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329061d3 JA |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/kernel.h> | |
3 | #include <linux/errno.h> | |
4 | #include <linux/fs.h> | |
5 | #include <linux/file.h> | |
6 | #include <linux/mm.h> | |
7 | #include <linux/slab.h> | |
8 | #include <linux/poll.h> | |
9 | #include <linux/hashtable.h> | |
10 | #include <linux/io_uring.h> | |
11 | ||
12 | #include <trace/events/io_uring.h> | |
13 | ||
14 | #include <uapi/linux/io_uring.h> | |
15 | ||
329061d3 JA |
16 | #include "io_uring.h" |
17 | #include "refs.h" | |
18 | #include "opdef.h" | |
3b77495a | 19 | #include "kbuf.h" |
329061d3 | 20 | #include "poll.h" |
38513c46 | 21 | #include "cancel.h" |
329061d3 JA |
22 | |
23 | struct io_poll_update { | |
24 | struct file *file; | |
25 | u64 old_user_data; | |
26 | u64 new_user_data; | |
27 | __poll_t events; | |
28 | bool update_events; | |
29 | bool update_user_data; | |
30 | }; | |
31 | ||
32 | struct io_poll_table { | |
33 | struct poll_table_struct pt; | |
34 | struct io_kiocb *req; | |
35 | int nr_entries; | |
36 | int error; | |
49f1c68e | 37 | bool owning; |
063a0079 PB |
38 | /* output value, set only if arm poll returns >0 */ |
39 | __poll_t result_mask; | |
329061d3 JA |
40 | }; |
41 | ||
42 | #define IO_POLL_CANCEL_FLAG BIT(31) | |
a26a35e9 PB |
43 | #define IO_POLL_RETRY_FLAG BIT(30) |
44 | #define IO_POLL_REF_MASK GENMASK(29, 0) | |
45 | ||
46 | /* | |
47 | * We usually have 1-2 refs taken, 128 is more than enough and we want to | |
48 | * maximise the margin between this amount and the moment when it overflows. | |
49 | */ | |
50 | #define IO_POLL_REF_BIAS 128 | |
329061d3 | 51 | |
0638cd7b PB |
52 | #define IO_WQE_F_DOUBLE 1 |
53 | ||
1947ddf9 JA |
54 | static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, |
55 | void *key); | |
56 | ||
0638cd7b PB |
57 | static inline struct io_kiocb *wqe_to_req(struct wait_queue_entry *wqe) |
58 | { | |
59 | unsigned long priv = (unsigned long)wqe->private; | |
60 | ||
61 | return (struct io_kiocb *)(priv & ~IO_WQE_F_DOUBLE); | |
62 | } | |
63 | ||
64 | static inline bool wqe_is_double(struct wait_queue_entry *wqe) | |
65 | { | |
66 | unsigned long priv = (unsigned long)wqe->private; | |
67 | ||
68 | return priv & IO_WQE_F_DOUBLE; | |
69 | } | |
70 | ||
a26a35e9 PB |
71 | static bool io_poll_get_ownership_slowpath(struct io_kiocb *req) |
72 | { | |
73 | int v; | |
74 | ||
75 | /* | |
76 | * poll_refs are already elevated and we don't have much hope for | |
77 | * grabbing the ownership. Instead of incrementing set a retry flag | |
78 | * to notify the loop that there might have been some change. | |
79 | */ | |
80 | v = atomic_fetch_or(IO_POLL_RETRY_FLAG, &req->poll_refs); | |
81 | if (v & IO_POLL_REF_MASK) | |
82 | return false; | |
83 | return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK); | |
84 | } | |
85 | ||
329061d3 JA |
86 | /* |
87 | * If refs part of ->poll_refs (see IO_POLL_REF_MASK) is 0, it's free. We can | |
88 | * bump it and acquire ownership. It's disallowed to modify requests while not | |
89 | * owning it, that prevents from races for enqueueing task_work's and b/w | |
90 | * arming poll and wakeups. | |
91 | */ | |
92 | static inline bool io_poll_get_ownership(struct io_kiocb *req) | |
93 | { | |
a26a35e9 PB |
94 | if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) |
95 | return io_poll_get_ownership_slowpath(req); | |
329061d3 JA |
96 | return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK); |
97 | } | |
98 | ||
99 | static void io_poll_mark_cancelled(struct io_kiocb *req) | |
100 | { | |
101 | atomic_or(IO_POLL_CANCEL_FLAG, &req->poll_refs); | |
102 | } | |
103 | ||
104 | static struct io_poll *io_poll_get_double(struct io_kiocb *req) | |
105 | { | |
106 | /* pure poll stashes this in ->async_data, poll driven retry elsewhere */ | |
107 | if (req->opcode == IORING_OP_POLL_ADD) | |
108 | return req->async_data; | |
109 | return req->apoll->double_poll; | |
110 | } | |
111 | ||
112 | static struct io_poll *io_poll_get_single(struct io_kiocb *req) | |
113 | { | |
114 | if (req->opcode == IORING_OP_POLL_ADD) | |
f2ccb5ae | 115 | return io_kiocb_to_cmd(req, struct io_poll); |
329061d3 JA |
116 | return &req->apoll->poll; |
117 | } | |
118 | ||
119 | static void io_poll_req_insert(struct io_kiocb *req) | |
120 | { | |
e6f89be6 PB |
121 | struct io_hash_table *table = &req->ctx->cancel_table; |
122 | u32 index = hash_long(req->cqe.user_data, table->hash_bits); | |
123 | struct io_hash_bucket *hb = &table->hbs[index]; | |
329061d3 | 124 | |
38513c46 HX |
125 | spin_lock(&hb->lock); |
126 | hlist_add_head(&req->hash_node, &hb->list); | |
127 | spin_unlock(&hb->lock); | |
128 | } | |
129 | ||
130 | static void io_poll_req_delete(struct io_kiocb *req, struct io_ring_ctx *ctx) | |
131 | { | |
e6f89be6 PB |
132 | struct io_hash_table *table = &req->ctx->cancel_table; |
133 | u32 index = hash_long(req->cqe.user_data, table->hash_bits); | |
134 | spinlock_t *lock = &table->hbs[index].lock; | |
38513c46 HX |
135 | |
136 | spin_lock(lock); | |
137 | hash_del(&req->hash_node); | |
138 | spin_unlock(lock); | |
329061d3 JA |
139 | } |
140 | ||
9ca9fb24 PB |
141 | static void io_poll_req_insert_locked(struct io_kiocb *req) |
142 | { | |
143 | struct io_hash_table *table = &req->ctx->cancel_table_locked; | |
144 | u32 index = hash_long(req->cqe.user_data, table->hash_bits); | |
145 | ||
5576035f PB |
146 | lockdep_assert_held(&req->ctx->uring_lock); |
147 | ||
9ca9fb24 PB |
148 | hlist_add_head(&req->hash_node, &table->hbs[index].list); |
149 | } | |
150 | ||
a282967c | 151 | static void io_poll_tw_hash_eject(struct io_kiocb *req, struct io_tw_state *ts) |
9ca9fb24 PB |
152 | { |
153 | struct io_ring_ctx *ctx = req->ctx; | |
154 | ||
155 | if (req->flags & REQ_F_HASH_LOCKED) { | |
156 | /* | |
157 | * ->cancel_table_locked is protected by ->uring_lock in | |
158 | * contrast to per bucket spinlocks. Likely, tctx_task_work() | |
159 | * already grabbed the mutex for us, but there is a chance it | |
160 | * failed. | |
161 | */ | |
a282967c | 162 | io_tw_lock(ctx, ts); |
9ca9fb24 | 163 | hash_del(&req->hash_node); |
b21a51e2 | 164 | req->flags &= ~REQ_F_HASH_LOCKED; |
9ca9fb24 PB |
165 | } else { |
166 | io_poll_req_delete(req, ctx); | |
167 | } | |
168 | } | |
169 | ||
1947ddf9 | 170 | static void io_init_poll_iocb(struct io_poll *poll, __poll_t events) |
329061d3 JA |
171 | { |
172 | poll->head = NULL; | |
173 | #define IO_POLL_UNMASK (EPOLLERR|EPOLLHUP|EPOLLNVAL|EPOLLRDHUP) | |
174 | /* mask in events that we always want/need */ | |
175 | poll->events = events | IO_POLL_UNMASK; | |
176 | INIT_LIST_HEAD(&poll->wait.entry); | |
1947ddf9 | 177 | init_waitqueue_func_entry(&poll->wait, io_poll_wake); |
329061d3 JA |
178 | } |
179 | ||
180 | static inline void io_poll_remove_entry(struct io_poll *poll) | |
181 | { | |
182 | struct wait_queue_head *head = smp_load_acquire(&poll->head); | |
183 | ||
184 | if (head) { | |
185 | spin_lock_irq(&head->lock); | |
186 | list_del_init(&poll->wait.entry); | |
187 | poll->head = NULL; | |
188 | spin_unlock_irq(&head->lock); | |
189 | } | |
190 | } | |
191 | ||
192 | static void io_poll_remove_entries(struct io_kiocb *req) | |
193 | { | |
194 | /* | |
195 | * Nothing to do if neither of those flags are set. Avoid dipping | |
196 | * into the poll/apoll/double cachelines if we can. | |
197 | */ | |
198 | if (!(req->flags & (REQ_F_SINGLE_POLL | REQ_F_DOUBLE_POLL))) | |
199 | return; | |
200 | ||
201 | /* | |
202 | * While we hold the waitqueue lock and the waitqueue is nonempty, | |
203 | * wake_up_pollfree() will wait for us. However, taking the waitqueue | |
204 | * lock in the first place can race with the waitqueue being freed. | |
205 | * | |
206 | * We solve this as eventpoll does: by taking advantage of the fact that | |
207 | * all users of wake_up_pollfree() will RCU-delay the actual free. If | |
208 | * we enter rcu_read_lock() and see that the pointer to the queue is | |
209 | * non-NULL, we can then lock it without the memory being freed out from | |
210 | * under us. | |
211 | * | |
212 | * Keep holding rcu_read_lock() as long as we hold the queue lock, in | |
213 | * case the caller deletes the entry from the queue, leaving it empty. | |
214 | * In that case, only RCU prevents the queue memory from being freed. | |
215 | */ | |
216 | rcu_read_lock(); | |
217 | if (req->flags & REQ_F_SINGLE_POLL) | |
218 | io_poll_remove_entry(io_poll_get_single(req)); | |
219 | if (req->flags & REQ_F_DOUBLE_POLL) | |
220 | io_poll_remove_entry(io_poll_get_double(req)); | |
221 | rcu_read_unlock(); | |
222 | } | |
223 | ||
2ba69707 DY |
224 | enum { |
225 | IOU_POLL_DONE = 0, | |
226 | IOU_POLL_NO_ACTION = 1, | |
114eccdf | 227 | IOU_POLL_REMOVE_POLL_USE_RES = 2, |
6e5aedb9 | 228 | IOU_POLL_REISSUE = 3, |
2ba69707 DY |
229 | }; |
230 | ||
329061d3 JA |
231 | /* |
232 | * All poll tw should go through this. Checks for poll events, manages | |
233 | * references, does rewait, etc. | |
234 | * | |
6e5aedb9 JA |
235 | * Returns a negative error on failure. IOU_POLL_NO_ACTION when no action |
236 | * require, which is either spurious wakeup or multishot CQE is served. | |
237 | * IOU_POLL_DONE when it's done with the request, then the mask is stored in | |
238 | * req->cqe.res. IOU_POLL_REMOVE_POLL_USE_RES indicates to remove multishot | |
239 | * poll and that the result is stored in req->cqe. | |
329061d3 | 240 | */ |
a282967c | 241 | static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts) |
329061d3 | 242 | { |
6e5aedb9 | 243 | int v; |
329061d3 JA |
244 | |
245 | /* req->task == current here, checking PF_EXITING is safe */ | |
246 | if (unlikely(req->task->flags & PF_EXITING)) | |
247 | return -ECANCELED; | |
248 | ||
249 | do { | |
250 | v = atomic_read(&req->poll_refs); | |
251 | ||
9805fa2d PB |
252 | if (unlikely(v != 1)) { |
253 | /* tw should be the owner and so have some refs */ | |
254 | if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK))) | |
c3bfb57e | 255 | return IOU_POLL_NO_ACTION; |
9805fa2d PB |
256 | if (v & IO_POLL_CANCEL_FLAG) |
257 | return -ECANCELED; | |
a26a35e9 | 258 | /* |
9805fa2d PB |
259 | * cqe.res contains only events of the first wake up |
260 | * and all others are to be lost. Redo vfs_poll() to get | |
261 | * up to date state. | |
a26a35e9 | 262 | */ |
9805fa2d PB |
263 | if ((v & IO_POLL_REF_MASK) != 1) |
264 | req->cqe.res = 0; | |
265 | ||
266 | if (v & IO_POLL_RETRY_FLAG) { | |
267 | req->cqe.res = 0; | |
268 | /* | |
269 | * We won't find new events that came in between | |
270 | * vfs_poll and the ref put unless we clear the | |
271 | * flag in advance. | |
272 | */ | |
273 | atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs); | |
274 | v &= ~IO_POLL_RETRY_FLAG; | |
275 | } | |
a26a35e9 | 276 | } |
329061d3 | 277 | |
2ba69707 | 278 | /* the mask was stashed in __io_poll_execute */ |
329061d3 JA |
279 | if (!req->cqe.res) { |
280 | struct poll_table_struct pt = { ._key = req->apoll_events }; | |
281 | req->cqe.res = vfs_poll(req->file, &pt) & req->apoll_events; | |
6e5aedb9 JA |
282 | /* |
283 | * We got woken with a mask, but someone else got to | |
284 | * it first. The above vfs_poll() doesn't add us back | |
285 | * to the waitqueue, so if we get nothing back, we | |
286 | * should be safe and attempt a reissue. | |
287 | */ | |
8caa03f1 JA |
288 | if (unlikely(!req->cqe.res)) { |
289 | /* Multishot armed need not reissue */ | |
290 | if (!(req->apoll_events & EPOLLONESHOT)) | |
291 | continue; | |
6e5aedb9 | 292 | return IOU_POLL_REISSUE; |
8caa03f1 | 293 | } |
329061d3 | 294 | } |
329061d3 | 295 | if (req->apoll_events & EPOLLONESHOT) |
2ba69707 | 296 | return IOU_POLL_DONE; |
329061d3 JA |
297 | |
298 | /* multishot, just fill a CQE and proceed */ | |
299 | if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { | |
300 | __poll_t mask = mangle_poll(req->cqe.res & | |
301 | req->apoll_events); | |
329061d3 | 302 | |
b6b2bb58 PB |
303 | if (!io_fill_cqe_req_aux(req, ts->locked, mask, |
304 | IORING_CQE_F_MORE)) { | |
a2da6763 DY |
305 | io_req_set_res(req, mask, 0); |
306 | return IOU_POLL_REMOVE_POLL_USE_RES; | |
307 | } | |
d245bca6 | 308 | } else { |
a282967c | 309 | int ret = io_poll_issue(req, ts); |
114eccdf DY |
310 | if (ret == IOU_STOP_MULTISHOT) |
311 | return IOU_POLL_REMOVE_POLL_USE_RES; | |
2ba69707 | 312 | if (ret < 0) |
d245bca6 PB |
313 | return ret; |
314 | } | |
329061d3 | 315 | |
b98186ae PB |
316 | /* force the next iteration to vfs_poll() */ |
317 | req->cqe.res = 0; | |
318 | ||
329061d3 JA |
319 | /* |
320 | * Release all references, retry if someone tried to restart | |
321 | * task_work while we were executing it. | |
322 | */ | |
12ad3d2d LM |
323 | } while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs) & |
324 | IO_POLL_REF_MASK); | |
329061d3 | 325 | |
2ba69707 | 326 | return IOU_POLL_NO_ACTION; |
329061d3 JA |
327 | } |
328 | ||
c92fcfc2 | 329 | void io_poll_task_func(struct io_kiocb *req, struct io_tw_state *ts) |
329061d3 | 330 | { |
329061d3 JA |
331 | int ret; |
332 | ||
a282967c | 333 | ret = io_poll_check_events(req, ts); |
2ba69707 | 334 | if (ret == IOU_POLL_NO_ACTION) |
329061d3 | 335 | return; |
329061d3 | 336 | io_poll_remove_entries(req); |
a282967c | 337 | io_poll_tw_hash_eject(req, ts); |
9ca9fb24 | 338 | |
443e5755 PB |
339 | if (req->opcode == IORING_OP_POLL_ADD) { |
340 | if (ret == IOU_POLL_DONE) { | |
341 | struct io_poll *poll; | |
329061d3 | 342 | |
443e5755 PB |
343 | poll = io_kiocb_to_cmd(req, struct io_poll); |
344 | req->cqe.res = mangle_poll(req->cqe.res & poll->events); | |
6e5aedb9 | 345 | } else if (ret == IOU_POLL_REISSUE) { |
a282967c | 346 | io_req_task_submit(req, ts); |
6e5aedb9 | 347 | return; |
443e5755 PB |
348 | } else if (ret != IOU_POLL_REMOVE_POLL_USE_RES) { |
349 | req->cqe.res = ret; | |
350 | req_set_fail(req); | |
351 | } | |
329061d3 | 352 | |
443e5755 | 353 | io_req_set_res(req, req->cqe.res, 0); |
a282967c | 354 | io_req_task_complete(req, ts); |
443e5755 | 355 | } else { |
a282967c | 356 | io_tw_lock(req->ctx, ts); |
443e5755 PB |
357 | |
358 | if (ret == IOU_POLL_REMOVE_POLL_USE_RES) | |
a282967c | 359 | io_req_task_complete(req, ts); |
6e5aedb9 | 360 | else if (ret == IOU_POLL_DONE || ret == IOU_POLL_REISSUE) |
a282967c | 361 | io_req_task_submit(req, ts); |
443e5755 PB |
362 | else |
363 | io_req_defer_failed(req, ret); | |
364 | } | |
329061d3 JA |
365 | } |
366 | ||
13a99017 | 367 | static void __io_poll_execute(struct io_kiocb *req, int mask) |
329061d3 JA |
368 | { |
369 | io_req_set_res(req, mask, 0); | |
443e5755 | 370 | req->io_task_work.func = io_poll_task_func; |
329061d3 | 371 | |
48863ffd | 372 | trace_io_uring_task_add(req, mask); |
329061d3 JA |
373 | io_req_task_work_add(req); |
374 | } | |
375 | ||
13a99017 | 376 | static inline void io_poll_execute(struct io_kiocb *req, int res) |
329061d3 JA |
377 | { |
378 | if (io_poll_get_ownership(req)) | |
13a99017 | 379 | __io_poll_execute(req, res); |
329061d3 JA |
380 | } |
381 | ||
382 | static void io_poll_cancel_req(struct io_kiocb *req) | |
383 | { | |
384 | io_poll_mark_cancelled(req); | |
385 | /* kick tw, which should complete the request */ | |
13a99017 | 386 | io_poll_execute(req, 0); |
329061d3 JA |
387 | } |
388 | ||
329061d3 JA |
389 | #define IO_ASYNC_POLL_COMMON (EPOLLONESHOT | EPOLLPRI) |
390 | ||
fe991a76 JA |
391 | static __cold int io_pollfree_wake(struct io_kiocb *req, struct io_poll *poll) |
392 | { | |
393 | io_poll_mark_cancelled(req); | |
394 | /* we have to kick tw in case it's not already */ | |
395 | io_poll_execute(req, 0); | |
396 | ||
397 | /* | |
398 | * If the waitqueue is being freed early but someone is already | |
399 | * holds ownership over it, we have to tear down the request as | |
400 | * best we can. That means immediately removing the request from | |
401 | * its waitqueue and preventing all further accesses to the | |
402 | * waitqueue via the request. | |
403 | */ | |
404 | list_del_init(&poll->wait.entry); | |
405 | ||
406 | /* | |
407 | * Careful: this *must* be the last step, since as soon | |
408 | * as req->head is NULL'ed out, the request can be | |
409 | * completed and freed, since aio_poll_complete_work() | |
410 | * will no longer need to take the waitqueue lock. | |
411 | */ | |
412 | smp_store_release(&poll->head, NULL); | |
413 | return 1; | |
414 | } | |
415 | ||
329061d3 JA |
416 | static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, |
417 | void *key) | |
418 | { | |
419 | struct io_kiocb *req = wqe_to_req(wait); | |
420 | struct io_poll *poll = container_of(wait, struct io_poll, wait); | |
421 | __poll_t mask = key_to_poll(key); | |
422 | ||
fe991a76 JA |
423 | if (unlikely(mask & POLLFREE)) |
424 | return io_pollfree_wake(req, poll); | |
329061d3 JA |
425 | |
426 | /* for instances that support it check for an event match first */ | |
427 | if (mask && !(mask & (poll->events & ~IO_ASYNC_POLL_COMMON))) | |
428 | return 0; | |
429 | ||
430 | if (io_poll_get_ownership(req)) { | |
44648532 JA |
431 | /* |
432 | * If we trigger a multishot poll off our own wakeup path, | |
433 | * disable multishot as there is a circular dependency between | |
434 | * CQ posting and triggering the event. | |
435 | */ | |
436 | if (mask & EPOLL_URING_WAKE) | |
437 | poll->events |= EPOLLONESHOT; | |
438 | ||
329061d3 JA |
439 | /* optional, saves extra locking for removal in tw handler */ |
440 | if (mask && poll->events & EPOLLONESHOT) { | |
441 | list_del_init(&poll->wait.entry); | |
442 | poll->head = NULL; | |
443 | if (wqe_is_double(wait)) | |
444 | req->flags &= ~REQ_F_DOUBLE_POLL; | |
445 | else | |
446 | req->flags &= ~REQ_F_SINGLE_POLL; | |
447 | } | |
13a99017 | 448 | __io_poll_execute(req, mask); |
329061d3 JA |
449 | } |
450 | return 1; | |
451 | } | |
452 | ||
30a33669 PB |
453 | /* fails only when polling is already completing by the first entry */ |
454 | static bool io_poll_double_prepare(struct io_kiocb *req) | |
49f1c68e PB |
455 | { |
456 | struct wait_queue_head *head; | |
457 | struct io_poll *poll = io_poll_get_single(req); | |
458 | ||
459 | /* head is RCU protected, see io_poll_remove_entries() comments */ | |
460 | rcu_read_lock(); | |
461 | head = smp_load_acquire(&poll->head); | |
7a121ced | 462 | /* |
30a33669 PB |
463 | * poll arm might not hold ownership and so race for req->flags with |
464 | * io_poll_wake(). There is only one poll entry queued, serialise with | |
465 | * it by taking its head lock. As we're still arming the tw hanlder | |
466 | * is not going to be run, so there are no races with it. | |
7a121ced | 467 | */ |
30a33669 | 468 | if (head) { |
49f1c68e | 469 | spin_lock_irq(&head->lock); |
30a33669 PB |
470 | req->flags |= REQ_F_DOUBLE_POLL; |
471 | if (req->opcode == IORING_OP_POLL_ADD) | |
472 | req->flags |= REQ_F_ASYNC_DATA; | |
49f1c68e | 473 | spin_unlock_irq(&head->lock); |
30a33669 | 474 | } |
49f1c68e | 475 | rcu_read_unlock(); |
30a33669 | 476 | return !!head; |
49f1c68e PB |
477 | } |
478 | ||
329061d3 JA |
479 | static void __io_queue_proc(struct io_poll *poll, struct io_poll_table *pt, |
480 | struct wait_queue_head *head, | |
481 | struct io_poll **poll_ptr) | |
482 | { | |
483 | struct io_kiocb *req = pt->req; | |
484 | unsigned long wqe_private = (unsigned long) req; | |
485 | ||
486 | /* | |
487 | * The file being polled uses multiple waitqueues for poll handling | |
488 | * (e.g. one for read, one for write). Setup a separate io_poll | |
489 | * if this happens. | |
490 | */ | |
491 | if (unlikely(pt->nr_entries)) { | |
492 | struct io_poll *first = poll; | |
493 | ||
494 | /* double add on the same waitqueue head, ignore */ | |
495 | if (first->head == head) | |
496 | return; | |
497 | /* already have a 2nd entry, fail a third attempt */ | |
498 | if (*poll_ptr) { | |
499 | if ((*poll_ptr)->head == head) | |
500 | return; | |
501 | pt->error = -EINVAL; | |
502 | return; | |
503 | } | |
504 | ||
505 | poll = kmalloc(sizeof(*poll), GFP_ATOMIC); | |
506 | if (!poll) { | |
507 | pt->error = -ENOMEM; | |
508 | return; | |
509 | } | |
49f1c68e | 510 | |
329061d3 | 511 | /* mark as double wq entry */ |
0638cd7b | 512 | wqe_private |= IO_WQE_F_DOUBLE; |
1947ddf9 | 513 | io_init_poll_iocb(poll, first->events); |
30a33669 PB |
514 | if (!io_poll_double_prepare(req)) { |
515 | /* the request is completing, just back off */ | |
516 | kfree(poll); | |
517 | return; | |
518 | } | |
329061d3 | 519 | *poll_ptr = poll; |
49f1c68e PB |
520 | } else { |
521 | /* fine to modify, there is no poll queued to race with us */ | |
522 | req->flags |= REQ_F_SINGLE_POLL; | |
329061d3 JA |
523 | } |
524 | ||
329061d3 JA |
525 | pt->nr_entries++; |
526 | poll->head = head; | |
527 | poll->wait.private = (void *) wqe_private; | |
528 | ||
529 | if (poll->events & EPOLLEXCLUSIVE) | |
530 | add_wait_queue_exclusive(head, &poll->wait); | |
531 | else | |
532 | add_wait_queue(head, &poll->wait); | |
533 | } | |
534 | ||
535 | static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, | |
536 | struct poll_table_struct *p) | |
537 | { | |
538 | struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); | |
f2ccb5ae | 539 | struct io_poll *poll = io_kiocb_to_cmd(pt->req, struct io_poll); |
329061d3 JA |
540 | |
541 | __io_queue_proc(poll, pt, head, | |
542 | (struct io_poll **) &pt->req->async_data); | |
543 | } | |
544 | ||
49f1c68e PB |
545 | static bool io_poll_can_finish_inline(struct io_kiocb *req, |
546 | struct io_poll_table *pt) | |
547 | { | |
548 | return pt->owning || io_poll_get_ownership(req); | |
549 | } | |
550 | ||
febb985c JA |
551 | static void io_poll_add_hash(struct io_kiocb *req) |
552 | { | |
553 | if (req->flags & REQ_F_HASH_LOCKED) | |
554 | io_poll_req_insert_locked(req); | |
555 | else | |
556 | io_poll_req_insert(req); | |
557 | } | |
558 | ||
de08356f PB |
559 | /* |
560 | * Returns 0 when it's handed over for polling. The caller owns the requests if | |
561 | * it returns non-zero, but otherwise should not touch it. Negative values | |
562 | * contain an error code. When the result is >0, the polling has completed | |
563 | * inline and ipt.result_mask is set to the mask. | |
564 | */ | |
329061d3 JA |
565 | static int __io_arm_poll_handler(struct io_kiocb *req, |
566 | struct io_poll *poll, | |
49f1c68e PB |
567 | struct io_poll_table *ipt, __poll_t mask, |
568 | unsigned issue_flags) | |
329061d3 JA |
569 | { |
570 | struct io_ring_ctx *ctx = req->ctx; | |
329061d3 JA |
571 | |
572 | INIT_HLIST_NODE(&req->hash_node); | |
573 | req->work.cancel_seq = atomic_read(&ctx->cancel_seq); | |
1947ddf9 | 574 | io_init_poll_iocb(poll, mask); |
329061d3 | 575 | poll->file = req->file; |
329061d3 JA |
576 | req->apoll_events = poll->events; |
577 | ||
578 | ipt->pt._key = mask; | |
579 | ipt->req = req; | |
580 | ipt->error = 0; | |
581 | ipt->nr_entries = 0; | |
329061d3 | 582 | /* |
49f1c68e PB |
583 | * Polling is either completed here or via task_work, so if we're in the |
584 | * task context we're naturally serialised with tw by merit of running | |
585 | * the same task. When it's io-wq, take the ownership to prevent tw | |
586 | * from running. However, when we're in the task context, skip taking | |
587 | * it as an optimisation. | |
588 | * | |
589 | * Note: even though the request won't be completed/freed, without | |
590 | * ownership we still can race with io_poll_wake(). | |
591 | * io_poll_can_finish_inline() tries to deal with that. | |
329061d3 | 592 | */ |
49f1c68e | 593 | ipt->owning = issue_flags & IO_URING_F_UNLOCKED; |
49f1c68e | 594 | atomic_set(&req->poll_refs, (int)ipt->owning); |
e8375e43 PB |
595 | |
596 | /* io-wq doesn't hold uring_lock */ | |
597 | if (issue_flags & IO_URING_F_UNLOCKED) | |
598 | req->flags &= ~REQ_F_HASH_LOCKED; | |
599 | ||
329061d3 JA |
600 | mask = vfs_poll(req->file, &ipt->pt) & poll->events; |
601 | ||
de08356f PB |
602 | if (unlikely(ipt->error || !ipt->nr_entries)) { |
603 | io_poll_remove_entries(req); | |
604 | ||
49f1c68e PB |
605 | if (!io_poll_can_finish_inline(req, ipt)) { |
606 | io_poll_mark_cancelled(req); | |
607 | return 0; | |
608 | } else if (mask && (poll->events & EPOLLET)) { | |
de08356f PB |
609 | ipt->result_mask = mask; |
610 | return 1; | |
de08356f | 611 | } |
49f1c68e | 612 | return ipt->error ?: -EINVAL; |
de08356f PB |
613 | } |
614 | ||
b9ba8a44 JA |
615 | if (mask && |
616 | ((poll->events & (EPOLLET|EPOLLONESHOT)) == (EPOLLET|EPOLLONESHOT))) { | |
febb985c JA |
617 | if (!io_poll_can_finish_inline(req, ipt)) { |
618 | io_poll_add_hash(req); | |
49f1c68e | 619 | return 0; |
febb985c | 620 | } |
329061d3 | 621 | io_poll_remove_entries(req); |
063a0079 | 622 | ipt->result_mask = mask; |
329061d3 | 623 | /* no one else has access to the req, forget about the ref */ |
063a0079 | 624 | return 1; |
329061d3 | 625 | } |
b9ba8a44 | 626 | |
febb985c | 627 | io_poll_add_hash(req); |
329061d3 | 628 | |
49f1c68e PB |
629 | if (mask && (poll->events & EPOLLET) && |
630 | io_poll_can_finish_inline(req, ipt)) { | |
13a99017 | 631 | __io_poll_execute(req, mask); |
329061d3 JA |
632 | return 0; |
633 | } | |
634 | ||
49f1c68e PB |
635 | if (ipt->owning) { |
636 | /* | |
2f389343 PB |
637 | * Try to release ownership. If we see a change of state, e.g. |
638 | * poll was waken up, queue up a tw, it'll deal with it. | |
49f1c68e | 639 | */ |
2f389343 | 640 | if (atomic_cmpxchg(&req->poll_refs, 1, 0) != 1) |
49f1c68e PB |
641 | __io_poll_execute(req, 0); |
642 | } | |
329061d3 JA |
643 | return 0; |
644 | } | |
645 | ||
646 | static void io_async_queue_proc(struct file *file, struct wait_queue_head *head, | |
647 | struct poll_table_struct *p) | |
648 | { | |
649 | struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); | |
650 | struct async_poll *apoll = pt->req->apoll; | |
651 | ||
652 | __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll); | |
653 | } | |
654 | ||
c16bda37 JA |
655 | /* |
656 | * We can't reliably detect loops in repeated poll triggers and issue | |
657 | * subsequently failing. But rather than fail these immediately, allow a | |
658 | * certain amount of retries before we give up. Given that this condition | |
659 | * should _rarely_ trigger even once, we should be fine with a larger value. | |
660 | */ | |
661 | #define APOLL_MAX_RETRY 128 | |
662 | ||
5204aa8c PB |
663 | static struct async_poll *io_req_alloc_apoll(struct io_kiocb *req, |
664 | unsigned issue_flags) | |
665 | { | |
666 | struct io_ring_ctx *ctx = req->ctx; | |
9b797a37 | 667 | struct io_cache_entry *entry; |
5204aa8c PB |
668 | struct async_poll *apoll; |
669 | ||
670 | if (req->flags & REQ_F_POLLED) { | |
671 | apoll = req->apoll; | |
672 | kfree(apoll->double_poll); | |
df730ec2 XL |
673 | } else if (!(issue_flags & IO_URING_F_UNLOCKED)) { |
674 | entry = io_alloc_cache_get(&ctx->apoll_cache); | |
675 | if (entry == NULL) | |
676 | goto alloc_apoll; | |
9b797a37 | 677 | apoll = container_of(entry, struct async_poll, cache); |
c16bda37 | 678 | apoll->poll.retries = APOLL_MAX_RETRY; |
5204aa8c | 679 | } else { |
df730ec2 | 680 | alloc_apoll: |
5204aa8c PB |
681 | apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); |
682 | if (unlikely(!apoll)) | |
683 | return NULL; | |
c16bda37 | 684 | apoll->poll.retries = APOLL_MAX_RETRY; |
5204aa8c PB |
685 | } |
686 | apoll->double_poll = NULL; | |
687 | req->apoll = apoll; | |
c16bda37 JA |
688 | if (unlikely(!--apoll->poll.retries)) |
689 | return NULL; | |
5204aa8c PB |
690 | return apoll; |
691 | } | |
692 | ||
329061d3 JA |
693 | int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags) |
694 | { | |
a7dd2782 | 695 | const struct io_issue_def *def = &io_issue_defs[req->opcode]; |
329061d3 JA |
696 | struct async_poll *apoll; |
697 | struct io_poll_table ipt; | |
b9ba8a44 | 698 | __poll_t mask = POLLPRI | POLLERR | EPOLLET; |
329061d3 JA |
699 | int ret; |
700 | ||
9ca9fb24 PB |
701 | /* |
702 | * apoll requests already grab the mutex to complete in the tw handler, | |
703 | * so removal from the mutex-backed hash is free, use it by default. | |
704 | */ | |
e8375e43 | 705 | req->flags |= REQ_F_HASH_LOCKED; |
9ca9fb24 | 706 | |
329061d3 JA |
707 | if (!def->pollin && !def->pollout) |
708 | return IO_APOLL_ABORTED; | |
709 | if (!file_can_poll(req->file)) | |
710 | return IO_APOLL_ABORTED; | |
329061d3 JA |
711 | if (!(req->flags & REQ_F_APOLL_MULTISHOT)) |
712 | mask |= EPOLLONESHOT; | |
713 | ||
714 | if (def->pollin) { | |
715 | mask |= EPOLLIN | EPOLLRDNORM; | |
716 | ||
717 | /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */ | |
718 | if (req->flags & REQ_F_CLEAR_POLLIN) | |
719 | mask &= ~EPOLLIN; | |
720 | } else { | |
721 | mask |= EPOLLOUT | EPOLLWRNORM; | |
722 | } | |
723 | if (def->poll_exclusive) | |
724 | mask |= EPOLLEXCLUSIVE; | |
5204aa8c PB |
725 | |
726 | apoll = io_req_alloc_apoll(req, issue_flags); | |
727 | if (!apoll) | |
728 | return IO_APOLL_ABORTED; | |
005308f7 | 729 | req->flags &= ~(REQ_F_SINGLE_POLL | REQ_F_DOUBLE_POLL); |
329061d3 JA |
730 | req->flags |= REQ_F_POLLED; |
731 | ipt.pt._qproc = io_async_queue_proc; | |
732 | ||
733 | io_kbuf_recycle(req, issue_flags); | |
734 | ||
49f1c68e | 735 | ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask, issue_flags); |
de08356f PB |
736 | if (ret) |
737 | return ret > 0 ? IO_APOLL_READY : IO_APOLL_ABORTED; | |
48863ffd | 738 | trace_io_uring_poll_arm(req, mask, apoll->poll.events); |
329061d3 JA |
739 | return IO_APOLL_OK; |
740 | } | |
741 | ||
9ca9fb24 PB |
742 | static __cold bool io_poll_remove_all_table(struct task_struct *tsk, |
743 | struct io_hash_table *table, | |
744 | bool cancel_all) | |
329061d3 | 745 | { |
e6f89be6 | 746 | unsigned nr_buckets = 1U << table->hash_bits; |
329061d3 JA |
747 | struct hlist_node *tmp; |
748 | struct io_kiocb *req; | |
749 | bool found = false; | |
750 | int i; | |
751 | ||
e6f89be6 PB |
752 | for (i = 0; i < nr_buckets; i++) { |
753 | struct io_hash_bucket *hb = &table->hbs[i]; | |
329061d3 | 754 | |
38513c46 HX |
755 | spin_lock(&hb->lock); |
756 | hlist_for_each_entry_safe(req, tmp, &hb->list, hash_node) { | |
329061d3 JA |
757 | if (io_match_task_safe(req, tsk, cancel_all)) { |
758 | hlist_del_init(&req->hash_node); | |
759 | io_poll_cancel_req(req); | |
760 | found = true; | |
761 | } | |
762 | } | |
38513c46 | 763 | spin_unlock(&hb->lock); |
329061d3 | 764 | } |
329061d3 JA |
765 | return found; |
766 | } | |
767 | ||
9ca9fb24 PB |
768 | /* |
769 | * Returns true if we found and killed one or more poll requests | |
770 | */ | |
771 | __cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk, | |
772 | bool cancel_all) | |
773 | __must_hold(&ctx->uring_lock) | |
774 | { | |
b321823a PB |
775 | bool ret; |
776 | ||
777 | ret = io_poll_remove_all_table(tsk, &ctx->cancel_table, cancel_all); | |
778 | ret |= io_poll_remove_all_table(tsk, &ctx->cancel_table_locked, cancel_all); | |
779 | return ret; | |
9ca9fb24 PB |
780 | } |
781 | ||
329061d3 | 782 | static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only, |
1ab1edb0 | 783 | struct io_cancel_data *cd, |
e6f89be6 | 784 | struct io_hash_table *table, |
1ab1edb0 | 785 | struct io_hash_bucket **out_bucket) |
329061d3 | 786 | { |
329061d3 | 787 | struct io_kiocb *req; |
e6f89be6 PB |
788 | u32 index = hash_long(cd->data, table->hash_bits); |
789 | struct io_hash_bucket *hb = &table->hbs[index]; | |
329061d3 | 790 | |
1ab1edb0 PB |
791 | *out_bucket = NULL; |
792 | ||
38513c46 HX |
793 | spin_lock(&hb->lock); |
794 | hlist_for_each_entry(req, &hb->list, hash_node) { | |
329061d3 JA |
795 | if (cd->data != req->cqe.user_data) |
796 | continue; | |
797 | if (poll_only && req->opcode != IORING_OP_POLL_ADD) | |
798 | continue; | |
799 | if (cd->flags & IORING_ASYNC_CANCEL_ALL) { | |
800 | if (cd->seq == req->work.cancel_seq) | |
801 | continue; | |
802 | req->work.cancel_seq = cd->seq; | |
803 | } | |
1ab1edb0 | 804 | *out_bucket = hb; |
329061d3 JA |
805 | return req; |
806 | } | |
38513c46 | 807 | spin_unlock(&hb->lock); |
329061d3 JA |
808 | return NULL; |
809 | } | |
810 | ||
811 | static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx, | |
1ab1edb0 | 812 | struct io_cancel_data *cd, |
e6f89be6 | 813 | struct io_hash_table *table, |
1ab1edb0 | 814 | struct io_hash_bucket **out_bucket) |
329061d3 | 815 | { |
e6f89be6 | 816 | unsigned nr_buckets = 1U << table->hash_bits; |
329061d3 JA |
817 | struct io_kiocb *req; |
818 | int i; | |
819 | ||
1ab1edb0 PB |
820 | *out_bucket = NULL; |
821 | ||
e6f89be6 PB |
822 | for (i = 0; i < nr_buckets; i++) { |
823 | struct io_hash_bucket *hb = &table->hbs[i]; | |
329061d3 | 824 | |
38513c46 HX |
825 | spin_lock(&hb->lock); |
826 | hlist_for_each_entry(req, &hb->list, hash_node) { | |
a30badf6 JA |
827 | if (io_cancel_req_match(req, cd)) { |
828 | *out_bucket = hb; | |
829 | return req; | |
830 | } | |
329061d3 | 831 | } |
38513c46 | 832 | spin_unlock(&hb->lock); |
329061d3 JA |
833 | } |
834 | return NULL; | |
835 | } | |
836 | ||
9ca9fb24 | 837 | static int io_poll_disarm(struct io_kiocb *req) |
329061d3 | 838 | { |
9ca9fb24 PB |
839 | if (!req) |
840 | return -ENOENT; | |
329061d3 | 841 | if (!io_poll_get_ownership(req)) |
9ca9fb24 | 842 | return -EALREADY; |
329061d3 JA |
843 | io_poll_remove_entries(req); |
844 | hash_del(&req->hash_node); | |
9ca9fb24 | 845 | return 0; |
329061d3 JA |
846 | } |
847 | ||
a2cdd519 | 848 | static int __io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, |
e6f89be6 | 849 | struct io_hash_table *table) |
329061d3 | 850 | { |
1ab1edb0 | 851 | struct io_hash_bucket *bucket; |
329061d3 JA |
852 | struct io_kiocb *req; |
853 | ||
d7b8b079 JA |
854 | if (cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP | |
855 | IORING_ASYNC_CANCEL_ANY)) | |
e6f89be6 | 856 | req = io_poll_file_find(ctx, cd, table, &bucket); |
329061d3 | 857 | else |
e6f89be6 | 858 | req = io_poll_find(ctx, false, cd, table, &bucket); |
1ab1edb0 PB |
859 | |
860 | if (req) | |
861 | io_poll_cancel_req(req); | |
862 | if (bucket) | |
863 | spin_unlock(&bucket->lock); | |
864 | return req ? 0 : -ENOENT; | |
329061d3 JA |
865 | } |
866 | ||
5d7943d9 PB |
867 | int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd, |
868 | unsigned issue_flags) | |
a2cdd519 | 869 | { |
9ca9fb24 PB |
870 | int ret; |
871 | ||
872 | ret = __io_poll_cancel(ctx, cd, &ctx->cancel_table); | |
873 | if (ret != -ENOENT) | |
874 | return ret; | |
875 | ||
876 | io_ring_submit_lock(ctx, issue_flags); | |
877 | ret = __io_poll_cancel(ctx, cd, &ctx->cancel_table_locked); | |
878 | io_ring_submit_unlock(ctx, issue_flags); | |
879 | return ret; | |
a2cdd519 PB |
880 | } |
881 | ||
329061d3 JA |
882 | static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe, |
883 | unsigned int flags) | |
884 | { | |
885 | u32 events; | |
886 | ||
887 | events = READ_ONCE(sqe->poll32_events); | |
888 | #ifdef __BIG_ENDIAN | |
889 | events = swahw32(events); | |
890 | #endif | |
891 | if (!(flags & IORING_POLL_ADD_MULTI)) | |
892 | events |= EPOLLONESHOT; | |
b9ba8a44 JA |
893 | if (!(flags & IORING_POLL_ADD_LEVEL)) |
894 | events |= EPOLLET; | |
895 | return demangle_poll(events) | | |
896 | (events & (EPOLLEXCLUSIVE|EPOLLONESHOT|EPOLLET)); | |
329061d3 JA |
897 | } |
898 | ||
899 | int io_poll_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
900 | { | |
f2ccb5ae | 901 | struct io_poll_update *upd = io_kiocb_to_cmd(req, struct io_poll_update); |
329061d3 JA |
902 | u32 flags; |
903 | ||
904 | if (sqe->buf_index || sqe->splice_fd_in) | |
905 | return -EINVAL; | |
906 | flags = READ_ONCE(sqe->len); | |
907 | if (flags & ~(IORING_POLL_UPDATE_EVENTS | IORING_POLL_UPDATE_USER_DATA | | |
908 | IORING_POLL_ADD_MULTI)) | |
909 | return -EINVAL; | |
910 | /* meaningless without update */ | |
911 | if (flags == IORING_POLL_ADD_MULTI) | |
912 | return -EINVAL; | |
913 | ||
914 | upd->old_user_data = READ_ONCE(sqe->addr); | |
915 | upd->update_events = flags & IORING_POLL_UPDATE_EVENTS; | |
916 | upd->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA; | |
917 | ||
918 | upd->new_user_data = READ_ONCE(sqe->off); | |
919 | if (!upd->update_user_data && upd->new_user_data) | |
920 | return -EINVAL; | |
921 | if (upd->update_events) | |
922 | upd->events = io_poll_parse_events(sqe, flags); | |
923 | else if (sqe->poll32_events) | |
924 | return -EINVAL; | |
925 | ||
926 | return 0; | |
927 | } | |
928 | ||
929 | int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
930 | { | |
f2ccb5ae | 931 | struct io_poll *poll = io_kiocb_to_cmd(req, struct io_poll); |
329061d3 JA |
932 | u32 flags; |
933 | ||
934 | if (sqe->buf_index || sqe->off || sqe->addr) | |
935 | return -EINVAL; | |
936 | flags = READ_ONCE(sqe->len); | |
d59bd748 | 937 | if (flags & ~IORING_POLL_ADD_MULTI) |
329061d3 JA |
938 | return -EINVAL; |
939 | if ((flags & IORING_POLL_ADD_MULTI) && (req->flags & REQ_F_CQE_SKIP)) | |
940 | return -EINVAL; | |
941 | ||
329061d3 JA |
942 | poll->events = io_poll_parse_events(sqe, flags); |
943 | return 0; | |
944 | } | |
945 | ||
946 | int io_poll_add(struct io_kiocb *req, unsigned int issue_flags) | |
947 | { | |
f2ccb5ae | 948 | struct io_poll *poll = io_kiocb_to_cmd(req, struct io_poll); |
329061d3 JA |
949 | struct io_poll_table ipt; |
950 | int ret; | |
951 | ||
952 | ipt.pt._qproc = io_poll_queue_proc; | |
953 | ||
9ca9fb24 PB |
954 | /* |
955 | * If sqpoll or single issuer, there is no contention for ->uring_lock | |
956 | * and we'll end up holding it in tw handlers anyway. | |
957 | */ | |
e8375e43 | 958 | if (req->ctx->flags & (IORING_SETUP_SQPOLL|IORING_SETUP_SINGLE_ISSUER)) |
9ca9fb24 | 959 | req->flags |= REQ_F_HASH_LOCKED; |
9ca9fb24 | 960 | |
49f1c68e | 961 | ret = __io_arm_poll_handler(req, poll, &ipt, poll->events, issue_flags); |
de08356f | 962 | if (ret > 0) { |
063a0079 | 963 | io_req_set_res(req, ipt.result_mask, 0); |
329061d3 JA |
964 | return IOU_OK; |
965 | } | |
de08356f | 966 | return ret ?: IOU_ISSUE_SKIP_COMPLETE; |
329061d3 JA |
967 | } |
968 | ||
969 | int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags) | |
970 | { | |
f2ccb5ae | 971 | struct io_poll_update *poll_update = io_kiocb_to_cmd(req, struct io_poll_update); |
329061d3 | 972 | struct io_ring_ctx *ctx = req->ctx; |
ad711c5d | 973 | struct io_cancel_data cd = { .ctx = ctx, .data = poll_update->old_user_data, }; |
1ab1edb0 | 974 | struct io_hash_bucket *bucket; |
329061d3 JA |
975 | struct io_kiocb *preq; |
976 | int ret2, ret = 0; | |
ef7dfac5 | 977 | struct io_tw_state ts = { .locked = true }; |
329061d3 | 978 | |
ef7dfac5 | 979 | io_ring_submit_lock(ctx, issue_flags); |
e6f89be6 | 980 | preq = io_poll_find(ctx, true, &cd, &ctx->cancel_table, &bucket); |
9ca9fb24 | 981 | ret2 = io_poll_disarm(preq); |
1ab1edb0 PB |
982 | if (bucket) |
983 | spin_unlock(&bucket->lock); | |
9ca9fb24 PB |
984 | if (!ret2) |
985 | goto found; | |
986 | if (ret2 != -ENOENT) { | |
987 | ret = ret2; | |
38513c46 HX |
988 | goto out; |
989 | } | |
9ca9fb24 | 990 | |
9ca9fb24 PB |
991 | preq = io_poll_find(ctx, true, &cd, &ctx->cancel_table_locked, &bucket); |
992 | ret2 = io_poll_disarm(preq); | |
993 | if (bucket) | |
994 | spin_unlock(&bucket->lock); | |
9ca9fb24 PB |
995 | if (ret2) { |
996 | ret = ret2; | |
329061d3 JA |
997 | goto out; |
998 | } | |
329061d3 | 999 | |
9ca9fb24 | 1000 | found: |
bce5d70c PB |
1001 | if (WARN_ON_ONCE(preq->opcode != IORING_OP_POLL_ADD)) { |
1002 | ret = -EFAULT; | |
1003 | goto out; | |
1004 | } | |
1005 | ||
329061d3 JA |
1006 | if (poll_update->update_events || poll_update->update_user_data) { |
1007 | /* only mask one event flags, keep behavior flags */ | |
1008 | if (poll_update->update_events) { | |
f2ccb5ae | 1009 | struct io_poll *poll = io_kiocb_to_cmd(preq, struct io_poll); |
329061d3 JA |
1010 | |
1011 | poll->events &= ~0xffff; | |
1012 | poll->events |= poll_update->events & 0xffff; | |
1013 | poll->events |= IO_POLL_UNMASK; | |
1014 | } | |
1015 | if (poll_update->update_user_data) | |
1016 | preq->cqe.user_data = poll_update->new_user_data; | |
1017 | ||
ef7dfac5 | 1018 | ret2 = io_poll_add(preq, issue_flags & ~IO_URING_F_UNLOCKED); |
329061d3 JA |
1019 | /* successfully updated, don't complete poll request */ |
1020 | if (!ret2 || ret2 == -EIOCBQUEUED) | |
1021 | goto out; | |
1022 | } | |
1023 | ||
1024 | req_set_fail(preq); | |
1025 | io_req_set_res(preq, -ECANCELED, 0); | |
a282967c | 1026 | io_req_task_complete(preq, &ts); |
329061d3 | 1027 | out: |
ef7dfac5 | 1028 | io_ring_submit_unlock(ctx, issue_flags); |
329061d3 JA |
1029 | if (ret < 0) { |
1030 | req_set_fail(req); | |
1031 | return ret; | |
1032 | } | |
1033 | /* complete update request, we're done with it */ | |
1034 | io_req_set_res(req, ret, 0); | |
1035 | return IOU_OK; | |
1036 | } | |
9da7471e | 1037 | |
9b797a37 | 1038 | void io_apoll_cache_free(struct io_cache_entry *entry) |
9da7471e | 1039 | { |
9b797a37 | 1040 | kfree(container_of(entry, struct async_poll, cache)); |
9da7471e | 1041 | } |