s3:param: Add new option "strict rename".

Control whether smbd can rename directories containing
open files. Defaults to "no" (meaning we *can* do
such renames).

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

docs-xml/smbdotconf/tuning/strictrename.xml

@@ -0,0 +1,25 @@
+<samba:parameter name="strict rename"
+                 context="S"
+				 type="boolean"
+                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
+<description>
+    <para>By default a Windows SMB server prevents directory
+    renames when there are open file or directory handles below
+    it in the filesystem hierarchy. Historically Samba has always
+    allowed this as POSIX filesystem semantics require it.</para>
+
+    <para>This boolean parameter allows Samba to match the Windows
+    behavior. Setting this to "yes" is a very expensive change,
+    as it forces Samba to travers the entire open file handle
+    database on every directory rename request. In a clustered
+    Samba system the cost is even greater than the non-clustered
+    case.</para>
+
+    <para>For this reason the default is "no", and it is recommended
+    to be left that way unless a specific Windows application requires
+    it to be changed.</para>
+
+</description>
+
+<value type="default">no</value>
+</samba:parameter>

lib/param/param_table.c

@@ -1883,6 +1883,15 @@ struct parm_struct parm_table[] = {
 		.enum_list	= NULL,
 		.flags		= FLAG_ADVANCED | FLAG_SHARE,
 	},
+	{
+		.label		= "strict rename",
+		.type		= P_BOOL,
+		.p_class	= P_LOCAL,
+		.offset		= LOCAL_VAR(strict_rename),
+		.special	= NULL,
+		.enum_list	= NULL,
+		.flags		= FLAG_ADVANCED | FLAG_SHARE,
+	},
 	{
 		.label		= "strict sync",
 		.type		= P_BOOL,

source3/param/loadparm.c

@@ -206,6 +206,7 @@ static struct loadparm_service sDefault =
 	.follow_symlinks = true,
 	.sync_always = false,
 	.strict_allocate = false,
+	.strict_rename = false,
 	.strict_sync = false,
 	.mangling_char = '~',
 	.copymap = NULL,