diff options
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 3428f647d0a7..1a1159a70fb4 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -566,6 +566,16 @@ static ssize_t writeback_limit_store(struct device *dev, if (kstrtoull(buf, 10, &val)) return ret; + /* + * When the page size is greater than 4KB, if bd_wb_limit is set to + * a value that is not page - size aligned, it will cause value + * wrapping. For example, when the page size is set to 16KB and + * bd_wb_limit is set to 3, a single write - back operation will + * cause bd_wb_limit to become -1. Even more terrifying is that + * bd_wb_limit is an unsigned number. + */ + val = rounddown(val, PAGE_SIZE / 4096); + down_write(&zram->init_lock); zram->bd_wb_limit = val; up_write(&zram->init_lock); |