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 | ||
3310eeba | 112 | if (!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); | |
130879f1 CH |
126 | return ret; |
127 | } | |
128 | ||
7589ad67 CH |
129 | static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, |
130 | struct iov_iter *iter, gfp_t gfp_mask) | |
130879f1 CH |
131 | { |
132 | struct bio_map_data *bmd; | |
133 | struct page *page; | |
393bb12e | 134 | struct bio *bio; |
130879f1 CH |
135 | int i = 0, ret; |
136 | int nr_pages; | |
137 | unsigned int len = iter->count; | |
138 | unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; | |
139 | ||
140 | bmd = bio_alloc_map_data(iter, gfp_mask); | |
141 | if (!bmd) | |
7589ad67 | 142 | return -ENOMEM; |
130879f1 CH |
143 | |
144 | /* | |
145 | * We need to do a deep copy of the iov_iter including the iovecs. | |
146 | * The caller provided iov might point to an on-stack or otherwise | |
147 | * shortlived one. | |
148 | */ | |
f3256075 | 149 | bmd->is_our_pages = !map_data; |
03859717 | 150 | bmd->is_null_mapped = (map_data && map_data->null_mapped); |
130879f1 | 151 | |
5f7136db | 152 | nr_pages = bio_max_segs(DIV_ROUND_UP(offset + len, PAGE_SIZE)); |
130879f1 CH |
153 | |
154 | ret = -ENOMEM; | |
066ff571 | 155 | bio = bio_kmalloc(nr_pages, gfp_mask); |
130879f1 CH |
156 | if (!bio) |
157 | goto out_bmd; | |
066ff571 | 158 | bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, req_op(rq)); |
130879f1 CH |
159 | |
160 | if (map_data) { | |
f5d632d1 | 161 | nr_pages = 1U << map_data->page_order; |
130879f1 CH |
162 | i = map_data->offset / PAGE_SIZE; |
163 | } | |
164 | while (len) { | |
165 | unsigned int bytes = PAGE_SIZE; | |
166 | ||
167 | bytes -= offset; | |
168 | ||
169 | if (bytes > len) | |
170 | bytes = len; | |
171 | ||
172 | if (map_data) { | |
173 | if (i == map_data->nr_entries * nr_pages) { | |
174 | ret = -ENOMEM; | |
7589ad67 | 175 | goto cleanup; |
130879f1 CH |
176 | } |
177 | ||
178 | page = map_data->pages[i / nr_pages]; | |
179 | page += (i % nr_pages); | |
180 | ||
181 | i++; | |
182 | } else { | |
ce288e05 | 183 | page = alloc_page(GFP_NOIO | gfp_mask); |
130879f1 CH |
184 | if (!page) { |
185 | ret = -ENOMEM; | |
7589ad67 | 186 | goto cleanup; |
130879f1 CH |
187 | } |
188 | } | |
189 | ||
7589ad67 | 190 | if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) { |
130879f1 CH |
191 | if (!map_data) |
192 | __free_page(page); | |
193 | break; | |
194 | } | |
195 | ||
196 | len -= bytes; | |
197 | offset = 0; | |
198 | } | |
199 | ||
130879f1 CH |
200 | if (map_data) |
201 | map_data->offset += bio->bi_iter.bi_size; | |
202 | ||
203 | /* | |
204 | * success | |
205 | */ | |
206 | if ((iov_iter_rw(iter) == WRITE && | |
207 | (!map_data || !map_data->null_mapped)) || | |
208 | (map_data && map_data->from_user)) { | |
209 | ret = bio_copy_from_iter(bio, iter); | |
210 | if (ret) | |
211 | goto cleanup; | |
212 | } else { | |
213 | if (bmd->is_our_pages) | |
214 | zero_fill_bio(bio); | |
215 | iov_iter_advance(iter, bio->bi_iter.bi_size); | |
216 | } | |
217 | ||
218 | bio->bi_private = bmd; | |
7589ad67 | 219 | |
393bb12e | 220 | ret = blk_rq_append_bio(rq, bio); |
7589ad67 CH |
221 | if (ret) |
222 | goto cleanup; | |
7589ad67 | 223 | return 0; |
130879f1 CH |
224 | cleanup: |
225 | if (!map_data) | |
226 | bio_free_pages(bio); | |
066ff571 CH |
227 | bio_uninit(bio); |
228 | kfree(bio); | |
130879f1 CH |
229 | out_bmd: |
230 | kfree(bmd); | |
7589ad67 | 231 | return ret; |
130879f1 CH |
232 | } |
233 | ||
32f1c71b | 234 | static void blk_mq_map_bio_put(struct bio *bio) |
8af870aa JA |
235 | { |
236 | if (bio->bi_opf & REQ_ALLOC_CACHE) { | |
237 | bio_put(bio); | |
238 | } else { | |
239 | bio_uninit(bio); | |
240 | kfree(bio); | |
241 | } | |
242 | } | |
243 | ||
ab89e8e7 KJ |
244 | static struct bio *blk_rq_map_bio_alloc(struct request *rq, |
245 | unsigned int nr_vecs, gfp_t gfp_mask) | |
130879f1 | 246 | { |
393bb12e | 247 | struct bio *bio; |
130879f1 | 248 | |
8af870aa JA |
249 | if (rq->cmd_flags & REQ_POLLED) { |
250 | blk_opf_t opf = rq->cmd_flags | REQ_ALLOC_CACHE; | |
251 | ||
252 | bio = bio_alloc_bioset(NULL, nr_vecs, opf, gfp_mask, | |
253 | &fs_bio_set); | |
254 | if (!bio) | |
ab89e8e7 | 255 | return NULL; |
8af870aa JA |
256 | } else { |
257 | bio = bio_kmalloc(nr_vecs, gfp_mask); | |
258 | if (!bio) | |
ab89e8e7 | 259 | return NULL; |
8af870aa JA |
260 | bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq)); |
261 | } | |
ab89e8e7 KJ |
262 | return bio; |
263 | } | |
264 | ||
265 | static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, | |
266 | gfp_t gfp_mask) | |
267 | { | |
268 | unsigned int max_sectors = queue_max_hw_sectors(rq->q); | |
269 | unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS); | |
270 | struct bio *bio; | |
271 | int ret; | |
272 | int j; | |
273 | ||
274 | if (!iov_iter_count(iter)) | |
275 | return -EINVAL; | |
276 | ||
277 | bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask); | |
278 | if (bio == NULL) | |
279 | return -ENOMEM; | |
130879f1 CH |
280 | |
281 | while (iov_iter_count(iter)) { | |
e88811bc | 282 | struct page **pages, *stack_pages[UIO_FASTIOV]; |
130879f1 | 283 | ssize_t bytes; |
91e5adda | 284 | size_t offs; |
130879f1 CH |
285 | int npages; |
286 | ||
e88811bc JA |
287 | if (nr_vecs <= ARRAY_SIZE(stack_pages)) { |
288 | pages = stack_pages; | |
289 | bytes = iov_iter_get_pages2(iter, pages, LONG_MAX, | |
290 | nr_vecs, &offs); | |
291 | } else { | |
292 | bytes = iov_iter_get_pages_alloc2(iter, &pages, | |
293 | LONG_MAX, &offs); | |
294 | } | |
130879f1 CH |
295 | if (unlikely(bytes <= 0)) { |
296 | ret = bytes ? bytes : -EFAULT; | |
297 | goto out_unmap; | |
298 | } | |
299 | ||
300 | npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); | |
301 | ||
7ab89db9 | 302 | if (unlikely(offs & queue_dma_alignment(rq->q))) |
130879f1 | 303 | j = 0; |
7ab89db9 | 304 | else { |
130879f1 CH |
305 | for (j = 0; j < npages; j++) { |
306 | struct page *page = pages[j]; | |
307 | unsigned int n = PAGE_SIZE - offs; | |
308 | bool same_page = false; | |
309 | ||
310 | if (n > bytes) | |
311 | n = bytes; | |
312 | ||
7589ad67 | 313 | if (!bio_add_hw_page(rq->q, bio, page, n, offs, |
e4581105 | 314 | max_sectors, &same_page)) { |
130879f1 CH |
315 | if (same_page) |
316 | put_page(page); | |
317 | break; | |
318 | } | |
319 | ||
130879f1 CH |
320 | bytes -= n; |
321 | offs = 0; | |
322 | } | |
130879f1 CH |
323 | } |
324 | /* | |
325 | * release the pages we didn't map into the bio, if any | |
326 | */ | |
327 | while (j < npages) | |
328 | put_page(pages[j++]); | |
e88811bc JA |
329 | if (pages != stack_pages) |
330 | kvfree(pages); | |
130879f1 | 331 | /* couldn't stuff something into bio? */ |
480cb846 AV |
332 | if (bytes) { |
333 | iov_iter_revert(iter, bytes); | |
130879f1 | 334 | break; |
480cb846 | 335 | } |
130879f1 CH |
336 | } |
337 | ||
393bb12e | 338 | ret = blk_rq_append_bio(rq, bio); |
7589ad67 | 339 | if (ret) |
393bb12e | 340 | goto out_unmap; |
7589ad67 CH |
341 | return 0; |
342 | ||
130879f1 CH |
343 | out_unmap: |
344 | bio_release_pages(bio, false); | |
32f1c71b | 345 | blk_mq_map_bio_put(bio); |
7589ad67 | 346 | return ret; |
130879f1 CH |
347 | } |
348 | ||
130879f1 CH |
349 | static void bio_invalidate_vmalloc_pages(struct bio *bio) |
350 | { | |
f358afc5 | 351 | #ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE |
130879f1 CH |
352 | if (bio->bi_private && !op_is_write(bio_op(bio))) { |
353 | unsigned long i, len = 0; | |
354 | ||
355 | for (i = 0; i < bio->bi_vcnt; i++) | |
356 | len += bio->bi_io_vec[i].bv_len; | |
357 | invalidate_kernel_vmap_range(bio->bi_private, len); | |
358 | } | |
359 | #endif | |
360 | } | |
361 | ||
362 | static void bio_map_kern_endio(struct bio *bio) | |
363 | { | |
364 | bio_invalidate_vmalloc_pages(bio); | |
066ff571 CH |
365 | bio_uninit(bio); |
366 | kfree(bio); | |
130879f1 CH |
367 | } |
368 | ||
369 | /** | |
370 | * bio_map_kern - map kernel address into bio | |
371 | * @q: the struct request_queue for the bio | |
372 | * @data: pointer to buffer to map | |
373 | * @len: length in bytes | |
374 | * @gfp_mask: allocation flags for bio allocation | |
375 | * | |
376 | * Map the kernel address into a bio suitable for io to a block | |
377 | * device. Returns an error pointer in case of error. | |
378 | */ | |
379 | static struct bio *bio_map_kern(struct request_queue *q, void *data, | |
380 | unsigned int len, gfp_t gfp_mask) | |
381 | { | |
382 | unsigned long kaddr = (unsigned long)data; | |
383 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
384 | unsigned long start = kaddr >> PAGE_SHIFT; | |
385 | const int nr_pages = end - start; | |
386 | bool is_vmalloc = is_vmalloc_addr(data); | |
387 | struct page *page; | |
388 | int offset, i; | |
389 | struct bio *bio; | |
390 | ||
066ff571 | 391 | bio = bio_kmalloc(nr_pages, gfp_mask); |
130879f1 CH |
392 | if (!bio) |
393 | return ERR_PTR(-ENOMEM); | |
066ff571 | 394 | bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0); |
130879f1 CH |
395 | |
396 | if (is_vmalloc) { | |
397 | flush_kernel_vmap_range(data, len); | |
398 | bio->bi_private = data; | |
399 | } | |
400 | ||
401 | offset = offset_in_page(kaddr); | |
402 | for (i = 0; i < nr_pages; i++) { | |
403 | unsigned int bytes = PAGE_SIZE - offset; | |
404 | ||
405 | if (len <= 0) | |
406 | break; | |
407 | ||
408 | if (bytes > len) | |
409 | bytes = len; | |
410 | ||
411 | if (!is_vmalloc) | |
412 | page = virt_to_page(data); | |
413 | else | |
414 | page = vmalloc_to_page(data); | |
415 | if (bio_add_pc_page(q, bio, page, bytes, | |
416 | offset) < bytes) { | |
417 | /* we don't support partial mappings */ | |
066ff571 CH |
418 | bio_uninit(bio); |
419 | kfree(bio); | |
130879f1 CH |
420 | return ERR_PTR(-EINVAL); |
421 | } | |
422 | ||
423 | data += bytes; | |
424 | len -= bytes; | |
425 | offset = 0; | |
426 | } | |
427 | ||
428 | bio->bi_end_io = bio_map_kern_endio; | |
429 | return bio; | |
430 | } | |
431 | ||
432 | static void bio_copy_kern_endio(struct bio *bio) | |
433 | { | |
434 | bio_free_pages(bio); | |
066ff571 CH |
435 | bio_uninit(bio); |
436 | kfree(bio); | |
130879f1 CH |
437 | } |
438 | ||
439 | static void bio_copy_kern_endio_read(struct bio *bio) | |
440 | { | |
441 | char *p = bio->bi_private; | |
442 | struct bio_vec *bvec; | |
443 | struct bvec_iter_all iter_all; | |
444 | ||
445 | bio_for_each_segment_all(bvec, bio, iter_all) { | |
d24920e2 | 446 | memcpy_from_bvec(p, bvec); |
130879f1 CH |
447 | p += bvec->bv_len; |
448 | } | |
449 | ||
450 | bio_copy_kern_endio(bio); | |
451 | } | |
452 | ||
453 | /** | |
454 | * bio_copy_kern - copy kernel address into bio | |
455 | * @q: the struct request_queue for the bio | |
456 | * @data: pointer to buffer to copy | |
457 | * @len: length in bytes | |
458 | * @gfp_mask: allocation flags for bio and page allocation | |
459 | * @reading: data direction is READ | |
460 | * | |
461 | * copy the kernel address into a bio suitable for io to a block | |
462 | * device. Returns an error pointer in case of error. | |
463 | */ | |
464 | static struct bio *bio_copy_kern(struct request_queue *q, void *data, | |
465 | unsigned int len, gfp_t gfp_mask, int reading) | |
466 | { | |
467 | unsigned long kaddr = (unsigned long)data; | |
468 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
469 | unsigned long start = kaddr >> PAGE_SHIFT; | |
470 | struct bio *bio; | |
471 | void *p = data; | |
472 | int nr_pages = 0; | |
473 | ||
474 | /* | |
475 | * Overflow, abort | |
476 | */ | |
477 | if (end < start) | |
478 | return ERR_PTR(-EINVAL); | |
479 | ||
480 | nr_pages = end - start; | |
066ff571 | 481 | bio = bio_kmalloc(nr_pages, gfp_mask); |
130879f1 CH |
482 | if (!bio) |
483 | return ERR_PTR(-ENOMEM); | |
066ff571 | 484 | bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0); |
130879f1 CH |
485 | |
486 | while (len) { | |
487 | struct page *page; | |
488 | unsigned int bytes = PAGE_SIZE; | |
489 | ||
490 | if (bytes > len) | |
491 | bytes = len; | |
492 | ||
cc8f7fe1 | 493 | page = alloc_page(GFP_NOIO | __GFP_ZERO | gfp_mask); |
130879f1 CH |
494 | if (!page) |
495 | goto cleanup; | |
496 | ||
497 | if (!reading) | |
498 | memcpy(page_address(page), p, bytes); | |
499 | ||
500 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) | |
501 | break; | |
502 | ||
503 | len -= bytes; | |
504 | p += bytes; | |
505 | } | |
506 | ||
507 | if (reading) { | |
508 | bio->bi_end_io = bio_copy_kern_endio_read; | |
509 | bio->bi_private = data; | |
510 | } else { | |
511 | bio->bi_end_io = bio_copy_kern_endio; | |
512 | } | |
513 | ||
514 | return bio; | |
515 | ||
516 | cleanup: | |
517 | bio_free_pages(bio); | |
066ff571 CH |
518 | bio_uninit(bio); |
519 | kfree(bio); | |
130879f1 CH |
520 | return ERR_PTR(-ENOMEM); |
521 | } | |
522 | ||
98d61d5b | 523 | /* |
0abc2a10 JA |
524 | * Append a bio to a passthrough request. Only works if the bio can be merged |
525 | * into the request based on the driver constraints. | |
98d61d5b | 526 | */ |
393bb12e | 527 | int blk_rq_append_bio(struct request *rq, struct bio *bio) |
86db1e29 | 528 | { |
14ccb66b CH |
529 | struct bvec_iter iter; |
530 | struct bio_vec bv; | |
531 | unsigned int nr_segs = 0; | |
0abc2a10 | 532 | |
393bb12e | 533 | bio_for_each_bvec(bv, bio, iter) |
14ccb66b CH |
534 | nr_segs++; |
535 | ||
98d61d5b | 536 | if (!rq->bio) { |
393bb12e | 537 | blk_rq_bio_prep(rq, bio, nr_segs); |
98d61d5b | 538 | } else { |
393bb12e | 539 | if (!ll_back_merge_fn(rq, bio, nr_segs)) |
98d61d5b | 540 | return -EINVAL; |
393bb12e CH |
541 | rq->biotail->bi_next = bio; |
542 | rq->biotail = bio; | |
543 | rq->__data_len += (bio)->bi_iter.bi_size; | |
544 | bio_crypt_free_ctx(bio); | |
86db1e29 | 545 | } |
98d61d5b | 546 | |
86db1e29 JA |
547 | return 0; |
548 | } | |
98d61d5b | 549 | EXPORT_SYMBOL(blk_rq_append_bio); |
86db1e29 | 550 | |
37987547 KJ |
551 | /* Prepare bio for passthrough IO given ITER_BVEC iter */ |
552 | static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter) | |
553 | { | |
554 | struct request_queue *q = rq->q; | |
555 | size_t nr_iter = iov_iter_count(iter); | |
556 | size_t nr_segs = iter->nr_segs; | |
557 | struct bio_vec *bvecs, *bvprvp = NULL; | |
aa261f20 | 558 | const struct queue_limits *lim = &q->limits; |
37987547 KJ |
559 | unsigned int nsegs = 0, bytes = 0; |
560 | struct bio *bio; | |
561 | size_t i; | |
562 | ||
563 | if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q)) | |
564 | return -EINVAL; | |
565 | if (nr_segs > queue_max_segments(q)) | |
566 | return -EINVAL; | |
567 | ||
568 | /* no iovecs to alloc, as we already have a BVEC iterator */ | |
569 | bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL); | |
570 | if (bio == NULL) | |
571 | return -ENOMEM; | |
572 | ||
573 | bio_iov_bvec_set(bio, (struct iov_iter *)iter); | |
574 | blk_rq_bio_prep(rq, bio, nr_segs); | |
575 | ||
576 | /* loop to perform a bunch of sanity checks */ | |
577 | bvecs = (struct bio_vec *)iter->bvec; | |
578 | for (i = 0; i < nr_segs; i++) { | |
579 | struct bio_vec *bv = &bvecs[i]; | |
580 | ||
581 | /* | |
582 | * If the queue doesn't support SG gaps and adding this | |
583 | * offset would create a gap, fallback to copy. | |
584 | */ | |
585 | if (bvprvp && bvec_gap_to_prev(lim, bvprvp, bv->bv_offset)) { | |
586 | blk_mq_map_bio_put(bio); | |
587 | return -EREMOTEIO; | |
588 | } | |
589 | /* check full condition */ | |
590 | if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len) | |
591 | goto put_bio; | |
592 | if (bytes + bv->bv_len > nr_iter) | |
593 | goto put_bio; | |
594 | if (bv->bv_offset + bv->bv_len > PAGE_SIZE) | |
595 | goto put_bio; | |
596 | ||
597 | nsegs++; | |
598 | bytes += bv->bv_len; | |
599 | bvprvp = bv; | |
600 | } | |
601 | return 0; | |
602 | put_bio: | |
603 | blk_mq_map_bio_put(bio); | |
604 | return -EINVAL; | |
605 | } | |
606 | ||
86db1e29 | 607 | /** |
aebf526b | 608 | * blk_rq_map_user_iov - map user data to a request, for passthrough requests |
86db1e29 JA |
609 | * @q: request queue where request should be inserted |
610 | * @rq: request to map data to | |
152e283f | 611 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
26e49cfc | 612 | * @iter: iovec iterator |
a3bce90e | 613 | * @gfp_mask: memory allocation flags |
86db1e29 JA |
614 | * |
615 | * Description: | |
710027a4 | 616 | * Data will be mapped directly for zero copy I/O, if possible. Otherwise |
86db1e29 JA |
617 | * a kernel bounce buffer is used. |
618 | * | |
710027a4 | 619 | * A matching blk_rq_unmap_user() must be issued at the end of I/O, while |
86db1e29 | 620 | * still in process context. |
86db1e29 JA |
621 | */ |
622 | int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, | |
26e49cfc KO |
623 | struct rq_map_data *map_data, |
624 | const struct iov_iter *iter, gfp_t gfp_mask) | |
86db1e29 | 625 | { |
37987547 | 626 | bool copy = false, map_bvec = false; |
357f435d | 627 | unsigned long align = q->dma_pad_mask | queue_dma_alignment(q); |
4d6af73d CH |
628 | struct bio *bio = NULL; |
629 | struct iov_iter i; | |
69e0927b | 630 | int ret = -EINVAL; |
86db1e29 | 631 | |
357f435d AV |
632 | if (map_data) |
633 | copy = true; | |
393bb12e CH |
634 | else if (blk_queue_may_bounce(q)) |
635 | copy = true; | |
357f435d AV |
636 | else if (iov_iter_alignment(iter) & align) |
637 | copy = true; | |
37987547 KJ |
638 | else if (iov_iter_is_bvec(iter)) |
639 | map_bvec = true; | |
640 | else if (!iter_is_iovec(iter)) | |
641 | copy = true; | |
357f435d AV |
642 | else if (queue_virt_boundary(q)) |
643 | copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter); | |
afdc1a78 | 644 | |
37987547 KJ |
645 | if (map_bvec) { |
646 | ret = blk_rq_map_user_bvec(rq, iter); | |
647 | if (!ret) | |
648 | return 0; | |
649 | if (ret != -EREMOTEIO) | |
650 | goto fail; | |
651 | /* fall back to copying the data on limits mismatches */ | |
652 | copy = true; | |
653 | } | |
654 | ||
4d6af73d CH |
655 | i = *iter; |
656 | do { | |
7589ad67 CH |
657 | if (copy) |
658 | ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask); | |
659 | else | |
660 | ret = bio_map_user_iov(rq, &i, gfp_mask); | |
4d6af73d CH |
661 | if (ret) |
662 | goto unmap_rq; | |
663 | if (!bio) | |
664 | bio = rq->bio; | |
665 | } while (iov_iter_count(&i)); | |
86db1e29 | 666 | |
86db1e29 | 667 | return 0; |
4d6af73d CH |
668 | |
669 | unmap_rq: | |
3b7995a9 | 670 | blk_rq_unmap_user(bio); |
a0ac402c | 671 | fail: |
4d6af73d | 672 | rq->bio = NULL; |
69e0927b | 673 | return ret; |
86db1e29 | 674 | } |
152e283f | 675 | EXPORT_SYMBOL(blk_rq_map_user_iov); |
86db1e29 | 676 | |
ddad8dd0 CH |
677 | int blk_rq_map_user(struct request_queue *q, struct request *rq, |
678 | struct rq_map_data *map_data, void __user *ubuf, | |
679 | unsigned long len, gfp_t gfp_mask) | |
680 | { | |
26e49cfc KO |
681 | struct iovec iov; |
682 | struct iov_iter i; | |
8f7e885a | 683 | int ret = import_single_range(rq_data_dir(rq), ubuf, len, &iov, &i); |
ddad8dd0 | 684 | |
8f7e885a AV |
685 | if (unlikely(ret < 0)) |
686 | return ret; | |
ddad8dd0 | 687 | |
26e49cfc | 688 | return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask); |
ddad8dd0 CH |
689 | } |
690 | EXPORT_SYMBOL(blk_rq_map_user); | |
691 | ||
55765402 AG |
692 | int blk_rq_map_user_io(struct request *req, struct rq_map_data *map_data, |
693 | void __user *ubuf, unsigned long buf_len, gfp_t gfp_mask, | |
694 | bool vec, int iov_count, bool check_iter_count, int rw) | |
695 | { | |
696 | int ret = 0; | |
697 | ||
698 | if (vec) { | |
699 | struct iovec fast_iov[UIO_FASTIOV]; | |
700 | struct iovec *iov = fast_iov; | |
701 | struct iov_iter iter; | |
702 | ||
703 | ret = import_iovec(rw, ubuf, iov_count ? iov_count : buf_len, | |
704 | UIO_FASTIOV, &iov, &iter); | |
705 | if (ret < 0) | |
706 | return ret; | |
707 | ||
708 | if (iov_count) { | |
709 | /* SG_IO howto says that the shorter of the two wins */ | |
710 | iov_iter_truncate(&iter, buf_len); | |
711 | if (check_iter_count && !iov_iter_count(&iter)) { | |
712 | kfree(iov); | |
713 | return -EINVAL; | |
714 | } | |
715 | } | |
716 | ||
717 | ret = blk_rq_map_user_iov(req->q, req, map_data, &iter, | |
718 | gfp_mask); | |
719 | kfree(iov); | |
720 | } else if (buf_len) { | |
721 | ret = blk_rq_map_user(req->q, req, map_data, ubuf, buf_len, | |
722 | gfp_mask); | |
723 | } | |
724 | return ret; | |
725 | } | |
726 | EXPORT_SYMBOL(blk_rq_map_user_io); | |
727 | ||
86db1e29 JA |
728 | /** |
729 | * blk_rq_unmap_user - unmap a request with user data | |
730 | * @bio: start of bio list | |
731 | * | |
732 | * Description: | |
733 | * Unmap a rq previously mapped by blk_rq_map_user(). The caller must | |
734 | * supply the original rq->bio from the blk_rq_map_user() return, since | |
710027a4 | 735 | * the I/O completion may have changed rq->bio. |
86db1e29 JA |
736 | */ |
737 | int blk_rq_unmap_user(struct bio *bio) | |
738 | { | |
393bb12e | 739 | struct bio *next_bio; |
86db1e29 JA |
740 | int ret = 0, ret2; |
741 | ||
742 | while (bio) { | |
3310eeba | 743 | if (bio->bi_private) { |
393bb12e | 744 | ret2 = bio_uncopy_user(bio); |
7b63c052 CH |
745 | if (ret2 && !ret) |
746 | ret = ret2; | |
3310eeba | 747 | } else { |
393bb12e | 748 | bio_release_pages(bio, bio_data_dir(bio) == READ); |
7b63c052 | 749 | } |
86db1e29 | 750 | |
393bb12e | 751 | next_bio = bio; |
86db1e29 | 752 | bio = bio->bi_next; |
32f1c71b | 753 | blk_mq_map_bio_put(next_bio); |
86db1e29 JA |
754 | } |
755 | ||
756 | return ret; | |
757 | } | |
86db1e29 JA |
758 | EXPORT_SYMBOL(blk_rq_unmap_user); |
759 | ||
760 | /** | |
aebf526b | 761 | * blk_rq_map_kern - map kernel data to a request, for passthrough requests |
86db1e29 JA |
762 | * @q: request queue where request should be inserted |
763 | * @rq: request to fill | |
764 | * @kbuf: the kernel buffer | |
765 | * @len: length of user data | |
766 | * @gfp_mask: memory allocation flags | |
68154e90 FT |
767 | * |
768 | * Description: | |
769 | * Data will be mapped directly if possible. Otherwise a bounce | |
e227867f | 770 | * buffer is used. Can be called multiple times to append multiple |
3a5a3927 | 771 | * buffers. |
86db1e29 JA |
772 | */ |
773 | int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, | |
774 | unsigned int len, gfp_t gfp_mask) | |
775 | { | |
68154e90 | 776 | int reading = rq_data_dir(rq) == READ; |
14417799 | 777 | unsigned long addr = (unsigned long) kbuf; |
393bb12e | 778 | struct bio *bio; |
3a5a3927 | 779 | int ret; |
86db1e29 | 780 | |
ae03bf63 | 781 | if (len > (queue_max_hw_sectors(q) << 9)) |
86db1e29 JA |
782 | return -EINVAL; |
783 | if (!len || !kbuf) | |
784 | return -EINVAL; | |
785 | ||
393bb12e CH |
786 | if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) || |
787 | blk_queue_may_bounce(q)) | |
68154e90 FT |
788 | bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading); |
789 | else | |
790 | bio = bio_map_kern(q, kbuf, len, gfp_mask); | |
791 | ||
86db1e29 JA |
792 | if (IS_ERR(bio)) |
793 | return PTR_ERR(bio); | |
794 | ||
aebf526b CH |
795 | bio->bi_opf &= ~REQ_OP_MASK; |
796 | bio->bi_opf |= req_op(rq); | |
86db1e29 | 797 | |
393bb12e | 798 | ret = blk_rq_append_bio(rq, bio); |
066ff571 CH |
799 | if (unlikely(ret)) { |
800 | bio_uninit(bio); | |
801 | kfree(bio); | |
802 | } | |
393bb12e | 803 | return ret; |
86db1e29 | 804 | } |
86db1e29 | 805 | EXPORT_SYMBOL(blk_rq_map_kern); |