NFSv4: Send unmapped uid/gids to the server when using auth_sys

The new behaviour is enabled using the new module parameter
'nfs4_disable_idmapping'.

Note that if the server rejects an unmapped uid or gid, then
the client will automatically switch back to using the idmapper.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f4a04c0c7edc..14dcf1b7dd9c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1580,6 +1580,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         of returning the full 64-bit number.
                         The default is to return 64-bit inode numbers.
 
+        nfs.nfs4_disable_idmapping=
+                        [NFSv4] When set, this option disables the NFSv4
+                        idmapper on the client, but only if the mount
+                        is using the 'sec=sys' security flavour. This may
+                        make migration from legacy NFSv2/v3 systems easier
+                        provided that the server has the appropriate support.
+                        The default is to always enable NFSv4 idmapping.
+
         nmi_debug=      [KNL,AVR32,SH] Specify one or more actions to take
                         when a NMI is triggered.
                         Format: [state][,regs][,debounce][,die]