#define ZSWAP_PARAM_UNSET ""
+static int zswap_setup(void);
+
/* Enable/disable zswap */
static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON);
static int zswap_enabled_param_set(const char *,
/* 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
+};
+
+static enum zswap_init_type zswap_init_state;
-/* fatal error during init */
-static bool zswap_init_failed;
+/* used to ensure the integrity of initialization */
+static DEFINE_MUTEX(zswap_init_lock);
/* init completed, but couldn't create the initial pool */
static bool zswap_has_pool;
**********************************/
static struct kmem_cache *zswap_entry_cache;
-static int __init zswap_entry_cache_create(void)
-{
- zswap_entry_cache = KMEM_CACHE(zswap_entry, 0);
- return zswap_entry_cache == NULL;
-}
-
-static void __init zswap_entry_cache_destroy(void)
-{
- kmem_cache_destroy(zswap_entry_cache);
-}
-
static struct zswap_entry *zswap_entry_cache_alloc(gfp_t gfp)
{
struct zswap_entry *entry;
return NULL;
}
-static __init struct zswap_pool *__zswap_pool_create_fallback(void)
+static struct zswap_pool *__zswap_pool_create_fallback(void)
{
bool has_comp, has_zpool;
* param callbacks
**********************************/
+static bool zswap_pool_changed(const char *s, const struct kernel_param *kp)
+{
+ /* no change required */
+ if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool)
+ return false;
+ return true;
+}
+
/* val must be a null-terminated string */
static int __zswap_param_set(const char *val, const struct kernel_param *kp,
char *type, char *compressor)
{
struct zswap_pool *pool, *put_pool = NULL;
char *s = strstrip((char *)val);
- int ret;
-
- if (zswap_init_failed) {
+ int ret = 0;
+ bool new_pool = false;
+
+ mutex_lock(&zswap_init_lock);
+ 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.
+ */
+ ret = param_set_charp(s, kp);
+ break;
+ case ZSWAP_INIT_SUCCEED:
+ new_pool = zswap_pool_changed(s, kp);
+ break;
+ case ZSWAP_INIT_FAILED:
pr_err("can't set param, initialization failed\n");
- return -ENODEV;
+ ret = -ENODEV;
}
+ mutex_unlock(&zswap_init_lock);
- /* 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);
+ /* no need to create a new pool, return directly */
+ if (!new_pool)
+ return ret;
if (!type) {
if (!zpool_has_pool(s)) {
static int zswap_enabled_param_set(const char *val,
const struct kernel_param *kp)
{
- if (zswap_init_failed) {
+ int ret = -ENODEV;
+
+ /* if this is load-time (pre-init) param setting, only set param. */
+ if (system_state != SYSTEM_RUNNING)
+ return param_set_bool(val, kp);
+
+ mutex_lock(&zswap_init_lock);
+ switch (zswap_init_state) {
+ case ZSWAP_UNINIT:
+ if (zswap_setup())
+ break;
+ fallthrough;
+ case ZSWAP_INIT_SUCCEED:
+ if (!zswap_has_pool)
+ pr_err("can't enable, no pool configured\n");
+ else
+ ret = param_set_bool(val, kp);
+ break;
+ 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;
}
+ mutex_unlock(&zswap_init_lock);
- return param_set_bool(val, kp);
+ return ret;
}
/*********************************
static int zswap_is_page_same_filled(void *ptr, unsigned long *value)
{
- unsigned int pos;
unsigned long *page;
+ unsigned long val;
+ unsigned int pos, last_pos = PAGE_SIZE / sizeof(*page) - 1;
page = (unsigned long *)ptr;
- for (pos = 1; pos < PAGE_SIZE / sizeof(*page); pos++) {
- if (page[pos] != page[0])
+ val = page[0];
+
+ if (val != page[last_pos])
+ return 0;
+
+ for (pos = 1; pos < last_pos; pos++) {
+ if (val != page[pos])
return 0;
}
- *value = page[0];
+
+ *value = val;
+
return 1;
}
static struct dentry *zswap_debugfs_root;
-static int __init zswap_debugfs_init(void)
+static int zswap_debugfs_init(void)
{
if (!debugfs_initialized())
return -ENODEV;
return 0;
}
#else
-static int __init zswap_debugfs_init(void)
+static int zswap_debugfs_init(void)
{
return 0;
}
/*********************************
* module init and exit
**********************************/
-static int __init init_zswap(void)
+static int zswap_setup(void)
{
struct zswap_pool *pool;
int ret;
- zswap_init_started = true;
-
- if (zswap_entry_cache_create()) {
+ zswap_entry_cache = KMEM_CACHE(zswap_entry, 0);
+ if (!zswap_entry_cache) {
pr_err("entry cache creation failed\n");
goto cache_fail;
}
goto destroy_wq;
if (zswap_debugfs_init())
pr_warn("debugfs initialization failed\n");
+ zswap_init_state = ZSWAP_INIT_SUCCEED;
return 0;
destroy_wq:
hp_fail:
cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);
dstmem_fail:
- zswap_entry_cache_destroy();
+ 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;
}
+
+static int __init zswap_init(void)
+{
+ if (!zswap_enabled)
+ return 0;
+ return zswap_setup();
+}
/* must be late so crypto has time to come up */
-late_initcall(init_zswap);
+late_initcall(zswap_init);
MODULE_AUTHOR("Seth Jennings <sjennings@variantweb.net>");
MODULE_DESCRIPTION("Compressed cache for swap pages");
projects / linux-block.git / blobdiff