1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>bdev_read_page</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="other_functions.html" title="Other Functions"><link rel="prev" href="API-thaw-bdev.html" title="thaw_bdev"><link rel="next" href="API-bdev-write-page.html" title="bdev_write_page"></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">bdev_read_page</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-thaw-bdev.html">Prev</a>&#160;</td><th width="60%" align="center">Other Functions</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-bdev-write-page.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-bdev-read-page"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>bdev_read_page &#8212; 
2     Start reading a page from a block device
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">int <b class="fsfunc">bdev_read_page </b>(</code></td><td>struct block_device * <var class="pdparam">bdev</var>, </td></tr><tr><td>&#160;</td><td>sector_t <var class="pdparam">sector</var>, </td></tr><tr><td>&#160;</td><td>struct page * <var class="pdparam">page</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1102852820"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>bdev</code></em></span></dt><dd><p>
4     The device to read the page from
5    </p></dd><dt><span class="term"><em class="parameter"><code>sector</code></em></span></dt><dd><p>
6     The offset on the device to read the page to (need not be aligned)
7    </p></dd><dt><span class="term"><em class="parameter"><code>page</code></em></span></dt><dd><p>
8     The page to read
9    </p></dd></dl></div></div><div class="refsect1"><a name="idp1102856532"></a><h2>Description</h2><p>
10   On entry, the page should be locked.  It will be unlocked when the page
11   has been read.  If the block driver implements rw_page synchronously,
12   that will be true on exit from this function, but it need not be.
13   </p><p>
14
15   Errors returned by this function are usually <span class="quote">&#8220;<span class="quote">soft</span>&#8221;</span>, eg out of memory, or
16   queue full; callers should try a different route to read this page rather
17   than propagate an error back up the stack.
18</p></div><div class="refsect1"><a name="idp1102857900"></a><h2>Return</h2><p>
19   negative errno if an error occurs, 0 if submission was successful.
20</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-thaw-bdev.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="other_functions.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-bdev-write-page.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">thaw_bdev</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">bdev_write_page</span></td></tr></table></div></body></html>
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