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>

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index a377ea36381e8dbbfe2f57b792bb9b4fad397aed..213f1bbeb82805caa42fc55d3204e5324452ae14 100644 (file)
--- 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,