Re: [LTP] [PATCH] fs_fill: Fix test when running on a 256 CPU+ machine

Andrei Gherzan
2023-03-09T16:25:05Z

On 23/03/08 05:55PM, Petr Vorel wrote:
> Hi Andrei,
>
> > > > The fs_fill test runs a fill test on all the supported filesystems. One
> > > > of them being vfat. This filesystem is configured dynamically or through
> > > > flags/arguments for its file allocation table type (12/16/32).
>
> > > > The size of the test device (which is a loop-mounted fs) is 300MB. When not
> > > > instructed, mkfs will "automatically select between 12, 16 and 32 bit,
> > > > whatever fits better for the filesystem size"[1]. In the case of a 300Mb that
> > > > would end up as FAT16.
> > > Interesting. BTW we plan to change 300 MB to minimal filesystem which would fit
> > > to all existing tests (255 MB was for Btrfs, 300 MB was for XFS, but there might
> > > be minimal systems which can use vfat, ext4, ... with smaller resources, e.g.
> > > 16 MB for filesystem). Therefore I wonder what is minimal reasonable required
> > > size for vfat. i.e. what MB is required for FAT32? (I guess we don't want to
> > > check FAT12 or FAT16).
>
> > The minimum/maximum values depend on the sector size. I'm not sure about
> > F12 but for the other ones I think it was 32MB for 512b sectors.
>
> Thanks a lot for info. BTW I'm not convinced any more that using as smallest
> loop device size as possible is a good idea.

I agree. The moment we start getting into the limits of fs sizes, we
will end up in issues like this.

--
Andrei Gherzan