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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 | ||
fc68fcda JA |
126 | /* |
127 | * Multishot read is prepared just like a normal read/write request, only | |
128 | * difference is that we set the MULTISHOT flag. | |
129 | */ | |
130 | int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
131 | { | |
132 | int ret; | |
133 | ||
134 | ret = io_prep_rw(req, sqe); | |
135 | if (unlikely(ret)) | |
136 | return ret; | |
137 | ||
138 | req->flags |= REQ_F_APOLL_MULTISHOT; | |
139 | return 0; | |
140 | } | |
141 | ||
f3b44f92 JA |
142 | void io_readv_writev_cleanup(struct io_kiocb *req) |
143 | { | |
144 | struct io_async_rw *io = req->async_data; | |
145 | ||
146 | kfree(io->free_iovec); | |
147 | } | |
148 | ||
149 | static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) | |
150 | { | |
151 | switch (ret) { | |
152 | case -EIOCBQUEUED: | |
153 | break; | |
154 | case -ERESTARTSYS: | |
155 | case -ERESTARTNOINTR: | |
156 | case -ERESTARTNOHAND: | |
157 | case -ERESTART_RESTARTBLOCK: | |
158 | /* | |
159 | * We can't just restart the syscall, since previously | |
160 | * submitted sqes may already be in progress. Just fail this | |
161 | * IO with EINTR. | |
162 | */ | |
163 | ret = -EINTR; | |
164 | fallthrough; | |
165 | default: | |
166 | kiocb->ki_complete(kiocb, ret); | |
167 | } | |
168 | } | |
169 | ||
170 | static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req) | |
171 | { | |
f2ccb5ae | 172 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
173 | |
174 | if (rw->kiocb.ki_pos != -1) | |
175 | return &rw->kiocb.ki_pos; | |
176 | ||
177 | if (!(req->file->f_mode & FMODE_STREAM)) { | |
178 | req->flags |= REQ_F_CUR_POS; | |
179 | rw->kiocb.ki_pos = req->file->f_pos; | |
180 | return &rw->kiocb.ki_pos; | |
181 | } | |
182 | ||
183 | rw->kiocb.ki_pos = 0; | |
184 | return NULL; | |
185 | } | |
186 | ||
187 | static void io_req_task_queue_reissue(struct io_kiocb *req) | |
188 | { | |
189 | req->io_task_work.func = io_queue_iowq; | |
190 | io_req_task_work_add(req); | |
191 | } | |
192 | ||
193 | #ifdef CONFIG_BLOCK | |
194 | static bool io_resubmit_prep(struct io_kiocb *req) | |
195 | { | |
196 | struct io_async_rw *io = req->async_data; | |
197 | ||
198 | if (!req_has_async_data(req)) | |
199 | return !io_req_prep_async(req); | |
200 | iov_iter_restore(&io->s.iter, &io->s.iter_state); | |
201 | return true; | |
202 | } | |
203 | ||
204 | static bool io_rw_should_reissue(struct io_kiocb *req) | |
205 | { | |
206 | umode_t mode = file_inode(req->file)->i_mode; | |
207 | struct io_ring_ctx *ctx = req->ctx; | |
208 | ||
209 | if (!S_ISBLK(mode) && !S_ISREG(mode)) | |
210 | return false; | |
211 | if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() && | |
212 | !(ctx->flags & IORING_SETUP_IOPOLL))) | |
213 | return false; | |
214 | /* | |
215 | * If ref is dying, we might be running poll reap from the exit work. | |
216 | * Don't attempt to reissue from that path, just let it fail with | |
217 | * -EAGAIN. | |
218 | */ | |
219 | if (percpu_ref_is_dying(&ctx->refs)) | |
220 | return false; | |
221 | /* | |
222 | * Play it safe and assume not safe to re-import and reissue if we're | |
223 | * not in the original thread group (or in task context). | |
224 | */ | |
225 | if (!same_thread_group(req->task, current) || !in_task()) | |
226 | return false; | |
227 | return true; | |
228 | } | |
229 | #else | |
230 | static bool io_resubmit_prep(struct io_kiocb *req) | |
231 | { | |
232 | return false; | |
233 | } | |
234 | static bool io_rw_should_reissue(struct io_kiocb *req) | |
235 | { | |
236 | return false; | |
237 | } | |
238 | #endif | |
239 | ||
a370167f | 240 | static void io_req_end_write(struct io_kiocb *req) |
f3b44f92 | 241 | { |
f3b44f92 | 242 | if (req->flags & REQ_F_ISREG) { |
e484fd73 | 243 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 | 244 | |
e484fd73 | 245 | kiocb_end_write(&rw->kiocb); |
f3b44f92 JA |
246 | } |
247 | } | |
248 | ||
2ec33a6c JA |
249 | /* |
250 | * Trigger the notifications after having done some IO, and finish the write | |
251 | * accounting, if any. | |
252 | */ | |
253 | static void io_req_io_end(struct io_kiocb *req) | |
254 | { | |
255 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
256 | ||
2ec33a6c | 257 | if (rw->kiocb.ki_flags & IOCB_WRITE) { |
a370167f | 258 | io_req_end_write(req); |
2ec33a6c JA |
259 | fsnotify_modify(req->file); |
260 | } else { | |
261 | fsnotify_access(req->file); | |
262 | } | |
263 | } | |
264 | ||
f3b44f92 JA |
265 | static bool __io_complete_rw_common(struct io_kiocb *req, long res) |
266 | { | |
f3b44f92 JA |
267 | if (unlikely(res != req->cqe.res)) { |
268 | if ((res == -EAGAIN || res == -EOPNOTSUPP) && | |
269 | io_rw_should_reissue(req)) { | |
2ec33a6c JA |
270 | /* |
271 | * Reissue will start accounting again, finish the | |
272 | * current cycle. | |
273 | */ | |
274 | io_req_io_end(req); | |
f3b44f92 JA |
275 | req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO; |
276 | return true; | |
277 | } | |
278 | req_set_fail(req); | |
279 | req->cqe.res = res; | |
280 | } | |
281 | return false; | |
282 | } | |
283 | ||
62bb0647 | 284 | static inline int io_fixup_rw_res(struct io_kiocb *req, long res) |
4d9cb92c PB |
285 | { |
286 | struct io_async_rw *io = req->async_data; | |
287 | ||
288 | /* add previously done IO, if any */ | |
289 | if (req_has_async_data(req) && io->bytes_done > 0) { | |
290 | if (res < 0) | |
291 | res = io->bytes_done; | |
292 | else | |
293 | res += io->bytes_done; | |
294 | } | |
295 | return res; | |
296 | } | |
297 | ||
c92fcfc2 | 298 | void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts) |
b000145e | 299 | { |
099ada2c JA |
300 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
301 | struct kiocb *kiocb = &rw->kiocb; | |
302 | ||
303 | if ((kiocb->ki_flags & IOCB_DIO_CALLER_COMP) && kiocb->dio_complete) { | |
304 | long res = kiocb->dio_complete(rw->kiocb.private); | |
305 | ||
306 | io_req_set_res(req, io_fixup_rw_res(req, res), 0); | |
307 | } | |
308 | ||
2ec33a6c | 309 | io_req_io_end(req); |
3671163b PB |
310 | |
311 | if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) { | |
a282967c | 312 | unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED; |
3671163b PB |
313 | |
314 | req->cqe.flags |= io_put_kbuf(req, issue_flags); | |
315 | } | |
a282967c | 316 | io_req_task_complete(req, ts); |
b000145e JA |
317 | } |
318 | ||
f3b44f92 JA |
319 | static void io_complete_rw(struct kiocb *kiocb, long res) |
320 | { | |
321 | struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); | |
322 | struct io_kiocb *req = cmd_to_io_kiocb(rw); | |
323 | ||
099ada2c JA |
324 | if (!kiocb->dio_complete || !(kiocb->ki_flags & IOCB_DIO_CALLER_COMP)) { |
325 | if (__io_complete_rw_common(req, res)) | |
326 | return; | |
327 | io_req_set_res(req, io_fixup_rw_res(req, res), 0); | |
328 | } | |
b000145e | 329 | req->io_task_work.func = io_req_rw_complete; |
8751d154 | 330 | __io_req_task_work_add(req, IOU_F_TWQ_LAZY_WAKE); |
f3b44f92 JA |
331 | } |
332 | ||
333 | static void io_complete_rw_iopoll(struct kiocb *kiocb, long res) | |
334 | { | |
335 | struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); | |
336 | struct io_kiocb *req = cmd_to_io_kiocb(rw); | |
337 | ||
338 | if (kiocb->ki_flags & IOCB_WRITE) | |
a370167f | 339 | io_req_end_write(req); |
f3b44f92 JA |
340 | if (unlikely(res != req->cqe.res)) { |
341 | if (res == -EAGAIN && io_rw_should_reissue(req)) { | |
342 | req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO; | |
343 | return; | |
344 | } | |
345 | req->cqe.res = res; | |
346 | } | |
347 | ||
348 | /* order with io_iopoll_complete() checking ->iopoll_completed */ | |
349 | smp_store_release(&req->iopoll_completed, 1); | |
350 | } | |
351 | ||
df9830d8 | 352 | static int kiocb_done(struct io_kiocb *req, ssize_t ret, |
f3b44f92 JA |
353 | unsigned int issue_flags) |
354 | { | |
f2ccb5ae | 355 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
4d9cb92c | 356 | unsigned final_ret = io_fixup_rw_res(req, ret); |
f3b44f92 | 357 | |
1939316b | 358 | if (ret >= 0 && req->flags & REQ_F_CUR_POS) |
f3b44f92 | 359 | req->file->f_pos = rw->kiocb.ki_pos; |
df9830d8 PB |
360 | if (ret >= 0 && (rw->kiocb.ki_complete == io_complete_rw)) { |
361 | if (!__io_complete_rw_common(req, ret)) { | |
2ec33a6c JA |
362 | /* |
363 | * Safe to call io_end from here as we're inline | |
364 | * from the submission path. | |
365 | */ | |
366 | io_req_io_end(req); | |
4d9cb92c | 367 | io_req_set_res(req, final_ret, |
df9830d8 PB |
368 | io_put_kbuf(req, issue_flags)); |
369 | return IOU_OK; | |
370 | } | |
371 | } else { | |
f3b44f92 | 372 | io_rw_done(&rw->kiocb, ret); |
df9830d8 | 373 | } |
f3b44f92 JA |
374 | |
375 | if (req->flags & REQ_F_REISSUE) { | |
376 | req->flags &= ~REQ_F_REISSUE; | |
377 | if (io_resubmit_prep(req)) | |
378 | io_req_task_queue_reissue(req); | |
379 | else | |
4d9cb92c | 380 | io_req_task_queue_fail(req, final_ret); |
f3b44f92 | 381 | } |
df9830d8 | 382 | return IOU_ISSUE_SKIP_COMPLETE; |
f3b44f92 JA |
383 | } |
384 | ||
f3b44f92 JA |
385 | static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req, |
386 | struct io_rw_state *s, | |
387 | unsigned int issue_flags) | |
388 | { | |
f2ccb5ae | 389 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
390 | struct iov_iter *iter = &s->iter; |
391 | u8 opcode = req->opcode; | |
392 | struct iovec *iovec; | |
393 | void __user *buf; | |
394 | size_t sqe_len; | |
395 | ssize_t ret; | |
396 | ||
397 | if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { | |
f337a84d | 398 | ret = io_import_fixed(ddir, iter, req->imu, rw->addr, rw->len); |
f3b44f92 JA |
399 | if (ret) |
400 | return ERR_PTR(ret); | |
401 | return NULL; | |
402 | } | |
403 | ||
404 | buf = u64_to_user_ptr(rw->addr); | |
405 | sqe_len = rw->len; | |
406 | ||
d2d778fb | 407 | if (!io_issue_defs[opcode].vectored || req->flags & REQ_F_BUFFER_SELECT) { |
f3b44f92 JA |
408 | if (io_do_buffer_select(req)) { |
409 | buf = io_buffer_select(req, &sqe_len, issue_flags); | |
410 | if (!buf) | |
411 | return ERR_PTR(-ENOBUFS); | |
412 | rw->addr = (unsigned long) buf; | |
413 | rw->len = sqe_len; | |
414 | } | |
415 | ||
1e23db45 | 416 | ret = import_ubuf(ddir, buf, sqe_len, iter); |
f3b44f92 JA |
417 | if (ret) |
418 | return ERR_PTR(ret); | |
419 | return NULL; | |
420 | } | |
421 | ||
422 | iovec = s->fast_iov; | |
f3b44f92 JA |
423 | ret = __import_iovec(ddir, buf, sqe_len, UIO_FASTIOV, &iovec, iter, |
424 | req->ctx->compat); | |
425 | if (unlikely(ret < 0)) | |
426 | return ERR_PTR(ret); | |
427 | return iovec; | |
428 | } | |
429 | ||
430 | static inline int io_import_iovec(int rw, struct io_kiocb *req, | |
431 | struct iovec **iovec, struct io_rw_state *s, | |
432 | unsigned int issue_flags) | |
433 | { | |
434 | *iovec = __io_import_iovec(rw, req, s, issue_flags); | |
81594e7e | 435 | if (IS_ERR(*iovec)) |
f3b44f92 JA |
436 | return PTR_ERR(*iovec); |
437 | ||
438 | iov_iter_save_state(&s->iter, &s->iter_state); | |
439 | return 0; | |
440 | } | |
441 | ||
442 | static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) | |
443 | { | |
444 | return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos; | |
445 | } | |
446 | ||
447 | /* | |
448 | * For files that don't have ->read_iter() and ->write_iter(), handle them | |
449 | * by looping over ->read() or ->write() manually. | |
450 | */ | |
451 | static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter) | |
452 | { | |
453 | struct kiocb *kiocb = &rw->kiocb; | |
454 | struct file *file = kiocb->ki_filp; | |
455 | ssize_t ret = 0; | |
456 | loff_t *ppos; | |
457 | ||
458 | /* | |
459 | * Don't support polled IO through this interface, and we can't | |
460 | * support non-blocking either. For the latter, this just causes | |
461 | * the kiocb to be handled from an async context. | |
462 | */ | |
463 | if (kiocb->ki_flags & IOCB_HIPRI) | |
464 | return -EOPNOTSUPP; | |
465 | if ((kiocb->ki_flags & IOCB_NOWAIT) && | |
466 | !(kiocb->ki_filp->f_flags & O_NONBLOCK)) | |
467 | return -EAGAIN; | |
468 | ||
469 | ppos = io_kiocb_ppos(kiocb); | |
470 | ||
471 | while (iov_iter_count(iter)) { | |
95e49cf8 JA |
472 | void __user *addr; |
473 | size_t len; | |
f3b44f92 JA |
474 | ssize_t nr; |
475 | ||
1e23db45 | 476 | if (iter_is_ubuf(iter)) { |
95e49cf8 JA |
477 | addr = iter->ubuf + iter->iov_offset; |
478 | len = iov_iter_count(iter); | |
1e23db45 | 479 | } else if (!iov_iter_is_bvec(iter)) { |
95e49cf8 JA |
480 | addr = iter_iov_addr(iter); |
481 | len = iter_iov_len(iter); | |
f3b44f92 | 482 | } else { |
95e49cf8 JA |
483 | addr = u64_to_user_ptr(rw->addr); |
484 | len = rw->len; | |
f3b44f92 JA |
485 | } |
486 | ||
95e49cf8 JA |
487 | if (ddir == READ) |
488 | nr = file->f_op->read(file, addr, len, ppos); | |
489 | else | |
490 | nr = file->f_op->write(file, addr, len, ppos); | |
f3b44f92 JA |
491 | |
492 | if (nr < 0) { | |
493 | if (!ret) | |
494 | ret = nr; | |
495 | break; | |
496 | } | |
497 | ret += nr; | |
498 | if (!iov_iter_is_bvec(iter)) { | |
499 | iov_iter_advance(iter, nr); | |
500 | } else { | |
501 | rw->addr += nr; | |
502 | rw->len -= nr; | |
503 | if (!rw->len) | |
504 | break; | |
505 | } | |
95e49cf8 | 506 | if (nr != len) |
f3b44f92 JA |
507 | break; |
508 | } | |
509 | ||
510 | return ret; | |
511 | } | |
512 | ||
513 | static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec, | |
514 | const struct iovec *fast_iov, struct iov_iter *iter) | |
515 | { | |
516 | struct io_async_rw *io = req->async_data; | |
517 | ||
518 | memcpy(&io->s.iter, iter, sizeof(*iter)); | |
519 | io->free_iovec = iovec; | |
520 | io->bytes_done = 0; | |
521 | /* can only be fixed buffers, no need to do anything */ | |
1e23db45 | 522 | if (iov_iter_is_bvec(iter) || iter_is_ubuf(iter)) |
f3b44f92 JA |
523 | return; |
524 | if (!iovec) { | |
525 | unsigned iov_off = 0; | |
526 | ||
de4f5fed JA |
527 | io->s.iter.__iov = io->s.fast_iov; |
528 | if (iter->__iov != fast_iov) { | |
529 | iov_off = iter_iov(iter) - fast_iov; | |
530 | io->s.iter.__iov += iov_off; | |
f3b44f92 JA |
531 | } |
532 | if (io->s.fast_iov != fast_iov) | |
533 | memcpy(io->s.fast_iov + iov_off, fast_iov + iov_off, | |
534 | sizeof(struct iovec) * iter->nr_segs); | |
535 | } else { | |
536 | req->flags |= REQ_F_NEED_CLEANUP; | |
537 | } | |
538 | } | |
539 | ||
540 | static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, | |
541 | struct io_rw_state *s, bool force) | |
542 | { | |
f30bd4d0 | 543 | if (!force && !io_cold_defs[req->opcode].prep_async) |
f3b44f92 JA |
544 | return 0; |
545 | if (!req_has_async_data(req)) { | |
546 | struct io_async_rw *iorw; | |
547 | ||
548 | if (io_alloc_async_data(req)) { | |
549 | kfree(iovec); | |
550 | return -ENOMEM; | |
551 | } | |
552 | ||
553 | io_req_map_rw(req, iovec, s->fast_iov, &s->iter); | |
554 | iorw = req->async_data; | |
555 | /* we've copied and mapped the iter, ensure state is saved */ | |
556 | iov_iter_save_state(&iorw->s.iter, &iorw->s.iter_state); | |
557 | } | |
558 | return 0; | |
559 | } | |
560 | ||
561 | static inline int io_rw_prep_async(struct io_kiocb *req, int rw) | |
562 | { | |
563 | struct io_async_rw *iorw = req->async_data; | |
564 | struct iovec *iov; | |
565 | int ret; | |
566 | ||
567 | /* submission path, ->uring_lock should already be taken */ | |
568 | ret = io_import_iovec(rw, req, &iov, &iorw->s, 0); | |
569 | if (unlikely(ret < 0)) | |
570 | return ret; | |
571 | ||
572 | iorw->bytes_done = 0; | |
573 | iorw->free_iovec = iov; | |
574 | if (iov) | |
575 | req->flags |= REQ_F_NEED_CLEANUP; | |
576 | return 0; | |
577 | } | |
578 | ||
579 | int io_readv_prep_async(struct io_kiocb *req) | |
580 | { | |
de4eda9d | 581 | return io_rw_prep_async(req, ITER_DEST); |
f3b44f92 JA |
582 | } |
583 | ||
584 | int io_writev_prep_async(struct io_kiocb *req) | |
585 | { | |
de4eda9d | 586 | return io_rw_prep_async(req, ITER_SOURCE); |
f3b44f92 JA |
587 | } |
588 | ||
589 | /* | |
590 | * This is our waitqueue callback handler, registered through __folio_lock_async() | |
591 | * when we initially tried to do the IO with the iocb armed our waitqueue. | |
592 | * This gets called when the page is unlocked, and we generally expect that to | |
593 | * happen when the page IO is completed and the page is now uptodate. This will | |
594 | * queue a task_work based retry of the operation, attempting to copy the data | |
595 | * again. If the latter fails because the page was NOT uptodate, then we will | |
596 | * do a thread based blocking retry of the operation. That's the unexpected | |
597 | * slow path. | |
598 | */ | |
599 | static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, | |
600 | int sync, void *arg) | |
601 | { | |
602 | struct wait_page_queue *wpq; | |
603 | struct io_kiocb *req = wait->private; | |
f2ccb5ae | 604 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
605 | struct wait_page_key *key = arg; |
606 | ||
607 | wpq = container_of(wait, struct wait_page_queue, wait); | |
608 | ||
609 | if (!wake_page_match(wpq, key)) | |
610 | return 0; | |
611 | ||
612 | rw->kiocb.ki_flags &= ~IOCB_WAITQ; | |
613 | list_del_init(&wait->entry); | |
614 | io_req_task_queue(req); | |
615 | return 1; | |
616 | } | |
617 | ||
618 | /* | |
619 | * This controls whether a given IO request should be armed for async page | |
620 | * based retry. If we return false here, the request is handed to the async | |
621 | * worker threads for retry. If we're doing buffered reads on a regular file, | |
622 | * we prepare a private wait_page_queue entry and retry the operation. This | |
623 | * will either succeed because the page is now uptodate and unlocked, or it | |
624 | * will register a callback when the page is unlocked at IO completion. Through | |
625 | * that callback, io_uring uses task_work to setup a retry of the operation. | |
626 | * That retry will attempt the buffered read again. The retry will generally | |
627 | * succeed, or in rare cases where it fails, we then fall back to using the | |
628 | * async worker threads for a blocking retry. | |
629 | */ | |
630 | static bool io_rw_should_retry(struct io_kiocb *req) | |
631 | { | |
632 | struct io_async_rw *io = req->async_data; | |
633 | struct wait_page_queue *wait = &io->wpq; | |
f2ccb5ae | 634 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
635 | struct kiocb *kiocb = &rw->kiocb; |
636 | ||
637 | /* never retry for NOWAIT, we just complete with -EAGAIN */ | |
638 | if (req->flags & REQ_F_NOWAIT) | |
639 | return false; | |
640 | ||
641 | /* Only for buffered IO */ | |
642 | if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI)) | |
643 | return false; | |
644 | ||
645 | /* | |
646 | * just use poll if we can, and don't attempt if the fs doesn't | |
647 | * support callback based unlocks | |
648 | */ | |
649 | if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC)) | |
650 | return false; | |
651 | ||
652 | wait->wait.func = io_async_buf_func; | |
653 | wait->wait.private = req; | |
654 | wait->wait.flags = 0; | |
655 | INIT_LIST_HEAD(&wait->wait.entry); | |
656 | kiocb->ki_flags |= IOCB_WAITQ; | |
657 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
658 | kiocb->ki_waitq = wait; | |
659 | return true; | |
660 | } | |
661 | ||
662 | static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter) | |
663 | { | |
664 | struct file *file = rw->kiocb.ki_filp; | |
665 | ||
666 | if (likely(file->f_op->read_iter)) | |
667 | return call_read_iter(file, &rw->kiocb, iter); | |
668 | else if (file->f_op->read) | |
669 | return loop_rw_iter(READ, rw, iter); | |
670 | else | |
671 | return -EINVAL; | |
672 | } | |
673 | ||
4e17aaab | 674 | static bool need_complete_io(struct io_kiocb *req) |
f3b44f92 JA |
675 | { |
676 | return req->flags & REQ_F_ISREG || | |
677 | S_ISBLK(file_inode(req->file)->i_mode); | |
678 | } | |
679 | ||
f3b44f92 JA |
680 | static int io_rw_init_file(struct io_kiocb *req, fmode_t mode) |
681 | { | |
f2ccb5ae | 682 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
683 | struct kiocb *kiocb = &rw->kiocb; |
684 | struct io_ring_ctx *ctx = req->ctx; | |
685 | struct file *file = req->file; | |
686 | int ret; | |
687 | ||
688 | if (unlikely(!file || !(file->f_mode & mode))) | |
689 | return -EBADF; | |
690 | ||
3beed235 | 691 | if (!(req->flags & REQ_F_FIXED_FILE)) |
8487f083 | 692 | req->flags |= io_file_get_flags(file); |
f3b44f92 | 693 | |
5264406c | 694 | kiocb->ki_flags = file->f_iocb_flags; |
f3b44f92 JA |
695 | ret = kiocb_set_rw_flags(kiocb, rw->flags); |
696 | if (unlikely(ret)) | |
697 | return ret; | |
12e4e8c7 | 698 | kiocb->ki_flags |= IOCB_ALLOC_CACHE; |
f3b44f92 JA |
699 | |
700 | /* | |
701 | * If the file is marked O_NONBLOCK, still allow retry for it if it | |
702 | * supports async. Otherwise it's impossible to use O_NONBLOCK files | |
703 | * reliably. If not, or it IOCB_NOWAIT is set, don't retry. | |
704 | */ | |
705 | if ((kiocb->ki_flags & IOCB_NOWAIT) || | |
706 | ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req))) | |
707 | req->flags |= REQ_F_NOWAIT; | |
708 | ||
709 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
710 | if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll) | |
711 | return -EOPNOTSUPP; | |
712 | ||
713 | kiocb->private = NULL; | |
12e4e8c7 | 714 | kiocb->ki_flags |= IOCB_HIPRI; |
f3b44f92 JA |
715 | kiocb->ki_complete = io_complete_rw_iopoll; |
716 | req->iopoll_completed = 0; | |
717 | } else { | |
718 | if (kiocb->ki_flags & IOCB_HIPRI) | |
719 | return -EINVAL; | |
720 | kiocb->ki_complete = io_complete_rw; | |
721 | } | |
722 | ||
723 | return 0; | |
724 | } | |
725 | ||
a08d195b | 726 | static int __io_read(struct io_kiocb *req, unsigned int issue_flags) |
f3b44f92 | 727 | { |
f2ccb5ae | 728 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
729 | struct io_rw_state __s, *s = &__s; |
730 | struct iovec *iovec; | |
731 | struct kiocb *kiocb = &rw->kiocb; | |
732 | bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; | |
733 | struct io_async_rw *io; | |
734 | ssize_t ret, ret2; | |
735 | loff_t *ppos; | |
736 | ||
737 | if (!req_has_async_data(req)) { | |
de4eda9d | 738 | ret = io_import_iovec(ITER_DEST, req, &iovec, s, issue_flags); |
f3b44f92 JA |
739 | if (unlikely(ret < 0)) |
740 | return ret; | |
741 | } else { | |
742 | io = req->async_data; | |
743 | s = &io->s; | |
744 | ||
745 | /* | |
746 | * Safe and required to re-import if we're using provided | |
747 | * buffers, as we dropped the selected one before retry. | |
748 | */ | |
749 | if (io_do_buffer_select(req)) { | |
de4eda9d | 750 | ret = io_import_iovec(ITER_DEST, req, &iovec, s, issue_flags); |
f3b44f92 JA |
751 | if (unlikely(ret < 0)) |
752 | return ret; | |
753 | } | |
754 | ||
755 | /* | |
756 | * We come here from an earlier attempt, restore our state to | |
757 | * match in case it doesn't. It's cheap enough that we don't | |
758 | * need to make this conditional. | |
759 | */ | |
760 | iov_iter_restore(&s->iter, &s->iter_state); | |
761 | iovec = NULL; | |
762 | } | |
763 | ret = io_rw_init_file(req, FMODE_READ); | |
764 | if (unlikely(ret)) { | |
765 | kfree(iovec); | |
766 | return ret; | |
767 | } | |
768 | req->cqe.res = iov_iter_count(&s->iter); | |
769 | ||
770 | if (force_nonblock) { | |
771 | /* If the file doesn't support async, just async punt */ | |
772 | if (unlikely(!io_file_supports_nowait(req))) { | |
773 | ret = io_setup_async_rw(req, iovec, s, true); | |
774 | return ret ?: -EAGAIN; | |
775 | } | |
776 | kiocb->ki_flags |= IOCB_NOWAIT; | |
777 | } else { | |
778 | /* Ensure we clear previously set non-block flag */ | |
779 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
780 | } | |
781 | ||
782 | ppos = io_kiocb_update_pos(req); | |
783 | ||
784 | ret = rw_verify_area(READ, req->file, ppos, req->cqe.res); | |
785 | if (unlikely(ret)) { | |
786 | kfree(iovec); | |
787 | return ret; | |
788 | } | |
789 | ||
790 | ret = io_iter_do_read(rw, &s->iter); | |
791 | ||
792 | if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) { | |
793 | req->flags &= ~REQ_F_REISSUE; | |
d2d778fb JA |
794 | /* |
795 | * If we can poll, just do that. For a vectored read, we'll | |
796 | * need to copy state first. | |
797 | */ | |
798 | if (file_can_poll(req->file) && !io_issue_defs[req->opcode].vectored) | |
f3b44f92 JA |
799 | return -EAGAIN; |
800 | /* IOPOLL retry should happen for io-wq threads */ | |
801 | if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
802 | goto done; | |
803 | /* no retry on NONBLOCK nor RWF_NOWAIT */ | |
804 | if (req->flags & REQ_F_NOWAIT) | |
805 | goto done; | |
806 | ret = 0; | |
807 | } else if (ret == -EIOCBQUEUED) { | |
df9830d8 PB |
808 | if (iovec) |
809 | kfree(iovec); | |
810 | return IOU_ISSUE_SKIP_COMPLETE; | |
f3b44f92 | 811 | } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock || |
4e17aaab | 812 | (req->flags & REQ_F_NOWAIT) || !need_complete_io(req)) { |
f3b44f92 JA |
813 | /* read all, failed, already did sync or don't want to retry */ |
814 | goto done; | |
815 | } | |
816 | ||
817 | /* | |
818 | * Don't depend on the iter state matching what was consumed, or being | |
819 | * untouched in case of error. Restore it and we'll advance it | |
820 | * manually if we need to. | |
821 | */ | |
822 | iov_iter_restore(&s->iter, &s->iter_state); | |
823 | ||
824 | ret2 = io_setup_async_rw(req, iovec, s, true); | |
f3b44f92 | 825 | iovec = NULL; |
c278d9f8 PB |
826 | if (ret2) { |
827 | ret = ret > 0 ? ret : ret2; | |
828 | goto done; | |
829 | } | |
830 | ||
f3b44f92 JA |
831 | io = req->async_data; |
832 | s = &io->s; | |
833 | /* | |
834 | * Now use our persistent iterator and state, if we aren't already. | |
835 | * We've restored and mapped the iter to match. | |
836 | */ | |
837 | ||
838 | do { | |
839 | /* | |
840 | * We end up here because of a partial read, either from | |
841 | * above or inside this loop. Advance the iter by the bytes | |
842 | * that were consumed. | |
843 | */ | |
844 | iov_iter_advance(&s->iter, ret); | |
845 | if (!iov_iter_count(&s->iter)) | |
846 | break; | |
847 | io->bytes_done += ret; | |
848 | iov_iter_save_state(&s->iter, &s->iter_state); | |
849 | ||
850 | /* if we can retry, do so with the callbacks armed */ | |
851 | if (!io_rw_should_retry(req)) { | |
852 | kiocb->ki_flags &= ~IOCB_WAITQ; | |
853 | return -EAGAIN; | |
854 | } | |
855 | ||
bf68b5b3 | 856 | req->cqe.res = iov_iter_count(&s->iter); |
f3b44f92 JA |
857 | /* |
858 | * Now retry read with the IOCB_WAITQ parts set in the iocb. If | |
859 | * we get -EIOCBQUEUED, then we'll get a notification when the | |
860 | * desired page gets unlocked. We can also get a partial read | |
861 | * here, and if we do, then just retry at the new offset. | |
862 | */ | |
863 | ret = io_iter_do_read(rw, &s->iter); | |
864 | if (ret == -EIOCBQUEUED) | |
865 | return IOU_ISSUE_SKIP_COMPLETE; | |
866 | /* we got some bytes, but not all. retry. */ | |
867 | kiocb->ki_flags &= ~IOCB_WAITQ; | |
868 | iov_iter_restore(&s->iter, &s->iter_state); | |
869 | } while (ret > 0); | |
870 | done: | |
f3b44f92 JA |
871 | /* it's faster to check here then delegate to kfree */ |
872 | if (iovec) | |
873 | kfree(iovec); | |
a08d195b JA |
874 | return ret; |
875 | } | |
876 | ||
877 | int io_read(struct io_kiocb *req, unsigned int issue_flags) | |
878 | { | |
879 | int ret; | |
880 | ||
881 | ret = __io_read(req, issue_flags); | |
882 | if (ret >= 0) | |
883 | return kiocb_done(req, ret, issue_flags); | |
884 | ||
885 | return ret; | |
f3b44f92 JA |
886 | } |
887 | ||
fc68fcda JA |
888 | int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) |
889 | { | |
890 | unsigned int cflags = 0; | |
891 | int ret; | |
892 | ||
893 | /* | |
894 | * Multishot MUST be used on a pollable file | |
895 | */ | |
896 | if (!file_can_poll(req->file)) | |
897 | return -EBADFD; | |
898 | ||
899 | ret = __io_read(req, issue_flags); | |
900 | ||
901 | /* | |
902 | * If we get -EAGAIN, recycle our buffer and just let normal poll | |
903 | * handling arm it. | |
904 | */ | |
905 | if (ret == -EAGAIN) { | |
906 | io_kbuf_recycle(req, issue_flags); | |
907 | return -EAGAIN; | |
908 | } | |
909 | ||
910 | /* | |
911 | * Any successful return value will keep the multishot read armed. | |
912 | */ | |
913 | if (ret > 0) { | |
914 | /* | |
915 | * Put our buffer and post a CQE. If we fail to post a CQE, then | |
916 | * jump to the termination path. This request is then done. | |
917 | */ | |
918 | cflags = io_put_kbuf(req, issue_flags); | |
919 | ||
920 | if (io_fill_cqe_req_aux(req, | |
921 | issue_flags & IO_URING_F_COMPLETE_DEFER, | |
922 | ret, cflags | IORING_CQE_F_MORE)) { | |
923 | if (issue_flags & IO_URING_F_MULTISHOT) | |
924 | return IOU_ISSUE_SKIP_COMPLETE; | |
925 | return -EAGAIN; | |
926 | } | |
927 | } | |
928 | ||
929 | /* | |
930 | * Either an error, or we've hit overflow posting the CQE. For any | |
931 | * multishot request, hitting overflow will terminate it. | |
932 | */ | |
933 | io_req_set_res(req, ret, cflags); | |
934 | if (issue_flags & IO_URING_F_MULTISHOT) | |
935 | return IOU_STOP_MULTISHOT; | |
936 | return IOU_OK; | |
f3b44f92 JA |
937 | } |
938 | ||
939 | int io_write(struct io_kiocb *req, unsigned int issue_flags) | |
940 | { | |
f2ccb5ae | 941 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
942 | struct io_rw_state __s, *s = &__s; |
943 | struct iovec *iovec; | |
944 | struct kiocb *kiocb = &rw->kiocb; | |
945 | bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; | |
946 | ssize_t ret, ret2; | |
947 | loff_t *ppos; | |
948 | ||
949 | if (!req_has_async_data(req)) { | |
de4eda9d | 950 | ret = io_import_iovec(ITER_SOURCE, req, &iovec, s, issue_flags); |
f3b44f92 JA |
951 | if (unlikely(ret < 0)) |
952 | return ret; | |
953 | } else { | |
954 | struct io_async_rw *io = req->async_data; | |
955 | ||
956 | s = &io->s; | |
957 | iov_iter_restore(&s->iter, &s->iter_state); | |
958 | iovec = NULL; | |
959 | } | |
960 | ret = io_rw_init_file(req, FMODE_WRITE); | |
961 | if (unlikely(ret)) { | |
962 | kfree(iovec); | |
963 | return ret; | |
964 | } | |
965 | req->cqe.res = iov_iter_count(&s->iter); | |
966 | ||
967 | if (force_nonblock) { | |
968 | /* If the file doesn't support async, just async punt */ | |
969 | if (unlikely(!io_file_supports_nowait(req))) | |
970 | goto copy_iov; | |
971 | ||
4e17aaab SR |
972 | /* File path supports NOWAIT for non-direct_IO only for block devices. */ |
973 | if (!(kiocb->ki_flags & IOCB_DIRECT) && | |
974 | !(kiocb->ki_filp->f_mode & FMODE_BUF_WASYNC) && | |
975 | (req->flags & REQ_F_ISREG)) | |
f3b44f92 JA |
976 | goto copy_iov; |
977 | ||
978 | kiocb->ki_flags |= IOCB_NOWAIT; | |
979 | } else { | |
980 | /* Ensure we clear previously set non-block flag */ | |
981 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
982 | } | |
983 | ||
984 | ppos = io_kiocb_update_pos(req); | |
985 | ||
986 | ret = rw_verify_area(WRITE, req->file, ppos, req->cqe.res); | |
df9830d8 PB |
987 | if (unlikely(ret)) { |
988 | kfree(iovec); | |
989 | return ret; | |
990 | } | |
f3b44f92 | 991 | |
e484fd73 AG |
992 | if (req->flags & REQ_F_ISREG) |
993 | kiocb_start_write(kiocb); | |
f3b44f92 JA |
994 | kiocb->ki_flags |= IOCB_WRITE; |
995 | ||
996 | if (likely(req->file->f_op->write_iter)) | |
997 | ret2 = call_write_iter(req->file, kiocb, &s->iter); | |
998 | else if (req->file->f_op->write) | |
999 | ret2 = loop_rw_iter(WRITE, rw, &s->iter); | |
1000 | else | |
1001 | ret2 = -EINVAL; | |
1002 | ||
1003 | if (req->flags & REQ_F_REISSUE) { | |
1004 | req->flags &= ~REQ_F_REISSUE; | |
1005 | ret2 = -EAGAIN; | |
1006 | } | |
1007 | ||
1008 | /* | |
1009 | * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just | |
1010 | * retry them without IOCB_NOWAIT. | |
1011 | */ | |
1012 | if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) | |
1013 | ret2 = -EAGAIN; | |
1014 | /* no retry on NONBLOCK nor RWF_NOWAIT */ | |
1015 | if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) | |
1016 | goto done; | |
1017 | if (!force_nonblock || ret2 != -EAGAIN) { | |
1018 | /* IOPOLL retry should happen for io-wq threads */ | |
1019 | if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL)) | |
1020 | goto copy_iov; | |
4e17aaab SR |
1021 | |
1022 | if (ret2 != req->cqe.res && ret2 >= 0 && need_complete_io(req)) { | |
c86416c6 | 1023 | struct io_async_rw *io; |
4e17aaab | 1024 | |
1c849b48 SR |
1025 | trace_io_uring_short_write(req->ctx, kiocb->ki_pos - ret2, |
1026 | req->cqe.res, ret2); | |
1027 | ||
4e17aaab SR |
1028 | /* This is a partial write. The file pos has already been |
1029 | * updated, setup the async struct to complete the request | |
1030 | * in the worker. Also update bytes_done to account for | |
1031 | * the bytes already written. | |
1032 | */ | |
1033 | iov_iter_save_state(&s->iter, &s->iter_state); | |
1034 | ret = io_setup_async_rw(req, iovec, s, true); | |
1035 | ||
c86416c6 SR |
1036 | io = req->async_data; |
1037 | if (io) | |
1038 | io->bytes_done += ret2; | |
4e17aaab | 1039 | |
e053aaf4 | 1040 | if (kiocb->ki_flags & IOCB_WRITE) |
a370167f | 1041 | io_req_end_write(req); |
4e17aaab SR |
1042 | return ret ? ret : -EAGAIN; |
1043 | } | |
f3b44f92 | 1044 | done: |
df9830d8 | 1045 | ret = kiocb_done(req, ret2, issue_flags); |
f3b44f92 JA |
1046 | } else { |
1047 | copy_iov: | |
1048 | iov_iter_restore(&s->iter, &s->iter_state); | |
1049 | ret = io_setup_async_rw(req, iovec, s, false); | |
e053aaf4 JA |
1050 | if (!ret) { |
1051 | if (kiocb->ki_flags & IOCB_WRITE) | |
a370167f | 1052 | io_req_end_write(req); |
e053aaf4 JA |
1053 | return -EAGAIN; |
1054 | } | |
1055 | return ret; | |
f3b44f92 | 1056 | } |
f3b44f92 JA |
1057 | /* it's reportedly faster than delegating the null check to kfree() */ |
1058 | if (iovec) | |
1059 | kfree(iovec); | |
1060 | return ret; | |
1061 | } | |
1062 | ||
47b4c686 PB |
1063 | void io_rw_fail(struct io_kiocb *req) |
1064 | { | |
1065 | int res; | |
1066 | ||
1067 | res = io_fixup_rw_res(req, req->cqe.res); | |
1068 | io_req_set_res(req, res, req->cqe.flags); | |
1069 | } | |
1070 | ||
f3b44f92 JA |
1071 | int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) |
1072 | { | |
1073 | struct io_wq_work_node *pos, *start, *prev; | |
54bdd67d | 1074 | unsigned int poll_flags = 0; |
f3b44f92 JA |
1075 | DEFINE_IO_COMP_BATCH(iob); |
1076 | int nr_events = 0; | |
1077 | ||
1078 | /* | |
1079 | * Only spin for completions if we don't have multiple devices hanging | |
1080 | * off our complete list. | |
1081 | */ | |
1082 | if (ctx->poll_multi_queue || force_nonspin) | |
1083 | poll_flags |= BLK_POLL_ONESHOT; | |
1084 | ||
1085 | wq_list_for_each(pos, start, &ctx->iopoll_list) { | |
1086 | struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); | |
a1119fb0 | 1087 | struct file *file = req->file; |
f3b44f92 JA |
1088 | int ret; |
1089 | ||
1090 | /* | |
1091 | * Move completed and retryable entries to our local lists. | |
1092 | * If we find a request that requires polling, break out | |
1093 | * and complete those lists first, if we have entries there. | |
1094 | */ | |
1095 | if (READ_ONCE(req->iopoll_completed)) | |
1096 | break; | |
1097 | ||
5756a3a7 | 1098 | if (req->opcode == IORING_OP_URING_CMD) { |
a1119fb0 | 1099 | struct io_uring_cmd *ioucmd; |
5756a3a7 | 1100 | |
a1119fb0 | 1101 | ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); |
de97fcb3 JA |
1102 | ret = file->f_op->uring_cmd_iopoll(ioucmd, &iob, |
1103 | poll_flags); | |
a1119fb0 JA |
1104 | } else { |
1105 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
1106 | ||
1107 | ret = file->f_op->iopoll(&rw->kiocb, &iob, poll_flags); | |
1108 | } | |
f3b44f92 JA |
1109 | if (unlikely(ret < 0)) |
1110 | return ret; | |
1111 | else if (ret) | |
1112 | poll_flags |= BLK_POLL_ONESHOT; | |
1113 | ||
1114 | /* iopoll may have completed current req */ | |
1115 | if (!rq_list_empty(iob.req_list) || | |
1116 | READ_ONCE(req->iopoll_completed)) | |
1117 | break; | |
1118 | } | |
1119 | ||
1120 | if (!rq_list_empty(iob.req_list)) | |
1121 | iob.complete(&iob); | |
1122 | else if (!pos) | |
1123 | return 0; | |
1124 | ||
1125 | prev = start; | |
1126 | wq_list_for_each_resume(pos, prev) { | |
1127 | struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); | |
1128 | ||
1129 | /* order with io_complete_rw_iopoll(), e.g. ->result updates */ | |
1130 | if (!smp_load_acquire(&req->iopoll_completed)) | |
1131 | break; | |
1132 | nr_events++; | |
f3b44f92 | 1133 | req->cqe.flags = io_put_kbuf(req, 0); |
f3b44f92 | 1134 | } |
f3b44f92 JA |
1135 | if (unlikely(!nr_events)) |
1136 | return 0; | |
1137 | ||
f3b44f92 JA |
1138 | pos = start ? start->next : ctx->iopoll_list.first; |
1139 | wq_list_cut(&ctx->iopoll_list, prev, start); | |
ec26c225 PB |
1140 | |
1141 | if (WARN_ON_ONCE(!wq_list_empty(&ctx->submit_state.compl_reqs))) | |
1142 | return 0; | |
1143 | ctx->submit_state.compl_reqs.first = pos; | |
1144 | __io_submit_flush_completions(ctx); | |
f3b44f92 JA |
1145 | return nr_events; |
1146 | } |