docs-xml/manpages: Add warning about write-behind translator for vfs_glusterfs

Add warning about data corruption with the write-behind translator.

The data corruption is highlighted by the smbtorture test smb2.rw.rw1.
More information about this data corruption issue is available in the
bz.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14486

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>
(cherry picked from commit 08f8f665d409ee7b93840c25a8142f2ce8bacfa1)

diff --git a/docs-xml/manpages/vfs_glusterfs.8.xml b/docs-xml/manpages/vfs_glusterfs.8.xml
index cf3b8e5e3842a10e0b2cb372468579a44067a16d..7a4da1af9199f19606c02ec75af59eb06561c729 100644 (file)
--- a/docs-xml/manpages/vfs_glusterfs.8.xml
+++ b/docs-xml/manpages/vfs_glusterfs.8.xml
@@ -161,6 +161,28 @@
 
 </refsect1>
 
+<refsect1>
+       <title>CAVEATS</title>
+
+       <para>
+                The GlusterFS write-behind performance translator, when used
+                with Samba, could be a source of data corruption. The
+                translator, while processing a write call, immediately returns
+                success but continues writing the data to the server in the
+                background. This can cause data corruption when two clients
+                relying on Samba to provide data consistency are operating on
+                the same file.
+        </para>
+        <para>
+                The write-behind translator is enabled by default on GlusterFS.
+                The vfs_glusterfs plugin will check for the presence of the
+                translator and refuse to connect if detected.
+                Please disable the write-behind translator for the GlusterFS
+                volume to allow the plugin to connect to the volume.
+       </para>
+</refsect1>
+
+
 <refsect1>
        <title>VERSION</title>