]>
Commit | Line | Data |
---|---|---|
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 | ||
f3b44f92 JA |
86 | ioprio = READ_ONCE(sqe->ioprio); |
87 | if (ioprio) { | |
88 | ret = ioprio_check_cap(ioprio); | |
89 | if (ret) | |
90 | return ret; | |
91 | ||
92 | rw->kiocb.ki_ioprio = ioprio; | |
93 | } else { | |
94 | rw->kiocb.ki_ioprio = get_current_ioprio(); | |
95 | } | |
099ada2c | 96 | rw->kiocb.dio_complete = NULL; |
f3b44f92 JA |
97 | |
98 | rw->addr = READ_ONCE(sqe->addr); | |
99 | rw->len = READ_ONCE(sqe->len); | |
100 | rw->flags = READ_ONCE(sqe->rw_flags); | |
0e984ec8 JA |
101 | return 0; |
102 | } | |
103 | ||
104 | int io_prep_rwv(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
105 | { | |
106 | int ret; | |
4ab9d465 | 107 | |
0e984ec8 JA |
108 | ret = io_prep_rw(req, sqe); |
109 | if (unlikely(ret)) | |
110 | return ret; | |
111 | ||
112 | /* | |
113 | * Have to do this validation here, as this is in io_read() rw->len | |
114 | * might have chanaged due to buffer selection | |
4ab9d465 | 115 | */ |
0e984ec8 JA |
116 | if (req->flags & REQ_F_BUFFER_SELECT) |
117 | return io_iov_buffer_select_prep(req); | |
4ab9d465 | 118 | |
f3b44f92 JA |
119 | return 0; |
120 | } | |
121 | ||
f688944c JA |
122 | int io_prep_rw_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
123 | { | |
124 | struct io_ring_ctx *ctx = req->ctx; | |
125 | u16 index; | |
126 | int ret; | |
127 | ||
128 | ret = io_prep_rw(req, sqe); | |
129 | if (unlikely(ret)) | |
130 | return ret; | |
131 | ||
132 | if (unlikely(req->buf_index >= ctx->nr_user_bufs)) | |
133 | return -EFAULT; | |
134 | index = array_index_nospec(req->buf_index, ctx->nr_user_bufs); | |
135 | req->imu = ctx->user_bufs[index]; | |
136 | io_req_set_rsrc_node(req, ctx, 0); | |
137 | return 0; | |
138 | } | |
139 | ||
fc68fcda JA |
140 | /* |
141 | * Multishot read is prepared just like a normal read/write request, only | |
142 | * difference is that we set the MULTISHOT flag. | |
143 | */ | |
144 | int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
145 | { | |
49fbe994 | 146 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
fc68fcda JA |
147 | int ret; |
148 | ||
0df96fb7 JA |
149 | /* must be used with provided buffers */ |
150 | if (!(req->flags & REQ_F_BUFFER_SELECT)) | |
151 | return -EINVAL; | |
152 | ||
fc68fcda JA |
153 | ret = io_prep_rw(req, sqe); |
154 | if (unlikely(ret)) | |
155 | return ret; | |
156 | ||
49fbe994 DY |
157 | if (rw->addr || rw->len) |
158 | return -EINVAL; | |
159 | ||
fc68fcda JA |
160 | req->flags |= REQ_F_APOLL_MULTISHOT; |
161 | return 0; | |
162 | } | |
163 | ||
f3b44f92 JA |
164 | void io_readv_writev_cleanup(struct io_kiocb *req) |
165 | { | |
166 | struct io_async_rw *io = req->async_data; | |
167 | ||
168 | kfree(io->free_iovec); | |
169 | } | |
170 | ||
171 | static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) | |
172 | { | |
173 | switch (ret) { | |
174 | case -EIOCBQUEUED: | |
175 | break; | |
176 | case -ERESTARTSYS: | |
177 | case -ERESTARTNOINTR: | |
178 | case -ERESTARTNOHAND: | |
179 | case -ERESTART_RESTARTBLOCK: | |
180 | /* | |
181 | * We can't just restart the syscall, since previously | |
182 | * submitted sqes may already be in progress. Just fail this | |
183 | * IO with EINTR. | |
184 | */ | |
185 | ret = -EINTR; | |
186 | fallthrough; | |
187 | default: | |
188 | kiocb->ki_complete(kiocb, ret); | |
189 | } | |
190 | } | |
191 | ||
192 | static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req) | |
193 | { | |
f2ccb5ae | 194 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
195 | |
196 | if (rw->kiocb.ki_pos != -1) | |
197 | return &rw->kiocb.ki_pos; | |
198 | ||
199 | if (!(req->file->f_mode & FMODE_STREAM)) { | |
200 | req->flags |= REQ_F_CUR_POS; | |
201 | rw->kiocb.ki_pos = req->file->f_pos; | |
202 | return &rw->kiocb.ki_pos; | |
203 | } | |
204 | ||
205 | rw->kiocb.ki_pos = 0; | |
206 | return NULL; | |
207 | } | |
208 | ||
209 | static void io_req_task_queue_reissue(struct io_kiocb *req) | |
210 | { | |
211 | req->io_task_work.func = io_queue_iowq; | |
212 | io_req_task_work_add(req); | |
213 | } | |
214 | ||
215 | #ifdef CONFIG_BLOCK | |
216 | static bool io_resubmit_prep(struct io_kiocb *req) | |
217 | { | |
218 | struct io_async_rw *io = req->async_data; | |
219 | ||
220 | if (!req_has_async_data(req)) | |
221 | return !io_req_prep_async(req); | |
222 | iov_iter_restore(&io->s.iter, &io->s.iter_state); | |
223 | return true; | |
224 | } | |
225 | ||
226 | static bool io_rw_should_reissue(struct io_kiocb *req) | |
227 | { | |
228 | umode_t mode = file_inode(req->file)->i_mode; | |
229 | struct io_ring_ctx *ctx = req->ctx; | |
230 | ||
231 | if (!S_ISBLK(mode) && !S_ISREG(mode)) | |
232 | return false; | |
233 | if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() && | |
234 | !(ctx->flags & IORING_SETUP_IOPOLL))) | |
235 | return false; | |
236 | /* | |
237 | * If ref is dying, we might be running poll reap from the exit work. | |
238 | * Don't attempt to reissue from that path, just let it fail with | |
239 | * -EAGAIN. | |
240 | */ | |
241 | if (percpu_ref_is_dying(&ctx->refs)) | |
242 | return false; | |
243 | /* | |
244 | * Play it safe and assume not safe to re-import and reissue if we're | |
245 | * not in the original thread group (or in task context). | |
246 | */ | |
247 | if (!same_thread_group(req->task, current) || !in_task()) | |
248 | return false; | |
249 | return true; | |
250 | } | |
251 | #else | |
252 | static bool io_resubmit_prep(struct io_kiocb *req) | |
253 | { | |
254 | return false; | |
255 | } | |
256 | static bool io_rw_should_reissue(struct io_kiocb *req) | |
257 | { | |
258 | return false; | |
259 | } | |
260 | #endif | |
261 | ||
a370167f | 262 | static void io_req_end_write(struct io_kiocb *req) |
f3b44f92 | 263 | { |
f3b44f92 | 264 | if (req->flags & REQ_F_ISREG) { |
e484fd73 | 265 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 | 266 | |
e484fd73 | 267 | kiocb_end_write(&rw->kiocb); |
f3b44f92 JA |
268 | } |
269 | } | |
270 | ||
2ec33a6c JA |
271 | /* |
272 | * Trigger the notifications after having done some IO, and finish the write | |
273 | * accounting, if any. | |
274 | */ | |
275 | static void io_req_io_end(struct io_kiocb *req) | |
276 | { | |
277 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
278 | ||
2ec33a6c | 279 | if (rw->kiocb.ki_flags & IOCB_WRITE) { |
a370167f | 280 | io_req_end_write(req); |
2ec33a6c JA |
281 | fsnotify_modify(req->file); |
282 | } else { | |
283 | fsnotify_access(req->file); | |
284 | } | |
285 | } | |
286 | ||
f3b44f92 JA |
287 | static bool __io_complete_rw_common(struct io_kiocb *req, long res) |
288 | { | |
f3b44f92 JA |
289 | if (unlikely(res != req->cqe.res)) { |
290 | if ((res == -EAGAIN || res == -EOPNOTSUPP) && | |
291 | io_rw_should_reissue(req)) { | |
2ec33a6c JA |
292 | /* |
293 | * Reissue will start accounting again, finish the | |
294 | * current cycle. | |
295 | */ | |
296 | io_req_io_end(req); | |
f3b44f92 JA |
297 | req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO; |
298 | return true; | |
299 | } | |
300 | req_set_fail(req); | |
301 | req->cqe.res = res; | |
302 | } | |
303 | return false; | |
304 | } | |
305 | ||
62bb0647 | 306 | static inline int io_fixup_rw_res(struct io_kiocb *req, long res) |
4d9cb92c PB |
307 | { |
308 | struct io_async_rw *io = req->async_data; | |
309 | ||
310 | /* add previously done IO, if any */ | |
311 | if (req_has_async_data(req) && io->bytes_done > 0) { | |
312 | if (res < 0) | |
313 | res = io->bytes_done; | |
314 | else | |
315 | res += io->bytes_done; | |
316 | } | |
317 | return res; | |
318 | } | |
319 | ||
c92fcfc2 | 320 | void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts) |
b000145e | 321 | { |
099ada2c JA |
322 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
323 | struct kiocb *kiocb = &rw->kiocb; | |
324 | ||
325 | if ((kiocb->ki_flags & IOCB_DIO_CALLER_COMP) && kiocb->dio_complete) { | |
326 | long res = kiocb->dio_complete(rw->kiocb.private); | |
327 | ||
328 | io_req_set_res(req, io_fixup_rw_res(req, res), 0); | |
329 | } | |
330 | ||
2ec33a6c | 331 | io_req_io_end(req); |
3671163b PB |
332 | |
333 | if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) { | |
a282967c | 334 | unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED; |
3671163b PB |
335 | |
336 | req->cqe.flags |= io_put_kbuf(req, issue_flags); | |
337 | } | |
a282967c | 338 | io_req_task_complete(req, ts); |
b000145e JA |
339 | } |
340 | ||
f3b44f92 JA |
341 | static void io_complete_rw(struct kiocb *kiocb, long res) |
342 | { | |
343 | struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); | |
344 | struct io_kiocb *req = cmd_to_io_kiocb(rw); | |
345 | ||
099ada2c JA |
346 | if (!kiocb->dio_complete || !(kiocb->ki_flags & IOCB_DIO_CALLER_COMP)) { |
347 | if (__io_complete_rw_common(req, res)) | |
348 | return; | |
349 | io_req_set_res(req, io_fixup_rw_res(req, res), 0); | |
350 | } | |
b000145e | 351 | req->io_task_work.func = io_req_rw_complete; |
8751d154 | 352 | __io_req_task_work_add(req, IOU_F_TWQ_LAZY_WAKE); |
f3b44f92 JA |
353 | } |
354 | ||
355 | static void io_complete_rw_iopoll(struct kiocb *kiocb, long res) | |
356 | { | |
357 | struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb); | |
358 | struct io_kiocb *req = cmd_to_io_kiocb(rw); | |
359 | ||
360 | if (kiocb->ki_flags & IOCB_WRITE) | |
a370167f | 361 | io_req_end_write(req); |
f3b44f92 JA |
362 | if (unlikely(res != req->cqe.res)) { |
363 | if (res == -EAGAIN && io_rw_should_reissue(req)) { | |
364 | req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO; | |
365 | return; | |
366 | } | |
367 | req->cqe.res = res; | |
368 | } | |
369 | ||
370 | /* order with io_iopoll_complete() checking ->iopoll_completed */ | |
371 | smp_store_release(&req->iopoll_completed, 1); | |
372 | } | |
373 | ||
df9830d8 | 374 | static int kiocb_done(struct io_kiocb *req, ssize_t ret, |
f3b44f92 JA |
375 | unsigned int issue_flags) |
376 | { | |
f2ccb5ae | 377 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
4d9cb92c | 378 | unsigned final_ret = io_fixup_rw_res(req, ret); |
f3b44f92 | 379 | |
1939316b | 380 | if (ret >= 0 && req->flags & REQ_F_CUR_POS) |
f3b44f92 | 381 | req->file->f_pos = rw->kiocb.ki_pos; |
df9830d8 PB |
382 | if (ret >= 0 && (rw->kiocb.ki_complete == io_complete_rw)) { |
383 | if (!__io_complete_rw_common(req, ret)) { | |
2ec33a6c JA |
384 | /* |
385 | * Safe to call io_end from here as we're inline | |
386 | * from the submission path. | |
387 | */ | |
388 | io_req_io_end(req); | |
4d9cb92c | 389 | io_req_set_res(req, final_ret, |
df9830d8 PB |
390 | io_put_kbuf(req, issue_flags)); |
391 | return IOU_OK; | |
392 | } | |
393 | } else { | |
f3b44f92 | 394 | io_rw_done(&rw->kiocb, ret); |
df9830d8 | 395 | } |
f3b44f92 JA |
396 | |
397 | if (req->flags & REQ_F_REISSUE) { | |
398 | req->flags &= ~REQ_F_REISSUE; | |
399 | if (io_resubmit_prep(req)) | |
400 | io_req_task_queue_reissue(req); | |
401 | else | |
4d9cb92c | 402 | io_req_task_queue_fail(req, final_ret); |
f3b44f92 | 403 | } |
df9830d8 | 404 | return IOU_ISSUE_SKIP_COMPLETE; |
f3b44f92 JA |
405 | } |
406 | ||
f3b44f92 JA |
407 | static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req, |
408 | struct io_rw_state *s, | |
409 | unsigned int issue_flags) | |
410 | { | |
f2ccb5ae | 411 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
412 | struct iov_iter *iter = &s->iter; |
413 | u8 opcode = req->opcode; | |
414 | struct iovec *iovec; | |
415 | void __user *buf; | |
416 | size_t sqe_len; | |
417 | ssize_t ret; | |
418 | ||
419 | if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { | |
f337a84d | 420 | ret = io_import_fixed(ddir, iter, req->imu, rw->addr, rw->len); |
f3b44f92 JA |
421 | if (ret) |
422 | return ERR_PTR(ret); | |
423 | return NULL; | |
424 | } | |
425 | ||
426 | buf = u64_to_user_ptr(rw->addr); | |
427 | sqe_len = rw->len; | |
428 | ||
d2d778fb | 429 | if (!io_issue_defs[opcode].vectored || req->flags & REQ_F_BUFFER_SELECT) { |
f3b44f92 JA |
430 | if (io_do_buffer_select(req)) { |
431 | buf = io_buffer_select(req, &sqe_len, issue_flags); | |
432 | if (!buf) | |
433 | return ERR_PTR(-ENOBUFS); | |
434 | rw->addr = (unsigned long) buf; | |
435 | rw->len = sqe_len; | |
436 | } | |
437 | ||
1e23db45 | 438 | ret = import_ubuf(ddir, buf, sqe_len, iter); |
f3b44f92 JA |
439 | if (ret) |
440 | return ERR_PTR(ret); | |
441 | return NULL; | |
442 | } | |
443 | ||
444 | iovec = s->fast_iov; | |
f3b44f92 JA |
445 | ret = __import_iovec(ddir, buf, sqe_len, UIO_FASTIOV, &iovec, iter, |
446 | req->ctx->compat); | |
447 | if (unlikely(ret < 0)) | |
448 | return ERR_PTR(ret); | |
449 | return iovec; | |
450 | } | |
451 | ||
452 | static inline int io_import_iovec(int rw, struct io_kiocb *req, | |
453 | struct iovec **iovec, struct io_rw_state *s, | |
454 | unsigned int issue_flags) | |
455 | { | |
456 | *iovec = __io_import_iovec(rw, req, s, issue_flags); | |
81594e7e | 457 | if (IS_ERR(*iovec)) |
f3b44f92 JA |
458 | return PTR_ERR(*iovec); |
459 | ||
460 | iov_iter_save_state(&s->iter, &s->iter_state); | |
461 | return 0; | |
462 | } | |
463 | ||
464 | static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) | |
465 | { | |
466 | return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos; | |
467 | } | |
468 | ||
469 | /* | |
470 | * For files that don't have ->read_iter() and ->write_iter(), handle them | |
471 | * by looping over ->read() or ->write() manually. | |
472 | */ | |
473 | static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter) | |
474 | { | |
475 | struct kiocb *kiocb = &rw->kiocb; | |
476 | struct file *file = kiocb->ki_filp; | |
477 | ssize_t ret = 0; | |
478 | loff_t *ppos; | |
479 | ||
480 | /* | |
481 | * Don't support polled IO through this interface, and we can't | |
482 | * support non-blocking either. For the latter, this just causes | |
483 | * the kiocb to be handled from an async context. | |
484 | */ | |
485 | if (kiocb->ki_flags & IOCB_HIPRI) | |
486 | return -EOPNOTSUPP; | |
487 | if ((kiocb->ki_flags & IOCB_NOWAIT) && | |
488 | !(kiocb->ki_filp->f_flags & O_NONBLOCK)) | |
489 | return -EAGAIN; | |
490 | ||
491 | ppos = io_kiocb_ppos(kiocb); | |
492 | ||
493 | while (iov_iter_count(iter)) { | |
95e49cf8 JA |
494 | void __user *addr; |
495 | size_t len; | |
f3b44f92 JA |
496 | ssize_t nr; |
497 | ||
1e23db45 | 498 | if (iter_is_ubuf(iter)) { |
95e49cf8 JA |
499 | addr = iter->ubuf + iter->iov_offset; |
500 | len = iov_iter_count(iter); | |
1e23db45 | 501 | } else if (!iov_iter_is_bvec(iter)) { |
95e49cf8 JA |
502 | addr = iter_iov_addr(iter); |
503 | len = iter_iov_len(iter); | |
f3b44f92 | 504 | } else { |
95e49cf8 JA |
505 | addr = u64_to_user_ptr(rw->addr); |
506 | len = rw->len; | |
f3b44f92 JA |
507 | } |
508 | ||
95e49cf8 JA |
509 | if (ddir == READ) |
510 | nr = file->f_op->read(file, addr, len, ppos); | |
511 | else | |
512 | nr = file->f_op->write(file, addr, len, ppos); | |
f3b44f92 JA |
513 | |
514 | if (nr < 0) { | |
515 | if (!ret) | |
516 | ret = nr; | |
517 | break; | |
518 | } | |
519 | ret += nr; | |
520 | if (!iov_iter_is_bvec(iter)) { | |
521 | iov_iter_advance(iter, nr); | |
522 | } else { | |
523 | rw->addr += nr; | |
524 | rw->len -= nr; | |
525 | if (!rw->len) | |
526 | break; | |
527 | } | |
95e49cf8 | 528 | if (nr != len) |
f3b44f92 JA |
529 | break; |
530 | } | |
531 | ||
532 | return ret; | |
533 | } | |
534 | ||
535 | static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec, | |
536 | const struct iovec *fast_iov, struct iov_iter *iter) | |
537 | { | |
538 | struct io_async_rw *io = req->async_data; | |
539 | ||
540 | memcpy(&io->s.iter, iter, sizeof(*iter)); | |
541 | io->free_iovec = iovec; | |
542 | io->bytes_done = 0; | |
543 | /* can only be fixed buffers, no need to do anything */ | |
1e23db45 | 544 | if (iov_iter_is_bvec(iter) || iter_is_ubuf(iter)) |
f3b44f92 JA |
545 | return; |
546 | if (!iovec) { | |
547 | unsigned iov_off = 0; | |
548 | ||
de4f5fed JA |
549 | io->s.iter.__iov = io->s.fast_iov; |
550 | if (iter->__iov != fast_iov) { | |
551 | iov_off = iter_iov(iter) - fast_iov; | |
552 | io->s.iter.__iov += iov_off; | |
f3b44f92 JA |
553 | } |
554 | if (io->s.fast_iov != fast_iov) | |
555 | memcpy(io->s.fast_iov + iov_off, fast_iov + iov_off, | |
556 | sizeof(struct iovec) * iter->nr_segs); | |
557 | } else { | |
558 | req->flags |= REQ_F_NEED_CLEANUP; | |
559 | } | |
560 | } | |
561 | ||
562 | static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, | |
563 | struct io_rw_state *s, bool force) | |
564 | { | |
f30bd4d0 | 565 | if (!force && !io_cold_defs[req->opcode].prep_async) |
f3b44f92 | 566 | return 0; |
0df96fb7 JA |
567 | /* opcode type doesn't need async data */ |
568 | if (!io_cold_defs[req->opcode].async_size) | |
569 | return 0; | |
f3b44f92 JA |
570 | if (!req_has_async_data(req)) { |
571 | struct io_async_rw *iorw; | |
572 | ||
573 | if (io_alloc_async_data(req)) { | |
574 | kfree(iovec); | |
575 | return -ENOMEM; | |
576 | } | |
577 | ||
578 | io_req_map_rw(req, iovec, s->fast_iov, &s->iter); | |
579 | iorw = req->async_data; | |
580 | /* we've copied and mapped the iter, ensure state is saved */ | |
581 | iov_iter_save_state(&iorw->s.iter, &iorw->s.iter_state); | |
582 | } | |
583 | return 0; | |
584 | } | |
585 | ||
586 | static inline int io_rw_prep_async(struct io_kiocb *req, int rw) | |
587 | { | |
588 | struct io_async_rw *iorw = req->async_data; | |
589 | struct iovec *iov; | |
590 | int ret; | |
591 | ||
592 | /* submission path, ->uring_lock should already be taken */ | |
593 | ret = io_import_iovec(rw, req, &iov, &iorw->s, 0); | |
594 | if (unlikely(ret < 0)) | |
595 | return ret; | |
596 | ||
597 | iorw->bytes_done = 0; | |
598 | iorw->free_iovec = iov; | |
599 | if (iov) | |
600 | req->flags |= REQ_F_NEED_CLEANUP; | |
601 | return 0; | |
602 | } | |
603 | ||
604 | int io_readv_prep_async(struct io_kiocb *req) | |
605 | { | |
de4eda9d | 606 | return io_rw_prep_async(req, ITER_DEST); |
f3b44f92 JA |
607 | } |
608 | ||
609 | int io_writev_prep_async(struct io_kiocb *req) | |
610 | { | |
de4eda9d | 611 | return io_rw_prep_async(req, ITER_SOURCE); |
f3b44f92 JA |
612 | } |
613 | ||
614 | /* | |
615 | * This is our waitqueue callback handler, registered through __folio_lock_async() | |
616 | * when we initially tried to do the IO with the iocb armed our waitqueue. | |
617 | * This gets called when the page is unlocked, and we generally expect that to | |
618 | * happen when the page IO is completed and the page is now uptodate. This will | |
619 | * queue a task_work based retry of the operation, attempting to copy the data | |
620 | * again. If the latter fails because the page was NOT uptodate, then we will | |
621 | * do a thread based blocking retry of the operation. That's the unexpected | |
622 | * slow path. | |
623 | */ | |
624 | static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode, | |
625 | int sync, void *arg) | |
626 | { | |
627 | struct wait_page_queue *wpq; | |
628 | struct io_kiocb *req = wait->private; | |
f2ccb5ae | 629 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
630 | struct wait_page_key *key = arg; |
631 | ||
632 | wpq = container_of(wait, struct wait_page_queue, wait); | |
633 | ||
634 | if (!wake_page_match(wpq, key)) | |
635 | return 0; | |
636 | ||
637 | rw->kiocb.ki_flags &= ~IOCB_WAITQ; | |
638 | list_del_init(&wait->entry); | |
639 | io_req_task_queue(req); | |
640 | return 1; | |
641 | } | |
642 | ||
643 | /* | |
644 | * This controls whether a given IO request should be armed for async page | |
645 | * based retry. If we return false here, the request is handed to the async | |
646 | * worker threads for retry. If we're doing buffered reads on a regular file, | |
647 | * we prepare a private wait_page_queue entry and retry the operation. This | |
648 | * will either succeed because the page is now uptodate and unlocked, or it | |
649 | * will register a callback when the page is unlocked at IO completion. Through | |
650 | * that callback, io_uring uses task_work to setup a retry of the operation. | |
651 | * That retry will attempt the buffered read again. The retry will generally | |
652 | * succeed, or in rare cases where it fails, we then fall back to using the | |
653 | * async worker threads for a blocking retry. | |
654 | */ | |
655 | static bool io_rw_should_retry(struct io_kiocb *req) | |
656 | { | |
657 | struct io_async_rw *io = req->async_data; | |
658 | struct wait_page_queue *wait = &io->wpq; | |
f2ccb5ae | 659 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
660 | struct kiocb *kiocb = &rw->kiocb; |
661 | ||
662 | /* never retry for NOWAIT, we just complete with -EAGAIN */ | |
663 | if (req->flags & REQ_F_NOWAIT) | |
664 | return false; | |
665 | ||
666 | /* Only for buffered IO */ | |
667 | if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI)) | |
668 | return false; | |
669 | ||
670 | /* | |
671 | * just use poll if we can, and don't attempt if the fs doesn't | |
672 | * support callback based unlocks | |
673 | */ | |
674 | if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC)) | |
675 | return false; | |
676 | ||
677 | wait->wait.func = io_async_buf_func; | |
678 | wait->wait.private = req; | |
679 | wait->wait.flags = 0; | |
680 | INIT_LIST_HEAD(&wait->wait.entry); | |
681 | kiocb->ki_flags |= IOCB_WAITQ; | |
682 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
683 | kiocb->ki_waitq = wait; | |
684 | return true; | |
685 | } | |
686 | ||
687 | static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter) | |
688 | { | |
689 | struct file *file = rw->kiocb.ki_filp; | |
690 | ||
691 | if (likely(file->f_op->read_iter)) | |
692 | return call_read_iter(file, &rw->kiocb, iter); | |
693 | else if (file->f_op->read) | |
694 | return loop_rw_iter(READ, rw, iter); | |
695 | else | |
696 | return -EINVAL; | |
697 | } | |
698 | ||
4e17aaab | 699 | static bool need_complete_io(struct io_kiocb *req) |
f3b44f92 JA |
700 | { |
701 | return req->flags & REQ_F_ISREG || | |
702 | S_ISBLK(file_inode(req->file)->i_mode); | |
703 | } | |
704 | ||
f3b44f92 JA |
705 | static int io_rw_init_file(struct io_kiocb *req, fmode_t mode) |
706 | { | |
f2ccb5ae | 707 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
708 | struct kiocb *kiocb = &rw->kiocb; |
709 | struct io_ring_ctx *ctx = req->ctx; | |
710 | struct file *file = req->file; | |
711 | int ret; | |
712 | ||
713 | if (unlikely(!file || !(file->f_mode & mode))) | |
714 | return -EBADF; | |
715 | ||
3beed235 | 716 | if (!(req->flags & REQ_F_FIXED_FILE)) |
8487f083 | 717 | req->flags |= io_file_get_flags(file); |
f3b44f92 | 718 | |
5264406c | 719 | kiocb->ki_flags = file->f_iocb_flags; |
f3b44f92 JA |
720 | ret = kiocb_set_rw_flags(kiocb, rw->flags); |
721 | if (unlikely(ret)) | |
722 | return ret; | |
12e4e8c7 | 723 | kiocb->ki_flags |= IOCB_ALLOC_CACHE; |
f3b44f92 JA |
724 | |
725 | /* | |
726 | * If the file is marked O_NONBLOCK, still allow retry for it if it | |
727 | * supports async. Otherwise it's impossible to use O_NONBLOCK files | |
728 | * reliably. If not, or it IOCB_NOWAIT is set, don't retry. | |
729 | */ | |
730 | if ((kiocb->ki_flags & IOCB_NOWAIT) || | |
731 | ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req))) | |
732 | req->flags |= REQ_F_NOWAIT; | |
733 | ||
734 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
735 | if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll) | |
736 | return -EOPNOTSUPP; | |
737 | ||
738 | kiocb->private = NULL; | |
12e4e8c7 | 739 | kiocb->ki_flags |= IOCB_HIPRI; |
f3b44f92 JA |
740 | kiocb->ki_complete = io_complete_rw_iopoll; |
741 | req->iopoll_completed = 0; | |
742 | } else { | |
743 | if (kiocb->ki_flags & IOCB_HIPRI) | |
744 | return -EINVAL; | |
745 | kiocb->ki_complete = io_complete_rw; | |
746 | } | |
747 | ||
748 | return 0; | |
749 | } | |
750 | ||
a08d195b | 751 | static int __io_read(struct io_kiocb *req, unsigned int issue_flags) |
f3b44f92 | 752 | { |
f2ccb5ae | 753 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
754 | struct io_rw_state __s, *s = &__s; |
755 | struct iovec *iovec; | |
756 | struct kiocb *kiocb = &rw->kiocb; | |
757 | bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; | |
758 | struct io_async_rw *io; | |
759 | ssize_t ret, ret2; | |
760 | loff_t *ppos; | |
761 | ||
762 | if (!req_has_async_data(req)) { | |
de4eda9d | 763 | ret = io_import_iovec(ITER_DEST, req, &iovec, s, issue_flags); |
f3b44f92 JA |
764 | if (unlikely(ret < 0)) |
765 | return ret; | |
766 | } else { | |
767 | io = req->async_data; | |
768 | s = &io->s; | |
769 | ||
770 | /* | |
771 | * Safe and required to re-import if we're using provided | |
772 | * buffers, as we dropped the selected one before retry. | |
773 | */ | |
774 | if (io_do_buffer_select(req)) { | |
de4eda9d | 775 | ret = io_import_iovec(ITER_DEST, req, &iovec, s, issue_flags); |
f3b44f92 JA |
776 | if (unlikely(ret < 0)) |
777 | return ret; | |
778 | } | |
779 | ||
780 | /* | |
781 | * We come here from an earlier attempt, restore our state to | |
782 | * match in case it doesn't. It's cheap enough that we don't | |
783 | * need to make this conditional. | |
784 | */ | |
785 | iov_iter_restore(&s->iter, &s->iter_state); | |
786 | iovec = NULL; | |
787 | } | |
788 | ret = io_rw_init_file(req, FMODE_READ); | |
789 | if (unlikely(ret)) { | |
790 | kfree(iovec); | |
791 | return ret; | |
792 | } | |
793 | req->cqe.res = iov_iter_count(&s->iter); | |
794 | ||
795 | if (force_nonblock) { | |
796 | /* If the file doesn't support async, just async punt */ | |
797 | if (unlikely(!io_file_supports_nowait(req))) { | |
798 | ret = io_setup_async_rw(req, iovec, s, true); | |
799 | return ret ?: -EAGAIN; | |
800 | } | |
801 | kiocb->ki_flags |= IOCB_NOWAIT; | |
802 | } else { | |
803 | /* Ensure we clear previously set non-block flag */ | |
804 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
805 | } | |
806 | ||
807 | ppos = io_kiocb_update_pos(req); | |
808 | ||
809 | ret = rw_verify_area(READ, req->file, ppos, req->cqe.res); | |
810 | if (unlikely(ret)) { | |
811 | kfree(iovec); | |
812 | return ret; | |
813 | } | |
814 | ||
815 | ret = io_iter_do_read(rw, &s->iter); | |
816 | ||
817 | if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) { | |
818 | req->flags &= ~REQ_F_REISSUE; | |
d2d778fb JA |
819 | /* |
820 | * If we can poll, just do that. For a vectored read, we'll | |
821 | * need to copy state first. | |
822 | */ | |
823 | if (file_can_poll(req->file) && !io_issue_defs[req->opcode].vectored) | |
f3b44f92 JA |
824 | return -EAGAIN; |
825 | /* IOPOLL retry should happen for io-wq threads */ | |
826 | if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
827 | goto done; | |
828 | /* no retry on NONBLOCK nor RWF_NOWAIT */ | |
829 | if (req->flags & REQ_F_NOWAIT) | |
830 | goto done; | |
831 | ret = 0; | |
832 | } else if (ret == -EIOCBQUEUED) { | |
df9830d8 PB |
833 | if (iovec) |
834 | kfree(iovec); | |
835 | return IOU_ISSUE_SKIP_COMPLETE; | |
f3b44f92 | 836 | } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock || |
4e17aaab | 837 | (req->flags & REQ_F_NOWAIT) || !need_complete_io(req)) { |
f3b44f92 JA |
838 | /* read all, failed, already did sync or don't want to retry */ |
839 | goto done; | |
840 | } | |
841 | ||
842 | /* | |
843 | * Don't depend on the iter state matching what was consumed, or being | |
844 | * untouched in case of error. Restore it and we'll advance it | |
845 | * manually if we need to. | |
846 | */ | |
847 | iov_iter_restore(&s->iter, &s->iter_state); | |
848 | ||
849 | ret2 = io_setup_async_rw(req, iovec, s, true); | |
f3b44f92 | 850 | iovec = NULL; |
c278d9f8 PB |
851 | if (ret2) { |
852 | ret = ret > 0 ? ret : ret2; | |
853 | goto done; | |
854 | } | |
855 | ||
f3b44f92 JA |
856 | io = req->async_data; |
857 | s = &io->s; | |
858 | /* | |
859 | * Now use our persistent iterator and state, if we aren't already. | |
860 | * We've restored and mapped the iter to match. | |
861 | */ | |
862 | ||
863 | do { | |
864 | /* | |
865 | * We end up here because of a partial read, either from | |
866 | * above or inside this loop. Advance the iter by the bytes | |
867 | * that were consumed. | |
868 | */ | |
869 | iov_iter_advance(&s->iter, ret); | |
870 | if (!iov_iter_count(&s->iter)) | |
871 | break; | |
872 | io->bytes_done += ret; | |
873 | iov_iter_save_state(&s->iter, &s->iter_state); | |
874 | ||
875 | /* if we can retry, do so with the callbacks armed */ | |
876 | if (!io_rw_should_retry(req)) { | |
877 | kiocb->ki_flags &= ~IOCB_WAITQ; | |
878 | return -EAGAIN; | |
879 | } | |
880 | ||
bf68b5b3 | 881 | req->cqe.res = iov_iter_count(&s->iter); |
f3b44f92 JA |
882 | /* |
883 | * Now retry read with the IOCB_WAITQ parts set in the iocb. If | |
884 | * we get -EIOCBQUEUED, then we'll get a notification when the | |
885 | * desired page gets unlocked. We can also get a partial read | |
886 | * here, and if we do, then just retry at the new offset. | |
887 | */ | |
888 | ret = io_iter_do_read(rw, &s->iter); | |
889 | if (ret == -EIOCBQUEUED) | |
890 | return IOU_ISSUE_SKIP_COMPLETE; | |
891 | /* we got some bytes, but not all. retry. */ | |
892 | kiocb->ki_flags &= ~IOCB_WAITQ; | |
893 | iov_iter_restore(&s->iter, &s->iter_state); | |
894 | } while (ret > 0); | |
895 | done: | |
f3b44f92 JA |
896 | /* it's faster to check here then delegate to kfree */ |
897 | if (iovec) | |
898 | kfree(iovec); | |
a08d195b JA |
899 | return ret; |
900 | } | |
901 | ||
902 | int io_read(struct io_kiocb *req, unsigned int issue_flags) | |
903 | { | |
904 | int ret; | |
905 | ||
906 | ret = __io_read(req, issue_flags); | |
907 | if (ret >= 0) | |
908 | return kiocb_done(req, ret, issue_flags); | |
909 | ||
910 | return ret; | |
f3b44f92 JA |
911 | } |
912 | ||
fc68fcda JA |
913 | int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) |
914 | { | |
e5375929 | 915 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
fc68fcda JA |
916 | unsigned int cflags = 0; |
917 | int ret; | |
918 | ||
919 | /* | |
920 | * Multishot MUST be used on a pollable file | |
921 | */ | |
922 | if (!file_can_poll(req->file)) | |
923 | return -EBADFD; | |
924 | ||
925 | ret = __io_read(req, issue_flags); | |
926 | ||
927 | /* | |
928 | * If we get -EAGAIN, recycle our buffer and just let normal poll | |
929 | * handling arm it. | |
930 | */ | |
931 | if (ret == -EAGAIN) { | |
e5375929 DY |
932 | /* |
933 | * Reset rw->len to 0 again to avoid clamping future mshot | |
934 | * reads, in case the buffer size varies. | |
935 | */ | |
936 | if (io_kbuf_recycle(req, issue_flags)) | |
937 | rw->len = 0; | |
fc68fcda JA |
938 | return -EAGAIN; |
939 | } | |
940 | ||
941 | /* | |
942 | * Any successful return value will keep the multishot read armed. | |
943 | */ | |
944 | if (ret > 0) { | |
945 | /* | |
946 | * Put our buffer and post a CQE. If we fail to post a CQE, then | |
947 | * jump to the termination path. This request is then done. | |
948 | */ | |
949 | cflags = io_put_kbuf(req, issue_flags); | |
e5375929 | 950 | rw->len = 0; /* similarly to above, reset len to 0 */ |
fc68fcda JA |
951 | |
952 | if (io_fill_cqe_req_aux(req, | |
953 | issue_flags & IO_URING_F_COMPLETE_DEFER, | |
954 | ret, cflags | IORING_CQE_F_MORE)) { | |
955 | if (issue_flags & IO_URING_F_MULTISHOT) | |
956 | return IOU_ISSUE_SKIP_COMPLETE; | |
957 | return -EAGAIN; | |
958 | } | |
959 | } | |
960 | ||
961 | /* | |
962 | * Either an error, or we've hit overflow posting the CQE. For any | |
963 | * multishot request, hitting overflow will terminate it. | |
964 | */ | |
965 | io_req_set_res(req, ret, cflags); | |
966 | if (issue_flags & IO_URING_F_MULTISHOT) | |
967 | return IOU_STOP_MULTISHOT; | |
968 | return IOU_OK; | |
f3b44f92 JA |
969 | } |
970 | ||
971 | int io_write(struct io_kiocb *req, unsigned int issue_flags) | |
972 | { | |
f2ccb5ae | 973 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); |
f3b44f92 JA |
974 | struct io_rw_state __s, *s = &__s; |
975 | struct iovec *iovec; | |
976 | struct kiocb *kiocb = &rw->kiocb; | |
977 | bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; | |
978 | ssize_t ret, ret2; | |
979 | loff_t *ppos; | |
980 | ||
981 | if (!req_has_async_data(req)) { | |
de4eda9d | 982 | ret = io_import_iovec(ITER_SOURCE, req, &iovec, s, issue_flags); |
f3b44f92 JA |
983 | if (unlikely(ret < 0)) |
984 | return ret; | |
985 | } else { | |
986 | struct io_async_rw *io = req->async_data; | |
987 | ||
988 | s = &io->s; | |
989 | iov_iter_restore(&s->iter, &s->iter_state); | |
990 | iovec = NULL; | |
991 | } | |
992 | ret = io_rw_init_file(req, FMODE_WRITE); | |
993 | if (unlikely(ret)) { | |
994 | kfree(iovec); | |
995 | return ret; | |
996 | } | |
997 | req->cqe.res = iov_iter_count(&s->iter); | |
998 | ||
999 | if (force_nonblock) { | |
1000 | /* If the file doesn't support async, just async punt */ | |
1001 | if (unlikely(!io_file_supports_nowait(req))) | |
1002 | goto copy_iov; | |
1003 | ||
4e17aaab SR |
1004 | /* File path supports NOWAIT for non-direct_IO only for block devices. */ |
1005 | if (!(kiocb->ki_flags & IOCB_DIRECT) && | |
1006 | !(kiocb->ki_filp->f_mode & FMODE_BUF_WASYNC) && | |
1007 | (req->flags & REQ_F_ISREG)) | |
f3b44f92 JA |
1008 | goto copy_iov; |
1009 | ||
1010 | kiocb->ki_flags |= IOCB_NOWAIT; | |
1011 | } else { | |
1012 | /* Ensure we clear previously set non-block flag */ | |
1013 | kiocb->ki_flags &= ~IOCB_NOWAIT; | |
1014 | } | |
1015 | ||
1016 | ppos = io_kiocb_update_pos(req); | |
1017 | ||
1018 | ret = rw_verify_area(WRITE, req->file, ppos, req->cqe.res); | |
df9830d8 PB |
1019 | if (unlikely(ret)) { |
1020 | kfree(iovec); | |
1021 | return ret; | |
1022 | } | |
f3b44f92 | 1023 | |
e484fd73 AG |
1024 | if (req->flags & REQ_F_ISREG) |
1025 | kiocb_start_write(kiocb); | |
f3b44f92 JA |
1026 | kiocb->ki_flags |= IOCB_WRITE; |
1027 | ||
1028 | if (likely(req->file->f_op->write_iter)) | |
1029 | ret2 = call_write_iter(req->file, kiocb, &s->iter); | |
1030 | else if (req->file->f_op->write) | |
1031 | ret2 = loop_rw_iter(WRITE, rw, &s->iter); | |
1032 | else | |
1033 | ret2 = -EINVAL; | |
1034 | ||
1035 | if (req->flags & REQ_F_REISSUE) { | |
1036 | req->flags &= ~REQ_F_REISSUE; | |
1037 | ret2 = -EAGAIN; | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just | |
1042 | * retry them without IOCB_NOWAIT. | |
1043 | */ | |
1044 | if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) | |
1045 | ret2 = -EAGAIN; | |
1046 | /* no retry on NONBLOCK nor RWF_NOWAIT */ | |
1047 | if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) | |
1048 | goto done; | |
1049 | if (!force_nonblock || ret2 != -EAGAIN) { | |
1050 | /* IOPOLL retry should happen for io-wq threads */ | |
1051 | if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL)) | |
1052 | goto copy_iov; | |
4e17aaab SR |
1053 | |
1054 | if (ret2 != req->cqe.res && ret2 >= 0 && need_complete_io(req)) { | |
c86416c6 | 1055 | struct io_async_rw *io; |
4e17aaab | 1056 | |
1c849b48 SR |
1057 | trace_io_uring_short_write(req->ctx, kiocb->ki_pos - ret2, |
1058 | req->cqe.res, ret2); | |
1059 | ||
4e17aaab SR |
1060 | /* This is a partial write. The file pos has already been |
1061 | * updated, setup the async struct to complete the request | |
1062 | * in the worker. Also update bytes_done to account for | |
1063 | * the bytes already written. | |
1064 | */ | |
1065 | iov_iter_save_state(&s->iter, &s->iter_state); | |
1066 | ret = io_setup_async_rw(req, iovec, s, true); | |
1067 | ||
c86416c6 SR |
1068 | io = req->async_data; |
1069 | if (io) | |
1070 | io->bytes_done += ret2; | |
4e17aaab | 1071 | |
e053aaf4 | 1072 | if (kiocb->ki_flags & IOCB_WRITE) |
a370167f | 1073 | io_req_end_write(req); |
4e17aaab SR |
1074 | return ret ? ret : -EAGAIN; |
1075 | } | |
f3b44f92 | 1076 | done: |
df9830d8 | 1077 | ret = kiocb_done(req, ret2, issue_flags); |
f3b44f92 JA |
1078 | } else { |
1079 | copy_iov: | |
1080 | iov_iter_restore(&s->iter, &s->iter_state); | |
1081 | ret = io_setup_async_rw(req, iovec, s, false); | |
e053aaf4 JA |
1082 | if (!ret) { |
1083 | if (kiocb->ki_flags & IOCB_WRITE) | |
a370167f | 1084 | io_req_end_write(req); |
e053aaf4 JA |
1085 | return -EAGAIN; |
1086 | } | |
1087 | return ret; | |
f3b44f92 | 1088 | } |
f3b44f92 JA |
1089 | /* it's reportedly faster than delegating the null check to kfree() */ |
1090 | if (iovec) | |
1091 | kfree(iovec); | |
1092 | return ret; | |
1093 | } | |
1094 | ||
47b4c686 PB |
1095 | void io_rw_fail(struct io_kiocb *req) |
1096 | { | |
1097 | int res; | |
1098 | ||
1099 | res = io_fixup_rw_res(req, req->cqe.res); | |
1100 | io_req_set_res(req, res, req->cqe.flags); | |
1101 | } | |
1102 | ||
f3b44f92 JA |
1103 | int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) |
1104 | { | |
1105 | struct io_wq_work_node *pos, *start, *prev; | |
54bdd67d | 1106 | unsigned int poll_flags = 0; |
f3b44f92 JA |
1107 | DEFINE_IO_COMP_BATCH(iob); |
1108 | int nr_events = 0; | |
1109 | ||
1110 | /* | |
1111 | * Only spin for completions if we don't have multiple devices hanging | |
1112 | * off our complete list. | |
1113 | */ | |
1114 | if (ctx->poll_multi_queue || force_nonspin) | |
1115 | poll_flags |= BLK_POLL_ONESHOT; | |
1116 | ||
1117 | wq_list_for_each(pos, start, &ctx->iopoll_list) { | |
1118 | struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); | |
a1119fb0 | 1119 | struct file *file = req->file; |
f3b44f92 JA |
1120 | int ret; |
1121 | ||
1122 | /* | |
1123 | * Move completed and retryable entries to our local lists. | |
1124 | * If we find a request that requires polling, break out | |
1125 | * and complete those lists first, if we have entries there. | |
1126 | */ | |
1127 | if (READ_ONCE(req->iopoll_completed)) | |
1128 | break; | |
1129 | ||
5756a3a7 | 1130 | if (req->opcode == IORING_OP_URING_CMD) { |
a1119fb0 | 1131 | struct io_uring_cmd *ioucmd; |
5756a3a7 | 1132 | |
a1119fb0 | 1133 | ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); |
de97fcb3 JA |
1134 | ret = file->f_op->uring_cmd_iopoll(ioucmd, &iob, |
1135 | poll_flags); | |
a1119fb0 JA |
1136 | } else { |
1137 | struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw); | |
1138 | ||
1139 | ret = file->f_op->iopoll(&rw->kiocb, &iob, poll_flags); | |
1140 | } | |
f3b44f92 JA |
1141 | if (unlikely(ret < 0)) |
1142 | return ret; | |
1143 | else if (ret) | |
1144 | poll_flags |= BLK_POLL_ONESHOT; | |
1145 | ||
1146 | /* iopoll may have completed current req */ | |
1147 | if (!rq_list_empty(iob.req_list) || | |
1148 | READ_ONCE(req->iopoll_completed)) | |
1149 | break; | |
1150 | } | |
1151 | ||
1152 | if (!rq_list_empty(iob.req_list)) | |
1153 | iob.complete(&iob); | |
1154 | else if (!pos) | |
1155 | return 0; | |
1156 | ||
1157 | prev = start; | |
1158 | wq_list_for_each_resume(pos, prev) { | |
1159 | struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); | |
1160 | ||
1161 | /* order with io_complete_rw_iopoll(), e.g. ->result updates */ | |
1162 | if (!smp_load_acquire(&req->iopoll_completed)) | |
1163 | break; | |
1164 | nr_events++; | |
f3b44f92 | 1165 | req->cqe.flags = io_put_kbuf(req, 0); |
f3b44f92 | 1166 | } |
f3b44f92 JA |
1167 | if (unlikely(!nr_events)) |
1168 | return 0; | |
1169 | ||
f3b44f92 JA |
1170 | pos = start ? start->next : ctx->iopoll_list.first; |
1171 | wq_list_cut(&ctx->iopoll_list, prev, start); | |
ec26c225 PB |
1172 | |
1173 | if (WARN_ON_ONCE(!wq_list_empty(&ctx->submit_state.compl_reqs))) | |
1174 | return 0; | |
1175 | ctx->submit_state.compl_reqs.first = pos; | |
1176 | __io_submit_flush_completions(ctx); | |
f3b44f92 JA |
1177 | return nr_events; |
1178 | } |