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author | Colin Walters <walters@verbum.org> | 2017-05-11 14:54:12 -0400 |
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committer | Atomic Bot <atomic-devel@projectatomic.io> | 2017-05-16 16:13:05 +0000 |
commit | 30705889cb867c18cdb7fed8e55dc46477c069fa (patch) | |
tree | b6247fa4e4d51ad7a44bfef90381f3aad47c9d52 /src/switchroot/ostree-system-generator.c | |
parent | d815ba2a81ad14d9d4edc31dcd282dcc2a3a8fb9 (diff) | |
download | ostree-30705889cb867c18cdb7fed8e55dc46477c069fa.tar.gz |
Switch to using a systemd generator for /var
If one wants to set up a mount for `/var` in `/etc/fstab`, it
won't be mounted since `ostree-prepare-root` set up a bind mount for
`/var` to `/sysroot/ostree/$stateroot/var`, and systemd will take
the already extant mount over what's in `/etc/fstab`.
There are a few options to fix this, but what I settled on is parsing
`/etc/fstab` in a generator (exactly like `systemd-fstab-generator` does),
except here we look for an explicit mount for `/var`, and if one *isn't* found,
synthesize the default ostree mount to the stateroot. Another nice property is
that if an admin creates a `var.mount` unit in `/etc` for example, that will
also override our mount.
Note that today ostree doesn't hard depend on systemd, so this behavior only
kicks in if we're built with systemd *and* libmount support (for parsing
`/etc/fstab`). I didn't really test that case though.
Initially I started writing this as a "pure libc" program, but at one point
decided to use `libostree.so` to find the booted deployment. That didn't work
out because `/boot` wasn't necessarily mounted and hence we couldn't find the
bootloader config. A leftover artifact from this is that the generator code
calls into libostree via the "cmd private" infrastructure. But it's an easy way
to share code, and doesn't hurt.
Closes: #859
Approved by: jlebon
Diffstat (limited to 'src/switchroot/ostree-system-generator.c')
-rw-r--r-- | src/switchroot/ostree-system-generator.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/src/switchroot/ostree-system-generator.c b/src/switchroot/ostree-system-generator.c new file mode 100644 index 00000000..e7205b5a --- /dev/null +++ b/src/switchroot/ostree-system-generator.c @@ -0,0 +1,67 @@ +/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- + * + * Copyright (C) 2017 Colin Walters <walters@verbum.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#include "config.h" + +#include <err.h> +#include <unistd.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <stdlib.h> + +#include "ostree-cmdprivate.h" +#include "ostree-mount-util.h" + +static const char *arg_dest = "/tmp"; +static const char *arg_dest_late = "/tmp"; + +/* This program is a simple stub that calls the implementation that + * lives inside libostree. + */ +int +main(int argc, char *argv[]) +{ + /* Important: if this isn't an ostree-booted system, do nothing; people could + * have the package installed as a dependency for flatpak or whatever. + */ + { struct stat stbuf; + if (fstatat (AT_FDCWD, "/run/ostree-booted", &stbuf, 0) < 0) + exit (EXIT_SUCCESS); + } + + if (argc > 1 && argc != 4) + errx (EXIT_FAILURE, "This program takes three or no arguments"); + + if (argc > 1) + arg_dest = argv[1]; + if (argc > 3) + arg_dest_late = argv[3]; + + char *ostree_cmdline = read_proc_cmdline_ostree (); + if (!ostree_cmdline) + errx (EXIT_FAILURE, "Failed to find ostree= kernel argument"); + + { g_autoptr(GError) local_error = NULL; + if (!ostree_cmd__private__()->ostree_system_generator (ostree_cmdline, arg_dest, NULL, arg_dest_late, &local_error)) + errx (EXIT_FAILURE, "%s", local_error->message); + } + + exit (EXIT_SUCCESS); +} |