1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Data Types</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux Filesystems API"><link rel="up" href="LinuxJDBAPI.html" title="Chapter 6. The Linux Journalling API"><link rel="prev" href="LinuxJDBAPI.html" title="Chapter 6. The Linux Journalling API"><link rel="next" href="API-typedef-handle-t.html" title="typedef handle_t"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Data Types</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="LinuxJDBAPI.html">Prev</a> </td><th width="60%" align="center">Chapter 6. The Linux Journalling API</th><td width="20%" align="right"> <a accesskey="n" href="API-typedef-handle-t.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="data_types"></a>Data Types</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="data_types.html#structures">Structures</a></span></dt></dl></div><p> 2 The journalling layer uses typedefs to 'hide' the concrete definitions 3 of the structures used. As a client of the JBD layer you can 4 just rely on the using the pointer as a magic cookie of some sort. 5 6 Obviously the hiding is not enforced as this is 'C'. 7 </p><div class="sect2"><div class="titlepage"><div><div><h3 class="title"><a name="structures"></a>Structures</h3></div></div></div><div class="toc"><dl class="toc"><dt><span class="refentrytitle"><a href="API-typedef-handle-t.html"><span class="phrase">typedef handle_t</span></a></span><span class="refpurpose"> — 8 The handle_t type represents a single atomic update being performed by some process. 9 </span></dt><dt><span class="refentrytitle"><a href="API-typedef-journal-t.html"><span class="phrase">typedef journal_t</span></a></span><span class="refpurpose"> — 10 The journal_t maintains all of the journaling state information for a single filesystem. 11 </span></dt><dt><span class="refentrytitle"><a href="API-struct-handle-s.html"><span class="phrase">struct handle_s</span></a></span><span class="refpurpose"> — 12 this is the concrete type associated with handle_t. 13 </span></dt><dt><span class="refentrytitle"><a href="API-struct-journal-s.html"><span class="phrase">struct journal_s</span></a></span><span class="refpurpose"> — 14 this is the concrete type associated with journal_t. 15 </span></dt></dl></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="LinuxJDBAPI.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="LinuxJDBAPI.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="API-typedef-handle-t.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 6. The Linux Journalling API </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span class="phrase">typedef handle_t</span></td></tr></table></div></body></html> 16