linux-ext4 - Re: Why is 64bit option always on by default now?

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Message-ID: <20170105071343.GA7166@quack2.suse.cz>
Date:   Thu, 5 Jan 2017 08:13:43 +0100
From:   Jan Kara <jack@...e.cz>
To:     Dan Arena <ddan39@...il.com>
Cc:     Jan Kara <jack@...e.cz>, Theodore Ts'o <tytso@....edu>,
        linux-ext4@...r.kernel.org
Subject: Re: Why is 64bit option always on by default now?

On Wed 04-01-17 11:51:19, Dan Arena wrote:
> Yes, u-boot is what our boards come with too. It looks like 64bit is actually
> implemented in u-boot now, but only as of a few months ago... see http://
> lists.denx.de/pipermail/u-boot/2016-September/266857.html

Yep, probably a result of that guy who took care of the openSUSE report.

> The board manufacturer told me they are looking into adding it... (they just
> have to update u-boot i guess?)

AFAIK that should be enough, yes.

								Honza

> 
> On Jan 4, 2017 11:18 AM, "Jan Kara" <jack@...e.cz> wrote:
> 
>     On Thu 22-12-16 21:45:37, Ted Tso wrote:
>     > 64-bit support has been around for 7 years (since e2fsprogs 1.41).
>     > And yes, e2fsprogs 1.43 now has the ability to convert a file system
>     > from 32-bit to 64-bit, but this is an inherently dangerous thing to
>     > do, since it requires rewriting the inode table.  If you ever crash or
>     > power fail during the conversion, *boom*, you can lose all or most of
>     > your data.  So the conversion can be used as a short cut where you
>     > back up the whole file system, and then try to convert to 64-bit, and
>     > if it succeeds, then you don't have to do the restore step.  If it
>     > crashes and you lose everything, then you can reformat the file system
>     > and restore from backups.  :-)
>     >
>     > In general, I assume that embedded developers are more sophisticated
>     > than users (who will use the mke2fs in the installer to install thier
>     > root file system, which will be a matched set with the bootloader).  I
>     > also can't be responsible for crappy, obsolete bootloader on embedded
>     > devices, some of which have device drivers only available in ancient
>     > BSP kernels using 3.10, etc.
> 
>     Just to add some more data, we have actually got similar reports few months
>     ago for openSUSE once we shipped updated e2fsprogs. And the bootloader they
>     used (u-boot) does not support 64-bit feature at all. My answer has been
>     similar to yours - either update the bootloader or change mke2fs.conf in
>     your setup. There's one guy working on implementing 64-bit support in
>     u-boot BTW.
> 
>                                                                     Honza
>     --
>     Jan Kara <jack@...e.com>
>     SUSE Labs, CR
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR
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