The following reply was made to PR kern/33406; it has been noted by GNATS.

From: Simon Burge <simonb@wasabisystems.com>
To: gnats-bugs@netbsd.org
Cc: kern-bug-people@netbsd.org, gnats-admin@netbsd.org,
	netbsd-bugs@netbsd.org
Subject: Re: kern/33406: softdeps get stuck in endless loop 
Date: Tue, 02 May 2006 00:52:09 +1000

 With the following patches running on an i386 with a 115200 baud serial
 console, I can reproduce this problem using the lat_fs recipe in the PR.
 
 The Debugger call in vfs_subr.c drops you to ddb after a while.  You
 may need to "c"ontinue a couple of times before you see the problem.  I
 added the Debugger check since sending a BREAK to the serial console
 didn't drop in to ddb while the console was busying sending so much
 output.
 
 
 Index: kern/vfs_bio.c
 ===================================================================
 RCS file: /cvsroot/src/sys/kern/vfs_bio.c,v
 retrieving revision 1.159
 diff -d -p -u -r1.159 vfs_bio.c
 --- kern/vfs_bio.c	5 Apr 2006 00:52:16 -0000	1.159
 +++ kern/vfs_bio.c	1 May 2006 14:06:31 -0000
 @@ -735,7 +735,10 @@ bwrite(struct buf *bp)
  	 * vnode queue.
  	 */
  	if (wasdelayed)
 +{
 +printf("bwrite: reassignbuf\n");
  		reassignbuf(bp, bp->b_vp);
 +}
  	else
  		p->p_stats->p_ru.ru_oublock++;
  
 Index: kern/vfs_subr.c
 ===================================================================
 RCS file: /cvsroot/src/sys/kern/vfs_subr.c,v
 retrieving revision 1.265
 diff -d -p -u -r1.265 vfs_subr.c
 --- kern/vfs_subr.c	25 Feb 2006 07:11:31 -0000	1.265
 +++ kern/vfs_subr.c	1 May 2006 14:06:32 -0000
 @@ -862,6 +862,9 @@ vflushbuf(struct vnode *vp, int sync)
  loop:
  	s = splbio();
  	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
 +static int loops = 0;
 +if (loops++ % 1000 == 0)
 + Debugger();
  		nbp = LIST_NEXT(bp, b_vnbufs);
  		simple_lock(&bp->b_interlock);
  		if ((bp->b_flags & B_BUSY)) {
 Index: ufs/ffs/ffs_softdep.c
 ===================================================================
 RCS file: /cvsroot/src/sys/ufs/ffs/ffs_softdep.c,v
 retrieving revision 1.73
 diff -d -p -u -r1.73 ffs_softdep.c
 --- ufs/ffs/ffs_softdep.c	24 Dec 2005 20:45:10 -0000	1.73
 +++ ufs/ffs/ffs_softdep.c	1 May 2006 14:06:33 -0000
 @@ -4032,6 +4032,7 @@ softdep_disk_write_complete(bp)
  	/*
  	 * Reattach any requests that must be redone.
  	 */
 +printf("reattach loop\n");
  	while ((wk = LIST_FIRST(&reattach)) != NULL) {
  		WORKLIST_REMOVE(wk);
  		WORKLIST_INSERT(&bp->b_dep, wk);