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 */ 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 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 */ 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 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 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 */ 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 */ 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 bool same_page = false; 131 132 if (bvec_try_merge_hw_page(q, bv, page, len, offset, 133 &same_page)) { 134 bip->bip_iter.bi_size += len; 135 return len; 136 } 137 138 if (bip->bip_vcnt >= 139 min(bip->bip_max_vcnt, queue_max_integrity_segments(q))) 140 return 0; 141 142 /* 143 * If the queue doesn't support SG gaps and adding this segment 144 * would create a gap, disallow it. 145 */ 146 if (bvec_gap_to_prev(&q->limits, bv, offset)) 147 return 0; 148 } 149 150 bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset); 151 bip->bip_vcnt++; 152 bip->bip_iter.bi_size += len; 153 154 return len; 155 } 156 EXPORT_SYMBOL(bio_integrity_add_page); 157 158 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec, 159 int nr_vecs, unsigned int len, 160 unsigned int direction) 161 { 162 bool write = direction == ITER_SOURCE; 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, direction, 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 } 216 217 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 } 231 232 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 } 261 262 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 direction, 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 if (bio_data_dir(bio) == READ) 279 direction = ITER_DEST; 280 else 281 direction = ITER_SOURCE; 282 283 nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS + 1); 284 if (nr_vecs > BIO_MAX_VECS) 285 return -E2BIG; 286 if (nr_vecs > UIO_FASTIOV) { 287 bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL); 288 if (!bvec) 289 return -ENOMEM; 290 pages = NULL; 291 } 292 293 copy = !iov_iter_is_aligned(iter, align, align); 294 ret = iov_iter_extract_pages(iter, &pages, bytes, nr_vecs, 0, &offset); 295 if (unlikely(ret < 0)) 296 goto free_bvec; 297 298 nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset); 299 if (pages != stack_pages) 300 kvfree(pages); 301 if (nr_bvecs > queue_max_integrity_segments(q)) 302 copy = true; 303 304 if (copy) 305 ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes, 306 direction); 307 else 308 ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes); 309 if (ret) 310 goto release_pages; 311 if (bvec != stack_vec) 312 kfree(bvec); 313 314 return 0; 315 316 release_pages: 317 bio_integrity_unpin_bvec(bvec, nr_bvecs); 318 free_bvec: 319 if (bvec != stack_vec) 320 kfree(bvec); 321 return ret; 322 } 323 324 static void bio_uio_meta_to_bip(struct bio *bio, struct uio_meta *meta) 325 { 326 struct bio_integrity_payload *bip = bio_integrity(bio); 327 328 if (meta->flags & IO_INTEGRITY_CHK_GUARD) 329 bip->bip_flags |= BIP_CHECK_GUARD; 330 if (meta->flags & IO_INTEGRITY_CHK_APPTAG) 331 bip->bip_flags |= BIP_CHECK_APPTAG; 332 if (meta->flags & IO_INTEGRITY_CHK_REFTAG) 333 bip->bip_flags |= BIP_CHECK_REFTAG; 334 335 bip->app_tag = meta->app_tag; 336 } 337 338 int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta) 339 { 340 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); 341 unsigned int integrity_bytes; 342 int ret; 343 struct iov_iter it; 344 345 if (!bi) 346 return -EINVAL; 347 /* 348 * original meta iterator can be bigger. 349 * process integrity info corresponding to current data buffer only. 350 */ 351 it = meta->iter; 352 integrity_bytes = bio_integrity_bytes(bi, bio_sectors(bio)); 353 if (it.count < integrity_bytes) 354 return -EINVAL; 355 356 /* should fit into two bytes */ 357 BUILD_BUG_ON(IO_INTEGRITY_VALID_FLAGS >= (1 << 16)); 358 359 if (meta->flags && (meta->flags & ~IO_INTEGRITY_VALID_FLAGS)) 360 return -EINVAL; 361 362 it.count = integrity_bytes; 363 ret = bio_integrity_map_user(bio, &it); 364 if (!ret) { 365 bio_uio_meta_to_bip(bio, meta); 366 bip_set_seed(bio_integrity(bio), meta->seed); 367 iov_iter_advance(&meta->iter, integrity_bytes); 368 meta->seed += bio_integrity_intervals(bi, bio_sectors(bio)); 369 } 370 return ret; 371 } 372 373 /** 374 * bio_integrity_advance - Advance integrity vector 375 * @bio: bio whose integrity vector to update 376 * @bytes_done: number of data bytes that have been completed 377 * 378 * Description: This function calculates how many integrity bytes the 379 * number of completed data bytes correspond to and advances the 380 * integrity vector accordingly. 381 */ 382 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done) 383 { 384 struct bio_integrity_payload *bip = bio_integrity(bio); 385 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); 386 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9); 387 388 bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9); 389 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes); 390 } 391 392 /** 393 * bio_integrity_trim - Trim integrity vector 394 * @bio: bio whose integrity vector to update 395 * 396 * Description: Used to trim the integrity vector in a cloned bio. 397 */ 398 void bio_integrity_trim(struct bio *bio) 399 { 400 struct bio_integrity_payload *bip = bio_integrity(bio); 401 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); 402 403 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio)); 404 } 405 EXPORT_SYMBOL(bio_integrity_trim); 406 407 /** 408 * bio_integrity_clone - Callback for cloning bios with integrity metadata 409 * @bio: New bio 410 * @bio_src: Original bio 411 * @gfp_mask: Memory allocation mask 412 * 413 * Description: Called to allocate a bip when cloning a bio 414 */ 415 int bio_integrity_clone(struct bio *bio, struct bio *bio_src, 416 gfp_t gfp_mask) 417 { 418 struct bio_integrity_payload *bip_src = bio_integrity(bio_src); 419 struct bio_integrity_payload *bip; 420 421 BUG_ON(bip_src == NULL); 422 423 bip = bio_integrity_alloc(bio, gfp_mask, 0); 424 if (IS_ERR(bip)) 425 return PTR_ERR(bip); 426 427 bip->bip_vec = bip_src->bip_vec; 428 bip->bip_iter = bip_src->bip_iter; 429 bip->bip_flags = bip_src->bip_flags & BIP_CLONE_FLAGS; 430 bip->app_tag = bip_src->app_tag; 431 432 return 0; 433 } 434