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author | Christoph Hellwig <hch@lst.de> | 2021-02-02 18:19:29 +0100 |
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committer | Jens Axboe <axboe@kernel.dk> | 2021-02-08 08:33:16 -0700 |
commit | 7a800a20ae6329e803c5c646b20811a6ae9ca136 (patch) | |
tree | 9c72ec387e817945bde72c5b2e75e633688509c9 /block/bio.c | |
parent | 72b043654ba8b8ce2e0cf3da49247b2db3acb2c1 (diff) | |
download | linux-7a800a20ae6329e803c5c646b20811a6ae9ca136.tar.gz linux-7a800a20ae6329e803c5c646b20811a6ae9ca136.tar.bz2 linux-7a800a20ae6329e803c5c646b20811a6ae9ca136.zip |
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 <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r-- | block/bio.c | 104 |
1 files changed, 43 insertions, 61 deletions
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++) { |