diff options
| -rw-r--r-- | mm/zswap.c | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index cabf09e0128b..77cb847938e1 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -185,6 +185,9 @@ 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 +427,8 @@ 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 +447,7 @@ 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 +463,9 @@ 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(); @@ -582,6 +588,9 @@ 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 +648,7 @@ 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, @@ -685,6 +694,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, 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 @@ -692,6 +702,15 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, */ list_add_tail_rcu(&pool->list, &zswap_pools); put_pool = pool; + } else if (!zswap_has_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); } spin_unlock(&zswap_pools_lock); @@ -724,6 +743,10 @@ 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 +1228,21 @@ 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: |