[src/trunk]: src/sys/kern For safety, cv_broadcast(&bp->b_busy) in more place...

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

details:   https://anonhg.NetBSD.org/src/rev/9fea92c342ef
branches:  trunk
changeset: 967430:9fea92c342ef
user:      ad <ad%NetBSD.org@localhost>
date:      Sun Dec 08 20:35:23 2019 +0000

description:
For safety, cv_broadcast(&bp->b_busy) in more places where the buffer is
changing identity or moving from one vnode list to another.

diffstat:

 sys/kern/vfs_bio.c |  11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diffs (46 lines):

diff -r e02ddd5a27a2 -r 9fea92c342ef sys/kern/vfs_bio.c
--- a/sys/kern/vfs_bio.c        Sun Dec 08 20:00:56 2019 +0000
+++ b/sys/kern/vfs_bio.c        Sun Dec 08 20:35:23 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_bio.c,v 1.281 2019/12/08 19:49:25 ad Exp $ */
+/*     $NetBSD: vfs_bio.c,v 1.282 2019/12/08 20:35:23 ad Exp $ */
 
 /*-
  * Copyright (c) 2007, 2008, 2009, 2019 The NetBSD Foundation, Inc.
@@ -123,7 +123,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.281 2019/12/08 19:49:25 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_bio.c,v 1.282 2019/12/08 20:35:23 ad Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_bufcache.h"
@@ -896,6 +896,8 @@
                mutex_enter(bp->b_objlock);
                CLR(bp->b_oflags, BO_DONE | BO_DELWRI);
                reassignbuf(bp, bp->b_vp);
+               /* Wake anyone trying to busy the buffer via vnode's lists. */
+               cv_broadcast(&bp->b_busy);
                mutex_exit(&bufcache_lock);
        } else {
                curlwp->l_ru.ru_oublock++;
@@ -988,6 +990,8 @@
                SET(bp->b_oflags, BO_DELWRI);
                curlwp->l_ru.ru_oublock++;
                reassignbuf(bp, bp->b_vp);
+               /* Wake anyone trying to busy the buffer via vnode's lists. */
+               cv_broadcast(&bp->b_busy);
                mutex_exit(&bufcache_lock);
        } else {
                mutex_enter(bp->b_objlock);
@@ -1411,6 +1415,9 @@
 
                /* Buffer is no longer on free lists. */
                SET(bp->b_cflags, BC_BUSY);
+
+               /* Wake anyone trying to lock the old identity. */
+               cv_broadcast(&bp->b_busy);
        } else {
                /*
                 * XXX: !from_bufq should be removed.