Merge pull request #5255 from poettering/percent-escape

fstab-generator: Options= applies specifier expansion

man/systemd.mount.xml

@@ -337,14 +337,12 @@
 
       <varlistentry>
         <term><varname>What=</varname></term>
-        <listitem><para>Takes an absolute path of a device node, file
+        <listitem><para>Takes an absolute path of a device node, file or other resource to mount. See <citerefentry
-        or other resource to mount. See
+        project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry> for details. If
-        <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        this refers to a device node, a dependency on the respective device unit is automatically created. (See
-        for details. If this refers to a device node, a dependency on
+        <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more
-        the respective device unit is automatically created. (See
+        information.) This option is mandatory. Note that the usual specifier expansion is applied to this setting,
-        <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+        literal percent characters should hence be written as <literal>%%</literal>.</para></listitem>
-        for more information.) This option is
-        mandatory.</para></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -366,9 +364,9 @@
       <varlistentry>
         <term><varname>Options=</varname></term>
 
-        <listitem><para>Mount options to use when mounting. This takes
+        <listitem><para>Mount options to use when mounting. This takes a comma-separated list of options. This setting
-        a comma-separated list of options. This setting is
+        is optional. Note that the usual specifier expansion is applied to this setting, literal percent characters
-        optional.</para></listitem>
+        should hence be written as <literal>%%</literal>.</para></listitem>
       </varlistentry>
 
       <varlistentry>

man/systemd.swap.xml

@@ -170,17 +170,15 @@
 
       <varlistentry>
         <term><varname>What=</varname></term>
-        <listitem><para>Takes an absolute path of a device node or
+        <listitem><para>Takes an absolute path of a device node or file to use for paging. See <citerefentry
-        file to use for paging. See
+        project='man-pages'><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
-        <citerefentry project='man-pages'><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+        details. If this refers to a device node, a dependency on the respective device unit is automatically
-        for details. If this refers to a device node, a dependency on
+        created. (See
-        the respective device unit is automatically created. (See
+        <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more
-        <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+        information.) If this refers to a file, a dependency on the respective mount unit is automatically
-        for more information.) If this refers to a file, a dependency
+        created. (See <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
-        on the respective mount unit is automatically created. (See
+        for more information.) This option is mandatory. Note that the usual specifier expansion is applied to this
-        <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+        setting, literal percent characters should hence be written as <literal>%%</literal>.</para></listitem>
-        for more information.) This option is
-        mandatory.</para></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -195,12 +193,11 @@
       <varlistentry>
         <term><varname>Options=</varname></term>
 
-        <listitem><para>May contain an option string for the swap
+        <listitem><para>May contain an option string for the swap device. This may be used for controlling discard
-        device. This may be used for controlling discard options among
+        options among other functionality, if the swap backing device supports the discard or trim operation. (See
-        other functionality, if the swap backing device supports the
-        discard or trim operation. (See
         <citerefentry project='man-pages'><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
-        for more information.) </para></listitem>
+        for more information.) Note that the usual specifier expansion is applied to this setting, literal percent
+        characters should hence be written as <literal>%%</literal>.</para></listitem>
       </varlistentry>
 
       <varlistentry>

src/fstab-generator/fstab-generator.c

@@ -57,6 +57,34 @@ static char *arg_usr_fstype = NULL;
 static char *arg_usr_options = NULL;
 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
 
+static int write_options(FILE *f, const char *options) {
+        _cleanup_free_ char *o = NULL;
+
+        if (isempty(options))
+                return 0;
+
+        if (streq(options, "defaults"))
+                return 0;
+
+        o = strreplace(options, "%", "%%");
+        if (!o)
+                return log_oom();
+
+        fprintf(f, "Options=%s\n", o);
+        return 1;
+}
+
+static int write_what(FILE *f, const char *what) {
+        _cleanup_free_ char *w = NULL;
+
+        w = strreplace(what, "%", "%%");
+        if (!w)
+                return log_oom();
+
+        fprintf(f, "What=%s\n", w);
+        return 1;
+}
+
 static int add_swap(
                 const char *what,
                 struct mntent *me,
@@ -96,17 +124,19 @@ static int add_swap(
                                        "Failed to create unit file %s: %m",
                                        unit);
 
-        fprintf(f,
+        fputs("# Automatically generated by systemd-fstab-generator\n\n"
-                "# Automatically generated by systemd-fstab-generator\n\n"
               "[Unit]\n"
               "SourcePath=/etc/fstab\n"
               "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\n"
-                "[Swap]\n"
+              "[Swap]\n", f);
-                "What=%s\n",
-                what);
 
-        if (!isempty(me->mnt_opts) && !streq(me->mnt_opts, "defaults"))
+        r = write_what(f, what);
-                fprintf(f, "Options=%s\n", me->mnt_opts);
+        if (r < 0)
+                return r;
+
+        r = write_options(f, me->mnt_opts);
+        if (r < 0)
+                return r;
 
         r = fflush_and_check(f);
         if (r < 0)
@@ -331,11 +361,13 @@ static int add_mount(
         fprintf(f,
                 "\n"
                 "[Mount]\n"
-                "What=%s\n"
                 "Where=%s\n",
-                what,
                 where);
 
+        r = write_what(f, what);
+        if (r < 0)
+                return r;
+
         if (!isempty(fstype) && !streq(fstype, "auto"))
                 fprintf(f, "Type=%s\n", fstype);
 
@@ -347,8 +379,9 @@ static int add_mount(
         if (r < 0)
                 return r;
 
-        if (!isempty(filtered) && !streq(filtered, "defaults"))
+        r = write_options(f, filtered);
-                fprintf(f, "Options=%s\n", filtered);
+        if (r < 0)
+                return r;
 
         r = fflush_and_check(f);
         if (r < 0)