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block: simplify and cleanup bvec pool handling

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Instead of a flag and an index just make sure an index of 0 means
no need to free the bvec array.  Also move the constants related
to the bvec pools together and use a consistent naming scheme for
them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2016-07-19 11:28:42 +02:00 committed by Jens Axboe
parent 70246286e9
commit ed996a52c8
5 changed files with 36 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
block/bio-integrity.c
View File

@ -53,7 +53,6 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
{
struct bio_integrity_payload *bip;
struct bio_set *bs = bio->bi_pool;
unsigned long idx = BIO_POOL_NONE;
unsigned inline_vecs;
if (!bs || !bs->bio_integrity_pool) {
@ -71,17 +70,19 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
memset(bip, 0, sizeof(*bip));
if (nr_vecs > inline_vecs) {
unsigned long idx = 0;
bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
bs->bvec_integrity_pool);
if (!bip->bip_vec)
goto err;
bip->bip_max_vcnt = bvec_nr_vecs(idx);
bip->bip_slab = idx;
} else {
bip->bip_vec = bip->bip_inline_vecs;
bip->bip_max_vcnt = inline_vecs;
}
bip->bip_slab = idx;
bip->bip_bio = bio;
bio->bi_integrity = bip;
bio->bi_rw |= REQ_INTEGRITY;
@ -110,9 +111,7 @@ void bio_integrity_free(struct bio *bio)
bip->bip_vec->bv_offset);
if (bs && bs->bio_integrity_pool) {
if (bip->bip_slab != BIO_POOL_NONE)
bvec_free(bs->bvec_integrity_pool, bip->bip_vec,
bip->bip_slab);
bvec_free(bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);
mempool_free(bip, bs->bio_integrity_pool);
} else {

32
block/bio.c
View File

@ -43,7 +43,7 @@
* unsigned short
*/
#define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = {
BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
};
#undef BV
@ -160,11 +160,15 @@ unsigned int bvec_nr_vecs(unsigned short idx)
void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
{
BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
if (!idx)
return;
idx--;
if (idx == BIOVEC_MAX_IDX)
BIO_BUG_ON(idx >= BVEC_POOL_NR);
if (idx == BVEC_POOL_MAX) {
mempool_free(bv, pool);
else {
} else {
struct biovec_slab *bvs = bvec_slabs + idx;
kmem_cache_free(bvs->slab, bv);
@ -206,7 +210,7 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
* idx now points to the pool we want to allocate from. only the
* 1-vec entry pool is mempool backed.
*/
if (*idx == BIOVEC_MAX_IDX) {
if (*idx == BVEC_POOL_MAX) {
fallback:
bvl = mempool_alloc(pool, gfp_mask);
} else {
@ -226,11 +230,12 @@ fallback:
*/
bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) {
*idx = BIOVEC_MAX_IDX;
*idx = BVEC_POOL_MAX;
goto fallback;
}
}
(*idx)++;
return bvl;
}
@ -250,8 +255,7 @@ static void bio_free(struct bio *bio)
__bio_free(bio);
if (bs) {
if (bio_flagged(bio, BIO_OWNS_VEC))
bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio));
bvec_free(bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio));
/*
* If we have front padding, adjust the bio pointer before freeing
@ -420,7 +424,6 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
gfp_t saved_gfp = gfp_mask;
unsigned front_pad;
unsigned inline_vecs;
unsigned long idx = BIO_POOL_NONE;
struct bio_vec *bvl = NULL;
struct bio *bio;
void *p;
@ -480,6 +483,8 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
bio_init(bio);
if (nr_iovecs > inline_vecs) {
unsigned long idx = 0;
bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
if (!bvl && gfp_mask != saved_gfp) {
punt_bios_to_rescuer(bs);
@ -490,13 +495,12 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
if (unlikely(!bvl))
goto err_free;
bio_set_flag(bio, BIO_OWNS_VEC);
bio->bi_flags |= idx << BVEC_POOL_OFFSET;
} else if (nr_iovecs) {
bvl = bio->bi_inline_vecs;
}
bio->bi_pool = bs;
bio->bi_flags |= idx << BIO_POOL_OFFSET;
bio->bi_max_vecs = nr_iovecs;
bio->bi_io_vec = bvl;
return bio;
@ -568,7 +572,7 @@ EXPORT_SYMBOL(bio_phys_segments);
*/
void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
{
BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE);
BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
/*
* most users will be overriding ->bi_bdev with a new target,
@ -1832,7 +1836,7 @@ EXPORT_SYMBOL_GPL(bio_trim);
*/
mempool_t *biovec_create_pool(int pool_entries)
{
struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX;
return mempool_create_slab_pool(pool_entries, bp->slab);
}
@ -2009,7 +2013,7 @@ static void __init biovec_init_slabs(void)
{
int i;
for (i = 0; i < BIOVEC_NR_POOLS; i++) {
for (i = 0; i < BVEC_POOL_NR; i++) {
int size;
struct biovec_slab *bvs = bvec_slabs + i;

1
drivers/md/bcache/io.c
View File

@ -25,7 +25,6 @@ struct bio *bch_bbio_alloc(struct cache_set *c)
struct bio *bio = &b->bio;
bio_init(bio);
bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
bio->bi_max_vecs = bucket_pages(c);
bio->bi_io_vec = bio->bi_inline_vecs;

2
include/linux/bio.h
View File

@ -715,8 +715,6 @@ static inline void bio_inc_remaining(struct bio *bio)
* and the bvec_slabs[].
*/
#define BIO_POOL_SIZE 2
#define BIOVEC_NR_POOLS 6
#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
struct bio_set {
struct kmem_cache *bio_slab;

22
include/linux/blk_types.h
View File

@ -134,19 +134,25 @@ struct bio {
/*
* Flags starting here get preserved by bio_reset() - this includes
* BIO_POOL_IDX()
* BVEC_POOL_IDX()
*/
#define BIO_RESET_BITS 13
#define BIO_OWNS_VEC 13 /* bio_free() should free bvec */
/*
* top 4 bits of bio flags indicate the pool this bio came from
* We support 6 different bvec pools, the last one is magic in that it
* is backed by a mempool.
*/
#define BIO_POOL_BITS (4)
#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
#define BIO_POOL_OFFSET (32 - BIO_POOL_BITS)
#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
#define BVEC_POOL_NR 6
#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
/*
* Top 4 bits of bio flags indicate the pool the bvecs came from. We add
* 1 to the actual index so that 0 indicates that there are no bvecs to be
* freed.
*/
#define BVEC_POOL_BITS (4)
#define BVEC_POOL_OFFSET (32 - BVEC_POOL_BITS)
#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
#endif /* CONFIG_BLOCK */