Re: [PATCH] Support INCOMPAT_64BIT on ext4

[Taylor R Campbell <campbell+netbsd-tech-kern%mumble.net@localhost>]

> Date: Wed, 23 Aug 2023 04:54:34 +0200
> From: "Vladimir 'phcoder' Serbinenko" <phcoder%gmail.com@localhost>
> 
> This patch adds support for incompat_64bit on ext4 filesystem. This feature
> is enabled by default on new filesystems on Ubuntu and probably other
> distros

Cool, thanks!  christos@ committed this.

It looks like it may have some issues, though -- a lot of ext2fs tests
are failing now.  Can you please take a look at the failures?

https://releng.netbsd.org/b5reports/i386/commits-2023.08.html#build-2023.08.26.05.47.53

   Termination reason

   FAILED: create file: No space left on device

   Standard output stream

   [   1.0000000] entropy: ready
   [   1.0200050] uid 0 on /mnt: out of inodes

FYI, if you're running a new enough kernel already, you can run the
tests yourself by doing a distribution build and then doing

# chroot /path/to/objdir/destdir.amd64
(chroot)# (cd /dev && sh MAKEDEV all)
(chroot)# mount -t ptyfs ptyfs /dev/pts
(chroot)# mount -t tmpfs tmpfs /tmp
(chroot)# cd /usr/tests/fs/vfs
(chroot)# atf-run | atf-report

You can also do build.sh release, install into a VM, and run the tests
the same way -- cd /usr/tests/fs/vfs && atf-run | atf-report.

This also broke the build of bootloaders and the newfs_ext2fs userland
tool.  I put in a stop-gap measure to restore the old definitions of
e2fs_cgload/cgsave outside the kernel, just to unbreak the build, but
it might be appropriate to make the new definitions available to
bootloaders and newfs_ext2fs too.

(I haven't looked into technical details to see whether it is
appropriate.  Probably newfs_ext2s should avoid creating file systems
this new feature for a while, but maybe have an option to do it so we
can exercise the code paths in tests.)