From 3137e0cee14197a13af3538c472a1374311bf16b Mon Sep 17 00:00:00 2001
From: hannken <hannken@NetBSD.org>
Date: Wed, 12 Apr 2017 10:26:33 +0000
Subject: [PATCH] Switch vfs_vnode_lock_print() and printlockedvnodes() to
 _mountlist_next().

Switch sched_sync() and sysctl_kern_vnode() to mountlist iterator.
---
 sys/kern/vfs_subr.c | 47 ++++++++++++++++-----------------------------
 1 file changed, 17 insertions(+), 30 deletions(-)

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 71bf3234d37a..fbad14036079 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: vfs_subr.c,v 1.461 2017/03/31 08:38:14 msaitoh Exp $	*/
+/*	$NetBSD: vfs_subr.c,v 1.462 2017/04/12 10:26:33 hannken Exp $	*/
 
 /*-
  * Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.461 2017/03/31 08:38:14 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.462 2017/04/12 10:26:33 hannken Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -759,9 +759,10 @@ lazy_sync_vnode(struct vnode *vp)
 void
 sched_sync(void *arg)
 {
+	mount_iterator_t *iter;
 	synclist_t *slp;
 	struct vnode *vp;
-	struct mount *mp, *nmp;
+	struct mount *mp;
 	time_t starttime;
 	bool synced;
 
@@ -773,23 +774,19 @@ sched_sync(void *arg)
 		/*
 		 * Sync mounts whose dirty time has expired.
 		 */
-		mutex_enter(&mountlist_lock);
-		for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
+		mountlist_iterator_init(&iter);
+		while ((mp = mountlist_iterator_next(iter)) != NULL) {
 			if ((mp->mnt_iflag & IMNT_ONWORKLIST) == 0 ||
 			    mp->mnt_synclist_slot != syncer_delayno) {
-				nmp = TAILQ_NEXT(mp, mnt_list);
 				continue;
 			}
 			mp->mnt_synclist_slot = sync_delay_slot(sync_delay(mp));
-			if (vfs_busy(mp, &nmp))
-				continue;
 			if (fstrans_start_nowait(mp, FSTRANS_SHARED) == 0) {
 				VFS_SYNC(mp, MNT_LAZY, curlwp->l_cred);
 				fstrans_done(mp);
 			}
-			vfs_unbusy(mp, false, &nmp);
 		}
-		mutex_exit(&mountlist_lock);
+		mountlist_iterator_destroy(iter);
 
 		mutex_enter(&syncer_data_lock);
 
@@ -967,8 +964,9 @@ sysctl_kern_vnode(SYSCTLFN_ARGS)
 {
 	char *where = oldp;
 	size_t *sizep = oldlenp;
-	struct mount *mp, *nmp;
+	struct mount *mp;
 	vnode_t *vp, vbuf;
+	mount_iterator_t *iter;
 	struct vnode_iterator *marker;
 	char *bp = where;
 	char *ewhere;
@@ -988,17 +986,14 @@ sysctl_kern_vnode(SYSCTLFN_ARGS)
 	ewhere = where + *sizep;
 
 	sysctl_unlock();
-	mutex_enter(&mountlist_lock);
-	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
-		if (vfs_busy(mp, &nmp)) {
-			continue;
-		}
+	mountlist_iterator_init(&iter);
+	while ((mp = mountlist_iterator_next(iter)) != NULL) {
 		vfs_vnode_iterator_init(mp, &marker);
 		while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL))) {
 			if (bp + VPTRSZ + VNODESZ > ewhere) {
 				vrele(vp);
 				vfs_vnode_iterator_destroy(marker);
-				vfs_unbusy(mp, false, NULL);
+				mountlist_iterator_destroy(iter);
 				sysctl_relock();
 				*sizep = bp - where;
 				return (ENOMEM);
@@ -1008,7 +1003,7 @@ sysctl_kern_vnode(SYSCTLFN_ARGS)
 			    (error = copyout(&vbuf, bp + VPTRSZ, VNODESZ))) {
 				vrele(vp);
 				vfs_vnode_iterator_destroy(marker);
-				vfs_unbusy(mp, false, NULL);
+				mountlist_iterator_destroy(iter);
 				sysctl_relock();
 				return (error);
 			}
@@ -1016,9 +1011,8 @@ sysctl_kern_vnode(SYSCTLFN_ARGS)
 			bp += VPTRSZ + VNODESZ;
 		}
 		vfs_vnode_iterator_destroy(marker);
-		vfs_unbusy(mp, false, &nmp);
 	}
-	mutex_exit(&mountlist_lock);
+	mountlist_iterator_destroy(iter);
 	sysctl_relock();
 
 	*sizep = bp - where;
@@ -1549,7 +1543,7 @@ vfs_vnode_lock_print(void *vlock, int full, void (*pr)(const char *, ...))
 	struct mount *mp;
 	vnode_impl_t *vip;
 
-	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
+	for (mp = _mountlist_next(NULL); mp; mp = _mountlist_next(mp)) {
 		TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
 			if (&vip->vi_lock != vlock)
 				continue;
@@ -1656,25 +1650,18 @@ void printlockedvnodes(void);
 void
 printlockedvnodes(void)
 {
-	struct mount *mp, *nmp;
+	struct mount *mp;
 	vnode_t *vp;
 	vnode_impl_t *vip;
 
 	printf("Locked vnodes\n");
-	mutex_enter(&mountlist_lock);
-	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
-		if (vfs_busy(mp, &nmp)) {
-			continue;
-		}
+	for (mp = _mountlist_next(NULL); mp; mp = _mountlist_next(mp)) {
 		TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
 			vp = VIMPL_TO_VNODE(vip);
 			if (VOP_ISLOCKED(vp))
 				vprint(NULL, vp);
 		}
-		mutex_enter(&mountlist_lock);
-		vfs_unbusy(mp, false, &nmp);
 	}
-	mutex_exit(&mountlist_lock);
 }
 
 #endif /* DDB || DEBUGPRINT */