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>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 3feace66b981..6ea5c9392fe4 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -816,7 +816,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap, const
         if (iap->ia_valid & ATTR_MODE)
                 len += 4;
         if (iap->ia_valid & ATTR_UID) {
-                owner_namelen = nfs_map_uid_to_name(server->nfs_client, iap->ia_uid, owner_name);
+                owner_namelen = nfs_map_uid_to_name(server->nfs_client, iap->ia_uid, owner_name, IDMAP_NAMESZ);
                 if (owner_namelen < 0) {
                         dprintk("nfs: couldn't resolve uid %d to string\n",
                                         iap->ia_uid);
@@ -828,7 +828,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap, const
                 len += 4 + (XDR_QUADLEN(owner_namelen) << 2);
         }
         if (iap->ia_valid & ATTR_GID) {
-                owner_grouplen = nfs_map_gid_to_group(server->nfs_client, iap->ia_gid, owner_group);
+                owner_grouplen = nfs_map_gid_to_group(server->nfs_client, iap->ia_gid, owner_group, IDMAP_NAMESZ);
                 if (owner_grouplen < 0) {
                         dprintk("nfs: couldn't resolve gid %d to string\n",
                                         iap->ia_gid);