man: document /var/tmp/ and /var/ handling in systemd-gpt-auto-generator man page

And some other fixes and additions.

man/systemd-gpt-auto-generator.xml

@@ -17,11 +17,9 @@
 
   <refnamediv>
     <refname>systemd-gpt-auto-generator</refname>
-    <refpurpose>Generator for automatically discovering
+    <refpurpose>Generator for automatically discovering and mounting root, <filename>/home/</filename>,
-    and mounting root, <filename>/home</filename> and
+    <filename>/srv/</filename>, <filename>/var/</filename> and <filename>/var/tmp/</filename> partitions, as
-    <filename>/srv</filename> partitions, as well as
+    well as discovering and enabling swap partitions, based on GPT partition type GUIDs.</refpurpose>
-    discovering and enabling swap partitions, based on GPT
-    partition type GUIDs.</refpurpose>
   </refnamediv>
 
   <refsynopsisdiv>
@@ -32,11 +30,11 @@
     <title>Description</title>
 
     <para><filename>systemd-gpt-auto-generator</filename> is a unit generator that automatically discovers
-    root, <filename>/home/</filename>, <filename>/srv/</filename>, the EFI System Partition, the Extended
+    root, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>,
-    Boot Loader Partition and swap partitions and creates mount and swap units for them, based on the
+    <filename>/var/tmp/</filename>, the EFI System Partition, the Extended Boot Loader Partition and swap
-    partition type GUIDs of GUID partition tables (GPT), see <ulink
+    partitions and creates mount and swap units for them, based on the partition type GUIDs of GUID partition
-    url="https://uefi.org/specifications">UEFI Specification</ulink>, chapter 5. It implements the <ulink
+    tables (GPT), see <ulink url="https://uefi.org/specifications">UEFI Specification</ulink>, chapter 5. It
-    url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions
+    implements the <ulink url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions
     Specification</ulink>. Note that this generator has no effect on non-GPT systems, and on specific mount
     points that are directories already containing files. Also, on systems where the units are explicitly
     configured (for example, listed in <citerefentry
@@ -45,10 +43,12 @@
     created.</para>
 
     <para>This generator will only look for the root partition on the same physical disk the EFI System
-    Partition (ESP) is located on. Note that support from the boot loader is required: EFI variable
+    Partition (ESP) is located on. Note that support from the boot loader is required: the EFI variable
-    <varname>LoaderDevicePartUUID-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f</varname> is used to determine from
+    <varname>LoaderDevicePartUUID</varname> of the <constant>4a67b082-0a4c-41cf-b6c7-440b29bb8c4f</constant>
-    which partition, and hence the disk from which the system was booted. If the boot loader does not set
+    vendor UUID is used to determine from which partition, and hence the disk from which the system was
-    this variable, this generator will not be able to autodetect the root partition.</para>
+    booted. If the boot loader does not set this variable, this generator will not be able to autodetect the
+    root partition. See the <ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader
+    Interface</ulink> for details.</para>
 
     <para>Similarly, this generator will only look for the other partitions on the same physical disk as the
     root partition. In this case, boot loader support is not required. These partitions will not be searched
@@ -113,13 +113,25 @@
             <entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
             <entry>Home Partition</entry>
             <entry><filename>/home/</filename></entry>
-            <entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home</filename>.</entry>
+            <entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home/</filename>.</entry>
           </row>
           <row>
             <entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
             <entry>Server Data Partition</entry>
             <entry><filename>/srv/</filename></entry>
-            <entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv</filename>.</entry>
+            <entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv/</filename>.</entry>
+          </row>
+          <row>
+            <entry>4d21b016-b534-45c2-a9fb-5c16e091fd2d</entry>
+            <entry>Variable Data Partition</entry>
+            <entry><filename>/var/</filename></entry>
+            <entry>The first variable data partition on the disk the root partition is located on is mounted to <filename>/var/</filename> — under the condition its partition UUID matches the first 128 bit of the HMAC-SHA256 of the GPT type uuid of this partition keyed by the machine ID of the installation stored in <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</entry>
+          </row>
+          <row>
+            <entry>7ec6f557-3bc5-4aca-b293-16ef5df639d1</entry>
+            <entry>Temporary Data Partition</entry>
+            <entry><filename>/var/tmp/</filename></entry>
+            <entry>The first temporary data partition on the disk the root partition is located on is mounted to <filename>/var/tmp/</filename>.</entry>
           </row>
           <row>
             <entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
@@ -131,13 +143,13 @@
             <entry>c12a7328-f81f-11d2-ba4b-00a0c93ec93b</entry>
             <entry>EFI System Partition (ESP)</entry>
             <entry><filename>/efi/</filename> or <filename>/boot/</filename></entry>
-            <entry>The first ESP located on the disk the root partition is located on is mounted to <filename>/boot</filename> or <filename>/efi</filename>, see below.</entry>
+            <entry>The first ESP located on the disk the root partition is located on is mounted to <filename>/boot/</filename> or <filename>/efi/</filename>, see below.</entry>
           </row>
           <row>
             <entry>bc13c2ff-59e6-4262-a352-b275fd6f7172</entry>
             <entry>Extended Boot Loader Partition</entry>
             <entry><filename>/boot/</filename></entry>
-            <entry>The first Extended Boot Loader Partition is mounted to <filename>/boot</filename>, see below.</entry>
+            <entry>The first Extended Boot Loader Partition is mounted to <filename>/boot/</filename>, see below.</entry>
           </row>
         </tbody>
       </tgroup>
@@ -164,14 +176,14 @@
           <row>
             <entry><constant>GPT_FLAG_READ_ONLY</constant></entry>
             <entry>0x1000000000000000</entry>
-            <entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, Extended Boot Loader Partition</entry>
+            <entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>, <filename>/var/tmp/</filename>, Extended Boot Loader Partition</entry>
             <entry>Partition is mounted read-only</entry>
           </row>
 
           <row>
             <entry><constant>GPT_FLAG_NO_AUTO</constant></entry>
             <entry>0x8000000000000000</entry>
-            <entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, Extended Boot Loader Partition</entry>
+            <entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>, <filename>/var/tmp/</filename>, Extended Boot Loader Partition</entry>
             <entry>Partition is not mounted automatically</entry>
           </row>
 
@@ -185,11 +197,12 @@
       </tgroup>
     </table>
 
-    <para>The <filename>/home/</filename> and <filename>/srv/</filename> partitions may be encrypted in LUKS
+    <para>The <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename> and
-    format. In this case, a device mapper device is set up under the names
+    <filename>/var/tmp/</filename> partitions may be encrypted in LUKS format. In this case, a device mapper
-    <filename>/dev/mapper/home</filename> and <filename>/dev/mapper/srv</filename>. Note that this might
+    device is set up under the names <filename>/dev/mapper/home</filename>,
-    create conflicts if the same partition is listed in <filename>/etc/crypttab</filename> with a different
+    <filename>/dev/mapper/srv</filename>, <filename>/dev/mapper/var</filename> and
-    device mapper device name.</para>
+    <filename>/dev/mapper/tmp</filename>. Note that this might create conflicts if the same partition is
+    listed in <filename>/etc/crypttab</filename> with a different device mapper device name.</para>
 
     <para>When systemd is running in the initrd the <filename>/</filename> partition may be encrypted in LUKS
       format as well. In this case, a device mapper device is set up under the name <filename>/dev/mapper/root</filename>,
@@ -209,7 +222,7 @@
 
     <para>If the disk contains an Extended Boot Loader partition, as defined in the <ulink
     url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>, it is made
-    available at <filename>/boot</filename> (by means of an automount point, similar to the ESP, see
+    available at <filename>/boot/</filename> (by means of an automount point, similar to the ESP, see
     above). If both an EFI System Partition and an Extended Boot Loader partition exist the latter is
     preferably mounted to <filename>/boot/</filename>. Make sure to create both <filename>/efi/</filename>
     and <filename>/boot/</filename> to ensure both partitions are mounted.</para>
@@ -269,6 +282,7 @@
       <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>