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block: Create bip slabs with embedded integrity vectors

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This patch restores stacking ability to the block layer integrity
infrastructure by creating a set of dedicated bip slabs.  Each bip slab
has an embedded bio_vec array at the end.  This cuts down on memory
allocations and also simplifies the code compared to the original bvec
version.  Only the largest bip slab is backed by a mempool.  The pool is
contained in the bio_set so stacking drivers can ensure forward
progress.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.(none)>
This commit is contained in:
Martin K. Petersen
2009-06-26 15:37:49 +02:00
committed by Jens Axboe
parent 6118b70b3a
commit 7878cba9f0
5 changed files with 162 additions and 67 deletions
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190
fs/bio-integrity.c
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@ -1,7 +1,7 @@
/*
* bio-integrity.c - bio data integrity extensions
*
* Copyright (C) 2007, 2008 Oracle Corporation
* Copyright (C) 2007, 2008, 2009 Oracle Corporation
* Written by: Martin K. Petersen <martin.petersen@oracle.com>
*
* This program is free software; you can redistribute it and/or
@ -25,11 +25,94 @@
#include <linux/bio.h>
#include <linux/workqueue.h>
static struct kmem_cache *bio_integrity_slab __read_mostly;
static mempool_t *bio_integrity_pool;
static struct bio_set *integrity_bio_set;
struct integrity_slab {
struct kmem_cache *slab;
unsigned short nr_vecs;
char name[8];
};
#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
};
#undef IS
static struct workqueue_struct *kintegrityd_wq;
static inline unsigned int vecs_to_idx(unsigned int nr)
{
switch (nr) {
case 1:
return 0;
case 2 ... 4:
return 1;
case 5 ... 16:
return 2;
case 17 ... 64:
return 3;
case 65 ... 128:
return 4;
case 129 ... BIO_MAX_PAGES:
return 5;
default:
BUG();
}
}
static inline int use_bip_pool(unsigned int idx)
{
if (idx == BIOVEC_NR_POOLS)
return 1;
return 0;
}
/**
* bio_integrity_alloc_bioset - Allocate integrity payload and attach it to bio
* @bio: bio to attach integrity metadata to
* @gfp_mask: Memory allocation mask
* @nr_vecs: Number of integrity metadata scatter-gather elements
* @bs: bio_set to allocate from
*
* Description: This function prepares a bio for attaching integrity
* metadata. nr_vecs specifies the maximum number of pages containing
* integrity metadata that can be attached.
*/
struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *bio,
gfp_t gfp_mask,
unsigned int nr_vecs,
struct bio_set *bs)
{
struct bio_integrity_payload *bip;
unsigned int idx = vecs_to_idx(nr_vecs);
BUG_ON(bio == NULL);
bip = NULL;
/* Lower order allocations come straight from slab */
if (!use_bip_pool(idx))
bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
/* Use mempool if lower order alloc failed or max vecs were requested */
if (bip == NULL) {
bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
if (unlikely(bip == NULL)) {
printk(KERN_ERR "%s: could not alloc bip\n", __func__);
return NULL;
}
}
memset(bip, 0, sizeof(*bip));
bip->bip_slab = idx;
bip->bip_bio = bio;
bio->bi_integrity = bip;
return bip;
}
EXPORT_SYMBOL(bio_integrity_alloc_bioset);
/**
* bio_integrity_alloc - Allocate integrity payload and attach it to bio
* @bio: bio to attach integrity metadata to
@ -44,44 +127,19 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
gfp_t gfp_mask,
unsigned int nr_vecs)
{
struct bio_integrity_payload *bip;
struct bio_vec *iv;
unsigned long idx;
BUG_ON(bio == NULL);
bip = mempool_alloc(bio_integrity_pool, gfp_mask);
if (unlikely(bip == NULL)) {
printk(KERN_ERR "%s: could not alloc bip\n", __func__);
return NULL;
}
memset(bip, 0, sizeof(*bip));
iv = bvec_alloc_bs(gfp_mask, nr_vecs, &idx, integrity_bio_set);
if (unlikely(iv == NULL)) {
printk(KERN_ERR "%s: could not alloc bip_vec\n", __func__);
mempool_free(bip, bio_integrity_pool);
return NULL;
}
bip->bip_pool = idx;
bip->bip_vec = iv;
bip->bip_bio = bio;
bio->bi_integrity = bip;
return bip;
return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
}
EXPORT_SYMBOL(bio_integrity_alloc);
/**
* bio_integrity_free - Free bio integrity payload
* @bio: bio containing bip to be freed
* @bs: bio_set this bio was allocated from
*
* Description: Used to free the integrity portion of a bio. Usually
* called from bio_free().
*/
void bio_integrity_free(struct bio *bio)
void bio_integrity_free(struct bio *bio, struct bio_set *bs)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
@ -92,8 +150,10 @@ void bio_integrity_free(struct bio *bio)
&& bip->bip_buf != NULL)
kfree(bip->bip_buf);
bvec_free_bs(integrity_bio_set, bip->bip_vec, bip->bip_pool);
mempool_free(bip, bio_integrity_pool);
if (use_bip_pool(bip->bip_slab))
mempool_free(bip, bs->bio_integrity_pool);
else
kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);
bio->bi_integrity = NULL;
}
@ -114,7 +174,7 @@ int bio_integrity_add_page(struct bio *bio, struct page *page,
struct bio_integrity_payload *bip = bio->bi_integrity;
struct bio_vec *iv;
if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_pool)) {
if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
printk(KERN_ERR "%s: bip_vec full\n", __func__);
return 0;
}
@ -647,8 +707,8 @@ void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
bp->iv1 = bip->bip_vec[0];
bp->iv2 = bip->bip_vec[0];
bp->bip1.bip_vec = &bp->iv1;
bp->bip2.bip_vec = &bp->iv2;
bp->bip1.bip_vec[0] = bp->iv1;
bp->bip2.bip_vec[0] = bp->iv2;
bp->iv1.bv_len = sectors * bi->tuple_size;
bp->iv2.bv_offset += sectors * bi->tuple_size;
@ -667,17 +727,19 @@ EXPORT_SYMBOL(bio_integrity_split);
* @bio: New bio
* @bio_src: Original bio
* @gfp_mask: Memory allocation mask
* @bs: bio_set to allocate bip from
*
* Description: Called to allocate a bip when cloning a bio
*/
int bio_integrity_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp_mask)
int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
gfp_t gfp_mask, struct bio_set *bs)
{
struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
struct bio_integrity_payload *bip;
BUG_ON(bip_src == NULL);
bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
if (bip == NULL)
return -EIO;
@ -693,25 +755,43 @@ int bio_integrity_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp_mask)
}
EXPORT_SYMBOL(bio_integrity_clone);
static int __init bio_integrity_init(void)
int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
kintegrityd_wq = create_workqueue("kintegrityd");
unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
if (!kintegrityd_wq)
panic("Failed to create kintegrityd\n");
bs->bio_integrity_pool =
mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
SLAB_HWCACHE_ALIGN|SLAB_PANIC);
bio_integrity_pool = mempool_create_slab_pool(BIO_POOL_SIZE,
bio_integrity_slab);
if (!bio_integrity_pool)
panic("bio_integrity: can't allocate bip pool\n");
integrity_bio_set = bioset_create(BIO_POOL_SIZE, 0);
if (!integrity_bio_set)
panic("bio_integrity: can't allocate bio_set\n");
if (!bs->bio_integrity_pool)
return -1;
return 0;
}
subsys_initcall(bio_integrity_init);
EXPORT_SYMBOL(bioset_integrity_create);
void bioset_integrity_free(struct bio_set *bs)
{
if (bs->bio_integrity_pool)
mempool_destroy(bs->bio_integrity_pool);
}
EXPORT_SYMBOL(bioset_integrity_free);
void __init bio_integrity_init(void)
{
unsigned int i;
kintegrityd_wq = create_workqueue("kintegrityd");
if (!kintegrityd_wq)
panic("Failed to create kintegrityd\n");
for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
unsigned int size;
size = sizeof(struct bio_integrity_payload)
+ bip_slab[i].nr_vecs * sizeof(struct bio_vec);
bip_slab[i].slab =
kmem_cache_create(bip_slab[i].name, size, 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
}
}