From: "Theodore Ts'o" <tytso@mit.edu>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Andreas Dilger <adilger@dilger.ca>,
linux-ext4 <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH v2] mke2fs: warn about missing y2038 support when formatting fresh ext4 fs
Date: Fri, 13 Aug 2021 15:32:48 -0400 [thread overview]
Message-ID: <YRbI4E3b42X3otJv@mit.edu> (raw)
In-Reply-To: <20210813181436.GZ3601466@magnolia>
On Fri, Aug 13, 2021 at 11:14:36AM -0700, Darrick J. Wong wrote:
> > There were only two cases where we created file systems with 128 byte
> > inodes --- "small" and "floppy" sized file systems, and for the GNU
> > Hurd, which only supports the original 128 byte inode. What will GNU
> > Hurd do in 16.5 years? ¯\_(ツ)_/¯
>
> Perhaps in that time someone can donate a disused Opteron 140 system?
> Assuming the motherboard capacitors haven't since lost their mojo.
Apparently GNU Hurd uses a unsigned 32-bit int for time_t, so they
have a 2106 problem. They "have no plans for a 64-bit userspace, but
they have plans for a 64-bit kernel that can run 32-bit user space".
Comments from the the GNU Hurd folks on an IRC chat from 2013:
<braunr> which overflows in 2106
<braunr> and we already include funny comments that predict our successors,
if any, will probably fail to deal with the problem until short before
the overflow :>
<azeem> luckily, no nuclear reactors are running the Hurd sofar
https://www.gnu.org/software/hurd/open_issues/versioning.html
> > + /*
> > + * Warn the user that filesystems with 128-byte inodes will
> > + * not work properly beyond 2038. This can be suppressed via
> > + * a boolean in the mke2fs.conf file, and we will disable this
> > + * warning for ext2, ext3, and hurd file systems.
>
> Um... the conffile changes only disable the warning for Hurd?
Oops, good catch, I'll fix up the comment.
> > +This boolean relation specifies wheather mke2fs will issue a warning
> > +when creating a file system with 128 byte inodes (and so therefore will
> > +not support dates after January 19th, 2038. The default value is true,
>
> Nit: need a closing parentheses after '2038' or no opening paren.
Thanks, fixed.
> > +except for file systems created for the GNU Hurd, which does not support
> > +inodes larger than 128 bytes.
>
> I wonder if this statementt about Hurd this belongs in the conffile as a
> comment in the hurd section?
We currently don't have a Hurd section. We probably could document
more about the magic that mke2fs does when you specify "-o hurd",
which probably should go in the mke2fs man page but I can't quite
bring myself to care. Maybe some GNU Hurd folks can get interested to
do this? :-)
- Ted
next prev parent reply other threads:[~2021-08-13 19:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-12 23:22 [PATCH v2] mke2fs: warn about missing y2038 support when formatting fresh ext4 fs Darrick J. Wong
2021-08-13 17:52 ` Theodore Ts'o
2021-08-13 18:14 ` Darrick J. Wong
2021-08-13 19:32 ` Theodore Ts'o [this message]
2021-08-13 19:34 ` [PATCH -v4] " Theodore Ts'o
2021-08-13 19:35 ` Theodore Ts'o
2021-08-13 19:35 ` [PATCH -v5] " Theodore Ts'o
2021-08-13 20:31 ` Darrick J. Wong
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