The branch, master has been updated
via 1ca4df5 Use sys_pread/sys_pwrite to cope correctly with 64-bit
sizes. As in the default VFS case fall back from pread -> read and pwrite ->
write on an ESPIPE error in the worker thread.
via d8c6991 Add man page for vfs_aio_pthread module.
from 851b2c1 s3: Fix a panic in aio_pthread
http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit 1ca4df58c76e98d963d90c092532ca584606ccff
Author: Jeremy Allison <j...@samba.org>
Date: Wed Jan 25 15:30:56 2012 -0800
Use sys_pread/sys_pwrite to cope correctly with 64-bit sizes. As in the
default VFS case fall back from pread -> read and pwrite -> write on an ESPIPE
error in the worker thread.
Autobuild-User: Jeremy Allison <j...@samba.org>
Autobuild-Date: Thu Jan 26 02:11:28 CET 2012 on sn-devel-104
commit d8c699190d2cc0ce64395c7b2b10bb25c98a2943
Author: Jeremy Allison <j...@samba.org>
Date: Wed Jan 25 14:11:12 2012 -0800
Add man page for vfs_aio_pthread module.
-----------------------------------------------------------------------
Summary of changes:
docs-xml/manpages-3/vfs_aio_pthread.8.xml | 118 +++++++++++++++++++++++++++++
source3/modules/vfs_aio_pthread.c | 18 ++++-
2 files changed, 134 insertions(+), 2 deletions(-)
create mode 100644 docs-xml/manpages-3/vfs_aio_pthread.8.xml
Changeset truncated at 500 lines:
diff --git a/docs-xml/manpages-3/vfs_aio_pthread.8.xml
b/docs-xml/manpages-3/vfs_aio_pthread.8.xml
new file mode 100644
index 0000000..625d6f3
--- /dev/null
+++ b/docs-xml/manpages-3/vfs_aio_pthread.8.xml
@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant
V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc";>
+<refentry id="vfs_aio_pthread.8">
+
+<refmeta>
+ <refentrytitle>vfs_aio_pthread</refentrytitle>
+ <manvolnum>8</manvolnum>
+ <refmiscinfo class="source">Samba</refmiscinfo>
+ <refmiscinfo class="manual">System Administration tools</refmiscinfo>
+ <refmiscinfo class="version">3.6</refmiscinfo>
+</refmeta>
+
+
+<refnamediv>
+ <refname>vfs_aio_pthread</refname>
+ <refpurpose>implement async I/O in Samba vfs using a pthread
pool</refpurpose>
+</refnamediv>
+
+<refsynopsisdiv>
+ <cmdsynopsis>
+ <command>vfs objects = aio_pthread</command>
+ </cmdsynopsis>
+</refsynopsisdiv>
+
+<refsect1>
+ <title>DESCRIPTION</title>
+
+ <para>This VFS module is part of the
+ <citerefentry><refentrytitle>samba</refentrytitle>
+ <manvolnum>7</manvolnum></citerefentry> suite.</para>
+
+ <para>The <command>aio_pthread</command> VFS module enables asynchronous
+ I/O for Samba on platforms which have the pthreads API available,
+ without using the Posix AIO interface. Posix AIO can suffer from severe
+ limitations. For example, on some Linux versions the
+ real-time signals that it uses are broken under heavy load.
+ Other systems only allow AIO when special kernel modules are
+ loaded or only allow a certain system-wide amount of async
+ requests being scheduled. Systems based on glibc (most Linux
+ systems) only allow a single outstanding request per file
+ descriptor which essentially makes Posix AIO useless on systems
+ using the glibc implementation.</para>
+
+ <para>To work around all these limitations, the aio_pthread module
+ was written. It uses a pthread pool instead of the
+ internal Posix AIO interface to allow read and write calls
+ to be process asynchronously. A pthread pool is created
+ which expands dynamically by creating new threads as work is
+ given to it to a maximum of 100 threads per smbd process.
+ To change this limit see the "aio num threads" parameter
+ below. New threads are not created if idle threads are
+ available when a new read or write request is received,
+ the new work is given to an existing idle thread. Threads
+ terminate themselves if idle for one second.
+ </para>
+
+ <para>
+ Note that the smb.conf parameters <command>aio read size</command>
+ and <command>aio write size</command> must also be set appropriately
+ for this module to be active.
+ </para>
+
+ <para>This module MUST be listed last in any module stack as
+ the Samba VFS pread/pwrite interface is not thread-safe. This
+ module makes direct pread and pwrite system calls and does
+ NOT call the Samba VFS pread and pwrite interfaces.</para>
+
+</refsect1>
+
+
+<refsect1>
+ <title>EXAMPLES</title>
+
+ <para>Straight forward use:</para>
+
+<programlisting>
+ <smbconfsection name="[cooldata]"/>
+ <smbconfoption name="path">/data/ice</smbconfoption>
+ <smbconfoption name="vfs objects">aio_fork</smbconfoption>
+</programlisting>
+
+</refsect1>
+
+<refsect1>
+ <title>OPTIONS</title>
+
+ <variablelist>
+
+ <varlistentry>
+ <term>aio_pthread:aio num threads = INTEGER</term>
+ <listitem>
+ <para>Limit the maximum number of threads per smbd that
+ will be created in the thread pool to service IO requests.
+ </para>
+ <para>By default this is set to 100.</para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+</refsect1>
+<refsect1>
+ <title>VERSION</title>
+
+ <para>This man page is correct for version 3.6.3 of the Samba suite.
+ </para>
+</refsect1>
+
+<refsect1>
+ <title>AUTHOR</title>
+
+ <para>The original Samba software and related utilities
+ were created by Andrew Tridgell. Samba is now developed
+ by the Samba Team as an Open Source project similar
+ to the way the Linux kernel is developed.</para>
+
+</refsect1>
+
+</refentry>
diff --git a/source3/modules/vfs_aio_pthread.c
b/source3/modules/vfs_aio_pthread.c
index e1cc492..c172ff0 100644
--- a/source3/modules/vfs_aio_pthread.c
+++ b/source3/modules/vfs_aio_pthread.c
@@ -115,15 +115,29 @@ static void aio_worker(void *private_data)
(struct aio_private_data *)private_data;
if (pd->write_command) {
- pd->ret_size = pwrite(pd->aiocb->aio_fildes,
+ pd->ret_size = sys_pwrite(pd->aiocb->aio_fildes,
(const void *)pd->aiocb->aio_buf,
pd->aiocb->aio_nbytes,
pd->aiocb->aio_offset);
+ if (pd->ret_size == -1 && errno == ESPIPE) {
+ /* Maintain the fiction that pipes can
+ be seeked (sought?) on. */
+ pd->ret_size = sys_write(pd->aiocb->aio_fildes,
+ (const void *)pd->aiocb->aio_buf,
+ pd->aiocb->aio_nbytes);
+ }
} else {
- pd->ret_size = pread(pd->aiocb->aio_fildes,
+ pd->ret_size = sys_pread(pd->aiocb->aio_fildes,
(void *)pd->aiocb->aio_buf,
pd->aiocb->aio_nbytes,
pd->aiocb->aio_offset);
+ if (pd->ret_size == -1 && errno == ESPIPE) {
+ /* Maintain the fiction that pipes can
+ be seeked (sought?) on. */
+ pd->ret_size = sys_read(pd->aiocb->aio_fildes,
+ (void *)pd->aiocb->aio_buf,
+ pd->aiocb->aio_nbytes);
+ }
}
if (pd->ret_size == -1) {
pd->ret_errno = errno;
--
Samba Shared Repository
