From 9f103625b145a397e67c3714766775b615c8b587 Mon Sep 17 00:00:00 2001

From: Tobias Hunger <tobias.hunger@gmail.com>

Date: Thu, 9 Oct 2014 21:37:17 +0200

Subject: [PATCH] fstab-generator: Honor mount.usr*= on kernel command line

This allows to configure boot loader entries for systems where the

root and usr filesystems are in different subvolumes (or even on

different drives).

---

 man/systemd-fstab-generator.xml       | 76 ++++++++++++++++++++++++++++-

 src/fstab-generator/fstab-generator.c | 90 +++++++++++++++++++++++++++++++++--

 2 files changed, 160 insertions(+), 6 deletions(-)

diff --git a/man/systemd-fstab-generator.xml b/man/systemd-fstab-generator.xml

index e3cf5d2bfb..65b48eea07 100644

--- a/man/systemd-fstab-generator.xml

+++ b/man/systemd-fstab-generator.xml

@@ -104,9 +104,83 @@

                                 (initrd) while

                                 <varname>fstab=</varname> is

                                 honored by both the main system and

-                                the initrd.  </para></listitem>

+                                the initrd.</para></listitem>

                         </varlistentry>

+                        <varlistentry>

+                                <term><varname>root=</varname></term>

+

+                                <listitem><para>Takes the root filesystem to mount

+                                in the initrd.

+                                <varname>root=</varname> is

+                                honored by the initrd.</para></listitem>

+                        </varlistentry>

+                        <varlistentry>

+                                <term><varname>rootfstype=</varname></term>

+

+                                <listitem><para>Takes the root filesystem type that

+                                will be passed to the mount command.

+                                <varname>rootfstype=</varname> is

+                                honored by the initrd.</para></listitem>

+                        </varlistentry>

+                        <varlistentry>

+                                <term><varname>rootflags=</varname></term>

+

+                                <listitem><para>Takes the root filesystem mount options

+                                to use. <varname>rootflags=</varname> is

+                                honored by the initrd.</para></listitem>

+                        </varlistentry>

+                        <varlistentry>

+                                <term><varname>mount.usr=</varname></term>

+

+                                <listitem><para>Takes the <filename>/usr</filename>

+                                filesystem to be mounted by the initrd. If

+                                <varname>mount.usrfstype=</varname> or

+                                <varname>mount.usrflags=</varname> is set, then

+                                <varname>mount.usr=</varname> will default to the value set in

+                                <varname>root=</varname>.</para>

+

+                                <para>Otherwise this parameter defaults to the

+                                <filename>/usr</filename> entry

+                                found in <filename>/etc/fstab</filename> on the root

+                                filesystem.</para>

+

+                                <para><varname>mount.usr=</varname> is honored by the initrd.

+                                </para></listitem>

+                        </varlistentry>

+                        <varlistentry>

+                                <term><varname>mount.usrfstype=</varname></term>

+

+                                <listitem><para>Takes the <filename>/usr</filename>

+                                filesystem type that will be passed to the mount

+                                command. If <varname>mount.usr=</varname> or

+                                <varname>mount.usrflags=</varname> is set, then

+                                <varname>mount.usrfstype=</varname> will default to the value set in

+                                <varname>rootfstype=</varname>.</para>

+

+                                <para>Otherwise this value will be read from the

+                                <filename>/usr</filename> entry in

+                                <filename>/etc/fstab</filename> on the root filesystem.</para>

+

+                                <para><varname>mount.usrfstype=</varname> is

+                                honored by the initrd.</para></listitem>

+                        </varlistentry>

+                        <varlistentry>

+                                <term><varname>mount.usrflags=</varname></term>

+

+                                <listitem><para>Takes the <filename>/usr</filename>

+                                filesystem mount options to use. If

+                                <varname>mount.usr=</varname> or

+                                <varname>mount.usrfstype=</varname> is set, then

+                                <varname>mount.usrflages=</varname> will default to the value set in

+                                <varname>rootflags=</varname>.</para>

+                                <para>Otherwise this value will be read from the

+                                <filename>/usr</filename> entry in

+                                <filename>/etc/fstab</filename> on the root filesystem.</para>

+

+                                <para><varname>mount.usrflags=</varname> is

+                                honored by the initrd.</para></listitem>

+                        </varlistentry>

                 </variablelist>

         </refsect1>

diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c

index b75bbb7998..32a8f9bd51 100644

--- a/src/fstab-generator/fstab-generator.c

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

@@ -43,6 +43,9 @@ static char *arg_root_what = NULL;

 static char *arg_root_fstype = NULL;

 static char *arg_root_options = NULL;

 static int arg_root_rw = -1;

+static char *arg_usr_what = NULL;

+static char *arg_usr_fstype = NULL;

+static char *arg_usr_options = NULL;

 static int mount_find_pri(struct mntent *me, int *ret) {

@@ -494,12 +497,64 @@ static int add_root_mount(void) {

                          "/proc/cmdline");

 }

+static int add_usr_mount(void) {

+        _cleanup_free_ char *what = NULL;

+        const char *opts;

+

+        if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)

+                return 0;

+

+        if (arg_root_what && !arg_usr_what) {

+                arg_usr_what = strdup(arg_root_what);

+

+                if (!arg_usr_what)

+                        return log_oom();

+        }

+

+        if (arg_root_fstype && !arg_usr_fstype) {

+                arg_usr_fstype = strdup(arg_root_fstype);

+

+                if (!arg_usr_fstype)

+                        return log_oom();

+        }

+

+        if (arg_root_options && !arg_usr_options) {

+                arg_usr_options = strdup(arg_root_options);

+

+                if (!arg_usr_options)

+                        return log_oom();

+        }

+

+        if (!arg_usr_what || !arg_usr_options)

+                return 0;

+

+        what = fstab_node_to_udev_node(arg_usr_what);

+        if (!path_is_absolute(what)) {

+                log_debug("Skipping entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));

+                return -1;

+        }

+

+        opts = arg_usr_options;

+

+        log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));

+        return add_mount(what,

+                         "/sysroot/usr",

+                         arg_usr_fstype,

+                         opts,

+                         1,

+                         false,

+                         false,

+                         false,

+                         SPECIAL_INITRD_ROOT_FS_TARGET,

+                         "/proc/cmdline");

+}

+

 static int parse_proc_cmdline_item(const char *key, const char *value) {

         int r;

-        /* root= and roofstype= may occur more than once, the last

-         * instance should take precedence.  In the case of multiple

-         * rootflags= the arguments should be concatenated */

+        /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last

+         * instance should take precedence.  In the case of multiple rootflags=

+         * or usrflags= the arguments should be concatenated */

         if (STR_IN_SET(key, "fstab", "rd.fstab") && value) {

@@ -531,6 +586,28 @@ static int parse_proc_cmdline_item(const char *key, const char *value) {

                 free(arg_root_options);

                 arg_root_options = o;

+        } else if (streq(key, "mount.usr") && value) {

+

+                if (free_and_strdup(&arg_usr_what, value) < 0)

+                        return log_oom();

+

+        } else if (streq(key, "mount.usrfstype") && value) {

+

+                if (free_and_strdup(&arg_usr_fstype, value) < 0)

+                        return log_oom();

+

+        } else if (streq(key, "mount.usrflags") && value) {

+                char *o;

+

+                o = arg_usr_options ?

+                        strjoin(arg_usr_options, ",", value, NULL) :

+                        strdup(value);

+                if (!o)

+                        return log_oom();

+

+                free(arg_usr_options);

+                arg_usr_options = o;

+

         } else if (streq(key, "rw") && !value)

                 arg_root_rw = true;

         else if (streq(key, "ro") && !value)

@@ -559,9 +636,12 @@ int main(int argc, char *argv[]) {

         if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)

                 return EXIT_FAILURE;

-        /* Always honour root= in the kernel command line if we are in an initrd */

-        if (in_initrd())

+        /* Always honour root= and usr= in the kernel command line if we are in an initrd */

+        if (in_initrd()) {

                 r = add_root_mount();

+                if (r == 0)

+                        r = add_usr_mount();

+        }

         /* Honour /etc/fstab only when that's enabled */

         if (arg_fstab_enabled) {