docs-xml: rewrite the vfs_aio_pthread manpage to reflect the >= 4.0.0 behavior

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

1 files changed, 14 insertions, 37 deletions

diff --git a/docs-xml/manpages/vfs_aio_pthread.8.xml b/docs-xml/manpages/vfs_aio_pthread.8.xml
index 69a83468bff..c6f291b980e 100644
--- a/docs-xml/manpages/vfs_aio_pthread.8.xml
+++ b/docs-xml/manpages/vfs_aio_pthread.8.xml
@@ -13,7 +13,7 @@
 
 <refnamediv>
 	<refname>vfs_aio_pthread</refname>
-	<refpurpose>implement async I/O in Samba vfs using a pthread pool</refpurpose>
+	<refpurpose>implement async open in Samba vfs using a pthread pool</refpurpose>
 </refnamediv>
 
 <refsynopsisdiv>
@@ -30,40 +30,18 @@
 	<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.
+	opens (for new files) with <smbconfoption name="aio_pthread:aio open">yes</smbconfoption>
+	on platforms which have the pthreads API available,
+	support the openat() syscall and support per thread credentials (modern Linux kernels).
 	</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>The module makes use of the global thread pool which uses the
+	<smbconfoption name="aio max threads"/> option.</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>
+	the Samba VFS open interface is not thread-safe. This
+	module makes direct openat() system calls and does
+	NOT call the Samba VFS open interfaces.</para>
 
 </refsect1>
 
@@ -76,9 +54,8 @@
 <programlisting>
         <smbconfsection name="[cooldata]"/>
 	<smbconfoption name="path">/data/ice</smbconfoption>
-	<smbconfoption name="aio read size">1024</smbconfoption>
-	<smbconfoption name="aio write size">1024</smbconfoption>
 	<smbconfoption name="vfs objects">aio_pthread</smbconfoption>
+	<smbconfoption name="aio_pthread:aio open">yes</smbconfoption>
 </programlisting>
 
 </refsect1>
@@ -89,17 +66,17 @@
 	<variablelist>
 
 		<varlistentry>
-		<term>aio_pthread:aio num threads = INTEGER</term>
+		<term>aio_pthread:aio open = BOOL</term>
 		<listitem>
-		<para>Limit the maximum number of threads per smbd that
-		will be created in the thread pool to service IO requests.
+		<para>Try async opens for creating new files.
 		</para>
-		<para>By default this is set to 100.</para>
+		<para>The default is 'no'.</para>
 		</listitem>
 		</varlistentry>
 
 	</variablelist>
 </refsect1>
+
 <refsect1>
 	<title>VERSION</title>