NFSv4: Fix nfs_server_return_all_delegations

If the state manager thread is already running, we may end up
racing with it in nfs_client_return_marked_delegations. Better to
just allow the state manager thread to do the job.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 17 insertions, 7 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index a377ea36381e..213f1bbeb828 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -502,6 +502,18 @@ static void nfs_mark_return_delegation(struct nfs_server *server,
         set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
 }
 
+static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
+{
+        struct nfs_delegation *delegation;
+        bool ret = false;
+
+        list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+                nfs_mark_return_delegation(server, delegation);
+                ret = true;
+        }
+        return ret;
+}
+
 /**
  * nfs_super_return_all_delegations - return delegations for one superblock
  * @sb: sb to process
@@ -510,21 +522,19 @@ static void nfs_mark_return_delegation(struct nfs_server *server,
 void nfs_server_return_all_delegations(struct nfs_server *server)
 {
         struct nfs_client *clp = server->nfs_client;
-        struct nfs_delegation *delegation;
+        bool need_wait;
 
         if (clp == NULL)
                 return;
 
         rcu_read_lock();
-        list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
-                spin_lock(&delegation->lock);
-                set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
-                spin_unlock(&delegation->lock);
-        }
+        need_wait = nfs_server_mark_return_all_delegations(server);
         rcu_read_unlock();
 
-        if (nfs_client_return_marked_delegations(clp) != 0)
+        if (need_wait) {
                 nfs4_schedule_state_manager(clp);
+                nfs4_wait_clnt_recover(clp);
+        }
 }
 
 static void nfs_mark_return_all_delegation_types(struct nfs_server *server,