Re: [PATCH] fix floppy for PAGE_SIZE != 4KB

[Jens Axboe <axboe@kernel.dk>]

On 11/17/25 2:56 AM, Ren? Rebe wrote:
> Hi,
> 
>>> 64k is 4% of a floppy disk! But I hear you, works for you.
>>
>> Again, still only 8k or 16k for most of such remaining workstation
>> floppy users.
>>
>>>> But if someone wants to refactor this code some more, ... I'm happy to
>>>> test it, too ;-)
>>>
>>> I don't think refactoring would be required here, it's probably just
>>> capping that probe read to something constant irrespective of hardware
>>> page sizes.
>>
>> Well, the floppy.c __floppy_read_block_0 does:
>>        bio_init(&bio, bdev, &bio_vec, 1, REQ_OP_READ);
>>        __bio_add_page(&bio, page, block_size(bdev), 0);
>>
>> Is there an easy way to limit that to less than a page without
>> refactoring it too much? Otherwise we could just apply this hotfix for
>> now.
> 
> 
> Any chance we can get my initial one liner constant PAGE_SIZE fix
> for this over a decade old bug in? I currently don?t have a budget
> to refactor the floppy driver probing for efficiency on bigger PAGE_SIZE
> configs I?m not even having a floppy controller on.

Yep we can do that. It'd be great if we could augment the change with
what commit broke it, so it can get backported to stable kernels as
well. Was it:

commit fe4ec12e1865a2114056b799e4869bf4c30e47df
Author: Christoph Hellwig <hch@lst.de>
Date:   Fri Jun 26 10:01:52 2020 +0200

    floppy: use block_size

?

-- 
Jens Axboe