mm/zswap: replace zswap_init_{started/failed} with zswap_init_state

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}.

Link: https://lkml.kernel.org/r/20230403121318.1876082-3-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/zswap.c b/mm/zswap.c
index 6d2b879..9169c2b 100644 (file)
--- 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 @@ dstmem_fail:
        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;
 }