1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>blk_update_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-blk-fetch-request.html" title="blk_fetch_request"><link rel="next" href="API-blk-unprep-request.html" title="blk_unprep_request"></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">blk_update_request</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-blk-fetch-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-unprep-request.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-blk-update-request"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>blk_update_request &#8212; 
2     Special helper function for request stacking drivers
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">bool <b class="fsfunc">blk_update_request </b>(</code></td><td>struct request * <var class="pdparam">req</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">error</var>, </td></tr><tr><td>&#160;</td><td>unsigned int <var class="pdparam">nr_bytes</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1127998684"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>req</code></em></span></dt><dd><p>
4     the request being processed
5    </p></dd><dt><span class="term"><em class="parameter"><code>error</code></em></span></dt><dd><p>
6     <code class="constant">0</code> for success, &lt; <code class="constant">0</code> for error
7    </p></dd><dt><span class="term"><em class="parameter"><code>nr_bytes</code></em></span></dt><dd><p>
8     number of bytes to complete <em class="parameter"><code>req</code></em>
9    </p></dd></dl></div></div><div class="refsect1"><a name="idp1128003076"></a><h2>Description</h2><p>
10   Ends I/O on a number of bytes attached to <em class="parameter"><code>req</code></em>, but doesn't complete
11   the request structure even if <em class="parameter"><code>req</code></em> doesn't have leftover.
12   If <em class="parameter"><code>req</code></em> has leftover, sets it up for the next range of segments.
13   </p><p>
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15   This special helper function is only for request stacking drivers
16   (e.g. request-based dm) so that they can handle partial completion.
17   Actual device drivers should use blk_end_request instead.
18   </p><p>
19
20   Passing the result of <code class="function">blk_rq_bytes</code> as <em class="parameter"><code>nr_bytes</code></em> guarantees
21   <code class="constant">false</code> return from this function.
22</p></div><div class="refsect1"><a name="idp1128006372"></a><h2>Return</h2><p>
23   <code class="constant">false</code> - this request doesn't have any more data
24   <code class="constant">true</code>  - this request has more data
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