[src/trunk]: src/sys/kern Redo Rev. 1.30: Change vfs_vnode_iterator_next() to...

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

details:   https://anonhg.NetBSD.org/src/rev/082784bd0ed8
branches:  trunk
changeset: 339988:082784bd0ed8
user:      hannken <hannken%NetBSD.org@localhost>
date:      Wed Aug 19 08:40:02 2015 +0000

description:
Redo Rev. 1.30: Change vfs_vnode_iterator_next() to skip reclaiming
vnodes (VI_XLOCK set) without waiting and change vflush() to wait for
these vnodes.

diffstat:

 sys/kern/vfs_mount.c |  35 ++++++++++++++++++++++++++++++-----
 1 files changed, 30 insertions(+), 5 deletions(-)

diffs (70 lines):

diff -r 4448c9b7cb47 -r 082784bd0ed8 sys/kern/vfs_mount.c
--- a/sys/kern/vfs_mount.c      Wed Aug 19 07:37:17 2015 +0000
+++ b/sys/kern/vfs_mount.c      Wed Aug 19 08:40:02 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_mount.c,v 1.36 2015/08/02 03:29:22 manu Exp $      */
+/*     $NetBSD: vfs_mount.c,v 1.37 2015/08/19 08:40:02 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 1.36 2015/08/02 03:29:22 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.37 2015/08/19 08:40:02 hannken Exp $");
 
 #define _VFS_VNODE_PRIVATE
 
@@ -394,7 +394,8 @@
                }
                mutex_enter(vp->v_interlock);
                if (ISSET(vp->v_iflag, VI_MARKER) ||
-                   (f && !ISSET(vp->v_iflag, VI_XLOCK) && !(*f)(cl, vp))) {
+                   ISSET(vp->v_iflag, VI_XLOCK) ||
+                   (f && !(*f)(cl, vp))) {
                        mutex_exit(vp->v_interlock);
                        vp = TAILQ_NEXT(vp, v_mntvnodes);
                        goto again;
@@ -507,7 +508,7 @@
 {
        vnode_t *vp;
        struct vnode_iterator *marker;
-       int busy = 0, when = 0;
+       int error, busy = 0, when = 0;
        struct vflush_ctx ctx;
 
        /* First, flush out any vnode references from vrele_list. */
@@ -540,7 +541,31 @@
        vfs_vnode_iterator_destroy(marker);
        if (busy)
                return (EBUSY);
-       return (0);
+
+       /* Wait for all vnodes to be reclaimed. */
+       for (;;) {
+               mutex_enter(&mntvnode_lock);
+               TAILQ_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) {
+                       if (vp == skipvp)
+                               continue;
+                       if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM))
+                               continue;
+                       break;
+               }
+               if (vp != NULL) {
+                       mutex_enter(vp->v_interlock);
+                       mutex_exit(&mntvnode_lock);
+                       error = vget(vp, 0, true /* wait */);
+                       if (error == ENOENT)
+                               continue;
+                       else if (error == 0)
+                               vrele(vp);
+                       return EBUSY;
+               } else {
+                       mutex_exit(&mntvnode_lock);
+                       return 0;
+               }
+       }
 }
 
 /*