1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>debugfs_create_u64</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="debugfs.html#debugfs_interface" title="debugfs interface"><link rel="prev" href="API-debugfs-create-u32.html" title="debugfs_create_u32"><link rel="next" href="API-debugfs-create-x8.html" title="debugfs_create_x8"></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"><span class="phrase">debugfs_create_u64</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-debugfs-create-u32.html">Prev</a>&#160;</td><th width="60%" align="center">debugfs interface</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-debugfs-create-x8.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-debugfs-create-u64"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>debugfs_create_u64 &#8212; 
2     create a debugfs file that is used to read and write an unsigned 64-bit value
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">struct dentry * <b class="fsfunc">debugfs_create_u64 </b>(</code></td><td>const char * <var class="pdparam">name</var>, </td></tr><tr><td>&#160;</td><td>umode_t <var class="pdparam">mode</var>, </td></tr><tr><td>&#160;</td><td>struct dentry * <var class="pdparam">parent</var>, </td></tr><tr><td>&#160;</td><td>u64 * <var class="pdparam">value</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1103427892"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>name</code></em></span></dt><dd><p>
4     a pointer to a string containing the name of the file to create.
5    </p></dd><dt><span class="term"><em class="parameter"><code>mode</code></em></span></dt><dd><p>
6     the permission that the file should have
7    </p></dd><dt><span class="term"><em class="parameter"><code>parent</code></em></span></dt><dd><p>
8     a pointer to the parent dentry for this file.  This should be a
9     directory dentry if set.  If this parameter is <code class="constant">NULL</code>, then the
10     file will be created in the root of the debugfs filesystem.
11    </p></dd><dt><span class="term"><em class="parameter"><code>value</code></em></span></dt><dd><p>
12     a pointer to the variable that the file should read to and write
13     from.
14    </p></dd></dl></div></div><div class="refsect1"><a name="idp1103433076"></a><h2>Description</h2><p>
15   This function creates a file in debugfs with the given name that
16   contains the value of the variable <em class="parameter"><code>value</code></em>.  If the <em class="parameter"><code>mode</code></em> variable is so
17   set, it can be read from, and written to.
18   </p><p>
19
20   This function will return a pointer to a dentry if it succeeds.  This
21   pointer must be passed to the <code class="function">debugfs_remove</code> function when the file is
22   to be removed (no automatic cleanup happens if your module is unloaded,
23   you are responsible here.)  If an error occurs, <code class="constant">NULL</code> will be returned.
24   </p><p>
25
26   If debugfs is not enabled in the kernel, the value -<code class="constant">ENODEV</code> will be
27   returned.  It is not wise to check for this value, but rather, check for
28   <code class="constant">NULL</code> or !<code class="constant">NULL</code> instead as to eliminate the need for #ifdef in the calling
29   code.
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