From d2c68822c47e37b582820f45b496b2e7d1f9e642 Mon Sep 17 00:00:00 2001

From: Ivan Shapovalov <intelfx100@gmail.com>

Date: Wed, 27 Aug 2014 00:17:45 +0400

Subject: [PATCH] hibernate-resume-generator: add a generator for instantiating

 the resume unit.

hibernate-resume-generator understands resume= kernel command line parameter

and instantiates the systemd-resume@.service accordingly if it is passed.

This enables resume from hibernation using device specified on the kernel

command line, and it may be specified either as "/dev/disk/by-foo/bar"

or "FOO=bar", not only "/dev/sdXY" which is understood by the in-kernel

implementation.

So now resume= is brought on par with root= in terms of possible ways to

specify a device.

---

 .gitignore                                 |  1 +

 Makefile-man.am                            |  2 +

 Makefile.am                                | 11 +++-

 man/kernel-command-line.xml                | 14 ++++-

 man/systemd-hibernate-resume-generator.xml | 93 +++++++++++++++++++++++++++++

 src/resume-generator/Makefile              |  1 +

 src/resume-generator/resume-generator.c    | 95 ++++++++++++++++++++++++++++++

 7 files changed, 215 insertions(+), 2 deletions(-)

 create mode 100644 man/systemd-hibernate-resume-generator.xml

 create mode 120000 src/resume-generator/Makefile

 create mode 100644 src/resume-generator/resume-generator.c

diff --git a/.gitignore b/.gitignore

index 0b5608ccf9..8aed0b9ba6 100644

--- a/.gitignore

+++ b/.gitignore

@@ -76,6 +76,7 @@

 /systemd-gnome-ask-password-agent

 /systemd-gpt-auto-generator

 /systemd-hibernate-resume

+/systemd-hibernate-resume-generator

 /systemd-hostnamed

 /systemd-inhibit

 /systemd-initctl

diff --git a/Makefile-man.am b/Makefile-man.am

index 09a10383a9..5c27937152 100644

--- a/Makefile-man.am

+++ b/Makefile-man.am

@@ -70,6 +70,7 @@ MANPAGES += \

 	man/systemd-getty-generator.8 \

 	man/systemd-gpt-auto-generator.8 \

 	man/systemd-halt.service.8 \

+	man/systemd-hibernate-resume-generator.8 \

 	man/systemd-hibernate-resume@.service.8 \

 	man/systemd-inhibit.1 \

 	man/systemd-initctl.service.8 \

@@ -1625,6 +1626,7 @@ EXTRA_DIST += \

 	man/systemd-getty-generator.xml \

 	man/systemd-gpt-auto-generator.xml \

 	man/systemd-halt.service.xml \

+	man/systemd-hibernate-resume-generator.xml \

 	man/systemd-hibernate-resume@.service.xml \

 	man/systemd-hostnamed.service.xml \

 	man/systemd-inhibit.xml \

diff --git a/Makefile.am b/Makefile.am

index a487caa7bc..cbdf551fa8 100644

--- a/Makefile.am

+++ b/Makefile.am

@@ -385,7 +385,8 @@ systemgenerator_PROGRAMS = \

 	systemd-getty-generator \

 	systemd-fstab-generator \

 	systemd-system-update-generator \

-	systemd-debug-generator

+	systemd-debug-generator \

+	systemd-hibernate-resume-generator

 dist_bashcompletion_DATA = \

 	shell-completion/bash/busctl \

@@ -2146,6 +2147,14 @@ systemd_system_update_generator_LDADD = \

 	libsystemd-label.la \

 	libsystemd-shared.la

+# ------------------------------------------------------------------------------

+systemd_hibernate_resume_generator_SOURCES = \

+	src/resume-generator/resume-generator.c

+

+systemd_hibernate_resume_generator_LDADD = \

+	libsystemd-label.la \

+	libsystemd-shared.la

+

 if ENABLE_EFI

 # ------------------------------------------------------------------------------

 systemgenerator_PROGRAMS +=  \

diff --git a/man/kernel-command-line.xml b/man/kernel-command-line.xml

index 36428aaa94..d872e6d5b9 100644

--- a/man/kernel-command-line.xml

+++ b/man/kernel-command-line.xml

@@ -351,6 +351,17 @@

                                 </listitem>

                         </varlistentry>

+                        <varlistentry>

+                                <term><varname>resume=</varname></term>

+

+                                <listitem>

+                                        <para>Enables resume from hibernation

+                                        using the specified device.

+                                        All <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like

+                                        pathes are supported. For details, see

+                                        <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

+                                </listitem>

+                        </varlistentry>

                 </variablelist>

         </refsect1>

@@ -373,7 +384,8 @@

                           <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@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

-                          <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>

+                          <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

+                          <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>

                   </para>

         </refsect1>

diff --git a/man/systemd-hibernate-resume-generator.xml b/man/systemd-hibernate-resume-generator.xml

new file mode 100644

index 0000000000..1a4b99ced4

--- /dev/null

+++ b/man/systemd-hibernate-resume-generator.xml

@@ -0,0 +1,93 @@

+

+

+

+

+  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-hibernate-resume-generator">

+

+        <refentryinfo>

+                <title>systemd-hibernate-resume-generator</title>

+                <productname>systemd</productname>

+

+                <authorgroup>

+                        <author>

+                                <contrib>Developer</contrib>

+                                <firstname>Ivan</firstname>

+                                <surname>Shapovalov</surname>

+                                <email>intelfx100@gmail.com</email>

+                        </author>

+                </authorgroup>

+        </refentryinfo>

+

+        <refmeta>

+                <refentrytitle>systemd-hibernate-resume-generator</refentrytitle>

+                <manvolnum>8</manvolnum>

+        </refmeta>

+

+        <refnamediv>

+                <refname>systemd-hibernate-resume-generator</refname>

+                <refpurpose>Unit generator for resume= kernel parameter</refpurpose>

+        </refnamediv>

+

+        <refsynopsisdiv>

+                <para><filename>/usr/lib/systemd/system-generators/systemd-hibernate-resume-generator</filename></para>

+        </refsynopsisdiv>

+

+        <refsect1>

+                <title>Description</title>

+

+                <para><filename>systemd-hibernate-resume-generator</filename> is

+                a generator that instantiates

+                <citerefentry><refentrytitle>systemd-hibernate-resume@.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-hibernate-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. Both persistent block device pathes like

+                                <filename>/dev/disk/by-foo/bar</filename> and

+                                <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-style

+                                specifiers like <literal>FOO=bar</literal>

+                                are supported.</para></listitem>

+                        </varlistentry>

+

+                </variablelist>

+        </refsect1>

+

+        <refsect1>

+                <title>See Also</title>

+                <para>

+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

+                        <citerefentry><refentrytitle>systemd-hibernate-resume@.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 0000000000..d0b0e8e008

--- /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 0000000000..f40721662e

--- /dev/null

+++ b/src/resume-generator/resume-generator.c

@@ -0,0 +1,95 @@

+/*-*- 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 = fstab_node_to_udev_node(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-hibernate-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-hibernate-resume@.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;

+}