[PATCH 2 of 3] block: Block layer data integrity support

Martin K. Petersen
2008-06-16T04:13:31Z

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>

---
13 files changed, 1340 insertions(+), 3 deletions(-)
block/Kconfig | 12
block/Makefile | 1
block/blk-core.c | 7
block/blk-integrity.c | 385 ++++++++++++++++++++++++++
block/blk-merge.c | 3
block/blk.h | 8
block/elevator.c | 6
fs/Makefile | 1
fs/bio-integrity.c | 700 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/bio.c | 32 +-
include/linux/bio.h | 86 +++++
include/linux/blkdev.h | 99 ++++++
include/linux/genhd.h | 3

diff -r 24902abbf2b6 -r 91ceabd365c3 block/Kconfig
--- a/block/Kconfig Fri Jun 13 19:24:49 2008 -0400
+++ b/block/Kconfig Fri Jun 13 19:24:49 2008 -0400
@@ -81,6 +81,18 @@

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.
+
endif # BLOCK

config BLOCK_COMPAT
diff -r 24902abbf2b6 -r 91ceabd365c3 block/Makefile
--- a/block/Makefile Fri Jun 13 19:24:49 2008 -0400
+++ b/block/Makefile Fri Jun 13 19:24:49 2008 -0400
@@ -14,3 +14,4 @@

obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
+obj-$(CONFIG_BLK_DEV_INTEGRITY) += blk-integrity.o
diff -r 24902abbf2b6 -r 91ceabd365c3 block/blk-core.c
--- a/block/blk-core.c Fri Jun 13 19:24:49 2008 -0400
+++ b/block/blk-core.c Fri Jun 13 19:24:49 2008 -0400
@@ -143,6 +143,10 @@

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 @@
*/
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);
diff -r 24902abbf2b6 -r 91ceabd365c3 block/blk-integrity.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/block/blk-integrity.c Fri Jun 13 19:24:49 2008 -0400
@@ -0,0 +1,385 @@
+/*
+ * 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))
+ ;
+ else
+ 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);
+ ssize_t ret = -EIO;
+
+ if (entry->show)
+ ret = entry->show(bi, page);
+
+ return ret;
+}
+
+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 == 1)
+ 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 == 1)
+ 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"))
+ 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);
+}
+EXPORT_SYMBOL(blk_integrity_unregister);
diff -r 24902abbf2b6 -r 91ceabd365c3 block/blk-merge.c
--- a/block/blk-merge.c Fri Jun 13 19:24:49 2008 -0400
+++ b/block/blk-merge.c Fri Jun 13 19:24:49 2008 -0400
@@ -441,6 +441,9 @@
|| 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
diff -r 24902abbf2b6 -r 91ceabd365c3 block/blk.h
--- a/block/blk.h Fri Jun 13 19:24:49 2008 -0400
+++ b/block/blk.h Fri Jun 13 19:24:49 2008 -0400
@@ -51,4 +51,12 @@
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
diff -r 24902abbf2b6 -r 91ceabd365c3 block/elevator.c
--- a/block/elevator.c Fri Jun 13 19:24:49 2008 -0400
+++ b/block/elevator.c Fri Jun 13 19:24:49 2008 -0400
@@ -84,6 +84,12 @@
* must be same device and not a special request
*/
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))
diff -r 24902abbf2b6 -r 91ceabd365c3 fs/Makefile
--- a/fs/Makefile Fri Jun 13 19:24:49 2008 -0400
+++ b/fs/Makefile Fri Jun 13 19:24:49 2008 -0400
@@ -19,6 +19,7 @@
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
diff -r 24902abbf2b6 -r 91ceabd365c3 fs/bio-integrity.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/fs/bio-integrity.c Fri Jun 13 19:24:49 2008 -0400
@@ -0,0 +1,700 @@
+/*
+ * 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 bip *bio_integrity_alloc_bioset(struct bio *bio, gfp_t gfp_mask, unsigned int nr_vecs, struct bio_set *bs)
+{
+ struct bip *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 bip *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 bip *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 bip *bip;
+ struct bio_vec *iv;
+
+ bip = bio->bi_integrity;
+
+ 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_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 bip *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 = DIV_ROUND_UP(len, bi->tag_size);
+
+ if (bi->sector_size == 4096)
+ nr_sectors >>= 3;
+
+ 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) {
+ bix.data_buf = kmap_atomic(bv->bv_page, KM_USER0)
+ + 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(bv->bv_page, 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 bip *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 = bio_sectors(bio);
+
+ bi = bdev_get_integrity(bio->bi_bdev);
+ q = bdev_get_queue(bio->bi_bdev);
+ BUG_ON(bi == NULL);
+ BUG_ON(bio_integrity(bio));
+
+ if (bi->sector_size == 4096)
+ sectors >>= 3;
+
+ /* Allocate kernel buffer for protection data */
+ len = sectors * blk_integrity_tuple_size(bi);
+ buf = kmalloc(len, GFP_NOIO | 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;
+
+ 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) {
+ bix.data_buf = kmap_atomic(bv->bv_page, KM_USER0)
+ + 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(bv->bv_page, KM_USER0);
+ return ret;
+ }
+
+ 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(bv->bv_page, KM_USER0);
+ }
+
+ return 0;
+}
+
+/**
+ * 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 bip *bip = container_of(work, struct bip, 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 bip *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 bip *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 bip *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 bip *bip = bio->bi_integrity;
+ struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
+ unsigned int sectors;
+
+ BUG_ON(bip == NULL);
+ BUG_ON(bi == NULL);
+
+ sectors = bytes_done >> 9;
+
+ if (bi->sector_size == 4096)
+ sectors >>= 3;
+
+ bio_integrity_mark_head(bip, 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 bip *bip = bio->bi_integrity;
+ struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
+
+ BUG_ON(bip == NULL);
+ BUG_ON(bi == NULL);
+ BUG_ON(!bio_flagged(bio, BIO_CLONED));
+
+ if (bi->sector_size == 4096)
+ sectors >>= 3;
+
+ 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 bip *bip = bio->bi_integrity;
+
+ if (bio_integrity(bio) == 0)
+ return;
+
+ bi = bdev_get_integrity(bio->bi_bdev);
+ BUG_ON(bi == NULL);
+ BUG_ON(bip->bip_vcnt != 1);
+
+ if (bi->sector_size == 4096)
+ sectors >>= 3;
+
+ 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 + 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 bip *bip_src = bio_src->bi_integrity;
+ struct bip *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(bip, 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);
diff -r 24902abbf2b6 -r 91ceabd365c3 fs/bio.c
--- a/fs/bio.c Fri Jun 13 19:24:49 2008 -0400
+++ b/fs/bio.c Fri Jun 13 19:24:49 2008 -0400
@@ -50,6 +50,11 @@
*/
struct bio_set *fs_bio_set;

+inline 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;
@@ -90,6 +95,9 @@

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 *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 @@
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 @@
if (bs->bio_pool)
mempool_destroy(bs->bio_pool);

+ bioset_integrity_free(bs);
biovec_free_pools(bs);

kfree(bs);
@@ -1278,6 +1300,9 @@

bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bio_slab);
if (!bs->bio_pool)
+ goto bad;
+
+ if (bioset_integrity_create(bs, bio_pool_size))
goto bad;

if (!biovec_create_pools(bs, bvec_pool_size))
@@ -1306,6 +1331,7 @@
{
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);
diff -r 24902abbf2b6 -r 91ceabd365c3 include/linux/bio.h
--- a/include/linux/bio.h Fri Jun 13 19:24:49 2008 -0400
+++ b/include/linux/bio.h Fri Jun 13 19:24:49 2008 -0400
@@ -64,6 +64,7 @@

struct bio_set;
struct bio;
+struct bip;
typedef void (bio_end_io_t) (struct bio *, int);
typedef void (bio_destructor_t) (struct bio *);

@@ -112,6 +113,9 @@
atomic_t bi_cnt; /* pin count */

void *bi_private;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ struct bip *bi_integrity; /* data integrity */
+#endif

bio_destructor_t *bi_destructor; /* destructor */
};
@@ -271,6 +275,29 @@
*/
#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)

+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+/*
+ * bio integrity payload
+ */
+struct bip {
+ 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.
@@ -285,6 +312,10 @@
struct bio_pair {
struct bio bio1, bio2;
struct bio_vec bv1, bv2;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ struct bip bip1, bip2;
+ struct bio_vec iv1, iv2;
+#endif
atomic_t cnt;
int error;
};
@@ -334,6 +365,7 @@
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 inline 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 @@

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 @@
__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 bip *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
+extern struct bip *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 */
diff -r 24902abbf2b6 -r 91ceabd365c3 include/linux/blkdev.h
--- a/include/linux/blkdev.h Fri Jun 13 19:24:49 2008 -0400
+++ b/include/linux/blkdev.h Fri Jun 13 19:24:49 2008 -0400
@@ -113,6 +113,7 @@
__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 */
};

@@ -135,6 +136,7 @@
#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

@@ -866,6 +868,103 @@
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)
+{
+ return (bi == NULL) ? 0 : bi->tuple_size;
+}
+
+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);
+
+ return (bi == NULL) ? 0 : bi->tag_size;
+}
+
+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
diff -r 24902abbf2b6 -r 91ceabd365c3 include/linux/genhd.h
--- a/include/linux/genhd.h Fri Jun 13 19:24:49 2008 -0400
+++ b/include/linux/genhd.h Fri Jun 13 19:24:49 2008 -0400
@@ -141,6 +141,9 @@
struct disk_stats dkstats;
#endif
struct work_struct async_notify;
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+ struct blk_integrity *integrity;
+#endif
};

/*