NFS over TCP retransmit behavior should default to a 60 second time out,

mimicing the NFS reference implementation.

NFS over TCP does not need fast retransmit timeouts, since network loss
and congestion are managed by the transport (TCP), unlike with NFS over
UDP.  A long timeout prevents the unnecessary retransmission of non-
idempotent NFS requests.

Reviewed by:	mohans, silby, rees?
Sponsored by:	Network Appliance, Incorporated

3 files changed, 17 insertions, 5 deletions

diff --git a/sys/nfs4client/nfs4_vfsops.c b/sys/nfs4client/nfs4_vfsops.c
index d4fc2d6..0eb113b 100644
--- a/sys/nfs4client/nfs4_vfsops.c
+++ b/sys/nfs4client/nfs4_vfsops.c
@@ -245,12 +245,18 @@ nfs_decode_args(struct nfsmount *nmp, struct nfs_args *argp)
 	int maxio;
 
 	s = splnet();
+
 	/*
 	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
-	 * no sense in that context.
+	 * no sense in that context.  Also, set appropriate retransmit
+	 * and soft timeout behavior.
 	 */
-	if (argp->sotype == SOCK_STREAM)
+	if (argp->sotype == SOCK_STREAM) {
 		nmp->nm_flag &= ~NFSMNT_NOCONN;
+		nmp->nm_flag |= NFSMNT_DUMBTIMR;
+		nmp->nm_timeo = NFS_MAXTIMEO;
+		nmp->nm_retry = NFS_RETRANS_TCP;
+	}
 
 	nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
 
diff --git a/sys/nfsclient/nfs.h b/sys/nfsclient/nfs.h
index 9dc34a7..a87966d 100644
--- a/sys/nfsclient/nfs.h
+++ b/sys/nfsclient/nfs.h
@@ -53,7 +53,8 @@
 #define	NFS_MAXTIMEO	(60 * NFS_HZ)	/* Max timeout to backoff to */
 #define	NFS_MINIDEMTIMEO (5 * NFS_HZ)	/* Min timeout for non-idempotent ops*/
 #define	NFS_MAXREXMIT	100		/* Stop counting after this many */
-#define	NFS_RETRANS	10		/* Num of retrans for soft mounts */
+#define	NFS_RETRANS	10		/* Num of retrans for UDP soft mounts */
+#define	NFS_RETRANS_TCP	2		/* Num of retrans for TCP soft mounts */
 #define	NFS_MAXGRPS	16		/* Max. size of groups list */
 #ifndef NFS_MINATTRTIMO
 #define	NFS_MINATTRTIMO 3		/* VREG attrib cache timeout in sec */
diff --git a/sys/nfsclient/nfs_vfsops.c b/sys/nfsclient/nfs_vfsops.c
index 17a009c..858f405 100644
--- a/sys/nfsclient/nfs_vfsops.c
+++ b/sys/nfsclient/nfs_vfsops.c
@@ -545,10 +545,15 @@ nfs_decode_args(struct mount *mp, struct nfsmount *nmp, struct nfs_args *argp)
 
 	/*
 	 * Silently clear NFSMNT_NOCONN if it's a TCP mount, it makes
-	 * no sense in that context.
+	 * no sense in that context.  Also, set up appropriate retransmit
+	 * and soft timeout behavior.
 	 */
-	if (argp->sotype == SOCK_STREAM)
+	if (argp->sotype == SOCK_STREAM) {
 		nmp->nm_flag &= ~NFSMNT_NOCONN;
+		nmp->nm_flag |= NFSMNT_DUMBTIMR;
+		nmp->nm_timeo = NFS_MAXTIMEO;
+		nmp->nm_retry = NFS_RETRANS_TCP;
+	}
 
 	/* Also clear RDIRPLUS if not NFSv3, it crashes some servers */
 	if ((argp->flags & NFSMNT_NFSV3) == 0)