Re: [PATCH 1/2] bcache: avoid nr_stripes overflow in bcache_device_init()

On 2020/7/13 01:47, Coly Li wrote:

For some block devices which large capacity (e.g. 8TB) but small io_opt size (e.g. 8 sectors), in bcache_device_init() the stripes number calcu- lated by, DIV_ROUND_UP_ULL(sectors, d->stripe_size); might be overflow to the unsigned int bcache_device->nr_stripes.

This patch uses an unsigned long variable to store DIV_ROUND_UP_ULL() and after the value is checked to be available in unsigned int range, sets it to bache_device->nr_stripes. Then the overflow is avoided.

Hi Ken,

Could you please to try whether these two patches may avoid the kernel panic ? I will post the overwhelm stripe_size patch later.

Thanks.

Coly Li