[PATCH] olpc.fth - grow the root filesystem partition on boot

[Peter Robinson]

On Wed, Mar 14, 2012 at 11:48 PM, James Cameron <quozl at laptop.org> wrote:
> On Wed, Mar 14, 2012 at 11:33:32PM +0000, Peter Robinson wrote:
>> On Wed, Mar 14, 2012 at 11:29 PM, James Cameron <quozl at laptop.org> wrote:
>> > On Wed, Mar 14, 2012 at 07:02:51PM -0400, John Watlington wrote:
>> >>
>> >> On Mar 14, 2012, at 6:04 PM, James Cameron wrote:
>> >>
>> >> > On Wed, Mar 14, 2012 at 08:37:23AM -0600, Daniel Drake wrote:
>> >> >> On Wed, Mar 14, 2012 at 7:06 AM, Richard Smith <richard at laptop.org> wrote:
>> >> >>> On Wed, Mar 14, 2012 at 1:35 AM, James Cameron <quozl at laptop.org> wrote:
>> >> >>>> Grows the second partition so that it takes up all remaining space on
>> >> >>>> the eMMC or microSD card. ?Fix for #11690. ?Part of #10040.
>> >> >>>>
>> >> >>>> Costs 120ms. ?(Use of a flag file costs 130ms).
>> >> >>>>
>> >> >>>
>> >> >>> I don't think its necessary to do this check every boot. I propose you
>> >> >>> move it to after fs-update has installed an image.
>> >> >>
>> >> >> Also, olpc.fth isn't executed in the secure boot path, so it does need
>> >> >> to be put somewhere else. I like Richard's suggestion.
>> >> >
>> >> > This would break fs-verify, and is therefore unacceptable.
>> >>
>> >> Is this really a concern ? ? It doesn't break fs-verify if one is using the correct
>> >> image for the storage device in question. ? Or are we tweaking the filesystem
>> >> to get the extra few MB with some cards ?
>> >
>> > With #11690 and #10040 fixed, we would only need to create one image for
>> > the smallest storage device shipped. ?Every image would then be the
>> > correct image.
>> >
>> > Yes, this method can be used to "free up" the unused space between the
>> > size of the smallest image and the size of the smallest storage device
>> > shipped, but that is a side-effect.
>> >
>> > fs-verify is used after fs-update in factory to ensure that the
>> > fs-update was successful.
>>
>> Stupid question but can't you just do fs-update -> fs-verify to verify
>> the image installed is imaged over correctly -> fs-expand to expand it
>> to a full size once we know the image is good?
>
> Yes, but that would be an extra step for deployment.
>
> I would prefer to solve this by having Linux expand the partition, but
> I'm told that can't work because Linux doesn't see the new size until
> next boot.  Do you know a way to avoid a reboot?

There's the partprobe utility which is part of the parted package, we
ship it. It will re-read the partition table without a reboot.

Peter