1184 lines
34 KiB
C
1184 lines
34 KiB
C
/* $NetBSD: ufs_lookup.c,v 1.31 2000/05/13 23:43:16 perseant Exp $ */
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/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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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 the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)ufs_lookup.c 8.9 (Berkeley) 8/11/94
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/namei.h>
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#include <sys/buf.h>
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#include <sys/file.h>
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#include <sys/stat.h>
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#include <sys/mount.h>
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#include <sys/vnode.h>
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#include <sys/kernel.h>
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#include <vm/vm.h>
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#include <uvm/uvm_extern.h>
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#include <ufs/ufs/quota.h>
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#include <ufs/ufs/inode.h>
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#include <ufs/ufs/dir.h>
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#include <ufs/ufs/ufsmount.h>
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#include <ufs/ufs/ufs_extern.h>
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#include <ufs/ufs/ufs_bswap.h>
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struct nchstats nchstats;
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#ifdef DIAGNOSTIC
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int dirchk = 1;
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#else
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int dirchk = 0;
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#endif
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#define FSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
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/*
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* Convert a component of a pathname into a pointer to a locked inode.
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* This is a very central and rather complicated routine.
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* If the file system is not maintained in a strict tree hierarchy,
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* this can result in a deadlock situation (see comments in code below).
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*
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* The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
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* on whether the name is to be looked up, created, renamed, or deleted.
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* When CREATE, RENAME, or DELETE is specified, information usable in
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* creating, renaming, or deleting a directory entry may be calculated.
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* If flag has LOCKPARENT or'ed into it and the target of the pathname
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* exists, lookup returns both the target and its parent directory locked.
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* When creating or renaming and LOCKPARENT is specified, the target may
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* not be ".". When deleting and LOCKPARENT is specified, the target may
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* be "."., but the caller must check to ensure it does an vrele and vput
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* instead of two vputs.
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*
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* Overall outline of ufs_lookup:
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*
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* check accessibility of directory
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* look for name in cache, if found, then if at end of path
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* and deleting or creating, drop it, else return name
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* search for name in directory, to found or notfound
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* notfound:
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* if creating, return locked directory, leaving info on available slots
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* else return error
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* found:
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* if at end of path and deleting, return information to allow delete
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* if at end of path and rewriting (RENAME and LOCKPARENT), lock target
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* inode and return info to allow rewrite
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* if not at end, add name to cache; if at end and neither creating
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* nor deleting, add name to cache
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*/
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int
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ufs_lookup(v)
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void *v;
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{
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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 = v;
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struct vnode *vdp; /* vnode for directory being searched */
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struct inode *dp; /* inode for directory being searched */
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struct buf *bp; /* a buffer of directory entries */
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struct direct *ep; /* the current directory entry */
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int entryoffsetinblock; /* offset of ep in bp's buffer */
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enum {NONE, COMPACT, FOUND} slotstatus;
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doff_t slotoffset; /* offset of area with free space */
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int slotsize; /* size of area at slotoffset */
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int slotfreespace; /* amount of space free in slot */
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int slotneeded; /* size of the entry we're seeking */
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int numdirpasses; /* strategy for directory search */
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doff_t endsearch; /* offset to end directory search */
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doff_t prevoff; /* prev entry dp->i_offset */
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struct vnode *pdp; /* saved dp during symlink work */
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struct vnode *tdp; /* returned by VFS_VGET */
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doff_t enduseful; /* pointer past last used dir slot */
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u_long bmask; /* block offset mask */
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int lockparent; /* 1 => lockparent flag is set */
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int wantparent; /* 1 => wantparent or lockparent flag */
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int namlen, error;
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struct vnode **vpp = ap->a_vpp;
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struct componentname *cnp = ap->a_cnp;
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struct ucred *cred = cnp->cn_cred;
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int flags;
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int nameiop = cnp->cn_nameiop;
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const int needswap = UFS_MPNEEDSWAP(ap->a_dvp->v_mount);
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cnp->cn_flags &= ~PDIRUNLOCK;
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flags = cnp->cn_flags;
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bp = NULL;
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slotoffset = -1;
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*vpp = NULL;
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vdp = ap->a_dvp;
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dp = VTOI(vdp);
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lockparent = flags & LOCKPARENT;
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wantparent = flags & (LOCKPARENT|WANTPARENT);
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/*
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* Check accessiblity of directory.
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*/
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if ((error = VOP_ACCESS(vdp, VEXEC, cred, cnp->cn_proc)) != 0)
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return (error);
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if ((flags & ISLASTCN) && (vdp->v_mount->mnt_flag & MNT_RDONLY) &&
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(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
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return (EROFS);
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/*
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* We now have a segment name to search for, and a directory to search.
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*
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* Before tediously performing a linear scan of the directory,
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* check the name cache to see if the directory/name pair
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* we are looking for is known already.
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*/
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if ((error = cache_lookup(vdp, vpp, cnp)) >= 0)
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return (error);
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/*
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* Suppress search for slots unless creating
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* file and at end of pathname, in which case
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* we watch for a place to put the new file in
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* case it doesn't already exist.
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*/
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slotstatus = FOUND;
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slotfreespace = slotsize = slotneeded = 0;
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if ((nameiop == CREATE || nameiop == RENAME) &&
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(flags & ISLASTCN)) {
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slotstatus = NONE;
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slotneeded = (sizeof(struct direct) - MAXNAMLEN +
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cnp->cn_namelen + 3) &~ 3;
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}
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/*
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* If there is cached information on a previous search of
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* this directory, pick up where we last left off.
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* We cache only lookups as these are the most common
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* and have the greatest payoff. Caching CREATE has little
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* benefit as it usually must search the entire directory
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* to determine that the entry does not exist. Caching the
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* location of the last DELETE or RENAME has not reduced
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* profiling time and hence has been removed in the interest
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* of simplicity.
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*/
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bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
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if (nameiop != LOOKUP || dp->i_diroff == 0 ||
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dp->i_diroff > dp->i_ffs_size) {
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entryoffsetinblock = 0;
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dp->i_offset = 0;
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numdirpasses = 1;
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} else {
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dp->i_offset = dp->i_diroff;
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if ((entryoffsetinblock = dp->i_offset & bmask) &&
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(error = VOP_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)))
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return (error);
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numdirpasses = 2;
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nchstats.ncs_2passes++;
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}
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prevoff = dp->i_offset;
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endsearch = roundup(dp->i_ffs_size, DIRBLKSIZ);
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enduseful = 0;
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searchloop:
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while (dp->i_offset < endsearch) {
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/*
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* If necessary, get the next directory block.
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*/
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if ((dp->i_offset & bmask) == 0) {
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if (bp != NULL)
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brelse(bp);
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error = VOP_BLKATOFF(vdp, (off_t)dp->i_offset, NULL,
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&bp);
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if (error)
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return (error);
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entryoffsetinblock = 0;
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}
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/*
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* If still looking for a slot, and at a DIRBLKSIZE
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* boundary, have to start looking for free space again.
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*/
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if (slotstatus == NONE &&
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(entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
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slotoffset = -1;
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slotfreespace = 0;
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}
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/*
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* Get pointer to next entry.
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* Full validation checks are slow, so we only check
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* enough to insure forward progress through the
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* directory. Complete checks can be run by patching
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* "dirchk" to be true.
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*/
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ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock);
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if (ep->d_reclen == 0 ||
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(dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) {
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int i;
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ufs_dirbad(dp, dp->i_offset, "mangled entry");
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i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
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dp->i_offset += i;
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entryoffsetinblock += i;
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continue;
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}
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/*
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* If an appropriate sized slot has not yet been found,
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* check to see if one is available. Also accumulate space
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* in the current block so that we can determine if
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* compaction is viable.
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*/
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if (slotstatus != FOUND) {
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int size = ufs_rw16(ep->d_reclen, needswap);
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if (ep->d_ino != 0)
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size -= DIRSIZ(FSFMT(vdp), ep, needswap);
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if (size > 0) {
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if (size >= slotneeded) {
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slotstatus = FOUND;
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slotoffset = dp->i_offset;
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slotsize = ufs_rw16(ep->d_reclen,
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needswap);
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} else if (slotstatus == NONE) {
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slotfreespace += size;
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if (slotoffset == -1)
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slotoffset = dp->i_offset;
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if (slotfreespace >= slotneeded) {
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slotstatus = COMPACT;
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slotsize = dp->i_offset +
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ufs_rw16(ep->d_reclen,
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needswap)
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- slotoffset;
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}
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}
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}
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}
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/*
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* Check for a name match.
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*/
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if (ep->d_ino) {
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#if (BYTE_ORDER == LITTLE_ENDIAN)
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if (vdp->v_mount->mnt_maxsymlinklen > 0 ||
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needswap != 0)
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namlen = ep->d_namlen;
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else
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namlen = ep->d_type;
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#else
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if (vdp->v_mount->mnt_maxsymlinklen <= 0
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&& needswap != 0)
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namlen = ep->d_type;
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else
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namlen = ep->d_namlen;
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#endif
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if (namlen == cnp->cn_namelen &&
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!memcmp(cnp->cn_nameptr, ep->d_name,
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(unsigned)namlen)) {
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/*
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* Save directory entry's inode number and
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* reclen in ndp->ni_ufs area, and release
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* directory buffer.
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*/
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if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
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ep->d_type == DT_WHT) {
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slotstatus = FOUND;
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slotoffset = dp->i_offset;
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slotsize = ufs_rw16(ep->d_reclen,
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needswap);
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dp->i_reclen = slotsize;
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/*
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* This is used to set dp->i_endoff,
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* which may be used by ufs_direnter2()
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* as a length to truncate the
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* directory to. Therefore, it must
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* point past the end of the last
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* non-empty directory entry. We don't
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* know where that is in this case, so
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* we effectively disable shrinking by
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* using the existing size of the
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* directory.
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*
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* Note that we wouldn't expect to
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* shrink the directory while rewriting
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* an existing entry anyway.
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*/
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enduseful = endsearch;
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ap->a_cnp->cn_flags |= ISWHITEOUT;
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numdirpasses--;
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goto notfound;
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}
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dp->i_ino = ufs_rw32(ep->d_ino, needswap);
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dp->i_reclen = ufs_rw16(ep->d_reclen, needswap);
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brelse(bp);
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goto found;
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}
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}
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prevoff = dp->i_offset;
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dp->i_offset += ufs_rw16(ep->d_reclen, needswap);
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entryoffsetinblock += ufs_rw16(ep->d_reclen, needswap);
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if (ep->d_ino)
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enduseful = dp->i_offset;
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}
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notfound:
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/*
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* If we started in the middle of the directory and failed
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* to find our target, we must check the beginning as well.
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*/
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if (numdirpasses == 2) {
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numdirpasses--;
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dp->i_offset = 0;
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endsearch = dp->i_diroff;
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goto searchloop;
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}
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if (bp != NULL)
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brelse(bp);
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/*
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* If creating, and at end of pathname and current
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* directory has not been removed, then can consider
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* allowing file to be created.
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*/
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if ((nameiop == CREATE || nameiop == RENAME ||
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(nameiop == DELETE &&
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(ap->a_cnp->cn_flags & DOWHITEOUT) &&
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(ap->a_cnp->cn_flags & ISWHITEOUT))) &&
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(flags & ISLASTCN) && dp->i_ffs_effnlink != 0) {
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/*
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* Access for write is interpreted as allowing
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* creation of files in the directory.
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*/
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error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_proc);
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if (error)
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return (error);
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/*
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* Return an indication of where the new directory
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* entry should be put. If we didn't find a slot,
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* then set dp->i_count to 0 indicating
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* that the new slot belongs at the end of the
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* directory. If we found a slot, then the new entry
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* can be put in the range from dp->i_offset to
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* dp->i_offset + dp->i_count.
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*/
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if (slotstatus == NONE) {
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dp->i_offset = roundup(dp->i_ffs_size, DIRBLKSIZ);
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dp->i_count = 0;
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enduseful = dp->i_offset;
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} else if (nameiop == DELETE) {
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dp->i_offset = slotoffset;
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if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
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dp->i_count = 0;
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else
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dp->i_count = dp->i_offset - prevoff;
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} else {
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dp->i_offset = slotoffset;
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dp->i_count = slotsize;
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if (enduseful < slotoffset + slotsize)
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enduseful = slotoffset + slotsize;
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}
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dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
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dp->i_flag |= IN_CHANGE | IN_UPDATE;
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/*
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* We return with the directory locked, so that
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* the parameters we set up above will still be
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* valid if we actually decide to do a direnter().
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* We return ni_vp == NULL to indicate that the entry
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* does not currently exist; we leave a pointer to
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* the (locked) directory inode in ndp->ni_dvp.
|
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* The pathname buffer is saved so that the name
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* can be obtained later.
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*
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* NB - if the directory is unlocked, then this
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* information cannot be used.
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*/
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cnp->cn_flags |= SAVENAME;
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if (!lockparent) {
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VOP_UNLOCK(vdp, 0);
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cnp->cn_flags |= PDIRUNLOCK;
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}
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return (EJUSTRETURN);
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}
|
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/*
|
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* Insert name into cache (as non-existent) if appropriate.
|
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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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if (numdirpasses == 2)
|
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nchstats.ncs_pass2++;
|
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/*
|
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* Check that directory length properly reflects presence
|
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* of this entry.
|
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*/
|
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if (entryoffsetinblock + DIRSIZ(FSFMT(vdp), ep, needswap) >
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dp->i_ffs_size) {
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ufs_dirbad(dp, dp->i_offset, "i_size too small");
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dp->i_ffs_size = entryoffsetinblock +
|
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DIRSIZ(FSFMT(vdp), ep, needswap);
|
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dp->i_flag |= IN_CHANGE | IN_UPDATE;
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}
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|
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/*
|
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* Found component in pathname.
|
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* If the final component of path name, save information
|
|
* in the cache as to where the entry was found.
|
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*/
|
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if ((flags & ISLASTCN) && nameiop == LOOKUP)
|
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dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
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|
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/*
|
|
* If deleting, and at end of pathname, return
|
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* parameters which can be used to remove file.
|
|
* If the wantparent flag isn't set, we return only
|
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* the directory (in ndp->ni_dvp), otherwise we go
|
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* on and lock the inode, being careful with ".".
|
|
*/
|
|
if (nameiop == DELETE && (flags & ISLASTCN)) {
|
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/*
|
|
* Write access to directory required to delete files.
|
|
*/
|
|
error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_proc);
|
|
if (error)
|
|
return (error);
|
|
/*
|
|
* Return pointer to current entry in dp->i_offset,
|
|
* and distance past previous entry (if there
|
|
* is a previous entry in this block) in dp->i_count.
|
|
* Save directory inode pointer in ndp->ni_dvp for dirremove().
|
|
*/
|
|
if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
|
|
dp->i_count = 0;
|
|
else
|
|
dp->i_count = dp->i_offset - prevoff;
|
|
if (dp->i_number == dp->i_ino) {
|
|
VREF(vdp);
|
|
*vpp = vdp;
|
|
return (0);
|
|
}
|
|
if (flags & ISDOTDOT)
|
|
VOP_UNLOCK(vdp, 0); /* race to get the inode */
|
|
error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp);
|
|
if (flags & ISDOTDOT)
|
|
vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY);
|
|
if (error)
|
|
return (error);
|
|
/*
|
|
* If directory is "sticky", then user must own
|
|
* the directory, or the file in it, else she
|
|
* may not delete it (unless she's root). This
|
|
* implements append-only directories.
|
|
*/
|
|
if ((dp->i_ffs_mode & ISVTX) &&
|
|
cred->cr_uid != 0 &&
|
|
cred->cr_uid != dp->i_ffs_uid &&
|
|
VTOI(tdp)->i_ffs_uid != cred->cr_uid) {
|
|
vput(tdp);
|
|
return (EPERM);
|
|
}
|
|
*vpp = tdp;
|
|
if (!lockparent) {
|
|
VOP_UNLOCK(vdp, 0);
|
|
cnp->cn_flags |= PDIRUNLOCK;
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* If rewriting (RENAME), return the inode and the
|
|
* information required to rewrite the present directory
|
|
* Must get inode of directory entry to verify it's a
|
|
* regular file, or empty directory.
|
|
*/
|
|
if (nameiop == RENAME && wantparent && (flags & ISLASTCN)) {
|
|
error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_proc);
|
|
if (error)
|
|
return (error);
|
|
/*
|
|
* Careful about locking second inode.
|
|
* This can only occur if the target is ".".
|
|
*/
|
|
if (dp->i_number == dp->i_ino)
|
|
return (EISDIR);
|
|
if (flags & ISDOTDOT)
|
|
VOP_UNLOCK(vdp, 0); /* race to get the inode */
|
|
error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp);
|
|
if (flags & ISDOTDOT)
|
|
vn_lock(vdp, LK_EXCLUSIVE | LK_RETRY);
|
|
if (error)
|
|
return (error);
|
|
*vpp = tdp;
|
|
cnp->cn_flags |= SAVENAME;
|
|
if (!lockparent) {
|
|
VOP_UNLOCK(vdp, 0);
|
|
cnp->cn_flags |= PDIRUNLOCK;
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Step through the translation in the name. We do not `vput' the
|
|
* directory because we may need it again if a symbolic link
|
|
* is relative to the current directory. Instead we save it
|
|
* unlocked as "pdp". We must get the target inode before unlocking
|
|
* the directory to insure that the inode will not be removed
|
|
* before we get it. We prevent deadlock by always fetching
|
|
* inodes from the root, moving down the directory tree. Thus
|
|
* when following backward pointers ".." we must unlock the
|
|
* parent directory before getting the requested directory.
|
|
* There is a potential race condition here if both the current
|
|
* and parent directories are removed before the VFS_VGET for the
|
|
* inode associated with ".." returns. We hope that this occurs
|
|
* infrequently since we cannot avoid this race condition without
|
|
* implementing a sophisticated deadlock detection algorithm.
|
|
* Note also that this simple deadlock detection scheme will not
|
|
* work if the file system has any hard links other than ".."
|
|
* that point backwards in the directory structure.
|
|
*/
|
|
pdp = vdp;
|
|
if (flags & ISDOTDOT) {
|
|
VOP_UNLOCK(pdp, 0); /* race to get the inode */
|
|
cnp->cn_flags |= PDIRUNLOCK;
|
|
error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp);
|
|
if (error) {
|
|
if (vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY) == 0)
|
|
cnp->cn_flags &= ~PDIRUNLOCK;
|
|
return (error);
|
|
}
|
|
if (lockparent && (flags & ISLASTCN)) {
|
|
if ((error = vn_lock(pdp, LK_EXCLUSIVE))) {
|
|
vput(tdp);
|
|
return (error);
|
|
}
|
|
cnp->cn_flags &= ~PDIRUNLOCK;
|
|
}
|
|
*vpp = tdp;
|
|
} else if (dp->i_number == dp->i_ino) {
|
|
VREF(vdp); /* we want ourself, ie "." */
|
|
*vpp = vdp;
|
|
} else {
|
|
error = VFS_VGET(vdp->v_mount, dp->i_ino, &tdp);
|
|
if (error)
|
|
return (error);
|
|
if (!lockparent || !(flags & ISLASTCN)) {
|
|
VOP_UNLOCK(pdp, 0);
|
|
cnp->cn_flags |= PDIRUNLOCK;
|
|
}
|
|
*vpp = tdp;
|
|
}
|
|
|
|
/*
|
|
* Insert name into cache if appropriate.
|
|
*/
|
|
if (cnp->cn_flags & MAKEENTRY)
|
|
cache_enter(vdp, *vpp, cnp);
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
ufs_dirbad(ip, offset, how)
|
|
struct inode *ip;
|
|
doff_t offset;
|
|
char *how;
|
|
{
|
|
struct mount *mp;
|
|
|
|
mp = ITOV(ip)->v_mount;
|
|
printf("%s: bad dir ino %d at offset %d: %s\n",
|
|
mp->mnt_stat.f_mntonname, ip->i_number, offset, how);
|
|
if ((mp->mnt_stat.f_flags & MNT_RDONLY) == 0)
|
|
panic("bad dir");
|
|
}
|
|
|
|
/*
|
|
* Do consistency checking on a directory entry:
|
|
* record length must be multiple of 4
|
|
* entry must fit in rest of its DIRBLKSIZ block
|
|
* record must be large enough to contain entry
|
|
* name is not longer than MAXNAMLEN
|
|
* name must be as long as advertised, and null terminated
|
|
*/
|
|
int
|
|
ufs_dirbadentry(dp, ep, entryoffsetinblock)
|
|
struct vnode *dp;
|
|
struct direct *ep;
|
|
int entryoffsetinblock;
|
|
{
|
|
int i;
|
|
int namlen;
|
|
const int needswap = UFS_MPNEEDSWAP(dp->v_mount);
|
|
|
|
#if (BYTE_ORDER == LITTLE_ENDIAN)
|
|
if (dp->v_mount->mnt_maxsymlinklen > 0 || needswap != 0)
|
|
namlen = ep->d_namlen;
|
|
else
|
|
namlen = ep->d_type;
|
|
#else
|
|
if (dp->v_mount->mnt_maxsymlinklen <= 0 && needswap != 0)
|
|
namlen = ep->d_type;
|
|
else
|
|
namlen = ep->d_namlen;
|
|
#endif
|
|
if ((ufs_rw16(ep->d_reclen, needswap) & 0x3) != 0 ||
|
|
ufs_rw16(ep->d_reclen, needswap) >
|
|
DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
|
|
ufs_rw16(ep->d_reclen, needswap) <
|
|
DIRSIZ(FSFMT(dp), ep, needswap) ||
|
|
namlen > MAXNAMLEN) {
|
|
/*return (1); */
|
|
printf("First bad, reclen=%x, DIRSIZ=%lu, namlen=%d, flags=%x "
|
|
"entryoffsetinblock=%d\n",
|
|
ufs_rw16(ep->d_reclen, needswap),
|
|
(u_long)DIRSIZ(FSFMT(dp), ep, needswap),
|
|
namlen, dp->v_mount->mnt_flag, entryoffsetinblock);
|
|
goto bad;
|
|
}
|
|
if (ep->d_ino == 0)
|
|
return (0);
|
|
for (i = 0; i < namlen; i++)
|
|
if (ep->d_name[i] == '\0') {
|
|
/*return (1); */
|
|
printf("Second bad\n");
|
|
goto bad;
|
|
}
|
|
if (ep->d_name[i])
|
|
goto bad;
|
|
return (0);
|
|
bad:
|
|
return (1);
|
|
}
|
|
|
|
/*
|
|
* Construct a new directory entry after a call to namei, using the
|
|
* parameters that it left in the componentname argument cnp. The
|
|
* argument ip is the inode to which the new directory entry will refer.
|
|
*/
|
|
void
|
|
ufs_makedirentry(ip, cnp, newdirp)
|
|
struct inode *ip;
|
|
struct componentname *cnp;
|
|
struct direct *newdirp;
|
|
{
|
|
#ifdef DIAGNOSTIC
|
|
if ((cnp->cn_flags & SAVENAME) == 0)
|
|
panic("makedirentry: missing name");
|
|
#endif
|
|
newdirp->d_ino = ip->i_number;
|
|
newdirp->d_namlen = cnp->cn_namelen;
|
|
memcpy(newdirp->d_name, cnp->cn_nameptr, (unsigned)cnp->cn_namelen + 1);
|
|
if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0)
|
|
newdirp->d_type = IFTODT(ip->i_ffs_mode);
|
|
else {
|
|
newdirp->d_type = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Write a directory entry after a call to namei, using the parameters
|
|
* that it left in nameidata. The argument dirp is the new directory
|
|
* entry contents. Dvp is a pointer to the directory to be written,
|
|
* which was left locked by namei. Remaining parameters (dp->i_offset,
|
|
* dp->i_count) indicate how the space for the new entry is to be obtained.
|
|
* Non-null bp indicates that a directory is being created (for the
|
|
* soft dependency code).
|
|
*/
|
|
int
|
|
ufs_direnter(dvp, tvp, dirp, cnp, newdirbp)
|
|
struct vnode *dvp;
|
|
struct vnode *tvp;
|
|
struct direct *dirp;
|
|
struct componentname *cnp;
|
|
struct buf *newdirbp;
|
|
{
|
|
struct ucred *cr;
|
|
struct proc *p;
|
|
int newentrysize;
|
|
struct inode *dp;
|
|
struct buf *bp;
|
|
u_int dsize;
|
|
struct direct *ep, *nep;
|
|
int error, ret, blkoff, loc, spacefree, flags;
|
|
char *dirbuf;
|
|
struct timespec ts;
|
|
const int needswap = UFS_MPNEEDSWAP(dvp->v_mount);
|
|
|
|
error = 0;
|
|
cr = cnp->cn_cred;
|
|
p = cnp->cn_proc;
|
|
|
|
dp = VTOI(dvp);
|
|
newentrysize = DIRSIZ(0, dirp, 0);
|
|
|
|
if (dp->i_count == 0) {
|
|
/*
|
|
* If dp->i_count is 0, then namei could find no
|
|
* space in the directory. Here, dp->i_offset will
|
|
* be on a directory block boundary and we will write the
|
|
* new entry into a fresh block.
|
|
*/
|
|
if (dp->i_offset & (DIRBLKSIZ - 1))
|
|
panic("ufs_direnter: newblk");
|
|
flags = B_CLRBUF;
|
|
if (!DOINGSOFTDEP(dvp))
|
|
flags |= B_SYNC;
|
|
if ((error = VOP_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ,
|
|
cr, flags, &bp)) != 0) {
|
|
if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
|
|
bdwrite(newdirbp);
|
|
return (error);
|
|
}
|
|
dp->i_ffs_size = dp->i_offset + DIRBLKSIZ;
|
|
dp->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
uvm_vnp_setsize(dvp, dp->i_ffs_size);
|
|
dirp->d_reclen = ufs_rw16(DIRBLKSIZ, needswap);
|
|
dirp->d_ino = ufs_rw32(dirp->d_ino, needswap);
|
|
if (dvp->v_mount->mnt_maxsymlinklen <= 0) {
|
|
#if (BYTE_ORDER == LITTLE_ENDIAN)
|
|
if (needswap == 0) {
|
|
#else
|
|
if (needswap != 0) {
|
|
#endif
|
|
u_char tmp = dirp->d_namlen;
|
|
dirp->d_namlen = dirp->d_type;
|
|
dirp->d_type = tmp;
|
|
}
|
|
}
|
|
blkoff = dp->i_offset &
|
|
(VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1);
|
|
memcpy((caddr_t)bp->b_data + blkoff, (caddr_t)dirp,
|
|
newentrysize);
|
|
if (DOINGSOFTDEP(dvp)) {
|
|
/*
|
|
* Ensure that the entire newly allocated block is a
|
|
* valid directory so that future growth within the
|
|
* block does not have to ensure that the block is
|
|
* written before the inode.
|
|
*/
|
|
blkoff += DIRBLKSIZ;
|
|
while (blkoff < bp->b_bcount) {
|
|
((struct direct *)
|
|
(bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
|
|
blkoff += DIRBLKSIZ;
|
|
}
|
|
softdep_setup_directory_add(bp, dp, dp->i_offset,
|
|
ufs_rw32(dirp->d_ino, needswap), newdirbp);
|
|
bdwrite(bp);
|
|
} else {
|
|
error = VOP_BWRITE(bp);
|
|
}
|
|
TIMEVAL_TO_TIMESPEC(&time, &ts);
|
|
ret = VOP_UPDATE(dvp, &ts, &ts, UPDATE_DIROP);
|
|
if (error == 0)
|
|
return (ret);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* If dp->i_count is non-zero, then namei found space for the new
|
|
* entry in the range dp->i_offset to dp->i_offset + dp->i_count
|
|
* in the directory. To use this space, we may have to compact
|
|
* the entries located there, by copying them together towards the
|
|
* beginning of the block, leaving the free space in one usable
|
|
* chunk at the end.
|
|
*/
|
|
|
|
/*
|
|
* Increase size of directory if entry eats into new space.
|
|
* This should never push the size past a new multiple of
|
|
* DIRBLKSIZE.
|
|
*
|
|
* N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
|
|
*/
|
|
if (dp->i_offset + dp->i_count > dp->i_ffs_size)
|
|
dp->i_ffs_size = dp->i_offset + dp->i_count;
|
|
/*
|
|
* Get the block containing the space for the new directory entry.
|
|
*/
|
|
error = VOP_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp);
|
|
if (error) {
|
|
if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
|
|
bdwrite(newdirbp);
|
|
return (error);
|
|
}
|
|
/*
|
|
* Find space for the new entry. In the simple case, the entry at
|
|
* offset base will have the space. If it does not, then namei
|
|
* arranged that compacting the region dp->i_offset to
|
|
* dp->i_offset + dp->i_count would yield the space.
|
|
*/
|
|
ep = (struct direct *)dirbuf;
|
|
dsize = DIRSIZ(FSFMT(dvp), ep, needswap);
|
|
spacefree = ufs_rw16(ep->d_reclen, needswap) - dsize;
|
|
for (loc = ufs_rw16(ep->d_reclen, needswap); loc < dp->i_count; ) {
|
|
nep = (struct direct *)(dirbuf + loc);
|
|
if (ep->d_ino) {
|
|
/* trim the existing slot */
|
|
ep->d_reclen = ufs_rw16(dsize, needswap);
|
|
ep = (struct direct *)((char *)ep + dsize);
|
|
} else {
|
|
/* overwrite; nothing there; header is ours */
|
|
spacefree += dsize;
|
|
}
|
|
dsize = DIRSIZ(FSFMT(dvp), nep, needswap);
|
|
spacefree += ufs_rw16(nep->d_reclen, needswap) - dsize;
|
|
loc += ufs_rw16(nep->d_reclen, needswap);
|
|
if (DOINGSOFTDEP(dvp))
|
|
softdep_change_directoryentry_offset(dp, dirbuf,
|
|
(caddr_t)nep, (caddr_t)ep, dsize);
|
|
else
|
|
memcpy((caddr_t)ep, (caddr_t)nep, dsize);
|
|
}
|
|
/*
|
|
* Update the pointer fields in the previous entry (if any),
|
|
* copy in the new entry, and write out the block.
|
|
*/
|
|
if (ep->d_ino == 0 ||
|
|
(ufs_rw32(ep->d_ino, needswap) == WINO &&
|
|
memcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
|
|
if (spacefree + dsize < newentrysize)
|
|
panic("ufs_direnter: compact1");
|
|
dirp->d_reclen = spacefree + dsize;
|
|
} else {
|
|
if (spacefree < newentrysize)
|
|
panic("ufs_direnter: compact2");
|
|
dirp->d_reclen = spacefree;
|
|
ep->d_reclen = ufs_rw16(dsize, needswap);
|
|
ep = (struct direct *)((char *)ep + dsize);
|
|
}
|
|
dirp->d_reclen = ufs_rw16(dirp->d_reclen, needswap);
|
|
dirp->d_ino = ufs_rw32(dirp->d_ino, needswap);
|
|
if (dvp->v_mount->mnt_maxsymlinklen <= 0) {
|
|
#if (BYTE_ORDER == LITTLE_ENDIAN)
|
|
if (needswap == 0) {
|
|
#else
|
|
if (needswap != 0) {
|
|
#endif
|
|
u_char tmp = dirp->d_namlen;
|
|
dirp->d_namlen = dirp->d_type;
|
|
dirp->d_type = tmp;
|
|
}
|
|
}
|
|
memcpy((caddr_t)ep, (caddr_t)dirp, (u_int)newentrysize);
|
|
if (DOINGSOFTDEP(dvp)) {
|
|
softdep_setup_directory_add(bp, dp,
|
|
dp->i_offset + (caddr_t)ep - dirbuf,
|
|
ufs_rw32(dirp->d_ino, needswap), newdirbp);
|
|
bdwrite(bp);
|
|
} else {
|
|
error = VOP_BWRITE(bp);
|
|
}
|
|
dp->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
/*
|
|
* If all went well, and the directory can be shortened, proceed
|
|
* with the truncation. Note that we have to unlock the inode for
|
|
* the entry that we just entered, as the truncation may need to
|
|
* lock other inodes which can lead to deadlock if we also hold a
|
|
* lock on the newly entered node.
|
|
*/
|
|
if (error == 0 && dp->i_endoff && dp->i_endoff < dp->i_ffs_size) {
|
|
if (tvp != NULL)
|
|
VOP_UNLOCK(tvp, 0);
|
|
(void) VOP_TRUNCATE(dvp, (off_t)dp->i_endoff, IO_SYNC, cr, p);
|
|
if (tvp != NULL)
|
|
vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Remove a directory entry after a call to namei, using
|
|
* the parameters which it left in nameidata. The entry
|
|
* dp->i_offset contains the offset into the directory of the
|
|
* entry to be eliminated. The dp->i_count field contains the
|
|
* size of the previous record in the directory. If this
|
|
* is 0, the first entry is being deleted, so we need only
|
|
* zero the inode number to mark the entry as free. If the
|
|
* entry is not the first in the directory, we must reclaim
|
|
* the space of the now empty record by adding the record size
|
|
* to the size of the previous entry.
|
|
*/
|
|
int
|
|
ufs_dirremove(dvp, ip, flags, isrmdir)
|
|
struct vnode *dvp;
|
|
struct inode *ip;
|
|
int flags;
|
|
int isrmdir;
|
|
{
|
|
struct inode *dp;
|
|
struct direct *ep;
|
|
struct buf *bp;
|
|
int error;
|
|
|
|
dp = VTOI(dvp);
|
|
|
|
if (flags & DOWHITEOUT) {
|
|
/*
|
|
* Whiteout entry: set d_ino to WINO.
|
|
*/
|
|
error = VOP_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep,
|
|
&bp);
|
|
if (error)
|
|
return (error);
|
|
ep->d_ino = ufs_rw32(WINO, UFS_MPNEEDSWAP(dvp->v_mount));
|
|
ep->d_type = DT_WHT;
|
|
goto out;
|
|
}
|
|
|
|
if ((error = VOP_BLKATOFF(dvp,
|
|
(off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0)
|
|
return (error);
|
|
|
|
if (dp->i_count == 0) {
|
|
/*
|
|
* First entry in block: set d_ino to zero.
|
|
*/
|
|
ep->d_ino = 0;
|
|
} else {
|
|
/*
|
|
* Collapse new free space into previous entry.
|
|
*/
|
|
ep->d_reclen =
|
|
ufs_rw16(ufs_rw16(ep->d_reclen,
|
|
UFS_MPNEEDSWAP(dvp->v_mount))
|
|
+ dp->i_reclen, UFS_MPNEEDSWAP(dvp->v_mount));
|
|
}
|
|
out:
|
|
if (DOINGSOFTDEP(dvp)) {
|
|
if (ip) {
|
|
ip->i_ffs_effnlink--;
|
|
softdep_change_linkcnt(ip);
|
|
softdep_setup_remove(bp, dp, ip, isrmdir);
|
|
}
|
|
bdwrite(bp);
|
|
} else {
|
|
if (ip) {
|
|
ip->i_ffs_effnlink--;
|
|
ip->i_ffs_nlink--;
|
|
ip->i_flag |= IN_CHANGE;
|
|
}
|
|
error = VOP_BWRITE(bp);
|
|
}
|
|
dp->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Rewrite an existing directory entry to point at the inode
|
|
* supplied. The parameters describing the directory entry are
|
|
* set up by a call to namei.
|
|
*/
|
|
int
|
|
ufs_dirrewrite(dp, oip, newinum, newtype, isrmdir)
|
|
struct inode *dp, *oip;
|
|
ino_t newinum;
|
|
int newtype;
|
|
int isrmdir;
|
|
{
|
|
struct buf *bp;
|
|
struct direct *ep;
|
|
struct vnode *vdp = ITOV(dp);
|
|
int error;
|
|
|
|
error = VOP_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp);
|
|
if (error)
|
|
return (error);
|
|
ep->d_ino = ufs_rw32(newinum, UFS_MPNEEDSWAP(vdp->v_mount));
|
|
if (vdp->v_mount->mnt_maxsymlinklen > 0)
|
|
ep->d_type = newtype;
|
|
oip->i_ffs_effnlink--;
|
|
if (DOINGSOFTDEP(vdp)) {
|
|
softdep_change_linkcnt(oip);
|
|
softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir);
|
|
bdwrite(bp);
|
|
} else {
|
|
oip->i_ffs_nlink--;
|
|
oip->i_flag |= IN_CHANGE;
|
|
error = VOP_BWRITE(bp);
|
|
}
|
|
dp->i_flag |= IN_CHANGE | IN_UPDATE;
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Check if a directory is empty or not.
|
|
* Inode supplied must be locked.
|
|
*
|
|
* Using a struct dirtemplate here is not precisely
|
|
* what we want, but better than using a struct direct.
|
|
*
|
|
* NB: does not handle corrupted directories.
|
|
*/
|
|
int
|
|
ufs_dirempty(ip, parentino, cred)
|
|
struct inode *ip;
|
|
ino_t parentino;
|
|
struct ucred *cred;
|
|
{
|
|
off_t off;
|
|
struct dirtemplate dbuf;
|
|
struct direct *dp = (struct direct *)&dbuf;
|
|
int error, namlen;
|
|
size_t count;
|
|
#define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
|
|
|
|
for (off = 0; off < ip->i_ffs_size;
|
|
off += ufs_rw16(dp->d_reclen, UFS_IPNEEDSWAP(ip))) {
|
|
error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
|
|
UIO_SYSSPACE, IO_NODELOCKED, cred, &count, (struct proc *)0);
|
|
/*
|
|
* Since we read MINDIRSIZ, residual must
|
|
* be 0 unless we're at end of file.
|
|
*/
|
|
if (error || count != 0)
|
|
return (0);
|
|
/* avoid infinite loops */
|
|
if (dp->d_reclen == 0)
|
|
return (0);
|
|
/* skip empty entries */
|
|
if (dp->d_ino == 0 ||
|
|
ufs_rw32(dp->d_ino, UFS_IPNEEDSWAP(ip)) == WINO)
|
|
continue;
|
|
/* accept only "." and ".." */
|
|
#if (BYTE_ORDER == LITTLE_ENDIAN)
|
|
if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0 ||
|
|
UFS_IPNEEDSWAP(ip) != 0)
|
|
namlen = dp->d_namlen;
|
|
else
|
|
namlen = dp->d_type;
|
|
#else
|
|
if (ITOV(ip)->v_mount->mnt_maxsymlinklen <= 0 &&
|
|
UFS_IPNEEDSWAP(ip) != 0)
|
|
namlen = dp->d_type;
|
|
else
|
|
namlen = dp->d_namlen;
|
|
#endif
|
|
if (namlen > 2)
|
|
return (0);
|
|
if (dp->d_name[0] != '.')
|
|
return (0);
|
|
/*
|
|
* At this point namlen must be 1 or 2.
|
|
* 1 implies ".", 2 implies ".." if second
|
|
* char is also "."
|
|
*/
|
|
if (namlen == 1 &&
|
|
ufs_rw32(dp->d_ino, UFS_IPNEEDSWAP(ip)) == ip->i_number)
|
|
continue;
|
|
if (dp->d_name[1] == '.' &&
|
|
ufs_rw32(dp->d_ino, UFS_IPNEEDSWAP(ip)) == parentino)
|
|
continue;
|
|
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(source, target, cred)
|
|
struct inode *source, *target;
|
|
struct ucred *cred;
|
|
{
|
|
struct vnode *vp = ITOV(target);
|
|
int error, rootino, namlen;
|
|
struct dirtemplate dirbuf;
|
|
const int needswap = UFS_MPNEEDSWAP(vp->v_mount);
|
|
|
|
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;
|
|
|
|
for (;;) {
|
|
if (vp->v_type != VDIR) {
|
|
error = ENOTDIR;
|
|
break;
|
|
}
|
|
error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
|
|
sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
|
|
IO_NODELOCKED, cred, NULL, (struct proc *)0);
|
|
if (error != 0)
|
|
break;
|
|
#if (BYTE_ORDER == LITTLE_ENDIAN)
|
|
if (vp->v_mount->mnt_maxsymlinklen > 0 ||
|
|
needswap != 0)
|
|
namlen = dirbuf.dotdot_namlen;
|
|
else
|
|
namlen = dirbuf.dotdot_type;
|
|
#else
|
|
if (vp->v_mount->mnt_maxsymlinklen == 0 &&
|
|
needswap != 0)
|
|
namlen = dirbuf.dotdot_type;
|
|
else
|
|
namlen = dirbuf.dotdot_namlen;
|
|
#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);
|
|
error = VFS_VGET(vp->v_mount,
|
|
ufs_rw32(dirbuf.dotdot_ino, needswap), &vp);
|
|
if (error) {
|
|
vp = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (error == ENOTDIR)
|
|
printf("checkpath: .. not a directory\n");
|
|
if (vp != NULL)
|
|
vput(vp);
|
|
return (error);
|
|
}
|