[PATCH -next v9 2/3] mm/zswap: replace zswap_init_{started/failed} with zswap_init_state

Liu Shixin
2023-04-11T08:46:38Z

The zswap_init_started variable name has a bit confusing. Actually, there
are three state: uninitialized, initial failed and initial succeed. Add
a new variable zswap_init_state to replace zswap_init_{started/failed}.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
mm/zswap.c | 55 +++++++++++++++++++++++++++++-------------------------
1 file changed, 30 insertions(+), 25 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index 6d2b879f091e..9169c2baee87 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -214,11 +214,13 @@ static DEFINE_SPINLOCK(zswap_pools_lock);
/* pool counter to provide unique names to zpool */
static atomic_t zswap_pools_count = ATOMIC_INIT(0);

-/* used by param callback function */
-static bool zswap_init_started;
+enum zswap_init_type {
+ ZSWAP_UNINIT,
+ ZSWAP_INIT_SUCCEED,
+ ZSWAP_INIT_FAILED
+};

-/* fatal error during init */
-static bool zswap_init_failed;
+static enum zswap_init_type zswap_init_state;

/* init completed, but couldn't create the initial pool */
static bool zswap_has_pool;
@@ -761,21 +763,22 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
char *s = strstrip((char *)val);
int ret;

- if (zswap_init_failed) {
+ switch (zswap_init_state) {
+ case ZSWAP_UNINIT:
+ /* if this is load-time (pre-init) param setting,
+ * don't create a pool; that's done during init.
+ */
+ return param_set_charp(s, kp);
+ case ZSWAP_INIT_SUCCEED:
+ /* no change required */
+ if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool)
+ return 0;
+ break;
+ case ZSWAP_INIT_FAILED:
pr_err("can't set param, initialization failed\n");
return -ENODEV;
}

- /* no change required */
- if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool)
- return 0;
-
- /* if this is load-time (pre-init) param setting,
- * don't create a pool; that's done during init.
- */
- if (!zswap_init_started)
- return param_set_charp(s, kp);
-
if (!type) {
if (!zpool_has_pool(s)) {
pr_err("zpool %s not available\n", s);
@@ -864,16 +867,19 @@ static int zswap_zpool_param_set(const char *val,
static int zswap_enabled_param_set(const char *val,
const struct kernel_param *kp)
{
- if (zswap_init_failed) {
+ switch (zswap_init_state) {
+ case ZSWAP_UNINIT:
+ return param_set_bool(val, kp);
+ case ZSWAP_INIT_SUCCEED:
+ if (!zswap_has_pool) {
+ pr_err("can't enable, no pool configured\n");
+ return -ENODEV;
+ } else
+ return param_set_bool(val, kp);
+ case ZSWAP_INIT_FAILED:
pr_err("can't enable, initialization failed\n");
return -ENODEV;
}
- if (!zswap_has_pool && zswap_init_started) {
- pr_err("can't enable, no pool configured\n");
- return -ENODEV;
- }
-
- return param_set_bool(val, kp);
}

/*********************************
@@ -1476,8 +1482,6 @@ static int __init init_zswap(void)
struct zswap_pool *pool;
int ret;

- zswap_init_started = true;
-
zswap_entry_cache = KMEM_CACHE(zswap_entry, 0);
if (!zswap_entry_cache) {
pr_err("entry cache creation failed\n");
@@ -1518,6 +1522,7 @@ static int __init init_zswap(void)
goto destroy_wq;
if (zswap_debugfs_init())
pr_warn("debugfs initialization failed\n");
+ zswap_init_state = ZSWAP_INIT_SUCCEED;
return 0;

destroy_wq:
@@ -1531,7 +1536,7 @@ static int __init init_zswap(void)
kmem_cache_destroy(zswap_entry_cache);
cache_fail:
/* if built-in, we aren't unloaded on failure; don't allow use */
- zswap_init_failed = true;
+ zswap_init_state = ZSWAP_INIT_FAILED;
zswap_enabled = false;
return -ENOMEM;
}
--
2.25.1