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-rw-r--r--fs/super.c9
-rw-r--r--include/linux/shrinker.h7
-rw-r--r--mm/vmscan.c21
3 files changed, 29 insertions, 8 deletions
diff --git a/fs/super.c b/fs/super.c
index 5fa9a8d8d865..122c402049a2 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -167,6 +167,7 @@ static void destroy_unused_super(struct super_block *s)
security_sb_free(s);
put_user_ns(s->s_user_ns);
kfree(s->s_subtype);
+ free_prealloced_shrinker(&s->s_shrink);
/* no delays needed */
destroy_super_work(&s->destroy_work);
}
@@ -252,6 +253,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
s->s_shrink.count_objects = super_cache_count;
s->s_shrink.batch = 1024;
s->s_shrink.flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE;
+ if (prealloc_shrinker(&s->s_shrink))
+ goto fail;
return s;
fail:
@@ -518,11 +521,7 @@ retry:
hlist_add_head(&s->s_instances, &type->fs_supers);
spin_unlock(&sb_lock);
get_filesystem(type);
- err = register_shrinker(&s->s_shrink);
- if (err) {
- deactivate_locked_super(s);
- s = ERR_PTR(err);
- }
+ register_shrinker_prepared(&s->s_shrink);
return s;
}
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 388ff2936a87..6794490f25b2 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -75,6 +75,9 @@ struct shrinker {
#define SHRINKER_NUMA_AWARE (1 << 0)
#define SHRINKER_MEMCG_AWARE (1 << 1)
-extern int register_shrinker(struct shrinker *);
-extern void unregister_shrinker(struct shrinker *);
+extern int prealloc_shrinker(struct shrinker *shrinker);
+extern void register_shrinker_prepared(struct shrinker *shrinker);
+extern int register_shrinker(struct shrinker *shrinker);
+extern void unregister_shrinker(struct shrinker *shrinker);
+extern void free_prealloced_shrinker(struct shrinker *shrinker);
#endif
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 8b920ce3ae02..9b697323a88c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -303,7 +303,7 @@ unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone
/*
* Add a shrinker callback to be called from the vm.
*/
-int register_shrinker(struct shrinker *shrinker)
+int prealloc_shrinker(struct shrinker *shrinker)
{
size_t size = sizeof(*shrinker->nr_deferred);
@@ -313,10 +313,29 @@ int register_shrinker(struct shrinker *shrinker)
shrinker->nr_deferred = kzalloc(size, GFP_KERNEL);
if (!shrinker->nr_deferred)
return -ENOMEM;
+ return 0;
+}
+
+void free_prealloced_shrinker(struct shrinker *shrinker)
+{
+ kfree(shrinker->nr_deferred);
+ shrinker->nr_deferred = NULL;
+}
+void register_shrinker_prepared(struct shrinker *shrinker)
+{
down_write(&shrinker_rwsem);
list_add_tail(&shrinker->list, &shrinker_list);
up_write(&shrinker_rwsem);
+}
+
+int register_shrinker(struct shrinker *shrinker)
+{
+ int err = prealloc_shrinker(shrinker);
+
+ if (err)
+ return err;
+ register_shrinker_prepared(shrinker);
return 0;
}
EXPORT_SYMBOL(register_shrinker);