Even if very suboptimally, for now; we copy the files, then copy them
again.
The obvious long term plan is to merge pull-local and pull together,
but truly optimizing that requires the pull code to know how to use
the OstreeRepo APIs when operating on local repositories (as
pull-local does), rather than assuming the remote is an archive-z
fetched over HTTP.
We could drop into g_main_loop_run() after the worker
thread had called g_main_loop_quit().
Fix this by following the pattern suggested by Ryan of a while loop
around our termination condition, and g_main_context_iteration().
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.
This installs a Dracut module which parses the ostree= kernel command
line argument, and if given, sets up the OS/ at /sysroot, which
systemd's switch-root then moves into. This only works if dracut is
configured to use systemd itself.
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.
This is useful for the gnome-ostree build system where each build is
one commit, but it's split up into /runtime /devel /debug etc. trees.
Ideally we wouldn't have a /debug subdirectory for "noarch"
components for example.
So add an option to not error out if the given path doesn't exist in
the commit.
When multiple threads need to uncompress an object, there was
a race condition where thread A could get EEXIST, unlink,
then thread B calls linkat(), then thread A tries to link() but
fails.
We can just loop in this case.
While this still isn't fully atomic (that depends on the bootloader),
this better ensures that the deployed kernel is booted with the
intended tree. For example, if we get ENOSPC when writing out the
kernel, we won't have swapped the symlink.
It's possible (likely even) that /tmp is on a separate filesystem; in
that case, a raw rename() is going to fail.
Saw this on the ostree.gnome.org builder.
Previously, I've observed bugs where we either:
1) Exit too early, leaving undownloaded objects
2) Hang while downloading
This rewrite hopefully fixes both.
Colin Walters