[src/trunk]: src/sys/fs/sysvbfs fix refcounting

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

details:   https://anonhg.NetBSD.org/src/rev/b2a47dcf7a33
branches:  trunk
changeset: 755185:b2a47dcf7a33
user:      pooka <pooka%NetBSD.org@localhost>
date:      Wed May 26 21:27:00 2010 +0000

description:
fix refcounting

diffstat:

 sys/fs/sysvbfs/sysvbfs_vnops.c |  23 +++++++++++++++--------
 1 files changed, 15 insertions(+), 8 deletions(-)

diffs (60 lines):

diff -r afeec6754032 -r b2a47dcf7a33 sys/fs/sysvbfs/sysvbfs_vnops.c
--- a/sys/fs/sysvbfs/sysvbfs_vnops.c    Wed May 26 18:07:34 2010 +0000
+++ b/sys/fs/sysvbfs/sysvbfs_vnops.c    Wed May 26 21:27:00 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sysvbfs_vnops.c,v 1.27 2010/05/26 17:52:35 pooka Exp $ */
+/*     $NetBSD: sysvbfs_vnops.c,v 1.28 2010/05/26 21:27:00 pooka Exp $ */
 
 /*-
  * Copyright (c) 2004 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sysvbfs_vnops.c,v 1.27 2010/05/26 17:52:35 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sysvbfs_vnops.c,v 1.28 2010/05/26 21:27:00 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -493,7 +493,9 @@
                struct componentname *a_tcnp;
        } */ *ap = arg;
        struct vnode *fvp = ap->a_fvp;
+       struct vnode *fdvp = ap->a_fdvp;
        struct vnode *tvp = ap->a_tvp;
+       struct vnode *tdvp = ap->a_tdvp;
        struct sysvbfs_node *bnode = fvp->v_data;
        struct bfs *bfs = bnode->bmp->bfs;
        const char *from_name = ap->a_fcnp->cn_nameptr;
@@ -501,7 +503,7 @@
        int error;
 
        DPRINTF("%s: %s->%s\n", __func__, from_name, to_name);
-       if ((fvp->v_mount != ap->a_tdvp->v_mount) ||
+       if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount))) {
                error = EXDEV;
                printf("cross-device link\n");
@@ -513,12 +515,17 @@
 
        error = bfs_file_rename(bfs, from_name, to_name);
  out:
-       vput(ap->a_tdvp);
        if (tvp)
-               vput(ap->a_tvp);  /* locked on entry */
-       if (ap->a_tdvp != ap->a_fdvp)
-               vrele(ap->a_fdvp);
-       vrele(ap->a_fvp); /* unlocked and refcnt is incremented on entry. */
+               vput(tvp);
+
+       /* tdvp == tvp probably can't happen with this fs, but safety first */
+       if (tdvp == tvp)
+               vrele(tdvp);
+       else
+               vput(tdvp);
+
+       vrele(fdvp);
+       vrele(fvp);
 
        return 0;
 }