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>
12 #include "filetable.h"
14 #ifndef CREATE_TRACE_POINTS
15 #include <trace/events/io_uring.h>
20 IOU_ISSUE_SKIP_COMPLETE
= -EIOCBQUEUED
,
23 * Requeue the task_work to restart operations on this request. The
24 * actual value isn't important, should just be not an otherwise
25 * valid error code, yet less than -MAX_ERRNO and valid internally.
30 * Intended only when both IO_URING_F_MULTISHOT is passed
31 * to indicate to the poll runner that multishot should be
32 * removed and the result is set on req->cqe.res.
34 IOU_STOP_MULTISHOT
= -ECANCELED
,
37 bool io_cqe_cache_refill(struct io_ring_ctx
*ctx
, bool overflow
);
38 void io_req_cqe_overflow(struct io_kiocb
*req
);
39 int io_run_task_work_sig(struct io_ring_ctx
*ctx
);
40 void io_req_defer_failed(struct io_kiocb
*req
, s32 res
);
41 void io_req_complete_post(struct io_kiocb
*req
, unsigned issue_flags
);
42 bool io_post_aux_cqe(struct io_ring_ctx
*ctx
, u64 user_data
, s32 res
, u32 cflags
);
43 bool io_fill_cqe_req_aux(struct io_kiocb
*req
, bool defer
, s32 res
, u32 cflags
);
44 void __io_commit_cqring_flush(struct io_ring_ctx
*ctx
);
46 struct page
**io_pin_pages(unsigned long ubuf
, unsigned long len
, int *npages
);
48 struct file
*io_file_get_normal(struct io_kiocb
*req
, int fd
);
49 struct file
*io_file_get_fixed(struct io_kiocb
*req
, int fd
,
50 unsigned issue_flags
);
52 void __io_req_task_work_add(struct io_kiocb
*req
, unsigned flags
);
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
, struct io_tw_state
*ts_dont_use
);
56 void io_req_task_complete(struct io_kiocb
*req
, struct io_tw_state
*ts
);
57 void io_req_task_queue_fail(struct io_kiocb
*req
, int ret
);
58 void io_req_task_submit(struct io_kiocb
*req
, struct io_tw_state
*ts
);
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
);
64 int io_ring_add_registered_file(struct io_uring_task
*tctx
, struct file
*file
,
67 int io_poll_issue(struct io_kiocb
*req
, struct io_tw_state
*ts
);
68 int io_submit_sqes(struct io_ring_ctx
*ctx
, unsigned int nr
);
69 int io_do_iopoll(struct io_ring_ctx
*ctx
, bool force_nonspin
);
70 void __io_submit_flush_completions(struct io_ring_ctx
*ctx
);
71 int io_req_prep_async(struct io_kiocb
*req
);
73 struct io_wq_work
*io_wq_free_work(struct io_wq_work
*work
);
74 void io_wq_submit_work(struct io_wq_work
*work
);
76 void io_free_req(struct io_kiocb
*req
);
77 void io_queue_next(struct io_kiocb
*req
);
78 void io_task_refs_refill(struct io_uring_task
*tctx
);
79 bool __io_alloc_req_refill(struct io_ring_ctx
*ctx
);
81 bool io_match_task_safe(struct io_kiocb
*head
, struct task_struct
*task
,
84 void *io_mem_alloc(size_t size
);
85 void io_mem_free(void *ptr
);
88 IO_EVENTFD_OP_SIGNAL_BIT
,
89 IO_EVENTFD_OP_FREE_BIT
,
92 void io_eventfd_ops(struct rcu_head
*rcu
);
93 void io_activate_pollwq(struct io_ring_ctx
*ctx
);
95 #if defined(CONFIG_PROVE_LOCKING)
96 static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx
*ctx
)
98 lockdep_assert(in_task());
100 if (ctx
->flags
& IORING_SETUP_IOPOLL
) {
101 lockdep_assert_held(&ctx
->uring_lock
);
102 } else if (!ctx
->task_complete
) {
103 lockdep_assert_held(&ctx
->completion_lock
);
104 } else if (ctx
->submitter_task
) {
106 * ->submitter_task may be NULL and we can still post a CQE,
107 * if the ring has been setup with IORING_SETUP_R_DISABLED.
108 * Not from an SQE, as those cannot be submitted, but via
109 * updating tagged resources.
111 if (ctx
->submitter_task
->flags
& PF_EXITING
)
112 lockdep_assert(current_work());
114 lockdep_assert(current
== ctx
->submitter_task
);
118 static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx
*ctx
)
123 static inline void io_req_task_work_add(struct io_kiocb
*req
)
125 __io_req_task_work_add(req
, 0);
128 #define io_for_each_link(pos, head) \
129 for (pos = (head); pos; pos = pos->link)
131 static inline bool io_get_cqe_overflow(struct io_ring_ctx
*ctx
,
132 struct io_uring_cqe
**ret
,
135 io_lockdep_assert_cq_locked(ctx
);
137 if (unlikely(ctx
->cqe_cached
>= ctx
->cqe_sentinel
)) {
138 if (unlikely(!io_cqe_cache_refill(ctx
, overflow
)))
141 *ret
= ctx
->cqe_cached
;
142 ctx
->cached_cq_tail
++;
144 if (ctx
->flags
& IORING_SETUP_CQE32
)
149 static inline bool io_get_cqe(struct io_ring_ctx
*ctx
, struct io_uring_cqe
**ret
)
151 return io_get_cqe_overflow(ctx
, ret
, false);
154 static __always_inline
bool io_fill_cqe_req(struct io_ring_ctx
*ctx
,
155 struct io_kiocb
*req
)
157 struct io_uring_cqe
*cqe
;
160 * If we can't get a cq entry, userspace overflowed the
161 * submission (by quite a lot). Increment the overflow count in
164 if (unlikely(!io_get_cqe(ctx
, &cqe
)))
167 if (trace_io_uring_complete_enabled())
168 trace_io_uring_complete(req
->ctx
, req
, req
->cqe
.user_data
,
169 req
->cqe
.res
, req
->cqe
.flags
,
170 req
->big_cqe
.extra1
, req
->big_cqe
.extra2
);
172 memcpy(cqe
, &req
->cqe
, sizeof(*cqe
));
173 if (ctx
->flags
& IORING_SETUP_CQE32
) {
174 memcpy(cqe
->big_cqe
, &req
->big_cqe
, sizeof(*cqe
));
175 memset(&req
->big_cqe
, 0, sizeof(req
->big_cqe
));
180 static inline void req_set_fail(struct io_kiocb
*req
)
182 req
->flags
|= REQ_F_FAIL
;
183 if (req
->flags
& REQ_F_CQE_SKIP
) {
184 req
->flags
&= ~REQ_F_CQE_SKIP
;
185 req
->flags
|= REQ_F_SKIP_LINK_CQES
;
189 static inline void io_req_set_res(struct io_kiocb
*req
, s32 res
, u32 cflags
)
192 req
->cqe
.flags
= cflags
;
195 static inline bool req_has_async_data(struct io_kiocb
*req
)
197 return req
->flags
& REQ_F_ASYNC_DATA
;
200 static inline void io_put_file(struct io_kiocb
*req
)
202 if (!(req
->flags
& REQ_F_FIXED_FILE
) && req
->file
)
206 static inline void io_ring_submit_unlock(struct io_ring_ctx
*ctx
,
207 unsigned issue_flags
)
209 lockdep_assert_held(&ctx
->uring_lock
);
210 if (issue_flags
& IO_URING_F_UNLOCKED
)
211 mutex_unlock(&ctx
->uring_lock
);
214 static inline void io_ring_submit_lock(struct io_ring_ctx
*ctx
,
215 unsigned issue_flags
)
218 * "Normal" inline submissions always hold the uring_lock, since we
219 * grab it from the system call. Same is true for the SQPOLL offload.
220 * The only exception is when we've detached the request and issue it
221 * from an async worker thread, grab the lock for that case.
223 if (issue_flags
& IO_URING_F_UNLOCKED
)
224 mutex_lock(&ctx
->uring_lock
);
225 lockdep_assert_held(&ctx
->uring_lock
);
228 static inline void io_commit_cqring(struct io_ring_ctx
*ctx
)
230 /* order cqe stores with ring update */
231 smp_store_release(&ctx
->rings
->cq
.tail
, ctx
->cached_cq_tail
);
234 static inline void io_poll_wq_wake(struct io_ring_ctx
*ctx
)
236 if (wq_has_sleeper(&ctx
->poll_wq
))
237 __wake_up(&ctx
->poll_wq
, TASK_NORMAL
, 0,
238 poll_to_key(EPOLL_URING_WAKE
| EPOLLIN
));
241 static inline void io_cqring_wake(struct io_ring_ctx
*ctx
)
244 * Trigger waitqueue handler on all waiters on our waitqueue. This
245 * won't necessarily wake up all the tasks, io_should_wake() will make
248 * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter
249 * set in the mask so that if we recurse back into our own poll
250 * waitqueue handlers, we know we have a dependency between eventfd or
251 * epoll and should terminate multishot poll at that point.
253 if (wq_has_sleeper(&ctx
->cq_wait
))
254 __wake_up(&ctx
->cq_wait
, TASK_NORMAL
, 0,
255 poll_to_key(EPOLL_URING_WAKE
| EPOLLIN
));
258 static inline bool io_sqring_full(struct io_ring_ctx
*ctx
)
260 struct io_rings
*r
= ctx
->rings
;
262 return READ_ONCE(r
->sq
.tail
) - ctx
->cached_sq_head
== ctx
->sq_entries
;
265 static inline unsigned int io_sqring_entries(struct io_ring_ctx
*ctx
)
267 struct io_rings
*rings
= ctx
->rings
;
268 unsigned int entries
;
270 /* make sure SQ entry isn't read before tail */
271 entries
= smp_load_acquire(&rings
->sq
.tail
) - ctx
->cached_sq_head
;
272 return min(entries
, ctx
->sq_entries
);
275 static inline int io_run_task_work(void)
278 * Always check-and-clear the task_work notification signal. With how
279 * signaling works for task_work, we can find it set with nothing to
280 * run. We need to clear it for that case, like get_signal() does.
282 if (test_thread_flag(TIF_NOTIFY_SIGNAL
))
283 clear_notify_signal();
285 * PF_IO_WORKER never returns to userspace, so check here if we have
286 * notify work that needs processing.
288 if (current
->flags
& PF_IO_WORKER
&&
289 test_thread_flag(TIF_NOTIFY_RESUME
)) {
290 __set_current_state(TASK_RUNNING
);
291 resume_user_mode_work(NULL
);
293 if (task_work_pending(current
)) {
294 __set_current_state(TASK_RUNNING
);
302 static inline bool io_task_work_pending(struct io_ring_ctx
*ctx
)
304 return task_work_pending(current
) || !wq_list_empty(&ctx
->work_llist
);
307 static inline void io_tw_lock(struct io_ring_ctx
*ctx
, struct io_tw_state
*ts
)
310 mutex_lock(&ctx
->uring_lock
);
316 * Don't complete immediately but use deferred completion infrastructure.
317 * Protected by ->uring_lock and can only be used either with
318 * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
320 static inline void io_req_complete_defer(struct io_kiocb
*req
)
321 __must_hold(&req
->ctx
->uring_lock
)
323 struct io_submit_state
*state
= &req
->ctx
->submit_state
;
325 lockdep_assert_held(&req
->ctx
->uring_lock
);
327 wq_list_add_tail(&req
->comp_list
, &state
->compl_reqs
);
330 static inline void io_commit_cqring_flush(struct io_ring_ctx
*ctx
)
332 if (unlikely(ctx
->off_timeout_used
|| ctx
->drain_active
||
333 ctx
->has_evfd
|| ctx
->poll_activated
))
334 __io_commit_cqring_flush(ctx
);
337 static inline void io_get_task_refs(int nr
)
339 struct io_uring_task
*tctx
= current
->io_uring
;
341 tctx
->cached_refs
-= nr
;
342 if (unlikely(tctx
->cached_refs
< 0))
343 io_task_refs_refill(tctx
);
346 static inline bool io_req_cache_empty(struct io_ring_ctx
*ctx
)
348 return !ctx
->submit_state
.free_list
.next
;
351 extern struct kmem_cache
*req_cachep
;
352 extern struct kmem_cache
*io_buf_cachep
;
354 static inline struct io_kiocb
*io_extract_req(struct io_ring_ctx
*ctx
)
356 struct io_kiocb
*req
;
358 req
= container_of(ctx
->submit_state
.free_list
.next
, struct io_kiocb
, comp_list
);
359 wq_stack_extract(&ctx
->submit_state
.free_list
);
363 static inline bool io_alloc_req(struct io_ring_ctx
*ctx
, struct io_kiocb
**req
)
365 if (unlikely(io_req_cache_empty(ctx
))) {
366 if (!__io_alloc_req_refill(ctx
))
369 *req
= io_extract_req(ctx
);
373 static inline bool io_allowed_defer_tw_run(struct io_ring_ctx
*ctx
)
375 return likely(ctx
->submitter_task
== current
);
378 static inline bool io_allowed_run_tw(struct io_ring_ctx
*ctx
)
380 return likely(!(ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
) ||
381 ctx
->submitter_task
== current
);
384 static inline void io_req_queue_tw_complete(struct io_kiocb
*req
, s32 res
)
386 io_req_set_res(req
, res
, 0);
387 req
->io_task_work
.func
= io_req_task_complete
;
388 io_req_task_work_add(req
);
392 * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each
395 static inline size_t uring_sqe_size(struct io_ring_ctx
*ctx
)
397 if (ctx
->flags
& IORING_SETUP_SQE128
)
398 return 2 * sizeof(struct io_uring_sqe
);
399 return sizeof(struct io_uring_sqe
);