mm: zswap: function ordering: zswap_pools

Move the operations against the global zswap_pools list (current pool,
last, find) to the pool section.

Link: https://lkml.kernel.org/r/20240130014208.565554-13-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>

diff --git a/mm/zswap.c b/mm/zswap.c
index 6f4e1c22a0dec2f4a063f3dc88218fd234f1787a..77104406649b054a7e4ed25b89fb4ecb79c9a3e8 100644 (file)
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -517,6 +517,79 @@ static void zswap_pool_put(struct zswap_pool *pool)
        kref_put(&pool->kref, __zswap_pool_empty);
 }
 
+static struct zswap_pool *__zswap_pool_current(void)
+{
+       struct zswap_pool *pool;
+
+       pool = list_first_or_null_rcu(&zswap_pools, typeof(*pool), list);
+       WARN_ONCE(!pool && zswap_has_pool,
+                 "%s: no page storage pool!\n", __func__);
+
+       return pool;
+}
+
+static struct zswap_pool *zswap_pool_current(void)
+{
+       assert_spin_locked(&zswap_pools_lock);
+
+       return __zswap_pool_current();
+}
+
+static struct zswap_pool *zswap_pool_current_get(void)
+{
+       struct zswap_pool *pool;
+
+       rcu_read_lock();
+
+       pool = __zswap_pool_current();
+       if (!zswap_pool_get(pool))
+               pool = NULL;
+
+       rcu_read_unlock();
+
+       return pool;
+}
+
+static struct zswap_pool *zswap_pool_last_get(void)
+{
+       struct zswap_pool *pool, *last = NULL;
+
+       rcu_read_lock();
+
+       list_for_each_entry_rcu(pool, &zswap_pools, list)
+               last = pool;
+       WARN_ONCE(!last && zswap_has_pool,
+                 "%s: no page storage pool!\n", __func__);
+       if (!zswap_pool_get(last))
+               last = NULL;
+
+       rcu_read_unlock();
+
+       return last;
+}
+
+/* type and compressor must be null-terminated */
+static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
+{
+       struct zswap_pool *pool;
+
+       assert_spin_locked(&zswap_pools_lock);
+
+       list_for_each_entry_rcu(pool, &zswap_pools, list) {
+               if (strcmp(pool->tfm_name, compressor))
+                       continue;
+               /* all zpools share the same type */
+               if (strcmp(zpool_get_type(pool->zpools[0]), type))
+                       continue;
+               /* if we can't get it, it's about to be destroyed */
+               if (!zswap_pool_get(pool))
+                       continue;
+               return pool;
+       }
+
+       return NULL;
+}
+
 /* should be called under RCU */
 #ifdef CONFIG_MEMCG
 static inline struct mem_cgroup *mem_cgroup_from_entry(struct zswap_entry *entry)
@@ -937,83 +1010,6 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node)
        return 0;
 }
 
-/*********************************
-* pool functions
-**********************************/
-
-static struct zswap_pool *__zswap_pool_current(void)
-{
-       struct zswap_pool *pool;
-
-       pool = list_first_or_null_rcu(&zswap_pools, typeof(*pool), list);
-       WARN_ONCE(!pool && zswap_has_pool,
-                 "%s: no page storage pool!\n", __func__);
-
-       return pool;
-}
-
-static struct zswap_pool *zswap_pool_current(void)
-{
-       assert_spin_locked(&zswap_pools_lock);
-
-       return __zswap_pool_current();
-}
-
-static struct zswap_pool *zswap_pool_current_get(void)
-{
-       struct zswap_pool *pool;
-
-       rcu_read_lock();
-
-       pool = __zswap_pool_current();
-       if (!zswap_pool_get(pool))
-               pool = NULL;
-
-       rcu_read_unlock();
-
-       return pool;
-}
-
-static struct zswap_pool *zswap_pool_last_get(void)
-{
-       struct zswap_pool *pool, *last = NULL;
-
-       rcu_read_lock();
-
-       list_for_each_entry_rcu(pool, &zswap_pools, list)
-               last = pool;
-       WARN_ONCE(!last && zswap_has_pool,
-                 "%s: no page storage pool!\n", __func__);
-       if (!zswap_pool_get(last))
-               last = NULL;
-
-       rcu_read_unlock();
-
-       return last;
-}
-
-/* type and compressor must be null-terminated */
-static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
-{
-       struct zswap_pool *pool;
-
-       assert_spin_locked(&zswap_pools_lock);
-
-       list_for_each_entry_rcu(pool, &zswap_pools, list) {
-               if (strcmp(pool->tfm_name, compressor))
-                       continue;
-               /* all zpools share the same type */
-               if (strcmp(zpool_get_type(pool->zpools[0]), type))
-                       continue;
-               /* if we can't get it, it's about to be destroyed */
-               if (!zswap_pool_get(pool))
-                       continue;
-               return pool;
-       }
-
-       return NULL;
-}
-
 static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_one *l,
                                       spinlock_t *lock, void *arg)
 {