mm: zswap: rename is_zswap_enabled() to zswap_is_enabled()

In preparation for introducing a similar function, rename
is_zswap_enabled() to use zswap_* prefix like other zswap functions.

Link: https://lkml.kernel.org/r/20240611024516.1375191-1-yosryahmed@google.comSigned-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/zswap.h

@@ -35,7 +35,7 @@ void zswap_swapoff(int type);
 void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg);
 void zswap_lruvec_state_init(struct lruvec *lruvec);
 void zswap_folio_swapin(struct folio *folio);
-bool is_zswap_enabled(void);
+bool zswap_is_enabled(void);
 #else
 
 struct zswap_lruvec_state {};
@@ -60,7 +60,7 @@ static inline void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) {}
 static inline void zswap_lruvec_state_init(struct lruvec *lruvec) {}
 static inline void zswap_folio_swapin(struct folio *folio) {}
 
-static inline bool is_zswap_enabled(void)
+static inline bool zswap_is_enabled(void)
 {
 	return false;
 }

mm/memcontrol.c

@@ -8434,7 +8434,7 @@ void obj_cgroup_uncharge_zswap(struct obj_cgroup *objcg, size_t size)
 bool mem_cgroup_zswap_writeback_enabled(struct mem_cgroup *memcg)
 {
 	/* if zswap is disabled, do not block pages going to the swapping device */
-	return !is_zswap_enabled() || !memcg || READ_ONCE(memcg->zswap_writeback);
+	return !zswap_is_enabled() || !memcg || READ_ONCE(memcg->zswap_writeback);
 }
 
 static u64 zswap_current_read(struct cgroup_subsys_state *css,

mm/zswap.c

@@ -131,7 +131,7 @@ static bool zswap_shrinker_enabled = IS_ENABLED(
 		CONFIG_ZSWAP_SHRINKER_DEFAULT_ON);
 module_param_named(shrinker_enabled, zswap_shrinker_enabled, bool, 0644);
 
-bool is_zswap_enabled(void)
+bool zswap_is_enabled(void)
 {
 	return zswap_enabled;
 }