SUNRPC: Fix "EPIPE" error on mount of rpcsec_gss-protected partitions

 gss_create_upcall() should not error just because rpc.gssd closed the
 pipe on its end. Instead, it should requeue the pending requests and then
 retry.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/auth_gss/auth_gss.c

@@ -638,7 +638,7 @@ gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 				gss_msg);
 		atomic_inc(&gss_msg->count);
 		gss_unhash_msg(gss_msg);
-		if (msg->errno == -ETIMEDOUT || msg->errno == -EPIPE) {
+		if (msg->errno == -ETIMEDOUT) {
 			unsigned long now = jiffies;
 			if (time_after(now, ratelimit)) {
 				printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
@@ -786,7 +786,9 @@ gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
 	cred->gc_flags = 0;
 	cred->gc_base.cr_ops = &gss_credops;
 	cred->gc_service = gss_auth->service;
-	err = gss_create_upcall(gss_auth, cred);
+	do {
+		err = gss_create_upcall(gss_auth, cred);
+	} while (err == -EAGAIN);
 	if (err < 0)
 		goto out_err;
 

net/sunrpc/rpc_pipe.c

@@ -174,7 +174,7 @@ rpc_pipe_release(struct inode *inode, struct file *filp)
 		goto out;
 	msg = (struct rpc_pipe_msg *)filp->private_data;
 	if (msg != NULL) {
-		msg->errno = -EPIPE;
+		msg->errno = -EAGAIN;
 		list_del_init(&msg->list);
 		rpci->ops->destroy_msg(msg);
 	}
@@ -183,7 +183,7 @@ rpc_pipe_release(struct inode *inode, struct file *filp)
 	if (filp->f_mode & FMODE_READ)
 		rpci->nreaders --;
 	if (!rpci->nreaders)
-		__rpc_purge_upcall(inode, -EPIPE);
+		__rpc_purge_upcall(inode, -EAGAIN);
 	if (rpci->ops->release_pipe)
 		rpci->ops->release_pipe(inode);
 out: