mm/zswap.c: change params from hidden to ro

The "compressor" and "enabled" params are currently hidden, this changes
them to read-only, so userspace can tell if zswap is enabled or not and
see what compressor is in use.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Vladimir Murzin <murzin.v@gmail.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zswap.c

@@ -77,12 +77,12 @@ static u64 zswap_duplicate_entry;
 **********************************/
 /* Enable/disable zswap (disabled by default, fixed at boot for now) */
 static bool zswap_enabled __read_mostly;
-module_param_named(enabled, zswap_enabled, bool, 0);
+module_param_named(enabled, zswap_enabled, bool, 0444);
 
 /* Compressor to be used by zswap (fixed at boot for now) */
 #define ZSWAP_COMPRESSOR_DEFAULT "lzo"
 static char *zswap_compressor = ZSWAP_COMPRESSOR_DEFAULT;
-module_param_named(compressor, zswap_compressor, charp, 0);
+module_param_named(compressor, zswap_compressor, charp, 0444);
 
 /* The maximum percentage of memory that the compressed pool can occupy */
 static unsigned int zswap_max_pool_percent = 20;