Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / mm / zswap.c

diff --git a/kernel/mm/zswap.c b/kernel/mm/zswap.c
index bf14508..45476f4 100644 (file)
--- a/kernel/mm/zswap.c
+++ b/kernel/mm/zswap.c
@@ -78,7 +78,13 @@ static u64 zswap_duplicate_entry;
 
 /* Enable/disable zswap (disabled by default) */
 static bool zswap_enabled;
-module_param_named(enabled, zswap_enabled, bool, 0644);
+static int zswap_enabled_param_set(const char *,
+                                  const struct kernel_param *);
+static struct kernel_param_ops zswap_enabled_param_ops = {
+       .set =          zswap_enabled_param_set,
+       .get =          param_get_bool,
+};
+module_param_cb(enabled, &zswap_enabled_param_ops, &zswap_enabled, 0644);
 
 /* Crypto compressor to use */
 #define ZSWAP_COMPRESSOR_DEFAULT "lzo"
@@ -170,10 +176,15 @@ static struct zswap_tree *zswap_trees[MAX_SWAPFILES];
 static LIST_HEAD(zswap_pools);
 /* protects zswap_pools list modification */
 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;
 
+/* fatal error during init */
+static bool zswap_init_failed;
+
 /*********************************
 * helpers and fwd declarations
 **********************************/
@@ -565,6 +576,7 @@ static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
 static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
 {
        struct zswap_pool *pool;
+       char name[38]; /* 'zswap' + 32 char (max) num + \0 */
        gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
 
        pool = kzalloc(sizeof(*pool), GFP_KERNEL);
@@ -573,7 +585,10 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
                return NULL;
        }
 
-       pool->zpool = zpool_create_pool(type, "zswap", gfp, &zswap_zpool_ops);
+       /* unique name for each pool specifically required by zsmalloc */
+       snprintf(name, 38, "zswap%x", atomic_inc_return(&zswap_pools_count));
+
+       pool->zpool = zpool_create_pool(type, name, gfp, &zswap_zpool_ops);
        if (!pool->zpool) {
                pr_err("%s zpool not available\n", type);
                goto error;
@@ -696,6 +711,11 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
        char *s = strstrip((char *)val);
        int ret;
 
+       if (zswap_init_failed) {
+               pr_err("can't set param, initialization failed\n");
+               return -ENODEV;
+       }
+
        /* no change required */
        if (!strcmp(s, *(char **)kp->arg))
                return 0;
@@ -775,6 +795,17 @@ static int zswap_zpool_param_set(const char *val,
        return __zswap_param_set(val, kp, NULL, zswap_compressor);
 }
 
+static int zswap_enabled_param_set(const char *val,
+                                  const struct kernel_param *kp)
+{
+       if (zswap_init_failed) {
+               pr_err("can't enable, initialization failed\n");
+               return -ENODEV;
+       }
+
+       return param_set_bool(val, kp);
+}
+
 /*********************************
 * writeback code
 **********************************/
@@ -1261,6 +1292,9 @@ pool_fail:
 dstmem_fail:
        zswap_entry_cache_destroy();
 cache_fail:
+       /* if built-in, we aren't unloaded on failure; don't allow use */
+       zswap_init_failed = true;
+       zswap_enabled = false;
        return -ENOMEM;
 }
 /* must be late so crypto has time to come up */