The inline bvecs won't be used if user needn't bvecs by not passing BIOSET_NEED_BVECS, so don't allocate bvecs in this situation. Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- block/bio.c | 7 +++++-- include/linux/bio.h | 1 + 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/block/bio.c b/block/bio.c index cfa0e9db30e0..496aa5938f79 100644 --- a/block/bio.c +++ b/block/bio.c @@ -89,8 +89,7 @@ static struct bio_slab *create_bio_slab(unsigned int size) static inline unsigned int bs_bio_slab_size(struct bio_set *bs) { - return bs->front_pad + sizeof(struct bio) + - BIO_INLINE_VECS * sizeof(struct bio_vec); + return bs->front_pad + sizeof(struct bio) + bs->back_pad; } static struct kmem_cache *bio_find_or_create_slab(struct bio_set *bs) @@ -1572,6 +1571,10 @@ int bioset_init(struct bio_set *bs, int flags) { bs->front_pad = front_pad; + if (flags & BIOSET_NEED_BVECS) + bs->back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); + else + bs->back_pad = 0; spin_lock_init(&bs->rescue_lock); bio_list_init(&bs->rescue_list); diff --git a/include/linux/bio.h b/include/linux/bio.h index 1edda614f7ce..f606eb1e556f 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -703,6 +703,7 @@ struct bio_set { mempool_t bvec_integrity_pool; #endif + unsigned int back_pad; /* * Deadlock avoidance for stacking block drivers: see comments in * bio_alloc_bioset() for details -- 2.28.0