mirror of
https://github.com/torvalds/linux.git
synced 2024-11-08 21:21:47 +00:00
c8164d8931
This is useful in places that recycle the same scatterlist multiple times, and do not want to incur the cost of sg_init_table every time in hot paths. Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
453 lines
12 KiB
C
453 lines
12 KiB
C
/*
|
|
* blk-integrity.c - Block layer data integrity extensions
|
|
*
|
|
* Copyright (C) 2007, 2008 Oracle Corporation
|
|
* Written by: Martin K. Petersen <martin.petersen@oracle.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version
|
|
* 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
|
|
* USA.
|
|
*
|
|
*/
|
|
|
|
#include <linux/blkdev.h>
|
|
#include <linux/mempool.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <linux/export.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "blk.h"
|
|
|
|
static struct kmem_cache *integrity_cachep;
|
|
|
|
static const char *bi_unsupported_name = "unsupported";
|
|
|
|
/**
|
|
* 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;
|
|
unsigned int i = 0;
|
|
|
|
bio_for_each_integrity_vec(iv, bio, i) {
|
|
|
|
if (ivprv) {
|
|
if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
|
|
goto new_segment;
|
|
|
|
if (!BIOVEC_SEG_BOUNDARY(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;
|
|
}
|
|
|
|
ivprv = iv;
|
|
}
|
|
|
|
return segments;
|
|
}
|
|
EXPORT_SYMBOL(blk_rq_count_integrity_sg);
|
|
|
|
/**
|
|
* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
|
|
* @q: request queue
|
|
* @bio: bio with integrity metadata attached
|
|
* @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().
|
|
*/
|
|
int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
|
|
struct scatterlist *sglist)
|
|
{
|
|
struct bio_vec *iv, *ivprv = NULL;
|
|
struct scatterlist *sg = NULL;
|
|
unsigned int segments = 0;
|
|
unsigned int i = 0;
|
|
|
|
bio_for_each_integrity_vec(iv, bio, i) {
|
|
|
|
if (ivprv) {
|
|
if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
|
|
goto new_segment;
|
|
|
|
if (!BIOVEC_SEG_BOUNDARY(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++;
|
|
}
|
|
|
|
ivprv = iv;
|
|
}
|
|
|
|
if (sg)
|
|
sg_mark_end(sg);
|
|
|
|
return segments;
|
|
}
|
|
EXPORT_SYMBOL(blk_rq_map_integrity_sg);
|
|
|
|
/**
|
|
* blk_integrity_compare - Compare integrity profile of two disks
|
|
* @gd1: Disk to compare
|
|
* @gd2: Disk to compare
|
|
*
|
|
* Description: Meta-devices like DM and MD need to verify that all
|
|
* sub-devices use the same integrity format before advertising to
|
|
* upper layers that they can send/receive integrity metadata. This
|
|
* function can be used to check whether two gendisk devices have
|
|
* compatible integrity formats.
|
|
*/
|
|
int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
|
|
{
|
|
struct blk_integrity *b1 = gd1->integrity;
|
|
struct blk_integrity *b2 = gd2->integrity;
|
|
|
|
if (!b1 && !b2)
|
|
return 0;
|
|
|
|
if (!b1 || !b2)
|
|
return -1;
|
|
|
|
if (b1->sector_size != b2->sector_size) {
|
|
printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
|
|
gd1->disk_name, gd2->disk_name,
|
|
b1->sector_size, b2->sector_size);
|
|
return -1;
|
|
}
|
|
|
|
if (b1->tuple_size != b2->tuple_size) {
|
|
printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
|
|
gd1->disk_name, gd2->disk_name,
|
|
b1->tuple_size, b2->tuple_size);
|
|
return -1;
|
|
}
|
|
|
|
if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
|
|
printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
|
|
gd1->disk_name, gd2->disk_name,
|
|
b1->tag_size, b2->tag_size);
|
|
return -1;
|
|
}
|
|
|
|
if (strcmp(b1->name, b2->name)) {
|
|
printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
|
|
gd1->disk_name, gd2->disk_name,
|
|
b1->name, b2->name);
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(blk_integrity_compare);
|
|
|
|
int blk_integrity_merge_rq(struct request_queue *q, struct request *req,
|
|
struct request *next)
|
|
{
|
|
if (blk_integrity_rq(req) != blk_integrity_rq(next))
|
|
return -1;
|
|
|
|
if (req->nr_integrity_segments + next->nr_integrity_segments >
|
|
q->limits.max_integrity_segments)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(blk_integrity_merge_rq);
|
|
|
|
int blk_integrity_merge_bio(struct request_queue *q, struct request *req,
|
|
struct bio *bio)
|
|
{
|
|
int nr_integrity_segs;
|
|
struct bio *next = bio->bi_next;
|
|
|
|
bio->bi_next = NULL;
|
|
nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
|
|
bio->bi_next = next;
|
|
|
|
if (req->nr_integrity_segments + nr_integrity_segs >
|
|
q->limits.max_integrity_segments)
|
|
return -1;
|
|
|
|
req->nr_integrity_segments += nr_integrity_segs;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(blk_integrity_merge_bio);
|
|
|
|
struct integrity_sysfs_entry {
|
|
struct attribute attr;
|
|
ssize_t (*show)(struct blk_integrity *, char *);
|
|
ssize_t (*store)(struct blk_integrity *, const char *, size_t);
|
|
};
|
|
|
|
static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
|
|
char *page)
|
|
{
|
|
struct blk_integrity *bi =
|
|
container_of(kobj, struct blk_integrity, kobj);
|
|
struct integrity_sysfs_entry *entry =
|
|
container_of(attr, struct integrity_sysfs_entry, attr);
|
|
|
|
return entry->show(bi, page);
|
|
}
|
|
|
|
static ssize_t integrity_attr_store(struct kobject *kobj,
|
|
struct attribute *attr, const char *page,
|
|
size_t count)
|
|
{
|
|
struct blk_integrity *bi =
|
|
container_of(kobj, struct blk_integrity, kobj);
|
|
struct integrity_sysfs_entry *entry =
|
|
container_of(attr, struct integrity_sysfs_entry, attr);
|
|
ssize_t ret = 0;
|
|
|
|
if (entry->store)
|
|
ret = entry->store(bi, page, count);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
|
|
{
|
|
if (bi != NULL && bi->name != NULL)
|
|
return sprintf(page, "%s\n", bi->name);
|
|
else
|
|
return sprintf(page, "none\n");
|
|
}
|
|
|
|
static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
|
|
{
|
|
if (bi != NULL)
|
|
return sprintf(page, "%u\n", bi->tag_size);
|
|
else
|
|
return sprintf(page, "0\n");
|
|
}
|
|
|
|
static ssize_t integrity_read_store(struct blk_integrity *bi,
|
|
const char *page, size_t count)
|
|
{
|
|
char *p = (char *) page;
|
|
unsigned long val = simple_strtoul(p, &p, 10);
|
|
|
|
if (val)
|
|
bi->flags |= INTEGRITY_FLAG_READ;
|
|
else
|
|
bi->flags &= ~INTEGRITY_FLAG_READ;
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
|
|
{
|
|
return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_READ) != 0);
|
|
}
|
|
|
|
static ssize_t integrity_write_store(struct blk_integrity *bi,
|
|
const char *page, size_t count)
|
|
{
|
|
char *p = (char *) page;
|
|
unsigned long val = simple_strtoul(p, &p, 10);
|
|
|
|
if (val)
|
|
bi->flags |= INTEGRITY_FLAG_WRITE;
|
|
else
|
|
bi->flags &= ~INTEGRITY_FLAG_WRITE;
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
|
|
{
|
|
return sprintf(page, "%d\n", (bi->flags & INTEGRITY_FLAG_WRITE) != 0);
|
|
}
|
|
|
|
static struct integrity_sysfs_entry integrity_format_entry = {
|
|
.attr = { .name = "format", .mode = S_IRUGO },
|
|
.show = integrity_format_show,
|
|
};
|
|
|
|
static struct integrity_sysfs_entry integrity_tag_size_entry = {
|
|
.attr = { .name = "tag_size", .mode = S_IRUGO },
|
|
.show = integrity_tag_size_show,
|
|
};
|
|
|
|
static struct integrity_sysfs_entry integrity_read_entry = {
|
|
.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
|
|
.show = integrity_read_show,
|
|
.store = integrity_read_store,
|
|
};
|
|
|
|
static struct integrity_sysfs_entry integrity_write_entry = {
|
|
.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
|
|
.show = integrity_write_show,
|
|
.store = integrity_write_store,
|
|
};
|
|
|
|
static struct attribute *integrity_attrs[] = {
|
|
&integrity_format_entry.attr,
|
|
&integrity_tag_size_entry.attr,
|
|
&integrity_read_entry.attr,
|
|
&integrity_write_entry.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct sysfs_ops integrity_ops = {
|
|
.show = &integrity_attr_show,
|
|
.store = &integrity_attr_store,
|
|
};
|
|
|
|
static int __init blk_dev_integrity_init(void)
|
|
{
|
|
integrity_cachep = kmem_cache_create("blkdev_integrity",
|
|
sizeof(struct blk_integrity),
|
|
0, SLAB_PANIC, NULL);
|
|
return 0;
|
|
}
|
|
subsys_initcall(blk_dev_integrity_init);
|
|
|
|
static void blk_integrity_release(struct kobject *kobj)
|
|
{
|
|
struct blk_integrity *bi =
|
|
container_of(kobj, struct blk_integrity, kobj);
|
|
|
|
kmem_cache_free(integrity_cachep, bi);
|
|
}
|
|
|
|
static struct kobj_type integrity_ktype = {
|
|
.default_attrs = integrity_attrs,
|
|
.sysfs_ops = &integrity_ops,
|
|
.release = blk_integrity_release,
|
|
};
|
|
|
|
bool blk_integrity_is_initialized(struct gendisk *disk)
|
|
{
|
|
struct blk_integrity *bi = blk_get_integrity(disk);
|
|
|
|
return (bi && bi->name && strcmp(bi->name, bi_unsupported_name) != 0);
|
|
}
|
|
EXPORT_SYMBOL(blk_integrity_is_initialized);
|
|
|
|
/**
|
|
* blk_integrity_register - Register a gendisk as being integrity-capable
|
|
* @disk: struct gendisk pointer to make integrity-aware
|
|
* @template: optional integrity profile to register
|
|
*
|
|
* Description: When a device needs to advertise itself as being able
|
|
* to send/receive integrity metadata it must use this function to
|
|
* register the capability with the block layer. The template is a
|
|
* blk_integrity struct with values appropriate for the underlying
|
|
* hardware. If template is NULL the new profile is allocated but
|
|
* not filled out. See Documentation/block/data-integrity.txt.
|
|
*/
|
|
int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
|
|
{
|
|
struct blk_integrity *bi;
|
|
|
|
BUG_ON(disk == NULL);
|
|
|
|
if (disk->integrity == NULL) {
|
|
bi = kmem_cache_alloc(integrity_cachep,
|
|
GFP_KERNEL | __GFP_ZERO);
|
|
if (!bi)
|
|
return -1;
|
|
|
|
if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
|
|
&disk_to_dev(disk)->kobj,
|
|
"%s", "integrity")) {
|
|
kmem_cache_free(integrity_cachep, bi);
|
|
return -1;
|
|
}
|
|
|
|
kobject_uevent(&bi->kobj, KOBJ_ADD);
|
|
|
|
bi->flags |= INTEGRITY_FLAG_READ | INTEGRITY_FLAG_WRITE;
|
|
bi->sector_size = queue_logical_block_size(disk->queue);
|
|
disk->integrity = bi;
|
|
} else
|
|
bi = disk->integrity;
|
|
|
|
/* Use the provided profile as template */
|
|
if (template != NULL) {
|
|
bi->name = template->name;
|
|
bi->generate_fn = template->generate_fn;
|
|
bi->verify_fn = template->verify_fn;
|
|
bi->tuple_size = template->tuple_size;
|
|
bi->set_tag_fn = template->set_tag_fn;
|
|
bi->get_tag_fn = template->get_tag_fn;
|
|
bi->tag_size = template->tag_size;
|
|
} else
|
|
bi->name = bi_unsupported_name;
|
|
|
|
disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(blk_integrity_register);
|
|
|
|
/**
|
|
* blk_integrity_unregister - Remove block integrity profile
|
|
* @disk: disk whose integrity profile to deallocate
|
|
*
|
|
* Description: This function frees all memory used by the block
|
|
* integrity profile. To be called at device teardown.
|
|
*/
|
|
void blk_integrity_unregister(struct gendisk *disk)
|
|
{
|
|
struct blk_integrity *bi;
|
|
|
|
if (!disk || !disk->integrity)
|
|
return;
|
|
|
|
disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;
|
|
|
|
bi = disk->integrity;
|
|
|
|
kobject_uevent(&bi->kobj, KOBJ_REMOVE);
|
|
kobject_del(&bi->kobj);
|
|
kobject_put(&bi->kobj);
|
|
disk->integrity = NULL;
|
|
}
|
|
EXPORT_SYMBOL(blk_integrity_unregister);
|