On 7/12/20 1:49 PM, Coly Li wrote:
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
I will. But, from inspection: On a 32-bit system, "unsigned long" will
still be 32 bits, but sector_t (u64) will still be 64 bits, so that
assignment will still discard high bits before validation in that
environment. I suggest "unsigned long long" or another specifically
64-bit type.
Also, the VDO driver I work on doesn't support 32-bit platforms
currently, so my own testing will be limited to 64-bit platforms.
Ken
