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