1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * bio-integrity.c - bio data integrity extensions
4 *
5 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
6 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
7 */
8
9 #include <linux/blk-integrity.h>
10 #include "blk.h"
11
12 struct bio_integrity_alloc {
13 struct bio_integrity_payload bip;
14 struct bio_vec bvecs[];
15 };
16
17 /**
18 * bio_integrity_free - Free bio integrity payload
19 * @bio: bio containing bip to be freed
20 *
21 * Description: Free the integrity portion of a bio.
22 */
bio_integrity_free(struct bio * bio)23 void bio_integrity_free(struct bio *bio)
24 {
25 kfree(bio_integrity(bio));
26 bio->bi_integrity = NULL;
27 bio->bi_opf &= ~REQ_INTEGRITY;
28 }
29
bio_integrity_init(struct bio * bio,struct bio_integrity_payload * bip,struct bio_vec * bvecs,unsigned int nr_vecs)30 void bio_integrity_init(struct bio *bio, struct bio_integrity_payload *bip,
31 struct bio_vec *bvecs, unsigned int nr_vecs)
32 {
33 memset(bip, 0, sizeof(*bip));
34 bip->bip_max_vcnt = nr_vecs;
35 if (nr_vecs)
36 bip->bip_vec = bvecs;
37
38 bio->bi_integrity = bip;
39 bio->bi_opf |= REQ_INTEGRITY;
40 }
41
42 /**
43 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
44 * @bio: bio to attach integrity metadata to
45 * @gfp_mask: Memory allocation mask
46 * @nr_vecs: Number of integrity metadata scatter-gather elements
47 *
48 * Description: This function prepares a bio for attaching integrity
49 * metadata. nr_vecs specifies the maximum number of pages containing
50 * integrity metadata that can be attached.
51 */
bio_integrity_alloc(struct bio * bio,gfp_t gfp_mask,unsigned int nr_vecs)52 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
53 gfp_t gfp_mask,
54 unsigned int nr_vecs)
55 {
56 struct bio_integrity_alloc *bia;
57
58 if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
59 return ERR_PTR(-EOPNOTSUPP);
60
61 bia = kmalloc(struct_size(bia, bvecs, nr_vecs), gfp_mask);
62 if (unlikely(!bia))
63 return ERR_PTR(-ENOMEM);
64 bio_integrity_init(bio, &bia->bip, bia->bvecs, nr_vecs);
65 return &bia->bip;
66 }
67 EXPORT_SYMBOL(bio_integrity_alloc);
68
bio_integrity_unpin_bvec(struct bio_vec * bv,int nr_vecs)69 static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs)
70 {
71 int i;
72
73 for (i = 0; i < nr_vecs; i++)
74 unpin_user_page(bv[i].bv_page);
75 }
76
bio_integrity_uncopy_user(struct bio_integrity_payload * bip)77 static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
78 {
79 unsigned short orig_nr_vecs = bip->bip_max_vcnt - 1;
80 struct bio_vec *orig_bvecs = &bip->bip_vec[1];
81 struct bio_vec *bounce_bvec = &bip->bip_vec[0];
82 size_t bytes = bounce_bvec->bv_len;
83 struct iov_iter orig_iter;
84 int ret;
85
86 iov_iter_bvec(&orig_iter, ITER_DEST, orig_bvecs, orig_nr_vecs, bytes);
87 ret = copy_to_iter(bvec_virt(bounce_bvec), bytes, &orig_iter);
88 WARN_ON_ONCE(ret != bytes);
89
90 bio_integrity_unpin_bvec(orig_bvecs, orig_nr_vecs);
91 }
92
93 /**
94 * bio_integrity_unmap_user - Unmap user integrity payload
95 * @bio: bio containing bip to be unmapped
96 *
97 * Unmap the user mapped integrity portion of a bio.
98 */
bio_integrity_unmap_user(struct bio * bio)99 void bio_integrity_unmap_user(struct bio *bio)
100 {
101 struct bio_integrity_payload *bip = bio_integrity(bio);
102
103 if (bip->bip_flags & BIP_COPY_USER) {
104 if (bio_data_dir(bio) == READ)
105 bio_integrity_uncopy_user(bip);
106 kfree(bvec_virt(bip->bip_vec));
107 return;
108 }
109
110 bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt);
111 }
112
113 /**
114 * bio_integrity_add_page - Attach integrity metadata
115 * @bio: bio to update
116 * @page: page containing integrity metadata
117 * @len: number of bytes of integrity metadata in page
118 * @offset: start offset within page
119 *
120 * Description: Attach a page containing integrity metadata to bio.
121 */
bio_integrity_add_page(struct bio * bio,struct page * page,unsigned int len,unsigned int offset)122 int bio_integrity_add_page(struct bio *bio, struct page *page,
123 unsigned int len, unsigned int offset)
124 {
125 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
126 struct bio_integrity_payload *bip = bio_integrity(bio);
127
128 if (bip->bip_vcnt > 0) {
129 struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1];
130
131 if (bvec_try_merge_hw_page(q, bv, page, len, offset)) {
132 bip->bip_iter.bi_size += len;
133 return len;
134 }
135
136 if (bip->bip_vcnt >=
137 min(bip->bip_max_vcnt, queue_max_integrity_segments(q)))
138 return 0;
139
140 /*
141 * If the queue doesn't support SG gaps and adding this segment
142 * would create a gap, disallow it.
143 */
144 if (bvec_gap_to_prev(&q->limits, bv, offset))
145 return 0;
146 }
147
148 bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
149 bip->bip_vcnt++;
150 bip->bip_iter.bi_size += len;
151
152 return len;
153 }
154 EXPORT_SYMBOL(bio_integrity_add_page);
155
bio_integrity_copy_user(struct bio * bio,struct bio_vec * bvec,int nr_vecs,unsigned int len)156 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec,
157 int nr_vecs, unsigned int len)
158 {
159 bool write = op_is_write(bio_op(bio));
160 struct bio_integrity_payload *bip;
161 struct iov_iter iter;
162 void *buf;
163 int ret;
164
165 buf = kmalloc(len, GFP_KERNEL);
166 if (!buf)
167 return -ENOMEM;
168
169 if (write) {
170 iov_iter_bvec(&iter, ITER_SOURCE, bvec, nr_vecs, len);
171 if (!copy_from_iter_full(buf, len, &iter)) {
172 ret = -EFAULT;
173 goto free_buf;
174 }
175
176 bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
177 } else {
178 memset(buf, 0, len);
179
180 /*
181 * We need to preserve the original bvec and the number of vecs
182 * in it for completion handling
183 */
184 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1);
185 }
186
187 if (IS_ERR(bip)) {
188 ret = PTR_ERR(bip);
189 goto free_buf;
190 }
191
192 if (write)
193 bio_integrity_unpin_bvec(bvec, nr_vecs);
194 else
195 memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));
196
197 ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
198 offset_in_page(buf));
199 if (ret != len) {
200 ret = -ENOMEM;
201 goto free_bip;
202 }
203
204 bip->bip_flags |= BIP_COPY_USER;
205 bip->bip_vcnt = nr_vecs;
206 return 0;
207 free_bip:
208 bio_integrity_free(bio);
209 free_buf:
210 kfree(buf);
211 return ret;
212 }
213
bio_integrity_init_user(struct bio * bio,struct bio_vec * bvec,int nr_vecs,unsigned int len)214 static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec,
215 int nr_vecs, unsigned int len)
216 {
217 struct bio_integrity_payload *bip;
218
219 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs);
220 if (IS_ERR(bip))
221 return PTR_ERR(bip);
222
223 memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec));
224 bip->bip_iter.bi_size = len;
225 bip->bip_vcnt = nr_vecs;
226 return 0;
227 }
228
bvec_from_pages(struct bio_vec * bvec,struct page ** pages,int nr_vecs,ssize_t bytes,ssize_t offset)229 static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
230 int nr_vecs, ssize_t bytes, ssize_t offset)
231 {
232 unsigned int nr_bvecs = 0;
233 int i, j;
234
235 for (i = 0; i < nr_vecs; i = j) {
236 size_t size = min_t(size_t, bytes, PAGE_SIZE - offset);
237 struct folio *folio = page_folio(pages[i]);
238
239 bytes -= size;
240 for (j = i + 1; j < nr_vecs; j++) {
241 size_t next = min_t(size_t, PAGE_SIZE, bytes);
242
243 if (page_folio(pages[j]) != folio ||
244 pages[j] != pages[j - 1] + 1)
245 break;
246 unpin_user_page(pages[j]);
247 size += next;
248 bytes -= next;
249 }
250
251 bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset);
252 offset = 0;
253 nr_bvecs++;
254 }
255
256 return nr_bvecs;
257 }
258
bio_integrity_map_user(struct bio * bio,struct iov_iter * iter)259 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter)
260 {
261 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
262 unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits);
263 struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages;
264 struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
265 size_t offset, bytes = iter->count;
266 unsigned int nr_bvecs;
267 int ret, nr_vecs;
268 bool copy;
269
270 if (bio_integrity(bio))
271 return -EINVAL;
272 if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q))
273 return -E2BIG;
274
275 nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS + 1);
276 if (nr_vecs > BIO_MAX_VECS)
277 return -E2BIG;
278 if (nr_vecs > UIO_FASTIOV) {
279 bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL);
280 if (!bvec)
281 return -ENOMEM;
282 pages = NULL;
283 }
284
285 copy = !iov_iter_is_aligned(iter, align, align);
286 ret = iov_iter_extract_pages(iter, &pages, bytes, nr_vecs, 0, &offset);
287 if (unlikely(ret < 0))
288 goto free_bvec;
289
290 nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
291 if (pages != stack_pages)
292 kvfree(pages);
293 if (nr_bvecs > queue_max_integrity_segments(q))
294 copy = true;
295
296 if (copy)
297 ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes);
298 else
299 ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes);
300 if (ret)
301 goto release_pages;
302 if (bvec != stack_vec)
303 kfree(bvec);
304
305 return 0;
306
307 release_pages:
308 bio_integrity_unpin_bvec(bvec, nr_bvecs);
309 free_bvec:
310 if (bvec != stack_vec)
311 kfree(bvec);
312 return ret;
313 }
314
bio_uio_meta_to_bip(struct bio * bio,struct uio_meta * meta)315 static void bio_uio_meta_to_bip(struct bio *bio, struct uio_meta *meta)
316 {
317 struct bio_integrity_payload *bip = bio_integrity(bio);
318
319 if (meta->flags & IO_INTEGRITY_CHK_GUARD)
320 bip->bip_flags |= BIP_CHECK_GUARD;
321 if (meta->flags & IO_INTEGRITY_CHK_APPTAG)
322 bip->bip_flags |= BIP_CHECK_APPTAG;
323 if (meta->flags & IO_INTEGRITY_CHK_REFTAG)
324 bip->bip_flags |= BIP_CHECK_REFTAG;
325
326 bip->app_tag = meta->app_tag;
327 }
328
bio_integrity_map_iter(struct bio * bio,struct uio_meta * meta)329 int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta)
330 {
331 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
332 unsigned int integrity_bytes;
333 int ret;
334 struct iov_iter it;
335
336 if (!bi)
337 return -EINVAL;
338 /*
339 * original meta iterator can be bigger.
340 * process integrity info corresponding to current data buffer only.
341 */
342 it = meta->iter;
343 integrity_bytes = bio_integrity_bytes(bi, bio_sectors(bio));
344 if (it.count < integrity_bytes)
345 return -EINVAL;
346
347 /* should fit into two bytes */
348 BUILD_BUG_ON(IO_INTEGRITY_VALID_FLAGS >= (1 << 16));
349
350 if (meta->flags && (meta->flags & ~IO_INTEGRITY_VALID_FLAGS))
351 return -EINVAL;
352
353 it.count = integrity_bytes;
354 ret = bio_integrity_map_user(bio, &it);
355 if (!ret) {
356 bio_uio_meta_to_bip(bio, meta);
357 bip_set_seed(bio_integrity(bio), meta->seed);
358 iov_iter_advance(&meta->iter, integrity_bytes);
359 meta->seed += bio_integrity_intervals(bi, bio_sectors(bio));
360 }
361 return ret;
362 }
363
364 /**
365 * bio_integrity_advance - Advance integrity vector
366 * @bio: bio whose integrity vector to update
367 * @bytes_done: number of data bytes that have been completed
368 *
369 * Description: This function calculates how many integrity bytes the
370 * number of completed data bytes correspond to and advances the
371 * integrity vector accordingly.
372 */
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)373 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
374 {
375 struct bio_integrity_payload *bip = bio_integrity(bio);
376 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
377 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
378
379 bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
380 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
381 }
382
383 /**
384 * bio_integrity_trim - Trim integrity vector
385 * @bio: bio whose integrity vector to update
386 *
387 * Description: Used to trim the integrity vector in a cloned bio.
388 */
bio_integrity_trim(struct bio * bio)389 void bio_integrity_trim(struct bio *bio)
390 {
391 struct bio_integrity_payload *bip = bio_integrity(bio);
392 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
393
394 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
395 }
396 EXPORT_SYMBOL(bio_integrity_trim);
397
398 /**
399 * bio_integrity_clone - Callback for cloning bios with integrity metadata
400 * @bio: New bio
401 * @bio_src: Original bio
402 * @gfp_mask: Memory allocation mask
403 *
404 * Description: Called to allocate a bip when cloning a bio
405 */
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask)406 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
407 gfp_t gfp_mask)
408 {
409 struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
410 struct bio_integrity_payload *bip;
411
412 BUG_ON(bip_src == NULL);
413
414 bip = bio_integrity_alloc(bio, gfp_mask, 0);
415 if (IS_ERR(bip))
416 return PTR_ERR(bip);
417
418 bip->bip_vec = bip_src->bip_vec;
419 bip->bip_iter = bip_src->bip_iter;
420 bip->bip_flags = bip_src->bip_flags & BIP_CLONE_FLAGS;
421 bip->app_tag = bip_src->app_tag;
422
423 return 0;
424 }
425