* tunables
**********************************/
+#define ZSWAP_PARAM_UNSET ""
+
/* Enable/disable zswap (disabled by default) */
static bool zswap_enabled;
static int zswap_enabled_param_set(const char *,
/* fatal error during init */
static bool zswap_init_failed;
+/* init completed, but couldn't create the initial pool */
+static bool zswap_has_pool;
+
/*********************************
* helpers and fwd declarations
**********************************/
u8 *dst;
dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
- if (!dst) {
- pr_err("can't allocate compressor buffer\n");
+ if (!dst)
return -ENOMEM;
- }
+
per_cpu(zswap_dstmem, cpu) = dst;
return 0;
}
struct zswap_pool *pool;
pool = list_first_or_null_rcu(&zswap_pools, typeof(*pool), list);
- WARN_ON(!pool);
+ WARN_ONCE(!pool && zswap_has_pool,
+ "%s: no page storage pool!\n", __func__);
return pool;
}
rcu_read_lock();
pool = __zswap_pool_current();
- if (!pool || !zswap_pool_get(pool))
+ if (!zswap_pool_get(pool))
pool = NULL;
rcu_read_unlock();
list_for_each_entry_rcu(pool, &zswap_pools, list)
last = pool;
- if (!WARN_ON(!last) && !zswap_pool_get(last))
+ WARN_ONCE(!last && zswap_has_pool,
+ "%s: no page storage pool!\n", __func__);
+ if (!zswap_pool_get(last))
last = NULL;
rcu_read_unlock();
gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
int ret;
+ if (!zswap_has_pool) {
+ /* if either are unset, pool initialization failed, and we
+ * need both params to be set correctly before trying to
+ * create a pool.
+ */
+ if (!strcmp(type, ZSWAP_PARAM_UNSET))
+ return NULL;
+ if (!strcmp(compressor, ZSWAP_PARAM_UNSET))
+ return NULL;
+ }
+
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
- if (!pool) {
- pr_err("pool alloc failed\n");
+ if (!pool)
return NULL;
- }
/* unique name for each pool specifically required by zsmalloc */
snprintf(name, 38, "zswap%x", atomic_inc_return(&zswap_pools_count));
static __init struct zswap_pool *__zswap_pool_create_fallback(void)
{
- if (!crypto_has_comp(zswap_compressor, 0, 0)) {
- if (!strcmp(zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT)) {
- pr_err("default compressor %s not available\n",
- zswap_compressor);
- return NULL;
- }
+ bool has_comp, has_zpool;
+
+ has_comp = crypto_has_comp(zswap_compressor, 0, 0);
+ if (!has_comp && strcmp(zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT)) {
pr_err("compressor %s not available, using default %s\n",
zswap_compressor, ZSWAP_COMPRESSOR_DEFAULT);
param_free_charp(&zswap_compressor);
zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
+ has_comp = crypto_has_comp(zswap_compressor, 0, 0);
}
- if (!zpool_has_pool(zswap_zpool_type)) {
- if (!strcmp(zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT)) {
- pr_err("default zpool %s not available\n",
- zswap_zpool_type);
- return NULL;
- }
+ if (!has_comp) {
+ pr_err("default compressor %s not available\n",
+ zswap_compressor);
+ param_free_charp(&zswap_compressor);
+ zswap_compressor = ZSWAP_PARAM_UNSET;
+ }
+
+ has_zpool = zpool_has_pool(zswap_zpool_type);
+ if (!has_zpool && strcmp(zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT)) {
pr_err("zpool %s not available, using default %s\n",
zswap_zpool_type, ZSWAP_ZPOOL_DEFAULT);
param_free_charp(&zswap_zpool_type);
zswap_zpool_type = ZSWAP_ZPOOL_DEFAULT;
+ has_zpool = zpool_has_pool(zswap_zpool_type);
}
+ if (!has_zpool) {
+ pr_err("default zpool %s not available\n",
+ zswap_zpool_type);
+ param_free_charp(&zswap_zpool_type);
+ zswap_zpool_type = ZSWAP_PARAM_UNSET;
+ }
+
+ if (!has_comp || !has_zpool)
+ return NULL;
return zswap_pool_create(zswap_zpool_type, zswap_compressor);
}
static int __must_check zswap_pool_get(struct zswap_pool *pool)
{
+ if (!pool)
+ return 0;
+
return kref_get_unless_zero(&pool->kref);
}
}
/* no change required */
- if (!strcmp(s, *(char **)kp->arg))
+ if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool)
return 0;
/* if this is load-time (pre-init) param setting,
pool = zswap_pool_find_get(type, compressor);
if (pool) {
zswap_pool_debug("using existing", pool);
+ WARN_ON(pool == zswap_pool_current());
list_del_rcu(&pool->list);
- } else {
- spin_unlock(&zswap_pools_lock);
- pool = zswap_pool_create(type, compressor);
- spin_lock(&zswap_pools_lock);
}
+ spin_unlock(&zswap_pools_lock);
+
+ if (!pool)
+ pool = zswap_pool_create(type, compressor);
+
if (pool)
ret = param_set_charp(s, kp);
else
ret = -EINVAL;
+ spin_lock(&zswap_pools_lock);
+
if (!ret) {
put_pool = zswap_pool_current();
list_add_rcu(&pool->list, &zswap_pools);
+ zswap_has_pool = true;
} 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
spin_unlock(&zswap_pools_lock);
+ if (!zswap_has_pool && !pool) {
+ /* if initial pool creation failed, and this pool creation also
+ * failed, maybe both compressor and zpool params were bad.
+ * Allow changing this param, so pool creation will succeed
+ * when the other param is changed. We already verified this
+ * param is ok in the zpool_has_pool() or crypto_has_comp()
+ * checks above.
+ */
+ ret = param_set_charp(s, kp);
+ }
+
/* drop the ref from either the old current pool,
* or the new pool we failed to add
*/
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);
}
{
struct zswap_tree *tree;
- tree = kzalloc(sizeof(struct zswap_tree), GFP_KERNEL);
+ tree = kzalloc(sizeof(*tree), GFP_KERNEL);
if (!tree) {
pr_err("alloc failed, zswap disabled for swap type %d\n", type);
return;
goto hp_fail;
pool = __zswap_pool_create_fallback();
- if (!pool) {
+ if (pool) {
+ pr_info("loaded using pool %s/%s\n", pool->tfm_name,
+ zpool_get_type(pool->zpool));
+ list_add(&pool->list, &zswap_pools);
+ zswap_has_pool = true;
+ } else {
pr_err("pool creation failed\n");
- goto pool_fail;
+ zswap_enabled = false;
}
- pr_info("loaded using pool %s/%s\n", pool->tfm_name,
- zpool_get_type(pool->zpool));
-
- list_add(&pool->list, &zswap_pools);
frontswap_register_ops(&zswap_frontswap_ops);
if (zswap_debugfs_init())
pr_warn("debugfs initialization failed\n");
return 0;
-pool_fail:
- cpuhp_remove_state_nocalls(CPUHP_MM_ZSWP_POOL_PREPARE);
hp_fail:
cpuhp_remove_state(CPUHP_MM_ZSWP_MEM_PREPARE);
dstmem_fail:
projects / karo-tx-linux.git / blobdiff