Adjust queue limits for stacked drivers
int bdev_stack_limits(struct queue_limits * t, struct block_device * bdev, sector_t start);
t
the stacking driver limits (top device)
bdev
the component block_device (bottom)
start
first data sector within component device
Merges queue limits for a top device and a block_device. Returns 0 if alignment didn't change. Returns -1 if adding the bottom device caused misalignment.