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authorChristoph Hellwig <hch@lst.de>2021-02-02 18:19:29 +0100
committerJens Axboe <axboe@kernel.dk>2021-02-08 08:33:16 -0700
commit7a800a20ae6329e803c5c646b20811a6ae9ca136 (patch)
tree9c72ec387e817945bde72c5b2e75e633688509c9 /block/bio.c
parent72b043654ba8b8ce2e0cf3da49247b2db3acb2c1 (diff)
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.c104
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++) {