// SPDX-License-Identifier: GPL-2.0
/*
* blk-integrity.c - Block layer data integrity extensions
*
* Copyright (C) 2007, 2008 Oracle Corporation
* Written by: Martin K. Petersen <[email protected]>
*/
#include <linux/blk-integrity.h>
#include <linux/backing-dev.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/scatterlist.h>
#include <linux/export.h>
#include <linux/slab.h>
#include "blk.h"
/**
* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
* @q: request queue
* @bio: bio with integrity metadata attached
*
* Description: Returns the number of elements required in a
* scatterlist corresponding to the integrity metadata in a bio.
*/
int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
{
struct bio_vec iv, ivprv = { NULL };
unsigned int segments = 0;
unsigned int seg_size = 0;
struct bvec_iter iter;
int prev = 0;
bio_for_each_integrity_vec(iv, bio, iter) {
if (prev) {
if (!biovec_phys_mergeable(q, &ivprv, &iv))
goto new_segment;
if (seg_size + iv.bv_len > queue_max_segment_size(q))
goto new_segment;
seg_size += iv.bv_len;
} else {
new_segment:
segments++;
seg_size = iv.bv_len;
}
prev = 1;
ivprv = iv;
}
return segments;
}
/**
* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
* @rq: request to map
* @sglist: target scatterlist
*
* Description: Map the integrity vectors in request into a
* scatterlist. The scatterlist must be big enough to hold all
* elements. I.e. sized using blk_rq_count_integrity_sg() or
* rq->nr_integrity_segments.
*/
int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist)
{
struct bio_vec iv, ivprv = { NULL };
struct request_queue *q = rq->q;
struct scatterlist *sg = NULL;
struct bio *bio = rq->bio;
unsigned int segments = 0;
struct bvec_iter iter;
int prev = 0;
bio_for_each_integrity_vec(iv, bio, iter) {
if (prev) {
if (!biovec_phys_mergeable(q, &ivprv, &iv))
goto new_segment;
if (sg->length + iv.bv_len > queue_max_segment_size(q))
goto new_segment;
sg->length += iv.bv_len;
} else {
new_segment:
if (!sg)
sg = sglist;
else {
sg_unmark_end(sg);
sg = sg_next(sg);
}
sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
segments++;
}
prev = 1;
ivprv = iv;
}
if (sg)
sg_mark_end(sg);
/*
* Something must have been wrong if the figured number of segment
* is bigger than number of req's physical integrity segments
*/
BUG_ON(segments > rq->nr_integrity_segments);
BUG_ON(segments > queue_max_integrity_segments(q));
return segments;
}
EXPORT_SYMBOL(blk_rq_map_integrity_sg);
int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf,
ssize_t bytes, u32 seed)
{
int ret = bio_integrity_map_user(rq->bio, ubuf, bytes, seed);
if (ret)
return ret;
rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q, rq->bio);
rq->cmd_flags |= REQ_INTEGRITY;
return 0;
}
EXPORT_SYMBOL_GPL(blk_rq_integrity_map_user);
bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
struct request *next)
{
if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
return true;
if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
return false;
if (bio_integrity(req->bio)->bip_flags !=
bio_integrity(next->bio)->bip_flags)
return false;
if (req->nr_integrity_segments + next->nr_integrity_segments >
q->limits.max_integrity_segments)
return false;
if (integrity_req_gap_back_merge(req, next->bio))
return false;
return true;
}
bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
struct bio *bio)
{
int nr_integrity_segs;
if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
return true;
if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
return false;
if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
return false;
nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
if (req->nr_integrity_segments + nr_integrity_segs >
q->limits.max_integrity_segments)
return false;
return true;
}
static inline struct blk_integrity *dev_to_bi(struct device *dev)
{
return &dev_to_disk(dev)->queue->limits.integrity;
}
const char *blk_integrity_profile_name(struct blk_integrity *bi)
{
switch (bi->csum_type) {
case BLK_INTEGRITY_CSUM_IP:
if (bi->flags & BLK_INTEGRITY_REF_TAG)
return "T10-DIF-TYPE1-IP";
return "T10-DIF-TYPE3-IP";
case BLK_INTEGRITY_CSUM_CRC:
if (bi->flags & BLK_INTEGRITY_REF_TAG)
return "T10-DIF-TYPE1-CRC";
return "T10-DIF-TYPE3-CRC";
case BLK_INTEGRITY_CSUM_CRC64:
if (bi->flags & BLK_INTEGRITY_REF_TAG)
return "EXT-DIF-TYPE1-CRC64";
return "EXT-DIF-TYPE3-CRC64";
case BLK_INTEGRITY_CSUM_NONE:
break;
}
return "nop";
}
EXPORT_SYMBOL_GPL(blk_integrity_profile_name);
static ssize_t flag_store(struct device *dev, const char *page, size_t count,
unsigned char flag)
{
struct request_queue *q = dev_to_disk(dev)->queue;
struct queue_limits lim;
unsigned long val;
int err;
err = kstrtoul(page, 10, &val);
if (err)
return err;
/* note that the flags are inverted vs the values in the sysfs files */
lim = queue_limits_start_update(q);
if (val)
lim.integrity.flags &= ~flag;
else
lim.integrity.flags |= flag;
blk_mq_freeze_queue(q);
err = queue_limits_commit_update(q, &lim);
blk_mq_unfreeze_queue(q);
if (err)
return err;
return count;
}
static ssize_t flag_show(struct device *dev, char *page, unsigned char flag)
{
struct blk_integrity *bi = dev_to_bi(dev);
return sysfs_emit(page, "%d\n", !(bi->flags & flag));
}
static ssize_t format_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct blk_integrity *bi = dev_to_bi(dev);
if (!bi->tuple_size)
return sysfs_emit(page, "none\n");
return sysfs_emit(page, "%s\n", blk_integrity_profile_name(bi));
}
static ssize_t tag_size_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct blk_integrity *bi = dev_to_bi(dev);
return sysfs_emit(page, "%u\n", bi->tag_size);
}
static ssize_t protection_interval_bytes_show(struct device *dev,
struct device_attribute *attr,
char *page)
{
struct blk_integrity *bi = dev_to_bi(dev);
return sysfs_emit(page, "%u\n",
bi->interval_exp ? 1 << bi->interval_exp : 0);
}
static ssize_t read_verify_store(struct device *dev,
struct device_attribute *attr,
const char *page, size_t count)
{
return flag_store(dev, page, count, BLK_INTEGRITY_NOVERIFY);
}
static ssize_t read_verify_show(struct device *dev,
struct device_attribute *attr, char *page)
{
return flag_show(dev, page, BLK_INTEGRITY_NOVERIFY);
}
static ssize_t write_generate_store(struct device *dev,
struct device_attribute *attr,
const char *page, size_t count)
{
return flag_store(dev, page, count, BLK_INTEGRITY_NOGENERATE);
}
static ssize_t write_generate_show(struct device *dev,
struct device_attribute *attr, char *page)
{
return flag_show(dev, page, BLK_INTEGRITY_NOGENERATE);
}
static ssize_t device_is_integrity_capable_show(struct device *dev,
struct device_attribute *attr,
char *page)
{
struct blk_integrity *bi = dev_to_bi(dev);
return sysfs_emit(page, "%u\n",
!!(bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE));
}
static DEVICE_ATTR_RO(format);
static DEVICE_ATTR_RO(tag_size);
static DEVICE_ATTR_RO(protection_interval_bytes);
static DEVICE_ATTR_RW(read_verify);
static DEVICE_ATTR_RW(write_generate);
static DEVICE_ATTR_RO(device_is_integrity_capable);
static struct attribute *integrity_attrs[] = {
&dev_attr_format.attr,
&dev_attr_tag_size.attr,
&dev_attr_protection_interval_bytes.attr,
&dev_attr_read_verify.attr,
&dev_attr_write_generate.attr,
&dev_attr_device_is_integrity_capable.attr,
NULL
};
const struct attribute_group blk_integrity_attr_group = {
.name = "integrity",
.attrs = integrity_attrs,
};
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