Extracting the code for parse_ostree_cmdline() and running it on some
test input (on RHEL6.4 glibc), I can reproduce the odd behavior from
getline() where it apparently returns the size of the default malloc
buffer in the size output, and some non-zero value.
This behavior would be OK except that it breaks the logic for
stripping off the trailing newline, which in turn breaks booting
because we return "ostree=foo\n".
This has worked so far in gnome-ostree because syslinux apparently
injects initrd=/path/to/initrd as a final kernel argment.
Anyways, we don't handle NUL characters here in /proc/cmdline, so
let's just call strlen () to be safe.
https://bugzilla.gnome.org/show_bug.cgi?id=707192
While the systemd integration effectively requires /sysroot, it will
help people trying to use OSTree with other initramfs systems
(e.g. initramfs-tools) if we don't hardcode that requirement in this
tool.
See https://wiki.gnome.org/OSTree/DeploymentModel2
This is a major rework of the on-disk filesystem layout, and the boot
process. OSTree now explicitly supports upgrading kernels, and these
upgrades are also atomic.
The core concept of the new model is the "deployment list", which is
an ordered list of bootable operating system trees. The deployment
list is reflected in the bootloader configuration; which has a kernel
argument that tells the initramfs (dracut) which operating system root
to use.
Invidiual notable changes that come along with this:
1) Operating systems should now come with their etc in usr/etc; OSTree
will perform a 3-way merge at deployment time, and place etc in
the actual root. This avoids the need for a bind mount, and is
just a lot cleaner.
2) OSTree no longer bind mounts /root, /home, and /tmp. It is expected
that the the OS/ has these as symbolic links into /var.
At the moment, OSTree only supports managing syslinux; other
bootloader backends will follow.
Linux creates a copy of the soure mount flags when creating a bind
mount; if the source is read-only, then the bind mount is.
The problem is that systemd will remount the rootfs read/write, but
each mount (/home, /var etc.) will still be read-only. We need to
remount every bind mount except for /usr to read-write too.
This only "worked" with the old ostree-switch-root because it
effectively force mounted the rootfs read-write always, ignoring the
"ro" flag.
Rather than attempting to hack up the "switch-root" functionality of
systemd, this binary allows us to simply prepare the root before we
switch into it.
Colin Walters