nfsd: Fix up nfsd to ensure that timeout errors don't result in ESTALE

If the underlying filesystem times out, then we want knfsd to return
NFSERR_JUKEBOX/DELAY rather than NFSERR_STALE.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfsfh.c

@@ -268,12 +268,20 @@ static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
 	if (fileid_type == FILEID_ROOT)
 		dentry = dget(exp->ex_path.dentry);
 	else {
-		dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
-				data_left, fileid_type,
-				nfsd_acceptable, exp);
-		if (IS_ERR_OR_NULL(dentry))
+		dentry = exportfs_decode_fh_raw(exp->ex_path.mnt, fid,
+						data_left, fileid_type,
+						nfsd_acceptable, exp);
+		if (IS_ERR_OR_NULL(dentry)) {
 			trace_nfsd_set_fh_dentry_badhandle(rqstp, fhp,
 					dentry ?  PTR_ERR(dentry) : -ESTALE);
+			switch (PTR_ERR(dentry)) {
+			case -ENOMEM:
+			case -ETIMEDOUT:
+				break;
+			default:
+				dentry = ERR_PTR(-ESTALE);
+			}
+		}
 	}
 	if (dentry == NULL)
 		goto out;