Mon Sep 28 00:39:03 2009 UTC ()

Avoid nasal demons. Code of the form

   vput(vp);
   error = VFS_VGET(vp->v_mount, ...);

just isn't right. Because of vnode caching this *probably* never bit
anyone, except maybe under very heavy load, but still.


(dholland)

diff -r1.101 -r1.102 src/sys/ufs/ufs/ufs_lookup.c

--- src/sys/ufs/ufs/ufs_lookup.c 2009/02/22 20:28:07	1.101
+++ src/sys/ufs/ufs/ufs_lookup.c 2009/09/28 00:39:03	1.102

 @@ -1,14 +1,14 @@
-/*	$NetBSD: ufs_lookup.c,v 1.101 2009/02/22 20:28:07 ad Exp $	*/
+/*	$NetBSD: ufs_lookup.c,v 1.102 2009/09/28 00:39:03 dholland Exp $	*/
 /*
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
  * (c) UNIX System Laboratories, Inc.
  * All or some portions of this file are derived from material licensed
  * to the University of California by American Telephone and Telegraph
  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  * the permission of UNIX System Laboratories, Inc.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
 @@ -27,27 +27,27 @@
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
  *	@(#)ufs_lookup.c	8.9 (Berkeley) 8/11/94
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ufs_lookup.c,v 1.101 2009/02/22 20:28:07 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ufs_lookup.c,v 1.102 2009/09/28 00:39:03 dholland Exp $");
 #ifdef _KERNEL_OPT
 #include "opt_ffs.h"
 #include "fs_ffs.h"
 #endif
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/namei.h>
 #include <sys/buf.h>
 #include <sys/file.h>
 #include <sys/stat.h>
 #include <sys/mount.h>
 @@ -1166,27 +1166,27 @@ ufs_dirempty(struct inode *ip, ino_t par
 		return (0);
+	}
 	return (1);
+}
 /*
  * Check if source directory is in the path of the target directory.
  * Target is supplied locked, source is unlocked.
  * The target is always vput before returning.
  */
 int
 ufs_checkpath(struct inode *source, struct inode *target, kauth_cred_t cred)
+{
-	struct vnode *vp = ITOV(target);
+	struct vnode *nextvp, *vp;
 	int error, rootino, namlen;
 	struct dirtemplate dirbuf;
 	const int needswap = UFS_MPNEEDSWAP(target->i_ump);
 	vp = ITOV(target);
 	if (target->i_number == source->i_number) {
 		error = EEXIST;
 		goto out;
+	}
 	rootino = ROOTINO;
 	error = 0;
 	if (target->i_number == rootino)
 		goto out;
 @@ -1214,33 +1214,35 @@ ufs_checkpath(struct inode *source, stru
 #endif
 		if (namlen != 2 ||
 		    dirbuf.dotdot_name[0] != '.' ||
 		    dirbuf.dotdot_name[1] != '.') {
 			error = ENOTDIR;
 			break;
+		}
 		if (ufs_rw32(dirbuf.dotdot_ino, needswap) == source->i_number) {
 			error = EINVAL;
 			break;
+		}
 		if (ufs_rw32(dirbuf.dotdot_ino, needswap) == rootino)
 			break;
-		vput(vp);
+		VOP_UNLOCK(vp, 0);
 		error = VFS_VGET(vp->v_mount,
-		    ufs_rw32(dirbuf.dotdot_ino, needswap), &vp);
+		    ufs_rw32(dirbuf.dotdot_ino, needswap), &nextvp);
 		vrele(vp);
 		if (error) {
 			vp = NULL;
 			break;
+		}
 		vp = nextvp;
+	}
 out:
 	if (error == ENOTDIR)
 		printf("checkpath: .. not a directory\n");
 	if (vp != NULL)
 		vput(vp);
 	return (error);
+}
 #define	UFS_DIRRABLKS 0
 int ufs_dirrablks = UFS_DIRRABLKS;