Line data Source code
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 0 : 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 0 : if (data->nr_segs > UIO_MAXIOV)
27 : return NULL;
28 :
29 0 : bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
30 0 : if (!bmd)
31 : return NULL;
32 0 : memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
33 0 : bmd->iter = *data;
34 0 : if (iter_is_iovec(data))
35 0 : bmd->iter.iov = bmd->iov;
36 : return bmd;
37 : }
38 :
39 : /**
40 : * bio_copy_from_iter - copy all pages from iov_iter to bio
41 : * @bio: The &struct bio which describes the I/O as destination
42 : * @iter: iov_iter as source
43 : *
44 : * Copy all pages from iov_iter to bio.
45 : * Returns 0 on success, or error on failure.
46 : */
47 0 : static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
48 : {
49 : struct bio_vec *bvec;
50 : struct bvec_iter_all iter_all;
51 :
52 0 : bio_for_each_segment_all(bvec, bio, iter_all) {
53 : ssize_t ret;
54 :
55 0 : ret = copy_page_from_iter(bvec->bv_page,
56 0 : bvec->bv_offset,
57 0 : bvec->bv_len,
58 : iter);
59 :
60 0 : if (!iov_iter_count(iter))
61 : break;
62 :
63 0 : if (ret < bvec->bv_len)
64 : return -EFAULT;
65 : }
66 :
67 : return 0;
68 : }
69 :
70 : /**
71 : * bio_copy_to_iter - copy all pages from bio to iov_iter
72 : * @bio: The &struct bio which describes the I/O as source
73 : * @iter: iov_iter as destination
74 : *
75 : * Copy all pages from bio to iov_iter.
76 : * Returns 0 on success, or error on failure.
77 : */
78 0 : static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
79 : {
80 : struct bio_vec *bvec;
81 : struct bvec_iter_all iter_all;
82 :
83 0 : bio_for_each_segment_all(bvec, bio, iter_all) {
84 : ssize_t ret;
85 :
86 0 : ret = copy_page_to_iter(bvec->bv_page,
87 0 : bvec->bv_offset,
88 0 : bvec->bv_len,
89 : &iter);
90 :
91 0 : if (!iov_iter_count(&iter))
92 : break;
93 :
94 0 : if (ret < bvec->bv_len)
95 : return -EFAULT;
96 : }
97 :
98 : return 0;
99 : }
100 :
101 : /**
102 : * bio_uncopy_user - finish previously mapped bio
103 : * @bio: bio being terminated
104 : *
105 : * Free pages allocated from bio_copy_user_iov() and write back data
106 : * to user space in case of a read.
107 : */
108 0 : static int bio_uncopy_user(struct bio *bio)
109 : {
110 0 : struct bio_map_data *bmd = bio->bi_private;
111 0 : int ret = 0;
112 :
113 0 : if (!bmd->is_null_mapped) {
114 : /*
115 : * if we're in a workqueue, the request is orphaned, so
116 : * don't copy into a random user address space, just free
117 : * and return -EINTR so user space doesn't expect any data.
118 : */
119 0 : if (!current->mm)
120 : ret = -EINTR;
121 0 : else if (bio_data_dir(bio) == READ)
122 0 : ret = bio_copy_to_iter(bio, bmd->iter);
123 0 : if (bmd->is_our_pages)
124 0 : bio_free_pages(bio);
125 : }
126 0 : kfree(bmd);
127 0 : return ret;
128 : }
129 :
130 0 : static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
131 : struct iov_iter *iter, gfp_t gfp_mask)
132 : {
133 : struct bio_map_data *bmd;
134 : struct page *page;
135 : struct bio *bio;
136 0 : int i = 0, ret;
137 : int nr_pages;
138 0 : unsigned int len = iter->count;
139 0 : unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
140 :
141 0 : bmd = bio_alloc_map_data(iter, gfp_mask);
142 0 : if (!bmd)
143 : return -ENOMEM;
144 :
145 : /*
146 : * We need to do a deep copy of the iov_iter including the iovecs.
147 : * The caller provided iov might point to an on-stack or otherwise
148 : * shortlived one.
149 : */
150 0 : bmd->is_our_pages = !map_data;
151 0 : bmd->is_null_mapped = (map_data && map_data->null_mapped);
152 :
153 0 : nr_pages = bio_max_segs(DIV_ROUND_UP(offset + len, PAGE_SIZE));
154 :
155 0 : ret = -ENOMEM;
156 0 : bio = bio_kmalloc(nr_pages, gfp_mask);
157 0 : if (!bio)
158 : goto out_bmd;
159 0 : bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, req_op(rq));
160 :
161 0 : if (map_data) {
162 0 : nr_pages = 1U << map_data->page_order;
163 0 : i = map_data->offset / PAGE_SIZE;
164 : }
165 0 : while (len) {
166 0 : unsigned int bytes = PAGE_SIZE;
167 :
168 0 : bytes -= offset;
169 :
170 0 : if (bytes > len)
171 0 : bytes = len;
172 :
173 0 : if (map_data) {
174 0 : if (i == map_data->nr_entries * nr_pages) {
175 : ret = -ENOMEM;
176 : goto cleanup;
177 : }
178 :
179 0 : page = map_data->pages[i / nr_pages];
180 0 : page += (i % nr_pages);
181 :
182 0 : i++;
183 : } else {
184 0 : page = alloc_page(GFP_NOIO | gfp_mask);
185 0 : if (!page) {
186 : ret = -ENOMEM;
187 : goto cleanup;
188 : }
189 : }
190 :
191 0 : if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) {
192 0 : if (!map_data)
193 0 : __free_page(page);
194 : break;
195 : }
196 :
197 0 : len -= bytes;
198 0 : offset = 0;
199 : }
200 :
201 0 : if (map_data)
202 0 : map_data->offset += bio->bi_iter.bi_size;
203 :
204 : /*
205 : * success
206 : */
207 0 : if ((iov_iter_rw(iter) == WRITE &&
208 0 : (!map_data || !map_data->null_mapped)) ||
209 0 : (map_data && map_data->from_user)) {
210 0 : ret = bio_copy_from_iter(bio, iter);
211 0 : if (ret)
212 : goto cleanup;
213 : } else {
214 0 : if (bmd->is_our_pages)
215 0 : zero_fill_bio(bio);
216 0 : iov_iter_advance(iter, bio->bi_iter.bi_size);
217 : }
218 :
219 0 : bio->bi_private = bmd;
220 :
221 0 : ret = blk_rq_append_bio(rq, bio);
222 0 : if (ret)
223 : goto cleanup;
224 : return 0;
225 : cleanup:
226 0 : if (!map_data)
227 0 : bio_free_pages(bio);
228 0 : bio_uninit(bio);
229 0 : kfree(bio);
230 : out_bmd:
231 0 : kfree(bmd);
232 0 : return ret;
233 : }
234 :
235 0 : static void blk_mq_map_bio_put(struct bio *bio)
236 : {
237 0 : if (bio->bi_opf & REQ_ALLOC_CACHE) {
238 0 : bio_put(bio);
239 : } else {
240 0 : bio_uninit(bio);
241 0 : kfree(bio);
242 : }
243 0 : }
244 :
245 0 : static struct bio *blk_rq_map_bio_alloc(struct request *rq,
246 : unsigned int nr_vecs, gfp_t gfp_mask)
247 : {
248 : struct bio *bio;
249 :
250 0 : if (rq->cmd_flags & REQ_ALLOC_CACHE) {
251 0 : bio = bio_alloc_bioset(NULL, nr_vecs, rq->cmd_flags, gfp_mask,
252 : &fs_bio_set);
253 0 : if (!bio)
254 : return NULL;
255 : } else {
256 0 : bio = bio_kmalloc(nr_vecs, gfp_mask);
257 0 : if (!bio)
258 : return NULL;
259 0 : bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq));
260 : }
261 : return bio;
262 : }
263 :
264 0 : static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
265 : gfp_t gfp_mask)
266 : {
267 0 : iov_iter_extraction_t extraction_flags = 0;
268 0 : unsigned int max_sectors = queue_max_hw_sectors(rq->q);
269 0 : unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
270 : struct bio *bio;
271 : int ret;
272 : int j;
273 :
274 0 : if (!iov_iter_count(iter))
275 : return -EINVAL;
276 :
277 0 : bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
278 0 : if (bio == NULL)
279 : return -ENOMEM;
280 :
281 0 : if (blk_queue_pci_p2pdma(rq->q))
282 0 : extraction_flags |= ITER_ALLOW_P2PDMA;
283 :
284 0 : while (iov_iter_count(iter)) {
285 : struct page **pages, *stack_pages[UIO_FASTIOV];
286 : ssize_t bytes;
287 : size_t offs;
288 : int npages;
289 :
290 0 : if (nr_vecs <= ARRAY_SIZE(stack_pages)) {
291 0 : pages = stack_pages;
292 0 : bytes = iov_iter_get_pages(iter, pages, LONG_MAX,
293 : nr_vecs, &offs, extraction_flags);
294 : } else {
295 0 : bytes = iov_iter_get_pages_alloc(iter, &pages,
296 : LONG_MAX, &offs, extraction_flags);
297 : }
298 0 : if (unlikely(bytes <= 0)) {
299 0 : ret = bytes ? bytes : -EFAULT;
300 0 : goto out_unmap;
301 : }
302 :
303 0 : npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
304 :
305 0 : if (unlikely(offs & queue_dma_alignment(rq->q)))
306 : j = 0;
307 : else {
308 0 : for (j = 0; j < npages; j++) {
309 0 : struct page *page = pages[j];
310 0 : unsigned int n = PAGE_SIZE - offs;
311 0 : bool same_page = false;
312 :
313 0 : if (n > bytes)
314 0 : n = bytes;
315 :
316 0 : if (!bio_add_hw_page(rq->q, bio, page, n, offs,
317 : max_sectors, &same_page)) {
318 0 : if (same_page)
319 0 : put_page(page);
320 0 : break;
321 : }
322 :
323 0 : bytes -= n;
324 0 : offs = 0;
325 : }
326 : }
327 : /*
328 : * release the pages we didn't map into the bio, if any
329 : */
330 0 : while (j < npages)
331 0 : put_page(pages[j++]);
332 0 : if (pages != stack_pages)
333 0 : kvfree(pages);
334 : /* couldn't stuff something into bio? */
335 0 : if (bytes) {
336 0 : iov_iter_revert(iter, bytes);
337 0 : break;
338 : }
339 : }
340 :
341 0 : ret = blk_rq_append_bio(rq, bio);
342 0 : if (ret)
343 : goto out_unmap;
344 : return 0;
345 :
346 : out_unmap:
347 0 : bio_release_pages(bio, false);
348 0 : blk_mq_map_bio_put(bio);
349 0 : return ret;
350 : }
351 :
352 : static void bio_invalidate_vmalloc_pages(struct bio *bio)
353 : {
354 : #ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE
355 : if (bio->bi_private && !op_is_write(bio_op(bio))) {
356 : unsigned long i, len = 0;
357 :
358 : for (i = 0; i < bio->bi_vcnt; i++)
359 : len += bio->bi_io_vec[i].bv_len;
360 : invalidate_kernel_vmap_range(bio->bi_private, len);
361 : }
362 : #endif
363 : }
364 :
365 0 : static void bio_map_kern_endio(struct bio *bio)
366 : {
367 0 : bio_invalidate_vmalloc_pages(bio);
368 0 : bio_uninit(bio);
369 0 : kfree(bio);
370 0 : }
371 :
372 : /**
373 : * bio_map_kern - map kernel address into bio
374 : * @q: the struct request_queue for the bio
375 : * @data: pointer to buffer to map
376 : * @len: length in bytes
377 : * @gfp_mask: allocation flags for bio allocation
378 : *
379 : * Map the kernel address into a bio suitable for io to a block
380 : * device. Returns an error pointer in case of error.
381 : */
382 0 : static struct bio *bio_map_kern(struct request_queue *q, void *data,
383 : unsigned int len, gfp_t gfp_mask)
384 : {
385 0 : unsigned long kaddr = (unsigned long)data;
386 0 : unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
387 0 : unsigned long start = kaddr >> PAGE_SHIFT;
388 0 : const int nr_pages = end - start;
389 0 : bool is_vmalloc = is_vmalloc_addr(data);
390 : struct page *page;
391 : int offset, i;
392 : struct bio *bio;
393 :
394 0 : bio = bio_kmalloc(nr_pages, gfp_mask);
395 0 : if (!bio)
396 : return ERR_PTR(-ENOMEM);
397 0 : bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0);
398 :
399 0 : if (is_vmalloc) {
400 0 : flush_kernel_vmap_range(data, len);
401 0 : bio->bi_private = data;
402 : }
403 :
404 0 : offset = offset_in_page(kaddr);
405 0 : for (i = 0; i < nr_pages; i++) {
406 0 : unsigned int bytes = PAGE_SIZE - offset;
407 :
408 0 : if (len <= 0)
409 : break;
410 :
411 0 : if (bytes > len)
412 0 : bytes = len;
413 :
414 0 : if (!is_vmalloc)
415 0 : page = virt_to_page(data);
416 : else
417 0 : page = vmalloc_to_page(data);
418 0 : if (bio_add_pc_page(q, bio, page, bytes,
419 : offset) < bytes) {
420 : /* we don't support partial mappings */
421 0 : bio_uninit(bio);
422 0 : kfree(bio);
423 0 : return ERR_PTR(-EINVAL);
424 : }
425 :
426 0 : data += bytes;
427 0 : len -= bytes;
428 0 : offset = 0;
429 : }
430 :
431 0 : bio->bi_end_io = bio_map_kern_endio;
432 0 : return bio;
433 : }
434 :
435 0 : static void bio_copy_kern_endio(struct bio *bio)
436 : {
437 0 : bio_free_pages(bio);
438 0 : bio_uninit(bio);
439 0 : kfree(bio);
440 0 : }
441 :
442 0 : static void bio_copy_kern_endio_read(struct bio *bio)
443 : {
444 0 : char *p = bio->bi_private;
445 : struct bio_vec *bvec;
446 : struct bvec_iter_all iter_all;
447 :
448 0 : bio_for_each_segment_all(bvec, bio, iter_all) {
449 0 : memcpy_from_bvec(p, bvec);
450 0 : p += bvec->bv_len;
451 : }
452 :
453 0 : bio_copy_kern_endio(bio);
454 0 : }
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 0 : static struct bio *bio_copy_kern(struct request_queue *q, void *data,
468 : unsigned int len, gfp_t gfp_mask, int reading)
469 : {
470 0 : unsigned long kaddr = (unsigned long)data;
471 0 : unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
472 0 : unsigned long start = kaddr >> PAGE_SHIFT;
473 : struct bio *bio;
474 0 : void *p = data;
475 0 : int nr_pages = 0;
476 :
477 : /*
478 : * Overflow, abort
479 : */
480 0 : if (end < start)
481 : return ERR_PTR(-EINVAL);
482 :
483 0 : nr_pages = end - start;
484 0 : bio = bio_kmalloc(nr_pages, gfp_mask);
485 0 : if (!bio)
486 : return ERR_PTR(-ENOMEM);
487 0 : bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0);
488 :
489 0 : while (len) {
490 : struct page *page;
491 0 : unsigned int bytes = PAGE_SIZE;
492 :
493 0 : if (bytes > len)
494 0 : bytes = len;
495 :
496 0 : page = alloc_page(GFP_NOIO | __GFP_ZERO | gfp_mask);
497 0 : if (!page)
498 : goto cleanup;
499 :
500 0 : if (!reading)
501 0 : memcpy(page_address(page), p, bytes);
502 :
503 0 : if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
504 : break;
505 :
506 0 : len -= bytes;
507 0 : p += bytes;
508 : }
509 :
510 0 : if (reading) {
511 0 : bio->bi_end_io = bio_copy_kern_endio_read;
512 0 : bio->bi_private = data;
513 : } else {
514 0 : bio->bi_end_io = bio_copy_kern_endio;
515 : }
516 :
517 : return bio;
518 :
519 : cleanup:
520 0 : bio_free_pages(bio);
521 0 : bio_uninit(bio);
522 0 : kfree(bio);
523 0 : return ERR_PTR(-ENOMEM);
524 : }
525 :
526 : /*
527 : * Append a bio to a passthrough request. Only works if the bio can be merged
528 : * into the request based on the driver constraints.
529 : */
530 0 : int blk_rq_append_bio(struct request *rq, struct bio *bio)
531 : {
532 : struct bvec_iter iter;
533 : struct bio_vec bv;
534 0 : unsigned int nr_segs = 0;
535 :
536 0 : bio_for_each_bvec(bv, bio, iter)
537 0 : nr_segs++;
538 :
539 0 : if (!rq->bio) {
540 : blk_rq_bio_prep(rq, bio, nr_segs);
541 : } else {
542 0 : if (!ll_back_merge_fn(rq, bio, nr_segs))
543 : return -EINVAL;
544 0 : rq->biotail->bi_next = bio;
545 0 : rq->biotail = bio;
546 0 : rq->__data_len += (bio)->bi_iter.bi_size;
547 0 : bio_crypt_free_ctx(bio);
548 : }
549 :
550 : return 0;
551 : }
552 : EXPORT_SYMBOL(blk_rq_append_bio);
553 :
554 : /* Prepare bio for passthrough IO given ITER_BVEC iter */
555 0 : static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
556 : {
557 0 : struct request_queue *q = rq->q;
558 0 : size_t nr_iter = iov_iter_count(iter);
559 0 : size_t nr_segs = iter->nr_segs;
560 0 : struct bio_vec *bvecs, *bvprvp = NULL;
561 0 : const struct queue_limits *lim = &q->limits;
562 0 : unsigned int nsegs = 0, bytes = 0;
563 : struct bio *bio;
564 : size_t i;
565 :
566 0 : if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q))
567 : return -EINVAL;
568 0 : if (nr_segs > queue_max_segments(q))
569 : return -EINVAL;
570 :
571 : /* no iovecs to alloc, as we already have a BVEC iterator */
572 0 : bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL);
573 0 : if (bio == NULL)
574 : return -ENOMEM;
575 :
576 0 : bio_iov_bvec_set(bio, (struct iov_iter *)iter);
577 0 : blk_rq_bio_prep(rq, bio, nr_segs);
578 :
579 : /* loop to perform a bunch of sanity checks */
580 0 : bvecs = (struct bio_vec *)iter->bvec;
581 0 : for (i = 0; i < nr_segs; i++) {
582 0 : struct bio_vec *bv = &bvecs[i];
583 :
584 : /*
585 : * If the queue doesn't support SG gaps and adding this
586 : * offset would create a gap, fallback to copy.
587 : */
588 0 : if (bvprvp && bvec_gap_to_prev(lim, bvprvp, bv->bv_offset)) {
589 0 : blk_mq_map_bio_put(bio);
590 0 : return -EREMOTEIO;
591 : }
592 : /* check full condition */
593 0 : if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len)
594 : goto put_bio;
595 0 : if (bytes + bv->bv_len > nr_iter)
596 : goto put_bio;
597 0 : if (bv->bv_offset + bv->bv_len > PAGE_SIZE)
598 : goto put_bio;
599 :
600 0 : nsegs++;
601 0 : bytes += bv->bv_len;
602 0 : bvprvp = bv;
603 : }
604 : return 0;
605 : put_bio:
606 0 : blk_mq_map_bio_put(bio);
607 0 : return -EINVAL;
608 : }
609 :
610 : /**
611 : * blk_rq_map_user_iov - map user data to a request, for passthrough requests
612 : * @q: request queue where request should be inserted
613 : * @rq: request to map data to
614 : * @map_data: pointer to the rq_map_data holding pages (if necessary)
615 : * @iter: iovec iterator
616 : * @gfp_mask: memory allocation flags
617 : *
618 : * Description:
619 : * Data will be mapped directly for zero copy I/O, if possible. Otherwise
620 : * a kernel bounce buffer is used.
621 : *
622 : * A matching blk_rq_unmap_user() must be issued at the end of I/O, while
623 : * still in process context.
624 : */
625 0 : int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
626 : struct rq_map_data *map_data,
627 : const struct iov_iter *iter, gfp_t gfp_mask)
628 : {
629 0 : bool copy = false, map_bvec = false;
630 0 : unsigned long align = q->dma_pad_mask | queue_dma_alignment(q);
631 0 : struct bio *bio = NULL;
632 : struct iov_iter i;
633 0 : int ret = -EINVAL;
634 :
635 0 : if (map_data)
636 : copy = true;
637 0 : else if (blk_queue_may_bounce(q))
638 : copy = true;
639 0 : else if (iov_iter_alignment(iter) & align)
640 : copy = true;
641 0 : else if (iov_iter_is_bvec(iter))
642 : map_bvec = true;
643 0 : else if (!user_backed_iter(iter))
644 : copy = true;
645 0 : else if (queue_virt_boundary(q))
646 0 : copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter);
647 :
648 0 : if (map_bvec) {
649 0 : ret = blk_rq_map_user_bvec(rq, iter);
650 0 : if (!ret)
651 : return 0;
652 0 : if (ret != -EREMOTEIO)
653 : goto fail;
654 : /* fall back to copying the data on limits mismatches */
655 : copy = true;
656 : }
657 :
658 0 : i = *iter;
659 : do {
660 0 : if (copy)
661 0 : ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask);
662 : else
663 0 : ret = bio_map_user_iov(rq, &i, gfp_mask);
664 0 : if (ret)
665 : goto unmap_rq;
666 0 : if (!bio)
667 0 : bio = rq->bio;
668 0 : } while (iov_iter_count(&i));
669 :
670 : return 0;
671 :
672 : unmap_rq:
673 0 : blk_rq_unmap_user(bio);
674 : fail:
675 0 : rq->bio = NULL;
676 0 : return ret;
677 : }
678 : EXPORT_SYMBOL(blk_rq_map_user_iov);
679 :
680 0 : int blk_rq_map_user(struct request_queue *q, struct request *rq,
681 : struct rq_map_data *map_data, void __user *ubuf,
682 : unsigned long len, gfp_t gfp_mask)
683 : {
684 : struct iov_iter i;
685 0 : int ret = import_ubuf(rq_data_dir(rq), ubuf, len, &i);
686 :
687 0 : if (unlikely(ret < 0))
688 : return ret;
689 :
690 0 : return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask);
691 : }
692 : EXPORT_SYMBOL(blk_rq_map_user);
693 :
694 0 : int blk_rq_map_user_io(struct request *req, struct rq_map_data *map_data,
695 : void __user *ubuf, unsigned long buf_len, gfp_t gfp_mask,
696 : bool vec, int iov_count, bool check_iter_count, int rw)
697 : {
698 0 : int ret = 0;
699 :
700 0 : if (vec) {
701 : struct iovec fast_iov[UIO_FASTIOV];
702 0 : struct iovec *iov = fast_iov;
703 : struct iov_iter iter;
704 :
705 0 : ret = import_iovec(rw, ubuf, iov_count ? iov_count : buf_len,
706 : UIO_FASTIOV, &iov, &iter);
707 0 : if (ret < 0)
708 0 : return ret;
709 :
710 0 : if (iov_count) {
711 : /* SG_IO howto says that the shorter of the two wins */
712 0 : iov_iter_truncate(&iter, buf_len);
713 0 : if (check_iter_count && !iov_iter_count(&iter)) {
714 0 : kfree(iov);
715 0 : return -EINVAL;
716 : }
717 : }
718 :
719 0 : ret = blk_rq_map_user_iov(req->q, req, map_data, &iter,
720 : gfp_mask);
721 0 : kfree(iov);
722 0 : } else if (buf_len) {
723 0 : ret = blk_rq_map_user(req->q, req, map_data, ubuf, buf_len,
724 : gfp_mask);
725 : }
726 : return ret;
727 : }
728 : EXPORT_SYMBOL(blk_rq_map_user_io);
729 :
730 : /**
731 : * blk_rq_unmap_user - unmap a request with user data
732 : * @bio: start of bio list
733 : *
734 : * Description:
735 : * Unmap a rq previously mapped by blk_rq_map_user(). The caller must
736 : * supply the original rq->bio from the blk_rq_map_user() return, since
737 : * the I/O completion may have changed rq->bio.
738 : */
739 0 : int blk_rq_unmap_user(struct bio *bio)
740 : {
741 : struct bio *next_bio;
742 0 : int ret = 0, ret2;
743 :
744 0 : while (bio) {
745 0 : if (bio->bi_private) {
746 0 : ret2 = bio_uncopy_user(bio);
747 0 : if (ret2 && !ret)
748 0 : ret = ret2;
749 : } else {
750 0 : bio_release_pages(bio, bio_data_dir(bio) == READ);
751 : }
752 :
753 0 : next_bio = bio;
754 0 : bio = bio->bi_next;
755 0 : blk_mq_map_bio_put(next_bio);
756 : }
757 :
758 0 : return ret;
759 : }
760 : EXPORT_SYMBOL(blk_rq_unmap_user);
761 :
762 : /**
763 : * blk_rq_map_kern - map kernel data to a request, for passthrough requests
764 : * @q: request queue where request should be inserted
765 : * @rq: request to fill
766 : * @kbuf: the kernel buffer
767 : * @len: length of user data
768 : * @gfp_mask: memory allocation flags
769 : *
770 : * Description:
771 : * Data will be mapped directly if possible. Otherwise a bounce
772 : * buffer is used. Can be called multiple times to append multiple
773 : * buffers.
774 : */
775 0 : int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
776 : unsigned int len, gfp_t gfp_mask)
777 : {
778 0 : int reading = rq_data_dir(rq) == READ;
779 0 : unsigned long addr = (unsigned long) kbuf;
780 : struct bio *bio;
781 : int ret;
782 :
783 0 : if (len > (queue_max_hw_sectors(q) << 9))
784 : return -EINVAL;
785 0 : if (!len || !kbuf)
786 : return -EINVAL;
787 :
788 0 : if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) ||
789 0 : blk_queue_may_bounce(q))
790 0 : bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
791 : else
792 0 : bio = bio_map_kern(q, kbuf, len, gfp_mask);
793 :
794 0 : if (IS_ERR(bio))
795 0 : return PTR_ERR(bio);
796 :
797 0 : bio->bi_opf &= ~REQ_OP_MASK;
798 0 : bio->bi_opf |= req_op(rq);
799 :
800 0 : ret = blk_rq_append_bio(rq, bio);
801 0 : if (unlikely(ret)) {
802 0 : bio_uninit(bio);
803 0 : kfree(bio);
804 : }
805 : return ret;
806 : }
807 : EXPORT_SYMBOL(blk_rq_map_kern);
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