block: Block layer data integrity support

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>

13 files changed, 1355 insertions, 7 deletions

diff --git a/block/Kconfig b/block/Kconfig
index 3e97f2bc446f..1ab7c15c8d7a 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -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
diff --git a/block/Makefile b/block/Makefile
index 5a43c7d79594..045f7b62e4bb 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -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
diff --git a/block/blk-core.c b/block/blk-core.c
index 1905aaba49fb..e0fb0bcc0c17 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -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);
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
new file mode 100644
index 000000000000..65f23ef38bbe
--- /dev/null
+++ b/block/blk-integrity.c
@@ -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);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 651136aae76e..5efc9e7a68b7 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -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
diff --git a/block/blk.h b/block/blk.h
index 59776ab4742a..c79f30e1df52 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -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
diff --git a/block/elevator.c b/block/elevator.c
index 902dd1344d56..1f5bfe696026 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -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;
 
diff --git a/fs/Makefile b/fs/Makefile
index 1e7a11bd4da1..277b079dec9e 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -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
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
new file mode 100644
index 000000000000..31b08878913d
--- /dev/null
+++ b/fs/bio-integrity.c
@@ -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);
diff --git a/fs/bio.c b/fs/bio.c
index 7a6598abc967..7761c84c7032 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -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);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 49dfb3cb7460..6bfc3e8d9d89 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -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 */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6a3da6717135..4a9ed45270ff 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -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
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index ae7aec3cabee..524ec96f5a23 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -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
 };
 
 /*