commit a602bea3e7ccc5ce3da61d2c18245c4058983926 Author: Bryan Schumaker Date: Thu Jan 26 16:54:25 2012 -0500 NFS: Update idmapper documentation Signed-off-by: Bryan Schumaker Signed-off-by: Trond Myklebust diff -up linux-3.2.noarch/Documentation/filesystems/nfs/idmapper.txt.orig linux-3.2.noarch/Documentation/filesystems/nfs/idmapper.txt --- linux-3.2.noarch/Documentation/filesystems/nfs/idmapper.txt.orig 2012-01-04 18:55:44.000000000 -0500 +++ linux-3.2.noarch/Documentation/filesystems/nfs/idmapper.txt 2012-01-27 10:19:55.406740364 -0500 @@ -4,13 +4,21 @@ ID Mapper ========= Id mapper is used by NFS to translate user and group ids into names, and to translate user and group names into ids. Part of this translation involves -performing an upcall to userspace to request the information. Id mapper will -user request-key to perform this upcall and cache the result. The program -/usr/sbin/nfs.idmap should be called by request-key, and will perform the -translation and initialize a key with the resulting information. +performing an upcall to userspace to request the information. There are two +ways NFS could obtain this information: placing a call to /sbin/request-key +or by placing a call to the rpc.idmap daemon. + +NFS will attempt to call /sbin/request-key first. If this succeeds, the +result will be cached using the generic request-key cache. This call should +only fail if /etc/request-key.conf is not configured for the id_resolver key +type, see the "Configuring" section below if you wish to use the request-key +method. + +If the call to /sbin/request-key fails (if /etc/request-key.conf is not +configured with the id_resolver key type), then the idmapper will ask the +legacy rpc.idmap daemon for the id mapping. This result will be stored +in a custom NFS idmap cache. - NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to use this - feature. =========== Configuring