GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/makefs/msdos/msdosfs_denode.c Lines: 0 107 0.0 %
Date: 2017-11-13 Branches: 0 60 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: msdosfs_denode.c,v 1.6 2016/10/22 22:20:24 natano Exp $	*/
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/*	$NetBSD: msdosfs_denode.c,v 1.7 2015/03/29 05:52:59 agc Exp $	*/
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/*-
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 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
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 * Copyright (C) 1994, 1995, 1997 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 "ffs/buf.h"
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#include <msdosfs/bpb.h>
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#include "msdos/msdosfsmount.h"
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#include "msdos/direntry.h"
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#include "msdos/denode.h"
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#include "msdos/fat.h"
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#include <util.h>
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#include "makefs.h"
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/*
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 * If deget() succeeds it returns with the gotten denode locked().
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 *
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 * pmp	     - address of msdosfsmount structure of the filesystem containing
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 *	       the denode of interest.  The pm_dev field and the address of
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 *	       the msdosfsmount structure are used.
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 * dirclust  - which cluster bp contains, if dirclust is 0 (root directory)
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 *	       diroffset is relative to the beginning of the root directory,
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 *	       otherwise it is cluster relative.
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 * diroffset - offset past begin of cluster of denode we want
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 * depp	     - returns the address of the gotten denode.
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 */
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int
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deget(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
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    struct denode **depp)
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	/* pmp:	 so we know the maj/min number */
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	/* dirclust:		 cluster this dir entry came from */
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	/* diroffset:		 index of entry within the cluster */
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	/* depp:		 returns the addr of the gotten denode */
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{
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	int error;
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	struct direntry *direntptr;
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	struct denode *ldep;
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	struct mkfsbuf *bp;
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#ifdef MSDOSFS_DEBUG
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	printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
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	    pmp, dirclust, diroffset, depp);
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#endif
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	/*
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	 * On FAT32 filesystems, root is a (more or less) normal
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	 * directory
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	 */
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	if (FAT32(pmp) && dirclust == MSDOSFSROOT)
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		dirclust = pmp->pm_rootdirblk;
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	ldep = ecalloc(1, sizeof(*ldep));
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	ldep->de_mkfsvnode = NULL;
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	ldep->de_flag = 0;
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	ldep->de_devvp = 0;
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	ldep->de_lockf = 0;
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	ldep->de_dev = pmp->pm_dev;
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	ldep->de_dirclust = dirclust;
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	ldep->de_diroffset = diroffset;
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	ldep->de_pmp = pmp;
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	ldep->de_devvp = pmp->pm_devvp;
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	ldep->de_refcnt = 1;
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	fc_purge(ldep, 0);
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	/*
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	 * Copy the directory entry into the denode area of the mkfsvnode.
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	 */
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	if ((dirclust == MSDOSFSROOT
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	     || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
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	    && diroffset == MSDOSFSROOT_OFS) {
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		/*
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		 * Directory entry for the root directory. There isn't one,
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		 * so we manufacture one. We should probably rummage
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		 * through the root directory and find a label entry (if it
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		 * exists), and then use the time and date from that entry
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		 * as the time and date for the root denode.
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		 */
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		ldep->de_mkfsvnode = (struct mkfsvnode *)-1;
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		ldep->de_Attributes = ATTR_DIRECTORY;
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		if (FAT32(pmp))
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			ldep->de_StartCluster = pmp->pm_rootdirblk;
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			/* de_FileSize will be filled in further down */
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		else {
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			ldep->de_StartCluster = MSDOSFSROOT;
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			ldep->de_FileSize = pmp->pm_rootdirsize * pmp->pm_BytesPerSec;
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		}
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		/*
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		 * fill in time and date so that dos2unixtime() doesn't
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		 * spit up when called from msdosfs_getattr() with root
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		 * denode
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		 */
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		ldep->de_CHun = 0;
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		ldep->de_CTime = 0x0000;	/* 00:00:00	 */
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		ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
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		    | (1 << DD_DAY_SHIFT);
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		/* Jan 1, 1980	 */
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		ldep->de_ADate = ldep->de_CDate;
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		ldep->de_MTime = ldep->de_CTime;
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		ldep->de_MDate = ldep->de_CDate;
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		/* leave the other fields as garbage */
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	} else {
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		error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
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		if (error) {
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			ldep->de_devvp = NULL;
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			ldep->de_Name[0] = SLOT_DELETED;
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			return (error);
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		}
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		DE_INTERNALIZE(ldep, direntptr);
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		brelse(bp, 0);
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	}
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	/*
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	 * Fill in a few fields of the mkfsvnode and finish filling in the
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	 * denode.  Then return the address of the found denode.
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	 */
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	if (ldep->de_Attributes & ATTR_DIRECTORY) {
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		/*
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		 * Since DOS directory entries that describe directories
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		 * have 0 in the filesize field, we take this opportunity
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		 * to find out the length of the directory and plug it into
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		 * the denode structure.
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		 */
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		u_long size;
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		if (ldep->de_StartCluster != MSDOSFSROOT) {
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			error = pcbmap(ldep, CLUST_END, 0, &size, 0);
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			if (error == E2BIG) {
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				ldep->de_FileSize = de_cn2off(pmp, size);
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				error = 0;
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			} else
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				printf("deget(): pcbmap returned %d\n", error);
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		}
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	}
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	*depp = ldep;
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	return (0);
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}
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/*
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 * Truncate the file described by dep to the length specified by length.
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 */
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int
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detrunc(struct denode *dep, u_long length, int flags)
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{
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	int error;
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	int allerror = 0;
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	u_long eofentry;
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	u_long chaintofree = 0;
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	daddr_t bn, lastblock;
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	int boff;
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	int isadir = dep->de_Attributes & ATTR_DIRECTORY;
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	struct mkfsbuf *bp;
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	struct msdosfsmount *pmp = dep->de_pmp;
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#ifdef MSDOSFS_DEBUG
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	printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
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#endif
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	/*
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	 * Disallow attempts to truncate the root directory since it is of
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	 * fixed size.  That's just the way dos filesystems are.  We use
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	 * the VROOT bit in the mkfsvnode because checking for the directory
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	 * bit and a startcluster of 0 in the denode is not adequate to
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	 * recognize the root directory at this point in a file or
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	 * directory's life.
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	 */
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	if (dep->de_mkfsvnode != NULL && !FAT32(pmp)) {
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		printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
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		    dep->de_dirclust, dep->de_diroffset);
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		return (EINVAL);
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	}
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	if (dep->de_FileSize < length)
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		return (deextend(dep, length));
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	lastblock = de_clcount(pmp, length) - 1;
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	/*
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	 * If the desired length is 0 then remember the starting cluster of
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	 * the file and set the StartCluster field in the directory entry
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	 * to 0.  If the desired length is not zero, then get the number of
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	 * the last cluster in the shortened file.  Then get the number of
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	 * the first cluster in the part of the file that is to be freed.
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	 * Then set the next cluster pointer in the last cluster of the
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	 * file to CLUST_EOFE.
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	 */
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	if (length == 0) {
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		chaintofree = dep->de_StartCluster;
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		dep->de_StartCluster = 0;
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		eofentry = ~0;
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	} else {
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		error = pcbmap(dep, lastblock, 0, &eofentry, 0);
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		if (error) {
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#ifdef MSDOSFS_DEBUG
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			printf("detrunc(): pcbmap fails %d\n", error);
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#endif
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			return (error);
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		}
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	}
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	/*
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	 * If the new length is not a multiple of the cluster size then we
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	 * must zero the tail end of the new last cluster in case it
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	 * becomes part of the file again because of a seek.
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	 */
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	if ((boff = length & pmp->pm_crbomask) != 0) {
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		if (isadir) {
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			bn = cntobn(pmp, eofentry);
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			error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn),
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			    pmp->pm_bpcluster, B_MODIFY, &bp);
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			if (error) {
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#ifdef MSDOSFS_DEBUG
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				printf("detrunc(): bread fails %d\n", error);
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#endif
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				return (error);
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			}
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			memset((char *)bp->b_data + boff, 0,
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			    pmp->pm_bpcluster - boff);
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			if (flags & IO_SYNC)
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				bwrite(bp);
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			else
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				bdwrite(bp);
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		}
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	}
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	/*
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	 * Write out the updated directory entry.  Even if the update fails
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	 * we free the trailing clusters.
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	 */
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	dep->de_FileSize = length;
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	if (!isadir)
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		dep->de_flag |= DE_UPDATE|DE_MODIFIED;
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#ifdef MSDOSFS_DEBUG
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	printf("detrunc(): allerror %d, eofentry %lu\n",
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	       allerror, eofentry);
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#endif
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	/*
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	 * If we need to break the cluster chain for the file then do it
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	 * now.
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	 */
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	if (eofentry != (u_long)~0) {
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		error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
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				 &chaintofree, CLUST_EOFE);
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		if (error) {
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#ifdef MSDOSFS_DEBUG
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			printf("detrunc(): fatentry errors %d\n", error);
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#endif
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			return (error);
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		}
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	}
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	/*
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	 * Now free the clusters removed from the file because of the
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	 * truncation.
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	 */
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	if (chaintofree != 0 && !MSDOSFSEOF(chaintofree, pmp->pm_fatmask))
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		freeclusterchain(pmp, chaintofree);
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	return (allerror);
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}
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/*
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 * Extend the file described by dep to length specified by length.
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 */
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int
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deextend(struct denode *dep, u_long length)
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{
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	struct msdosfsmount *pmp = dep->de_pmp;
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	u_long count;
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	int error;
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	/*
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	 * The root of a DOS filesystem cannot be extended.
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	 */
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	if (dep->de_mkfsvnode != NULL && !FAT32(pmp))
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		return EINVAL;
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	/*
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	 * Directories cannot be extended.
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	 */
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	if (dep->de_Attributes & ATTR_DIRECTORY)
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		return EISDIR;
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	if (length <= dep->de_FileSize)
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		return E2BIG;
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	/*
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	 * Compute the number of clusters to allocate.
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	 */
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	count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
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	if (count > 0) {
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		if (count > pmp->pm_freeclustercount)
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			return (ENOSPC);
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		error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
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		if (error) {
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			/* truncate the added clusters away again */
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			(void) detrunc(dep, dep->de_FileSize, 0);
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			return (error);
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		}
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	}
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	/*
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	 * Zero extend file range; ubc_zerorange() uses ubc_alloc() and a
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	 * memset(); we set the write size so ubc won't read in file data that
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	 * is zero'd later.
355
	 */
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	dep->de_FileSize = length;
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	dep->de_flag |= DE_UPDATE|DE_MODIFIED;
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	return 0;
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}