[src/trunk]: src/sys/fs/tmpfs tmpfs_alloc_vp:

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

details:   https://anonhg.NetBSD.org/src/rev/f5c5fcaf8e66
branches:  trunk
changeset: 765212:f5c5fcaf8e66
user:      rmind <rmind%NetBSD.org@localhost>
date:      Sun May 22 04:20:50 2011 +0000

description:
tmpfs_alloc_vp:
- Do not check for vn_lock(9) error, if LK_RETRY.
- Fix/improve comments.

diffstat:

 sys/fs/tmpfs/tmpfs_subr.c |  50 +++++++++++++++-------------------------------
 1 files changed, 17 insertions(+), 33 deletions(-)

diffs (93 lines):

diff -r 687fe43df2f9 -r f5c5fcaf8e66 sys/fs/tmpfs/tmpfs_subr.c
--- a/sys/fs/tmpfs/tmpfs_subr.c Sat May 21 20:05:02 2011 +0000
+++ b/sys/fs/tmpfs/tmpfs_subr.c Sun May 22 04:20:50 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tmpfs_subr.c,v 1.63 2011/04/01 17:40:54 hannken Exp $  */
+/*     $NetBSD: tmpfs_subr.c,v 1.64 2011/05/22 04:20:50 rmind Exp $    */
 
 /*
  * Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tmpfs_subr.c,v 1.63 2011/04/01 17:40:54 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tmpfs_subr.c,v 1.64 2011/05/22 04:20:50 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/dirent.h>
@@ -332,36 +332,28 @@
        tmpfs_dirent_put(tmp, de);
 }
 
-/* --------------------------------------------------------------------- */
-
 /*
- * Allocates a new vnode for the node node or returns a new reference to
- * an existing one if the node had already a vnode referencing it.  The
- * resulting locked vnode is returned in *vpp.
+ * tmpfs_alloc_vp: allocate or reclaim a vnode for a specified inode.
  *
- * Returns zero on success or an appropriate error code on failure.
+ * => Returns vnode (*vpp) locked.
  */
 int
 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, struct vnode **vpp)
 {
+       vnode_t *vp;
        int error;
-       struct vnode *vp;
-
-       /* If there is already a vnode, then lock it. */
-       for (;;) {
-               mutex_enter(&node->tn_vlock);
-               if ((vp = node->tn_vnode) != NULL) {
-                       mutex_enter(&vp->v_interlock);
-                       mutex_exit(&node->tn_vlock);
-                       error = vget(vp, LK_EXCLUSIVE);
-                       if (error == ENOENT) {
-                               /* vnode was reclaimed. */
-                               continue;
-                       }
-                       *vpp = vp;
-                       return error;
+again:
+       /* If there is already a vnode, try to reclaim it. */
+       mutex_enter(&node->tn_vlock);
+       if ((vp = node->tn_vnode) != NULL) {
+               mutex_enter(&vp->v_interlock);
+               mutex_exit(&node->tn_vlock);
+               error = vget(vp, LK_EXCLUSIVE);
+               if (error == ENOENT) {
+                       goto again;
                }
-               break;
+               *vpp = vp;
+               return error;
        }
 
        /* Get a new vnode and associate it with our node. */
@@ -371,13 +363,7 @@
                return error;
        }
 
-       error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
-       if (error != 0) {
-               mutex_exit(&node->tn_vlock);
-               ungetnewvnode(vp);
-               return error;
-       }
-
+       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
        vp->v_type = node->tn_type;
 
        /* Type-specific initialization. */
@@ -421,8 +407,6 @@
        return error;
 }
 
-/* --------------------------------------------------------------------- */
-
 /*
  * Destroys the association between the vnode vp and the node it
  * references.