[src/ad-namecache]: src/sys/kern vcache_reclaim(): purge namecache immediatel...

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

details:   https://anonhg.NetBSD.org/src/rev/94f42ae0e489
branches:  ad-namecache
changeset: 850544:94f42ae0e489
user:      ad <ad%NetBSD.org@localhost>
date:      Thu Jan 23 19:28:39 2020 +0000

description:
vcache_reclaim(): purge namecache immediately after setting vnode to
VS_RECLAIMED.

diffstat:

 sys/kern/vfs_vnode.c |  14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diffs (42 lines):

diff -r 453bdf94af48 -r 94f42ae0e489 sys/kern/vfs_vnode.c
--- a/sys/kern/vfs_vnode.c      Thu Jan 23 12:33:18 2020 +0000
+++ b/sys/kern/vfs_vnode.c      Thu Jan 23 19:28:39 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_vnode.c,v 1.105.2.3 2020/01/17 21:55:13 ad Exp $   */
+/*     $NetBSD: vfs_vnode.c,v 1.105.2.4 2020/01/23 19:28:39 ad Exp $   */
 
 /*-
  * Copyright (c) 1997-2011, 2019 The NetBSD Foundation, Inc.
@@ -145,7 +145,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.105.2.3 2020/01/17 21:55:13 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.105.2.4 2020/01/23 19:28:39 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -1582,6 +1582,13 @@
        vp->v_iflag &= ~(VI_TEXT|VI_EXECMAP);
        mutex_exit(vp->v_interlock);
 
+       /*
+        * With vnode state set to reclaiming, purge name cache immediately
+        * to prevent new handles on vnode, and wait for existing threads
+        * trying to get a handle to notice VS_RECLAIMED status and abort.
+        */
+       cache_purge(vp);
+
        /* Replace the vnode key with a temporary copy. */
        if (vip->vi_key.vk_key_len > sizeof(temp_buf)) {
                temp_key = kmem_alloc(temp_key_len, KM_SLEEP);
@@ -1635,9 +1642,6 @@
                vp->v_ractx = NULL;
        }
 
-       /* Purge name cache. */
-       cache_purge(vp);
-
        if (vip->vi_key.vk_key_len > 0) {
        /* Remove from vnode cache. */
                hash = vcache_hash(&vip->vi_key);