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
bio_alloc_map_data(struct iov_iter * data,gfp_t gfp_mask)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 if (iter_is_iovec(data))
35 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 */
bio_copy_from_iter(struct bio * bio,struct iov_iter * iter)47 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 bio_for_each_segment_all(bvec, bio, iter_all) {
53 ssize_t ret;
54
55 ret = copy_page_from_iter(bvec->bv_page,
56 bvec->bv_offset,
57 bvec->bv_len,
58 iter);
59
60 if (!iov_iter_count(iter))
61 break;
62
63 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 */
bio_copy_to_iter(struct bio * bio,struct iov_iter iter)78 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 bio_for_each_segment_all(bvec, bio, iter_all) {
84 ssize_t ret;
85
86 ret = copy_page_to_iter(bvec->bv_page,
87 bvec->bv_offset,
88 bvec->bv_len,
89 &iter);
90
91 if (!iov_iter_count(&iter))
92 break;
93
94 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 */
bio_uncopy_user(struct bio * bio)108 static int bio_uncopy_user(struct bio *bio)
109 {
110 struct bio_map_data *bmd = bio->bi_private;
111 int ret = 0;
112
113 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 if (!current->mm)
120 ret = -EINTR;
121 else if (bio_data_dir(bio) == READ)
122 ret = bio_copy_to_iter(bio, bmd->iter);
123 if (bmd->is_our_pages)
124 bio_free_pages(bio);
125 }
126 kfree(bmd);
127 return ret;
128 }
129
bio_copy_user_iov(struct request * rq,struct rq_map_data * map_data,struct iov_iter * iter,gfp_t gfp_mask)130 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 int i = 0, ret;
137 int nr_pages;
138 unsigned int len = iter->count;
139 unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
140
141 bmd = bio_alloc_map_data(iter, gfp_mask);
142 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 bmd->is_our_pages = !map_data;
151 bmd->is_null_mapped = (map_data && map_data->null_mapped);
152
153 nr_pages = bio_max_segs(DIV_ROUND_UP(offset + len, PAGE_SIZE));
154
155 ret = -ENOMEM;
156 bio = bio_kmalloc(nr_pages, gfp_mask);
157 if (!bio)
158 goto out_bmd;
159 bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, req_op(rq));
160
161 if (map_data) {
162 nr_pages = 1U << map_data->page_order;
163 i = map_data->offset / PAGE_SIZE;
164 }
165 while (len) {
166 unsigned int bytes = PAGE_SIZE;
167
168 bytes -= offset;
169
170 if (bytes > len)
171 bytes = len;
172
173 if (map_data) {
174 if (i == map_data->nr_entries * nr_pages) {
175 ret = -ENOMEM;
176 goto cleanup;
177 }
178
179 page = map_data->pages[i / nr_pages];
180 page += (i % nr_pages);
181
182 i++;
183 } else {
184 page = alloc_page(GFP_NOIO | gfp_mask);
185 if (!page) {
186 ret = -ENOMEM;
187 goto cleanup;
188 }
189 }
190
191 if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) {
192 if (!map_data)
193 __free_page(page);
194 break;
195 }
196
197 len -= bytes;
198 offset = 0;
199 }
200
201 if (map_data)
202 map_data->offset += bio->bi_iter.bi_size;
203
204 /*
205 * success
206 */
207 if ((iov_iter_rw(iter) == WRITE &&
208 (!map_data || !map_data->null_mapped)) ||
209 (map_data && map_data->from_user)) {
210 ret = bio_copy_from_iter(bio, iter);
211 if (ret)
212 goto cleanup;
213 } else {
214 if (bmd->is_our_pages)
215 zero_fill_bio(bio);
216 iov_iter_advance(iter, bio->bi_iter.bi_size);
217 }
218
219 bio->bi_private = bmd;
220
221 ret = blk_rq_append_bio(rq, bio);
222 if (ret)
223 goto cleanup;
224 return 0;
225 cleanup:
226 if (!map_data)
227 bio_free_pages(bio);
228 bio_uninit(bio);
229 kfree(bio);
230 out_bmd:
231 kfree(bmd);
232 return ret;
233 }
234
blk_mq_map_bio_put(struct bio * bio)235 static void blk_mq_map_bio_put(struct bio *bio)
236 {
237 if (bio->bi_opf & REQ_ALLOC_CACHE) {
238 bio_put(bio);
239 } else {
240 bio_uninit(bio);
241 kfree(bio);
242 }
243 }
244
blk_rq_map_bio_alloc(struct request * rq,unsigned int nr_vecs,gfp_t gfp_mask)245 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 if (rq->cmd_flags & REQ_ALLOC_CACHE) {
251 bio = bio_alloc_bioset(NULL, nr_vecs, rq->cmd_flags, gfp_mask,
252 &fs_bio_set);
253 if (!bio)
254 return NULL;
255 } else {
256 bio = bio_kmalloc(nr_vecs, gfp_mask);
257 if (!bio)
258 return NULL;
259 bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq));
260 }
261 return bio;
262 }
263
bio_map_user_iov(struct request * rq,struct iov_iter * iter,gfp_t gfp_mask)264 static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
265 gfp_t gfp_mask)
266 {
267 iov_iter_extraction_t extraction_flags = 0;
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;
280
281 if (blk_queue_pci_p2pdma(rq->q))
282 extraction_flags |= ITER_ALLOW_P2PDMA;
283
284 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 if (nr_vecs <= ARRAY_SIZE(stack_pages)) {
291 pages = stack_pages;
292 bytes = iov_iter_get_pages(iter, pages, LONG_MAX,
293 nr_vecs, &offs, extraction_flags);
294 } else {
295 bytes = iov_iter_get_pages_alloc(iter, &pages,
296 LONG_MAX, &offs, extraction_flags);
297 }
298 if (unlikely(bytes <= 0)) {
299 ret = bytes ? bytes : -EFAULT;
300 goto out_unmap;
301 }
302
303 npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
304
305 if (unlikely(offs & queue_dma_alignment(rq->q)))
306 j = 0;
307 else {
308 for (j = 0; j < npages; j++) {
309 struct page *page = pages[j];
310 unsigned int n = PAGE_SIZE - offs;
311 bool same_page = false;
312
313 if (n > bytes)
314 n = bytes;
315
316 if (!bio_add_hw_page(rq->q, bio, page, n, offs,
317 max_sectors, &same_page)) {
318 if (same_page)
319 put_page(page);
320 break;
321 }
322
323 bytes -= n;
324 offs = 0;
325 }
326 }
327 /*
328 * release the pages we didn't map into the bio, if any
329 */
330 while (j < npages)
331 put_page(pages[j++]);
332 if (pages != stack_pages)
333 kvfree(pages);
334 /* couldn't stuff something into bio? */
335 if (bytes) {
336 iov_iter_revert(iter, bytes);
337 break;
338 }
339 }
340
341 ret = blk_rq_append_bio(rq, bio);
342 if (ret)
343 goto out_unmap;
344 return 0;
345
346 out_unmap:
347 bio_release_pages(bio, false);
348 blk_mq_map_bio_put(bio);
349 return ret;
350 }
351
bio_invalidate_vmalloc_pages(struct bio * bio)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
bio_map_kern_endio(struct bio * bio)365 static void bio_map_kern_endio(struct bio *bio)
366 {
367 bio_invalidate_vmalloc_pages(bio);
368 bio_uninit(bio);
369 kfree(bio);
370 }
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 */
bio_map_kern(struct request_queue * q,void * data,unsigned int len,gfp_t gfp_mask)382 static struct bio *bio_map_kern(struct request_queue *q, void *data,
383 unsigned int len, gfp_t gfp_mask)
384 {
385 unsigned long kaddr = (unsigned long)data;
386 unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
387 unsigned long start = kaddr >> PAGE_SHIFT;
388 const int nr_pages = end - start;
389 bool is_vmalloc = is_vmalloc_addr(data);
390 struct page *page;
391 int offset, i;
392 struct bio *bio;
393
394 bio = bio_kmalloc(nr_pages, gfp_mask);
395 if (!bio)
396 return ERR_PTR(-ENOMEM);
397 bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0);
398
399 if (is_vmalloc) {
400 flush_kernel_vmap_range(data, len);
401 bio->bi_private = data;
402 }
403
404 offset = offset_in_page(kaddr);
405 for (i = 0; i < nr_pages; i++) {
406 unsigned int bytes = PAGE_SIZE - offset;
407
408 if (len <= 0)
409 break;
410
411 if (bytes > len)
412 bytes = len;
413
414 if (!is_vmalloc)
415 page = virt_to_page(data);
416 else
417 page = vmalloc_to_page(data);
418 if (bio_add_pc_page(q, bio, page, bytes,
419 offset) < bytes) {
420 /* we don't support partial mappings */
421 bio_uninit(bio);
422 kfree(bio);
423 return ERR_PTR(-EINVAL);
424 }
425
426 data += bytes;
427 len -= bytes;
428 offset = 0;
429 }
430
431 bio->bi_end_io = bio_map_kern_endio;
432 return bio;
433 }
434
bio_copy_kern_endio(struct bio * bio)435 static void bio_copy_kern_endio(struct bio *bio)
436 {
437 bio_free_pages(bio);
438 bio_uninit(bio);
439 kfree(bio);
440 }
441
bio_copy_kern_endio_read(struct bio * bio)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_from_bvec(p, bvec);
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 */
bio_copy_kern(struct request_queue * q,void * data,unsigned int len,gfp_t gfp_mask,int reading)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(nr_pages, gfp_mask);
485 if (!bio)
486 return ERR_PTR(-ENOMEM);
487 bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0);
488
489 while (len) {
490 struct page *page;
491 unsigned int bytes = PAGE_SIZE;
492
493 if (bytes > len)
494 bytes = len;
495
496 page = alloc_page(GFP_NOIO | __GFP_ZERO | gfp_mask);
497 if (!page)
498 goto cleanup;
499
500 if (!reading)
501 memcpy(page_address(page), p, bytes);
502
503 if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
504 break;
505
506 len -= bytes;
507 p += bytes;
508 }
509
510 if (reading) {
511 bio->bi_end_io = bio_copy_kern_endio_read;
512 bio->bi_private = data;
513 } else {
514 bio->bi_end_io = bio_copy_kern_endio;
515 }
516
517 return bio;
518
519 cleanup:
520 bio_free_pages(bio);
521 bio_uninit(bio);
522 kfree(bio);
523 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 */
blk_rq_append_bio(struct request * rq,struct bio * bio)530 int blk_rq_append_bio(struct request *rq, struct bio *bio)
531 {
532 struct bvec_iter iter;
533 struct bio_vec bv;
534 unsigned int nr_segs = 0;
535
536 bio_for_each_bvec(bv, bio, iter)
537 nr_segs++;
538
539 if (!rq->bio) {
540 blk_rq_bio_prep(rq, bio, nr_segs);
541 } else {
542 if (!ll_back_merge_fn(rq, bio, nr_segs))
543 return -EINVAL;
544 rq->biotail->bi_next = bio;
545 rq->biotail = bio;
546 rq->__data_len += (bio)->bi_iter.bi_size;
547 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 */
blk_rq_map_user_bvec(struct request * rq,const struct iov_iter * iter)555 static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
556 {
557 struct request_queue *q = rq->q;
558 size_t nr_iter = iov_iter_count(iter);
559 size_t nr_segs = iter->nr_segs;
560 struct bio_vec *bvecs, *bvprvp = NULL;
561 const struct queue_limits *lim = &q->limits;
562 unsigned int nsegs = 0, bytes = 0;
563 struct bio *bio;
564 size_t i;
565
566 if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q))
567 return -EINVAL;
568 if (nr_segs > queue_max_segments(q))
569 return -EINVAL;
570
571 /* no iovecs to alloc, as we already have a BVEC iterator */
572 bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL);
573 if (bio == NULL)
574 return -ENOMEM;
575
576 bio_iov_bvec_set(bio, (struct iov_iter *)iter);
577 blk_rq_bio_prep(rq, bio, nr_segs);
578
579 /* loop to perform a bunch of sanity checks */
580 bvecs = (struct bio_vec *)iter->bvec;
581 for (i = 0; i < nr_segs; i++) {
582 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 if (bvprvp && bvec_gap_to_prev(lim, bvprvp, bv->bv_offset)) {
589 blk_mq_map_bio_put(bio);
590 return -EREMOTEIO;
591 }
592 /* check full condition */
593 if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len)
594 goto put_bio;
595 if (bytes + bv->bv_len > nr_iter)
596 goto put_bio;
597 if (bv->bv_offset + bv->bv_len > PAGE_SIZE)
598 goto put_bio;
599
600 nsegs++;
601 bytes += bv->bv_len;
602 bvprvp = bv;
603 }
604 return 0;
605 put_bio:
606 blk_mq_map_bio_put(bio);
607 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 */
blk_rq_map_user_iov(struct request_queue * q,struct request * rq,struct rq_map_data * map_data,const struct iov_iter * iter,gfp_t gfp_mask)625 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 bool copy = false, map_bvec = false;
630 unsigned long align = q->dma_pad_mask | queue_dma_alignment(q);
631 struct bio *bio = NULL;
632 struct iov_iter i;
633 int ret = -EINVAL;
634
635 if (map_data)
636 copy = true;
637 else if (blk_queue_may_bounce(q))
638 copy = true;
639 else if (iov_iter_alignment(iter) & align)
640 copy = true;
641 else if (iov_iter_is_bvec(iter))
642 map_bvec = true;
643 else if (!user_backed_iter(iter))
644 copy = true;
645 else if (queue_virt_boundary(q))
646 copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter);
647
648 if (map_bvec) {
649 ret = blk_rq_map_user_bvec(rq, iter);
650 if (!ret)
651 return 0;
652 if (ret != -EREMOTEIO)
653 goto fail;
654 /* fall back to copying the data on limits mismatches */
655 copy = true;
656 }
657
658 i = *iter;
659 do {
660 if (copy)
661 ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask);
662 else
663 ret = bio_map_user_iov(rq, &i, gfp_mask);
664 if (ret)
665 goto unmap_rq;
666 if (!bio)
667 bio = rq->bio;
668 } while (iov_iter_count(&i));
669
670 return 0;
671
672 unmap_rq:
673 blk_rq_unmap_user(bio);
674 fail:
675 rq->bio = NULL;
676 return ret;
677 }
678 EXPORT_SYMBOL(blk_rq_map_user_iov);
679
blk_rq_map_user(struct request_queue * q,struct request * rq,struct rq_map_data * map_data,void __user * ubuf,unsigned long len,gfp_t gfp_mask)680 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 int ret = import_ubuf(rq_data_dir(rq), ubuf, len, &i);
686
687 if (unlikely(ret < 0))
688 return ret;
689
690 return blk_rq_map_user_iov(q, rq, map_data, &i, gfp_mask);
691 }
692 EXPORT_SYMBOL(blk_rq_map_user);
693
blk_rq_map_user_io(struct request * req,struct rq_map_data * map_data,void __user * ubuf,unsigned long buf_len,gfp_t gfp_mask,bool vec,int iov_count,bool check_iter_count,int rw)694 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 int ret = 0;
699
700 if (vec) {
701 struct iovec fast_iov[UIO_FASTIOV];
702 struct iovec *iov = fast_iov;
703 struct iov_iter iter;
704
705 ret = import_iovec(rw, ubuf, iov_count ? iov_count : buf_len,
706 UIO_FASTIOV, &iov, &iter);
707 if (ret < 0)
708 return ret;
709
710 if (iov_count) {
711 /* SG_IO howto says that the shorter of the two wins */
712 iov_iter_truncate(&iter, buf_len);
713 if (check_iter_count && !iov_iter_count(&iter)) {
714 kfree(iov);
715 return -EINVAL;
716 }
717 }
718
719 ret = blk_rq_map_user_iov(req->q, req, map_data, &iter,
720 gfp_mask);
721 kfree(iov);
722 } else if (buf_len) {
723 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 */
blk_rq_unmap_user(struct bio * bio)739 int blk_rq_unmap_user(struct bio *bio)
740 {
741 struct bio *next_bio;
742 int ret = 0, ret2;
743
744 while (bio) {
745 if (bio->bi_private) {
746 ret2 = bio_uncopy_user(bio);
747 if (ret2 && !ret)
748 ret = ret2;
749 } else {
750 bio_release_pages(bio, bio_data_dir(bio) == READ);
751 }
752
753 next_bio = bio;
754 bio = bio->bi_next;
755 blk_mq_map_bio_put(next_bio);
756 }
757
758 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 */
blk_rq_map_kern(struct request_queue * q,struct request * rq,void * kbuf,unsigned int len,gfp_t gfp_mask)775 int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
776 unsigned int len, gfp_t gfp_mask)
777 {
778 int reading = rq_data_dir(rq) == READ;
779 unsigned long addr = (unsigned long) kbuf;
780 struct bio *bio;
781 int ret;
782
783 if (len > (queue_max_hw_sectors(q) << 9))
784 return -EINVAL;
785 if (!len || !kbuf)
786 return -EINVAL;
787
788 if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) ||
789 blk_queue_may_bounce(q))
790 bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
791 else
792 bio = bio_map_kern(q, kbuf, len, gfp_mask);
793
794 if (IS_ERR(bio))
795 return PTR_ERR(bio);
796
797 bio->bi_opf &= ~REQ_OP_MASK;
798 bio->bi_opf |= req_op(rq);
799
800 ret = blk_rq_append_bio(rq, bio);
801 if (unlikely(ret)) {
802 bio_uninit(bio);
803 kfree(bio);
804 }
805 return ret;
806 }
807 EXPORT_SYMBOL(blk_rq_map_kern);
808