[src/trunk]: src/sys/fs/smbfs smbfs_node_alloc():

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

details:   https://anonhg.NetBSD.org/src/rev/997972f4a6b2
branches:  trunk
changeset: 543407:997972f4a6b2
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Mon Feb 24 15:55:08 2003 +0000

description:
smbfs_node_alloc():
* use LK_RETRY for the vget()
* turn the check for dead parent vnode to #ifdef DIAGNOSTIC panic
* reformat the hash walk code a little, and only assign vp if entries match
* add some comments

diffstat:

 sys/fs/smbfs/smbfs_node.c |  24 +++++++++++++++---------
 1 files changed, 15 insertions(+), 9 deletions(-)

diffs (64 lines):

diff -r 7a61a47e6f39 -r 997972f4a6b2 sys/fs/smbfs/smbfs_node.c
--- a/sys/fs/smbfs/smbfs_node.c Mon Feb 24 15:14:51 2003 +0000
+++ b/sys/fs/smbfs/smbfs_node.c Mon Feb 24 15:55:08 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: smbfs_node.c,v 1.8 2003/02/23 21:55:20 jdolecek Exp $  */
+/*     $NetBSD: smbfs_node.c,v 1.9 2003/02/24 15:55:08 jdolecek Exp $  */
 
 /*
  * Copyright (c) 2000-2001 Boris Popov
@@ -152,26 +152,27 @@
                if (dvp == NULL)
                        return EINVAL;
                vp = VTOSMB(dvp)->n_parent->n_vnode;
-               if ((error = vget(vp, LK_EXCLUSIVE)) == 0)
+               if ((error = vget(vp, LK_EXCLUSIVE | LK_RETRY)) == 0)
                        *vpp = vp;
                return (error);
        }
 
        dnp = dvp ? VTOSMB(dvp) : NULL;
-       if (dnp == NULL && dvp != NULL) {
-               vprint("smbfs_node_alloc: dead parent vnode", dvp);
-               return EINVAL;
-       }
+#ifdef DIAGNOSTIC
+       if (dnp == NULL && dvp != NULL)
+               panic("smbfs_node_alloc: dead parent vnode %p", dvp);
+#endif
        hashval = smbfs_hash(name, nmlen);
 retry:
        smbfs_hash_lock(smp);
 loop:
        nhpp = SMBFS_NOHASH(smp, hashval);
        LIST_FOREACH(np, nhpp, n_hash) {
+               if (np->n_parent != dnp
+                   || np->n_nmlen != nmlen
+                   || memcmp(name, np->n_name, nmlen) != 0)
+                       continue;
                vp = SMBTOV(np);
-               if (np->n_parent != dnp ||
-                   np->n_nmlen != nmlen || memcmp(name, np->n_name, nmlen) != 0)
-                       continue;
                simple_lock(&(vp)->v_interlock);
                smbfs_hash_unlock(smp);
                if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0)
@@ -219,6 +220,10 @@
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 
        smbfs_hash_lock(smp);
+       /*
+        * Check if the vnode wasn't added while we were in getnewvnode/
+        * malloc.
+        */
        LIST_FOREACH(np2, nhpp, n_hash) {
                if (np2->n_parent != dnp
                    || np2->n_nmlen != nmlen
@@ -228,6 +233,7 @@
                goto loop;
        }
 
+       /* Not on hash list, add it now */
        LIST_INSERT_HEAD(nhpp, np, n_hash);
        smbfs_hash_unlock(smp);