nfs: handle servers that support only ALLOW ACE type.

Currently we support ACLs if the NFS server file system supports both
ALLOW and DENY ACE types. This patch makes the Linux client work with
ACLs even if the server supports only 'ALLOW' ACE type.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Author: malahal

fs/nfs/nfs4proc.c

@@ -2744,7 +2744,8 @@ static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *f
 				NFS_CAP_OWNER_GROUP|NFS_CAP_ATIME|
 				NFS_CAP_CTIME|NFS_CAP_MTIME|
 				NFS_CAP_SECURITY_LABEL);
-		if (res.attr_bitmask[0] & FATTR4_WORD0_ACL)
+		if (res.attr_bitmask[0] & FATTR4_WORD0_ACL &&
+				res.acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
 			server->caps |= NFS_CAP_ACLS;
 		if (res.has_links != 0)
 			server->caps |= NFS_CAP_HARDLINKS;
@@ -4321,9 +4322,7 @@ static int nfs4_proc_renew(struct nfs_client *clp, struct rpc_cred *cred)
 
 static inline int nfs4_server_supports_acls(struct nfs_server *server)
 {
-	return (server->caps & NFS_CAP_ACLS)
-		&& (server->acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
-		&& (server->acl_bitmask & ACL4_SUPPORT_DENY_ACL);
+	return server->caps & NFS_CAP_ACLS;
 }
 
 /* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_SIZE, and that