NFS: new idmapper
This patch creates a new idmapper system that uses the request-key function to
place a call into userspace to map user and group ids to names. The old
idmapper was single threaded, which prevented more than one request from running
at a single time. This means that a user would have to wait for an upcall to
finish before accessing a cached result.
The upcall result is stored on a keyring of type id_resolver. See the file
Documentation/filesystems/nfs/idmapper.txt for instructions.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
[Trond: fix up the return value of nfs_idmap_lookup_name and clean up code]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 6c2aad4..3f69752 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -116,3 +116,14 @@
select DNS_RESOLVER
select KEYS
default y
+
+config NFS_USE_NEW_IDMAPPER
+ bool "Use the new idmapper upcall routine"
+ depends on NFS_V4 && KEYS
+ help
+ Say Y here if you want NFS to use the new idmapper upcall functions.
+ You will need /sbin/request-key (usually provided by the keyutils
+ package). For details, read
+ <file:Documentation/filesystems/nfs/idmapper.txt>.
+
+ If you are unsure, say N.