@BABOLO modify 2005-04-26 Original http://www.ambrisko.com/doug/ata/
--- sys/sys/proc.h
+++ sys/sys/proc.h
@@ -294,6 +294,8 @@
 #define	P_ALTSTACK	0x4000000 /* have alternate signal stack */
 #define	P_INEXEC	0x8000000 /* Process is in execve(). */
 
+#define P_SOFTDEP       0x10000000 /* Stuck processing softdep worklist */
+
 /*
  * MOVE TO ucred.h?
  *
--- sys/nfs/nfs_vnops.c
+++ sys/nfs/nfs_vnops.c
@@ -3004,6 +3004,8 @@
 	 */
 loop:
 	s = splbio();
+	/* DJA don't let soft update do more work */
+	p->p_flag |= P_SOFTDEP;
 	for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
 		nbp = TAILQ_NEXT(bp, b_vnbufs);
 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
@@ -3039,8 +3041,11 @@
 		    bp->b_flags |= B_ASYNC | B_WRITEINPROG;
 		splx(s);
 		VOP_BWRITE(bp->b_vp, bp);
+		/* DJA let someone else go */
+		tsleep(p, PZERO, "nfs_flush", hz);
 		goto loop;
 	}
+	p->p_flag &= ~P_SOFTDEP;
 	splx(s);
 	if (passone) {
 		passone = 0;
--- sys/ufs/ffs/ffs_softdep.c
+++ sys/ufs/ffs/ffs_softdep.c
@@ -4573,7 +4573,7 @@
 	/*
 	 * We never hold up the filesystem syncer process.
 	 */
-	if (p == filesys_syncer)
+	if (p == filesys_syncer || (p->p_flag & P_SOFTDEP))
 		return (0);
 	/*
 	 * First check to see if the work list has gotten backlogged.
@@ -4585,8 +4585,10 @@
 	if (num_on_worklist > max_softdeps / 10) {
 		if (islocked)
 			FREE_LOCK(&lk);
+		p->p_flag |= P_SOFTDEP;
 		process_worklist_item(NULL, LK_NOWAIT);
 		process_worklist_item(NULL, LK_NOWAIT);
+		p->p_flag &= ~P_SOFTDEP;
 		stat_worklist_push += 2;
 		if (islocked)
 			ACQUIRE_LOCK(&lk);