linux-kernel - [PATCH v2] NFSv4.0: nfs4_do_fsinfo() should not do implicit lease

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Date:   Tue, 24 Dec 2019 14:36:31 -0000
From:   "Robert Milkowski" <rmilkowski@...il.com>
To:     <linux-nfs@...r.kernel.org>
Cc:     "'Trond Myklebust'" <trond.myklebust@...merspace.com>,
        "'Anna Schumaker'" <anna.schumaker@...app.com>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH v2] NFSv4.0: nfs4_do_fsinfo() should not do implicit lease

From: Robert Milkowski <rmilkowski@...il.com>

Currently, each time nfs4_do_fsinfo() is called it will do an implicit
NFS4 lease renewal, which is not compliant with the NFS4 specification.
This can result in a lease being expired by an NFS server.

Signed-off-by: Robert Milkowski <rmilkowski@...il.com>
---
 fs/nfs/nfs4proc.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 76d3716..b6cad9a 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5016,19 +5016,23 @@ static int _nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
 
 static int nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsinfo *fsinfo)
 {
+	struct nfs_client *clp = server->nfs_client;
 	struct nfs4_exception exception = {
 		.interruptible = true,
 	};
-	unsigned long now = jiffies;
+	unsigned long last_renewal = jiffies;
 	int err;
 
 	do {
 		err = _nfs4_do_fsinfo(server, fhandle, fsinfo);
 		trace_nfs4_fsinfo(server, fhandle, fsinfo->fattr, err);
 		if (err == 0) {
-			nfs4_set_lease_period(server->nfs_client,
+			/* no implicit lease renewal allowed here for v4.0 */
+			if (clp->cl_minorversion == 0 && clp->cl_last_renewal != 0)
+				last_renewal = clp->cl_last_renewal;
+			nfs4_set_lease_period(clp,
 					fsinfo->lease_time * HZ,
-					now);
+					last_renewal);
 			break;
 		}
 		err = nfs4_handle_exception(server, err, &exception);
-- 
1.8.3.1