zswap: clear compressor or zpool param if invalid at init
If either the compressor and/or zpool param are invalid at boot, and
their default value is also invalid, set the param to the empty string
to indicate there is no compressor and/or zpool configured. This allows
users to check the sysfs interface to see which param needs changing.
Link: http://lkml.kernel.org/r/20170124200259.16191-4-ddstreet@ieee.org
Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/zswap.c b/mm/zswap.c
index 77cb847..9e8565d 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -76,6 +76,8 @@
* tunables
**********************************/
+#define ZSWAP_PARAM_UNSET ""
+
/* Enable/disable zswap (disabled by default) */
static bool zswap_enabled;
static int zswap_enabled_param_set(const char *,
@@ -501,6 +503,17 @@
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");
@@ -550,28 +563,40 @@
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);
}