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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>debugfs_create_blob</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="Linux Filesystems API" /><link rel="up" href="ch04.html#debugfs_interface" title="debugfs interface" /><link rel="prev" href="re170.html" title="debugfs_create_bool" /><link rel="next" href="ch05.html" title="Chapter 5. The Linux Journalling API" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>debugfs_create_blob</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re170.html">Prev</a> </td><th width="60%" align="center">debugfs interface</th><td width="20%" align="right"> <a accesskey="n" href="ch05.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="debugfs_create_blob"><a id="API-debugfs-create-blob"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>debugfs_create_blob —
create a debugfs file that is used to read a binary blob
</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 dentry * <b class="fsfunc">debugfs_create_blob </b>(</code></td><td>const char * <var class="pdparam">name</var>, </td></tr><tr><td> </td><td>mode_t <var class="pdparam">mode</var>, </td></tr><tr><td> </td><td>struct dentry * <var class="pdparam">parent</var>, </td></tr><tr><td> </td><td>struct debugfs_blob_wrapper * <var class="pdparam">blob</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Arguments"><a id="id3124131"></a><h2>Arguments</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>name</code></em></span></dt><dd><p>
a pointer to a string containing the name of the file to create.
</p></dd><dt><span class="term"><em class="parameter"><code>mode</code></em></span></dt><dd><p>
the permission that the file should have
</p></dd><dt><span class="term"><em class="parameter"><code>parent</code></em></span></dt><dd><p>
a pointer to the parent dentry for this file. This should be a
directory dentry if set. If this parameter is <code class="constant">NULL</code>, then the
file will be created in the root of the debugfs filesystem.
</p></dd><dt><span class="term"><em class="parameter"><code>blob</code></em></span></dt><dd><p>
a pointer to a struct debugfs_blob_wrapper which contains a pointer
to the blob data and the size of the data.
</p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id3124218"></a><h2>Description</h2><p>
This function creates a file in debugfs with the given name that exports
<em class="parameter"><code>blob</code></em>->data as a binary blob. If the <em class="parameter"><code>mode</code></em> variable is so set it can be
read from. Writing is not supported.
</p><p>
This function will return a pointer to a dentry if it succeeds. This
pointer must be passed to the <code class="function">debugfs_remove</code> function when the file is
to be removed (no automatic cleanup happens if your module is unloaded,
you are responsible here.) If an error occurs, <code class="constant">NULL</code> will be returned.
</p><p>
If debugfs is not enabled in the kernel, the value -<code class="constant">ENODEV</code> will be
returned. It is not wise to check for this value, but rather, check for
<code class="constant">NULL</code> or !<code class="constant">NULL</code> instead as to eliminate the need for #ifdef in the calling
code.
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re170.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch04.html#debugfs_interface">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch05.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>debugfs_create_bool</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 5. The Linux Journalling API</td></tr></table></div></body></html>
