mm: zswap: function ordering: pool refcounting

Move pool refcounting functions into the pool section. First the
destroy functions, then the get and put which uses them.

__zswap_pool_empty() has an upward reference to the global
zswap_pools, to sanity check it's not the currently active pool that's
being freed. That gets the forward decl for zswap_pool_current().

This puts the get and put function above all callers, so kill the
forward decls as well.

Link: https://lkml.kernel.org/r/20240130014208.565554-12-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2024-01-29 20:36:47 -05:00 committed by Andrew Morton
parent a984649b5c
commit 39f3ec8eaa

View file

@ -278,8 +278,6 @@ static inline struct zswap_tree *swap_zswap_tree(swp_entry_t swp)
static int zswap_writeback_entry(struct zswap_entry *entry,
swp_entry_t swpentry);
static int zswap_pool_get(struct zswap_pool *pool);
static void zswap_pool_put(struct zswap_pool *pool);
static bool zswap_is_full(void)
{
@ -472,6 +470,53 @@ static void zswap_pool_destroy(struct zswap_pool *pool)
kfree(pool);
}
static void __zswap_pool_release(struct work_struct *work)
{
struct zswap_pool *pool = container_of(work, typeof(*pool),
release_work);
synchronize_rcu();
/* nobody should have been able to get a kref... */
WARN_ON(kref_get_unless_zero(&pool->kref));
/* pool is now off zswap_pools list and has no references. */
zswap_pool_destroy(pool);
}
static struct zswap_pool *zswap_pool_current(void);
static void __zswap_pool_empty(struct kref *kref)
{
struct zswap_pool *pool;
pool = container_of(kref, typeof(*pool), kref);
spin_lock(&zswap_pools_lock);
WARN_ON(pool == zswap_pool_current());
list_del_rcu(&pool->list);
INIT_WORK(&pool->release_work, __zswap_pool_release);
schedule_work(&pool->release_work);
spin_unlock(&zswap_pools_lock);
}
static int __must_check zswap_pool_get(struct zswap_pool *pool)
{
if (!pool)
return 0;
return kref_get_unless_zero(&pool->kref);
}
static void zswap_pool_put(struct zswap_pool *pool)
{
kref_put(&pool->kref, __zswap_pool_empty);
}
/* should be called under RCU */
#ifdef CONFIG_MEMCG
static inline struct mem_cgroup *mem_cgroup_from_entry(struct zswap_entry *entry)
@ -1121,51 +1166,6 @@ static void shrink_worker(struct work_struct *w)
zswap_pool_put(pool);
}
static int __must_check zswap_pool_get(struct zswap_pool *pool)
{
if (!pool)
return 0;
return kref_get_unless_zero(&pool->kref);
}
static void __zswap_pool_release(struct work_struct *work)
{
struct zswap_pool *pool = container_of(work, typeof(*pool),
release_work);
synchronize_rcu();
/* nobody should have been able to get a kref... */
WARN_ON(kref_get_unless_zero(&pool->kref));
/* pool is now off zswap_pools list and has no references. */
zswap_pool_destroy(pool);
}
static void __zswap_pool_empty(struct kref *kref)
{
struct zswap_pool *pool;
pool = container_of(kref, typeof(*pool), kref);
spin_lock(&zswap_pools_lock);
WARN_ON(pool == zswap_pool_current());
list_del_rcu(&pool->list);
INIT_WORK(&pool->release_work, __zswap_pool_release);
schedule_work(&pool->release_work);
spin_unlock(&zswap_pools_lock);
}
static void zswap_pool_put(struct zswap_pool *pool)
{
kref_put(&pool->kref, __zswap_pool_empty);
}
/*********************************
* param callbacks
**********************************/