NFSv4.x: Fail client initialisation if state manager thread can't run

[ Upstream commit b4e4f66 ]

If the state manager thread fails to start, then we should just mark the
client initialisation as failed so that other processes or threads don't
get stuck in nfs_wait_client_init_complete().

Reported-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Fixes: 4697bd5 ("NFSv4: Fix a race in the net namespace mount notification")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/nfs/nfs4state.c

@@ -1230,6 +1230,8 @@ void nfs4_schedule_state_manager(struct nfs_client *clp)
 	if (IS_ERR(task)) {
 		printk(KERN_ERR "%s: kthread_run: %ld\n",
 			__func__, PTR_ERR(task));
+		if (!nfs_client_init_is_complete(clp))
+			nfs_mark_client_ready(clp, PTR_ERR(task));
 		nfs4_clear_state_manager_bit(clp);
 		clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
 		nfs_put_client(clp);