diff options
| -rw-r--r-- | block/Kconfig | 12 | ||||
| -rw-r--r-- | block/Makefile | 1 | ||||
| -rw-r--r-- | block/blk-core.c | 7 | ||||
| -rw-r--r-- | block/blk-integrity.c | 382 | ||||
| -rw-r--r-- | block/blk-merge.c | 3 | ||||
| -rw-r--r-- | block/blk.h | 8 | ||||
| -rw-r--r-- | block/elevator.c | 6 | ||||
| -rw-r--r-- | fs/Makefile | 1 | ||||
| -rw-r--r-- | fs/bio-integrity.c | 708 | ||||
| -rw-r--r-- | fs/bio.c | 32 | ||||
| -rw-r--r-- | include/linux/bio.h | 94 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 105 | ||||
| -rw-r--r-- | include/linux/genhd.h | 3 |
13 files changed, 1355 insertions, 7 deletions
diff --git a/block/Kconfig b/block/Kconfig index 3e97f2bc446..1ab7c15c8d7 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 5a43c7d7959..045f7b62e4b 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 1905aaba49f..e0fb0bcc0c1 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 00000000000..65f23ef38bb --- /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 651136aae76..5efc9e7a68b 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 59776ab4742..c79f30e1df5 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 902dd1344d5..1f5bfe69602 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 1e7a11bd4da..277b079dec9 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 00000000000..31b08878913 --- /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_integr |