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authorMartin K. Petersen <martin.petersen@oracle.com>2009-06-26 15:37:49 +0200
committerJens Axboe <jens.axboe@oracle.com>2009-07-01 10:56:25 +0200
commit7878cba9f0037f5599004b03a1260b32d9050360 (patch)
treebff5e1a47b6e64e45df0428925cc6db8542cad62 /fs/bio-integrity.c
parent6118b70b3a0b4c583439bb77600194c82f220ce3 (diff)
downloadlinux-7878cba9f0037f5599004b03a1260b32d9050360.tar.gz
block: Create bip slabs with embedded integrity vectors
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)>
Diffstat (limited to 'fs/bio-integrity.c')
-rw-r--r--fs/bio-integrity.c170
1 files changed, 125 insertions, 45 deletions
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index 31c46a241ba..49a34e7f730 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -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
@@ -25,63 +25,121 @@
#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 - Allocate integrity payload and attach it to bio
+ * 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(struct bio *bio,
- gfp_t gfp_mask,
- unsigned int nr_vecs)
+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;
- struct bio_vec *iv;
- unsigned long idx;
+ unsigned int idx = vecs_to_idx(nr_vecs);
BUG_ON(bio == NULL);
+ bip = 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;
- }
+ /* Lower order allocations come straight from slab */
+ if (!use_bip_pool(idx))
+ bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
- memset(bip, 0, sizeof(*bip));
+ /* Use mempool if lower order alloc failed or max vecs were requested */
+ if (bip == NULL) {
+ bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
- 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;
+ if (unlikely(bip == NULL)) {
+ printk(KERN_ERR "%s: could not alloc bip\n", __func__);
+ return NULL;
+ }
}
- bip->bip_pool = idx;
- bip->bip_vec = iv;
+ 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
+ * @gfp_mask: Memory allocation mask
+ * @nr_vecs: Number of integrity metadata scatter-gather elements
+ *
+ * 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(struct bio *bio,
+ gfp_t gfp_mask,
+ unsigned int nr_vecs)
+{
+ 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);
+
+ bs->bio_integrity_pool =
+ mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
+ if (!bs->bio_integrity_pool)
+ return -1;
+
+ return 0;
+}
+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");
- bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
- SLAB_HWCACHE_ALIGN|SLAB_PANIC);
+ for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
+ unsigned int size;
- 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");
+ size = sizeof(struct bio_integrity_payload)
+ + bip_slab[i].nr_vecs * sizeof(struct bio_vec);
- integrity_bio_set = bioset_create(BIO_POOL_SIZE, 0);
- if (!integrity_bio_set)
- panic("bio_integrity: can't allocate bio_set\n");
-
- return 0;
+ bip_slab[i].slab =
+ kmem_cache_create(bip_slab[i].name, size, 0,
+ SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+ }
}
-subsys_initcall(bio_integrity_init);