770 lines
20 KiB
C
770 lines
20 KiB
C
/* $Id: msdosfs_lookup.c,v 1.1 1994/09/19 15:41:44 dfr Exp $ */
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/* $NetBSD: msdosfs_lookup.c,v 1.14 1994/08/21 18:44:07 ws Exp $ */
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/*-
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* Copyright (C) 1994 Wolfgang Solfrank.
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* Copyright (C) 1994 TooLs GmbH.
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* All rights reserved.
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* Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by TooLs GmbH.
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* 4. The name of TooLs GmbH may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Written by Paul Popelka (paulp@uts.amdahl.com)
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*
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* You can do anything you want with this software, just don't say you wrote
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* it, and don't remove this notice.
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*
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* This software is provided "as is".
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*
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* The author supplies this software to be publicly redistributed on the
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* understanding that the author is not responsible for the correct
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* functioning of this software in any circumstances and is not liable for
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* any damages caused by this software.
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*
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* October 1992
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*/
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#include <sys/param.h>
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#include <sys/namei.h>
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#include <sys/buf.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/systm.h>
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#include <msdosfs/bpb.h>
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#include <msdosfs/direntry.h>
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#include <msdosfs/denode.h>
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#include <msdosfs/msdosfsmount.h>
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#include <msdosfs/fat.h>
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/*
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* When we search a directory the blocks containing directory entries are
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* read and examined. The directory entries contain information that would
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* normally be in the inode of a unix filesystem. This means that some of
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* a directory's contents may also be in memory resident denodes (sort of
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* an inode). This can cause problems if we are searching while some other
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* process is modifying a directory. To prevent one process from accessing
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* incompletely modified directory information we depend upon being the
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* soul owner of a directory block. bread/brelse provide this service.
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* This being the case, when a process modifies a directory it must first
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* acquire the disk block that contains the directory entry to be modified.
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* Then update the disk block and the denode, and then write the disk block
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* out to disk. This way disk blocks containing directory entries and in
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* memory denode's will be in synch.
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*/
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int
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msdosfs_lookup(ap)
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struct vop_lookup_args /* {
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struct vnode *a_dvp;
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struct vnode **a_vpp;
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struct componentname *a_cnp;
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} */ *ap;
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{
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struct vnode *vdp = ap->a_dvp;
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struct vnode **vpp = ap->a_vpp;
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struct componentname *cnp = ap->a_cnp;
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daddr_t bn;
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int error;
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int lockparent;
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int wantparent;
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int slotstatus;
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#define NONE 0
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#define FOUND 1
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int slotoffset = -1;
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int slotcluster = -1;
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int frcn;
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u_long cluster;
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int rootreloff;
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int diroff;
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int isadir; /* ~0 if found direntry is a directory */
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u_long scn; /* starting cluster number */
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struct vnode *pdp;
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struct denode *dp;
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struct denode *tdp;
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struct msdosfsmount *pmp;
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struct buf *bp = 0;
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struct direntry *dep = NULL;
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u_char dosfilename[12];
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int flags = cnp->cn_flags;
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int nameiop = cnp->cn_nameiop;
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr);
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#endif
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dp = VTODE(vdp);
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pmp = dp->de_pmp;
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*vpp = NULL;
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lockparent = flags & LOCKPARENT;
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wantparent = flags & (LOCKPARENT | WANTPARENT);
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): vdp %08x, dp %08x, Attr %02x\n",
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vdp, dp, dp->de_Attributes);
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#endif
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/*
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* Be sure vdp is a directory. Since dos filesystems don't have
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* the concept of execute permission anybody can search a
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* directory.
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*/
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if ((dp->de_Attributes & ATTR_DIRECTORY) == 0)
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return ENOTDIR;
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/*
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* See if the component of the pathname we are looking for is in
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* the directory cache. If so then do a few things and return.
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*/
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error = cache_lookup(vdp, vpp, cnp);
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if (error) {
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int vpid;
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if (error == ENOENT)
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return error;
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pdp = vdp;
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vdp = *vpp;
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dp = VTODE(vdp);
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vpid = vdp->v_id;
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if (pdp == vdp) {
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VREF(vdp);
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error = 0;
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} else if (flags & ISDOTDOT) {
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VOP_UNLOCK(pdp);
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error = vget(vdp, 1);
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if (!error && lockparent && (flags & ISLASTCN))
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error = VOP_LOCK(pdp);
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} else {
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error = vget(vdp, 1);
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if (!lockparent || error || !(flags & ISLASTCN))
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VOP_UNLOCK(pdp);
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}
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if (!error) {
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if (vpid == vdp->v_id) {
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): cache hit, vnode %08x, file %s\n",
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vdp, dp->de_Name);
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#endif
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return 0;
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}
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vput(vdp);
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if (lockparent && pdp != vdp && (flags & ISLASTCN))
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VOP_UNLOCK(pdp);
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}
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error = VOP_LOCK(pdp);
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if (error)
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return error;
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vdp = pdp;
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dp = VTODE(vdp);
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*vpp = NULL;
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}
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/*
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* If they are going after the . or .. entry in the root directory,
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* they won't find it. DOS filesystems don't have them in the root
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* directory. So, we fake it. deget() is in on this scam too.
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*/
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if ((vdp->v_flag & VROOT) && cnp->cn_nameptr[0] == '.' &&
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(cnp->cn_namelen == 1 ||
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(cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
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isadir = ATTR_DIRECTORY;
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scn = MSDOSFSROOT;
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): looking for . or .. in root directory\n");
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#endif
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cluster = MSDOSFSROOT;
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diroff = MSDOSFSROOT_OFS;
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goto foundroot;
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}
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/*
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* Don't search for free slots unless we are creating a filename
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* and we are at the end of the pathname.
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*/
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slotstatus = FOUND;
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if ((nameiop == CREATE || nameiop == RENAME) && (flags & ISLASTCN)) {
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slotstatus = NONE;
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slotoffset = -1;
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}
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unix2dosfn((u_char *) cnp->cn_nameptr, dosfilename, cnp->cn_namelen);
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dosfilename[11] = 0;
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): dos version of filename %s, length %d\n",
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dosfilename, cnp->cn_namelen);
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#endif
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/*
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* Search the directory pointed at by vdp for the name pointed at
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* by cnp->cn_nameptr.
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*/
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tdp = NULL;
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/*
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* The outer loop ranges over the clusters that make up the
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* directory. Note that the root directory is different from all
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* other directories. It has a fixed number of blocks that are not
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* part of the pool of allocatable clusters. So, we treat it a
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* little differently. The root directory starts at "cluster" 0.
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*/
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rootreloff = 0;
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for (frcn = 0;; frcn++) {
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error = pcbmap(dp, frcn, &bn, &cluster);
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if (error) {
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if (error == E2BIG)
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break;
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return error;
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}
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error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,NOCRED,&bp);
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if (error)
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return error;
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for (diroff = 0; diroff < pmp->pm_depclust; diroff++) {
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dep = (struct direntry *) bp->b_data + diroff;
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/*
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* If the slot is empty and we are still looking
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* for an empty then remember this one. If the
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* slot is not empty then check to see if it
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* matches what we are looking for. If the slot
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* has never been filled with anything, then the
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* remainder of the directory has never been used,
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* so there is no point in searching it.
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*/
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if (dep->deName[0] == SLOT_EMPTY ||
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dep->deName[0] == SLOT_DELETED) {
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if (slotstatus != FOUND) {
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slotstatus = FOUND;
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if (cluster == MSDOSFSROOT)
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slotoffset = rootreloff;
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else
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slotoffset = diroff;
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slotcluster = cluster;
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}
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if (dep->deName[0] == SLOT_EMPTY) {
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brelse(bp);
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goto notfound;
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}
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} else {
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/*
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* Ignore volume labels (anywhere, not just
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* the root directory).
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*/
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if ((dep->deAttributes & ATTR_VOLUME) == 0 &&
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bcmp(dosfilename, dep->deName, 11) == 0) {
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): match diroff %d, rootreloff %d\n",
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diroff, rootreloff);
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#endif
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/*
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* Remember where this directory
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* entry came from for whoever did
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* this lookup. If this is the root
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* directory we are interested in
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* the offset relative to the
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* beginning of the directory (not
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* the beginning of the cluster).
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*/
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if (cluster == MSDOSFSROOT)
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diroff = rootreloff;
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dp->de_fndoffset = diroff;
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dp->de_fndclust = cluster;
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goto found;
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}
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}
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rootreloff++;
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} /* for (diroff = 0; .... */
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/*
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* Release the buffer holding the directory cluster just
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* searched.
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*/
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brelse(bp);
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} /* for (frcn = 0; ; frcn++) */
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notfound:;
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/*
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* We hold no disk buffers at this point.
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*/
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/*
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* If we get here we didn't find the entry we were looking for. But
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* that's ok if we are creating or renaming and are at the end of
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* the pathname and the directory hasn't been removed.
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*/
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): op %d, refcnt %d, slotstatus %d\n",
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nameiop, dp->de_refcnt, slotstatus);
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printf(" slotoffset %d, slotcluster %d\n",
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slotoffset, slotcluster);
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#endif
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if ((nameiop == CREATE || nameiop == RENAME) &&
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(flags & ISLASTCN) && dp->de_refcnt != 0) {
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if (slotstatus == NONE) {
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dp->de_fndoffset = (u_long)-1;
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dp->de_fndclust = (u_long)-1;
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} else {
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#ifdef MSDOSFS_DEBUG
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printf("msdosfs_lookup(): saving empty slot location\n");
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#endif
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dp->de_fndoffset = slotoffset;
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dp->de_fndclust = slotcluster;
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}
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/* dp->de_flag |= DE_UPDATE; never update dos directories */
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cnp->cn_flags |= SAVENAME;
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if (!lockparent)/* leave searched dir locked? */
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VOP_UNLOCK(vdp);
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return EJUSTRETURN;
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}
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/*
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* Insert name in cache as non-existant if not trying to create it.
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*/
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if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
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cache_enter(vdp, *vpp, cnp);
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return ENOENT;
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found: ;
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/*
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* NOTE: We still have the buffer with matched directory entry at
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* this point.
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*/
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isadir = dep->deAttributes & ATTR_DIRECTORY;
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scn = getushort(dep->deStartCluster);
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foundroot:;
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/*
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* If we entered at foundroot, then we are looking for the . or ..
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* entry of the filesystems root directory. isadir and scn were
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* setup before jumping here. And, bp is null. There is no buf
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* header.
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*/
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/*
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* If deleting and at the end of the path, then if we matched on
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* "." then don't deget() we would probably panic(). Otherwise
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* deget() the directory entry.
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*/
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if (nameiop == DELETE && (flags & ISLASTCN)) {
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if (dp->de_StartCluster == scn && isadir) { /* "." */
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VREF(vdp);
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*vpp = vdp;
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if (bp)
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brelse(bp);
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return 0;
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}
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error = deget(pmp, cluster, diroff, dep, &tdp);
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if (error) {
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if (bp)
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brelse(bp);
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return error;
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}
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*vpp = DETOV(tdp);
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if (!lockparent)
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VOP_UNLOCK(vdp);
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if (bp)
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brelse(bp);
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return 0;
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}
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/*
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* If renaming.
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*/
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if (nameiop == RENAME && wantparent && (flags & ISLASTCN)) {
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if (dp->de_StartCluster == scn && isadir) {
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if (bp)
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brelse(bp);
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return EISDIR;
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}
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error = deget(pmp, cluster, diroff, dep, &tdp);
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if (error) {
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if (bp)
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brelse(bp);
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return error;
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}
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*vpp = DETOV(tdp);
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cnp->cn_flags |= SAVENAME;
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if (!lockparent)
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VOP_UNLOCK(vdp);
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if (bp)
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brelse(bp);
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return 0;
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}
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/*
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* ?
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*/
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pdp = vdp;
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if (flags & ISDOTDOT) {
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VOP_UNLOCK(pdp);
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error = deget(pmp, cluster, diroff, dep, &tdp);
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if (error) {
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VOP_LOCK(pdp);
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if (bp)
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brelse(bp);
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return error;
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}
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if (lockparent && (flags & ISLASTCN)
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&& (error = VOP_LOCK(pdp))) {
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vput(DETOV(tdp));
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return error;
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}
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*vpp = DETOV(tdp);
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} else if (dp->de_StartCluster == scn && isadir) { /* "." */
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VREF(vdp);
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*vpp = vdp;
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} else {
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error = deget(pmp, cluster, diroff, dep, &tdp);
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if (error) {
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if (bp)
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brelse(bp);
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return error;
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}
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if (!lockparent || !(flags & ISLASTCN))
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VOP_UNLOCK(pdp);
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*vpp = DETOV(tdp);
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}
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if (bp)
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brelse(bp);
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/*
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* Insert name in cache if wanted.
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*/
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if (cnp->cn_flags & MAKEENTRY)
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cache_enter(vdp, *vpp, cnp);
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return 0;
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}
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/*
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* dep - directory entry to copy into the directory
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* ddep - directory to add to
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* depp - return the address of the denode for the created directory entry
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* if depp != 0
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*/
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int
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createde(dep, ddep, depp)
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struct denode *dep;
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struct denode *ddep;
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struct denode **depp;
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{
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int error;
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u_long dirclust, diroffset;
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struct direntry *ndep;
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struct msdosfsmount *pmp = ddep->de_pmp;
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struct buf *bp;
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#ifdef MSDOSFS_DEBUG
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printf("createde(dep %08x, ddep %08x, depp %08x)\n", dep, ddep, depp);
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#endif
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/*
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* If no space left in the directory then allocate another cluster
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* and chain it onto the end of the file. There is one exception
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* to this. That is, if the root directory has no more space it
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* can NOT be expanded. extendfile() checks for and fails attempts
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* to extend the root directory. We just return an error in that
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* case.
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*/
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if (ddep->de_fndclust == (u_long)-1) {
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error = extendfile(ddep, 1, &bp, &dirclust, DE_CLEAR);
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if (error)
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return error;
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ndep = (struct direntry *) bp->b_data;
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/*
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* Let caller know where we put the directory entry.
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*/
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ddep->de_fndclust = dirclust;
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ddep->de_fndoffset = diroffset = 0;
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/*
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* Update the size of the directory
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*/
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ddep->de_FileSize += pmp->pm_bpcluster;
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} else {
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/*
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* There is space in the existing directory. So, we just
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* read in the cluster with space. Copy the new directory
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* entry in. Then write it to disk. NOTE: DOS directories
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* do not get smaller as clusters are emptied.
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*/
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|
dirclust = ddep->de_fndclust;
|
|
diroffset = ddep->de_fndoffset;
|
|
|
|
error = readep(pmp, dirclust, diroffset, &bp, &ndep);
|
|
if (error)
|
|
return error;
|
|
}
|
|
DE_EXTERNALIZE(ndep, dep);
|
|
|
|
/*
|
|
* If they want us to return with the denode gotten.
|
|
*/
|
|
if (depp) {
|
|
error = deget(pmp, dirclust, diroffset, ndep, depp);
|
|
if (error)
|
|
return error;
|
|
}
|
|
error = bwrite(bp);
|
|
if (error) {
|
|
vput(DETOV(*depp)); /* free the vnode we got on error */
|
|
return error;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Read in a directory entry and mark it as being deleted.
|
|
*/
|
|
int
|
|
markdeleted(pmp, dirclust, diroffset)
|
|
struct msdosfsmount *pmp;
|
|
u_long dirclust;
|
|
u_long diroffset;
|
|
{
|
|
int error;
|
|
struct direntry *ep;
|
|
struct buf *bp;
|
|
|
|
error = readep(pmp, dirclust, diroffset, &bp, &ep);
|
|
if (error)
|
|
return error;
|
|
ep->deName[0] = SLOT_DELETED;
|
|
return bwrite(bp);
|
|
}
|
|
|
|
/*
|
|
* Remove a directory entry. At this point the file represented by the
|
|
* directory entry to be removed is still full length until no one has it
|
|
* open. When the file no longer being used msdosfs_inactive() is called
|
|
* and will truncate the file to 0 length. When the vnode containing the
|
|
* denode is needed for some other purpose by VFS it will call
|
|
* msdosfs_reclaim() which will remove the denode from the denode cache.
|
|
*/
|
|
int
|
|
removede(pdep,dep)
|
|
struct denode *pdep; /* directory where the entry is removed */
|
|
struct denode *dep; /* file to be removed */
|
|
{
|
|
struct msdosfsmount *pmp = pdep->de_pmp;
|
|
int error;
|
|
|
|
#ifdef MSDOSFS_DEBUG
|
|
printf("removede(): filename %s\n", dep->de_Name);
|
|
printf("removede(): dep %08x, ndpcluster %d, ndpoffset %d\n",
|
|
dep, pdep->de_fndclust, pdep->de_fndoffset);
|
|
#endif
|
|
|
|
/*
|
|
* Read the directory block containing the directory entry we are
|
|
* to make free. The nameidata structure holds the cluster number
|
|
* and directory entry index number of the entry to free.
|
|
*/
|
|
error = markdeleted(pmp, pdep->de_fndclust, pdep->de_fndoffset);
|
|
|
|
if (error == 0)
|
|
dep->de_refcnt--;
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Be sure a directory is empty except for "." and "..". Return 1 if empty,
|
|
* return 0 if not empty or error.
|
|
*/
|
|
int
|
|
dosdirempty(dep)
|
|
struct denode *dep;
|
|
{
|
|
int dei;
|
|
int error;
|
|
u_long cn;
|
|
daddr_t bn;
|
|
struct buf *bp;
|
|
struct msdosfsmount *pmp = dep->de_pmp;
|
|
struct direntry *dentp;
|
|
|
|
/*
|
|
* Since the filesize field in directory entries for a directory is
|
|
* zero, we just have to feel our way through the directory until
|
|
* we hit end of file.
|
|
*/
|
|
for (cn = 0;; cn++) {
|
|
error = pcbmap(dep, cn, &bn, 0);
|
|
if (error == E2BIG)
|
|
return 1; /* it's empty */
|
|
error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, NOCRED,
|
|
&bp);
|
|
if (error)
|
|
return error;
|
|
dentp = (struct direntry *) bp->b_data;
|
|
for (dei = 0; dei < pmp->pm_depclust; dei++) {
|
|
if (dentp->deName[0] != SLOT_DELETED) {
|
|
/*
|
|
* In dos directories an entry whose name
|
|
* starts with SLOT_EMPTY (0) starts the
|
|
* beginning of the unused part of the
|
|
* directory, so we can just return that it
|
|
* is empty.
|
|
*/
|
|
if (dentp->deName[0] == SLOT_EMPTY) {
|
|
brelse(bp);
|
|
return 1;
|
|
}
|
|
/*
|
|
* Any names other than "." and ".." in a
|
|
* directory mean it is not empty.
|
|
*/
|
|
if (bcmp(dentp->deName, ". ", 11) &&
|
|
bcmp(dentp->deName, ".. ", 11)) {
|
|
brelse(bp);
|
|
#ifdef MSDOSFS_DEBUG
|
|
printf("dosdirempty(): entry %d found %02x, %02x\n",
|
|
dei, dentp->deName[0], dentp->deName[1]);
|
|
#endif
|
|
return 0; /* not empty */
|
|
}
|
|
}
|
|
dentp++;
|
|
}
|
|
brelse(bp);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/*
|
|
* Check to see if the directory described by target is in some
|
|
* subdirectory of source. This prevents something like the following from
|
|
* succeeding and leaving a bunch or files and directories orphaned. mv
|
|
* /a/b/c /a/b/c/d/e/f Where c and f are directories.
|
|
*
|
|
* source - the inode for /a/b/c
|
|
* target - the inode for /a/b/c/d/e/f
|
|
*
|
|
* Returns 0 if target is NOT a subdirectory of source.
|
|
* Otherwise returns a non-zero error number.
|
|
* The target inode is always unlocked on return.
|
|
*/
|
|
int
|
|
doscheckpath(source, target)
|
|
struct denode *source;
|
|
struct denode *target;
|
|
{
|
|
daddr_t scn;
|
|
struct msdosfsmount *pmp;
|
|
struct direntry *ep;
|
|
struct denode *dep;
|
|
struct buf *bp = NULL;
|
|
int error = 0;
|
|
|
|
dep = target;
|
|
if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
|
|
(source->de_Attributes & ATTR_DIRECTORY) == 0) {
|
|
error = ENOTDIR;
|
|
goto out;
|
|
}
|
|
if (dep->de_StartCluster == source->de_StartCluster) {
|
|
error = EEXIST;
|
|
goto out;
|
|
}
|
|
if (dep->de_StartCluster == MSDOSFSROOT)
|
|
goto out;
|
|
for (;;) {
|
|
if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
|
|
error = ENOTDIR;
|
|
goto out;
|
|
}
|
|
pmp = dep->de_pmp;
|
|
scn = dep->de_StartCluster;
|
|
error = bread(pmp->pm_devvp, cntobn(pmp, scn),
|
|
pmp->pm_bpcluster, NOCRED, &bp);
|
|
if (error) {
|
|
break;
|
|
}
|
|
ep = (struct direntry *) bp->b_data + 1;
|
|
if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
|
|
bcmp(ep->deName, ".. ", 11) != 0) {
|
|
error = ENOTDIR;
|
|
break;
|
|
}
|
|
scn = getushort(ep->deStartCluster);
|
|
if (scn == source->de_StartCluster) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
if (scn == MSDOSFSROOT)
|
|
break;
|
|
vput(DETOV(dep));
|
|
/* NOTE: deget() clears dep on error */
|
|
error = deget(pmp, scn, 0, ep, &dep);
|
|
brelse(bp);
|
|
bp = NULL;
|
|
if (error)
|
|
break;
|
|
}
|
|
out: ;
|
|
if (bp)
|
|
brelse(bp);
|
|
if (error == ENOTDIR)
|
|
printf("doscheckpath(): .. not a directory?\n");
|
|
if (dep != NULL)
|
|
vput(DETOV(dep));
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Read in the disk block containing the directory entry (dirclu, dirofs)
|
|
* and return the address of the buf header, and the address of the
|
|
* directory entry within the block.
|
|
*/
|
|
int
|
|
readep(pmp, dirclu, dirofs, bpp, epp)
|
|
struct msdosfsmount *pmp;
|
|
u_long dirclu, dirofs;
|
|
struct buf **bpp;
|
|
struct direntry **epp;
|
|
{
|
|
int error;
|
|
daddr_t bn;
|
|
|
|
bn = detobn(pmp, dirclu, dirofs);
|
|
error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, NOCRED, bpp);
|
|
if (error) {
|
|
*bpp = NULL;
|
|
return error;
|
|
}
|
|
if (epp)
|
|
*epp = bptoep(pmp, *bpp, dirofs);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Read in the disk block containing the directory entry dep came from and
|
|
* return the address of the buf header, and the address of the directory
|
|
* entry within the block.
|
|
*/
|
|
int
|
|
readde(dep, bpp, epp)
|
|
struct denode *dep;
|
|
struct buf **bpp;
|
|
struct direntry **epp;
|
|
{
|
|
return readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
|
|
bpp, epp);
|
|
}
|