On Fri, Aug 07, 2020 at 12:02:30PM -0700, Bart Van Assche wrote:
On 2020-08-07 10:10, Keith Busch wrote:
On Fri, Aug 07, 2020 at 07:18:49AM -0700, Bart Van Assche wrote:
Hi Keith,
How about replacing your patch with the (untested) patch below?
I believe that should be fine, but I broke the kernel last time I did something like that. I still think it was from incorrect queue_limits, but Linus disagreed.
Hi Keith,
Thanks for the interesting link. Regarding Linus' comments about bio splitting: if the last return statement in get_max_io_size() is reached then it is guaranteed that sectors < pbs (physical block size). So I think that Linus' comment applies to the previous return statement instead of to the last ("return max_sectors - start_offset;"). However, I think it is already guaranteed that that value is a multiple of the logical block size because start_offset is a multiple of the logical block size and because of the following statement: "max_sectors &= ~(pbs - 1);".
This breaks if limits.max_sectors is not a multiple of the queue's logical block size and the physical block size is larger than max_sectors.