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author | Martin K. Petersen <martin.petersen@oracle.com> | 2008-06-30 18:04:41 (GMT) |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2008-07-03 11:21:13 (GMT) |
commit | 7ba1ba12eeef0aa7113beb16410ef8b7c748e18b (patch) | |
tree | 4629aabe88bf095d58eabd2f451207695bb35b08 /include/linux/blkdev.h | |
parent | 51d654e1d885607a6edd02b337105fa5c28b6d33 (diff) | |
download | linux-fsl-qoriq-7ba1ba12eeef0aa7113beb16410ef8b7c748e18b.tar.xz |
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>
Diffstat (limited to 'include/linux/blkdev.h')
-rw-r--r-- | include/linux/blkdev.h | 105 |
1 files changed, 105 insertions, 0 deletions
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 @@ enum rq_flag_bits { __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 @@ enum rq_flag_bits { #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 @@ void kblockd_flush_work(struct work_struct *work); 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 |