| // 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 <linux/module.h> |
| #include <net/checksum.h> |
| #include <asm/unaligned.h> |
| #include "blk.h" |
| |
| struct blk_integrity_iter { |
| void *prot_buf; |
| void *data_buf; |
| sector_t seed; |
| unsigned int data_size; |
| unsigned short interval; |
| const char *disk_name; |
| }; |
| |
| static __be16 t10_pi_csum(__be16 csum, void *data, unsigned int len, |
| unsigned char csum_type) |
| { |
| if (csum_type == BLK_INTEGRITY_CSUM_IP) |
| return (__force __be16)ip_compute_csum(data, len); |
| return cpu_to_be16(crc_t10dif_update(be16_to_cpu(csum), data, len)); |
| } |
| |
| /* |
| * Type 1 and Type 2 protection use the same format: 16 bit guard tag, |
| * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref |
| * tag. |
| */ |
| static void t10_pi_generate(struct blk_integrity_iter *iter, |
| struct blk_integrity *bi) |
| { |
| u8 offset = bi->pi_offset; |
| unsigned int i; |
| |
| for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
| struct t10_pi_tuple *pi = iter->prot_buf + offset; |
| |
| pi->guard_tag = t10_pi_csum(0, iter->data_buf, iter->interval, |
| bi->csum_type); |
| if (offset) |
| pi->guard_tag = t10_pi_csum(pi->guard_tag, |
| iter->prot_buf, offset, bi->csum_type); |
| pi->app_tag = 0; |
| |
| if (bi->flags & BLK_INTEGRITY_REF_TAG) |
| pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed)); |
| else |
| pi->ref_tag = 0; |
| |
| iter->data_buf += iter->interval; |
| iter->prot_buf += bi->tuple_size; |
| iter->seed++; |
| } |
| } |
| |
| static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter, |
| struct blk_integrity *bi) |
| { |
| u8 offset = bi->pi_offset; |
| unsigned int i; |
| |
| for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
| struct t10_pi_tuple *pi = iter->prot_buf + offset; |
| __be16 csum; |
| |
| if (bi->flags & BLK_INTEGRITY_REF_TAG) { |
| if (pi->app_tag == T10_PI_APP_ESCAPE) |
| goto next; |
| |
| if (be32_to_cpu(pi->ref_tag) != |
| lower_32_bits(iter->seed)) { |
| pr_err("%s: ref tag error at location %llu " \ |
| "(rcvd %u)\n", iter->disk_name, |
| (unsigned long long) |
| iter->seed, be32_to_cpu(pi->ref_tag)); |
| return BLK_STS_PROTECTION; |
| } |
| } else { |
| if (pi->app_tag == T10_PI_APP_ESCAPE && |
| pi->ref_tag == T10_PI_REF_ESCAPE) |
| goto next; |
| } |
| |
| csum = t10_pi_csum(0, iter->data_buf, iter->interval, |
| bi->csum_type); |
| if (offset) |
| csum = t10_pi_csum(csum, iter->prot_buf, offset, |
| bi->csum_type); |
| |
| if (pi->guard_tag != csum) { |
| pr_err("%s: guard tag error at sector %llu " \ |
| "(rcvd %04x, want %04x)\n", iter->disk_name, |
| (unsigned long long)iter->seed, |
| be16_to_cpu(pi->guard_tag), be16_to_cpu(csum)); |
| return BLK_STS_PROTECTION; |
| } |
| |
| next: |
| iter->data_buf += iter->interval; |
| iter->prot_buf += bi->tuple_size; |
| iter->seed++; |
| } |
| |
| return BLK_STS_OK; |
| } |
| |
| /** |
| * t10_pi_type1_prepare - prepare PI prior submitting request to device |
| * @rq: request with PI that should be prepared |
| * |
| * For Type 1/Type 2, the virtual start sector is the one that was |
| * originally submitted by the block layer for the ref_tag usage. Due to |
| * partitioning, MD/DM cloning, etc. the actual physical start sector is |
| * likely to be different. Remap protection information to match the |
| * physical LBA. |
| */ |
| static void t10_pi_type1_prepare(struct request *rq) |
| { |
| struct blk_integrity *bi = &rq->q->limits.integrity; |
| const int tuple_sz = bi->tuple_size; |
| u32 ref_tag = t10_pi_ref_tag(rq); |
| u8 offset = bi->pi_offset; |
| struct bio *bio; |
| |
| __rq_for_each_bio(bio, rq) { |
| struct bio_integrity_payload *bip = bio_integrity(bio); |
| u32 virt = bip_get_seed(bip) & 0xffffffff; |
| struct bio_vec iv; |
| struct bvec_iter iter; |
| |
| /* Already remapped? */ |
| if (bip->bip_flags & BIP_MAPPED_INTEGRITY) |
| break; |
| |
| bip_for_each_vec(iv, bip, iter) { |
| unsigned int j; |
| void *p; |
| |
| p = bvec_kmap_local(&iv); |
| for (j = 0; j < iv.bv_len; j += tuple_sz) { |
| struct t10_pi_tuple *pi = p + offset; |
| |
| if (be32_to_cpu(pi->ref_tag) == virt) |
| pi->ref_tag = cpu_to_be32(ref_tag); |
| virt++; |
| ref_tag++; |
| p += tuple_sz; |
| } |
| kunmap_local(p); |
| } |
| |
| bip->bip_flags |= BIP_MAPPED_INTEGRITY; |
| } |
| } |
| |
| /** |
| * t10_pi_type1_complete - prepare PI prior returning request to the blk layer |
| * @rq: request with PI that should be prepared |
| * @nr_bytes: total bytes to prepare |
| * |
| * For Type 1/Type 2, the virtual start sector is the one that was |
| * originally submitted by the block layer for the ref_tag usage. Due to |
| * partitioning, MD/DM cloning, etc. the actual physical start sector is |
| * likely to be different. Since the physical start sector was submitted |
| * to the device, we should remap it back to virtual values expected by the |
| * block layer. |
| */ |
| static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes) |
| { |
| struct blk_integrity *bi = &rq->q->limits.integrity; |
| unsigned intervals = nr_bytes >> bi->interval_exp; |
| const int tuple_sz = bi->tuple_size; |
| u32 ref_tag = t10_pi_ref_tag(rq); |
| u8 offset = bi->pi_offset; |
| struct bio *bio; |
| |
| __rq_for_each_bio(bio, rq) { |
| struct bio_integrity_payload *bip = bio_integrity(bio); |
| u32 virt = bip_get_seed(bip) & 0xffffffff; |
| struct bio_vec iv; |
| struct bvec_iter iter; |
| |
| bip_for_each_vec(iv, bip, iter) { |
| unsigned int j; |
| void *p; |
| |
| p = bvec_kmap_local(&iv); |
| for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) { |
| struct t10_pi_tuple *pi = p + offset; |
| |
| if (be32_to_cpu(pi->ref_tag) == ref_tag) |
| pi->ref_tag = cpu_to_be32(virt); |
| virt++; |
| ref_tag++; |
| intervals--; |
| p += tuple_sz; |
| } |
| kunmap_local(p); |
| } |
| } |
| } |
| |
| static __be64 ext_pi_crc64(u64 crc, void *data, unsigned int len) |
| { |
| return cpu_to_be64(crc64_rocksoft_update(crc, data, len)); |
| } |
| |
| static void ext_pi_crc64_generate(struct blk_integrity_iter *iter, |
| struct blk_integrity *bi) |
| { |
| u8 offset = bi->pi_offset; |
| unsigned int i; |
| |
| for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
| struct crc64_pi_tuple *pi = iter->prot_buf + offset; |
| |
| pi->guard_tag = ext_pi_crc64(0, iter->data_buf, iter->interval); |
| if (offset) |
| pi->guard_tag = ext_pi_crc64(be64_to_cpu(pi->guard_tag), |
| iter->prot_buf, offset); |
| pi->app_tag = 0; |
| |
| if (bi->flags & BLK_INTEGRITY_REF_TAG) |
| put_unaligned_be48(iter->seed, pi->ref_tag); |
| else |
| put_unaligned_be48(0ULL, pi->ref_tag); |
| |
| iter->data_buf += iter->interval; |
| iter->prot_buf += bi->tuple_size; |
| iter->seed++; |
| } |
| } |
| |
| static bool ext_pi_ref_escape(u8 *ref_tag) |
| { |
| static u8 ref_escape[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; |
| |
| return memcmp(ref_tag, ref_escape, sizeof(ref_escape)) == 0; |
| } |
| |
| static blk_status_t ext_pi_crc64_verify(struct blk_integrity_iter *iter, |
| struct blk_integrity *bi) |
| { |
| u8 offset = bi->pi_offset; |
| unsigned int i; |
| |
| for (i = 0; i < iter->data_size; i += iter->interval) { |
| struct crc64_pi_tuple *pi = iter->prot_buf + offset; |
| u64 ref, seed; |
| __be64 csum; |
| |
| if (bi->flags & BLK_INTEGRITY_REF_TAG) { |
| if (pi->app_tag == T10_PI_APP_ESCAPE) |
| goto next; |
| |
| ref = get_unaligned_be48(pi->ref_tag); |
| seed = lower_48_bits(iter->seed); |
| if (ref != seed) { |
| pr_err("%s: ref tag error at location %llu (rcvd %llu)\n", |
| iter->disk_name, seed, ref); |
| return BLK_STS_PROTECTION; |
| } |
| } else { |
| if (pi->app_tag == T10_PI_APP_ESCAPE && |
| ext_pi_ref_escape(pi->ref_tag)) |
| goto next; |
| } |
| |
| csum = ext_pi_crc64(0, iter->data_buf, iter->interval); |
| if (offset) |
| csum = ext_pi_crc64(be64_to_cpu(csum), iter->prot_buf, |
| offset); |
| |
| if (pi->guard_tag != csum) { |
| pr_err("%s: guard tag error at sector %llu " \ |
| "(rcvd %016llx, want %016llx)\n", |
| iter->disk_name, (unsigned long long)iter->seed, |
| be64_to_cpu(pi->guard_tag), be64_to_cpu(csum)); |
| return BLK_STS_PROTECTION; |
| } |
| |
| next: |
| iter->data_buf += iter->interval; |
| iter->prot_buf += bi->tuple_size; |
| iter->seed++; |
| } |
| |
| return BLK_STS_OK; |
| } |
| |
| static void ext_pi_type1_prepare(struct request *rq) |
| { |
| struct blk_integrity *bi = &rq->q->limits.integrity; |
| const int tuple_sz = bi->tuple_size; |
| u64 ref_tag = ext_pi_ref_tag(rq); |
| u8 offset = bi->pi_offset; |
| struct bio *bio; |
| |
| __rq_for_each_bio(bio, rq) { |
| struct bio_integrity_payload *bip = bio_integrity(bio); |
| u64 virt = lower_48_bits(bip_get_seed(bip)); |
| struct bio_vec iv; |
| struct bvec_iter iter; |
| |
| /* Already remapped? */ |
| if (bip->bip_flags & BIP_MAPPED_INTEGRITY) |
| break; |
| |
| bip_for_each_vec(iv, bip, iter) { |
| unsigned int j; |
| void *p; |
| |
| p = bvec_kmap_local(&iv); |
| for (j = 0; j < iv.bv_len; j += tuple_sz) { |
| struct crc64_pi_tuple *pi = p + offset; |
| u64 ref = get_unaligned_be48(pi->ref_tag); |
| |
| if (ref == virt) |
| put_unaligned_be48(ref_tag, pi->ref_tag); |
| virt++; |
| ref_tag++; |
| p += tuple_sz; |
| } |
| kunmap_local(p); |
| } |
| |
| bip->bip_flags |= BIP_MAPPED_INTEGRITY; |
| } |
| } |
| |
| static void ext_pi_type1_complete(struct request *rq, unsigned int nr_bytes) |
| { |
| struct blk_integrity *bi = &rq->q->limits.integrity; |
| unsigned intervals = nr_bytes >> bi->interval_exp; |
| const int tuple_sz = bi->tuple_size; |
| u64 ref_tag = ext_pi_ref_tag(rq); |
| u8 offset = bi->pi_offset; |
| struct bio *bio; |
| |
| __rq_for_each_bio(bio, rq) { |
| struct bio_integrity_payload *bip = bio_integrity(bio); |
| u64 virt = lower_48_bits(bip_get_seed(bip)); |
| struct bio_vec iv; |
| struct bvec_iter iter; |
| |
| bip_for_each_vec(iv, bip, iter) { |
| unsigned int j; |
| void *p; |
| |
| p = bvec_kmap_local(&iv); |
| for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) { |
| struct crc64_pi_tuple *pi = p + offset; |
| u64 ref = get_unaligned_be48(pi->ref_tag); |
| |
| if (ref == ref_tag) |
| put_unaligned_be48(virt, pi->ref_tag); |
| virt++; |
| ref_tag++; |
| intervals--; |
| p += tuple_sz; |
| } |
| kunmap_local(p); |
| } |
| } |
| } |
| |
| void blk_integrity_generate(struct bio *bio) |
| { |
| 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; |
| struct bvec_iter bviter; |
| struct bio_vec bv; |
| |
| iter.disk_name = bio->bi_bdev->bd_disk->disk_name; |
| iter.interval = 1 << bi->interval_exp; |
| iter.seed = bio->bi_iter.bi_sector; |
| iter.prot_buf = bvec_virt(bip->bip_vec); |
| bio_for_each_segment(bv, bio, bviter) { |
| void *kaddr = bvec_kmap_local(&bv); |
| |
| iter.data_buf = kaddr; |
| iter.data_size = bv.bv_len; |
| switch (bi->csum_type) { |
| case BLK_INTEGRITY_CSUM_CRC64: |
| ext_pi_crc64_generate(&iter, bi); |
| break; |
| case BLK_INTEGRITY_CSUM_CRC: |
| case BLK_INTEGRITY_CSUM_IP: |
| t10_pi_generate(&iter, bi); |
| break; |
| default: |
| break; |
| } |
| kunmap_local(kaddr); |
| } |
| } |
| |
| void blk_integrity_verify(struct bio *bio) |
| { |
| 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; |
| struct bvec_iter bviter; |
| struct bio_vec bv; |
| |
| /* |
| * At the moment verify is called bi_iter has been advanced during split |
| * and completion, so use the copy created during submission here. |
| */ |
| iter.disk_name = bio->bi_bdev->bd_disk->disk_name; |
| iter.interval = 1 << bi->interval_exp; |
| iter.seed = bip->bio_iter.bi_sector; |
| iter.prot_buf = bvec_virt(bip->bip_vec); |
| __bio_for_each_segment(bv, bio, bviter, bip->bio_iter) { |
| void *kaddr = bvec_kmap_local(&bv); |
| blk_status_t ret = BLK_STS_OK; |
| |
| iter.data_buf = kaddr; |
| iter.data_size = bv.bv_len; |
| switch (bi->csum_type) { |
| case BLK_INTEGRITY_CSUM_CRC64: |
| ret = ext_pi_crc64_verify(&iter, bi); |
| break; |
| case BLK_INTEGRITY_CSUM_CRC: |
| case BLK_INTEGRITY_CSUM_IP: |
| ret = t10_pi_verify(&iter, bi); |
| break; |
| default: |
| break; |
| } |
| kunmap_local(kaddr); |
| |
| if (ret) { |
| bio->bi_status = ret; |
| return; |
| } |
| } |
| } |
| |
| void blk_integrity_prepare(struct request *rq) |
| { |
| struct blk_integrity *bi = &rq->q->limits.integrity; |
| |
| if (!(bi->flags & BLK_INTEGRITY_REF_TAG)) |
| return; |
| |
| if (bi->csum_type == BLK_INTEGRITY_CSUM_CRC64) |
| ext_pi_type1_prepare(rq); |
| else |
| t10_pi_type1_prepare(rq); |
| } |
| |
| void blk_integrity_complete(struct request *rq, unsigned int nr_bytes) |
| { |
| struct blk_integrity *bi = &rq->q->limits.integrity; |
| |
| if (!(bi->flags & BLK_INTEGRITY_REF_TAG)) |
| return; |
| |
| if (bi->csum_type == BLK_INTEGRITY_CSUM_CRC64) |
| ext_pi_type1_complete(rq, nr_bytes); |
| else |
| t10_pi_type1_complete(rq, nr_bytes); |
| } |
| |
| MODULE_DESCRIPTION("T10 Protection Information module"); |
| MODULE_LICENSE("GPL"); |