From 996249571d0e8f9285d1b714b1c36d66e7649271 Mon Sep 17 00:00:00 2001
From: Ralph Wuerthner <ralph.wuerthner@de.ibm.com>
Date: Tue, 12 Jan 2016 16:00:24 +0100
Subject: vfs_fileid: add "fstype/mntdir deny/allow list" option

When using the fsname or fsid algorithm a stat() and statfs() call is
required for all mounted file systems to generate the file_id. If e.g.
an NFS file system is unresponsive such a call might block and the smbd
process will become unresponsive. Add "fileid:fstype deny",
"fileid:fstype allow", "fileid:mntdir deny", and "fileid:mntdir allow"
options to ignore potentially unresponsive file systems.

See also https://lists.samba.org/archive/samba-technical/2016-January/111553.html
for a discussion about why this is useful.

Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com>
Reviewed-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---
 docs-xml/manpages/vfs_fileid.8.xml | 47 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

(limited to 'docs-xml')

diff --git a/docs-xml/manpages/vfs_fileid.8.xml b/docs-xml/manpages/vfs_fileid.8.xml
index 5a3a70e9b95..568756ba519 100644
--- a/docs-xml/manpages/vfs_fileid.8.xml
+++ b/docs-xml/manpages/vfs_fileid.8.xml
@@ -40,6 +40,15 @@
 	generates the device number based on the configured algorithm
 	(see the "fileid:algorithm" option).
 	</para>
+
+	<para>When using the fsname or fsid algorithm a
+	<command>stat()</command> and <command>statfs()</command> call is
+	required for all mounted file systems to generate the file_id. If e.g.
+	an NFS file system is unresponsive such a call might block and the smbd
+	process will become unresponsive. Use the "fileid:fstype deny",
+	"fileid:fstype allow", "fileid:mntdir deny", or "fileid:mntdir allow"
+	options to ignore potentially unresponsive file systems.
+	</para>
 </refsect1>
 
 
@@ -75,6 +84,44 @@
 		</listitem>
 		</varlistentry>
 
+		<varlistentry>
+		<term>fileid:fstype deny = LIST</term>
+		<listitem>
+		<para>List of file system types to be ignored for file_id
+		generation.
+		</para>
+		</listitem>
+		</varlistentry>
+
+		<varlistentry>
+		<term>fileid:fstype allow = LIST</term>
+		<listitem>
+		<para>List of file system types to be allowed for file_id
+		generation. If this option is set, file system types not listed
+		here are ignored.
+		</para>
+		</listitem>
+		</varlistentry>
+
+		<varlistentry>
+		<term>fileid:mntdir deny = LIST</term>
+		<listitem>
+		<para>List of file system mount points to be ignored for
+		file_id	generation.
+		</para>
+		</listitem>
+		</varlistentry>
+
+		<varlistentry>
+		<term>fileid:mntdir allow = LIST</term>
+		<listitem>
+		<para>List of file system mount points to be allowed for file_id
+		generation. If this option is set, file system mount points
+		not listed here are ignored.
+		</para>
+		</listitem>
+		</varlistentry>
+
 	</variablelist>
 </refsect1>
 
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