svn commit: r336928 - stable/10/sys/rpc

[Rick Macklem]

Author: rmacklem
Date: Mon Jul 30 19:29:31 2018
New Revision: 336928
URL: https://svnweb.freebsd.org/changeset/base/336928

Log:
  MFC: r335866
  Fix the server side krpc so that the kernel nfsd threads terminate.
  
  Occationally the kernel nfsd threads would not terminate when a SIGKILL
  was posted for the kernel process (called nfsd (slave)). When this occurred,
  the thread associated with the process (called "ismaster") had returned from
  svc_run_internal() and was sleeping waiting for the other threads to terminate.
  The other threads (created by kthread_start()) were still in svc_run_internal()
  handling NFS RPCs.
  The only way this could occur is for the "ismaster" thread to return from
  svc_run_internal() without having called svc_exit().
  There was only one place in the code where this could happen and this patch
  stops that from happening.
  Since the problem is intermittent, I cannot be sure if this has fixed the
  problem, but I have not seen an occurrence of the problem with this patch
  applied.

Modified:
  stable/10/sys/rpc/svc.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/rpc/svc.c
==============================================================================
--- stable/10/sys/rpc/svc.c	Mon Jul 30 19:23:52 2018	(r336927)
+++ stable/10/sys/rpc/svc.c	Mon Jul 30 19:29:31 2018	(r336928)
@@ -1183,7 +1183,8 @@ svc_run_internal(SVCGROUP *grp, bool_t ismaster)
 			/*
 			 * Enforce maxthreads count.
 			 */
-			if (grp->sg_threadcount > grp->sg_maxthreads)
+			if (!ismaster && grp->sg_threadcount >
+			    grp->sg_maxthreads)
 				break;
 
 			/*