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 (!zone_device_pages_have_same_pgmap(bv->bv_page, page))
132 return 0;
133
134 if (bvec_try_merge_hw_page(q, bv, page, len, offset)) {
135 bip->bip_iter.bi_size += len;
136 return len;
137 }
138
139 if (bip->bip_vcnt >=
140 min(bip->bip_max_vcnt, queue_max_integrity_segments(q)))
141 return 0;
142
143 /*
144 * If the queue doesn't support SG gaps and adding this segment
145 * would create a gap, disallow it.
146 */
147 if (bvec_gap_to_prev(&q->limits, bv, offset))
148 return 0;
149 }
150
151 bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
152 bip->bip_vcnt++;
153 bip->bip_iter.bi_size += len;
154
155 return len;
156 }
157 EXPORT_SYMBOL(bio_integrity_add_page);
158
bio_integrity_copy_user(struct bio * bio,struct bio_vec * bvec,int nr_vecs,unsigned int len)159 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec,
160 int nr_vecs, unsigned int len)
161 {
162 bool write = op_is_write(bio_op(bio));
163 struct bio_integrity_payload *bip;
164 struct iov_iter iter;
165 void *buf;
166 int ret;
167
168 buf = kmalloc(len, GFP_KERNEL);
169 if (!buf)
170 return -ENOMEM;
171
172 if (write) {
173 iov_iter_bvec(&iter, ITER_SOURCE, bvec, nr_vecs, len);
174 if (!copy_from_iter_full(buf, len, &iter)) {
175 ret = -EFAULT;
176 goto free_buf;
177 }
178
179 bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
180 } else {
181 memset(buf, 0, len);
182
183 /*
184 * We need to preserve the original bvec and the number of vecs
185 * in it for completion handling
186 */
187 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1);
188 }
189
190 if (IS_ERR(bip)) {
191 ret = PTR_ERR(bip);
192 goto free_buf;
193 }
194
195 if (write)
196 bio_integrity_unpin_bvec(bvec, nr_vecs);
197 else
198 memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));
199
200 ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
201 offset_in_page(buf));
202 if (ret != len) {
203 ret = -ENOMEM;
204 goto free_bip;
205 }
206
207 bip->bip_flags |= BIP_COPY_USER;
208 bip->bip_vcnt = nr_vecs;
209 return 0;
210 free_bip:
211 bio_integrity_free(bio);
212 free_buf:
213 kfree(buf);
214 return ret;
215 }
216
bio_integrity_init_user(struct bio * bio,struct bio_vec * bvec,int nr_vecs,unsigned int len)217 static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec,
218 int nr_vecs, unsigned int len)
219 {
220 struct bio_integrity_payload *bip;
221
222 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs);
223 if (IS_ERR(bip))
224 return PTR_ERR(bip);
225
226 memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec));
227 bip->bip_iter.bi_size = len;
228 bip->bip_vcnt = nr_vecs;
229 return 0;
230 }
231
bvec_from_pages(struct bio_vec * bvec,struct page ** pages,int nr_vecs,ssize_t bytes,ssize_t offset)232 static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
233 int nr_vecs, ssize_t bytes, ssize_t offset)
234 {
235 unsigned int nr_bvecs = 0;
236 int i, j;
237
238 for (i = 0; i < nr_vecs; i = j) {
239 size_t size = min_t(size_t, bytes, PAGE_SIZE - offset);
240 struct folio *folio = page_folio(pages[i]);
241
242 bytes -= size;
243 for (j = i + 1; j < nr_vecs; j++) {
244 size_t next = min_t(size_t, PAGE_SIZE, bytes);
245
246 if (page_folio(pages[j]) != folio ||
247 pages[j] != pages[j - 1] + 1)
248 break;
249 unpin_user_page(pages[j]);
250 size += next;
251 bytes -= next;
252 }
253
254 bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset);
255 offset = 0;
256 nr_bvecs++;
257 }
258
259 return nr_bvecs;
260 }
261
bio_integrity_map_user(struct bio * bio,struct iov_iter * iter)262 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter)
263 {
264 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
265 unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits);
266 struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages;
267 struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
268 size_t offset, bytes = iter->count;
269 unsigned int nr_bvecs;
270 int ret, nr_vecs;
271 bool copy;
272
273 if (bio_integrity(bio))
274 return -EINVAL;
275 if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q))
276 return -E2BIG;
277
278 nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS + 1);
279 if (nr_vecs > BIO_MAX_VECS)
280 return -E2BIG;
281 if (nr_vecs > UIO_FASTIOV) {
282 bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL);
283 if (!bvec)
284 return -ENOMEM;
285 pages = NULL;
286 }
287
288 copy = !iov_iter_is_aligned(iter, align, align);
289 ret = iov_iter_extract_pages(iter, &pages, bytes, nr_vecs, 0, &offset);
290 if (unlikely(ret < 0))
291 goto free_bvec;
292
293 nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
294 if (pages != stack_pages)
295 kvfree(pages);
296 if (nr_bvecs > queue_max_integrity_segments(q))
297 copy = true;
298
299 if (copy)
300 ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes);
301 else
302 ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes);
303 if (ret)
304 goto release_pages;
305 if (bvec != stack_vec)
306 kfree(bvec);
307
308 return 0;
309
310 release_pages:
311 bio_integrity_unpin_bvec(bvec, nr_bvecs);
312 free_bvec:
313 if (bvec != stack_vec)
314 kfree(bvec);
315 return ret;
316 }
317
bio_uio_meta_to_bip(struct bio * bio,struct uio_meta * meta)318 static void bio_uio_meta_to_bip(struct bio *bio, struct uio_meta *meta)
319 {
320 struct bio_integrity_payload *bip = bio_integrity(bio);
321
322 if (meta->flags & IO_INTEGRITY_CHK_GUARD)
323 bip->bip_flags |= BIP_CHECK_GUARD;
324 if (meta->flags & IO_INTEGRITY_CHK_APPTAG)
325 bip->bip_flags |= BIP_CHECK_APPTAG;
326 if (meta->flags & IO_INTEGRITY_CHK_REFTAG)
327 bip->bip_flags |= BIP_CHECK_REFTAG;
328
329 bip->app_tag = meta->app_tag;
330 }
331
bio_integrity_map_iter(struct bio * bio,struct uio_meta * meta)332 int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta)
333 {
334 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
335 unsigned int integrity_bytes;
336 int ret;
337 struct iov_iter it;
338
339 if (!bi)
340 return -EINVAL;
341 /*
342 * original meta iterator can be bigger.
343 * process integrity info corresponding to current data buffer only.
344 */
345 it = meta->iter;
346 integrity_bytes = bio_integrity_bytes(bi, bio_sectors(bio));
347 if (it.count < integrity_bytes)
348 return -EINVAL;
349
350 /* should fit into two bytes */
351 BUILD_BUG_ON(IO_INTEGRITY_VALID_FLAGS >= (1 << 16));
352
353 if (meta->flags && (meta->flags & ~IO_INTEGRITY_VALID_FLAGS))
354 return -EINVAL;
355
356 it.count = integrity_bytes;
357 ret = bio_integrity_map_user(bio, &it);
358 if (!ret) {
359 bio_uio_meta_to_bip(bio, meta);
360 bip_set_seed(bio_integrity(bio), meta->seed);
361 iov_iter_advance(&meta->iter, integrity_bytes);
362 meta->seed += bio_integrity_intervals(bi, bio_sectors(bio));
363 }
364 return ret;
365 }
366
367 /**
368 * bio_integrity_advance - Advance integrity vector
369 * @bio: bio whose integrity vector to update
370 * @bytes_done: number of data bytes that have been completed
371 *
372 * Description: This function calculates how many integrity bytes the
373 * number of completed data bytes correspond to and advances the
374 * integrity vector accordingly.
375 */
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)376 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
377 {
378 struct bio_integrity_payload *bip = bio_integrity(bio);
379 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
380 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
381
382 bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
383 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
384 }
385
386 /**
387 * bio_integrity_trim - Trim integrity vector
388 * @bio: bio whose integrity vector to update
389 *
390 * Description: Used to trim the integrity vector in a cloned bio.
391 */
bio_integrity_trim(struct bio * bio)392 void bio_integrity_trim(struct bio *bio)
393 {
394 struct bio_integrity_payload *bip = bio_integrity(bio);
395 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
396
397 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
398 }
399 EXPORT_SYMBOL(bio_integrity_trim);
400
401 /**
402 * bio_integrity_clone - Callback for cloning bios with integrity metadata
403 * @bio: New bio
404 * @bio_src: Original bio
405 * @gfp_mask: Memory allocation mask
406 *
407 * Description: Called to allocate a bip when cloning a bio
408 */
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask)409 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
410 gfp_t gfp_mask)
411 {
412 struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
413 struct bio_integrity_payload *bip;
414
415 BUG_ON(bip_src == NULL);
416
417 bip = bio_integrity_alloc(bio, gfp_mask, 0);
418 if (IS_ERR(bip))
419 return PTR_ERR(bip);
420
421 bip->bip_vec = bip_src->bip_vec;
422 bip->bip_iter = bip_src->bip_iter;
423 bip->bip_flags = bip_src->bip_flags & BIP_CLONE_FLAGS;
424 bip->app_tag = bip_src->app_tag;
425
426 return 0;
427 }
428