From 51d654e1d885607a6edd02b337105fa5c28b6d33 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 17 Jun 2008 18:59:56 +0200 Subject: block: Globalize bio_set and bio_vec_slab Move struct bio_set and biovec_slab definitions to bio.h so they can be used outside of bio.c. Signed-off-by: Martin K. Petersen Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe --- fs/bio.c | 30 ++---------------------------- 1 file changed, 2 insertions(+), 28 deletions(-) (limited to 'fs/bio.c') diff --git a/fs/bio.c b/fs/bio.c index 78562574cb52..7a6598abc967 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -28,25 +28,10 @@ #include #include /* for struct sg_iovec */ -#define BIO_POOL_SIZE 2 - static struct kmem_cache *bio_slab __read_mostly; -#define BIOVEC_NR_POOLS 6 - -/* - * a small number of entries is fine, not going to be performance critical. - * basically we just need to survive - */ -#define BIO_SPLIT_ENTRIES 2 mempool_t *bio_split_pool __read_mostly; -struct biovec_slab { - int nr_vecs; - char *name; - struct kmem_cache *slab; -}; - /* * if you change this list, also change bvec_alloc or things will * break badly! cannot be bigger than what you can fit into an @@ -59,24 +44,13 @@ static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { }; #undef BV -/* - * bio_set is used to allow other portions of the IO system to - * allocate their own private memory pools for bio and iovec structures. - * These memory pools in turn all allocate from the bio_slab - * and the bvec_slabs[]. - */ -struct bio_set { - mempool_t *bio_pool; - mempool_t *bvec_pools[BIOVEC_NR_POOLS]; -}; - /* * fs_bio_set is the bio_set containing bio and iovec memory pools used by * IO code that does not need private memory pools. */ -static struct bio_set *fs_bio_set; +struct bio_set *fs_bio_set; -static inline struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) +struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) { struct bio_vec *bvl; -- cgit v1.2.3 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 --- fs/bio.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) (limited to 'fs/bio.c') diff --git a/fs/bio.c b/fs/bio.c index 7a6598abc967..7761c84c7032 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -50,6 +50,11 @@ static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { */ struct bio_set *fs_bio_set; +unsigned int bvec_nr_vecs(unsigned short idx) +{ + return bvec_slabs[idx].nr_vecs; +} + struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) { struct bio_vec *bvl; @@ -91,6 +96,9 @@ void bio_free(struct bio *bio, struct bio_set *bio_set) mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]); } + if (bio_integrity(bio)) + bio_integrity_free(bio, bio_set); + mempool_free(bio, bio_set->bio_pool); } @@ -249,9 +257,19 @@ struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) { struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); - if (b) { - b->bi_destructor = bio_fs_destructor; - __bio_clone(b, bio); + if (!b) + return NULL; + + b->bi_destructor = bio_fs_destructor; + __bio_clone(b, bio); + + if (bio_integrity(bio)) { + int ret; + + ret = bio_integrity_clone(b, bio, fs_bio_set); + + if (ret < 0) + return NULL; } return b; @@ -1223,6 +1241,9 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) bp->bio1.bi_private = bi; bp->bio2.bi_private = pool; + if (bio_integrity(bi)) + bio_integrity_split(bi, bp, first_sectors); + return bp; } @@ -1264,6 +1285,7 @@ void bioset_free(struct bio_set *bs) if (bs->bio_pool) mempool_destroy(bs->bio_pool); + bioset_integrity_free(bs); biovec_free_pools(bs); kfree(bs); @@ -1280,6 +1302,9 @@ struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size) if (!bs->bio_pool) goto bad; + if (bioset_integrity_create(bs, bio_pool_size)) + goto bad; + if (!biovec_create_pools(bs, bvec_pool_size)) return bs; @@ -1306,6 +1331,7 @@ static int __init init_bio(void) { bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC); + bio_integrity_init_slab(); biovec_init_slabs(); fs_bio_set = bioset_create(BIO_POOL_SIZE, 2); -- cgit v1.2.3 From cc371e66e340f35eed8dc4651c7c18e754c7fb26 Mon Sep 17 00:00:00 2001 From: Alasdair G Kergon Date: Thu, 3 Jul 2008 09:53:43 +0200 Subject: Add bvec_merge_data to handle stacked devices and ->merge_bvec() When devices are stacked, one device's merge_bvec_fn may need to perform the mapping and then call one or more functions for its underlying devices. The following bio fields are used: bio->bi_sector bio->bi_bdev bio->bi_size bio->bi_rw using bio_data_dir() This patch creates a new struct bvec_merge_data holding a copy of those fields to avoid having to change them directly in the struct bio when going down the stack only to have to change them back again on the way back up. (And then when the bio gets mapped for real, the whole exercise gets repeated, but that's a problem for another day...) Signed-off-by: Alasdair G Kergon Cc: Neil Brown Cc: Milan Broz Signed-off-by: Jens Axboe --- fs/bio.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) (limited to 'fs/bio.c') diff --git a/fs/bio.c b/fs/bio.c index 7761c84c7032..88322b066acb 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -325,10 +325,19 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page if (page == prev->bv_page && offset == prev->bv_offset + prev->bv_len) { prev->bv_len += len; - if (q->merge_bvec_fn && - q->merge_bvec_fn(q, bio, prev) < len) { - prev->bv_len -= len; - return 0; + + if (q->merge_bvec_fn) { + struct bvec_merge_data bvm = { + .bi_bdev = bio->bi_bdev, + .bi_sector = bio->bi_sector, + .bi_size = bio->bi_size, + .bi_rw = bio->bi_rw, + }; + + if (q->merge_bvec_fn(q, &bvm, prev) < len) { + prev->bv_len -= len; + return 0; + } } goto done; @@ -369,11 +378,18 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page * queue to get further control */ if (q->merge_bvec_fn) { + struct bvec_merge_data bvm = { + .bi_bdev = bio->bi_bdev, + .bi_sector = bio->bi_sector, + .bi_size = bio->bi_size, + .bi_rw = bio->bi_rw, + }; + /* * merge_bvec_fn() returns number of bytes it can accept * at this offset */ - if (q->merge_bvec_fn(q, bio, bvec) < len) { + if (q->merge_bvec_fn(q, &bvm, bvec) < len) { bvec->bv_page = NULL; bvec->bv_len = 0; bvec->bv_offset = 0; -- cgit v1.2.3