[src/trunk]: src/sys/kern Add file-local iterator variant vfs_vnode_iterator_...

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

details:   https://anonhg.NetBSD.org/src/rev/ff8db99e3b8c
branches:  trunk
changeset: 350525:ff8db99e3b8c
user:      hannken <hannken%NetBSD.org@localhost>
date:      Fri Jan 13 10:10:32 2017 +0000

description:
Add file-local iterator variant vfs_vnode_iterator_next1() that
waits for vnodes to become reclaimed and use it from vflush().

diffstat:

 sys/kern/vfs_mount.c |  55 ++++++++++++++++++---------------------------------
 1 files changed, 20 insertions(+), 35 deletions(-)

diffs (119 lines):

diff -r 33a996ab102c -r ff8db99e3b8c sys/kern/vfs_mount.c
--- a/sys/kern/vfs_mount.c      Fri Jan 13 08:41:46 2017 +0000
+++ b/sys/kern/vfs_mount.c      Fri Jan 13 10:10:32 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_mount.c,v 1.44 2017/01/11 09:07:57 hannken Exp $   */
+/*     $NetBSD: vfs_mount.c,v 1.45 2017/01/13 10:10:32 hannken Exp $   */
 
 /*-
  * Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.44 2017/01/11 09:07:57 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.45 2017/01/13 10:10:32 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -93,6 +93,9 @@
 #include <miscfs/genfs/genfs.h>
 #include <miscfs/specfs/specdev.h>
 
+static struct vnode *vfs_vnode_iterator_next1(struct vnode_iterator *,
+    bool (*)(void *, struct vnode *), void *, bool);
+
 /* Root filesystem. */
 vnode_t *                      rootvnode;
 
@@ -374,9 +377,9 @@
        vnfree_marker(mvp);
 }
 
-struct vnode *
-vfs_vnode_iterator_next(struct vnode_iterator *vni,
-    bool (*f)(void *, struct vnode *), void *cl)
+static struct vnode *
+vfs_vnode_iterator_next1(struct vnode_iterator *vni,
+    bool (*f)(void *, struct vnode *), void *cl, bool do_wait)
 {
        vnode_impl_t *mvip = &vni->vi_vnode;
        struct mount *mp = VIMPL_TO_VNODE(mvip)->v_mount;
@@ -399,7 +402,7 @@
                }
                mutex_enter(vp->v_interlock);
                if (vnis_marker(vp) ||
-                   vdead_check(vp, VDEAD_NOWAIT) ||
+                   vdead_check(vp, (do_wait ? 0 : VDEAD_NOWAIT)) ||
                    (f && !(*f)(cl, vp))) {
                        mutex_exit(vp->v_interlock);
                        vip = TAILQ_NEXT(vip, vi_mntvnodes);
@@ -416,6 +419,14 @@
        return vp;
 }
 
+struct vnode *
+vfs_vnode_iterator_next(struct vnode_iterator *vni,
+    bool (*f)(void *, struct vnode *), void *cl)
+{
+
+       return vfs_vnode_iterator_next1(vni, f, cl, false);
+}
+
 /*
  * Move a vnode from one mount queue to another.
  */
@@ -505,7 +516,7 @@
                yield();
                *when = hardclock_ticks + hz / 10;
        }
-       return vfs_vnode_iterator_next(marker, vflush_selector, ctx);
+       return vfs_vnode_iterator_next1(marker, vflush_selector, ctx, true);
 }
 
 
@@ -513,9 +524,8 @@
 vflush(struct mount *mp, vnode_t *skipvp, int flags)
 {
        vnode_t *vp;
-       vnode_impl_t *vip;
        struct vnode_iterator *marker;
-       int error, busy = 0, when = 0;
+       int busy = 0, when = 0;
        struct vflush_ctx ctx;
 
        /* First, flush out any vnode references from deferred vrele list. */
@@ -549,32 +559,7 @@
        if (busy)
                return (EBUSY);
 
-       /* Wait for all vnodes to be reclaimed. */
-       for (;;) {
-               mutex_enter(&mntvnode_lock);
-               TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
-                       vp = VIMPL_TO_VNODE(vip);
-                       if (vp == skipvp)
-                               continue;
-                       if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM))
-                               continue;
-                       break;
-               }
-               if (vip != NULL) {
-                       KASSERT(vp == VIMPL_TO_VNODE(vip));
-                       mutex_enter(vp->v_interlock);
-                       mutex_exit(&mntvnode_lock);
-                       error = vcache_vget(vp);
-                       if (error == ENOENT)
-                               continue;
-                       else if (error == 0)
-                               vrele(vp);
-                       return EBUSY;
-               } else {
-                       mutex_exit(&mntvnode_lock);
-                       return 0;
-               }
-       }
+       return 0;
 }
 
 /*