diff options
| -rw-r--r-- | mm/zswap.c | 142 |
1 files changed, 129 insertions, 13 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index f9ba9bb1c1b8..4043df7c672f 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -80,23 +80,39 @@ static u64 zswap_duplicate_entry; static bool zswap_enabled; module_param_named(enabled, zswap_enabled, bool, 0644); -/* Compressor to be used by zswap (fixed at boot for now) */ +/* Crypto compressor to use */ #define ZSWAP_COMPRESSOR_DEFAULT "lzo" -static char *zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT; -module_param_named(compressor, zswap_compressor, charp, 0444); - -/* The maximum percentage of memory that the compressed pool can occupy */ -static unsigned int zswap_max_pool_percent = 20; -module_param_named(max_pool_percent, - zswap_max_pool_percent, uint, 0644); +static char zswap_compressor[CRYPTO_MAX_ALG_NAME] = ZSWAP_COMPRESSOR_DEFAULT; +static struct kparam_string zswap_compressor_kparam = { + .string = zswap_compressor, + .maxlen = sizeof(zswap_compressor), +}; +static int zswap_compressor_param_set(const char *, + const struct kernel_param *); +static struct kernel_param_ops zswap_compressor_param_ops = { + .set = zswap_compressor_param_set, + .get = param_get_string, +}; +module_param_cb(compressor, &zswap_compressor_param_ops, + &zswap_compressor_kparam, 0644); -/* Compressed storage to use */ +/* Compressed storage zpool to use */ #define ZSWAP_ZPOOL_DEFAULT "zbud" -static char *zswap_zpool_type = ZSWAP_ZPOOL_DEFAULT; -module_param_named(zpool, zswap_zpool_type, charp, 0444); +static char zswap_zpool_type[32 /* arbitrary */] = ZSWAP_ZPOOL_DEFAULT; +static struct kparam_string zswap_zpool_kparam = { + .string = zswap_zpool_type, + .maxlen = sizeof(zswap_zpool_type), +}; +static int zswap_zpool_param_set(const char *, const struct kernel_param *); +static struct kernel_param_ops zswap_zpool_param_ops = { + .set = zswap_zpool_param_set, + .get = param_get_string, +}; +module_param_cb(zpool, &zswap_zpool_param_ops, &zswap_zpool_kparam, 0644); -/* zpool is shared by all of zswap backend */ -static struct zpool *zswap_pool; +/* The maximum percentage of memory that the compressed pool can occupy */ +static unsigned int zswap_max_pool_percent = 20; +module_param_named(max_pool_percent, zswap_max_pool_percent, uint, 0644); /********************************* * data structures @@ -161,6 +177,9 @@ static LIST_HEAD(zswap_pools); /* protects zswap_pools list modification */ static DEFINE_SPINLOCK(zswap_pools_lock); +/* used by param callback function */ +static bool zswap_init_started; + /********************************* * helpers and fwd declarations **********************************/ @@ -662,6 +681,101 @@ static void zswap_pool_put(struct zswap_pool *pool) } /********************************* +* param callbacks +**********************************/ + +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 str[kp->str->maxlen], *s; + int ret; + + /* + * kp is either zswap_zpool_kparam or zswap_compressor_kparam, defined + * at the top of this file, so maxlen is CRYPTO_MAX_ALG_NAME (64) or + * 32 (arbitrary). + */ + strlcpy(str, val, kp->str->maxlen); + s = strim(str); + + /* 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_copystring(s, kp); + + /* no change required */ + if (!strncmp(kp->str->string, s, kp->str->maxlen)) + return 0; + + if (!type) { + type = s; + if (!zpool_has_pool(type)) { + pr_err("zpool %s not available\n", type); + return -ENOENT; + } + } else if (!compressor) { + compressor = s; + if (!crypto_has_comp(compressor, 0, 0)) { + pr_err("compressor %s not available\n", compressor); + return -ENOENT; + } + } + + spin_lock(&zswap_pools_lock); + + pool = zswap_pool_find_get(type, compressor); + if (pool) { + zswap_pool_debug("using existing", pool); + list_del_rcu(&pool->list); + } else { + spin_unlock(&zswap_pools_lock); + pool = zswap_pool_create(type, compressor); + spin_lock(&zswap_pools_lock); + } + + if (pool) + ret = param_set_copystring(s, kp); + else + ret = -EINVAL; + + if (!ret) { + put_pool = zswap_pool_current(); + list_add_rcu(&pool->list, &zswap_pools); + } else if (pool) { + /* add the possibly pre-existing pool to the end of the pools + * list; if it's new (and empty) then it'll be removed and + * destroyed by the put after we drop the lock + */ + list_add_tail_rcu(&pool->list, &zswap_pools); + put_pool = pool; + } + + spin_unlock(&zswap_pools_lock); + + /* drop the ref from either the old current pool, + * or the new pool we failed to add + */ + if (put_pool) + zswap_pool_put(put_pool); + + return ret; +} + +static int zswap_compressor_param_set(const char *val, + const struct kernel_param *kp) +{ + return __zswap_param_set(val, kp, zswap_zpool_type, NULL); +} + +static int zswap_zpool_param_set(const char *val, + const struct kernel_param *kp) +{ + return __zswap_param_set(val, kp, NULL, zswap_compressor); +} + +/********************************* * writeback code **********************************/ /* return enum for zswap_get_swap_cache_page */ @@ -1114,6 +1228,8 @@ static int __init init_zswap(void) { struct zswap_pool *pool; + zswap_init_started = true; + if (zswap_entry_cache_create()) { pr_err("entry cache creation failed\n"); goto cache_fail; |