1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Functions related to mapping data to requests |
4 | */ |
5 | #include <linux/kernel.h> |
6 | #include <linux/sched/task_stack.h> |
7 | #include <linux/module.h> |
8 | #include <linux/bio.h> |
9 | #include <linux/blkdev.h> |
10 | #include <linux/uio.h> |
11 | |
12 | #include "blk.h" |
13 | |
14 | struct bio_map_data { |
15 | bool is_our_pages : 1; |
16 | bool is_null_mapped : 1; |
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), flags: gfp_mask); |
30 | if (!bmd) |
31 | return NULL; |
32 | bmd->iter = *data; |
33 | if (iter_is_iovec(i: data)) { |
34 | memcpy(bmd->iov, iter_iov(data), sizeof(struct iovec) * data->nr_segs); |
35 | bmd->iter.__iov = bmd->iov; |
36 | } |
37 | return bmd; |
38 | } |
39 | |
40 | /** |
41 | * bio_copy_from_iter - copy all pages from iov_iter to bio |
42 | * @bio: The &struct bio which describes the I/O as destination |
43 | * @iter: iov_iter as source |
44 | * |
45 | * Copy all pages from iov_iter to bio. |
46 | * Returns 0 on success, or error on failure. |
47 | */ |
48 | static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter) |
49 | { |
50 | struct bio_vec *bvec; |
51 | struct bvec_iter_all iter_all; |
52 | |
53 | bio_for_each_segment_all(bvec, bio, iter_all) { |
54 | ssize_t ret; |
55 | |
56 | ret = copy_page_from_iter(page: bvec->bv_page, |
57 | offset: bvec->bv_offset, |
58 | bytes: bvec->bv_len, |
59 | i: iter); |
60 | |
61 | if (!iov_iter_count(i: iter)) |
62 | break; |
63 | |
64 | if (ret < bvec->bv_len) |
65 | return -EFAULT; |
66 | } |
67 | |
68 | return 0; |
69 | } |
70 | |
71 | /** |
72 | * bio_copy_to_iter - copy all pages from bio to iov_iter |
73 | * @bio: The &struct bio which describes the I/O as source |
74 | * @iter: iov_iter as destination |
75 | * |
76 | * Copy all pages from bio to iov_iter. |
77 | * Returns 0 on success, or error on failure. |
78 | */ |
79 | static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter) |
80 | { |
81 | struct bio_vec *bvec; |
82 | struct bvec_iter_all iter_all; |
83 | |
84 | bio_for_each_segment_all(bvec, bio, iter_all) { |
85 | ssize_t ret; |
86 | |
87 | ret = copy_page_to_iter(page: bvec->bv_page, |
88 | offset: bvec->bv_offset, |
89 | bytes: bvec->bv_len, |
90 | i: &iter); |
91 | |
92 | if (!iov_iter_count(i: &iter)) |
93 | break; |
94 | |
95 | if (ret < bvec->bv_len) |
96 | return -EFAULT; |
97 | } |
98 | |
99 | return 0; |
100 | } |
101 | |
102 | /** |
103 | * bio_uncopy_user - finish previously mapped bio |
104 | * @bio: bio being terminated |
105 | * |
106 | * Free pages allocated from bio_copy_user_iov() and write back data |
107 | * to user space in case of a read. |
108 | */ |
109 | static int bio_uncopy_user(struct bio *bio) |
110 | { |
111 | struct bio_map_data *bmd = bio->bi_private; |
112 | int ret = 0; |
113 | |
114 | if (!bmd->is_null_mapped) { |
115 | /* |
116 | * if we're in a workqueue, the request is orphaned, so |
117 | * don't copy into a random user address space, just free |
118 | * and return -EINTR so user space doesn't expect any data. |
119 | */ |
120 | if (!current->mm) |
121 | ret = -EINTR; |
122 | else if (bio_data_dir(bio) == READ) |
123 | ret = bio_copy_to_iter(bio, iter: bmd->iter); |
124 | if (bmd->is_our_pages) |
125 | bio_free_pages(bio); |
126 | } |
127 | kfree(objp: bmd); |
128 | return ret; |
129 | } |
130 | |
131 | static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, |
132 | struct iov_iter *iter, gfp_t gfp_mask) |
133 | { |
134 | struct bio_map_data *bmd; |
135 | struct page *page; |
136 | struct bio *bio; |
137 | int i = 0, ret; |
138 | int nr_pages; |
139 | unsigned int len = iter->count; |
140 | unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; |
141 | |
142 | bmd = bio_alloc_map_data(data: iter, gfp_mask); |
143 | if (!bmd) |
144 | return -ENOMEM; |
145 | |
146 | /* |
147 | * We need to do a deep copy of the iov_iter including the iovecs. |
148 | * The caller provided iov might point to an on-stack or otherwise |
149 | * shortlived one. |
150 | */ |
151 | bmd->is_our_pages = !map_data; |
152 | bmd->is_null_mapped = (map_data && map_data->null_mapped); |
153 | |
154 | nr_pages = bio_max_segs(DIV_ROUND_UP(offset + len, PAGE_SIZE)); |
155 | |
156 | ret = -ENOMEM; |
157 | bio = bio_kmalloc(nr_vecs: nr_pages, gfp_mask); |
158 | if (!bio) |
159 | goto out_bmd; |
160 | bio_init(bio, NULL, table: bio->bi_inline_vecs, max_vecs: nr_pages, opf: req_op(req: rq)); |
161 | |
162 | if (map_data) { |
163 | nr_pages = 1U << map_data->page_order; |
164 | i = map_data->offset / PAGE_SIZE; |
165 | } |
166 | while (len) { |
167 | unsigned int bytes = PAGE_SIZE; |
168 | |
169 | bytes -= offset; |
170 | |
171 | if (bytes > len) |
172 | bytes = len; |
173 | |
174 | if (map_data) { |
175 | if (i == map_data->nr_entries * nr_pages) { |
176 | ret = -ENOMEM; |
177 | goto cleanup; |
178 | } |
179 | |
180 | page = map_data->pages[i / nr_pages]; |
181 | page += (i % nr_pages); |
182 | |
183 | i++; |
184 | } else { |
185 | page = alloc_page(GFP_NOIO | gfp_mask); |
186 | if (!page) { |
187 | ret = -ENOMEM; |
188 | goto cleanup; |
189 | } |
190 | } |
191 | |
192 | if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) { |
193 | if (!map_data) |
194 | __free_page(page); |
195 | break; |
196 | } |
197 | |
198 | len -= bytes; |
199 | offset = 0; |
200 | } |
201 | |
202 | if (map_data) |
203 | map_data->offset += bio->bi_iter.bi_size; |
204 | |
205 | /* |
206 | * success |
207 | */ |
208 | if (iov_iter_rw(i: iter) == WRITE && |
209 | (!map_data || !map_data->null_mapped)) { |
210 | ret = bio_copy_from_iter(bio, iter); |
211 | if (ret) |
212 | goto cleanup; |
213 | } else if (map_data && map_data->from_user) { |
214 | struct iov_iter iter2 = *iter; |
215 | |
216 | /* This is the copy-in part of SG_DXFER_TO_FROM_DEV. */ |
217 | iter2.data_source = ITER_SOURCE; |
218 | ret = bio_copy_from_iter(bio, iter: &iter2); |
219 | if (ret) |
220 | goto cleanup; |
221 | } else { |
222 | if (bmd->is_our_pages) |
223 | zero_fill_bio(bio); |
224 | iov_iter_advance(i: iter, bytes: bio->bi_iter.bi_size); |
225 | } |
226 | |
227 | bio->bi_private = bmd; |
228 | |
229 | ret = blk_rq_append_bio(rq, bio); |
230 | if (ret) |
231 | goto cleanup; |
232 | return 0; |
233 | cleanup: |
234 | if (!map_data) |
235 | bio_free_pages(bio); |
236 | bio_uninit(bio); |
237 | kfree(objp: bio); |
238 | out_bmd: |
239 | kfree(objp: bmd); |
240 | return ret; |
241 | } |
242 | |
243 | static void blk_mq_map_bio_put(struct bio *bio) |
244 | { |
245 | if (bio->bi_opf & REQ_ALLOC_CACHE) { |
246 | bio_put(bio); |
247 | } else { |
248 | bio_uninit(bio); |
249 | kfree(objp: bio); |
250 | } |
251 | } |
252 | |
253 | static struct bio *blk_rq_map_bio_alloc(struct request *rq, |
254 | unsigned int nr_vecs, gfp_t gfp_mask) |
255 | { |
256 | struct bio *bio; |
257 | |
258 | if (rq->cmd_flags & REQ_ALLOC_CACHE && (nr_vecs <= BIO_INLINE_VECS)) { |
259 | bio = bio_alloc_bioset(NULL, nr_vecs, opf: rq->cmd_flags, gfp_mask, |
260 | bs: &fs_bio_set); |
261 | if (!bio) |
262 | return NULL; |
263 | } else { |
264 | bio = bio_kmalloc(nr_vecs, gfp_mask); |
265 | if (!bio) |
266 | return NULL; |
267 | bio_init(bio, NULL, table: bio->bi_inline_vecs, max_vecs: nr_vecs, opf: req_op(req: rq)); |
268 | } |
269 | return bio; |
270 | } |
271 | |
272 | static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, |
273 | gfp_t gfp_mask) |
274 | { |
275 | iov_iter_extraction_t = 0; |
276 | unsigned int max_sectors = queue_max_hw_sectors(q: rq->q); |
277 | unsigned int nr_vecs = iov_iter_npages(i: iter, BIO_MAX_VECS); |
278 | struct bio *bio; |
279 | int ret; |
280 | int j; |
281 | |
282 | if (!iov_iter_count(i: iter)) |
283 | return -EINVAL; |
284 | |
285 | bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask); |
286 | if (bio == NULL) |
287 | return -ENOMEM; |
288 | |
289 | if (blk_queue_pci_p2pdma(rq->q)) |
290 | extraction_flags |= ITER_ALLOW_P2PDMA; |
291 | if (iov_iter_extract_will_pin(iter)) |
292 | bio_set_flag(bio, bit: BIO_PAGE_PINNED); |
293 | |
294 | while (iov_iter_count(i: iter)) { |
295 | struct page *stack_pages[UIO_FASTIOV]; |
296 | struct page **pages = stack_pages; |
297 | ssize_t bytes; |
298 | size_t offs; |
299 | int npages; |
300 | |
301 | if (nr_vecs > ARRAY_SIZE(stack_pages)) |
302 | pages = NULL; |
303 | |
304 | bytes = iov_iter_extract_pages(i: iter, pages: &pages, LONG_MAX, |
305 | maxpages: nr_vecs, extraction_flags, offset0: &offs); |
306 | if (unlikely(bytes <= 0)) { |
307 | ret = bytes ? bytes : -EFAULT; |
308 | goto out_unmap; |
309 | } |
310 | |
311 | npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); |
312 | |
313 | if (unlikely(offs & queue_dma_alignment(rq->q))) |
314 | j = 0; |
315 | else { |
316 | for (j = 0; j < npages; j++) { |
317 | struct page *page = pages[j]; |
318 | unsigned int n = PAGE_SIZE - offs; |
319 | bool same_page = false; |
320 | |
321 | if (n > bytes) |
322 | n = bytes; |
323 | |
324 | if (!bio_add_hw_page(q: rq->q, bio, page, len: n, offset: offs, |
325 | max_sectors, same_page: &same_page)) |
326 | break; |
327 | |
328 | if (same_page) |
329 | bio_release_page(bio, page); |
330 | bytes -= n; |
331 | offs = 0; |
332 | } |
333 | } |
334 | /* |
335 | * release the pages we didn't map into the bio, if any |
336 | */ |
337 | while (j < npages) |
338 | bio_release_page(bio, page: pages[j++]); |
339 | if (pages != stack_pages) |
340 | kvfree(addr: pages); |
341 | /* couldn't stuff something into bio? */ |
342 | if (bytes) { |
343 | iov_iter_revert(i: iter, bytes); |
344 | break; |
345 | } |
346 | } |
347 | |
348 | ret = blk_rq_append_bio(rq, bio); |
349 | if (ret) |
350 | goto out_unmap; |
351 | return 0; |
352 | |
353 | out_unmap: |
354 | bio_release_pages(bio, mark_dirty: false); |
355 | blk_mq_map_bio_put(bio); |
356 | return ret; |
357 | } |
358 | |
359 | static void bio_invalidate_vmalloc_pages(struct bio *bio) |
360 | { |
361 | #ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE |
362 | if (bio->bi_private && !op_is_write(bio_op(bio))) { |
363 | unsigned long i, len = 0; |
364 | |
365 | for (i = 0; i < bio->bi_vcnt; i++) |
366 | len += bio->bi_io_vec[i].bv_len; |
367 | invalidate_kernel_vmap_range(bio->bi_private, len); |
368 | } |
369 | #endif |
370 | } |
371 | |
372 | static void bio_map_kern_endio(struct bio *bio) |
373 | { |
374 | bio_invalidate_vmalloc_pages(bio); |
375 | bio_uninit(bio); |
376 | kfree(objp: bio); |
377 | } |
378 | |
379 | /** |
380 | * bio_map_kern - map kernel address into bio |
381 | * @q: the struct request_queue for the bio |
382 | * @data: pointer to buffer to map |
383 | * @len: length in bytes |
384 | * @gfp_mask: allocation flags for bio allocation |
385 | * |
386 | * Map the kernel address into a bio suitable for io to a block |
387 | * device. Returns an error pointer in case of error. |
388 | */ |
389 | static struct bio *bio_map_kern(struct request_queue *q, void *data, |
390 | unsigned int len, gfp_t gfp_mask) |
391 | { |
392 | unsigned long kaddr = (unsigned long)data; |
393 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
394 | unsigned long start = kaddr >> PAGE_SHIFT; |
395 | const int nr_pages = end - start; |
396 | bool is_vmalloc = is_vmalloc_addr(x: data); |
397 | struct page *page; |
398 | int offset, i; |
399 | struct bio *bio; |
400 | |
401 | bio = bio_kmalloc(nr_vecs: nr_pages, gfp_mask); |
402 | if (!bio) |
403 | return ERR_PTR(error: -ENOMEM); |
404 | bio_init(bio, NULL, table: bio->bi_inline_vecs, max_vecs: nr_pages, opf: 0); |
405 | |
406 | if (is_vmalloc) { |
407 | flush_kernel_vmap_range(vaddr: data, size: len); |
408 | bio->bi_private = data; |
409 | } |
410 | |
411 | offset = offset_in_page(kaddr); |
412 | for (i = 0; i < nr_pages; i++) { |
413 | unsigned int bytes = PAGE_SIZE - offset; |
414 | |
415 | if (len <= 0) |
416 | break; |
417 | |
418 | if (bytes > len) |
419 | bytes = len; |
420 | |
421 | if (!is_vmalloc) |
422 | page = virt_to_page(data); |
423 | else |
424 | page = vmalloc_to_page(addr: data); |
425 | if (bio_add_pc_page(q, bio, page, bytes, |
426 | offset) < bytes) { |
427 | /* we don't support partial mappings */ |
428 | bio_uninit(bio); |
429 | kfree(objp: bio); |
430 | return ERR_PTR(error: -EINVAL); |
431 | } |
432 | |
433 | data += bytes; |
434 | len -= bytes; |
435 | offset = 0; |
436 | } |
437 | |
438 | bio->bi_end_io = bio_map_kern_endio; |
439 | return bio; |
440 | } |
441 | |
442 | static void bio_copy_kern_endio(struct bio *bio) |
443 | { |
444 | bio_free_pages(bio); |
445 | bio_uninit(bio); |
446 | kfree(objp: bio); |
447 | } |
448 | |
449 | static void bio_copy_kern_endio_read(struct bio *bio) |
450 | { |
451 | char *p = bio->bi_private; |
452 | struct bio_vec *bvec; |
453 | struct bvec_iter_all iter_all; |
454 | |
455 | bio_for_each_segment_all(bvec, bio, iter_all) { |
456 | memcpy_from_bvec(to: p, bvec); |
457 | p += bvec->bv_len; |
458 | } |
459 | |
460 | bio_copy_kern_endio(bio); |
461 | } |
462 | |
463 | /** |
464 | * bio_copy_kern - copy kernel address into bio |
465 | * @q: the struct request_queue for the bio |
466 | * @data: pointer to buffer to copy |
467 | * @len: length in bytes |
468 | * @gfp_mask: allocation flags for bio and page allocation |
469 | * @reading: data direction is READ |
470 | * |
471 | * copy the kernel address into a bio suitable for io to a block |
472 | * device. Returns an error pointer in case of error. |
473 | */ |
474 | static struct bio *bio_copy_kern(struct request_queue *q, void *data, |
475 | unsigned int len, gfp_t gfp_mask, int reading) |
476 | { |
477 | unsigned long kaddr = (unsigned long)data; |
478 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
479 | unsigned long start = kaddr >> PAGE_SHIFT; |
480 | struct bio *bio; |
481 | void *p = data; |
482 | int nr_pages = 0; |
483 | |
484 | /* |
485 | * Overflow, abort |
486 | */ |
487 | if (end < start) |
488 | return ERR_PTR(error: -EINVAL); |
489 | |
490 | nr_pages = end - start; |
491 | bio = bio_kmalloc(nr_vecs: nr_pages, gfp_mask); |
492 | if (!bio) |
493 | return ERR_PTR(error: -ENOMEM); |
494 | bio_init(bio, NULL, table: bio->bi_inline_vecs, max_vecs: nr_pages, opf: 0); |
495 | |
496 | while (len) { |
497 | struct page *page; |
498 | unsigned int bytes = PAGE_SIZE; |
499 | |
500 | if (bytes > len) |
501 | bytes = len; |
502 | |
503 | page = alloc_page(GFP_NOIO | __GFP_ZERO | gfp_mask); |
504 | if (!page) |
505 | goto cleanup; |
506 | |
507 | if (!reading) |
508 | memcpy(page_address(page), p, bytes); |
509 | |
510 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) |
511 | break; |
512 | |
513 | len -= bytes; |
514 | p += bytes; |
515 | } |
516 | |
517 | if (reading) { |
518 | bio->bi_end_io = bio_copy_kern_endio_read; |
519 | bio->bi_private = data; |
520 | } else { |
521 | bio->bi_end_io = bio_copy_kern_endio; |
522 | } |
523 | |
524 | return bio; |
525 | |
526 | cleanup: |
527 | bio_free_pages(bio); |
528 | bio_uninit(bio); |
529 | kfree(objp: bio); |
530 | return ERR_PTR(error: -ENOMEM); |
531 | } |
532 | |
533 | /* |
534 | * Append a bio to a passthrough request. Only works if the bio can be merged |
535 | * into the request based on the driver constraints. |
536 | */ |
537 | int blk_rq_append_bio(struct request *rq, struct bio *bio) |
538 | { |
539 | struct bvec_iter iter; |
540 | struct bio_vec bv; |
541 | unsigned int nr_segs = 0; |
542 | |
543 | bio_for_each_bvec(bv, bio, iter) |
544 | nr_segs++; |
545 | |
546 | if (!rq->bio) { |
547 | blk_rq_bio_prep(rq, bio, nr_segs); |
548 | } else { |
549 | if (!ll_back_merge_fn(req: rq, bio, nr_segs)) |
550 | return -EINVAL; |
551 | rq->biotail->bi_next = bio; |
552 | rq->biotail = bio; |
553 | rq->__data_len += (bio)->bi_iter.bi_size; |
554 | bio_crypt_free_ctx(bio); |
555 | } |
556 | |
557 | return 0; |
558 | } |
559 | EXPORT_SYMBOL(blk_rq_append_bio); |
560 | |
561 | /* Prepare bio for passthrough IO given ITER_BVEC iter */ |
562 | static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter) |
563 | { |
564 | struct request_queue *q = rq->q; |
565 | size_t nr_iter = iov_iter_count(i: iter); |
566 | size_t nr_segs = iter->nr_segs; |
567 | struct bio_vec *bvecs, *bvprvp = NULL; |
568 | const struct queue_limits *lim = &q->limits; |
569 | unsigned int nsegs = 0, bytes = 0; |
570 | struct bio *bio; |
571 | size_t i; |
572 | |
573 | if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q)) |
574 | return -EINVAL; |
575 | if (nr_segs > queue_max_segments(q)) |
576 | return -EINVAL; |
577 | |
578 | /* no iovecs to alloc, as we already have a BVEC iterator */ |
579 | bio = blk_rq_map_bio_alloc(rq, nr_vecs: 0, GFP_KERNEL); |
580 | if (bio == NULL) |
581 | return -ENOMEM; |
582 | |
583 | bio_iov_bvec_set(bio, iter: (struct iov_iter *)iter); |
584 | blk_rq_bio_prep(rq, bio, nr_segs); |
585 | |
586 | /* loop to perform a bunch of sanity checks */ |
587 | bvecs = (struct bio_vec *)iter->bvec; |
588 | for (i = 0; i < nr_segs; i++) { |
589 | struct bio_vec *bv = &bvecs[i]; |
590 | |
591 | /* |
592 | * If the queue doesn't support SG gaps and adding this |
593 | * offset would create a gap, fallback to copy. |
594 | */ |
595 | if (bvprvp && bvec_gap_to_prev(lim, bprv: bvprvp, offset: bv->bv_offset)) { |
596 | blk_mq_map_bio_put(bio); |
597 | return -EREMOTEIO; |
598 | } |
599 | /* check full condition */ |
600 | if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len) |
601 | goto put_bio; |
602 | if (bytes + bv->bv_len > nr_iter) |
603 | goto put_bio; |
604 | if (bv->bv_offset + bv->bv_len > PAGE_SIZE) |
605 | goto put_bio; |
606 | |
607 | nsegs++; |
608 | bytes += bv->bv_len; |
609 | bvprvp = bv; |
610 | } |
611 | return 0; |
612 | put_bio: |
613 | blk_mq_map_bio_put(bio); |
614 | return -EINVAL; |
615 | } |
616 | |
617 | /** |
618 | * blk_rq_map_user_iov - map user data to a request, for passthrough requests |
619 | * @q: request queue where request should be inserted |
620 | * @rq: request to map data to |
621 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
622 | * @iter: iovec iterator |
623 | * @gfp_mask: memory allocation flags |
624 | * |
625 | * Description: |
626 | * Data will be mapped directly for zero copy I/O, if possible. Otherwise |
627 | * a kernel bounce buffer is used. |
628 | * |
629 | * A matching blk_rq_unmap_user() must be issued at the end of I/O, while |
630 | * still in process context. |
631 | */ |
632 | int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, |
633 | struct rq_map_data *map_data, |
634 | const struct iov_iter *iter, gfp_t gfp_mask) |
635 | { |
636 | bool copy = false, map_bvec = false; |
637 | unsigned long align = q->dma_pad_mask | queue_dma_alignment(q); |
638 | struct bio *bio = NULL; |
639 | struct iov_iter i; |
640 | int ret = -EINVAL; |
641 | |
642 | if (map_data) |
643 | copy = true; |
644 | else if (blk_queue_may_bounce(q)) |
645 | copy = true; |
646 | else if (iov_iter_alignment(i: iter) & align) |
647 | copy = true; |
648 | else if (iov_iter_is_bvec(i: iter)) |
649 | map_bvec = true; |
650 | else if (!user_backed_iter(i: iter)) |
651 | copy = true; |
652 | else if (queue_virt_boundary(q)) |
653 | copy = queue_virt_boundary(q) & iov_iter_gap_alignment(i: iter); |
654 | |
655 | if (map_bvec) { |
656 | ret = blk_rq_map_user_bvec(rq, iter); |
657 | if (!ret) |
658 | return 0; |
659 | if (ret != -EREMOTEIO) |
660 | goto fail; |
661 | /* fall back to copying the data on limits mismatches */ |
662 | copy = true; |
663 | } |
664 | |
665 | i = *iter; |
666 | do { |
667 | if (copy) |
668 | ret = bio_copy_user_iov(rq, map_data, iter: &i, gfp_mask); |
669 | else |
670 | ret = bio_map_user_iov(rq, iter: &i, gfp_mask); |
671 | if (ret) |
672 | goto unmap_rq; |
673 | if (!bio) |
674 | bio = rq->bio; |
675 | } while (iov_iter_count(i: &i)); |
676 | |
677 | return 0; |
678 | |
679 | unmap_rq: |
680 | blk_rq_unmap_user(bio); |
681 | fail: |
682 | rq->bio = NULL; |
683 | return ret; |
684 | } |
685 | EXPORT_SYMBOL(blk_rq_map_user_iov); |
686 | |
687 | int blk_rq_map_user(struct request_queue *q, struct request *rq, |
688 | struct rq_map_data *map_data, void __user *ubuf, |
689 | unsigned long len, gfp_t gfp_mask) |
690 | { |
691 | struct iov_iter i; |
692 | int ret = import_ubuf(rq_data_dir(rq), buf: ubuf, len, i: &i); |
693 | |
694 | if (unlikely(ret < 0)) |
695 | return ret; |
696 | |
697 | return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask); |
698 | } |
699 | EXPORT_SYMBOL(blk_rq_map_user); |
700 | |
701 | int blk_rq_map_user_io(struct request *req, struct rq_map_data *map_data, |
702 | void __user *ubuf, unsigned long buf_len, gfp_t gfp_mask, |
703 | bool vec, int iov_count, bool check_iter_count, int rw) |
704 | { |
705 | int ret = 0; |
706 | |
707 | if (vec) { |
708 | struct iovec fast_iov[UIO_FASTIOV]; |
709 | struct iovec *iov = fast_iov; |
710 | struct iov_iter iter; |
711 | |
712 | ret = import_iovec(type: rw, uvec: ubuf, nr_segs: iov_count ? iov_count : buf_len, |
713 | UIO_FASTIOV, iovp: &iov, i: &iter); |
714 | if (ret < 0) |
715 | return ret; |
716 | |
717 | if (iov_count) { |
718 | /* SG_IO howto says that the shorter of the two wins */ |
719 | iov_iter_truncate(i: &iter, count: buf_len); |
720 | if (check_iter_count && !iov_iter_count(i: &iter)) { |
721 | kfree(objp: iov); |
722 | return -EINVAL; |
723 | } |
724 | } |
725 | |
726 | ret = blk_rq_map_user_iov(req->q, req, map_data, &iter, |
727 | gfp_mask); |
728 | kfree(objp: iov); |
729 | } else if (buf_len) { |
730 | ret = blk_rq_map_user(req->q, req, map_data, ubuf, buf_len, |
731 | gfp_mask); |
732 | } |
733 | return ret; |
734 | } |
735 | EXPORT_SYMBOL(blk_rq_map_user_io); |
736 | |
737 | /** |
738 | * blk_rq_unmap_user - unmap a request with user data |
739 | * @bio: start of bio list |
740 | * |
741 | * Description: |
742 | * Unmap a rq previously mapped by blk_rq_map_user(). The caller must |
743 | * supply the original rq->bio from the blk_rq_map_user() return, since |
744 | * the I/O completion may have changed rq->bio. |
745 | */ |
746 | int blk_rq_unmap_user(struct bio *bio) |
747 | { |
748 | struct bio *next_bio; |
749 | int ret = 0, ret2; |
750 | |
751 | while (bio) { |
752 | if (bio->bi_private) { |
753 | ret2 = bio_uncopy_user(bio); |
754 | if (ret2 && !ret) |
755 | ret = ret2; |
756 | } else { |
757 | bio_release_pages(bio, bio_data_dir(bio) == READ); |
758 | } |
759 | |
760 | next_bio = bio; |
761 | bio = bio->bi_next; |
762 | blk_mq_map_bio_put(bio: next_bio); |
763 | } |
764 | |
765 | return ret; |
766 | } |
767 | EXPORT_SYMBOL(blk_rq_unmap_user); |
768 | |
769 | /** |
770 | * blk_rq_map_kern - map kernel data to a request, for passthrough requests |
771 | * @q: request queue where request should be inserted |
772 | * @rq: request to fill |
773 | * @kbuf: the kernel buffer |
774 | * @len: length of user data |
775 | * @gfp_mask: memory allocation flags |
776 | * |
777 | * Description: |
778 | * Data will be mapped directly if possible. Otherwise a bounce |
779 | * buffer is used. Can be called multiple times to append multiple |
780 | * buffers. |
781 | */ |
782 | int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf, |
783 | unsigned int len, gfp_t gfp_mask) |
784 | { |
785 | int reading = rq_data_dir(rq) == READ; |
786 | unsigned long addr = (unsigned long) kbuf; |
787 | struct bio *bio; |
788 | int ret; |
789 | |
790 | if (len > (queue_max_hw_sectors(q) << 9)) |
791 | return -EINVAL; |
792 | if (!len || !kbuf) |
793 | return -EINVAL; |
794 | |
795 | if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(obj: kbuf) || |
796 | blk_queue_may_bounce(q)) |
797 | bio = bio_copy_kern(q, data: kbuf, len, gfp_mask, reading); |
798 | else |
799 | bio = bio_map_kern(q, data: kbuf, len, gfp_mask); |
800 | |
801 | if (IS_ERR(ptr: bio)) |
802 | return PTR_ERR(ptr: bio); |
803 | |
804 | bio->bi_opf &= ~REQ_OP_MASK; |
805 | bio->bi_opf |= req_op(req: rq); |
806 | |
807 | ret = blk_rq_append_bio(rq, bio); |
808 | if (unlikely(ret)) { |
809 | bio_uninit(bio); |
810 | kfree(objp: bio); |
811 | } |
812 | return ret; |
813 | } |
814 | EXPORT_SYMBOL(blk_rq_map_kern); |
815 | |