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>
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
new file mode 100644
index 0000000..31b0887
--- /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);