// SPDX-License-Identifier: GPL-2.0 /* * bio-integrity.c - bio data integrity extensions * * Copyright (C) 2007, 2008, 2009 Oracle Corporation * Written by: Martin K. Petersen */ #include #include #include #include #include #include #include "blk.h" static struct kmem_cache *bip_slab; static struct workqueue_struct *kintegrityd_wq; void blk_flush_integrity(void) { flush_workqueue(kintegrityd_wq); } static void __bio_integrity_free(struct bio_set *bs, struct bio_integrity_payload *bip) { if (bs && mempool_initialized(&bs->bio_integrity_pool)) { if (bip->bip_vec) bvec_free(&bs->bvec_integrity_pool, bip->bip_vec, bip->bip_max_vcnt); mempool_free(bip, &bs->bio_integrity_pool); } else { kfree(bip); } } /** * bio_integrity_alloc - Allocate integrity payload and attach it to bio * @bio: bio to attach integrity metadata to * @gfp_mask: Memory allocation mask * @nr_vecs: Number of integrity metadata scatter-gather elements * * Description: This function prepares a bio for attaching integrity * metadata. nr_vecs specifies the maximum number of pages containing * integrity metadata that can be attached. */ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, gfp_t gfp_mask, unsigned int nr_vecs) { struct bio_integrity_payload *bip; struct bio_set *bs = bio->bi_pool; unsigned inline_vecs; if (WARN_ON_ONCE(bio_has_crypt_ctx(bio))) return ERR_PTR(-EOPNOTSUPP); if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) { bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask); inline_vecs = nr_vecs; } else { bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask); inline_vecs = BIO_INLINE_VECS; } if (unlikely(!bip)) return ERR_PTR(-ENOMEM); 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_vec = bvec_alloc(&bs->bvec_integrity_pool, &bip->bip_max_vcnt, gfp_mask); if (!bip->bip_vec) goto err; } else if (nr_vecs) { bip->bip_vec = bip->bip_inline_vecs; } bip->bip_bio = bio; bio->bi_integrity = bip; bio->bi_opf |= REQ_INTEGRITY; return bip; err: __bio_integrity_free(bs, bip); return ERR_PTR(-ENOMEM); } 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 * * Description: Used to free the integrity portion of a bio. Usually * called from bio_free(). */ void bio_integrity_free(struct bio *bio) { struct bio_integrity_payload *bip = bio_integrity(bio); struct bio_set *bs = bio->bi_pool; if (bip->bip_flags & BIP_INTEGRITY_USER) return; if (bip->bip_flags & BIP_BLOCK_INTEGRITY) kfree(bvec_virt(bip->bip_vec)); __bio_integrity_free(bs, bip); bio->bi_integrity = NULL; bio->bi_opf &= ~REQ_INTEGRITY; } /** * bio_integrity_unmap_free_user - Unmap and free bio user integrity payload * @bio: bio containing bip to be unmapped and freed * * Description: Used to unmap and free the user mapped integrity portion of a * bio. Submitter attaching the user integrity buffer is responsible for * unmapping and freeing it during completion. */ void bio_integrity_unmap_free_user(struct bio *bio) { struct bio_integrity_payload *bip = bio_integrity(bio); struct bio_set *bs = bio->bi_pool; if (WARN_ON_ONCE(!(bip->bip_flags & BIP_INTEGRITY_USER))) return; bio_integrity_unmap_user(bip); __bio_integrity_free(bs, bip); bio->bi_integrity = NULL; bio->bi_opf &= ~REQ_INTEGRITY; } EXPORT_SYMBOL(bio_integrity_unmap_free_user); /** * bio_integrity_add_page - Attach integrity metadata * @bio: bio to update * @page: page containing integrity metadata * @len: number of bytes of integrity metadata in page * @offset: start offset within page * * Description: Attach a page containing integrity metadata to bio. */ int bio_integrity_add_page(struct bio *bio, struct page *page, unsigned int len, unsigned int offset) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); struct bio_integrity_payload *bip = bio_integrity(bio); if (((bip->bip_iter.bi_size + len) >> SECTOR_SHIFT) > queue_max_hw_sectors(q)) return 0; if (bip->bip_vcnt > 0) { struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1]; bool same_page = false; if (bvec_try_merge_hw_page(q, bv, page, len, offset, &same_page)) { bip->bip_iter.bi_size += len; return len; } if (bip->bip_vcnt >= min(bip->bip_max_vcnt, queue_max_integrity_segments(q))) return 0; /* * If the queue doesn't support SG gaps and adding this segment * would create a gap, disallow it. */ if (bvec_gap_to_prev(&q->limits, bv, offset)) return 0; } bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset); bip->bip_vcnt++; bip->bip_iter.bi_size += len; return len; } 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; bip->bip_vcnt = nr_vecs; 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; bip->bip_vcnt = nr_vecs; 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 = blk_lim_dma_alignment_and_pad(&q->limits); 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(nr_vecs, sizeof(*bvec), 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_prep - Prepare bio for integrity I/O * @bio: bio to prepare * * Description: Checks if the bio already has an integrity payload attached. * If it does, the payload has been generated by another kernel subsystem, * and we just pass it through. Otherwise allocates integrity payload. * The bio must have data direction, target device and start sector set priot * to calling. In the WRITE case, integrity metadata will be generated using * the block device's integrity function. In the READ case, the buffer * will be prepared for DMA and a suitable end_io handler set up. */ bool bio_integrity_prep(struct bio *bio) { struct bio_integrity_payload *bip; struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); unsigned int len; void *buf; gfp_t gfp = GFP_NOIO; if (!bi) return true; if (!bio_sectors(bio)) return true; /* Already protected? */ if (bio_integrity(bio)) return true; switch (bio_op(bio)) { case REQ_OP_READ: if (bi->flags & BLK_INTEGRITY_NOVERIFY) return true; break; case REQ_OP_WRITE: if (bi->flags & BLK_INTEGRITY_NOGENERATE) return true; /* * Zero the memory allocated to not leak uninitialized kernel * memory to disk for non-integrity metadata where nothing else * initializes the memory. */ if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE) gfp |= __GFP_ZERO; break; default: return true; } /* Allocate kernel buffer for protection data */ len = bio_integrity_bytes(bi, bio_sectors(bio)); buf = kmalloc(len, gfp); if (unlikely(buf == NULL)) { goto err_end_io; } bip = bio_integrity_alloc(bio, GFP_NOIO, 1); if (IS_ERR(bip)) { kfree(buf); goto err_end_io; } bip->bip_flags |= BIP_BLOCK_INTEGRITY; bip_set_seed(bip, bio->bi_iter.bi_sector); if (bi->csum_type == BLK_INTEGRITY_CSUM_IP) bip->bip_flags |= BIP_IP_CHECKSUM; if (bio_integrity_add_page(bio, virt_to_page(buf), len, offset_in_page(buf)) < len) { printk(KERN_ERR "could not attach integrity payload\n"); goto err_end_io; } /* Auto-generate integrity metadata if this is a write */ if (bio_data_dir(bio) == WRITE) blk_integrity_generate(bio); else bip->bio_iter = bio->bi_iter; return true; err_end_io: bio->bi_status = BLK_STS_RESOURCE; bio_endio(bio); return false; } EXPORT_SYMBOL(bio_integrity_prep); /** * bio_integrity_verify_fn - Integrity I/O completion worker * @work: Work struct stored in bio to be verified * * Description: This workqueue function is called to complete a READ * request. The function verifies the transferred integrity metadata * and then calls the original bio end_io function. */ static void bio_integrity_verify_fn(struct work_struct *work) { struct bio_integrity_payload *bip = container_of(work, struct bio_integrity_payload, bip_work); struct bio *bio = bip->bip_bio; blk_integrity_verify(bio); bio_integrity_free(bio); bio_endio(bio); } /** * __bio_integrity_endio - Integrity I/O completion function * @bio: Protected bio * * Description: Completion for integrity I/O * * Normally I/O completion is done in interrupt context. However, * verifying I/O integrity is a time-consuming task which must be run * in process context. This function postpones completion * accordingly. */ bool __bio_integrity_endio(struct bio *bio) { struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); struct bio_integrity_payload *bip = bio_integrity(bio); if (bio_op(bio) == REQ_OP_READ && !bio->bi_status && (bip->bip_flags & BIP_BLOCK_INTEGRITY) && bi->csum_type) { INIT_WORK(&bip->bip_work, bio_integrity_verify_fn); queue_work(kintegrityd_wq, &bip->bip_work); return false; } bio_integrity_free(bio); return true; } /** * bio_integrity_advance - Advance integrity vector * @bio: bio whose integrity vector to update * @bytes_done: number of data bytes that have been completed * * Description: This function calculates how many integrity bytes the * number of completed data bytes correspond to and advances the * integrity vector accordingly. */ void bio_integrity_advance(struct bio *bio, unsigned int bytes_done) { struct bio_integrity_payload *bip = bio_integrity(bio); struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9); bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9); bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes); } /** * bio_integrity_trim - Trim integrity vector * @bio: bio whose integrity vector to update * * Description: Used to trim the integrity vector in a cloned bio. */ void bio_integrity_trim(struct bio *bio) { struct bio_integrity_payload *bip = bio_integrity(bio); struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio)); } EXPORT_SYMBOL(bio_integrity_trim); /** * bio_integrity_clone - Callback for cloning bios with integrity metadata * @bio: New bio * @bio_src: Original bio * @gfp_mask: Memory allocation mask * * Description: Called to allocate a bip when cloning a bio */ int bio_integrity_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp_mask) { struct bio_integrity_payload *bip_src = bio_integrity(bio_src); struct bio_integrity_payload *bip; BUG_ON(bip_src == NULL); bip = bio_integrity_alloc(bio, gfp_mask, 0); if (IS_ERR(bip)) return PTR_ERR(bip); bip->bip_vec = bip_src->bip_vec; bip->bip_iter = bip_src->bip_iter; bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY; return 0; } int bioset_integrity_create(struct bio_set *bs, int pool_size) { if (mempool_initialized(&bs->bio_integrity_pool)) return 0; if (mempool_init_slab_pool(&bs->bio_integrity_pool, pool_size, bip_slab)) return -1; if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) { mempool_exit(&bs->bio_integrity_pool); return -1; } return 0; } EXPORT_SYMBOL(bioset_integrity_create); void bioset_integrity_free(struct bio_set *bs) { mempool_exit(&bs->bio_integrity_pool); mempool_exit(&bs->bvec_integrity_pool); } void __init bio_integrity_init(void) { /* * kintegrityd won't block much but may burn a lot of CPU cycles. * Make it highpri CPU intensive wq with max concurrency of 1. */ kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1); if (!kintegrityd_wq) panic("Failed to create kintegrityd\n"); bip_slab = kmem_cache_create("bio_integrity_payload", sizeof(struct bio_integrity_payload) + sizeof(struct bio_vec) * BIO_INLINE_VECS, 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); }