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 */