io_kiocb *req, int ret);
56 void io_req_task_submit(struct io_kiocb *req, bool *locked);
57 void tctx_task_work(struct callback_head *cb);
58 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
59 int io_uring_alloc_task_context(struct task_struct *task,
60 struct io_ring_ctx *ctx);
62 int io_poll_issue(struct io_kiocb *req, bool *locked);
63 int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
64 int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
65 void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
66 int io_req_prep_async(struct io_kiocb *req);
68 struct io_wq_work *io_wq_free_work(struct io_wq_work *work);
69 void io_wq_submit_work(struct io_wq_work *work);
71 void io_free_req(struct io_kiocb *req);
72 void io_queue_next(struct io_kiocb *req);
73 void __io_put_task(struct task_struct *task, int nr);
74 void io_task_refs_refill(struct io_uring_task *tctx);
75 bool __io_alloc_req_refill(struct io_ring_ctx *ctx);
77 bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
80 #define io_lockdep_assert_cq_locked(ctx) \
82 if (ctx->flags & IORING_SETUP_IOPOLL) { \
83 lockdep_assert_held(&ctx->uring_lock); \
84 } else if (!ctx->task_complete) { \
85 lockdep_assert_held(&ctx->completion_lock); \
86 } else if (ctx->submitter_task->flags & PF_EXITING) { \
87 lockdep_assert(current_work()); \
89 lockdep_assert(current == ctx->submitter_task); \
93 static inline void io_req_task_work_add(struct io_kiocb *req)
95 __io_req_task_work_add(req, true);
98 #define io_for_each_link(pos, head) \
99 for (pos = (head); pos; pos = pos->link)
101 void io_cq_unlock_post(struct io_ring_ctx *ctx);
103 static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx,
106 io_lockdep_assert_cq_locked(ctx);
108 if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
109 struct io_uring_cqe *cqe = ctx->cqe_cached;
111 ctx->cached_cq_tail++;
113 if (ctx->flags & IORING_SETUP_CQE32)
118 return __io_get_cqe(ctx, overflow);
121 static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
123 return io_get_cqe_overflow(ctx, false);
126 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
127 struct io_kiocb *req)
129 struct io_uring_cqe *cqe;
132 * If we can't get a cq entry, userspace overflowed the
133 * submission (by quite a lot). Increment the overflow count in
136 cqe = io_get_cqe(ctx);
140 trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
141 req->cqe.res, req->cqe.flags,
142 (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0,
143 (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0);
145 memcpy(cqe, &req->cqe, sizeof(*cqe));
147 if (ctx->flags & IORING_SETUP_CQE32) {
148 u64 extra1 = 0, extra2 = 0;
150 if (req->flags & REQ_F_CQE32_INIT) {
151 extra1 = req->extra1;
152 extra2 = req->extra2;
155 WRITE_ONCE(cqe->big_cqe[0], extra1);
156 WRITE_ONCE(cqe->big_cqe[1], extra2);
161 static inline bool io_fill_cqe_req(struct io_ring_ctx *ctx,
162 struct io_kiocb *req)
164 if (likely(__io_fill_cqe_req(ctx, req)))
166 return io_req_cqe_overflow(req);
169 static inline void req_set_fail(struct io_kiocb *req)
171 req->flags |= REQ_F_FAIL;
172 if (req->flags & REQ_F_CQE_SKIP) {
173 req->flags &= ~REQ_F_CQE_SKIP;
174 req->flags |= REQ_F_SKIP_LINK_CQES;
178 static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
181 req->cqe.flags = cflags;
184 static inline bool req_has_async_data(struct io_kiocb *req)
186 return req->flags & REQ_F_ASYNC_DATA;
189 static inline void io_put_file(struct file *file)
195 static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx,
196 unsigned issue_flags)
198 lockdep_assert_held(&ctx->uring_lock);
199 if (issue_flags & IO_URING_F_UNLOCKED)
200 mutex_unlock(&ctx->uring_lock);
203 static inline void io_ring_submit_lock(struct io_ring_ctx *ctx,
204 unsigned issue_flags)
207 * "Normal" inline submissions always hold the uring_lock, since we
208 * grab it from the system call. Same is true for the SQPOLL offload.
209 * The only exception is when we've detached the request and issue it
210 * from an async worker thread, grab the lock for that case.
212 if (issue_flags & IO_URING_F_UNLOCKED)
213 mutex_lock(&ctx->uring_lock);
214 lockdep_assert_held(&ctx->uring_lock);
217 static inline void io_commit_cqring(struct io_ring_ctx *ctx)
219 /* order cqe stores with ring update */
220 smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
223 static inline void io_poll_wq_wake(struct io_ring_ctx *ctx)
225 if (wq_has_sleeper(&ctx->poll_wq))
226 __wake_up(&ctx->poll_wq, TASK_NORMAL, 0,
227 poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
230 /* requires smb_mb() prior, see wq_has_sleeper() */
231 static inline void __io_cqring_wake(struct io_ring_ctx *ctx)
234 * Trigger waitqueue handler on all waiters on our waitqueue. This
235 * won't necessarily wake up all the tasks, io_should_wake() will make
238 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter
239 * set in the mask so that if we recurse back into our own poll
240 * waitqueue handlers, we know we have a dependency between eventfd or
241 * epoll and should terminate multishot poll at that point.
243 if (waitqueue_active(&ctx->cq_wait))
244 __wake_up(&ctx->cq_wait, TASK_NORMAL, 0,
245 poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
248 static inline void io_cqring_wake(struct io_ring_ctx *ctx)
251 __io_cqring_wake(ctx);
254 static inline bool io_sqring_full(struct io_ring_ctx *ctx)
256 struct io_rings *r = ctx->rings;
258 return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
261 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
263 struct io_rings *rings = ctx->rings;
265 /* make sure SQ entry isn't read before tail */
266 return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
269 static inline int io_run_task_work(void)
272 * Always check-and-clear the task_work notification signal. With how
273 * signaling works for task_work, we can find it set with nothing to
274 * run. We need to clear it for that case, like get_signal() does.
276 if (test_thread_flag(TIF_NOTIFY_SIGNAL))
277 clear_notify_signal();
278 if (task_work_pending(current)) {
279 __set_current_state(TASK_RUNNING);
287 static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
289 return task_work_pending(current) || !wq_list_empty(&ctx->work_llist);
292 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
295 mutex_lock(&ctx->uring_lock);
301 * Don't complete immediately but use deferred completion infrastructure.
302 * Protected by ->uring_lock and can only be used either with
303 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
305 static inline void io_req_complete_defer(struct io_kiocb *req)
306 __must_hold(&req->ctx->uring_lock)
308 struct io_submit_state *state = &req->ctx->submit_state;
310 lockdep_assert_held(&req->ctx->uring_lock);
312 wq_list_add_tail(&req->comp_list, &state->compl_reqs);
315 static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
317 if (unlikely(ctx->off_timeout_used || ctx->drain_active ||
318 ctx->has_evfd || ctx->poll_activated))
319 __io_commit_cqring_flush(ctx);
322 /* must to be called somewhat shortly after putting a request */
323 static inline void io_put_task(struct task_struct *task, int nr)
325 if (likely(task == current))
326 task->io_uring->cached_refs += nr;
328 __io_put_task(task, nr);
331 static inline void io_get_task_refs(int nr)
333 struct io_uring_task *tctx = current->io_uring;
335 tctx->cached_refs -= nr;
336 if (unlikely(tctx->cached_refs < 0))
337 io_task_refs_refill(tctx);
340 static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
342 return !ctx->submit_state.free_list.next;
345 static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
347 if (unlikely(io_req_cache_empty(ctx)))
348 return __io_alloc_req_refill(ctx);
352 static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
354 struct io_wq_work_node *node;
356 node = wq_stack_extract(&ctx->submit_state.free_list);
357 return container_of(node, struct io_kiocb, comp_list);
360 static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx)
362 return likely(ctx->submitter_task == current);
365 static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
367 return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) ||
368 ctx->submitter_task == current);
371 static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
373 io_req_set_res(req, res, 0);
374 req->io_task_work.func = io_req_task_complete;
375 io_req_task_work_add(req);