diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bio-integrity.c | 2 | ||||
| -rw-r--r-- | fs/bio.c | 191 |
2 files changed, 162 insertions, 31 deletions
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c index 19caf7c..77ebc3c 100644 --- a/fs/bio-integrity.c +++ b/fs/bio-integrity.c @@ -111,7 +111,7 @@ void bio_integrity_free(struct bio *bio, struct bio_set *bs) && bip->bip_buf != NULL) kfree(bip->bip_buf); - mempool_free(bip->bip_vec, bs->bvec_pools[bip->bip_pool]); + bvec_free_bs(bs, bip->bip_vec, bip->bip_pool); mempool_free(bip, bs->bio_integrity_pool); bio->bi_integrity = NULL; @@ -31,8 +31,6 @@ DEFINE_TRACE(block_split); -static struct kmem_cache *bio_slab __read_mostly; - static mempool_t *bio_split_pool __read_mostly; /* @@ -40,9 +38,8 @@ static mempool_t *bio_split_pool __read_mostly; * break badly! cannot be bigger than what you can fit into an * unsigned short */ - #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } -static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { +struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), }; #undef BV @@ -53,11 +50,119 @@ static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { */ struct bio_set *fs_bio_set; +/* + * Our slab pool management + */ +struct bio_slab { + struct kmem_cache *slab; + unsigned int slab_ref; + unsigned int slab_size; + char name[8]; +}; +static DEFINE_MUTEX(bio_slab_lock); +static struct bio_slab *bio_slabs; +static unsigned int bio_slab_nr, bio_slab_max; + +static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) +{ + unsigned int sz = sizeof(struct bio) + extra_size; + struct kmem_cache *slab = NULL; + struct bio_slab *bslab; + unsigned int i, entry = -1; + + mutex_lock(&bio_slab_lock); + + i = 0; + while (i < bio_slab_nr) { + struct bio_slab *bslab = &bio_slabs[i]; + + if (!bslab->slab && entry == -1) + entry = i; + else if (bslab->slab_size == sz) { + slab = bslab->slab; + bslab->slab_ref++; + break; + } + i++; + } + + if (slab) + goto out_unlock; + + if (bio_slab_nr == bio_slab_max && entry == -1) { + bio_slab_max <<= 1; + bio_slabs = krealloc(bio_slabs, + bio_slab_max * sizeof(struct bio_slab), + GFP_KERNEL); + if (!bio_slabs) + goto out_unlock; + } + if (entry == -1) + entry = bio_slab_nr++; + + bslab = &bio_slabs[entry]; + + snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); + slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL); + if (!slab) + goto out_unlock; + + printk("bio: create slab <%s> at %d\n", bslab->name, entry); + bslab->slab = slab; + bslab->slab_ref = 1; + bslab->slab_size = sz; +out_unlock: + mutex_unlock(&bio_slab_lock); + return slab; +} + +static void bio_put_slab(struct bio_set *bs) +{ + struct bio_slab *bslab = NULL; + unsigned int i; + + mutex_lock(&bio_slab_lock); + + for (i = 0; i < bio_slab_nr; i++) { + if (bs->bio_slab == bio_slabs[i].slab) { + bslab = &bio_slabs[i]; + break; + } + } + + if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) + goto out; + + WARN_ON(!bslab->slab_ref); + + if (--bslab->slab_ref) + goto out; + + kmem_cache_destroy(bslab->slab); + bslab->slab = NULL; + +out: + mutex_unlock(&bio_slab_lock); +} + unsigned int bvec_nr_vecs(unsigned short idx) { return bvec_slabs[idx].nr_vecs; } +void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx) +{ + BIO_BUG_ON(idx >= BIOVEC_NR_POOLS); + + if (idx == BIOVEC_MAX_IDX) + mempool_free(bv, bs->bvec_pool); + else { + struct biovec_slab *bvs = bvec_slabs + idx; + + kmem_cache_free(bvs->slab, bv); + } +} + struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) { @@ -134,24 +239,22 @@ fallback: void bio_free(struct bio *bio, struct bio_set *bs) { - if (bio->bi_io_vec) { - const int pool_idx = BIO_POOL_IDX(bio); + void *p; - BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS); - - if (pool_idx == BIOVEC_MAX_IDX) - mempool_free(bio->bi_io_vec, bs->bvec_pool); - else { - struct biovec_slab *bvs = bvec_slabs + pool_idx; - - kmem_cache_free(bvs->slab, bio->bi_io_vec); - } - } + if (bio->bi_io_vec) + bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); if (bio_integrity(bio)) bio_integrity_free(bio, bs); - mempool_free(bio, bs->bio_pool); + /* + * If we have front padding, adjust the bio pointer before freeing + */ + p = bio; + if (bs->front_pad) + p -= bs->front_pad; + + mempool_free(p, bs->bio_pool); } /* @@ -188,16 +291,20 @@ void bio_init(struct bio *bio) * for a &struct bio to become free. If a %NULL @bs is passed in, we will * fall back to just using @kmalloc to allocate the required memory. * - * allocate bio and iovecs from the memory pools specified by the - * bio_set structure, or @kmalloc if none given. + * Note that the caller must set ->bi_destructor on succesful return + * of a bio, to do the appropriate freeing of the bio once the reference + * count drops to zero. **/ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) { - struct bio *bio; + struct bio *bio = NULL; + + if (bs) { + void *p = mempool_alloc(bs->bio_pool, gfp_mask); - if (bs) - bio = mempool_alloc(bs->bio_pool, gfp_mask); - else + if (p) + bio = p + bs->front_pad; + } else bio = kmalloc(sizeof(*bio), gfp_mask); if (likely(bio)) { @@ -1398,11 +1505,25 @@ void bioset_free(struct bio_set *bs) bioset_integrity_free(bs); biovec_free_pools(bs); + bio_put_slab(bs); kfree(bs); } -struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size) +/** + * bioset_create - Create a bio_set + * @pool_size: Number of bio and bio_vecs to cache in the mempool + * @front_pad: Number of bytes to allocate in front of the returned bio + * + * Description: + * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller + * to ask for a number of bytes to be allocated in front of the bio. + * Front pad allocation is useful for embedding the bio inside + * another structure, to avoid allocating extra data to go with the bio. + * Note that the bio must be embedded at the END of that structure always, + * or things will break badly. + */ +struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) { struct bio_set *bs; @@ -1410,16 +1531,22 @@ struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size) if (!bs) return NULL; - bs->bio_slab = bio_slab; + bs->front_pad = front_pad; - bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bs->bio_slab); + bs->bio_slab = bio_find_or_create_slab(front_pad); + if (!bs->bio_slab) { + kfree(bs); + return NULL; + } + + bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); if (!bs->bio_pool) goto bad; - if (bioset_integrity_create(bs, bio_pool_size)) + if (bioset_integrity_create(bs, pool_size)) goto bad; - if (!biovec_create_pools(bs, bvec_pool_size)) + if (!biovec_create_pools(bs, pool_size)) return bs; bad: @@ -1443,12 +1570,16 @@ static void __init biovec_init_slabs(void) static int __init init_bio(void) { - bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC); + bio_slab_max = 2; + bio_slab_nr = 0; + bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); + if (!bio_slabs) + panic("bio: can't allocate bios\n"); bio_integrity_init_slab(); biovec_init_slabs(); - fs_bio_set = bioset_create(BIO_POOL_SIZE, 2); + fs_bio_set = bioset_create(BIO_POOL_SIZE, 0); if (!fs_bio_set) panic("bio: can't allocate bios\n"); |
