1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>d_obtain_root</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="the_directory_cache.html" title="The Directory Cache"><link rel="prev" href="API-d-obtain-alias.html" title="d_obtain_alias"><link rel="next" href="API-d-add-ci.html" title="d_add_ci"></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">d_obtain_root</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-d-obtain-alias.html">Prev</a>&#160;</td><th width="60%" align="center">The Directory Cache</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-d-add-ci.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-d-obtain-root"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>d_obtain_root &#8212; 
2     find or allocate a dentry for a given inode
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">d_obtain_root </b>(</code></td><td>struct inode * <var class="pdparam">inode</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1101477788"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>inode</code></em></span></dt><dd><p>
4     inode to allocate the dentry for
5    </p></dd></dl></div></div><div class="refsect1"><a name="idp1101479364"></a><h2>Description</h2><p>
6   Obtain an IS_ROOT dentry for the root of a filesystem.
7   </p><p>
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9   We must ensure that directory inodes only ever have one dentry.  If a
10   dentry is found, that is returned instead of allocating a new one.
11   </p><p>
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13   On successful return, the reference to the inode has been transferred
14   to the dentry.  In case of an error the reference on the inode is
15   released.  A <code class="constant">NULL</code> or IS_ERR inode may be passed in and will be the
16   error will be propagate to the return value, with a <code class="constant">NULL</code> <em class="parameter"><code>inode</code></em>
17   replaced by ERR_PTR(-ESTALE).
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