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/include/linux/bio.h b/include/linux/bio.h
index 49dfb3c..6bfc3e8 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -64,6 +64,7 @@
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 @@
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 @@
*/
#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 @@
* 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 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 @@
struct bio_set {
mempool_t *bio_pool;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+ mempool_t *bio_integrity_pool;
+#endif
mempool_t *bvec_pools[BIOVEC_NR_POOLS];
};
@@ -410,5 +445,56 @@
__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
+#define bip_vec(bip) bip_vec_idx(bip, 0)
+
+#define __bip_for_each_vec(bvl, bip, i, start_idx) \
+ for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
+ i < (bip)->bip_vcnt; \
+ bvl++, i++)
+
+#define bip_for_each_vec(bvl, bip, i) \
+ __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
+
+#define bio_integrity(bio) ((bio)->bi_integrity ? 1 : 0)
+
+extern struct 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 6a3da67..4a9ed45 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -112,6 +112,7 @@
__REQ_ALLOCED, /* request came from our alloc pool */
__REQ_RW_META, /* metadata io request */
__REQ_COPY_USER, /* contains copies of user pages */
+ __REQ_INTEGRITY, /* integrity metadata has been remapped */
__REQ_NR_BITS, /* stops here */
};
@@ -134,6 +135,7 @@
#define REQ_ALLOCED (1 << __REQ_ALLOCED)
#define REQ_RW_META (1 << __REQ_RW_META)
#define REQ_COPY_USER (1 << __REQ_COPY_USER)
+#define REQ_INTEGRITY (1 << __REQ_INTEGRITY)
#define BLK_MAX_CDB 16
@@ -865,6 +867,109 @@
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 ae7aec3..524ec96 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -141,6 +141,9 @@
struct disk_stats dkstats;
#endif
struct work_struct async_notify;
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+ struct blk_integrity *integrity;
+#endif
};
/*