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block: Block layer data integrity support

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Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.

This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.

See Documentation/block/data-integrity.txt for more information.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Martin K. Petersen 2008-06-30 20:04:41 +02:00 committed by Jens Axboe
parent 51d654e1d8
commit 7ba1ba12ee
13 changed files with 1355 additions and 7 deletions
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12
block/Kconfig
View file

@ -81,6 +81,18 @@ config BLK_DEV_BSG
If unsure, say N.
config BLK_DEV_INTEGRITY
bool "Block layer data integrity support"
---help---
Some storage devices allow extra information to be
stored/retrieved to help protect the data. The block layer
data integrity option provides hooks which can be used by
filesystems to ensure better data integrity.
Say yes here if you have a storage device that provides the
T10/SCSI Data Integrity Field or the T13/ATA External Path
Protection. If in doubt, say N.
endif # BLOCK
config BLOCK_COMPAT

1
block/Makefile
View file

@ -14,3 +14,4 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o

7
block/blk-core.c
View file

@ -143,6 +143,10 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
bio->bi_size -= nbytes;
bio->bi_sector += (nbytes >> 9);
if (bio_integrity(bio))
bio_integrity_advance(bio, nbytes);
if (bio->bi_size == 0)
bio_endio(bio, error);
} else {
@ -1381,6 +1385,9 @@ end_io:
*/
blk_partition_remap(bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio))
goto end_io;
if (old_sector != -1)
blk_add_trace_remap(q, bio, old_dev, bio->bi_sector,
old_sector);

382
block/blk-integrity.c Normal file
View file

@ -0,0 +1,382 @@
/*
* 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 "blk.h"
static struct kmem_cache *integrity_cachep;
/**
* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
* @rq: request with integrity metadata attached
*
* Description: Returns the number of elements required in a
* scatterlist corresponding to the integrity metadata in a request.
*/
int blk_rq_count_integrity_sg(struct request *rq)
{
struct bio_vec *iv, *ivprv;
struct req_iterator iter;
unsigned int segments;
ivprv = NULL;
segments = 0;
rq_for_each_integrity_segment(iv, rq, iter) {
if (!ivprv || !BIOVEC_PHYS_MERGEABLE(ivprv, iv))
segments++;
ivprv = iv;
}
return segments;
}
EXPORT_SYMBOL(blk_rq_count_integrity_sg);
/**
* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
* @rq: request 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 *rq, struct scatterlist *sglist)
{
struct bio_vec *iv, *ivprv;
struct req_iterator iter;
struct scatterlist *sg;
unsigned int segments;
ivprv = NULL;
sg = NULL;
segments = 0;
rq_for_each_integrity_segment(iv, rq, iter) {
if (ivprv) {
if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv))
goto new_segment;
sg->length += iv->bv_len;
} else {
new_segment:
if (!sg)
sg = sglist;
else {
sg->page_link &= ~0x02;
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 block devices
* @b1: Device to compare
* @b2: Device 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 block devices have
* compatible integrity formats.
*/
int blk_integrity_compare(struct block_device *bd1, struct block_device *bd2)
{
struct blk_integrity *b1 = bd1->bd_disk->integrity;
struct blk_integrity *b2 = bd2->bd_disk->integrity;
BUG_ON(bd1->bd_disk == NULL);
BUG_ON(bd2->bd_disk == NULL);
if (!b1 || !b2)
return 0;
if (b1->sector_size != b2->sector_size) {
printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
bd1->bd_disk->disk_name, bd2->bd_disk->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__,
bd1->bd_disk->disk_name, bd2->bd_disk->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__,
bd1->bd_disk->disk_name, bd2->bd_disk->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__,
bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
b1->name, b2->name);
return -1;
}
return 0;
}
EXPORT_SYMBOL(blk_integrity_compare);
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)
set_bit(INTEGRITY_FLAG_READ, &bi->flags);
else
clear_bit(INTEGRITY_FLAG_READ, &bi->flags);
return count;
}
static ssize_t integrity_read_show(struct blk_integrity *bi, char *page)
{
return sprintf(page, "%d\n",
test_bit(INTEGRITY_FLAG_READ, &bi->flags) ? 1 : 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)
set_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
else
clear_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
return count;
}
static ssize_t integrity_write_show(struct blk_integrity *bi, char *page)
{
return sprintf(page, "%d\n",
test_bit(INTEGRITY_FLAG_WRITE, &bi->flags) ? 1 : 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 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,
};
/**
* blk_integrity_register - Register a gendisk as being integrity-capable
* @disk: struct gendisk pointer to make integrity-aware
* @template: integrity profile
*
* 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. 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);
BUG_ON(template == 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->dev.kobj, "%s", "integrity")) {
kmem_cache_free(integrity_cachep, bi);
return -1;
}
kobject_uevent(&bi->kobj, KOBJ_ADD);
set_bit(INTEGRITY_FLAG_READ, &bi->flags);
set_bit(INTEGRITY_FLAG_WRITE, &bi->flags);
bi->sector_size = disk->queue->hardsect_size;
disk->integrity = bi;
} else
bi = disk->integrity;
/* Use the provided profile as template */
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;
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;
bi = disk->integrity;
kobject_uevent(&bi->kobj, KOBJ_REMOVE);
kobject_del(&bi->kobj);
kobject_put(&disk->dev.kobj);
kmem_cache_free(integrity_cachep, bi);
}
EXPORT_SYMBOL(blk_integrity_unregister);

3
block/blk-merge.c
View file

@ -441,6 +441,9 @@ static int attempt_merge(struct request_queue *q, struct request *req,
|| next->special)
return 0;
if (blk_integrity_rq(req) != blk_integrity_rq(next))
return 0;
/*
* If we are allowed to merge, then append bio list
* from next to rq and release next. merge_requests_fn

8
block/blk.h
View file

@ -51,4 +51,12 @@ static inline int queue_congestion_off_threshold(struct request_queue *q)
return q->nr_congestion_off;
}
#if defined(CONFIG_BLK_DEV_INTEGRITY)
#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
__rq_for_each_bio(_iter.bio, _rq) \
bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
#endif /* BLK_DEV_INTEGRITY */
#endif

6
block/elevator.c
View file

@ -86,6 +86,12 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
return 0;
/*
* only merge integrity protected bio into ditto rq
*/
if (bio_integrity(bio) != blk_integrity_rq(rq))
return 0;
if (!elv_iosched_allow_merge(rq, bio))
return 0;

1
fs/Makefile
View file

@ -19,6 +19,7 @@ else
obj-y += no-block.o
endif
obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
obj-$(CONFIG_INOTIFY) += inotify.o
obj-$(CONFIG_INOTIFY_USER) += inotify_user.o
obj-$(CONFIG_EPOLL) += eventpoll.o

708
fs/bio-integrity.c Normal file
View file

@ -0,0 +1,708 @@
/*
* bio-integrity.c - bio 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/workqueue.h>
static struct kmem_cache *bio_integrity_slab __read_mostly;
static struct workqueue_struct *kintegrityd_wq;
/**
* bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
* @bio: bio to attach integrity metadata to
* @gfp_mask: Memory allocation mask
* @nr_vecs: Number of integrity metadata scatter-gather elements
* @bs: bio_set to allocate from
*
* Description: This function prepares a bio for attaching integrity
* metadata. nr_vecs specifies the maximum number of pages containing
* integrity metadata that can be attached.
*/
struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio, gfp_t gfp_mask, unsigned int nr_vecs, struct bio_set *bs)
{
struct bio_integrity_payload *bip;
struct bio_vec *iv;
unsigned long idx;
BUG_ON(bio == NULL);
bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
if (unlikely(bip == NULL)) {
printk(KERN_ERR "%s: could not alloc bip\n", __func__);
return NULL;
}
memset(bip, 0, sizeof(*bip));
iv = bvec_alloc_bs(gfp_mask, nr_vecs, &idx, bs);
if (unlikely(iv == NULL)) {
printk(KERN_ERR "%s: could not alloc bip_vec\n", __func__);
mempool_free(bip, bs->bio_integrity_pool);
return NULL;
}
bip->bip_pool = idx;
bip->bip_vec = iv;
bip->bip_bio = bio;
bio->bi_integrity = bip;
return bip;
}
EXPORT_SYMBOL(bio_integrity_alloc_bioset);
/**
* bio_integrity_alloc - Allocate integrity payload and attach it to bio
* @bio: bio to attach integrity metadata to
* @gfp_mask: Memory allocation mask
* @nr_vecs: Number of integrity metadata scatter-gather elements
*
* Description: This function prepares a bio for attaching integrity
* metadata. nr_vecs specifies the maximum number of pages containing
* integrity metadata that can be attached.
*/
struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, gfp_t gfp_mask, unsigned int nr_vecs)
{
return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
}
EXPORT_SYMBOL(bio_integrity_alloc);
/**
* bio_integrity_free - Free bio integrity payload
* @bio: bio containing bip to be freed
* @bs: bio_set this bio was allocated from
*
* Description: Used to free the integrity portion of a bio. Usually
* called from bio_free().
*/
void bio_integrity_free(struct bio *bio, struct bio_set *bs)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
BUG_ON(bip == NULL);
/* A cloned bio doesn't own the integrity metadata */
if (!bio_flagged(bio, BIO_CLONED) && bip->bip_buf != NULL)
kfree(bip->bip_buf);
mempool_free(bip->bip_vec, bs->bvec_pools[bip->bip_pool]);
mempool_free(bip, bs->bio_integrity_pool);
bio->bi_integrity = NULL;
}
EXPORT_SYMBOL(bio_integrity_free);
/**
* bio_integrity_add_page - Attach integrity metadata
* @bio: bio to update
* @page: page containing integrity metadata
* @len: number of bytes of integrity metadata in page
* @offset: start offset within page
*
* Description: Attach a page containing integrity metadata to bio.
*/
int bio_integrity_add_page(struct bio *bio, struct page *page,
unsigned int len, unsigned int offset)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
struct bio_vec *iv;
if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_pool)) {
printk(KERN_ERR "%s: bip_vec full\n", __func__);
return 0;
}
iv = bip_vec_idx(bip, bip->bip_vcnt);
BUG_ON(iv == NULL);
BUG_ON(iv->bv_page != NULL);
iv->bv_page = page;
iv->bv_len = len;
iv->bv_offset = offset;
bip->bip_vcnt++;
return len;
}
EXPORT_SYMBOL(bio_integrity_add_page);
/**
* bio_integrity_enabled - Check whether integrity can be passed
* @bio: bio to check
*
* Description: Determines whether bio_integrity_prep() can be called
* on this bio or not. bio data direction and target device must be
* set prior to calling. The functions honors the write_generate and
* read_verify flags in sysfs.
*/
int bio_integrity_enabled(struct bio *bio)
{
/* Already protected? */
if (bio_integrity(bio))
return 0;
return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
}
EXPORT_SYMBOL(bio_integrity_enabled);
/**
* bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
* @bi: blk_integrity profile for device
* @sectors: Number of 512 sectors to convert
*
* Description: The block layer calculates everything in 512 byte
* sectors but integrity metadata is done in terms of the hardware
* sector size of the storage device. Convert the block layer sectors
* to physical sectors.
*/
static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi, unsigned int sectors)
{
/* At this point there are only 512b or 4096b DIF/EPP devices */
if (bi->sector_size == 4096)
return sectors >>= 3;
return sectors;
}
/**
* bio_integrity_tag_size - Retrieve integrity tag space
* @bio: bio to inspect
*
* Description: Returns the maximum number of tag bytes that can be
* attached to this bio. Filesystems can use this to determine how
* much metadata to attach to an I/O.
*/
unsigned int bio_integrity_tag_size(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
BUG_ON(bio->bi_size == 0);
return bi->tag_size * (bio->bi_size / bi->sector_size);
}
EXPORT_SYMBOL(bio_integrity_tag_size);
int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip->bip_buf == NULL);
if (bi->tag_size == 0)
return -1;
nr_sectors = bio_integrity_hw_sectors(bi, DIV_ROUND_UP(len, bi->tag_size));
if (nr_sectors * bi->tuple_size > bip->bip_size) {
printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
__func__, nr_sectors * bi->tuple_size, bip->bip_size);
return -1;
}
if (set)
bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
else
bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
return 0;
}
/**
* bio_integrity_set_tag - Attach a tag buffer to a bio
* @bio: bio to attach buffer to
* @tag_buf: Pointer to a buffer containing tag data
* @len: Length of the included buffer
*
* Description: Use this function to tag a bio by leveraging the extra
* space provided by devices formatted with integrity protection. The
* size of the integrity buffer must be <= to the size reported by
* bio_integrity_tag_size().
*/
int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
{
BUG_ON(bio_data_dir(bio) != WRITE);
return bio_integrity_tag(bio, tag_buf, len, 1);
}
EXPORT_SYMBOL(bio_integrity_set_tag);
/**
* bio_integrity_get_tag - Retrieve a tag buffer from a bio
* @bio: bio to retrieve buffer from
* @tag_buf: Pointer to a buffer for the tag data
* @len: Length of the target buffer
*
* Description: Use this function to retrieve the tag buffer from a
* completed I/O. The size of the integrity buffer must be <= to the
* size reported by bio_integrity_tag_size().
*/
int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
{
BUG_ON(bio_data_dir(bio) != READ);
return bio_integrity_tag(bio, tag_buf, len, 0);
}
EXPORT_SYMBOL(bio_integrity_get_tag);
/**
* bio_integrity_generate - Generate integrity metadata for a bio
* @bio: bio to generate integrity metadata for
*
* Description: Generates integrity metadata for a bio by calling the
* block device's generation callback function. The bio must have a
* bip attached with enough room to accommodate the generated
* integrity metadata.
*/
static void bio_integrity_generate(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
struct blk_integrity_exchg bix;
struct bio_vec *bv;
sector_t sector = bio->bi_sector;
unsigned int i, sectors, total;
void *prot_buf = bio->bi_integrity->bip_buf;
total = 0;
bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
bix.sector_size = bi->sector_size;
bio_for_each_segment(bv, bio, i) {
void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
bix.data_buf = kaddr + bv->bv_offset;
bix.data_size = bv->bv_len;
bix.prot_buf = prot_buf;
bix.sector = sector;
bi->generate_fn(&bix);
sectors = bv->bv_len / bi->sector_size;
sector += sectors;
prot_buf += sectors * bi->tuple_size;
total += sectors * bi->tuple_size;
BUG_ON(total > bio->bi_integrity->bip_size);
kunmap_atomic(kaddr, KM_USER0);
}
}
/**
* bio_integrity_prep - Prepare bio for integrity I/O
* @bio: bio to prepare
*
* Description: Allocates a buffer for integrity metadata, maps the
* pages and attaches them to a bio. The bio must have data
* direction, target device and start sector set priot to calling. In
* the WRITE case, integrity metadata will be generated using the
* block device's integrity function. In the READ case, the buffer
* will be prepared for DMA and a suitable end_io handler set up.
*/
int bio_integrity_prep(struct bio *bio)
{
struct bio_integrity_payload *bip;
struct blk_integrity *bi;
struct request_queue *q;
void *buf;
unsigned long start, end;
unsigned int len, nr_pages;
unsigned int bytes, offset, i;
unsigned int sectors;
bi = bdev_get_integrity(bio->bi_bdev);
q = bdev_get_queue(bio->bi_bdev);
BUG_ON(bi == NULL);
BUG_ON(bio_integrity(bio));
sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
/* Allocate kernel buffer for protection data */
len = sectors * blk_integrity_tuple_size(bi);
buf = kmalloc(len, GFP_NOIO | __GFP_NOFAIL | q->bounce_gfp);
if (unlikely(buf == NULL)) {
printk(KERN_ERR "could not allocate integrity buffer\n");
return -EIO;
}
end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
start = ((unsigned long) buf) >> PAGE_SHIFT;
nr_pages = end - start;
/* Allocate bio integrity payload and integrity vectors */
bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
if (unlikely(bip == NULL)) {
printk(KERN_ERR "could not allocate data integrity bioset\n");
kfree(buf);
return -EIO;
}
bip->bip_buf = buf;
bip->bip_size = len;
bip->bip_sector = bio->bi_sector;
/* Map it */
offset = offset_in_page(buf);
for (i = 0 ; i < nr_pages ; i++) {
int ret;
bytes = PAGE_SIZE - offset;
if (len <= 0)
break;
if (bytes > len)
bytes = len;
ret = bio_integrity_add_page(bio, virt_to_page(buf),
bytes, offset);
if (ret == 0)
return 0;
if (ret < bytes)
break;
buf += bytes;
len -= bytes;
offset = 0;
}
/* Install custom I/O completion handler if read verify is enabled */
if (bio_data_dir(bio) == READ) {
bip->bip_end_io = bio->bi_end_io;
bio->bi_end_io = bio_integrity_endio;
}
/* Auto-generate integrity metadata if this is a write */
if (bio_data_dir(bio) == WRITE)
bio_integrity_generate(bio);
return 0;
}
EXPORT_SYMBOL(bio_integrity_prep);
/**
* bio_integrity_verify - Verify integrity metadata for a bio
* @bio: bio to verify
*
* Description: This function is called to verify the integrity of a
* bio. The data in the bio io_vec is compared to the integrity
* metadata returned by the HBA.
*/
static int bio_integrity_verify(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
struct blk_integrity_exchg bix;
struct bio_vec *bv;
sector_t sector = bio->bi_integrity->bip_sector;
unsigned int i, sectors, total, ret;
void *prot_buf = bio->bi_integrity->bip_buf;
ret = total = 0;
bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
bix.sector_size = bi->sector_size;
bio_for_each_segment(bv, bio, i) {
void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
bix.data_buf = kaddr + bv->bv_offset;
bix.data_size = bv->bv_len;
bix.prot_buf = prot_buf;
bix.sector = sector;
ret = bi->verify_fn(&bix);
if (ret) {
kunmap_atomic(kaddr, KM_USER0);
break;
}
sectors = bv->bv_len / bi->sector_size;
sector += sectors;
prot_buf += sectors * bi->tuple_size;
total += sectors * bi->tuple_size;
BUG_ON(total > bio->bi_integrity->bip_size);
kunmap_atomic(kaddr, KM_USER0);
}
return ret;
}
/**
* bio_integrity_verify_fn - Integrity I/O completion worker
* @work: Work struct stored in bio to be verified
*
* Description: This workqueue function is called to complete a READ
* request. The function verifies the transferred integrity metadata
* and then calls the original bio end_io function.
*/
static void bio_integrity_verify_fn(struct work_struct *work)
{
struct bio_integrity_payload *bip =
container_of(work, struct bio_integrity_payload, bip_work);
struct bio *bio = bip->bip_bio;
int error = bip->bip_error;
if (bio_integrity_verify(bio)) {
clear_bit(BIO_UPTODATE, &bio->bi_flags);
error = -EIO;
}
/* Restore original bio completion handler */
bio->bi_end_io = bip->bip_end_io;
if (bio->bi_end_io)
bio->bi_end_io(bio, error);
}
/**
* bio_integrity_endio - Integrity I/O completion function
* @bio: Protected bio
* @error: Pointer to errno
*
* Description: Completion for integrity I/O
*
* Normally I/O completion is done in interrupt context. However,
* verifying I/O integrity is a time-consuming task which must be run
* in process context. This function postpones completion
* accordingly.
*/
void bio_integrity_endio(struct bio *bio, int error)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
BUG_ON(bip->bip_bio != bio);
bip->bip_error = error;
INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
queue_work(kintegrityd_wq, &bip->bip_work);
}
EXPORT_SYMBOL(bio_integrity_endio);
/**
* bio_integrity_mark_head - Advance bip_vec skip bytes
* @bip: Integrity vector to advance
* @skip: Number of bytes to advance it
*/
void bio_integrity_mark_head(struct bio_integrity_payload *bip, unsigned int skip)
{
struct bio_vec *iv;
unsigned int i;
bip_for_each_vec(iv, bip, i) {
if (skip == 0) {
bip->bip_idx = i;
return;
} else if (skip >= iv->bv_len) {
skip -= iv->bv_len;
} else { /* skip < iv->bv_len) */
iv->bv_offset += skip;
iv->bv_len -= skip;
bip->bip_idx = i;
return;
}
}
}
/**
* bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
* @bip: Integrity vector to truncate
* @len: New length of integrity vector
*/
void bio_integrity_mark_tail(struct bio_integrity_payload *bip, unsigned int len)
{
struct bio_vec *iv;
unsigned int i;
bip_for_each_vec(iv, bip, i) {
if (len == 0) {
bip->bip_vcnt = i;
return;
} else if (len >= iv->bv_len) {
len -= iv->bv_len;
} else { /* len < iv->bv_len) */
iv->bv_len = len;
len = 0;
}
}
}
/**
* bio_integrity_advance - Advance integrity vector
* @bio: bio whose integrity vector to update
* @bytes_done: number of data bytes that have been completed
*
* Description: This function calculates how many integrity bytes the
* number of completed data bytes correspond to and advances the
* integrity vector accordingly.
*/
void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip == NULL);
BUG_ON(bi == NULL);
nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
}
EXPORT_SYMBOL(bio_integrity_advance);
/**
* bio_integrity_trim - Trim integrity vector
* @bio: bio whose integrity vector to update
* @offset: offset to first data sector
* @sectors: number of data sectors
*
* Description: Used to trim the integrity vector in a cloned bio.
* The ivec will be advanced corresponding to 'offset' data sectors
* and the length will be truncated corresponding to 'len' data
* sectors.
*/
void bio_integrity_trim(struct bio *bio, unsigned int offset, unsigned int sectors)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip == NULL);
BUG_ON(bi == NULL);
BUG_ON(!bio_flagged(bio, BIO_CLONED));
nr_sectors = bio_integrity_hw_sectors(bi, sectors);
bip->bip_sector = bip->bip_sector + offset;
bio_integrity_mark_head(bip, offset * bi->tuple_size);
bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
}
EXPORT_SYMBOL(bio_integrity_trim);
/**
* bio_integrity_split - Split integrity metadata
* @bio: Protected bio
* @bp: Resulting bio_pair
* @sectors: Offset
*
* Description: Splits an integrity page into a bio_pair.
*/
void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
{
struct blk_integrity *bi;
struct bio_integrity_payload *bip = bio->bi_integrity;
unsigned int nr_sectors;
if (bio_integrity(bio) == 0)
return;
bi = bdev_get_integrity(bio->bi_bdev);
BUG_ON(bi == NULL);
BUG_ON(bip->bip_vcnt != 1);
nr_sectors = bio_integrity_hw_sectors(bi, sectors);
bp->bio1.bi_integrity = &bp->bip1;
bp->bio2.bi_integrity = &bp->bip2;
bp->iv1 = bip->bip_vec[0];
bp->iv2 = bip->bip_vec[0];
bp->bip1.bip_vec = &bp->iv1;
bp->bip2.bip_vec = &bp->iv2;
bp->iv1.bv_len = sectors * bi->tuple_size;
bp->iv2.bv_offset += sectors * bi->tuple_size;
bp->iv2.bv_len -= sectors * bi->tuple_size;
bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
}
EXPORT_SYMBOL(bio_integrity_split);
/**
* bio_integrity_clone - Callback for cloning bios with integrity metadata
* @bio: New bio
* @bio_src: Original bio
* @bs: bio_set to allocate bip from
*
* Description: Called to allocate a bip when cloning a bio
*/
int bio_integrity_clone(struct bio *bio, struct bio *bio_src, struct bio_set *bs)
{
struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
struct bio_integrity_payload *bip;
BUG_ON(bip_src == NULL);
bip = bio_integrity_alloc_bioset(bio, GFP_NOIO, bip_src->bip_vcnt, bs);
if (bip == NULL)
return -EIO;
memcpy(bip->bip_vec, bip_src->bip_vec,
bip_src->bip_vcnt * sizeof(struct bio_vec));
bip->bip_sector = bip_src->bip_sector;
bip->bip_vcnt = bip_src->bip_vcnt;
bip->bip_idx = bip_src->bip_idx;
return 0;
}
EXPORT_SYMBOL(bio_integrity_clone);
int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
bs->bio_integrity_pool = mempool_create_slab_pool(pool_size,
bio_integrity_slab);
if (!bs->bio_integrity_pool)
return -1;
return 0;
}
EXPORT_SYMBOL(bioset_integrity_create);
void bioset_integrity_free(struct bio_set *bs)
{
if (bs->bio_integrity_pool)
mempool_destroy(bs->bio_integrity_pool);
}
EXPORT_SYMBOL(bioset_integrity_free);
void __init bio_integrity_init_slab(void)
{
bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
SLAB_HWCACHE_ALIGN|SLAB_PANIC);
}
EXPORT_SYMBOL(bio_integrity_init_slab);
static int __init integrity_init(void)
{
kintegrityd_wq = create_workqueue("kintegrityd");
if (!kintegrityd_wq)
panic("Failed to create kintegrityd\n");
return 0;
}
subsys_initcall(integrity_init);

32
fs/bio.c
View file

@ -50,6 +50,11 @@ static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
*/
struct bio_set *fs_bio_set;
unsigned int bvec_nr_vecs(unsigned short idx)
{
return bvec_slabs[idx].nr_vecs;
}
struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs)
{
struct bio_vec *bvl;
@ -91,6 +96,9 @@ void bio_free(struct bio *bio, struct bio_set *bio_set)
mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]);
}
if (bio_integrity(bio))
bio_integrity_free(bio, bio_set);
mempool_free(bio, bio_set->bio_pool);
}
@ -249,9 +257,19 @@ struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
{
struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
if (b) {
b->bi_destructor = bio_fs_destructor;
__bio_clone(b, bio);
if (!b)
return NULL;
b->bi_destructor = bio_fs_destructor;
__bio_clone(b, bio);
if (bio_integrity(bio)) {
int ret;
ret = bio_integrity_clone(b, bio, fs_bio_set);
if (ret < 0)
return NULL;
}
return b;
@ -1223,6 +1241,9 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
bp->bio1.bi_private = bi;
bp->bio2.bi_private = pool;
if (bio_integrity(bi))
bio_integrity_split(bi, bp, first_sectors);
return bp;
}
@ -1264,6 +1285,7 @@ void bioset_free(struct bio_set *bs)
if (bs->bio_pool)
mempool_destroy(bs->bio_pool);
bioset_integrity_free(bs);
biovec_free_pools(bs);
kfree(bs);
@ -1280,6 +1302,9 @@ struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size)
if (!bs->bio_pool)
goto bad;
if (bioset_integrity_create(bs, bio_pool_size))
goto bad;
if (!biovec_create_pools(bs, bvec_pool_size))
return bs;
@ -1306,6 +1331,7 @@ static int __init init_bio(void)
{
bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
bio_integrity_init_slab();
biovec_init_slabs();
fs_bio_set = bioset_create(BIO_POOL_SIZE, 2);

94
include/linux/bio.h
View file

@ -64,6 +64,7 @@ struct bio_vec {
struct bio_set;
struct bio;
struct bio_integrity_payload;
typedef void (bio_end_io_t) (struct bio *, int);
typedef void (bio_destructor_t) (struct bio *);
@ -112,6 +113,9 @@ struct bio {
atomic_t bi_cnt; /* pin count */
void *bi_private;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
struct bio_integrity_payload *bi_integrity; /* data integrity */
#endif
bio_destructor_t *bi_destructor; /* destructor */
};
@ -271,6 +275,29 @@ static inline void *bio_data(struct bio *bio)
*/
#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
#if defined(CONFIG_BLK_DEV_INTEGRITY)
/*
* bio integrity payload
*/
struct bio_integrity_payload {
struct bio *bip_bio; /* parent bio */
struct bio_vec *bip_vec; /* integrity data vector */
sector_t bip_sector; /* virtual start sector */
void *bip_buf; /* generated integrity data */
bio_end_io_t *bip_end_io; /* saved I/O completion fn */
int bip_error; /* saved I/O error */
unsigned int bip_size;
unsigned short bip_pool; /* pool the ivec came from */
unsigned short bip_vcnt; /* # of integrity bio_vecs */
unsigned short bip_idx; /* current bip_vec index */
struct work_struct bip_work; /* I/O completion */
};
#endif /* CONFIG_BLK_DEV_INTEGRITY */
/*
* A bio_pair is used when we need to split a bio.
@ -283,10 +310,14 @@ static inline void *bio_data(struct bio *bio)
* in bio2.bi_private
*/
struct bio_pair {
struct bio bio1, bio2;
struct bio_vec bv1, bv2;
atomic_t cnt;
int error;
struct bio bio1, bio2;
struct bio_vec bv1, bv2;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
struct bio_integrity_payload bip1, bip2;
struct bio_vec iv1, iv2;
#endif
atomic_t cnt;
int error;
};
extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool,
int first_sectors);
@ -334,6 +365,7 @@ extern struct bio *bio_copy_user_iov(struct request_queue *, struct sg_iovec *,
extern int bio_uncopy_user(struct bio *);
void zero_fill_bio(struct bio *bio);
extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
extern unsigned int bvec_nr_vecs(unsigned short idx);
/*
* bio_set is used to allow other portions of the IO system to
@ -346,6 +378,9 @@ extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set
struct bio_set {
mempool_t *bio_pool;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
mempool_t *bio_integrity_pool;
#endif
mempool_t *bvec_pools[BIOVEC_NR_POOLS];
};
@ -410,5 +445,56 @@ static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
#if defined(CONFIG_BLK_DEV_INTEGRITY)
#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
#define bip_vec(bip) bip_vec_idx(bip, 0)
#define __bip_for_each_vec(bvl, bip, i, start_idx) \
for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
i < (bip)->bip_vcnt; \
bvl++, i++)
#define bip_for_each_vec(bvl, bip, i) \
__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
#define bio_integrity(bio) ((bio)->bi_integrity ? 1 : 0)
extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
extern void bio_integrity_free(struct bio *, struct bio_set *);
extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
extern int bio_integrity_enabled(struct bio *bio);
extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
extern int bio_integrity_prep(struct bio *);
extern void bio_integrity_endio(struct bio *, int);
extern void bio_integrity_advance(struct bio *, unsigned int);
extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *);
extern int bioset_integrity_create(struct bio_set *, int);
extern void bioset_integrity_free(struct bio_set *);
extern void bio_integrity_init_slab(void);
#else /* CONFIG_BLK_DEV_INTEGRITY */
#define bio_integrity(a) (0)
#define bioset_integrity_create(a, b) (0)
#define bio_integrity_prep(a) (0)
#define bio_integrity_enabled(a) (0)
#define bio_integrity_clone(a, b, c) (0)
#define bioset_integrity_free(a) do { } while (0)
#define bio_integrity_free(a, b) do { } while (0)
#define bio_integrity_endio(a, b) do { } while (0)
#define bio_integrity_advance(a, b) do { } while (0)
#define bio_integrity_trim(a, b, c) do { } while (0)
#define bio_integrity_split(a, b, c) do { } while (0)
#define bio_integrity_set_tag(a, b, c) do { } while (0)
#define bio_integrity_get_tag(a, b, c) do { } while (0)
#define bio_integrity_init_slab(a) do { } while (0)
#endif /* CONFIG_BLK_DEV_INTEGRITY */
#endif /* CONFIG_BLOCK */
#endif /* __LINUX_BIO_H */

105
include/linux/blkdev.h
View file

@ -112,6 +112,7 @@ enum rq_flag_bits {
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_RW_META, /* metadata io request */
__REQ_COPY_USER, /* contains copies of user pages */
__REQ_INTEGRITY, /* integrity metadata has been remapped */
__REQ_NR_BITS, /* stops here */
};
@ -134,6 +135,7 @@ enum rq_flag_bits {
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_RW_META (1 << __REQ_RW_META)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
#define BLK_MAX_CDB 16
@ -865,6 +867,109 @@ void kblockd_flush_work(struct work_struct *work);
MODULE_ALIAS("block-major-" __stringify(major) "-*")
#if defined(CONFIG_BLK_DEV_INTEGRITY)
#define INTEGRITY_FLAG_READ 1 /* verify data integrity on read */
#define INTEGRITY_FLAG_WRITE 2 /* generate data integrity on write */
struct blk_integrity_exchg {
void *prot_buf;
void *data_buf;
sector_t sector;
unsigned int data_size;
unsigned short sector_size;
const char *disk_name;
};
typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
struct blk_integrity {
integrity_gen_fn *generate_fn;
integrity_vrfy_fn *verify_fn;
integrity_set_tag_fn *set_tag_fn;
integrity_get_tag_fn *get_tag_fn;
unsigned short flags;
unsigned short tuple_size;
unsigned short sector_size;
unsigned short tag_size;
const char *name;
struct kobject kobj;
};
extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
extern void blk_integrity_unregister(struct gendisk *);
extern int blk_integrity_compare(struct block_device *, struct block_device *);
extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
extern int blk_rq_count_integrity_sg(struct request *);
static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
{
if (bi)
return bi->tuple_size;
return 0;
}
static inline struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
{
return bdev->bd_disk->integrity;
}
static inline unsigned int bdev_get_tag_size(struct block_device *bdev)
{
struct blk_integrity *bi = bdev_get_integrity(bdev);
if (bi)
return bi->tag_size;
return 0;
}
static inline int bdev_integrity_enabled(struct block_device *bdev, int rw)
{
struct blk_integrity *bi = bdev_get_integrity(bdev);
if (bi == NULL)
return 0;
if (rw == READ && bi->verify_fn != NULL &&
test_bit(INTEGRITY_FLAG_READ, &bi->flags))
return 1;
if (rw == WRITE && bi->generate_fn != NULL &&
test_bit(INTEGRITY_FLAG_WRITE, &bi->flags))
return 1;
return 0;
}
static inline int blk_integrity_rq(struct request *rq)
{
BUG_ON(rq->bio == NULL);
return bio_integrity(rq->bio);
}
#else /* CONFIG_BLK_DEV_INTEGRITY */
#define blk_integrity_rq(rq) (0)
#define blk_rq_count_integrity_sg(a) (0)
#define blk_rq_map_integrity_sg(a, b) (0)
#define bdev_get_integrity(a) (0)
#define bdev_get_tag_size(a) (0)
#define blk_integrity_compare(a, b) (0)
#define blk_integrity_register(a, b) (0)
#define blk_integrity_unregister(a) do { } while (0);
#endif /* CONFIG_BLK_DEV_INTEGRITY */
#else /* CONFIG_BLOCK */
/*
* stubs for when the block layer is configured out

3
include/linux/genhd.h
View file

@ -141,6 +141,9 @@ struct gendisk {
struct disk_stats dkstats;
#endif
struct work_struct async_notify;
#ifdef CONFIG_BLK_DEV_INTEGRITY
struct blk_integrity *integrity;
#endif
};
/*