NFS: Allow NFSROOT debugging messages to be enabled dynamically

As a convenience, introduce a kernel command line option to enable
NFSROOT debugging messages.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 26 insertions, 1 deletions

diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt
index f2430a7974e1..90c71c6f0d00 100644
--- a/Documentation/filesystems/nfs/nfsroot.txt
+++ b/Documentation/filesystems/nfs/nfsroot.txt
@@ -159,6 +159,28 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>
                 Default: any
 
 
+nfsrootdebug
+
+  This parameter enables debugging messages to appear in the kernel
+  log at boot time so that administrators can verify that the correct
+  NFS mount options, server address, and root path are passed to the
+  NFS client.
+
+
+rdinit=<executable file>
+
+  To specify which file contains the program that starts system
+  initialization, administrators can use this command line parameter.
+  The default value of this parameter is "/init".  If the specified
+  file exists and the kernel can execute it, root filesystem related
+  kernel command line parameters, including `nfsroot=', are ignored.
+
+  A description of the process of mounting the root file system can be
+  found in:
+
+    Documentation/early-userspace/README
+
+
 
 
 3.) Boot Loader
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f084af0cb8e0..0fe70b2c4194 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1532,12 +1532,15 @@ and is between 256 and 4096 characters. It is defined in the file
                         1 to enable accounting
                         Default value is 0.
 
-        nfsaddrs=       [NFS]
+        nfsaddrs=       [NFS] Deprecated.  Use ip= instead.
                         See Documentation/filesystems/nfs/nfsroot.txt.
 
         nfsroot=        [NFS] nfs root filesystem for disk-less boxes.
                         See Documentation/filesystems/nfs/nfsroot.txt.
 
+        nfsrootdebug    [NFS] enable nfsroot debugging messages.
+                        See Documentation/filesystems/nfs/nfsroot.txt.
+
         nfs.callback_tcpport=
                         [NFS] set the TCP port on which the NFSv4 callback
                         channel should listen.