From: Colin Ian King <colin.king@xxxxxxxxxxxxx> Subject: drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store 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") Link: http://lkml.kernel.org/r/20191128122958.178290-1-colin.king@xxxxxxxxxxxxx Fixes: a939888ec38b ("zram: support idle/huge page writeback") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/block/zram/zram_drv.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/block/zram/zram_drv.c~zram-fix-error-return-codes-not-being-returned-in-writeback_store +++ a/drivers/block/zram/zram_drv.c @@ -629,7 +629,7 @@ static ssize_t writeback_store(struct de 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; @@ -765,7 +765,6 @@ next: if (blk_idx) free_block_bdev(zram, blk_idx); - ret = len; __free_page(page); release_init_lock: up_read(&zram->init_lock); _