From 7a800a20ae6329e803c5c646b20811a6ae9ca136 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 2 Feb 2021 18:19:29 +0100 Subject: block: use bi_max_vecs to find the bvec pool Instead of encoding of the bvec pool using magic bio flags, just use a helper to find the pool based on the max_vecs value. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/bio-integrity.c | 11 ++--- block/bio.c | 104 +++++++++++++++++++--------------------------- block/blk.h | 6 +-- include/linux/bio.h | 1 - include/linux/blk_types.h | 29 +------------ 5 files changed, 51 insertions(+), 100 deletions(-) diff --git a/block/bio-integrity.c b/block/bio-integrity.c index 19617fa326c3..dfa652122a2d 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -28,7 +28,7 @@ static void __bio_integrity_free(struct bio_set *bs, if (bs && mempool_initialized(&bs->bio_integrity_pool)) { if (bip->bip_vec) bvec_free(&bs->bvec_integrity_pool, bip->bip_vec, - bip->bip_slab); + bip->bip_max_vcnt); mempool_free(bip, &bs->bio_integrity_pool); } else { kfree(bip); @@ -70,14 +70,11 @@ 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); + bip->bip_max_vcnt = nr_vecs; + bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool, + &bip->bip_max_vcnt, gfp_mask); 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; diff --git a/block/bio.c b/block/bio.c index a36f955cd120..a0eabe2f8b07 100644 --- a/block/bio.c +++ b/block/bio.c @@ -36,6 +36,24 @@ static struct biovec_slab { { .nr_vecs = BIO_MAX_PAGES, .name = "biovec-max" }, }; +static struct biovec_slab *biovec_slab(unsigned short nr_vecs) +{ + switch (nr_vecs) { + /* smaller bios use inline vecs */ + case 5 ... 16: + return &bvec_slabs[0]; + case 17 ... 64: + return &bvec_slabs[1]; + case 65 ... 128: + return &bvec_slabs[2]; + case 129 ... BIO_MAX_PAGES: + return &bvec_slabs[3]; + default: + BUG(); + return NULL; + } +} + /* * fs_bio_set is the bio_set containing bio and iovec memory pools used by * IO code that does not need private memory pools. @@ -131,26 +149,14 @@ out: mutex_unlock(&bio_slab_lock); } -unsigned int bvec_nr_vecs(unsigned short idx) +void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs) { - return bvec_slabs[--idx].nr_vecs; -} + BIO_BUG_ON(nr_vecs > BIO_MAX_PAGES); -void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx) -{ - if (!idx) - return; - idx--; - - BIO_BUG_ON(idx >= BVEC_POOL_NR); - - if (idx == BVEC_POOL_MAX) { + if (nr_vecs == BIO_MAX_PAGES) mempool_free(bv, pool); - } else { - struct biovec_slab *bvs = bvec_slabs + idx; - - kmem_cache_free(bvs->slab, bv); - } + else if (nr_vecs > BIO_INLINE_VECS) + kmem_cache_free(biovec_slab(nr_vecs)->slab, bv); } /* @@ -163,48 +169,34 @@ static inline gfp_t bvec_alloc_gfp(gfp_t gfp) __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; } -struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx, - mempool_t *pool) +struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs, + gfp_t gfp_mask) { + struct biovec_slab *bvs = biovec_slab(*nr_vecs); + + if (WARN_ON_ONCE(!bvs)) + return NULL; + /* - * see comment near bvec_array define! + * Upgrade the nr_vecs request to take full advantage of the allocation. + * We also rely on this in the bvec_free path. */ - switch (nr) { - /* smaller bios use inline vecs */ - case 5 ... 16: - *idx = 2; - break; - case 17 ... 64: - *idx = 3; - break; - case 65 ... 128: - *idx = 4; - break; - case 129 ... BIO_MAX_PAGES: - *idx = 5; - break; - default: - return NULL; - } + *nr_vecs = bvs->nr_vecs; /* * Try a slab allocation first for all smaller allocations. If that * fails and __GFP_DIRECT_RECLAIM is set retry with the mempool. * The mempool is sized to handle up to BIO_MAX_PAGES entries. */ - if (*idx < BVEC_POOL_MAX) { - struct biovec_slab *bvs = bvec_slabs + *idx; + if (*nr_vecs < BIO_MAX_PAGES) { struct bio_vec *bvl; bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask)); - if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) { - (*idx)++; + if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) return bvl; - } - *idx = BVEC_POOL_MAX; + *nr_vecs = BIO_MAX_PAGES; } - (*idx)++; return mempool_alloc(pool, gfp_mask); } @@ -231,7 +223,7 @@ static void bio_free(struct bio *bio) bio_uninit(bio); if (bs) { - bvec_free(&bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio)); + bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs); /* * If we have front padding, adjust the bio pointer before freeing @@ -275,12 +267,8 @@ EXPORT_SYMBOL(bio_init); */ void bio_reset(struct bio *bio) { - unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS); - bio_uninit(bio); - memset(bio, 0, BIO_RESET_BYTES); - bio->bi_flags = flags; atomic_set(&bio->__bi_remaining, 1); } EXPORT_SYMBOL(bio_reset); @@ -453,22 +441,18 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned short nr_iovecs, bio = p + bs->front_pad; if (nr_iovecs > BIO_INLINE_VECS) { - unsigned long idx = 0; struct bio_vec *bvl = NULL; - bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool); + bvl = bvec_alloc(&bs->bvec_pool, &nr_iovecs, gfp_mask); if (!bvl && gfp_mask != saved_gfp) { punt_bios_to_rescuer(bs); gfp_mask = saved_gfp; - bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, - &bs->bvec_pool); + bvl = bvec_alloc(&bs->bvec_pool, &nr_iovecs, gfp_mask); } - if (unlikely(!bvl)) goto err_free; - bio_init(bio, bvl, bvec_nr_vecs(idx)); - bio->bi_flags |= idx << BVEC_POOL_OFFSET; + bio_init(bio, bvl, nr_iovecs); } else if (nr_iovecs) { bio_init(bio, bio->bi_inline_vecs, BIO_INLINE_VECS); } else { @@ -644,7 +628,7 @@ EXPORT_SYMBOL(bio_put); */ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) { - BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio)); + WARN_ON_ONCE(bio->bi_pool && bio->bi_max_vecs); /* * most users will be overriding ->bi_bdev with a new target, @@ -934,7 +918,7 @@ EXPORT_SYMBOL_GPL(bio_release_pages); static int bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) { - WARN_ON_ONCE(BVEC_POOL_IDX(bio) != 0); + WARN_ON_ONCE(bio->bi_max_vecs); bio->bi_vcnt = iter->nr_segs; bio->bi_io_vec = (struct bio_vec *)iter->bvec; @@ -1495,7 +1479,7 @@ EXPORT_SYMBOL_GPL(bio_trim); */ int biovec_init_pool(mempool_t *pool, int pool_entries) { - struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX; + struct biovec_slab *bp = bvec_slabs + ARRAY_SIZE(bvec_slabs) - 1; return mempool_init_slab_pool(pool, pool_entries, bp->slab); } @@ -1605,8 +1589,6 @@ static int __init init_bio(void) { int i; - BUILD_BUG_ON(BIO_FLAG_LAST > BVEC_POOL_OFFSET); - bio_integrity_init(); for (i = 0; i < ARRAY_SIZE(bvec_slabs); i++) { diff --git a/block/blk.h b/block/blk.h index e022a0d0f2ce..bfc4d526f626 100644 --- a/block/blk.h +++ b/block/blk.h @@ -56,9 +56,9 @@ void blk_free_flush_queue(struct blk_flush_queue *q); void blk_freeze_queue(struct request_queue *q); #define BIO_INLINE_VECS 4 -struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *); -void bvec_free(mempool_t *, struct bio_vec *, unsigned int); -unsigned int bvec_nr_vecs(unsigned short idx); +struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs, + gfp_t gfp_mask); +void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs); static inline bool biovec_phys_mergeable(struct request_queue *q, struct bio_vec *vec1, struct bio_vec *vec2) diff --git a/include/linux/bio.h b/include/linux/bio.h index 9ceeb8ecdb7f..3cbbaf76906e 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -329,7 +329,6 @@ struct bio_integrity_payload { struct bvec_iter bip_iter; - unsigned short bip_slab; /* slab the bip came from */ unsigned short bip_vcnt; /* # of integrity bio_vecs */ unsigned short bip_max_vcnt; /* integrity bio_vec slots */ unsigned short bip_flags; /* control flags */ diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 1bc6f6a01070..db026b6ec15a 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -227,7 +227,7 @@ struct bio { * top bits REQ_OP. Use * accessors. */ - unsigned short bi_flags; /* status, etc and bvec pool number */ + unsigned short bi_flags; /* BIO_* below */ unsigned short bi_ioprio; unsigned short bi_write_hint; blk_status_t bi_status; @@ -307,33 +307,6 @@ enum { BIO_FLAG_LAST }; -/* See BVEC_POOL_OFFSET below before adding new flags */ - -/* - * We support 6 different bvec pools, the last one is magic in that it - * is backed by a mempool. - */ -#define BVEC_POOL_NR 6 -#define BVEC_POOL_MAX (BVEC_POOL_NR - 1) - -/* - * Top 3 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 (3) -#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS) -#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET) -#if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1) -# error "BVEC_POOL_BITS is too small" -#endif - -/* - * Flags starting here get preserved by bio_reset() - this includes - * only BVEC_POOL_IDX() - */ -#define BIO_RESET_BITS BVEC_POOL_OFFSET - typedef __u32 __bitwise blk_mq_req_flags_t; /* -- cgit v1.2.3