In preparation for implementing lockless slab shrink, we need to dynamically allocate the md-bcache shrinker, so that it can be freed asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU read-side critical section when releasing the struct cache_set. Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> --- drivers/md/bcache/bcache.h | 2 +- drivers/md/bcache/btree.c | 23 ++++++++++++++--------- drivers/md/bcache/sysfs.c | 2 +- 3 files changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 700dc5588d5f..53c73b372e7a 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -541,7 +541,7 @@ struct cache_set { struct bio_set bio_split; /* For the btree cache */ - struct shrinker shrink; + struct shrinker *shrink; /* For the btree cache and anything allocation related */ struct mutex bucket_lock; diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 569f48958bde..1131ae91f62a 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -667,7 +667,7 @@ static int mca_reap(struct btree *b, unsigned int min_order, bool flush) static unsigned long bch_mca_scan(struct shrinker *shrink, struct shrink_control *sc) { - struct cache_set *c = container_of(shrink, struct cache_set, shrink); + struct cache_set *c = shrink->private_data; struct btree *b, *t; unsigned long i, nr = sc->nr_to_scan; unsigned long freed = 0; @@ -734,7 +734,7 @@ static unsigned long bch_mca_scan(struct shrinker *shrink, static unsigned long bch_mca_count(struct shrinker *shrink, struct shrink_control *sc) { - struct cache_set *c = container_of(shrink, struct cache_set, shrink); + struct cache_set *c = shrink->private_data; if (c->shrinker_disabled) return 0; @@ -752,8 +752,8 @@ void bch_btree_cache_free(struct cache_set *c) closure_init_stack(&cl); - if (c->shrink.list.next) - unregister_shrinker(&c->shrink); + if (c->shrink->list.next) + unregister_and_free_shrinker(c->shrink); mutex_lock(&c->bucket_lock); @@ -828,14 +828,19 @@ int bch_btree_cache_alloc(struct cache_set *c) c->verify_data = NULL; #endif - c->shrink.count_objects = bch_mca_count; - c->shrink.scan_objects = bch_mca_scan; - c->shrink.seeks = 4; - c->shrink.batch = c->btree_pages * 2; + c->shrink = shrinker_alloc_and_init(bch_mca_count, bch_mca_scan, + c->btree_pages * 2, 4, 0, c); + if (!c->shrink) { + pr_warn("bcache: %s: could not allocate shrinker\n", + __func__); + return -ENOMEM; + } - if (register_shrinker(&c->shrink, "md-bcache:%pU", c->set_uuid)) + if (register_shrinker(c->shrink, "md-bcache:%pU", c->set_uuid)) { pr_warn("bcache: %s: could not register shrinker\n", __func__); + shrinker_free(c->shrink); + } return 0; } diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index c6f677059214..771577581f52 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -866,7 +866,7 @@ STORE(__bch_cache_set) sc.gfp_mask = GFP_KERNEL; sc.nr_to_scan = strtoul_or_return(buf); - c->shrink.scan_objects(&c->shrink, &sc); + c->shrink->scan_objects(c->shrink, &sc); } sysfs_strtoul_clamp(congested_read_threshold_us, -- 2.30.2