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lfs_inode.c revision 1.1
      1 /*      $NetBSD: lfs_inode.c,v 1.1 1999/09/29 04:57:49 perseant Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 1980, 1991, 1993, 1994
      5  *      The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by the University of
     18  *      California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) Copyright (c) 1980, 1991, 1993, 1994\n\
     39         The Regents of the University of California.  All rights reserved.\n");
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)main.c      8.6 (Berkeley) 5/1/95";
     45 #else
     46 __RCSID("$NetBSD: lfs_inode.c,v 1.1 1999/09/29 04:57:49 perseant Exp $");
     47 #endif
     48 #endif /* not lint */
     49 
     50 #include <sys/param.h>
     51 #include <sys/time.h>
     52 #include <sys/stat.h>
     53 #include <ufs/ufs/dir.h>
     54 #include <ufs/ufs/dinode.h>
     55 #include <sys/mount.h>
     56 #include <ufs/lfs/lfs.h>
     57 
     58 #include <protocols/dumprestore.h>
     59 
     60 #include <ctype.h>
     61 #include <errno.h>
     62 #include <fts.h>
     63 #include <stdio.h>
     64 #ifdef __STDC__
     65 #include <string.h>
     66 #include <unistd.h>
     67 #endif
     68 
     69 #include "dump.h"
     70 
     71 #define MAXIFPB        (MAXBSIZE / sizeof(IFILE))
     72 
     73 #define	HASDUMPEDFILE	0x1
     74 #define	HASSUBDIRS	0x2
     75 
     76 struct lfs *sblock;
     77 
     78 /*
     79  * Read the superblock from disk, and check its magic number.
     80  * Determine whether byte-swapping needs to be done on this filesystem.
     81  */
     82 int
     83 fs_read_sblock(char *sblock_buf)
     84 {
     85 	int needswap = 0;
     86 
     87 	sblock = (struct lfs *)sblock_buf;
     88 	rawread(LFS_LABELPAD, (char *) sblock, LFS_SBPAD);
     89 	if (sblock->lfs_magic != LFS_MAGIC) {
     90 #if 0
     91 		if (sblock->lfs_magic == bswap32(LFS_MAGIC)) {
     92 			lfs_sb_swap(sblock, sblock, 0);
     93 			needswap = 1;
     94 		} else
     95 #endif
     96 			quit("bad sblock magic number\n");
     97 	}
     98 	return needswap;
     99 }
    100 
    101 /*
    102  * Fill in the ufsi struct, as well as the maxino and dev_bsize global
    103  * variables.
    104  */
    105 struct ufsi *
    106 fs_parametrize(void)
    107 {
    108 	static struct ufsi ufsi;
    109 
    110 	ufsi.ufs_dsize = fsbtodb(sblock,sblock->lfs_size);
    111 	ufsi.ufs_bsize = sblock->lfs_bsize;
    112 	ufsi.ufs_bshift = sblock->lfs_bshift;
    113 	ufsi.ufs_fsize = sblock->lfs_fsize;
    114 	ufsi.ufs_frag = sblock->lfs_frag;
    115 	ufsi.ufs_fsatoda = 0;
    116 	ufsi.ufs_nindir = sblock->lfs_nindir;
    117 	ufsi.ufs_inopb = sblock->lfs_inopb;
    118 	ufsi.ufs_maxsymlinklen = sblock->lfs_maxsymlinklen;
    119 	ufsi.ufs_bmask = ~(sblock->lfs_bmask);
    120 	ufsi.ufs_qbmask = sblock->lfs_bmask;
    121 	ufsi.ufs_fmask = ~(sblock->lfs_ffmask);
    122 	ufsi.ufs_qfmask = sblock->lfs_ffmask;
    123 
    124 	dev_bsize = sblock->lfs_bsize >> sblock->lfs_fsbtodb;
    125 
    126 	return &ufsi;
    127 }
    128 
    129 ino_t
    130 fs_maxino(void)
    131 {
    132 	return ((getino(sblock->lfs_ifile)->di_size
    133 		   - (sblock->lfs_cleansz + sblock->lfs_segtabsz)
    134 		   * sblock->lfs_bsize)
    135 		  / sblock->lfs_bsize) * sblock->lfs_ifpb - 1;
    136 }
    137 
    138 /*
    139  * XXX KS - I know there's a better way to do this.
    140  */
    141 #define BASE_SINDIR (NDADDR)
    142 #define BASE_DINDIR (NDADDR+NINDIR(fs))
    143 #define BASE_TINDIR (NDADDR+NINDIR(fs)+NINDIR(fs)*NINDIR(fs))
    144 
    145 #define D_UNITS (NINDIR(fs))
    146 #define T_UNITS (NINDIR(fs)*NINDIR(fs))
    147 
    148 static daddr_t
    149 lfs_bmap(struct lfs *fs, struct dinode *idinode, ufs_daddr_t lbn)
    150 {
    151 	ufs_daddr_t residue, up;
    152 	int off=0;
    153 	char bp[MAXBSIZE];
    154 
    155 	if(lbn > 0 && lbn > (idinode->di_size-1)/dev_bsize) {
    156 		return UNASSIGNED;
    157 	}
    158 	/*
    159 	 * Indirect blocks: if it is a first-level indirect, pull its
    160 	 * address from the inode; otherwise, call ourselves to find the
    161 	 * address of the parent indirect block, and load that to find
    162 	 * the desired address.
    163 	 */
    164 	if(lbn < 0) {
    165 		lbn *= -1;
    166 		if(lbn == NDADDR) {
    167 			/* printf("lbn %d: single indir base\n", -lbn); */
    168 			return idinode->di_ib[0]; /* single indirect */
    169 		} else if(lbn == BASE_DINDIR+1) {
    170 			/* printf("lbn %d: double indir base\n", -lbn); */
    171 			return idinode->di_ib[1]; /* double indirect */
    172 		} else if(lbn == BASE_TINDIR+2) {
    173 			/* printf("lbn %d: triple indir base\n", -lbn); */
    174 			return idinode->di_ib[2]; /* triple indirect */
    175 		}
    176 
    177 		/*
    178 		 * Find the immediate parent. This is essentially finding the
    179 		 * residue of modulus, and then rounding accordingly.
    180 		 */
    181 		residue = (lbn-NDADDR) % NINDIR(fs);
    182 		if(residue == 1) {
    183 			/* Double indirect.  Parent is the triple. */
    184 			up = idinode->di_ib[2];
    185 			off = (lbn-2-BASE_TINDIR)/(NINDIR(fs)*NINDIR(fs));
    186 			if(up == UNASSIGNED || up == LFS_UNUSED_DADDR)
    187 				return UNASSIGNED;
    188 			/* printf("lbn %d: parent is the triple\n", -lbn); */
    189 			bread(up, bp, sblock->lfs_bsize);
    190 			return ((daddr_t *)bp)[off];
    191 		} else /* residue == 0 */ {
    192 			/* Single indirect.  Two cases. */
    193 			if(lbn < BASE_TINDIR) {
    194 				/* Parent is the double, simple */
    195 				up = -(BASE_DINDIR) - 1;
    196 				off = (lbn-BASE_DINDIR) / D_UNITS;
    197 				/* printf("lbn %d: parent is %d/%d\n", -lbn, up,off); */
    198 			} else {
    199 				/* Ancestor is the triple, more complex */
    200 				up = ((lbn-BASE_TINDIR) / T_UNITS)
    201 					* T_UNITS + BASE_TINDIR + 1;
    202 				off = (lbn/D_UNITS) - (up/D_UNITS);
    203 				up = -up;
    204 				/* printf("lbn %d: parent is %d/%d\n", -lbn, up,off); */
    205 			}
    206 		}
    207 	} else {
    208 		/* Direct block.  Its parent must be a single indirect. */
    209 		if(lbn < NDADDR)
    210 			return idinode->di_db[lbn];
    211 		else {
    212 			/* Parent is an indirect block. */
    213 			up = -(((lbn-NDADDR) / D_UNITS) * D_UNITS + NDADDR);
    214 			off = (lbn-NDADDR) % D_UNITS;
    215 			/* printf("lbn %d: parent is %d/%d\n", lbn,up,off); */
    216 		}
    217 	}
    218 	up = lfs_bmap(fs,idinode,up);
    219 	if(up == UNASSIGNED || up == LFS_UNUSED_DADDR)
    220 		return UNASSIGNED;
    221 	bread(up, bp, sblock->lfs_bsize);
    222 	return ((daddr_t *)bp)[off];
    223 }
    224 
    225 static struct ifile *
    226 lfs_ientry(ino_t ino)
    227 {
    228     static struct ifile ifileblock[MAXIFPB];
    229     static daddr_t ifblkno;
    230     ufs_daddr_t lbn;
    231     daddr_t blkno;
    232 
    233     lbn = ino/sblock->lfs_ifpb + sblock->lfs_cleansz + sblock->lfs_segtabsz;
    234     blkno = lfs_bmap(sblock,getino(sblock->lfs_ifile),lbn);
    235     if(blkno != ifblkno)
    236 	    bread(blkno, (char *)ifileblock, sblock->lfs_bsize);
    237     return ifileblock + (ino%sblock->lfs_ifpb);
    238 }
    239 
    240 /* Search a block for a specific dinode. */
    241 struct dinode *
    242 lfs_ifind(struct lfs *fs, ino_t ino, struct dinode *dip)
    243 {
    244 	register int cnt;
    245 
    246 	for(cnt=0;cnt<INOPB(fs);cnt++)
    247 		if(dip[cnt].di_inumber == ino)
    248 			return &(dip[cnt]);
    249 	return NULL;
    250 }
    251 
    252 struct dinode *
    253 getino(inum)
    254 	ino_t inum;
    255 {
    256 	static daddr_t inoblkno;
    257 	daddr_t blkno;
    258 	static struct dinode inoblock[MAXINOPB];
    259 	static struct dinode ifile_dinode; /* XXX fill this in */
    260 	static struct dinode empty_dinode; /* Always stays zeroed */
    261 	struct dinode *dp;
    262 	int i;
    263 
    264 	if(inum == sblock->lfs_ifile) {
    265 		/* Load the ifile inode if not already */
    266 		if(ifile_dinode.di_u.inumber == 0) {
    267 			blkno = sblock->lfs_idaddr;
    268 			bread(blkno, (char *)inoblock, (int)sblock->lfs_bsize);
    269 			dp = lfs_ifind(sblock, inum, inoblock);
    270 			ifile_dinode = *dp; /* Structure copy */
    271 		}
    272 		return &ifile_dinode;
    273 	}
    274 
    275 	curino = inum;
    276 	blkno = lfs_ientry(inum)->if_daddr;
    277 	if(blkno == LFS_UNUSED_DADDR)
    278 		return &empty_dinode;
    279 
    280 	if(blkno != inoblkno) {
    281 		bread(blkno, (char *)inoblock, (int)sblock->lfs_bsize);
    282 		if (needswap)
    283 			for (i = 0; i < MAXINOPB; i++)
    284 				ffs_dinode_swap(&inoblock[i], &inoblock[i]);
    285 	}
    286 	return lfs_ifind(sblock, inum, inoblock);
    287 }
    288