Re: [PATCH] loop: Increase bsize variable from unsigned short to unsigned int

From: Li Wang
Date: Tue Aug 27 2024 - 03:36:57 EST


On Tue, Aug 27, 2024 at 3:20 PM John Garry <john.g.garry@xxxxxxxxxx> wrote:
>
> On 27/08/2024 04:22, Li Wang wrote:
>
> +linux-block, Jens
>
> > This change allows the loopback driver to handle larger block sizes
>
> larger than what? PAGE_SIZE?

Yes, system should return EINVAL when the tested bsize is larger than PAGE_SIZE.
But due to the loop_reconfigure_limits() cast it to 'unsined short' that
never gets an expected error when testing invalid logical block size.

That's why LTP/ioctl_loop06 failed on a system with 64k (ppc64le) pagesize
(since kernel-v6.11-rc1 with patches):

9423c653fe6110 ("loop: Don't bother validating blocksize")
fe3d508ba95bc6 ("block: Validate logical block size in blk_validate_limits()")



--
Regards,
Li Wang