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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>relay_open</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="The Linux Kernel API" /><link rel="up" href="ch07.html#id2659585" title="relay interface" /><link rel="prev" href="re269.html" title="relay_reset" /><link rel="next" href="re271.html" title="relay_switch_subbuf" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>relay_open</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re269.html">Prev</a> </td><th width="60%" align="center">relay interface</th><td width="20%" align="right"> <a accesskey="n" href="re271.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="relay_open"><a id="API-relay-open"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>relay_open —
create a new relay channel
</p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">struct rchan * <b class="fsfunc">relay_open </b>(</code></td><td>const char * <var class="pdparam">base_filename</var>, </td></tr><tr><td> </td><td>struct dentry * <var class="pdparam">parent</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">subbuf_size</var>, </td></tr><tr><td> </td><td>size_t <var class="pdparam">n_subbufs</var>, </td></tr><tr><td> </td><td>struct rchan_callbacks * <var class="pdparam">cb</var>, </td></tr><tr><td> </td><td>void * <var class="pdparam">private_data</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id2659947"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>base_filename</code></em></span></dt><dd><p>
base name of files to create, <code class="constant">NULL</code> for buffering only
</p></dd><dt><span class="term"><em class="parameter"><code>parent</code></em></span></dt><dd><p>
dentry of parent directory, <code class="constant">NULL</code> for root directory or buffer
</p></dd><dt><span class="term"><em class="parameter"><code>subbuf_size</code></em></span></dt><dd><p>
size of sub-buffers
</p></dd><dt><span class="term"><em class="parameter"><code>n_subbufs</code></em></span></dt><dd><p>
number of sub-buffers
</p></dd><dt><span class="term"><em class="parameter"><code>cb</code></em></span></dt><dd><p>
client callback functions
</p></dd><dt><span class="term"><em class="parameter"><code>private_data</code></em></span></dt><dd><p>
user-defined data
</p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id2660068"></a><h2>Description</h2><p>
Returns channel pointer if successful, <code class="constant">NULL</code> otherwise.
</p><p>
Creates a channel buffer for each cpu using the sizes and
attributes specified. The created channel buffer files
will be named base_filename0...base_filenameN-1. File
permissions will be <code class="constant">S_IRUSR</code>.
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re269.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch07.html#id2659585">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re271.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>relay_reset</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>relay_switch_subbuf</span></td></tr></table></div></body></html>
