diff options
Diffstat (limited to 'mm/zswap.c')
| -rw-r--r-- | mm/zswap.c | 138 |
1 files changed, 89 insertions, 49 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index f2fc0373b967..e1e621d0b6a0 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -81,6 +81,8 @@ static bool zswap_pool_reached_full; #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 *, @@ -214,11 +216,16 @@ 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 +}; + +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; @@ -272,17 +279,6 @@ static void zswap_update_total_size(void) **********************************/ 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; @@ -663,7 +659,7 @@ error: 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; @@ -764,28 +760,43 @@ static void zswap_pool_put(struct zswap_pool *pool) * 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)) { @@ -875,16 +886,30 @@ 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) { + 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; } /********************************* @@ -1073,15 +1098,23 @@ fail: 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; } @@ -1434,7 +1467,7 @@ static const struct frontswap_ops zswap_frontswap_ops = { static struct dentry *zswap_debugfs_root; -static int __init zswap_debugfs_init(void) +static int zswap_debugfs_init(void) { if (!debugfs_initialized()) return -ENODEV; @@ -1465,7 +1498,7 @@ static int __init zswap_debugfs_init(void) return 0; } #else -static int __init zswap_debugfs_init(void) +static int zswap_debugfs_init(void) { return 0; } @@ -1474,14 +1507,13 @@ static int __init zswap_debugfs_init(void) /********************************* * 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; } @@ -1520,6 +1552,7 @@ 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: @@ -1530,15 +1563,22 @@ fallback_fail: 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"); |