Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
86db1e29 JA |
2 | /* |
3 | * Functions related to mapping data to requests | |
4 | */ | |
5 | #include <linux/kernel.h> | |
68db0cf1 | 6 | #include <linux/sched/task_stack.h> |
86db1e29 JA |
7 | #include <linux/module.h> |
8 | #include <linux/bio.h> | |
9 | #include <linux/blkdev.h> | |
26e49cfc | 10 | #include <linux/uio.h> |
86db1e29 JA |
11 | |
12 | #include "blk.h" | |
13 | ||
130879f1 | 14 | struct bio_map_data { |
f3256075 CH |
15 | bool is_our_pages : 1; |
16 | bool is_null_mapped : 1; | |
130879f1 CH |
17 | struct iov_iter iter; |
18 | struct iovec iov[]; | |
19 | }; | |
20 | ||
21 | static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data, | |
22 | gfp_t gfp_mask) | |
23 | { | |
24 | struct bio_map_data *bmd; | |
25 | ||
26 | if (data->nr_segs > UIO_MAXIOV) | |
27 | return NULL; | |
28 | ||
29 | bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask); | |
30 | if (!bmd) | |
31 | return NULL; | |
32 | memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs); | |
33 | bmd->iter = *data; | |
34 | bmd->iter.iov = bmd->iov; | |
35 | return bmd; | |
36 | } | |
37 | ||
38 | /** | |
39 | * bio_copy_from_iter - copy all pages from iov_iter to bio | |
40 | * @bio: The &struct bio which describes the I/O as destination | |
41 | * @iter: iov_iter as source | |
42 | * | |
43 | * Copy all pages from iov_iter to bio. | |
44 | * Returns 0 on success, or error on failure. | |
45 | */ | |
46 | static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter) | |
47 | { | |
48 | struct bio_vec *bvec; | |
49 | struct bvec_iter_all iter_all; | |
50 | ||
51 | bio_for_each_segment_all(bvec, bio, iter_all) { | |
52 | ssize_t ret; | |
53 | ||
54 | ret = copy_page_from_iter(bvec->bv_page, | |
55 | bvec->bv_offset, | |
56 | bvec->bv_len, | |
57 | iter); | |
58 | ||
59 | if (!iov_iter_count(iter)) | |
60 | break; | |
61 | ||
62 | if (ret < bvec->bv_len) | |
63 | return -EFAULT; | |
64 | } | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
69 | /** | |
70 | * bio_copy_to_iter - copy all pages from bio to iov_iter | |
71 | * @bio: The &struct bio which describes the I/O as source | |
72 | * @iter: iov_iter as destination | |
73 | * | |
74 | * Copy all pages from bio to iov_iter. | |
75 | * Returns 0 on success, or error on failure. | |
76 | */ | |
77 | static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter) | |
78 | { | |
79 | struct bio_vec *bvec; | |
80 | struct bvec_iter_all iter_all; | |
81 | ||
82 | bio_for_each_segment_all(bvec, bio, iter_all) { | |
83 | ssize_t ret; | |
84 | ||
85 | ret = copy_page_to_iter(bvec->bv_page, | |
86 | bvec->bv_offset, | |
87 | bvec->bv_len, | |
88 | &iter); | |
89 | ||
90 | if (!iov_iter_count(&iter)) | |
91 | break; | |
92 | ||
93 | if (ret < bvec->bv_len) | |
94 | return -EFAULT; | |
95 | } | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | /** | |
101 | * bio_uncopy_user - finish previously mapped bio | |
102 | * @bio: bio being terminated | |
103 | * | |
104 | * Free pages allocated from bio_copy_user_iov() and write back data | |
105 | * to user space in case of a read. | |
106 | */ | |
107 | static int bio_uncopy_user(struct bio *bio) | |
108 | { | |
109 | struct bio_map_data *bmd = bio->bi_private; | |
110 | int ret = 0; | |
111 | ||
f3256075 | 112 | if (!bmd || !bmd->is_null_mapped) { |
130879f1 CH |
113 | /* |
114 | * if we're in a workqueue, the request is orphaned, so | |
115 | * don't copy into a random user address space, just free | |
116 | * and return -EINTR so user space doesn't expect any data. | |
117 | */ | |
118 | if (!current->mm) | |
119 | ret = -EINTR; | |
120 | else if (bio_data_dir(bio) == READ) | |
121 | ret = bio_copy_to_iter(bio, bmd->iter); | |
122 | if (bmd->is_our_pages) | |
123 | bio_free_pages(bio); | |
124 | } | |
125 | kfree(bmd); | |
126 | bio_put(bio); | |
127 | return ret; | |
128 | } | |
129 | ||
130 | /** | |
131 | * bio_copy_user_iov - copy user data to bio | |
132 | * @q: destination block queue | |
133 | * @map_data: pointer to the rq_map_data holding pages (if necessary) | |
134 | * @iter: iovec iterator | |
135 | * @gfp_mask: memory allocation flags | |
136 | * | |
137 | * Prepares and returns a bio for indirect user io, bouncing data | |
138 | * to/from kernel pages as necessary. Must be paired with | |
139 | * call bio_uncopy_user() on io completion. | |
140 | */ | |
141 | static struct bio *bio_copy_user_iov(struct request_queue *q, | |
142 | struct rq_map_data *map_data, struct iov_iter *iter, | |
143 | gfp_t gfp_mask) | |
144 | { | |
145 | struct bio_map_data *bmd; | |
146 | struct page *page; | |
147 | struct bio *bio; | |
148 | int i = 0, ret; | |
149 | int nr_pages; | |
150 | unsigned int len = iter->count; | |
151 | unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; | |
152 | ||
153 | bmd = bio_alloc_map_data(iter, gfp_mask); | |
154 | if (!bmd) | |
155 | return ERR_PTR(-ENOMEM); | |
156 | ||
157 | /* | |
158 | * We need to do a deep copy of the iov_iter including the iovecs. | |
159 | * The caller provided iov might point to an on-stack or otherwise | |
160 | * shortlived one. | |
161 | */ | |
f3256075 | 162 | bmd->is_our_pages = !map_data; |
130879f1 CH |
163 | |
164 | nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); | |
165 | if (nr_pages > BIO_MAX_PAGES) | |
166 | nr_pages = BIO_MAX_PAGES; | |
167 | ||
168 | ret = -ENOMEM; | |
169 | bio = bio_kmalloc(gfp_mask, nr_pages); | |
170 | if (!bio) | |
171 | goto out_bmd; | |
172 | ||
173 | ret = 0; | |
174 | ||
175 | if (map_data) { | |
176 | nr_pages = 1 << map_data->page_order; | |
177 | i = map_data->offset / PAGE_SIZE; | |
178 | } | |
179 | while (len) { | |
180 | unsigned int bytes = PAGE_SIZE; | |
181 | ||
182 | bytes -= offset; | |
183 | ||
184 | if (bytes > len) | |
185 | bytes = len; | |
186 | ||
187 | if (map_data) { | |
188 | if (i == map_data->nr_entries * nr_pages) { | |
189 | ret = -ENOMEM; | |
190 | break; | |
191 | } | |
192 | ||
193 | page = map_data->pages[i / nr_pages]; | |
194 | page += (i % nr_pages); | |
195 | ||
196 | i++; | |
197 | } else { | |
198 | page = alloc_page(q->bounce_gfp | gfp_mask); | |
199 | if (!page) { | |
200 | ret = -ENOMEM; | |
201 | break; | |
202 | } | |
203 | } | |
204 | ||
205 | if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) { | |
206 | if (!map_data) | |
207 | __free_page(page); | |
208 | break; | |
209 | } | |
210 | ||
211 | len -= bytes; | |
212 | offset = 0; | |
213 | } | |
214 | ||
215 | if (ret) | |
216 | goto cleanup; | |
217 | ||
218 | if (map_data) | |
219 | map_data->offset += bio->bi_iter.bi_size; | |
220 | ||
221 | /* | |
222 | * success | |
223 | */ | |
224 | if ((iov_iter_rw(iter) == WRITE && | |
225 | (!map_data || !map_data->null_mapped)) || | |
226 | (map_data && map_data->from_user)) { | |
227 | ret = bio_copy_from_iter(bio, iter); | |
228 | if (ret) | |
229 | goto cleanup; | |
230 | } else { | |
231 | if (bmd->is_our_pages) | |
232 | zero_fill_bio(bio); | |
233 | iov_iter_advance(iter, bio->bi_iter.bi_size); | |
234 | } | |
235 | ||
236 | bio->bi_private = bmd; | |
237 | if (map_data && map_data->null_mapped) | |
f3256075 | 238 | bmd->is_null_mapped = true; |
130879f1 CH |
239 | return bio; |
240 | cleanup: | |
241 | if (!map_data) | |
242 | bio_free_pages(bio); | |
243 | bio_put(bio); | |
244 | out_bmd: | |
245 | kfree(bmd); | |
246 | return ERR_PTR(ret); | |
247 | } | |
248 | ||
249 | /** | |
250 | * bio_map_user_iov - map user iovec into bio | |
251 | * @q: the struct request_queue for the bio | |
252 | * @iter: iovec iterator | |
253 | * @gfp_mask: memory allocation flags | |
254 | * | |
255 | * Map the user space address into a bio suitable for io to a block | |
256 | * device. Returns an error pointer in case of error. | |
257 | */ | |
258 | static struct bio *bio_map_user_iov(struct request_queue *q, | |
259 | struct iov_iter *iter, gfp_t gfp_mask) | |
260 | { | |
e4581105 | 261 | unsigned int max_sectors = queue_max_hw_sectors(q); |
130879f1 CH |
262 | int j; |
263 | struct bio *bio; | |
264 | int ret; | |
265 | ||
266 | if (!iov_iter_count(iter)) | |
267 | return ERR_PTR(-EINVAL); | |
268 | ||
269 | bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES)); | |
270 | if (!bio) | |
271 | return ERR_PTR(-ENOMEM); | |
272 | ||
273 | while (iov_iter_count(iter)) { | |
274 | struct page **pages; | |
275 | ssize_t bytes; | |
276 | size_t offs, added = 0; | |
277 | int npages; | |
278 | ||
279 | bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs); | |
280 | if (unlikely(bytes <= 0)) { | |
281 | ret = bytes ? bytes : -EFAULT; | |
282 | goto out_unmap; | |
283 | } | |
284 | ||
285 | npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); | |
286 | ||
287 | if (unlikely(offs & queue_dma_alignment(q))) { | |
288 | ret = -EINVAL; | |
289 | j = 0; | |
290 | } else { | |
291 | for (j = 0; j < npages; j++) { | |
292 | struct page *page = pages[j]; | |
293 | unsigned int n = PAGE_SIZE - offs; | |
294 | bool same_page = false; | |
295 | ||
296 | if (n > bytes) | |
297 | n = bytes; | |
298 | ||
e4581105 CH |
299 | if (!bio_add_hw_page(q, bio, page, n, offs, |
300 | max_sectors, &same_page)) { | |
130879f1 CH |
301 | if (same_page) |
302 | put_page(page); | |
303 | break; | |
304 | } | |
305 | ||
306 | added += n; | |
307 | bytes -= n; | |
308 | offs = 0; | |
309 | } | |
310 | iov_iter_advance(iter, added); | |
311 | } | |
312 | /* | |
313 | * release the pages we didn't map into the bio, if any | |
314 | */ | |
315 | while (j < npages) | |
316 | put_page(pages[j++]); | |
317 | kvfree(pages); | |
318 | /* couldn't stuff something into bio? */ | |
319 | if (bytes) | |
320 | break; | |
321 | } | |
322 | ||
323 | bio_set_flag(bio, BIO_USER_MAPPED); | |
324 | ||
325 | /* | |
326 | * subtle -- if bio_map_user_iov() ended up bouncing a bio, | |
327 | * it would normally disappear when its bi_end_io is run. | |
328 | * however, we need it for the unmap, so grab an extra | |
329 | * reference to it | |
330 | */ | |
331 | bio_get(bio); | |
332 | return bio; | |
333 | ||
334 | out_unmap: | |
335 | bio_release_pages(bio, false); | |
336 | bio_put(bio); | |
337 | return ERR_PTR(ret); | |
338 | } | |
339 | ||
340 | /** | |
341 | * bio_unmap_user - unmap a bio | |
342 | * @bio: the bio being unmapped | |
343 | * | |
344 | * Unmap a bio previously mapped by bio_map_user_iov(). Must be called from | |
345 | * process context. | |
346 | * | |
347 | * bio_unmap_user() may sleep. | |
348 | */ | |
349 | static void bio_unmap_user(struct bio *bio) | |
350 | { | |
351 | bio_release_pages(bio, bio_data_dir(bio) == READ); | |
352 | bio_put(bio); | |
353 | bio_put(bio); | |
354 | } | |
355 | ||
356 | static void bio_invalidate_vmalloc_pages(struct bio *bio) | |
357 | { | |
358 | #ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE | |
359 | if (bio->bi_private && !op_is_write(bio_op(bio))) { | |
360 | unsigned long i, len = 0; | |
361 | ||
362 | for (i = 0; i < bio->bi_vcnt; i++) | |
363 | len += bio->bi_io_vec[i].bv_len; | |
364 | invalidate_kernel_vmap_range(bio->bi_private, len); | |
365 | } | |
366 | #endif | |
367 | } | |
368 | ||
369 | static void bio_map_kern_endio(struct bio *bio) | |
370 | { | |
371 | bio_invalidate_vmalloc_pages(bio); | |
372 | bio_put(bio); | |
373 | } | |
374 | ||
375 | /** | |
376 | * bio_map_kern - map kernel address into bio | |
377 | * @q: the struct request_queue for the bio | |
378 | * @data: pointer to buffer to map | |
379 | * @len: length in bytes | |
380 | * @gfp_mask: allocation flags for bio allocation | |
381 | * | |
382 | * Map the kernel address into a bio suitable for io to a block | |
383 | * device. Returns an error pointer in case of error. | |
384 | */ | |
385 | static struct bio *bio_map_kern(struct request_queue *q, void *data, | |
386 | unsigned int len, gfp_t gfp_mask) | |
387 | { | |
388 | unsigned long kaddr = (unsigned long)data; | |
389 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
390 | unsigned long start = kaddr >> PAGE_SHIFT; | |
391 | const int nr_pages = end - start; | |
392 | bool is_vmalloc = is_vmalloc_addr(data); | |
393 | struct page *page; | |
394 | int offset, i; | |
395 | struct bio *bio; | |
396 | ||
397 | bio = bio_kmalloc(gfp_mask, nr_pages); | |
398 | if (!bio) | |
399 | return ERR_PTR(-ENOMEM); | |
400 | ||
401 | if (is_vmalloc) { | |
402 | flush_kernel_vmap_range(data, len); | |
403 | bio->bi_private = data; | |
404 | } | |
405 | ||
406 | offset = offset_in_page(kaddr); | |
407 | for (i = 0; i < nr_pages; i++) { | |
408 | unsigned int bytes = PAGE_SIZE - offset; | |
409 | ||
410 | if (len <= 0) | |
411 | break; | |
412 | ||
413 | if (bytes > len) | |
414 | bytes = len; | |
415 | ||
416 | if (!is_vmalloc) | |
417 | page = virt_to_page(data); | |
418 | else | |
419 | page = vmalloc_to_page(data); | |
420 | if (bio_add_pc_page(q, bio, page, bytes, | |
421 | offset) < bytes) { | |
422 | /* we don't support partial mappings */ | |
423 | bio_put(bio); | |
424 | return ERR_PTR(-EINVAL); | |
425 | } | |
426 | ||
427 | data += bytes; | |
428 | len -= bytes; | |
429 | offset = 0; | |
430 | } | |
431 | ||
432 | bio->bi_end_io = bio_map_kern_endio; | |
433 | return bio; | |
434 | } | |
435 | ||
436 | static void bio_copy_kern_endio(struct bio *bio) | |
437 | { | |
438 | bio_free_pages(bio); | |
439 | bio_put(bio); | |
440 | } | |
441 | ||
442 | static void bio_copy_kern_endio_read(struct bio *bio) | |
443 | { | |
444 | char *p = bio->bi_private; | |
445 | struct bio_vec *bvec; | |
446 | struct bvec_iter_all iter_all; | |
447 | ||
448 | bio_for_each_segment_all(bvec, bio, iter_all) { | |
449 | memcpy(p, page_address(bvec->bv_page), bvec->bv_len); | |
450 | p += bvec->bv_len; | |
451 | } | |
452 | ||
453 | bio_copy_kern_endio(bio); | |
454 | } | |
455 | ||
456 | /** | |
457 | * bio_copy_kern - copy kernel address into bio | |
458 | * @q: the struct request_queue for the bio | |
459 | * @data: pointer to buffer to copy | |
460 | * @len: length in bytes | |
461 | * @gfp_mask: allocation flags for bio and page allocation | |
462 | * @reading: data direction is READ | |
463 | * | |
464 | * copy the kernel address into a bio suitable for io to a block | |
465 | * device. Returns an error pointer in case of error. | |
466 | */ | |
467 | static struct bio *bio_copy_kern(struct request_queue *q, void *data, | |
468 | unsigned int len, gfp_t gfp_mask, int reading) | |
469 | { | |
470 | unsigned long kaddr = (unsigned long)data; | |
471 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
472 | unsigned long start = kaddr >> PAGE_SHIFT; | |
473 | struct bio *bio; | |
474 | void *p = data; | |
475 | int nr_pages = 0; | |
476 | ||
477 | /* | |
478 | * Overflow, abort | |
479 | */ | |
480 | if (end < start) | |
481 | return ERR_PTR(-EINVAL); | |
482 | ||
483 | nr_pages = end - start; | |
484 | bio = bio_kmalloc(gfp_mask, nr_pages); | |
485 | if (!bio) | |
486 | return ERR_PTR(-ENOMEM); | |
487 | ||
488 | while (len) { | |
489 | struct page *page; | |
490 | unsigned int bytes = PAGE_SIZE; | |
491 | ||
492 | if (bytes > len) | |
493 | bytes = len; | |
494 | ||
495 | page = alloc_page(q->bounce_gfp | gfp_mask); | |
496 | if (!page) | |
497 | goto cleanup; | |
498 | ||
499 | if (!reading) | |
500 | memcpy(page_address(page), p, bytes); | |
501 | ||
502 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) | |
503 | break; | |
504 | ||
505 | len -= bytes; | |
506 | p += bytes; | |
507 | } | |
508 | ||
509 | if (reading) { | |
510 | bio->bi_end_io = bio_copy_kern_endio_read; | |
511 | bio->bi_private = data; | |
512 | } else { | |
513 | bio->bi_end_io = bio_copy_kern_endio; | |
514 | } | |
515 | ||
516 | return bio; | |
517 | ||
518 | cleanup: | |
519 | bio_free_pages(bio); | |
520 | bio_put(bio); | |
521 | return ERR_PTR(-ENOMEM); | |
522 | } | |
523 | ||
98d61d5b | 524 | /* |
0abc2a10 JA |
525 | * Append a bio to a passthrough request. Only works if the bio can be merged |
526 | * into the request based on the driver constraints. | |
98d61d5b | 527 | */ |
0abc2a10 | 528 | int blk_rq_append_bio(struct request *rq, struct bio **bio) |
86db1e29 | 529 | { |
0abc2a10 | 530 | struct bio *orig_bio = *bio; |
14ccb66b CH |
531 | struct bvec_iter iter; |
532 | struct bio_vec bv; | |
533 | unsigned int nr_segs = 0; | |
0abc2a10 JA |
534 | |
535 | blk_queue_bounce(rq->q, bio); | |
caa4b024 | 536 | |
14ccb66b CH |
537 | bio_for_each_bvec(bv, *bio, iter) |
538 | nr_segs++; | |
539 | ||
98d61d5b | 540 | if (!rq->bio) { |
14ccb66b | 541 | blk_rq_bio_prep(rq, *bio, nr_segs); |
98d61d5b | 542 | } else { |
14ccb66b | 543 | if (!ll_back_merge_fn(rq, *bio, nr_segs)) { |
0abc2a10 JA |
544 | if (orig_bio != *bio) { |
545 | bio_put(*bio); | |
546 | *bio = orig_bio; | |
547 | } | |
98d61d5b | 548 | return -EINVAL; |
0abc2a10 | 549 | } |
98d61d5b | 550 | |
0abc2a10 JA |
551 | rq->biotail->bi_next = *bio; |
552 | rq->biotail = *bio; | |
553 | rq->__data_len += (*bio)->bi_iter.bi_size; | |
a892c8d5 | 554 | bio_crypt_free_ctx(*bio); |
86db1e29 | 555 | } |
98d61d5b | 556 | |
86db1e29 JA |
557 | return 0; |
558 | } | |
98d61d5b | 559 | EXPORT_SYMBOL(blk_rq_append_bio); |
86db1e29 JA |
560 | |
561 | static int __blk_rq_unmap_user(struct bio *bio) | |
562 | { | |
563 | int ret = 0; | |
564 | ||
565 | if (bio) { | |
566 | if (bio_flagged(bio, BIO_USER_MAPPED)) | |
567 | bio_unmap_user(bio); | |
568 | else | |
569 | ret = bio_uncopy_user(bio); | |
570 | } | |
571 | ||
572 | return ret; | |
573 | } | |
574 | ||
4d6af73d CH |
575 | static int __blk_rq_map_user_iov(struct request *rq, |
576 | struct rq_map_data *map_data, struct iov_iter *iter, | |
577 | gfp_t gfp_mask, bool copy) | |
578 | { | |
579 | struct request_queue *q = rq->q; | |
580 | struct bio *bio, *orig_bio; | |
581 | int ret; | |
582 | ||
583 | if (copy) | |
584 | bio = bio_copy_user_iov(q, map_data, iter, gfp_mask); | |
585 | else | |
586 | bio = bio_map_user_iov(q, iter, gfp_mask); | |
587 | ||
588 | if (IS_ERR(bio)) | |
589 | return PTR_ERR(bio); | |
590 | ||
aebf526b CH |
591 | bio->bi_opf &= ~REQ_OP_MASK; |
592 | bio->bi_opf |= req_op(rq); | |
593 | ||
4d6af73d | 594 | orig_bio = bio; |
4d6af73d CH |
595 | |
596 | /* | |
597 | * We link the bounce buffer in and could have to traverse it | |
598 | * later so we have to get a ref to prevent it from being freed | |
599 | */ | |
0abc2a10 | 600 | ret = blk_rq_append_bio(rq, &bio); |
4d6af73d | 601 | if (ret) { |
4d6af73d | 602 | __blk_rq_unmap_user(orig_bio); |
4d6af73d CH |
603 | return ret; |
604 | } | |
0abc2a10 | 605 | bio_get(bio); |
4d6af73d CH |
606 | |
607 | return 0; | |
608 | } | |
609 | ||
86db1e29 | 610 | /** |
aebf526b | 611 | * blk_rq_map_user_iov - map user data to a request, for passthrough requests |
86db1e29 JA |
612 | * @q: request queue where request should be inserted |
613 | * @rq: request to map data to | |
152e283f | 614 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
26e49cfc | 615 | * @iter: iovec iterator |
a3bce90e | 616 | * @gfp_mask: memory allocation flags |
86db1e29 JA |
617 | * |
618 | * Description: | |
710027a4 | 619 | * Data will be mapped directly for zero copy I/O, if possible. Otherwise |
86db1e29 JA |
620 | * a kernel bounce buffer is used. |
621 | * | |
710027a4 | 622 | * A matching blk_rq_unmap_user() must be issued at the end of I/O, while |
86db1e29 JA |
623 | * still in process context. |
624 | * | |
625 | * Note: The mapped bio may need to be bounced through blk_queue_bounce() | |
626 | * before being submitted to the device, as pages mapped may be out of | |
627 | * reach. It's the callers responsibility to make sure this happens. The | |
628 | * original bio must be passed back in to blk_rq_unmap_user() for proper | |
629 | * unmapping. | |
630 | */ | |
631 | int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, | |
26e49cfc KO |
632 | struct rq_map_data *map_data, |
633 | const struct iov_iter *iter, gfp_t gfp_mask) | |
86db1e29 | 634 | { |
357f435d AV |
635 | bool copy = false; |
636 | unsigned long align = q->dma_pad_mask | queue_dma_alignment(q); | |
4d6af73d CH |
637 | struct bio *bio = NULL; |
638 | struct iov_iter i; | |
69e0927b | 639 | int ret = -EINVAL; |
86db1e29 | 640 | |
a0ac402c LT |
641 | if (!iter_is_iovec(iter)) |
642 | goto fail; | |
643 | ||
357f435d AV |
644 | if (map_data) |
645 | copy = true; | |
646 | else if (iov_iter_alignment(iter) & align) | |
647 | copy = true; | |
648 | else if (queue_virt_boundary(q)) | |
649 | copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter); | |
afdc1a78 | 650 | |
4d6af73d CH |
651 | i = *iter; |
652 | do { | |
653 | ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy); | |
654 | if (ret) | |
655 | goto unmap_rq; | |
656 | if (!bio) | |
657 | bio = rq->bio; | |
658 | } while (iov_iter_count(&i)); | |
86db1e29 | 659 | |
86db1e29 | 660 | return 0; |
4d6af73d CH |
661 | |
662 | unmap_rq: | |
3b7995a9 | 663 | blk_rq_unmap_user(bio); |
a0ac402c | 664 | fail: |
4d6af73d | 665 | rq->bio = NULL; |
69e0927b | 666 | return ret; |
86db1e29 | 667 | } |
152e283f | 668 | EXPORT_SYMBOL(blk_rq_map_user_iov); |
86db1e29 | 669 | |
ddad8dd0 CH |
670 | int blk_rq_map_user(struct request_queue *q, struct request *rq, |
671 | struct rq_map_data *map_data, void __user *ubuf, | |
672 | unsigned long len, gfp_t gfp_mask) | |
673 | { | |
26e49cfc KO |
674 | struct iovec iov; |
675 | struct iov_iter i; | |
8f7e885a | 676 | int ret = import_single_range(rq_data_dir(rq), ubuf, len, &iov, &i); |
ddad8dd0 | 677 | |
8f7e885a AV |
678 | if (unlikely(ret < 0)) |
679 | return ret; | |
ddad8dd0 | 680 | |
26e49cfc | 681 | return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask); |
ddad8dd0 CH |
682 | } |
683 | EXPORT_SYMBOL(blk_rq_map_user); | |
684 | ||
86db1e29 JA |
685 | /** |
686 | * blk_rq_unmap_user - unmap a request with user data | |
687 | * @bio: start of bio list | |
688 | * | |
689 | * Description: | |
690 | * Unmap a rq previously mapped by blk_rq_map_user(). The caller must | |
691 | * supply the original rq->bio from the blk_rq_map_user() return, since | |
710027a4 | 692 | * the I/O completion may have changed rq->bio. |
86db1e29 JA |
693 | */ |
694 | int blk_rq_unmap_user(struct bio *bio) | |
695 | { | |
696 | struct bio *mapped_bio; | |
697 | int ret = 0, ret2; | |
698 | ||
699 | while (bio) { | |
700 | mapped_bio = bio; | |
701 | if (unlikely(bio_flagged(bio, BIO_BOUNCED))) | |
702 | mapped_bio = bio->bi_private; | |
703 | ||
704 | ret2 = __blk_rq_unmap_user(mapped_bio); | |
705 | if (ret2 && !ret) | |
706 | ret = ret2; | |
707 | ||
708 | mapped_bio = bio; | |
709 | bio = bio->bi_next; | |
710 | bio_put(mapped_bio); | |
711 | } | |
712 | ||
713 | return ret; | |
714 | } | |
86db1e29 JA |
715 | EXPORT_SYMBOL(blk_rq_unmap_user); |
716 | ||
717 | /** | |
aebf526b | 718 | * blk_rq_map_kern - map kernel data to a request, for passthrough requests |
86db1e29 JA |
719 | * @q: request queue where request should be inserted |
720 | * @rq: request to fill | |
721 | * @kbuf: the kernel buffer | |
722 | * @len: length of user data | |
723 | * @gfp_mask: memory allocation flags | |
68154e90 FT |
724 | * |
725 | * Description: | |
726 | * Data will be mapped directly if possible. Otherwise a bounce | |
e227867f | 727 | * buffer is used. Can be called multiple times to append multiple |
3a5a3927 | 728 | * buffers. |
86db1e29 JA |
729 | */ |
730 | int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, | |
731 | unsigned int len, gfp_t gfp_mask) | |
732 | { | |
68154e90 | 733 | int reading = rq_data_dir(rq) == READ; |
14417799 | 734 | unsigned long addr = (unsigned long) kbuf; |
0abc2a10 | 735 | struct bio *bio, *orig_bio; |
3a5a3927 | 736 | int ret; |
86db1e29 | 737 | |
ae03bf63 | 738 | if (len > (queue_max_hw_sectors(q) << 9)) |
86db1e29 JA |
739 | return -EINVAL; |
740 | if (!len || !kbuf) | |
741 | return -EINVAL; | |
742 | ||
e64a0e16 | 743 | if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf)) |
68154e90 FT |
744 | bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading); |
745 | else | |
746 | bio = bio_map_kern(q, kbuf, len, gfp_mask); | |
747 | ||
86db1e29 JA |
748 | if (IS_ERR(bio)) |
749 | return PTR_ERR(bio); | |
750 | ||
aebf526b CH |
751 | bio->bi_opf &= ~REQ_OP_MASK; |
752 | bio->bi_opf |= req_op(rq); | |
86db1e29 | 753 | |
0abc2a10 JA |
754 | orig_bio = bio; |
755 | ret = blk_rq_append_bio(rq, &bio); | |
3a5a3927 JB |
756 | if (unlikely(ret)) { |
757 | /* request is too big */ | |
0abc2a10 | 758 | bio_put(orig_bio); |
3a5a3927 JB |
759 | return ret; |
760 | } | |
761 | ||
86db1e29 JA |
762 | return 0; |
763 | } | |
86db1e29 | 764 | EXPORT_SYMBOL(blk_rq_map_kern); |