[PATCH 3/4] zram: reject unrecognized type= values in recompress_store()

[Andrew Stellman]

recompress_store() parses the type= parameter with three independent if
statements checking for "idle", "huge", and "huge_idle". An
unrecognized value silently falls through with mode left at 0, causing
the recompression pass to run with no slot filter — processing all
slots instead of the intended subset.

Convert the if chain to if/else if/else and return -EINVAL for
unrecognized values, consistent with the function's other parameter
validation.

Signed-off-by: Andrew Stellman <astellman@xxxxxxxxxxxxxxxxxxx>
---
 drivers/block/zram/zram_drv.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 8ea2a12..67dea80 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2555,10 +2555,12 @@ static ssize_t recompress_store(struct device *dev,
 		if (!strcmp(param, "type")) {
 			if (!strcmp(val, "idle"))
 				mode = RECOMPRESS_IDLE;
-			if (!strcmp(val, "huge"))
+			else if (!strcmp(val, "huge"))
 				mode = RECOMPRESS_HUGE;
-			if (!strcmp(val, "huge_idle"))
+			else if (!strcmp(val, "huge_idle"))
 				mode = RECOMPRESS_IDLE | RECOMPRESS_HUGE;
+			else
+				return -EINVAL;
 			continue;
 		}
 
-- 
2.34.1