ipc/kdbus/Documentation/kdbus.fs.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
   5 <refentry id="kdbus_fs">
   6
   7   <refentryinfo>
   8     <title>kdbus.fs</title>
   9     <productname>kdbus.fs</productname>
  10   </refentryinfo>
  11
  12   <refmeta>
  13     <refentrytitle>kdbus.fs</refentrytitle>
  14     <manvolnum>7</manvolnum>
  15   </refmeta>
  16
  17   <refnamediv>
  18     <refname>kdbus.fs</refname>
  19     <refpurpose>kdbus file system</refpurpose>
  20   </refnamediv>
  21
  22   <refsect1>
  23     <title>File-system Layout</title>
  24
  25     <para>
  26       The <emphasis>kdbusfs</emphasis> pseudo filesystem provides access to
  27       kdbus entities, such as <emphasis>buses</emphasis> and
  28       <emphasis>endpoints</emphasis>. Each time the filesystem is mounted,
  29       a new, isolated kdbus instance is created, which is independent from the
  30       other instances.
  31     </para>
  32     <para>
  33       The system-wide standard mount point for <emphasis>kdbusfs</emphasis> is
  34       <constant>/sys/fs/kdbus</constant>.
  35     </para>
  36
  37     <para>
  38       Buses are represented as directories in the file system layout, whereas
  39       endpoints are exposed as files inside these directories. At the top-level,
  40       a <emphasis>control</emphasis> node is present, which can be opened to
  41       create new buses via the <constant>KDBUS_CMD_BUS_MAKE</constant> ioctl.
  42       Each <emphasis>bus</emphasis> shows a default endpoint called
  43       <varname>bus</varname>, which can be opened to either create a connection
  44       with the <constant>KDBUS_CMD_HELLO</constant> ioctl, or to create new
  45       custom endpoints for the bus with
  46       <constant>KDBUS_CMD_ENDPOINT_MAKE</constant>. See
  47       <citerefentry>
  48         <refentrytitle>kdbus.bus</refentrytitle>
  49         <manvolnum>7</manvolnum>
  50       </citerefentry>,
  51       <citerefentry>
  52         <refentrytitle>kdbus.connection</refentrytitle>
  53         <manvolnum>7</manvolnum>
  54       </citerefentry> and
  55       <citerefentry>
  56         <refentrytitle>kdbus.endpoint</refentrytitle>
  57         <manvolnum>7</manvolnum>
  58       </citerefentry>
  59       for more details.
  60     </para>
  61
  62     <para>Following, you can see an example layout of the
  63     <emphasis>kdbusfs</emphasis> filesystem:</para>
  64
  65 <programlisting>
  66         /sys/fs/kdbus/                          ; mount-point
  67         |-- 0-system                            ; bus directory
  68         |   |-- bus                             ; default endpoint
  69         |   `-- 1017-custom                     ; custom endpoint
  70         |-- 1000-user                           ; bus directory
  71         |   |-- bus                             ; default endpoint
  72         |   |-- 1000-service-A                  ; custom endpoint
  73         |   `-- 1000-service-B                  ; custom endpoint
  74         `-- control                             ; control file
  75 </programlisting>
  76   </refsect1>
  77
  78   <refsect1>
  79     <title>Mounting instances</title>
  80     <para>
  81       In order to get a new and separate kdbus environment, a new instance
  82       of <emphasis>kdbusfs</emphasis> can be mounted like this:
  83     </para>
  84 <programlisting>
  85   # mount -t kdbusfs kdbusfs /tmp/new_kdbus/
  86 </programlisting>
  87   </refsect1>
  88
  89   <refsect1>
  90     <title>See Also</title>
  91     <simplelist type="inline">
  92       <member>
  93         <citerefentry>
  94           <refentrytitle>kdbus</refentrytitle>
  95           <manvolnum>7</manvolnum>
  96         </citerefentry>
  97       </member>
  98       <member>
  99         <citerefentry>
 100           <refentrytitle>kdbus.bus</refentrytitle>
 101           <manvolnum>7</manvolnum>
 102         </citerefentry>
 103       </member>
 104       <member>
 105         <citerefentry>
 106           <refentrytitle>kdbus.connection</refentrytitle>
 107           <manvolnum>7</manvolnum>
 108         </citerefentry>
 109       </member>
 110       <member>
 111         <citerefentry>
 112           <refentrytitle>kdbus.endpoint</refentrytitle>
 113           <manvolnum>7</manvolnum>
 114         </citerefentry>
 115       </member>
 116       <member>
 117         <citerefentry>
 118           <refentrytitle>mount</refentrytitle>
 119           <manvolnum>8</manvolnum>
 120         </citerefentry>
 121       </member>
 122     </simplelist>
 123   </refsect1>
 124 </refentry>