1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>get_request</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux Kernel API"><link rel="up" href="blkdev.html" title="Chapter&#160;14.&#160;Block Devices"><link rel="prev" href="API---get-request.html" title="__get_request"><link rel="next" href="API-blk-attempt-plug-merge.html" title="blk_attempt_plug_merge"></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">get_request</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API---get-request.html">Prev</a>&#160;</td><th width="60%" align="center">Chapter&#160;14.&#160;Block Devices</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-blk-attempt-plug-merge.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-get-request"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>get_request &#8212; 
2     get a free request
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 request * <b class="fsfunc">get_request </b>(</code></td><td>struct request_queue * <var class="pdparam">q</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">rw_flags</var>, </td></tr><tr><td>&#160;</td><td>struct bio * <var class="pdparam">bio</var>, </td></tr><tr><td>&#160;</td><td>gfp_t <var class="pdparam">gfp_mask</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1128238364"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>q</code></em></span></dt><dd><p>
4     request_queue to allocate request from
5    </p></dd><dt><span class="term"><em class="parameter"><code>rw_flags</code></em></span></dt><dd><p>
6     RW and SYNC flags
7    </p></dd><dt><span class="term"><em class="parameter"><code>bio</code></em></span></dt><dd><p>
8     bio to allocate request for (can be <code class="constant">NULL</code>)
9    </p></dd><dt><span class="term"><em class="parameter"><code>gfp_mask</code></em></span></dt><dd><p>
10     allocation mask
11    </p></dd></dl></div></div><div class="refsect1"><a name="idp1128243260"></a><h2>Description</h2><p>
12   Get a free request from <em class="parameter"><code>q</code></em>.  If <code class="constant">__GFP_WAIT</code> is set in <em class="parameter"><code>gfp_mask</code></em>, this
13   function keeps retrying under memory pressure and fails iff <em class="parameter"><code>q</code></em> is dead.
14   </p><p>
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16   Must be called with <em class="parameter"><code>q</code></em>-&gt;queue_lock held and,
17   Returns ERR_PTR on failure, with <em class="parameter"><code>q</code></em>-&gt;queue_lock held.
18   Returns request pointer on success, with <em class="parameter"><code>q</code></em>-&gt;queue_lock *not held*.
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