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linux/block/t10-pi.c
Christoph Hellwig e9f5f44ad3 block: remove the blk_integrity_profile structure 
Block layer integrity configuration is a bit complex right now, as it
indirects through operation vectors for a simple two-dimensional
configuration:

 a) the checksum type of none, ip checksum, crc, crc64
 b) the presence or absence of a reference tag

Remove the integrity profile, and instead add a separate csum_type flag
which replaces the existing ip-checksum field and a new flag that
indicates the presence of the reference tag.

This removes up to two layers of indirect calls, remove the need to
offload the no-op verification of non-PI metadata to a workqueue and
generally simplifies the code. The downside is that block/t10-pi.c now
has to be built into the kernel when CONFIG_BLK_DEV_INTEGRITY is
supported.  Given that both nvme and SCSI require t10-pi.ko, it is loaded
for all usual configurations that enabled CONFIG_BLK_DEV_INTEGRITY
already, though.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-14 10:20:06 -06:00

425 lines
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// 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"
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->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->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->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->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 blk_integrity_iter *iter,
struct blk_integrity *bi)
{
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;
}
}
blk_status_t blk_integrity_verify(struct blk_integrity_iter *iter,
struct blk_integrity *bi)
{
switch (bi->csum_type) {
case BLK_INTEGRITY_CSUM_CRC64:
return ext_pi_crc64_verify(iter, bi);
case BLK_INTEGRITY_CSUM_CRC:
case BLK_INTEGRITY_CSUM_IP:
return t10_pi_verify(iter, bi);
default:
return BLK_STS_OK;
}
}
void blk_integrity_prepare(struct request *rq)
{
struct blk_integrity *bi = &rq->q->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->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");
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