[PATCHv3 11/19] zram: extend comp_algorithm attr write handling

[Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>]

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 | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 6c36cd349431..bd8433363cbe 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1028,9 +1028,33 @@ 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;
 	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 (!alg)
+		return -EINVAL;
+
+	ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, alg);
 	return ret ? ret : len;
 }
 
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog