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Diffstat (limited to 'mm/zswap.c')
-rw-r--r--mm/zswap.c109
1 files changed, 81 insertions, 28 deletions
diff --git a/mm/zswap.c b/mm/zswap.c
index cabf09e0128b..eedc27894b10 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -76,6 +76,8 @@ static u64 zswap_duplicate_entry;
* tunables
**********************************/
+#define ZSWAP_PARAM_UNSET ""
+
/* Enable/disable zswap (disabled by default) */
static bool zswap_enabled;
static int zswap_enabled_param_set(const char *,
@@ -185,6 +187,9 @@ static bool zswap_init_started;
/* 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
**********************************/
@@ -424,7 +429,8 @@ static struct zswap_pool *__zswap_pool_current(void)
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;
}
@@ -443,7 +449,7 @@ static struct zswap_pool *zswap_pool_current_get(void)
rcu_read_lock();
pool = __zswap_pool_current();
- if (!pool || !zswap_pool_get(pool))
+ if (!zswap_pool_get(pool))
pool = NULL;
rcu_read_unlock();
@@ -459,7 +465,9 @@ static struct zswap_pool *zswap_pool_last_get(void)
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();
@@ -495,6 +503,17 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
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");
@@ -544,29 +563,41 @@ error:
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);
}
@@ -582,6 +613,9 @@ static void zswap_pool_destroy(struct zswap_pool *pool)
static int __must_check zswap_pool_get(struct zswap_pool *pool)
{
+ if (!pool)
+ return 0;
+
return kref_get_unless_zero(&pool->kref);
}
@@ -639,7 +673,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
}
/* 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,
@@ -670,21 +704,26 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
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
@@ -696,6 +735,17 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
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
*/
@@ -724,6 +774,10 @@ static int zswap_enabled_param_set(const char *val,
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);
}
@@ -1205,22 +1259,21 @@ static int __init init_zswap(void)
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:
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-20 19:10:41 +0000