[PATCH v6 15/23] zram: extend comp_algorithm attr write handling

[Sergey Senozhatsky]

Previously comp_algorithm device attr would accept only
algorithm name param, however in order to enabled comp
configuration we need to extend comp_algorithm_store()
with param=value support.

Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
 drivers/block/zram/zram_drv.c | 54 +++++++++++++++++++++++++++++++++--
 1 file changed, 52 insertions(+), 2 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 84757f0c8166..a2c23ca033b5 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -998,6 +998,12 @@ static int __comp_algorithm_store(struct zram *zram, u32 prio, const char *buf)
 	return 0;
 }
 
+static int comp_params_store(struct zram *zram, u32 prio, s32 level)
+{
+	zram->params[prio].level = level;
+	return 0;
+}
+
 static ssize_t comp_algorithm_show(struct device *dev,
 				   struct device_attribute *attr,
 				   char *buf)
@@ -1013,9 +1019,43 @@ static ssize_t comp_algorithm_store(struct device *dev,
 				    size_t len)
 {
 	struct zram *zram = dev_to_zram(dev);
+	char *args, *param, *val;
+	char *alg = NULL;
+	s32 level = ZCOMP_PARAM_NO_LEVEL;
 	int ret;
 
-	ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, buf);
+	args = skip_spaces(buf);
+	while (*args) {
+		args = next_arg(args, &param, &val);
+
+		/*
+		 * We need to support 'param' without value, which is an
+		 * old format for this attr (algorithm name only).
+		 */
+		if (!val || !*val) {
+			alg = param;
+			continue;
+		}
+
+		if (!strcmp(param, "algo")) {
+			alg = val;
+			continue;
+		}
+
+		if (!strcmp(param, "level")) {
+			ret = kstrtoint(val, 10, &level);
+			if (ret)
+				return ret;
+			continue;
+		}
+	}
+
+	if (!alg)
+		return -EINVAL;
+
+	ret = comp_params_store(zram, ZRAM_PRIMARY_COMP, level);
+	if (!ret)
+		ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, alg);
 	return ret ? ret : len;
 }
 
@@ -1048,6 +1088,7 @@ static ssize_t recomp_algorithm_store(struct device *dev,
 	int prio = ZRAM_SECONDARY_COMP;
 	char *args, *param, *val;
 	char *alg = NULL;
+	s32 level = ZCOMP_PARAM_NO_LEVEL;
 	int ret;
 
 	args = skip_spaces(buf);
@@ -1068,6 +1109,13 @@ static ssize_t recomp_algorithm_store(struct device *dev,
 				return ret;
 			continue;
 		}
+
+		if (!strcmp(param, "level")) {
+			ret = kstrtoint(val, 10, &level);
+			if (ret)
+				return ret;
+			continue;
+		}
 	}
 
 	if (!alg)
@@ -1076,7 +1124,9 @@ static ssize_t recomp_algorithm_store(struct device *dev,
 	if (prio < ZRAM_SECONDARY_COMP || prio >= ZRAM_MAX_COMPS)
 		return -EINVAL;
 
-	ret = __comp_algorithm_store(zram, prio, alg);
+	ret = comp_params_store(zram, prio, level);
+	if (!ret)
+		ret = __comp_algorithm_store(zram, prio, alg);
 	return ret ? ret : len;
 }
 #endif
-- 
2.45.2.993.g49e7a77208-goog