[PATCH 6/7] NFSv4.1: Deal with server reboots during delegation expiration recovery

[Trond Myklebust <trond.myklebust@primarydata.com>]

Ensure that if the server reboots while we're testing and recovering
from revoked delegations, we exit to allow the state manager to
handle matters.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/nfs/delegation.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index ff0c1a0feb9d..b873271c613a 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -874,6 +874,13 @@ restart:
 	rcu_read_unlock();
 }
 
+static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
+{
+	return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
+				BIT(NFS4CLNT_LEASE_EXPIRED) |
+				BIT(NFS4CLNT_SESSION_RESET))) != 0;
+}
+
 static void nfs_mark_test_expired_delegation(struct nfs_server *server,
 	    struct nfs_delegation *delegation)
 {
@@ -882,6 +889,19 @@ static void nfs_mark_test_expired_delegation(struct nfs_server *server,
 	set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
 }
 
+static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
+		struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (delegation)
+		nfs_mark_test_expired_delegation(server, delegation);
+	rcu_read_unlock();
+
+}
+
 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
 {
 	struct nfs_delegation *delegation;
@@ -954,6 +974,12 @@ restart:
 				nfs_inode_find_state_and_recover(inode, &stateid);
 			}
 			put_rpccred(cred);
+			if (nfs4_server_rebooted(clp)) {
+				nfs_inode_mark_test_expired_delegation(server,inode);
+				iput(inode);
+				nfs_sb_deactive(server->super);
+				return;
+			}
 			iput(inode);
 			nfs_sb_deactive(server->super);
 			goto restart;
-- 
2.7.4