From 7ba1ba12eeef0aa7113beb16410ef8b7c748e18b Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Mon, 30 Jun 2008 20:04:41 +0200 Subject: 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 Signed-off-by: Jens Axboe --- include/linux/bio.h | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 90 insertions(+), 4 deletions(-) (limited to 'include/linux/bio.h') diff --git a/include/linux/bio.h b/include/linux/bio.h index 49dfb3cb746..6bfc3e8d9d8 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 */ -- cgit v1.2.3