diff options
Diffstat (limited to 'block/t10-pi.c')
| -rw-r--r-- | block/t10-pi.c | 567 |
1 files changed, 567 insertions, 0 deletions
diff --git a/block/t10-pi.c b/block/t10-pi.c new file mode 100644 index 000000000..a19b4e102 --- /dev/null +++ b/block/t10-pi.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * t10_pi.c - Functions for generating and verifying T10 Protection + * Information. + */ + +#include <linux/t10-pi.h> +#include <linux/blk-integrity.h> +#include <linux/crc-t10dif.h> +#include <linux/crc64.h> +#include <net/checksum.h> +#include <linux/unaligned.h> +#include "blk.h" + +#define APP_TAG_ESCAPE 0xffff +#define REF_TAG_ESCAPE 0xffffffff + +/* + * This union is used for onstack allocations when the pi field is split across + * segments. blk_validate_integrity_limits() guarantees pi_tuple_size matches + * the sizeof one of these two types. + */ +union pi_tuple { + struct crc64_pi_tuple crc64_pi; + struct t10_pi_tuple t10_pi; +}; + +struct blk_integrity_iter { + struct bio *bio; + struct bio_integrity_payload *bip; + struct blk_integrity *bi; + struct bvec_iter data_iter; + struct bvec_iter prot_iter; + unsigned int interval_remaining; + u64 seed; + u64 csum; +}; + +static void blk_calculate_guard(struct blk_integrity_iter *iter, void *data, + unsigned int len) +{ + switch (iter->bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + iter->csum = crc64_nvme(iter->csum, data, len); + break; + case BLK_INTEGRITY_CSUM_CRC: + iter->csum = crc_t10dif_update(iter->csum, data, len); + break; + case BLK_INTEGRITY_CSUM_IP: + iter->csum = (__force u32)csum_partial(data, len, + (__force __wsum)iter->csum); + break; + default: + WARN_ON_ONCE(1); + iter->csum = U64_MAX; + break; + } +} + +static void blk_integrity_csum_finish(struct blk_integrity_iter *iter) +{ + switch (iter->bi->csum_type) { + case BLK_INTEGRITY_CSUM_IP: + iter->csum = (__force u16)csum_fold((__force __wsum)iter->csum); + break; + default: + break; + } +} + +/* + * Update the csum for formats that have metadata padding in front of the data + * integrity field + */ +static void blk_integrity_csum_offset(struct blk_integrity_iter *iter) +{ + unsigned int offset = iter->bi->pi_offset; + struct bio_vec *bvec = iter->bip->bip_vec; + + while (offset > 0) { + struct bio_vec pbv = bvec_iter_bvec(bvec, iter->prot_iter); + unsigned int len = min(pbv.bv_len, offset); + void *prot_buf = bvec_kmap_local(&pbv); + + blk_calculate_guard(iter, prot_buf, len); + kunmap_local(prot_buf); + offset -= len; + bvec_iter_advance_single(bvec, &iter->prot_iter, len); + } + blk_integrity_csum_finish(iter); +} + +static void blk_integrity_copy_from_tuple(struct bio_integrity_payload *bip, + struct bvec_iter *iter, void *tuple, + unsigned int tuple_size) +{ + while (tuple_size) { + struct bio_vec pbv = bvec_iter_bvec(bip->bip_vec, *iter); + unsigned int len = min(tuple_size, pbv.bv_len); + void *prot_buf = bvec_kmap_local(&pbv); + + memcpy(prot_buf, tuple, len); + kunmap_local(prot_buf); + bvec_iter_advance_single(bip->bip_vec, iter, len); + tuple_size -= len; + tuple += len; + } +} + +static void blk_integrity_copy_to_tuple(struct bio_integrity_payload *bip, + struct bvec_iter *iter, void *tuple, + unsigned int tuple_size) +{ + while (tuple_size) { + struct bio_vec pbv = bvec_iter_bvec(bip->bip_vec, *iter); + unsigned int len = min(tuple_size, pbv.bv_len); + void *prot_buf = bvec_kmap_local(&pbv); + + memcpy(tuple, prot_buf, len); + kunmap_local(prot_buf); + bvec_iter_advance_single(bip->bip_vec, iter, len); + tuple_size -= len; + tuple += len; + } +} + +static bool ext_pi_ref_escape(const u8 ref_tag[6]) +{ + static const u8 ref_escape[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; + + return memcmp(ref_tag, ref_escape, sizeof(ref_escape)) == 0; +} + +static blk_status_t blk_verify_ext_pi(struct blk_integrity_iter *iter, + struct crc64_pi_tuple *pi) +{ + u64 seed = lower_48_bits(iter->seed); + u64 guard = get_unaligned_be64(&pi->guard_tag); + u64 ref = get_unaligned_be48(pi->ref_tag); + u16 app = get_unaligned_be16(&pi->app_tag); + + if (iter->bi->flags & BLK_INTEGRITY_REF_TAG) { + if (app == APP_TAG_ESCAPE) + return BLK_STS_OK; + if (ref != seed) { + pr_err("%s: ref tag error at location %llu (rcvd %llu)\n", + iter->bio->bi_bdev->bd_disk->disk_name, seed, + ref); + return BLK_STS_PROTECTION; + } + } else if (app == APP_TAG_ESCAPE && ext_pi_ref_escape(pi->ref_tag)) { + return BLK_STS_OK; + } + + if (guard != iter->csum) { + pr_err("%s: guard tag error at sector %llu (rcvd %016llx, want %016llx)\n", + iter->bio->bi_bdev->bd_disk->disk_name, iter->seed, + guard, iter->csum); + return BLK_STS_PROTECTION; + } + + return BLK_STS_OK; +} + +static blk_status_t blk_verify_pi(struct blk_integrity_iter *iter, + struct t10_pi_tuple *pi, u16 guard) +{ + u32 seed = lower_32_bits(iter->seed); + u32 ref = get_unaligned_be32(&pi->ref_tag); + u16 app = get_unaligned_be16(&pi->app_tag); + + if (iter->bi->flags & BLK_INTEGRITY_REF_TAG) { + if (app == APP_TAG_ESCAPE) + return BLK_STS_OK; + if (ref != seed) { + pr_err("%s: ref tag error at location %u (rcvd %u)\n", + iter->bio->bi_bdev->bd_disk->disk_name, seed, + ref); + return BLK_STS_PROTECTION; + } + } else if (app == APP_TAG_ESCAPE && ref == REF_TAG_ESCAPE) { + return BLK_STS_OK; + } + + if (guard != (u16)iter->csum) { + pr_err("%s: guard tag error at sector %llu (rcvd %04x, want %04x)\n", + iter->bio->bi_bdev->bd_disk->disk_name, iter->seed, + guard, (u16)iter->csum); + return BLK_STS_PROTECTION; + } + + return BLK_STS_OK; +} + +static blk_status_t blk_verify_t10_pi(struct blk_integrity_iter *iter, + struct t10_pi_tuple *pi) +{ + u16 guard = get_unaligned_be16(&pi->guard_tag); + + return blk_verify_pi(iter, pi, guard); +} + +static blk_status_t blk_verify_ip_pi(struct blk_integrity_iter *iter, + struct t10_pi_tuple *pi) +{ + u16 guard = get_unaligned((u16 *)&pi->guard_tag); + + return blk_verify_pi(iter, pi, guard); +} + +static blk_status_t blk_integrity_verify(struct blk_integrity_iter *iter, + union pi_tuple *tuple) +{ + switch (iter->bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + return blk_verify_ext_pi(iter, &tuple->crc64_pi); + case BLK_INTEGRITY_CSUM_CRC: + return blk_verify_t10_pi(iter, &tuple->t10_pi); + case BLK_INTEGRITY_CSUM_IP: + return blk_verify_ip_pi(iter, &tuple->t10_pi); + default: + return BLK_STS_OK; + } +} + +static void blk_set_ext_pi(struct blk_integrity_iter *iter, + struct crc64_pi_tuple *pi) +{ + put_unaligned_be64(iter->csum, &pi->guard_tag); + put_unaligned_be16(0, &pi->app_tag); + put_unaligned_be48(iter->seed, &pi->ref_tag); +} + +static void blk_set_pi(struct blk_integrity_iter *iter, + struct t10_pi_tuple *pi, __be16 csum) +{ + put_unaligned(csum, &pi->guard_tag); + put_unaligned_be16(0, &pi->app_tag); + put_unaligned_be32(iter->seed, &pi->ref_tag); +} + +static void blk_set_t10_pi(struct blk_integrity_iter *iter, + struct t10_pi_tuple *pi) +{ + blk_set_pi(iter, pi, cpu_to_be16((u16)iter->csum)); +} + +static void blk_set_ip_pi(struct blk_integrity_iter *iter, + struct t10_pi_tuple *pi) +{ + blk_set_pi(iter, pi, (__force __be16)(u16)iter->csum); +} + +static void blk_integrity_set(struct blk_integrity_iter *iter, + union pi_tuple *tuple) +{ + switch (iter->bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + return blk_set_ext_pi(iter, &tuple->crc64_pi); + case BLK_INTEGRITY_CSUM_CRC: + return blk_set_t10_pi(iter, &tuple->t10_pi); + case BLK_INTEGRITY_CSUM_IP: + return blk_set_ip_pi(iter, &tuple->t10_pi); + default: + WARN_ON_ONCE(1); + return; + } +} + +static blk_status_t blk_integrity_interval(struct blk_integrity_iter *iter, + bool verify) +{ + blk_status_t ret = BLK_STS_OK; + union pi_tuple tuple; + void *ptuple = &tuple; + struct bio_vec pbv; + + blk_integrity_csum_offset(iter); + pbv = bvec_iter_bvec(iter->bip->bip_vec, iter->prot_iter); + if (pbv.bv_len >= iter->bi->pi_tuple_size) { + ptuple = bvec_kmap_local(&pbv); + bvec_iter_advance_single(iter->bip->bip_vec, &iter->prot_iter, + iter->bi->metadata_size - iter->bi->pi_offset); + } else if (verify) { + blk_integrity_copy_to_tuple(iter->bip, &iter->prot_iter, + ptuple, iter->bi->pi_tuple_size); + } + + if (verify) + ret = blk_integrity_verify(iter, ptuple); + else + blk_integrity_set(iter, ptuple); + + if (likely(ptuple != &tuple)) { + kunmap_local(ptuple); + } else if (!verify) { + blk_integrity_copy_from_tuple(iter->bip, &iter->prot_iter, + ptuple, iter->bi->pi_tuple_size); + } + + iter->interval_remaining = 1 << iter->bi->interval_exp; + iter->csum = 0; + iter->seed++; + return ret; +} + +static blk_status_t blk_integrity_iterate(struct bio *bio, + struct bvec_iter *data_iter, + bool verify) +{ + struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); + struct bio_integrity_payload *bip = bio_integrity(bio); + struct blk_integrity_iter iter = { + .bio = bio, + .bip = bip, + .bi = bi, + .data_iter = *data_iter, + .prot_iter = bip->bip_iter, + .interval_remaining = 1 << bi->interval_exp, + .seed = data_iter->bi_sector, + .csum = 0, + }; + blk_status_t ret = BLK_STS_OK; + + while (iter.data_iter.bi_size && ret == BLK_STS_OK) { + struct bio_vec bv = bvec_iter_bvec(iter.bio->bi_io_vec, + iter.data_iter); + void *kaddr = bvec_kmap_local(&bv); + void *data = kaddr; + unsigned int len; + + bvec_iter_advance_single(iter.bio->bi_io_vec, &iter.data_iter, + bv.bv_len); + while (bv.bv_len && ret == BLK_STS_OK) { + len = min(iter.interval_remaining, bv.bv_len); + blk_calculate_guard(&iter, data, len); + bv.bv_len -= len; + data += len; + iter.interval_remaining -= len; + if (!iter.interval_remaining) + ret = blk_integrity_interval(&iter, verify); + } + kunmap_local(kaddr); + } + + return ret; +} + +void bio_integrity_generate(struct bio *bio) +{ + struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); + + switch (bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + case BLK_INTEGRITY_CSUM_CRC: + case BLK_INTEGRITY_CSUM_IP: + blk_integrity_iterate(bio, &bio->bi_iter, false); + break; + default: + break; + } +} + +blk_status_t bio_integrity_verify(struct bio *bio, struct bvec_iter *saved_iter) +{ + struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk); + + switch (bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + case BLK_INTEGRITY_CSUM_CRC: + case BLK_INTEGRITY_CSUM_IP: + return blk_integrity_iterate(bio, saved_iter, true); + default: + break; + } + + return BLK_STS_OK; +} + +/* + * Advance @iter past the protection offset for protection formats that + * contain front padding on the metadata region. + */ +static void blk_pi_advance_offset(struct blk_integrity *bi, + struct bio_integrity_payload *bip, + struct bvec_iter *iter) +{ + unsigned int offset = bi->pi_offset; + + while (offset > 0) { + struct bio_vec bv = mp_bvec_iter_bvec(bip->bip_vec, *iter); + unsigned int len = min(bv.bv_len, offset); + + bvec_iter_advance_single(bip->bip_vec, iter, len); + offset -= len; + } +} + +static void *blk_tuple_remap_begin(union pi_tuple *tuple, + struct blk_integrity *bi, + struct bio_integrity_payload *bip, + struct bvec_iter *iter) +{ + struct bvec_iter titer; + struct bio_vec pbv; + + blk_pi_advance_offset(bi, bip, iter); + pbv = bvec_iter_bvec(bip->bip_vec, *iter); + if (likely(pbv.bv_len >= bi->pi_tuple_size)) + return bvec_kmap_local(&pbv); + + /* + * We need to preserve the state of the original iter for the + * copy_from_tuple at the end, so make a temp iter for here. + */ + titer = *iter; + blk_integrity_copy_to_tuple(bip, &titer, tuple, bi->pi_tuple_size); + return tuple; +} + +static void blk_tuple_remap_end(union pi_tuple *tuple, void *ptuple, + struct blk_integrity *bi, + struct bio_integrity_payload *bip, + struct bvec_iter *iter) +{ + unsigned int len = bi->metadata_size - bi->pi_offset; + + if (likely(ptuple != tuple)) { + kunmap_local(ptuple); + } else { + blk_integrity_copy_from_tuple(bip, iter, ptuple, + bi->pi_tuple_size); + len -= bi->pi_tuple_size; + } + + bvec_iter_advance(bip->bip_vec, iter, len); +} + +static void blk_set_ext_unmap_ref(struct crc64_pi_tuple *pi, u64 virt, + u64 ref_tag) +{ + u64 ref = get_unaligned_be48(&pi->ref_tag); + + if (ref == lower_48_bits(ref_tag) && ref != lower_48_bits(virt)) + put_unaligned_be48(virt, pi->ref_tag); +} + +static void blk_set_t10_unmap_ref(struct t10_pi_tuple *pi, u32 virt, + u32 ref_tag) +{ + u32 ref = get_unaligned_be32(&pi->ref_tag); + + if (ref == ref_tag && ref != virt) + put_unaligned_be32(virt, &pi->ref_tag); +} + +static void blk_reftag_remap_complete(struct blk_integrity *bi, + union pi_tuple *tuple, u64 virt, u64 ref) +{ + switch (bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + blk_set_ext_unmap_ref(&tuple->crc64_pi, virt, ref); + break; + case BLK_INTEGRITY_CSUM_CRC: + case BLK_INTEGRITY_CSUM_IP: + blk_set_t10_unmap_ref(&tuple->t10_pi, virt, ref); + break; + default: + WARN_ON_ONCE(1); + break; + } +} + +static void blk_set_ext_map_ref(struct crc64_pi_tuple *pi, u64 virt, + u64 ref_tag) +{ + u64 ref = get_unaligned_be48(&pi->ref_tag); + + if (ref == lower_48_bits(virt) && ref != ref_tag) + put_unaligned_be48(ref_tag, pi->ref_tag); +} + +static void blk_set_t10_map_ref(struct t10_pi_tuple *pi, u32 virt, u32 ref_tag) +{ + u32 ref = get_unaligned_be32(&pi->ref_tag); + + if (ref == virt && ref != ref_tag) + put_unaligned_be32(ref_tag, &pi->ref_tag); +} + +static void blk_reftag_remap_prepare(struct blk_integrity *bi, + union pi_tuple *tuple, + u64 virt, u64 ref) +{ + switch (bi->csum_type) { + case BLK_INTEGRITY_CSUM_CRC64: + blk_set_ext_map_ref(&tuple->crc64_pi, virt, ref); + break; + case BLK_INTEGRITY_CSUM_CRC: + case BLK_INTEGRITY_CSUM_IP: + blk_set_t10_map_ref(&tuple->t10_pi, virt, ref); + break; + default: + WARN_ON_ONCE(1); + break; + } +} + +static void __blk_reftag_remap(struct bio *bio, struct blk_integrity *bi, + unsigned *intervals, u64 *ref, bool prep) +{ + struct bio_integrity_payload *bip = bio_integrity(bio); + struct bvec_iter iter = bip->bip_iter; + u64 virt = bip_get_seed(bip); + union pi_tuple *ptuple; + union pi_tuple tuple; + + if (prep && bip->bip_flags & BIP_MAPPED_INTEGRITY) { + *ref += bio->bi_iter.bi_size >> bi->interval_exp; + return; + } + + while (iter.bi_size && *intervals) { + ptuple = blk_tuple_remap_begin(&tuple, bi, bip, &iter); + + if (prep) + blk_reftag_remap_prepare(bi, ptuple, virt, *ref); + else + blk_reftag_remap_complete(bi, ptuple, virt, *ref); + + blk_tuple_remap_end(&tuple, ptuple, bi, bip, &iter); + (*intervals)--; + (*ref)++; + virt++; + } + + if (prep) + bip->bip_flags |= BIP_MAPPED_INTEGRITY; +} + +static void blk_integrity_remap(struct request *rq, unsigned int nr_bytes, + bool prep) +{ + struct blk_integrity *bi = &rq->q->limits.integrity; + u64 ref = blk_rq_pos(rq) >> (bi->interval_exp - SECTOR_SHIFT); + unsigned intervals = nr_bytes >> bi->interval_exp; + struct bio *bio; + + if (!(bi->flags & BLK_INTEGRITY_REF_TAG)) + return; + + __rq_for_each_bio(bio, rq) { + __blk_reftag_remap(bio, bi, &intervals, &ref, prep); + if (!intervals) + break; + } +} + +void blk_integrity_prepare(struct request *rq) +{ + blk_integrity_remap(rq, blk_rq_bytes(rq), true); +} + +void blk_integrity_complete(struct request *rq, unsigned int nr_bytes) +{ + blk_integrity_remap(rq, nr_bytes, false); +} |