diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/bio-integrity.c | 218 |
1 files changed, 216 insertions, 2 deletions
diff --git a/block/bio-integrity.c b/block/bio-integrity.c index ec8ac8cf6e1b..feef615e2c9c 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -69,15 +69,15 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, memset(bip, 0, sizeof(*bip)); + /* always report as many vecs as asked explicitly, not inline vecs */ + bip->bip_max_vcnt = nr_vecs; if (nr_vecs > inline_vecs) { - bip->bip_max_vcnt = nr_vecs; bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool, &bip->bip_max_vcnt, gfp_mask); if (!bip->bip_vec) goto err; } else { bip->bip_vec = bip->bip_inline_vecs; - bip->bip_max_vcnt = inline_vecs; } bip->bip_bio = bio; @@ -91,6 +91,47 @@ err: } EXPORT_SYMBOL(bio_integrity_alloc); +static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs, + bool dirty) +{ + int i; + + for (i = 0; i < nr_vecs; i++) { + if (dirty && !PageCompound(bv[i].bv_page)) + set_page_dirty_lock(bv[i].bv_page); + unpin_user_page(bv[i].bv_page); + } +} + +static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip) +{ + unsigned short nr_vecs = bip->bip_max_vcnt - 1; + struct bio_vec *copy = &bip->bip_vec[1]; + size_t bytes = bip->bip_iter.bi_size; + struct iov_iter iter; + int ret; + + iov_iter_bvec(&iter, ITER_DEST, copy, nr_vecs, bytes); + ret = copy_to_iter(bvec_virt(bip->bip_vec), bytes, &iter); + WARN_ON_ONCE(ret != bytes); + + bio_integrity_unpin_bvec(copy, nr_vecs, true); +} + +static void bio_integrity_unmap_user(struct bio_integrity_payload *bip) +{ + bool dirty = bio_data_dir(bip->bip_bio) == READ; + + if (bip->bip_flags & BIP_COPY_USER) { + if (dirty) + bio_integrity_uncopy_user(bip); + kfree(bvec_virt(bip->bip_vec)); + return; + } + + bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt, dirty); +} + /** * bio_integrity_free - Free bio integrity payload * @bio: bio containing bip to be freed @@ -105,6 +146,8 @@ void bio_integrity_free(struct bio *bio) if (bip->bip_flags & BIP_BLOCK_INTEGRITY) kfree(bvec_virt(bip->bip_vec)); + else if (bip->bip_flags & BIP_INTEGRITY_USER) + bio_integrity_unmap_user(bip); __bio_integrity_free(bs, bip); bio->bi_integrity = NULL; @@ -160,6 +203,177 @@ int bio_integrity_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_integrity_add_page); +static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec, + int nr_vecs, unsigned int len, + unsigned int direction, u32 seed) +{ + bool write = direction == ITER_SOURCE; + struct bio_integrity_payload *bip; + struct iov_iter iter; + void *buf; + int ret; + + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (write) { + iov_iter_bvec(&iter, direction, bvec, nr_vecs, len); + if (!copy_from_iter_full(buf, len, &iter)) { + ret = -EFAULT; + goto free_buf; + } + + bip = bio_integrity_alloc(bio, GFP_KERNEL, 1); + } else { + memset(buf, 0, len); + + /* + * We need to preserve the original bvec and the number of vecs + * in it for completion handling + */ + bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1); + } + + if (IS_ERR(bip)) { + ret = PTR_ERR(bip); + goto free_buf; + } + + if (write) + bio_integrity_unpin_bvec(bvec, nr_vecs, false); + else + memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec)); + + ret = bio_integrity_add_page(bio, virt_to_page(buf), len, + offset_in_page(buf)); + if (ret != len) { + ret = -ENOMEM; + goto free_bip; + } + + bip->bip_flags |= BIP_INTEGRITY_USER | BIP_COPY_USER; + bip->bip_iter.bi_sector = seed; + return 0; +free_bip: + bio_integrity_free(bio); +free_buf: + kfree(buf); + return ret; +} + +static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec, + int nr_vecs, unsigned int len, u32 seed) +{ + struct bio_integrity_payload *bip; + + bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs); + if (IS_ERR(bip)) + return PTR_ERR(bip); + + memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec)); + bip->bip_flags |= BIP_INTEGRITY_USER; + bip->bip_iter.bi_sector = seed; + bip->bip_iter.bi_size = len; + return 0; +} + +static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages, + int nr_vecs, ssize_t bytes, ssize_t offset) +{ + unsigned int nr_bvecs = 0; + int i, j; + + for (i = 0; i < nr_vecs; i = j) { + size_t size = min_t(size_t, bytes, PAGE_SIZE - offset); + struct folio *folio = page_folio(pages[i]); + + bytes -= size; + for (j = i + 1; j < nr_vecs; j++) { + size_t next = min_t(size_t, PAGE_SIZE, bytes); + + if (page_folio(pages[j]) != folio || + pages[j] != pages[j - 1] + 1) + break; + unpin_user_page(pages[j]); + size += next; + bytes -= next; + } + + bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset); + offset = 0; + nr_bvecs++; + } + + return nr_bvecs; +} + +int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes, + u32 seed) +{ + struct request_queue *q = bdev_get_queue(bio->bi_bdev); + unsigned int align = q->dma_pad_mask | queue_dma_alignment(q); + struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages; + struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec; + unsigned int direction, nr_bvecs; + struct iov_iter iter; + int ret, nr_vecs; + size_t offset; + bool copy; + + if (bio_integrity(bio)) + return -EINVAL; + if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q)) + return -E2BIG; + + if (bio_data_dir(bio) == READ) + direction = ITER_DEST; + else + direction = ITER_SOURCE; + + iov_iter_ubuf(&iter, direction, ubuf, bytes); + nr_vecs = iov_iter_npages(&iter, BIO_MAX_VECS + 1); + if (nr_vecs > BIO_MAX_VECS) + return -E2BIG; + if (nr_vecs > UIO_FASTIOV) { + bvec = kcalloc(sizeof(*bvec), nr_vecs, GFP_KERNEL); + if (!bvec) + return -ENOMEM; + pages = NULL; + } + + copy = !iov_iter_is_aligned(&iter, align, align); + ret = iov_iter_extract_pages(&iter, &pages, bytes, nr_vecs, 0, &offset); + if (unlikely(ret < 0)) + goto free_bvec; + + nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset); + if (pages != stack_pages) + kvfree(pages); + if (nr_bvecs > queue_max_integrity_segments(q)) + copy = true; + + if (copy) + ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes, + direction, seed); + else + ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes, seed); + if (ret) + goto release_pages; + if (bvec != stack_vec) + kfree(bvec); + + return 0; + +release_pages: + bio_integrity_unpin_bvec(bvec, nr_bvecs, false); +free_bvec: + if (bvec != stack_vec) + kfree(bvec); + return ret; +} +EXPORT_SYMBOL_GPL(bio_integrity_map_user); + /** * bio_integrity_process - Process integrity metadata for a bio * @bio: bio to generate/verify integrity metadata for |