MFC r313735: add svcpool_close to handle killed nfsd threads

PR:		204340
Reported by:	Panzura
Reviewed by:	rmacklem
Approved by:	rmacklem

3 files changed, 55 insertions, 13 deletions

diff --git a/sys/fs/nfsserver/nfs_nfsdkrpc.c b/sys/fs/nfsserver/nfs_nfsdkrpc.c
index 0b2333f..5c47447 100644
--- a/sys/fs/nfsserver/nfs_nfsdkrpc.c
+++ b/sys/fs/nfsserver/nfs_nfsdkrpc.c
@@ -554,18 +554,16 @@ nfsrvd_init(int terminating)
 		nfsd_master_proc = NULL;
 		NFSD_UNLOCK();
 		nfsrv_freeallbackchannel_xprts();
-		svcpool_destroy(nfsrvd_pool);
-		nfsrvd_pool = NULL;
+		svcpool_close(nfsrvd_pool);
+		NFSD_LOCK();
+	} else {
+		NFSD_UNLOCK();
+		nfsrvd_pool = svcpool_create("nfsd",
+		    SYSCTL_STATIC_CHILDREN(_vfs_nfsd));
+		nfsrvd_pool->sp_rcache = NULL;
+		nfsrvd_pool->sp_assign = fhanew_assign;
+		nfsrvd_pool->sp_done = fha_nd_complete;
 		NFSD_LOCK();
 	}
-
-	NFSD_UNLOCK();
-
-	nfsrvd_pool = svcpool_create("nfsd", SYSCTL_STATIC_CHILDREN(_vfs_nfsd));
-	nfsrvd_pool->sp_rcache = NULL;
-	nfsrvd_pool->sp_assign = fhanew_assign;
-	nfsrvd_pool->sp_done = fha_nd_complete;
-
-	NFSD_LOCK();
 }
 
diff --git a/sys/rpc/svc.c b/sys/rpc/svc.c
index ff25ee4..c6a70ea 100644
--- a/sys/rpc/svc.c
+++ b/sys/rpc/svc.c
@@ -75,6 +75,7 @@ static void svc_new_thread(SVCGROUP *grp);
 static void xprt_unregister_locked(SVCXPRT *xprt);
 static void svc_change_space_used(SVCPOOL *pool, long delta);
 static bool_t svc_request_space_available(SVCPOOL *pool);
+static void svcpool_cleanup(SVCPOOL *pool);
 
 /* ***************  SVCXPRT related stuff **************** */
 
@@ -174,8 +175,12 @@ svcpool_create(const char *name, struct sysctl_oid_list *sysctl_base)
 	return pool;
 }
 
-void
-svcpool_destroy(SVCPOOL *pool)
+/*
+ * Code common to svcpool_destroy() and svcpool_close(), which cleans up
+ * the pool data structures.
+ */
+static void
+svcpool_cleanup(SVCPOOL *pool)
 {
 	SVCGROUP *grp;
 	SVCXPRT *xprt, *nxprt;
@@ -211,6 +216,15 @@ svcpool_destroy(SVCPOOL *pool)
 		mtx_lock(&pool->sp_lock);
 	}
 	mtx_unlock(&pool->sp_lock);
+}
+
+void
+svcpool_destroy(SVCPOOL *pool)
+{
+	SVCGROUP *grp;
+	int g;
+
+	svcpool_cleanup(pool);
 
 	for (g = 0; g < SVC_MAXGROUPS; g++) {
 		grp = &pool->sp_groups[g];
@@ -226,6 +240,30 @@ svcpool_destroy(SVCPOOL *pool)
 }
 
 /*
+ * Similar to svcpool_destroy(), except that it does not destroy the actual
+ * data structures.  As such, "pool" may be used again.
+ */
+void
+svcpool_close(SVCPOOL *pool)
+{
+	SVCGROUP *grp;
+	int g;
+
+	svcpool_cleanup(pool);
+
+	/* Now, initialize the pool's state for a fresh svc_run() call. */
+	mtx_lock(&pool->sp_lock);
+	pool->sp_state = SVCPOOL_INIT;
+	mtx_unlock(&pool->sp_lock);
+	for (g = 0; g < SVC_MAXGROUPS; g++) {
+		grp = &pool->sp_groups[g];
+		mtx_lock(&grp->sg_lock);
+		grp->sg_state = SVCPOOL_ACTIVE;
+		mtx_unlock(&grp->sg_lock);
+	}
+}
+
+/*
  * Sysctl handler to get the present thread count on a pool
  */
 static int
diff --git a/sys/rpc/svc.h b/sys/rpc/svc.h
index 80285ec..2ecd1a9 100644
--- a/sys/rpc/svc.h
+++ b/sys/rpc/svc.h
@@ -729,6 +729,12 @@ extern SVCPOOL* svcpool_create(const char *name,
 extern void svcpool_destroy(SVCPOOL *pool);
 
 /*
+ * Close a service pool.  Similar to svcpool_destroy(), but it does not
+ * free the data structures.  As such, the pool can be used again.
+ */
+extern void svcpool_close(SVCPOOL *pool);
+
+/*
  * Transport independent svc_create routine.
  */
 extern int svc_create(SVCPOOL *, void (*)(struct svc_req *, SVCXPRT *),