[PATCH] zram: fix error return codes not being returned in writeback_store

From: Colin King
Date: Thu Nov 28 2019 - 07:30:03 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Currently when an error code -EIO or -ENOSPC in the for-loop of
writeback_store the error code is being overwritten by a ret = len
assignment at the end of the function and the error codes are being
lost. Fix this by assigning ret = len at the start of the function
and remove the assignment from the end, hence allowing ret to be
preserved when error codes are assigned to it.

Addresses-Coverity: ("Unused value")
Fixes: a939888ec38b ("zram: support idle/huge page writeback")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 4285e75e52c3..1bf4a908a0bd 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -626,7 +626,7 @@ static ssize_t writeback_store(struct device *dev,
struct bio bio;
struct bio_vec bio_vec;
struct page *page;
- ssize_t ret;
+ ssize_t ret = len;
int mode;
unsigned long blk_idx = 0;

@@ -762,7 +762,6 @@ static ssize_t writeback_store(struct device *dev,

if (blk_idx)
free_block_bdev(zram, blk_idx);
- ret = len;
__free_page(page);
release_init_lock:
up_read(&zram->init_lock);
--
2.24.0