An NFSv4 server will reply NFSERR_GRACE for non-recovery RPCs

during the grace period after startup. This grace period must
be at least the lease duration, which is typically 1-2 minutes.
It seems prudent for the experimental NFS client to wait a few
seconds before retrying such an RPC, so that the server isn't
flooded with non-recovery RPCs during recovery. This patch adds
an argument to nfs_catnap() to implement a 5 second delay
for this case.

MFC after:	1 week

4 files changed, 13 insertions, 9 deletions

diff --git a/sys/fs/nfs/nfs_commonkrpc.c b/sys/fs/nfs/nfs_commonkrpc.c
index 8b6ada3865f3..384bdb417de1 100644
--- a/sys/fs/nfs/nfs_commonkrpc.c
+++ b/sys/fs/nfs/nfs_commonkrpc.c
@@ -650,7 +650,7 @@ tryagain:
 					trylater_delay = NFS_TRYLATERDEL;
 				waituntil = NFSD_MONOSEC + trylater_delay;
 				while (NFSD_MONOSEC < waituntil)
-					(void) nfs_catnap(PZERO, "nfstry");
+					(void) nfs_catnap(PZERO, 0, "nfstry");
 				trylater_delay *= 2;
 				goto tryagain;
 			}
diff --git a/sys/fs/nfs/nfs_commonport.c b/sys/fs/nfs/nfs_commonport.c
index 2849163837df..26765668d249 100644
--- a/sys/fs/nfs/nfs_commonport.c
+++ b/sys/fs/nfs/nfs_commonport.c
@@ -345,17 +345,21 @@ newnfs_timer(void *arg)
 
 
 /*
- * sleep for a short period of time.
+ * Sleep for a short period of time unless errval == NFSERR_GRACE, where
+ * the sleep should be for 5 seconds.
  * Since lbolt doesn't exist in FreeBSD-CURRENT, just use a timeout on
  * an event that never gets a wakeup. Only return EINTR or 0.
  */
 int
-nfs_catnap(int prio, const char *wmesg)
+nfs_catnap(int prio, int errval, const char *wmesg)
 {
 	static int non_event;
 	int ret;
 
-	ret = tsleep(&non_event, prio, wmesg, 1);
+	if (errval == NFSERR_GRACE)
+		ret = tsleep(&non_event, prio, wmesg, 5 * hz);
+	else
+		ret = tsleep(&non_event, prio, wmesg, 1);
 	if (ret != EINTR)
 		ret = 0;
 	return (ret);
diff --git a/sys/fs/nfs/nfs_var.h b/sys/fs/nfs/nfs_var.h
index 5388e13f5490..d6ecda217312 100644
--- a/sys/fs/nfs/nfs_var.h
+++ b/sys/fs/nfs/nfs_var.h
@@ -322,7 +322,7 @@ int nfsvno_v4rootexport(struct nfsrv_descript *);
 void newnfs_portinit(void);
 struct ucred *newnfs_getcred(void);
 void newnfs_setroot(struct ucred *);
-int nfs_catnap(int, const char *);
+int nfs_catnap(int, int, const char *);
 struct nfsreferral *nfsv4root_getreferral(vnode_t, vnode_t, u_int32_t);
 int nfsrv_atroot(vnode_t, long *);
 void newnfs_timer(void *);
diff --git a/sys/fs/nfs/nfsport.h b/sys/fs/nfs/nfsport.h
index 3d370040b443..0fa2e14602d3 100644
--- a/sys/fs/nfs/nfsport.h
+++ b/sys/fs/nfs/nfsport.h
@@ -143,21 +143,21 @@
 #define	NFSMGET(m)	do { 					\
 		MGET((m), M_TRYWAIT, MT_DATA); 			\
 		while ((m) == NULL ) { 				\
-			(void) nfs_catnap(PZERO, "nfsmget");	\
+			(void) nfs_catnap(PZERO, 0, "nfsmget");	\
 			MGET((m), M_TRYWAIT, MT_DATA); 		\
 		} 						\
 	} while (0)
 #define	NFSMGETHDR(m)	do { 					\
 		MGETHDR((m), M_TRYWAIT, MT_DATA);		\
 		while ((m) == NULL ) { 				\
-			(void) nfs_catnap(PZERO, "nfsmget");	\
+			(void) nfs_catnap(PZERO, 0, "nfsmget");	\
 			MGETHDR((m), M_TRYWAIT, MT_DATA); 	\
 		} 						\
 	} while (0)
 #define	NFSMCLGET(m, w)	do { 					\
 		MGET((m), M_TRYWAIT, MT_DATA); 			\
 		while ((m) == NULL ) { 				\
-			(void) nfs_catnap(PZERO, "nfsmget");	\
+			(void) nfs_catnap(PZERO, 0, "nfsmget");	\
 			MGET((m), M_TRYWAIT, MT_DATA); 		\
 		} 						\
 		MCLGET((m), (w));				\
@@ -165,7 +165,7 @@
 #define	NFSMCLGETHDR(m, w) do { 				\
 		MGETHDR((m), M_TRYWAIT, MT_DATA);		\
 		while ((m) == NULL ) { 				\
-			(void) nfs_catnap(PZERO, "nfsmget");	\
+			(void) nfs_catnap(PZERO, 0, "nfsmget");	\
 			MGETHDR((m), M_TRYWAIT, MT_DATA); 	\
 		} 						\
 	} while (0)