[systemd-devel] [RFC] [PATCHv2 3/3] resume-generator: add a generator for instantiating the resume unit.
Thomas H.P. Andersen
phomes at gmail.com
Sun Aug 24 04:41:28 PDT 2014
On Sat, Aug 23, 2014 at 8:59 PM, Ivan Shapovalov <intelfx100 at gmail.com> wrote:
> resume-generator understands resume= kernel command line parameter and
> instantiates the systemd-resume at .service accordingly if it is passed.
>
> This enables resume from hibernation using device specified on the kernel
> command line, where the device path may point to an arbitrary udev-created
> symlink, not only "/dev/sdXY" which is understood by the in-kernel
> implementation.
> ---
> Makefile-man.am | 2 +
> man/kernel-command-line.xml | 13 ++++-
> man/systemd-resume-generator.xml | 91 ++++++++++++++++++++++++++++++++
> src/resume-generator/Makefile | 1 +
> src/resume-generator/resume-generator.c | 93 +++++++++++++++++++++++++++++++++
> 5 files changed, 199 insertions(+), 1 deletion(-)
> create mode 100644 man/systemd-resume-generator.xml
> create mode 120000 src/resume-generator/Makefile
> create mode 100644 src/resume-generator/resume-generator.c
>
> diff --git a/Makefile-man.am b/Makefile-man.am
> index be19905..00daae2 100644
> --- a/Makefile-man.am
> +++ b/Makefile-man.am
> @@ -76,6 +76,7 @@ MANPAGES += \
> man/systemd-nspawn.1 \
> man/systemd-path.1 \
> man/systemd-remount-fs.service.8 \
> + man/systemd-resume-generator.8 \
> man/systemd-resume at .service.8 \
> man/systemd-run.1 \
> man/systemd-shutdownd.service.8 \
> @@ -1632,6 +1633,7 @@ EXTRA_DIST += \
> man/systemd-readahead-replay.service.xml \
> man/systemd-remount-fs.service.xml \
> man/systemd-resolved.service.xml \
> + man/systemd-resume-generator.xml \
> man/systemd-resume at .service.xml \
> man/systemd-rfkill at .service.xml \
> man/systemd-run.xml \
> diff --git a/man/kernel-command-line.xml b/man/kernel-command-line.xml
> index f244bfc..4bc6cee 100644
> --- a/man/kernel-command-line.xml
> +++ b/man/kernel-command-line.xml
> @@ -351,6 +351,16 @@
> </listitem>
> </varlistentry>
>
> + <varlistentry>
> + <term><varname>resume=</varname></term>
> +
> + <listitem>
> + <para>Enables resume from hibernation
> + using the specified device. For
> + details, see
> + <citerefentry><refentrytitle>systemd-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
> + </listitem>
> + </varlistentry>
> </variablelist>
>
> </refsect1>
> @@ -373,7 +383,8 @@
> <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
> <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
> <citerefentry><refentrytitle>systemd-backlight at .service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
> - <citerefentry><refentrytitle>systemd-rfkill at .service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
> + <citerefentry><refentrytitle>systemd-rfkill at .service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
> + <citerefentry><refentrytitle>systemd-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
> </para>
> </refsect1>
>
> diff --git a/man/systemd-resume-generator.xml b/man/systemd-resume-generator.xml
> new file mode 100644
> index 0000000..7962534
> --- /dev/null
> +++ b/man/systemd-resume-generator.xml
> @@ -0,0 +1,91 @@
> +<?xml version="1.0"?>
> +<!--*-nxml-*-->
> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
> +<!--
> + This file is part of systemd.
> +
> + Copyright 2014 Ivan Shapovalov
> +
> + systemd 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 2.1 of the License, or
> + (at your option) any later version.
> +
> + systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
> +-->
> +<refentry id="systemd-resume-generator">
> +
> + <refentryinfo>
> + <title>systemd-resume-generator</title>
> + <productname>systemd</productname>
> +
> + <authorgroup>
> + <author>
> + <contrib>Developer</contrib>
> + <firstname>Ivan</firstname>
> + <surname>Shapovalov</surname>
> + <email>intelfx100 at gmail.com</email>
> + </author>
> + </authorgroup>
> + </refentryinfo>
> +
> + <refmeta>
> + <refentrytitle>systemd-resume-generator</refentrytitle>
> + <manvolnum>8</manvolnum>
> + </refmeta>
> +
> + <refnamediv>
> + <refname>systemd-resume-generator</refname>
> + <refpurpose>Unit generator for resume= kernel parameter</refpurpose>
> + </refnamediv>
> +
> + <refsynopsisdiv>
> + <para><filename>/usr/lib/systemd/system-generators/systemd-resume-generator</filename></para>
> + </refsynopsisdiv>
> +
> + <refsect1>
> + <title>Description</title>
> +
> + <para><filename>systemd-resume-generator</filename> is
> + a generator that instantiates
> + <citerefentry><refentrytitle>systemd-resume at .service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
> + unit according to the value of <option>resume=</option>
> + parameter specified on the kernel command line.</para>
> + </refsect1>
> +
> + <refsect1>
> + <title>Kernel Command Line</title>
> +
> + <para><filename>systemd-resume-generator</filename> understands
> + the following kernel command line parameters:</para>
> +
> + <variablelist class='kernel-commandline-options'>
> +
> + <varlistentry>
> + <term><varname>resume=</varname></term>
> +
> + <listitem><para>Takes a path to the resume
> + device. May point to any udev-created symlink,
> + including persistent block device pathes like
> + <filename>/dev/disk/by-label/foo</filename>.</para></listitem>
> + </varlistentry>
> +
> + </variablelist>
> + </refsect1>
> +
> + <refsect1>
> + <title>See Also</title>
> + <para>
> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
> + <citerefentry><refentrytitle>systemd-resume at .service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
> + <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>
> + </para>
> + </refsect1>
> +
> +</refentry>
> diff --git a/src/resume-generator/Makefile b/src/resume-generator/Makefile
> new file mode 120000
> index 0000000..d0b0e8e
> --- /dev/null
> +++ b/src/resume-generator/Makefile
> @@ -0,0 +1 @@
> +../Makefile
> \ No newline at end of file
> diff --git a/src/resume-generator/resume-generator.c b/src/resume-generator/resume-generator.c
> new file mode 100644
> index 0000000..0f42b3b
> --- /dev/null
> +++ b/src/resume-generator/resume-generator.c
> @@ -0,0 +1,93 @@
> +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
> +
> +/***
> + This file is part of systemd.
> +
> + Copyright 2014 Ivan Shapovalov
> +
> + systemd 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 2.1 of the License, or
> + (at your option) any later version.
> +
> + systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
> +***/
> +
> +#include <stdio.h>
> +#include <errno.h>
> +
> +#include "log.h"
> +#include "util.h"
> +#include "special.h"
> +#include "mkdir.h"
> +#include "unit-name.h"
> +
> +static const char *arg_dest = "/tmp";
> +static char *arg_resume_dev = NULL;
> +
> +static int parse_proc_cmdline_item(const char *key, const char *value) {
> + if (streq(key, "resume") && value) {
> + free(arg_resume_dev);
> + arg_resume_dev = strdup(value);
> + if (!arg_resume_dev)
> + return log_oom();
> + }
> +
> + return 0;
> +}
> +
> +static int process_resume(void) {
> + _cleanup_free_ char *name = NULL, *lnk = NULL;
> +
> + name = unit_name_from_path_instance("systemd-resume", arg_resume_dev, ".service");
> + if (!name)
> + return log_oom();
> +
> + lnk = strjoin(arg_dest, "/" SPECIAL_SYSINIT_TARGET ".wants/", name, NULL);
> + if (!lnk)
> + return log_oom();
> +
> + mkdir_parents_label(lnk, 0755);
> + if (symlink(SYSTEM_DATA_UNIT_PATH "/systemd-resume at .service", lnk) < 0) {
> + log_error("Failed to create symlink %s: %m", lnk);
> + return -errno;
> + }
return 0;
> +}
> +
> +int main(int argc, char *argv[]) {
> + int r = 0;
> +
> + if (argc > 1 && argc != 4) {
> + log_error("This program takes three or no arguments.");
> + return EXIT_FAILURE;
> + }
> +
> + if (argc > 1)
> + arg_dest = argv[1];
> +
> + log_set_target(LOG_TARGET_SAFE);
> + log_parse_environment();
> + log_open();
> +
> + umask(0022);
> +
> + /* Don't even consider resuming outside of initramfs. */
> + if (!in_initrd())
> + return EXIT_SUCCESS;
> +
> + if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
> + return EXIT_FAILURE;
> +
> + if (arg_resume_dev != NULL)
> + r = process_resume();
> +
> + free(arg_resume_dev);
> +
> + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
> +}
> --
> 2.1.0
>
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