[src/trunk]: src/sys/fs/puffs Reinstante PNODE_DYING. vmlocking had a brief ...

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

details:   https://anonhg.NetBSD.org/src/rev/16da23622554
branches:  trunk
changeset: 748809:16da23622554
user:      pooka <pooka%NetBSD.org@localhost>
date:      Thu Nov 05 19:22:57 2009 +0000

description:
Reinstante PNODE_DYING.  vmlocking had a brief hiatus when it was not
a valid optimization, but that's long gone and once VOP_INACTIVE is
called and the file server says that the vnode is going to be recycled,
it really is going to be recycled extra references gained or not.

diffstat:

 sys/fs/puffs/puffs_sys.h   |   3 ++-
 sys/fs/puffs/puffs_vnops.c |  24 +++++++++++++++++++-----
 2 files changed, 21 insertions(+), 6 deletions(-)

diffs (83 lines):

diff -r 97906da8df48 -r 16da23622554 sys/fs/puffs/puffs_sys.h
--- a/sys/fs/puffs/puffs_sys.h  Thu Nov 05 18:39:38 2009 +0000
+++ b/sys/fs/puffs/puffs_sys.h  Thu Nov 05 19:22:57 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: puffs_sys.h,v 1.70 2008/01/28 21:06:37 pooka Exp $     */
+/*     $NetBSD: puffs_sys.h,v 1.71 2009/11/05 19:22:57 pooka Exp $     */
 
 /*
  * Copyright (c) 2005, 2006  Antti Kantee.  All Rights Reserved.
@@ -152,6 +152,7 @@
 
 
 #define PNODE_NOREFS   0x01    /* no backend reference                 */
+#define PNODE_DYING    0x02    /* NOREFS + inactive                    */
 #define PNODE_SUSPEND  0x04    /* issue all operations as FAF          */
 #define PNODE_DOINACT  0x08    /* if inactive-on-demand, call inactive */
 
diff -r 97906da8df48 -r 16da23622554 sys/fs/puffs/puffs_vnops.c
--- a/sys/fs/puffs/puffs_vnops.c        Thu Nov 05 18:39:38 2009 +0000
+++ b/sys/fs/puffs/puffs_vnops.c        Thu Nov 05 19:22:57 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: puffs_vnops.c,v 1.136 2009/10/17 23:16:05 pooka Exp $  */
+/*     $NetBSD: puffs_vnops.c,v 1.137 2009/11/05 19:22:57 pooka Exp $  */
 
 /*
  * Copyright (c) 2005, 2006, 2007  Antti Kantee.  All Rights Reserved.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: puffs_vnops.c,v 1.136 2009/10/17 23:16:05 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: puffs_vnops.c,v 1.137 2009/11/05 19:22:57 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/buf.h>
@@ -1028,7 +1028,10 @@
         * file server thinks it's gone?  then don't be afraid care,
         * node's life was already all it would ever be
         */
-       *ap->a_recycle = ((pnode->pn_stat & PNODE_NOREFS) != 0);
+       if (pnode->pn_stat & PNODE_NOREFS) {
+               pnode->pn_stat |= PNODE_DYING;
+               *ap->a_recycle = true;
+       }
 
        VOP_UNLOCK(vp, 0);
 
@@ -1295,7 +1298,8 @@
        pn = VPTOPP(vp);
 
        /* flush out information from our metacache, see vop_setattr */
-       if (pn->pn_stat & PNODE_METACACHE_MASK) {
+       if (pn->pn_stat & PNODE_METACACHE_MASK
+           && (pn->pn_stat & PNODE_DYING) == 0) {
                vattr_null(&va);
                error = VOP_SETATTR(vp, &va, FSCRED); 
                if (error)
@@ -1320,7 +1324,7 @@
         * has references neither in the kernel or the fs server.
         * Otherwise we continue to issue fsync() forward.
         */
-       if (!EXISTSOP(pmp, FSYNC))
+       if (!EXISTSOP(pmp, FSYNC) || (pn->pn_stat & PNODE_DYING))
                return 0;
 
        dofaf = (ap->a_flags & FSYNC_WAIT) == 0 || ap->a_flags == FSYNC_LAZY;
@@ -2168,6 +2172,16 @@
            || (BUF_ISWRITE(bp) && !EXISTSOP(pmp, WRITE)))
                ERROUT(EOPNOTSUPP);
 
+       /*
+        * Short-circuit optimization: don't flush buffer in between
+        * VOP_INACTIVE and VOP_RECLAIM in case the node has no references.
+        */
+       if (pn->pn_stat & PNODE_DYING) {
+               KASSERT(BUF_ISWRITE(bp));
+               bp->b_resid = 0;
+               goto out;
+       }
+
 #ifdef DIAGNOSTIC
        if (bp->b_bcount > pmp->pmp_msg_maxsize - PUFFS_MSGSTRUCT_MAX)
                panic("puffs_strategy: wildly inappropriate buf bcount %d",