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Commit bae21db8 authored by Dan Streetman's avatar Dan Streetman Committed by Linus Torvalds
Browse files

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: default avatarDan 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ae3d89a7

mm/zswap.c

+37 −12
Original line number Diff line number Diff line
@@ -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 *,
@@ -501,6 +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");
@@ -550,28 +563,40 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) 


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);

}