svn commit: r286559 - stable/9/sbin/umount

[Rick Macklem]

Author: rmacklem
Date: Sun Aug  9 22:29:10 2015
New Revision: 286559
URL: https://svnweb.freebsd.org/changeset/base/286559

Log:
  MFC: r284531
  Document that a forced dismount of an NFSv3 mount when the
  NLM (rpc.lockd) is running can crash the system.
  Unfortunately this is not easy to fix, but I have left
  PR#200585 open.

Modified:
  stable/9/sbin/umount/umount.8
Directory Properties:
  stable/9/sbin/umount/   (props changed)

Modified: stable/9/sbin/umount/umount.8
==============================================================================
--- stable/9/sbin/umount/umount.8	Sun Aug  9 22:07:52 2015	(r286558)
+++ stable/9/sbin/umount/umount.8	Sun Aug  9 22:29:10 2015	(r286559)
@@ -28,7 +28,7 @@
 .\"     @(#)umount.8	8.2 (Berkeley) 5/8/95
 .\" $FreeBSD$
 .\"
-.Dd May 31, 2011
+.Dd June 17, 2015
 .Dt UMOUNT 8
 .Os
 .Sh NAME
@@ -81,6 +81,9 @@ The root file system cannot be forcibly 
 For NFS, a forced dismount can take up to 1 minute or more to
 complete against an unresponsive server and may throw away
 data not yet written to the server for this case.
+Also, doing a forced dismount of an NFSv3 mount when
+.Xr rpc.lockd 8
+is running is unsafe and can result in a crash.
 .It Fl h Ar host
 Only file systems mounted from the specified host will be
 unmounted.