[src/trunk]: src/sys/nfs nfs_request: fix races which break congestion window...

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bbd49a6e16b5
branches:  trunk
changeset: 750935:bbd49a6e16b5
user:      yamt <yamt%NetBSD.org@localhost>
date:      Tue Jan 19 13:39:04 2010 +0000

description:
nfs_request: fix races which break congestion window and make nfs client stuck.

diffstat:

 sys/nfs/nfs_socket.c |  14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diffs (51 lines):

diff -r 9f67b8910756 -r bbd49a6e16b5 sys/nfs/nfs_socket.c
--- a/sys/nfs/nfs_socket.c      Tue Jan 19 13:29:40 2010 +0000
+++ b/sys/nfs/nfs_socket.c      Tue Jan 19 13:39:04 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nfs_socket.c,v 1.184 2009/12/31 19:31:31 christos Exp $        */
+/*     $NetBSD: nfs_socket.c,v 1.185 2010/01/19 13:39:04 yamt Exp $    */
 
 /*
  * Copyright (c) 1989, 1991, 1993, 1995
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_socket.c,v 1.184 2009/12/31 19:31:31 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_socket.c,v 1.185 2010/01/19 13:39:04 yamt Exp $");
 
 #ifdef _KERNEL_OPT
 #include "fs_nfs.h"
@@ -1133,10 +1133,14 @@
                        if (nmp->nm_soflags & PR_CONNREQUIRED)
                                nfs_sndunlock(nmp);
                }
+               s = splsoftnet();
                if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
-                       nmp->nm_sent += NFS_CWNDSCALE;
-                       rep->r_flags |= R_SENT;
+                       if ((rep->r_flags & R_SENT) == 0) {
+                               nmp->nm_sent += NFS_CWNDSCALE;
+                               rep->r_flags |= R_SENT;
+                       }
                }
+               splx(s);
        } else {
                splx(s);
                rep->r_rtt = -1;
@@ -1153,7 +1157,6 @@
         */
        s = splsoftnet();
        TAILQ_REMOVE(&nfs_reqq, rep, r_chain);
-       splx(s);
 
        /*
         * Decrement the outstanding request count.
@@ -1162,6 +1165,7 @@
                rep->r_flags &= ~R_SENT;        /* paranoia */
                nmp->nm_sent -= NFS_CWNDSCALE;
        }
+       splx(s);
 
        if (rexmitp != NULL) {
                int rexmit;