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f3b44f92 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/blk-mq.h> | |
7 | #include <linux/mm.h> | |
8 | #include <linux/slab.h> | |
9 | #include <linux/fsnotify.h> | |
10 | #include <linux/poll.h> | |
11 | #include <linux/nospec.h> | |
12 | #include <linux/compat.h> | |
13 | #include <linux/io_uring.h> | |
14 | ||
15 | #include <uapi/linux/io_uring.h> | |
16 | ||
f3b44f92 JA |
17 | #include "io_uring.h" |
18 | #include "opdef.h" | |
19 | #include "kbuf.h" | |
20 | #include "rsrc.h" | |
21 | #include "rw.h" | |
22 | ||
23 | struct io_rw { | |
24 | /* NOTE: kiocb has the file as the first member, so don't do it here */ | |
25 | struct kiocb kiocb; | |
26 | u64 addr; | |
27 | u32 len; | |
28 | rwf_t flags; | |
29 | }; | |
30 | ||
31 | static inline bool io_file_supports_nowait(struct io_kiocb *req) | |
32 | { | |
33 | return req->flags & REQ_F_SUPPORT_NOWAIT; | |
34 | } | |
35 | ||
4ab9d465 DY |
36 | #ifdef CONFIG_COMPAT |
37 | static int io_iov_compat_buffer_select_prep(struct io_rw *rw) | |
38 | { | |
39 | struct compat_iovec __user *uiov; | |
40 | compat_ssize_t clen; | |
41 | ||
42 | uiov = u64_to_user_ptr(rw->addr); | |
43 | if (!access_ok(uiov, sizeof(*uiov))) | |
44 | return -EFAULT; | |
45 | if (__get_user(clen, &uiov->iov_len)) | |
46 | return -EFAULT; | |
47 | if (clen < 0) | |
48 | return -EINVAL; | |
49 | ||
50 | rw->len = clen; | |
51 | return 0; | |
52 | } | |
53 | #endif | |
54 | ||
55 | static int io_iov_buffer_select_prep(struct io_kiocb *req) | |
56 | { | |
57 | struct iovec __user *uiov; | |
58 | struct iovec iov; | |
59 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
60 | ||
61 | if (rw->len != 1) | |
62 | return -EINVAL; | |
63 | ||
64 | #ifdef CONFIG_COMPAT | |
65 | if (req->ctx->compat) | |
66 | return io_iov_compat_buffer_select_prep(rw); | |
67 | #endif | |
68 | ||
69 | uiov = u64_to_user_ptr(rw->addr); | |
70 | if (copy_from_user(&iov, uiov, sizeof(*uiov))) | |
71 | return -EFAULT; | |
72 | rw->len = iov.iov_len; | |
73 | return 0; | |
74 | } | |
75 | ||
f3b44f92 JA |
76 | int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
77 | { | |
f2ccb5ae | 78 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
79 | unsigned ioprio; |
80 | int ret; | |
81 | ||
82 | rw->kiocb.ki_pos = READ_ONCE(sqe->off); | |
83 | /* used for fixed read/write too - just read unconditionally */ | |
84 | req->buf_index = READ_ONCE(sqe->buf_index); | |
85 | ||
86 | if (req->opcode == IORING_OP_READ_FIXED || | |
87 | req->opcode == IORING_OP_WRITE_FIXED) { | |
88 | struct io_ring_ctx *ctx = req->ctx; | |
89 | u16 index; | |
90 | ||
91 | if (unlikely(req->buf_index >= ctx->nr_user_bufs)) | |
92 | return -EFAULT; | |
93 | index = array_index_nospec(req->buf_index, ctx->nr_user_bufs); | |
94 | req->imu = ctx->user_bufs[index]; | |
95 | io_req_set_rsrc_node(req, ctx, 0); | |
96 | } | |
97 | ||
98 | ioprio = READ_ONCE(sqe->ioprio); | |
99 | if (ioprio) { | |
100 | ret = ioprio_check_cap(ioprio); | |
101 | if (ret) | |
102 | return ret; | |
103 | ||
104 | rw->kiocb.ki_ioprio = ioprio; | |
105 | } else { | |
106 | rw->kiocb.ki_ioprio = get_current_ioprio(); | |
107 | } | |
099ada2c | 108 | rw->kiocb.dio_complete = NULL; |
f3b44f92 JA |
109 | |
110 | rw->addr = READ_ONCE(sqe->addr); | |
111 | rw->len = READ_ONCE(sqe->len); | |
112 | rw->flags = READ_ONCE(sqe->rw_flags); | |
4ab9d465 DY |
113 | |
114 | /* Have to do this validation here, as this is in io_read() rw->len might | |
115 | * have chanaged due to buffer selection | |
116 | */ | |
117 | if (req->opcode == IORING_OP_READV && req->flags & REQ_F_BUFFER_SELECT) { | |
118 | ret = io_iov_buffer_select_prep(req); | |
119 | if (ret) | |
120 | return ret; | |
121 | } | |
122 | ||
f3b44f92 JA |
123 | return 0; |
124 | } | |
125 | ||
126 | void io_readv_writev_cleanup(struct io_kiocb *req) | |
127 | { | |
128 | struct io_async_rw *io = req->async_data; | |
129 | ||
130 | kfree(io->free_iovec); | |
131 | } | |
132 | ||
133 | static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) | |
134 | { | |
135 | switch (ret) { | |
136 | case -EIOCBQUEUED: | |
137 | break; | |
138 | case -ERESTARTSYS: | |
139 | case -ERESTARTNOINTR: | |
140 | case -ERESTARTNOHAND: | |
141 | case -ERESTART_RESTARTBLOCK: | |
142 | /* | |
143 | * We can't just restart the syscall, since previously | |
144 | * submitted sqes may already be in progress. Just fail this | |
145 | * IO with EINTR. | |
146 | */ | |
147 | ret = -EINTR; | |
148 | fallthrough; | |
149 | default: | |
150 | kiocb->ki_complete(kiocb, ret); | |
151 | } | |
152 | } | |
153 | ||
154 | static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req) | |
155 | { | |
f2ccb5ae | 156 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
157 | |
158 | if (rw->kiocb.ki_pos != -1) | |
159 | return &rw->kiocb.ki_pos; | |
160 | ||
161 | if (!(req->file->f_mode & FMODE_STREAM)) { | |
162 | req->flags |= REQ_F_CUR_POS; | |
163 | rw->kiocb.ki_pos = req->file->f_pos; | |
164 | return &rw->kiocb.ki_pos; | |
165 | } | |
166 | ||
167 | rw->kiocb.ki_pos = 0; | |
168 | return NULL; | |
169 | } | |
170 | ||
171 | static void io_req_task_queue_reissue(struct io_kiocb *req) | |
172 | { | |
173 | req->io_task_work.func = io_queue_iowq; | |
174 | io_req_task_work_add(req); | |
175 | } | |
176 | ||
177 | #ifdef CONFIG_BLOCK | |
178 | static bool io_resubmit_prep(struct io_kiocb *req) | |
179 | { | |
180 | struct io_async_rw *io = req->async_data; | |
181 | ||
182 | if (!req_has_async_data(req)) | |
183 | return !io_req_prep_async(req); | |
184 | iov_iter_restore(&io->s.iter, &io->s.iter_state); | |
185 | return true; | |
186 | } | |
187 | ||
188 | static bool io_rw_should_reissue(struct io_kiocb *req) | |
189 | { | |
190 | umode_t mode = file_inode(req->file)->i_mode; | |
191 | struct io_ring_ctx *ctx = req->ctx; | |
192 | ||
193 | if (!S_ISBLK(mode) && !S_ISREG(mode)) | |
194 | return false; | |
195 | if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() && | |
196 | !(ctx->flags & IORING_SETUP_IOPOLL))) | |
197 | return false; | |
198 | /* | |
199 | * If ref is dying, we might be running poll reap from the exit work. | |
200 | * Don't attempt to reissue from that path, just let it fail with | |
201 | * -EAGAIN. | |
202 | */ | |
203 | if (percpu_ref_is_dying(&ctx->refs)) | |
204 | return false; | |
205 | /* | |
206 | * Play it safe and assume not safe to re-import and reissue if we're | |
207 | * not in the original thread group (or in task context). | |
208 | */ | |
209 | if (!same_thread_group(req->task, current) || !in_task()) | |
210 | return false; | |
211 | return true; | |
212 | } | |
213 | #else | |
214 | static bool io_resubmit_prep(struct io_kiocb *req) | |
215 | { | |
216 | return false; | |
217 | } | |
218 | static bool io_rw_should_reissue(struct io_kiocb *req) | |
219 | { | |
220 | return false; | |
221 | } | |
222 | #endif | |
223 | ||
a370167f | 224 | static void io_req_end_write(struct io_kiocb *req) |
f3b44f92 | 225 | { |
f3b44f92 | 226 | if (req->flags & REQ_F_ISREG) { |
e484fd73 | 227 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 | 228 | |
e484fd73 | 229 | kiocb_end_write(&rw->kiocb); |
f3b44f92 JA |
230 | } |
231 | } | |
232 | ||
2ec33a6c JA |
233 | /* |
234 | * Trigger the notifications after having done some IO, and finish the write | |
235 | * accounting, if any. | |
236 | */ | |
237 | static void io_req_io_end(struct io_kiocb *req) | |
238 | { | |
239 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
240 | ||
2ec33a6c | 241 | if (rw->kiocb.ki_flags & IOCB_WRITE) { |
a370167f | 242 | io_req_end_write(req); |
2ec33a6c JA |
243 | fsnotify_modify(req->file); |
244 | } else { | |
245 | fsnotify_access(req->file); | |
246 | } | |
247 | } | |
248 | ||
f3b44f92 JA |
249 | static bool __io_complete_rw_common(struct io_kiocb *req, long res) |
250 | { | |
f3b44f92 JA |
251 | if (unlikely(res != req->cqe.res)) { |
252 | if ((res == -EAGAIN || res == -EOPNOTSUPP) && | |
253 | io_rw_should_reissue(req)) { | |
2ec33a6c JA |
254 | /* |
255 | * Reissue will start accounting again, finish the | |
256 | * current cycle. | |
257 | */ | |
258 | io_req_io_end(req); | |
f3b44f92 JA |
259 | req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO; |
260 | return true; | |
261 | } | |
262 | req_set_fail(req); | |
263 | req->cqe.res = res; | |
264 | } | |
265 | return false; | |
266 | } | |
267 | ||
62bb0647 | 268 | static inline int io_fixup_rw_res(struct io_kiocb *req, long res) |
4d9cb92c PB |
269 | { |
270 | struct io_async_rw *io = req->async_data; | |
271 | ||
272 | /* add previously done IO, if any */ | |
273 | if (req_has_async_data(req) && io->bytes_done > 0) { | |
274 | if (res < 0) | |
275 | res = io->bytes_done; | |
276 | else | |
277 | res += io->bytes_done; | |
278 | } | |
279 | return res; | |
280 | } | |
281 | ||
c92fcfc2 | 282 | void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts) |
b000145e | 283 | { |
099ada2c JA |
284 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
285 | struct kiocb *kiocb = &rw->kiocb; | |
286 | ||
287 | if ((kiocb->ki_flags & IOCB_DIO_CALLER_COMP) && kiocb->dio_complete) { | |
288 | long res = kiocb->dio_complete(rw->kiocb.private); | |
289 | ||
290 | io_req_set_res(req, io_fixup_rw_res(req, res), 0); | |
291 | } | |
292 | ||
2ec33a6c | 293 | io_req_io_end(req); |
3671163b PB |
294 | |
295 | if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) { | |
a282967c | 296 | unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED; |
3671163b PB |
297 | |
298 | req->cqe.flags |= io_put_kbuf(req, issue_flags); | |
299 | } | |
a282967c | 300 | io_req_task_complete(req, ts); |
b000145e JA |
301 | } |
302 | ||
f3b44f92 JA |
303 | static void io_complete_rw(struct kiocb *kiocb, long res) |
304 | { | |
305 | struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); | |
306 | struct io_kiocb *req = cmd_to_io_kiocb(rw); | |
307 | ||
099ada2c JA |
308 | if (!kiocb->dio_complete || !(kiocb->ki_flags & IOCB_DIO_CALLER_COMP)) { |
309 | if (__io_complete_rw_common(req, res)) | |
310 | return; | |
311 | io_req_set_res(req, io_fixup_rw_res(req, res), 0); | |
312 | } | |
b000145e | 313 | req->io_task_work.func = io_req_rw_complete; |
8751d154 | 314 | __io_req_task_work_add(req, IOU_F_TWQ_LAZY_WAKE); |
f3b44f92 JA |
315 | } |
316 | ||
317 | static void io_complete_rw_iopoll(struct kiocb *kiocb, long res) | |
318 | { | |
319 | struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); | |
320 | struct io_kiocb *req = cmd_to_io_kiocb(rw); | |
321 | ||
322 | if (kiocb->ki_flags & IOCB_WRITE) | |
a370167f | 323 | io_req_end_write(req); |
f3b44f92 JA |
324 | if (unlikely(res != req->cqe.res)) { |
325 | if (res == -EAGAIN && io_rw_should_reissue(req)) { | |
326 | req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO; | |
327 | return; | |
328 | } | |
329 | req->cqe.res = res; | |
330 | } | |
331 | ||
332 | /* order with io_iopoll_complete() checking ->iopoll_completed */ | |
333 | smp_store_release(&req->iopoll_completed, 1); | |
334 | } | |
335 | ||
df9830d8 | 336 | static int kiocb_done(struct io_kiocb *req, ssize_t ret, |
f3b44f92 JA |
337 | unsigned int issue_flags) |
338 | { | |
f2ccb5ae | 339 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
4d9cb92c | 340 | unsigned final_ret = io_fixup_rw_res(req, ret); |
f3b44f92 | 341 | |
1939316b | 342 | if (ret >= 0 && req->flags & REQ_F_CUR_POS) |
f3b44f92 | 343 | req->file->f_pos = rw->kiocb.ki_pos; |
df9830d8 PB |
344 | if (ret >= 0 && (rw->kiocb.ki_complete == io_complete_rw)) { |
345 | if (!__io_complete_rw_common(req, ret)) { | |
2ec33a6c JA |
346 | /* |
347 | * Safe to call io_end from here as we're inline | |
348 | * from the submission path. | |
349 | */ | |
350 | io_req_io_end(req); | |
4d9cb92c | 351 | io_req_set_res(req, final_ret, |
df9830d8 PB |
352 | io_put_kbuf(req, issue_flags)); |
353 | return IOU_OK; | |
354 | } | |
355 | } else { | |
f3b44f92 | 356 | io_rw_done(&rw->kiocb, ret); |
df9830d8 | 357 | } |
f3b44f92 JA |
358 | |
359 | if (req->flags & REQ_F_REISSUE) { | |
360 | req->flags &= ~REQ_F_REISSUE; | |
361 | if (io_resubmit_prep(req)) | |
362 | io_req_task_queue_reissue(req); | |
363 | else | |
4d9cb92c | 364 | io_req_task_queue_fail(req, final_ret); |
f3b44f92 | 365 | } |
df9830d8 | 366 | return IOU_ISSUE_SKIP_COMPLETE; |
f3b44f92 JA |
367 | } |
368 | ||
f3b44f92 JA |
369 | static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req, |
370 | struct io_rw_state *s, | |
371 | unsigned int issue_flags) | |
372 | { | |
f2ccb5ae | 373 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
374 | struct iov_iter *iter = &s->iter; |
375 | u8 opcode = req->opcode; | |
376 | struct iovec *iovec; | |
377 | void __user *buf; | |
378 | size_t sqe_len; | |
379 | ssize_t ret; | |
380 | ||
381 | if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { | |
f337a84d | 382 | ret = io_import_fixed(ddir, iter, req->imu, rw->addr, rw->len); |
f3b44f92 JA |
383 | if (ret) |
384 | return ERR_PTR(ret); | |
385 | return NULL; | |
386 | } | |
387 | ||
388 | buf = u64_to_user_ptr(rw->addr); | |
389 | sqe_len = rw->len; | |
390 | ||
4ab9d465 DY |
391 | if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE || |
392 | (req->flags & REQ_F_BUFFER_SELECT)) { | |
f3b44f92 JA |
393 | if (io_do_buffer_select(req)) { |
394 | buf = io_buffer_select(req, &sqe_len, issue_flags); | |
395 | if (!buf) | |
396 | return ERR_PTR(-ENOBUFS); | |
397 | rw->addr = (unsigned long) buf; | |
398 | rw->len = sqe_len; | |
399 | } | |
400 | ||
1e23db45 | 401 | ret = import_ubuf(ddir, buf, sqe_len, iter); |
f3b44f92 JA |
402 | if (ret) |
403 | return ERR_PTR(ret); | |
404 | return NULL; | |
405 | } | |
406 | ||
407 | iovec = s->fast_iov; | |
f3b44f92 JA |
408 | ret = __import_iovec(ddir, buf, sqe_len, UIO_FASTIOV, &iovec, iter, |
409 | req->ctx->compat); | |
410 | if (unlikely(ret < 0)) | |
411 | return ERR_PTR(ret); | |
412 | return iovec; | |
413 | } | |
414 | ||
415 | static inline int io_import_iovec(int rw, struct io_kiocb *req, | |
416 | struct iovec **iovec, struct io_rw_state *s, | |
417 | unsigned int issue_flags) | |
418 | { | |
419 | *iovec = __io_import_iovec(rw, req, s, issue_flags); | |
81594e7e | 420 | if (IS_ERR(*iovec)) |
f3b44f92 JA |
421 | return PTR_ERR(*iovec); |
422 | ||
423 | iov_iter_save_state(&s->iter, &s->iter_state); | |
424 | return 0; | |
425 | } | |
426 | ||
427 | static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) | |
428 | { | |
429 | return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos; | |
430 | } | |
431 | ||
432 | /* | |
433 | * For files that don't have ->read_iter() and ->write_iter(), handle them | |
434 | * by looping over ->read() or ->write() manually. | |
435 | */ | |
436 | static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter) | |
437 | { | |
438 | struct kiocb *kiocb = &rw->kiocb; | |
439 | struct file *file = kiocb->ki_filp; | |
440 | ssize_t ret = 0; | |
441 | loff_t *ppos; | |
442 | ||
443 | /* | |
444 | * Don't support polled IO through this interface, and we can't | |
445 | * support non-blocking either. For the latter, this just causes | |
446 | * the kiocb to be handled from an async context. | |
447 | */ | |
448 | if (kiocb->ki_flags & IOCB_HIPRI) | |
449 | return -EOPNOTSUPP; | |
450 | if ((kiocb->ki_flags & IOCB_NOWAIT) && | |
451 | !(kiocb->ki_filp->f_flags & O_NONBLOCK)) | |
452 | return -EAGAIN; | |
453 | ||
454 | ppos = io_kiocb_ppos(kiocb); | |
455 | ||
456 | while (iov_iter_count(iter)) { | |
95e49cf8 JA |
457 | void __user *addr; |
458 | size_t len; | |
f3b44f92 JA |
459 | ssize_t nr; |
460 | ||
1e23db45 | 461 | if (iter_is_ubuf(iter)) { |
95e49cf8 JA |
462 | addr = iter->ubuf + iter->iov_offset; |
463 | len = iov_iter_count(iter); | |
1e23db45 | 464 | } else if (!iov_iter_is_bvec(iter)) { |
95e49cf8 JA |
465 | addr = iter_iov_addr(iter); |
466 | len = iter_iov_len(iter); | |
f3b44f92 | 467 | } else { |
95e49cf8 JA |
468 | addr = u64_to_user_ptr(rw->addr); |
469 | len = rw->len; | |
f3b44f92 JA |
470 | } |
471 | ||
95e49cf8 JA |
472 | if (ddir == READ) |
473 | nr = file->f_op->read(file, addr, len, ppos); | |
474 | else | |
475 | nr = file->f_op->write(file, addr, len, ppos); | |
f3b44f92 JA |
476 | |
477 | if (nr < 0) { | |
478 | if (!ret) | |
479 | ret = nr; | |
480 | break; | |
481 | } | |
482 | ret += nr; | |
483 | if (!iov_iter_is_bvec(iter)) { | |
484 | iov_iter_advance(iter, nr); | |
485 | } else { | |
486 | rw->addr += nr; | |
487 | rw->len -= nr; | |
488 | if (!rw->len) | |
489 | break; | |
490 | } | |
95e49cf8 | 491 | if (nr != len) |
f3b44f92 JA |
492 | break; |
493 | } | |
494 | ||
495 | return ret; | |
496 | } | |
497 | ||
498 | static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec, | |
499 | const struct iovec *fast_iov, struct iov_iter *iter) | |
500 | { | |
501 | struct io_async_rw *io = req->async_data; | |
502 | ||
503 | memcpy(&io->s.iter, iter, sizeof(*iter)); | |
504 | io->free_iovec = iovec; | |
505 | io->bytes_done = 0; | |
506 | /* can only be fixed buffers, no need to do anything */ | |
1e23db45 | 507 | if (iov_iter_is_bvec(iter) || iter_is_ubuf(iter)) |
f3b44f92 JA |
508 | return; |
509 | if (!iovec) { | |
510 | unsigned iov_off = 0; | |
511 | ||
de4f5fed JA |
512 | io->s.iter.__iov = io->s.fast_iov; |
513 | if (iter->__iov != fast_iov) { | |
514 | iov_off = iter_iov(iter) - fast_iov; | |
515 | io->s.iter.__iov += iov_off; | |
f3b44f92 JA |
516 | } |
517 | if (io->s.fast_iov != fast_iov) | |
518 | memcpy(io->s.fast_iov + iov_off, fast_iov + iov_off, | |
519 | sizeof(struct iovec) * iter->nr_segs); | |
520 | } else { | |
521 | req->flags |= REQ_F_NEED_CLEANUP; | |
522 | } | |
523 | } | |
524 | ||
525 | static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, | |
526 | struct io_rw_state *s, bool force) | |
527 | { | |
f30bd4d0 | 528 | if (!force && !io_cold_defs[req->opcode].prep_async) |
f3b44f92 JA |
529 | return 0; |
530 | if (!req_has_async_data(req)) { | |
531 | struct io_async_rw *iorw; | |
532 | ||
533 | if (io_alloc_async_data(req)) { | |
534 | kfree(iovec); | |
535 | return -ENOMEM; | |
536 | } | |
537 | ||
538 | io_req_map_rw(req, iovec, s->fast_iov, &s->iter); | |
539 | iorw = req->async_data; | |
540 | /* we've copied and mapped the iter, ensure state is saved */ | |
541 | iov_iter_save_state(&iorw->s.iter, &iorw->s.iter_state); | |
542 | } | |
543 | return 0; | |
544 | } | |
545 | ||
546 | static inline int io_rw_prep_async(struct io_kiocb *req, int rw) | |
547 | { | |
548 | struct io_async_rw *iorw = req->async_data; | |
549 | struct iovec *iov; | |
550 | int ret; | |
551 | ||
552 | /* submission path, ->uring_lock should already be taken */ | |
553 | ret = io_import_iovec(rw, req, &iov, &iorw->s, 0); | |
554 | if (unlikely(ret < 0)) | |
555 | return ret; | |
556 | ||
557 | iorw->bytes_done = 0; | |
558 | iorw->free_iovec = iov; | |
559 | if (iov) | |
560 | req->flags |= REQ_F_NEED_CLEANUP; | |
561 | return 0; | |
562 | } | |
563 | ||
564 | int io_readv_prep_async(struct io_kiocb *req) | |
565 | { | |
de4eda9d | 566 | return io_rw_prep_async(req, ITER_DEST); |
f3b44f92 JA |
567 | } |
568 | ||
569 | int io_writev_prep_async(struct io_kiocb *req) | |
570 | { | |
de4eda9d | 571 | return io_rw_prep_async(req, ITER_SOURCE); |
f3b44f92 JA |
572 | } |
573 | ||
574 | /* | |
575 | * This is our waitqueue callback handler, registered through __folio_lock_async() | |
576 | * when we initially tried to do the IO with the iocb armed our waitqueue. | |
577 | * This gets called when the page is unlocked, and we generally expect that to | |
578 | * happen when the page IO is completed and the page is now uptodate. This will | |
579 | * queue a task_work based retry of the operation, attempting to copy the data | |
580 | * again. If the latter fails because the page was NOT uptodate, then we will | |
581 | * do a thread based blocking retry of the operation. That's the unexpected | |
582 | * slow path. | |
583 | */ | |
584 | static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, | |
585 | int sync, void *arg) | |
586 | { | |
587 | struct wait_page_queue *wpq; | |
588 | struct io_kiocb *req = wait->private; | |
f2ccb5ae | 589 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
590 | struct wait_page_key *key = arg; |
591 | ||
592 | wpq = container_of(wait, struct wait_page_queue, wait); | |
593 | ||
594 | if (!wake_page_match(wpq, key)) | |
595 | return 0; | |
596 | ||
597 | rw->kiocb.ki_flags &= ~IOCB_WAITQ; | |
598 | list_del_init(&wait->entry); | |
599 | io_req_task_queue(req); | |
600 | return 1; | |
601 | } | |
602 | ||
603 | /* | |
604 | * This controls whether a given IO request should be armed for async page | |
605 | * based retry. If we return false here, the request is handed to the async | |
606 | * worker threads for retry. If we're doing buffered reads on a regular file, | |
607 | * we prepare a private wait_page_queue entry and retry the operation. This | |
608 | * will either succeed because the page is now uptodate and unlocked, or it | |
609 | * will register a callback when the page is unlocked at IO completion. Through | |
610 | * that callback, io_uring uses task_work to setup a retry of the operation. | |
611 | * That retry will attempt the buffered read again. The retry will generally | |
612 | * succeed, or in rare cases where it fails, we then fall back to using the | |
613 | * async worker threads for a blocking retry. | |
614 | */ | |
615 | static bool io_rw_should_retry(struct io_kiocb *req) | |
616 | { | |
617 | struct io_async_rw *io = req->async_data; | |
618 | struct wait_page_queue *wait = &io->wpq; | |
f2ccb5ae | 619 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
620 | struct kiocb *kiocb = &rw->kiocb; |
621 | ||
622 | /* never retry for NOWAIT, we just complete with -EAGAIN */ | |
623 | if (req->flags & REQ_F_NOWAIT) | |
624 | return false; | |
625 | ||
626 | /* Only for buffered IO */ | |
627 | if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI)) | |
628 | return false; | |
629 | ||
630 | /* | |
631 | * just use poll if we can, and don't attempt if the fs doesn't | |
632 | * support callback based unlocks | |
633 | */ | |
634 | if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC)) | |
635 | return false; | |
636 | ||
637 | wait->wait.func = io_async_buf_func; | |
638 | wait->wait.private = req; | |
639 | wait->wait.flags = 0; | |
640 | INIT_LIST_HEAD(&wait->wait.entry); | |
641 | kiocb->ki_flags |= IOCB_WAITQ; | |
642 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
643 | kiocb->ki_waitq = wait; | |
644 | return true; | |
645 | } | |
646 | ||
647 | static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter) | |
648 | { | |
649 | struct file *file = rw->kiocb.ki_filp; | |
650 | ||
651 | if (likely(file->f_op->read_iter)) | |
652 | return call_read_iter(file, &rw->kiocb, iter); | |
653 | else if (file->f_op->read) | |
654 | return loop_rw_iter(READ, rw, iter); | |
655 | else | |
656 | return -EINVAL; | |
657 | } | |
658 | ||
4e17aaab | 659 | static bool need_complete_io(struct io_kiocb *req) |
f3b44f92 JA |
660 | { |
661 | return req->flags & REQ_F_ISREG || | |
662 | S_ISBLK(file_inode(req->file)->i_mode); | |
663 | } | |
664 | ||
f3b44f92 JA |
665 | static int io_rw_init_file(struct io_kiocb *req, fmode_t mode) |
666 | { | |
f2ccb5ae | 667 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
668 | struct kiocb *kiocb = &rw->kiocb; |
669 | struct io_ring_ctx *ctx = req->ctx; | |
670 | struct file *file = req->file; | |
671 | int ret; | |
672 | ||
673 | if (unlikely(!file || !(file->f_mode & mode))) | |
674 | return -EBADF; | |
675 | ||
3beed235 | 676 | if (!(req->flags & REQ_F_FIXED_FILE)) |
8487f083 | 677 | req->flags |= io_file_get_flags(file); |
f3b44f92 | 678 | |
5264406c | 679 | kiocb->ki_flags = file->f_iocb_flags; |
f3b44f92 JA |
680 | ret = kiocb_set_rw_flags(kiocb, rw->flags); |
681 | if (unlikely(ret)) | |
682 | return ret; | |
12e4e8c7 | 683 | kiocb->ki_flags |= IOCB_ALLOC_CACHE; |
f3b44f92 JA |
684 | |
685 | /* | |
686 | * If the file is marked O_NONBLOCK, still allow retry for it if it | |
687 | * supports async. Otherwise it's impossible to use O_NONBLOCK files | |
688 | * reliably. If not, or it IOCB_NOWAIT is set, don't retry. | |
689 | */ | |
690 | if ((kiocb->ki_flags & IOCB_NOWAIT) || | |
691 | ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req))) | |
692 | req->flags |= REQ_F_NOWAIT; | |
693 | ||
694 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
695 | if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll) | |
696 | return -EOPNOTSUPP; | |
697 | ||
698 | kiocb->private = NULL; | |
12e4e8c7 | 699 | kiocb->ki_flags |= IOCB_HIPRI; |
f3b44f92 JA |
700 | kiocb->ki_complete = io_complete_rw_iopoll; |
701 | req->iopoll_completed = 0; | |
702 | } else { | |
703 | if (kiocb->ki_flags & IOCB_HIPRI) | |
704 | return -EINVAL; | |
705 | kiocb->ki_complete = io_complete_rw; | |
706 | } | |
707 | ||
708 | return 0; | |
709 | } | |
710 | ||
711 | int io_read(struct io_kiocb *req, unsigned int issue_flags) | |
712 | { | |
f2ccb5ae | 713 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
714 | struct io_rw_state __s, *s = &__s; |
715 | struct iovec *iovec; | |
716 | struct kiocb *kiocb = &rw->kiocb; | |
717 | bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; | |
718 | struct io_async_rw *io; | |
719 | ssize_t ret, ret2; | |
720 | loff_t *ppos; | |
721 | ||
722 | if (!req_has_async_data(req)) { | |
de4eda9d | 723 | ret = io_import_iovec(ITER_DEST, req, &iovec, s, issue_flags); |
f3b44f92 JA |
724 | if (unlikely(ret < 0)) |
725 | return ret; | |
726 | } else { | |
727 | io = req->async_data; | |
728 | s = &io->s; | |
729 | ||
730 | /* | |
731 | * Safe and required to re-import if we're using provided | |
732 | * buffers, as we dropped the selected one before retry. | |
733 | */ | |
734 | if (io_do_buffer_select(req)) { | |
de4eda9d | 735 | ret = io_import_iovec(ITER_DEST, req, &iovec, s, issue_flags); |
f3b44f92 JA |
736 | if (unlikely(ret < 0)) |
737 | return ret; | |
738 | } | |
739 | ||
740 | /* | |
741 | * We come here from an earlier attempt, restore our state to | |
742 | * match in case it doesn't. It's cheap enough that we don't | |
743 | * need to make this conditional. | |
744 | */ | |
745 | iov_iter_restore(&s->iter, &s->iter_state); | |
746 | iovec = NULL; | |
747 | } | |
748 | ret = io_rw_init_file(req, FMODE_READ); | |
749 | if (unlikely(ret)) { | |
750 | kfree(iovec); | |
751 | return ret; | |
752 | } | |
753 | req->cqe.res = iov_iter_count(&s->iter); | |
754 | ||
755 | if (force_nonblock) { | |
756 | /* If the file doesn't support async, just async punt */ | |
757 | if (unlikely(!io_file_supports_nowait(req))) { | |
758 | ret = io_setup_async_rw(req, iovec, s, true); | |
759 | return ret ?: -EAGAIN; | |
760 | } | |
761 | kiocb->ki_flags |= IOCB_NOWAIT; | |
762 | } else { | |
763 | /* Ensure we clear previously set non-block flag */ | |
764 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
765 | } | |
766 | ||
767 | ppos = io_kiocb_update_pos(req); | |
768 | ||
769 | ret = rw_verify_area(READ, req->file, ppos, req->cqe.res); | |
770 | if (unlikely(ret)) { | |
771 | kfree(iovec); | |
772 | return ret; | |
773 | } | |
774 | ||
775 | ret = io_iter_do_read(rw, &s->iter); | |
776 | ||
777 | if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) { | |
778 | req->flags &= ~REQ_F_REISSUE; | |
779 | /* if we can poll, just do that */ | |
780 | if (req->opcode == IORING_OP_READ && file_can_poll(req->file)) | |
781 | return -EAGAIN; | |
782 | /* IOPOLL retry should happen for io-wq threads */ | |
783 | if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
784 | goto done; | |
785 | /* no retry on NONBLOCK nor RWF_NOWAIT */ | |
786 | if (req->flags & REQ_F_NOWAIT) | |
787 | goto done; | |
788 | ret = 0; | |
789 | } else if (ret == -EIOCBQUEUED) { | |
df9830d8 PB |
790 | if (iovec) |
791 | kfree(iovec); | |
792 | return IOU_ISSUE_SKIP_COMPLETE; | |
f3b44f92 | 793 | } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock || |
4e17aaab | 794 | (req->flags & REQ_F_NOWAIT) || !need_complete_io(req)) { |
f3b44f92 JA |
795 | /* read all, failed, already did sync or don't want to retry */ |
796 | goto done; | |
797 | } | |
798 | ||
799 | /* | |
800 | * Don't depend on the iter state matching what was consumed, or being | |
801 | * untouched in case of error. Restore it and we'll advance it | |
802 | * manually if we need to. | |
803 | */ | |
804 | iov_iter_restore(&s->iter, &s->iter_state); | |
805 | ||
806 | ret2 = io_setup_async_rw(req, iovec, s, true); | |
f3b44f92 | 807 | iovec = NULL; |
c278d9f8 PB |
808 | if (ret2) { |
809 | ret = ret > 0 ? ret : ret2; | |
810 | goto done; | |
811 | } | |
812 | ||
f3b44f92 JA |
813 | io = req->async_data; |
814 | s = &io->s; | |
815 | /* | |
816 | * Now use our persistent iterator and state, if we aren't already. | |
817 | * We've restored and mapped the iter to match. | |
818 | */ | |
819 | ||
820 | do { | |
821 | /* | |
822 | * We end up here because of a partial read, either from | |
823 | * above or inside this loop. Advance the iter by the bytes | |
824 | * that were consumed. | |
825 | */ | |
826 | iov_iter_advance(&s->iter, ret); | |
827 | if (!iov_iter_count(&s->iter)) | |
828 | break; | |
829 | io->bytes_done += ret; | |
830 | iov_iter_save_state(&s->iter, &s->iter_state); | |
831 | ||
832 | /* if we can retry, do so with the callbacks armed */ | |
833 | if (!io_rw_should_retry(req)) { | |
834 | kiocb->ki_flags &= ~IOCB_WAITQ; | |
835 | return -EAGAIN; | |
836 | } | |
837 | ||
bf68b5b3 | 838 | req->cqe.res = iov_iter_count(&s->iter); |
f3b44f92 JA |
839 | /* |
840 | * Now retry read with the IOCB_WAITQ parts set in the iocb. If | |
841 | * we get -EIOCBQUEUED, then we'll get a notification when the | |
842 | * desired page gets unlocked. We can also get a partial read | |
843 | * here, and if we do, then just retry at the new offset. | |
844 | */ | |
845 | ret = io_iter_do_read(rw, &s->iter); | |
846 | if (ret == -EIOCBQUEUED) | |
847 | return IOU_ISSUE_SKIP_COMPLETE; | |
848 | /* we got some bytes, but not all. retry. */ | |
849 | kiocb->ki_flags &= ~IOCB_WAITQ; | |
850 | iov_iter_restore(&s->iter, &s->iter_state); | |
851 | } while (ret > 0); | |
852 | done: | |
f3b44f92 JA |
853 | /* it's faster to check here then delegate to kfree */ |
854 | if (iovec) | |
855 | kfree(iovec); | |
df9830d8 | 856 | return kiocb_done(req, ret, issue_flags); |
f3b44f92 JA |
857 | } |
858 | ||
859 | int io_write(struct io_kiocb *req, unsigned int issue_flags) | |
860 | { | |
f2ccb5ae | 861 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
862 | struct io_rw_state __s, *s = &__s; |
863 | struct iovec *iovec; | |
864 | struct kiocb *kiocb = &rw->kiocb; | |
865 | bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; | |
866 | ssize_t ret, ret2; | |
867 | loff_t *ppos; | |
868 | ||
869 | if (!req_has_async_data(req)) { | |
de4eda9d | 870 | ret = io_import_iovec(ITER_SOURCE, req, &iovec, s, issue_flags); |
f3b44f92 JA |
871 | if (unlikely(ret < 0)) |
872 | return ret; | |
873 | } else { | |
874 | struct io_async_rw *io = req->async_data; | |
875 | ||
876 | s = &io->s; | |
877 | iov_iter_restore(&s->iter, &s->iter_state); | |
878 | iovec = NULL; | |
879 | } | |
880 | ret = io_rw_init_file(req, FMODE_WRITE); | |
881 | if (unlikely(ret)) { | |
882 | kfree(iovec); | |
883 | return ret; | |
884 | } | |
885 | req->cqe.res = iov_iter_count(&s->iter); | |
886 | ||
887 | if (force_nonblock) { | |
888 | /* If the file doesn't support async, just async punt */ | |
889 | if (unlikely(!io_file_supports_nowait(req))) | |
890 | goto copy_iov; | |
891 | ||
4e17aaab SR |
892 | /* File path supports NOWAIT for non-direct_IO only for block devices. */ |
893 | if (!(kiocb->ki_flags & IOCB_DIRECT) && | |
894 | !(kiocb->ki_filp->f_mode & FMODE_BUF_WASYNC) && | |
895 | (req->flags & REQ_F_ISREG)) | |
f3b44f92 JA |
896 | goto copy_iov; |
897 | ||
898 | kiocb->ki_flags |= IOCB_NOWAIT; | |
899 | } else { | |
900 | /* Ensure we clear previously set non-block flag */ | |
901 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
902 | } | |
903 | ||
904 | ppos = io_kiocb_update_pos(req); | |
905 | ||
906 | ret = rw_verify_area(WRITE, req->file, ppos, req->cqe.res); | |
df9830d8 PB |
907 | if (unlikely(ret)) { |
908 | kfree(iovec); | |
909 | return ret; | |
910 | } | |
f3b44f92 | 911 | |
e484fd73 AG |
912 | if (req->flags & REQ_F_ISREG) |
913 | kiocb_start_write(kiocb); | |
f3b44f92 JA |
914 | kiocb->ki_flags |= IOCB_WRITE; |
915 | ||
916 | if (likely(req->file->f_op->write_iter)) | |
917 | ret2 = call_write_iter(req->file, kiocb, &s->iter); | |
918 | else if (req->file->f_op->write) | |
919 | ret2 = loop_rw_iter(WRITE, rw, &s->iter); | |
920 | else | |
921 | ret2 = -EINVAL; | |
922 | ||
923 | if (req->flags & REQ_F_REISSUE) { | |
924 | req->flags &= ~REQ_F_REISSUE; | |
925 | ret2 = -EAGAIN; | |
926 | } | |
927 | ||
928 | /* | |
929 | * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just | |
930 | * retry them without IOCB_NOWAIT. | |
931 | */ | |
932 | if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) | |
933 | ret2 = -EAGAIN; | |
934 | /* no retry on NONBLOCK nor RWF_NOWAIT */ | |
935 | if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) | |
936 | goto done; | |
937 | if (!force_nonblock || ret2 != -EAGAIN) { | |
938 | /* IOPOLL retry should happen for io-wq threads */ | |
939 | if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL)) | |
940 | goto copy_iov; | |
4e17aaab SR |
941 | |
942 | if (ret2 != req->cqe.res && ret2 >= 0 && need_complete_io(req)) { | |
c86416c6 | 943 | struct io_async_rw *io; |
4e17aaab | 944 | |
1c849b48 SR |
945 | trace_io_uring_short_write(req->ctx, kiocb->ki_pos - ret2, |
946 | req->cqe.res, ret2); | |
947 | ||
4e17aaab SR |
948 | /* This is a partial write. The file pos has already been |
949 | * updated, setup the async struct to complete the request | |
950 | * in the worker. Also update bytes_done to account for | |
951 | * the bytes already written. | |
952 | */ | |
953 | iov_iter_save_state(&s->iter, &s->iter_state); | |
954 | ret = io_setup_async_rw(req, iovec, s, true); | |
955 | ||
c86416c6 SR |
956 | io = req->async_data; |
957 | if (io) | |
958 | io->bytes_done += ret2; | |
4e17aaab | 959 | |
e053aaf4 | 960 | if (kiocb->ki_flags & IOCB_WRITE) |
a370167f | 961 | io_req_end_write(req); |
4e17aaab SR |
962 | return ret ? ret : -EAGAIN; |
963 | } | |
f3b44f92 | 964 | done: |
df9830d8 | 965 | ret = kiocb_done(req, ret2, issue_flags); |
f3b44f92 JA |
966 | } else { |
967 | copy_iov: | |
968 | iov_iter_restore(&s->iter, &s->iter_state); | |
969 | ret = io_setup_async_rw(req, iovec, s, false); | |
e053aaf4 JA |
970 | if (!ret) { |
971 | if (kiocb->ki_flags & IOCB_WRITE) | |
a370167f | 972 | io_req_end_write(req); |
e053aaf4 JA |
973 | return -EAGAIN; |
974 | } | |
975 | return ret; | |
f3b44f92 | 976 | } |
f3b44f92 JA |
977 | /* it's reportedly faster than delegating the null check to kfree() */ |
978 | if (iovec) | |
979 | kfree(iovec); | |
980 | return ret; | |
981 | } | |
982 | ||
47b4c686 PB |
983 | void io_rw_fail(struct io_kiocb *req) |
984 | { | |
985 | int res; | |
986 | ||
987 | res = io_fixup_rw_res(req, req->cqe.res); | |
988 | io_req_set_res(req, res, req->cqe.flags); | |
989 | } | |
990 | ||
f3b44f92 JA |
991 | int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) |
992 | { | |
993 | struct io_wq_work_node *pos, *start, *prev; | |
54bdd67d | 994 | unsigned int poll_flags = 0; |
f3b44f92 JA |
995 | DEFINE_IO_COMP_BATCH(iob); |
996 | int nr_events = 0; | |
997 | ||
998 | /* | |
999 | * Only spin for completions if we don't have multiple devices hanging | |
1000 | * off our complete list. | |
1001 | */ | |
1002 | if (ctx->poll_multi_queue || force_nonspin) | |
1003 | poll_flags |= BLK_POLL_ONESHOT; | |
1004 | ||
1005 | wq_list_for_each(pos, start, &ctx->iopoll_list) { | |
1006 | struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); | |
a1119fb0 | 1007 | struct file *file = req->file; |
f3b44f92 JA |
1008 | int ret; |
1009 | ||
1010 | /* | |
1011 | * Move completed and retryable entries to our local lists. | |
1012 | * If we find a request that requires polling, break out | |
1013 | * and complete those lists first, if we have entries there. | |
1014 | */ | |
1015 | if (READ_ONCE(req->iopoll_completed)) | |
1016 | break; | |
1017 | ||
5756a3a7 | 1018 | if (req->opcode == IORING_OP_URING_CMD) { |
a1119fb0 | 1019 | struct io_uring_cmd *ioucmd; |
5756a3a7 | 1020 | |
a1119fb0 | 1021 | ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); |
de97fcb3 JA |
1022 | ret = file->f_op->uring_cmd_iopoll(ioucmd, &iob, |
1023 | poll_flags); | |
a1119fb0 JA |
1024 | } else { |
1025 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
1026 | ||
1027 | ret = file->f_op->iopoll(&rw->kiocb, &iob, poll_flags); | |
1028 | } | |
f3b44f92 JA |
1029 | if (unlikely(ret < 0)) |
1030 | return ret; | |
1031 | else if (ret) | |
1032 | poll_flags |= BLK_POLL_ONESHOT; | |
1033 | ||
1034 | /* iopoll may have completed current req */ | |
1035 | if (!rq_list_empty(iob.req_list) || | |
1036 | READ_ONCE(req->iopoll_completed)) | |
1037 | break; | |
1038 | } | |
1039 | ||
1040 | if (!rq_list_empty(iob.req_list)) | |
1041 | iob.complete(&iob); | |
1042 | else if (!pos) | |
1043 | return 0; | |
1044 | ||
1045 | prev = start; | |
1046 | wq_list_for_each_resume(pos, prev) { | |
1047 | struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); | |
1048 | ||
1049 | /* order with io_complete_rw_iopoll(), e.g. ->result updates */ | |
1050 | if (!smp_load_acquire(&req->iopoll_completed)) | |
1051 | break; | |
1052 | nr_events++; | |
f3b44f92 | 1053 | req->cqe.flags = io_put_kbuf(req, 0); |
f3b44f92 | 1054 | } |
f3b44f92 JA |
1055 | if (unlikely(!nr_events)) |
1056 | return 0; | |
1057 | ||
f3b44f92 JA |
1058 | pos = start ? start->next : ctx->iopoll_list.first; |
1059 | wq_list_cut(&ctx->iopoll_list, prev, start); | |
ec26c225 PB |
1060 | |
1061 | if (WARN_ON_ONCE(!wq_list_empty(&ctx->submit_state.compl_reqs))) | |
1062 | return 0; | |
1063 | ctx->submit_state.compl_reqs.first = pos; | |
1064 | __io_submit_flush_completions(ctx); | |
f3b44f92 JA |
1065 | return nr_events; |
1066 | } |