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mkfs.c revision 1.107
      1 /*	$NetBSD: mkfs.c,v 1.107 2010/01/31 16:04:34 mlelstv Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1980, 1989, 1993
      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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 2002 Networks Associates Technology, Inc.
     34  * All rights reserved.
     35  *
     36  * This software was developed for the FreeBSD Project by Marshall
     37  * Kirk McKusick and Network Associates Laboratories, the Security
     38  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
     39  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
     40  * research program
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  */
     70 
     71 #include <sys/cdefs.h>
     72 #ifndef lint
     73 #if 0
     74 static char sccsid[] = "@(#)mkfs.c	8.11 (Berkeley) 5/3/95";
     75 #else
     76 __RCSID("$NetBSD: mkfs.c,v 1.107 2010/01/31 16:04:34 mlelstv Exp $");
     77 #endif
     78 #endif /* not lint */
     79 
     80 #include <sys/param.h>
     81 #include <sys/mman.h>
     82 #include <sys/time.h>
     83 #include <sys/resource.h>
     84 #include <ufs/ufs/dinode.h>
     85 #include <ufs/ufs/dir.h>
     86 #include <ufs/ufs/ufs_bswap.h>
     87 #include <ufs/ffs/fs.h>
     88 #include <ufs/ffs/ffs_extern.h>
     89 #include <sys/ioctl.h>
     90 #include <sys/disklabel.h>
     91 
     92 #include <err.h>
     93 #include <errno.h>
     94 #include <string.h>
     95 #include <unistd.h>
     96 #include <stdlib.h>
     97 #include <stddef.h>
     98 
     99 #ifndef STANDALONE
    100 #include <stdio.h>
    101 #endif
    102 
    103 #include "extern.h"
    104 
    105 union dinode {
    106 	struct ufs1_dinode dp1;
    107 	struct ufs2_dinode dp2;
    108 };
    109 
    110 static void initcg(int, const struct timeval *);
    111 static int fsinit(const struct timeval *, mode_t, uid_t, gid_t);
    112 static int makedir(struct direct *, int);
    113 static daddr_t alloc(int, int);
    114 static void iput(union dinode *, ino_t);
    115 static void rdfs(daddr_t, int, void *);
    116 static void wtfs(daddr_t, int, void *);
    117 static int isblock(struct fs *, unsigned char *, int);
    118 static void clrblock(struct fs *, unsigned char *, int);
    119 static void setblock(struct fs *, unsigned char *, int);
    120 static int ilog2(int);
    121 static void zap_old_sblock(int);
    122 #ifdef MFS
    123 static void calc_memfree(void);
    124 static void *mkfs_malloc(size_t size);
    125 #endif
    126 
    127 /*
    128  * make file system for cylinder-group style file systems
    129  */
    130 #define	UMASK		0755
    131 
    132 union {
    133 	struct fs fs;
    134 	char pad[SBLOCKSIZE];
    135 } fsun;
    136 #define	sblock	fsun.fs
    137 
    138 struct	csum *fscs_0;		/* first block of cylinder summaries */
    139 struct	csum *fscs_next;	/* place for next summary */
    140 struct	csum *fscs_end;		/* end of summary buffer */
    141 struct	csum *fscs_reset;	/* place for next summary after write */
    142 uint	fs_csaddr;		/* fragment number to write to */
    143 
    144 union {
    145 	struct cg cg;
    146 	char pad[MAXBSIZE];
    147 } cgun;
    148 #define	acg	cgun.cg
    149 
    150 #define DIP(dp, field) \
    151 	((sblock.fs_magic == FS_UFS1_MAGIC) ? \
    152 	(dp)->dp1.di_##field : (dp)->dp2.di_##field)
    153 
    154 char *iobuf;
    155 int iobufsize;			/* size to end of 2nd inode block */
    156 int iobuf_memsize;		/* Actual buffer size */
    157 
    158 int	fsi, fso;
    159 
    160 void
    161 mkfs(const char *fsys, int fi, int fo,
    162     mode_t mfsmode, uid_t mfsuid, gid_t mfsgid)
    163 {
    164 	uint fragsperinodeblk, ncg, u;
    165 	uint cgzero;
    166 	uint64_t inodeblks, cgall;
    167 	int32_t cylno, i, csfrags;
    168 	int inodes_per_cg;
    169 	struct timeval tv;
    170 	long long sizepb;
    171 	int len, col, delta, fld_width, max_cols;
    172 	struct winsize winsize;
    173 
    174 #ifndef STANDALONE
    175 	gettimeofday(&tv, NULL);
    176 #endif
    177 #ifdef MFS
    178 	if (mfs && !Nflag) {
    179 		calc_memfree();
    180 		if ((uint64_t)fssize * sectorsize > memleft)
    181 			fssize = memleft / sectorsize;
    182 		if ((membase = mkfs_malloc(fssize * sectorsize)) == NULL)
    183 			exit(12);
    184 	}
    185 #endif
    186 	fsi = fi;
    187 	fso = fo;
    188 	if (Oflag == 0) {
    189 		sblock.fs_old_inodefmt = FS_42INODEFMT;
    190 		sblock.fs_maxsymlinklen = 0;
    191 		sblock.fs_old_flags = 0;
    192 	} else {
    193 		sblock.fs_old_inodefmt = FS_44INODEFMT;
    194 		sblock.fs_maxsymlinklen = (Oflag == 1 ? MAXSYMLINKLEN_UFS1 :
    195 		    MAXSYMLINKLEN_UFS2);
    196 		sblock.fs_old_flags = FS_FLAGS_UPDATED;
    197 		if (isappleufs)
    198 			sblock.fs_old_flags = 0;
    199 		sblock.fs_flags = 0;
    200 	}
    201 
    202 	/*
    203 	 * collect and verify the filesystem density info
    204 	 */
    205 	sblock.fs_avgfilesize = avgfilesize;
    206 	sblock.fs_avgfpdir = avgfpdir;
    207 	if (sblock.fs_avgfilesize <= 0) {
    208 		printf("illegal expected average file size %d\n",
    209 		    sblock.fs_avgfilesize);
    210 		exit(14);
    211 	}
    212 	if (sblock.fs_avgfpdir <= 0) {
    213 		printf("illegal expected number of files per directory %d\n",
    214 		    sblock.fs_avgfpdir);
    215 		exit(15);
    216 	}
    217 	/*
    218 	 * collect and verify the block and fragment sizes
    219 	 */
    220 	sblock.fs_bsize = bsize;
    221 	sblock.fs_fsize = fsize;
    222 	if (!powerof2(sblock.fs_bsize)) {
    223 		printf("block size must be a power of 2, not %d\n",
    224 		    sblock.fs_bsize);
    225 		exit(16);
    226 	}
    227 	if (!powerof2(sblock.fs_fsize)) {
    228 		printf("fragment size must be a power of 2, not %d\n",
    229 		    sblock.fs_fsize);
    230 		exit(17);
    231 	}
    232 	if (sblock.fs_fsize < sectorsize) {
    233 		printf("fragment size %d is too small, minimum is %d\n",
    234 		    sblock.fs_fsize, sectorsize);
    235 		exit(18);
    236 	}
    237 	if (sblock.fs_bsize < MINBSIZE) {
    238 		printf("block size %d is too small, minimum is %d\n",
    239 		    sblock.fs_bsize, MINBSIZE);
    240 		exit(19);
    241 	}
    242 	if (sblock.fs_bsize > MAXBSIZE) {
    243 		printf("block size %d is too large, maximum is %d\n",
    244 		    sblock.fs_bsize, MAXBSIZE);
    245 		exit(19);
    246 	}
    247 	if (sblock.fs_bsize < sblock.fs_fsize) {
    248 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
    249 		    sblock.fs_bsize, sblock.fs_fsize);
    250 		exit(20);
    251 	}
    252 
    253 	if (maxbsize < bsize || !powerof2(maxbsize)) {
    254 		sblock.fs_maxbsize = sblock.fs_bsize;
    255 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
    256 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
    257 	} else {
    258 		sblock.fs_maxbsize = maxbsize;
    259 	}
    260 	sblock.fs_maxcontig = maxcontig;
    261 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
    262 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
    263 		if (verbosity > 0)
    264 			printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
    265 	}
    266 	if (sblock.fs_maxcontig > 1)
    267 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
    268 
    269 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
    270 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
    271 	sblock.fs_qbmask = ~sblock.fs_bmask;
    272 	sblock.fs_qfmask = ~sblock.fs_fmask;
    273 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
    274 		sblock.fs_bshift++;
    275 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
    276 		sblock.fs_fshift++;
    277 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
    278 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
    279 		sblock.fs_fragshift++;
    280 	if (sblock.fs_frag > MAXFRAG) {
    281 		printf("fragment size %d is too small, "
    282 			"minimum with block size %d is %d\n",
    283 		    sblock.fs_fsize, sblock.fs_bsize,
    284 		    sblock.fs_bsize / MAXFRAG);
    285 		exit(21);
    286 	}
    287 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
    288 	sblock.fs_size = dbtofsb(&sblock, fssize);
    289 	if (Oflag <= 1) {
    290 		if ((uint64_t)sblock.fs_size >= 1ull << 31) {
    291 			printf("Too many fragments (0x%" PRIx64
    292 			    ") for a FFSv1 filesystem\n", sblock.fs_size);
    293 			exit(22);
    294 		}
    295 		sblock.fs_magic = FS_UFS1_MAGIC;
    296 		sblock.fs_sblockloc = SBLOCK_UFS1;
    297 		sblock.fs_nindir = sblock.fs_bsize / sizeof(int32_t);
    298 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
    299 		sblock.fs_old_cgoffset = 0;
    300 		sblock.fs_old_cgmask = 0xffffffff;
    301 		sblock.fs_old_size = sblock.fs_size;
    302 		sblock.fs_old_rotdelay = 0;
    303 		sblock.fs_old_rps = 60;
    304 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
    305 		sblock.fs_old_cpg = 1;
    306 		sblock.fs_old_interleave = 1;
    307 		sblock.fs_old_trackskew = 0;
    308 		sblock.fs_old_cpc = 0;
    309 		sblock.fs_old_postblformat = FS_DYNAMICPOSTBLFMT;
    310 		sblock.fs_old_nrpos = 1;
    311 	} else {
    312 		sblock.fs_magic = FS_UFS2_MAGIC;
    313 		sblock.fs_sblockloc = SBLOCK_UFS2;
    314 		sblock.fs_nindir = sblock.fs_bsize / sizeof(int64_t);
    315 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
    316 	}
    317 
    318 	sblock.fs_sblkno =
    319 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
    320 		sblock.fs_frag);
    321 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
    322 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag));
    323 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
    324 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
    325 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
    326 		sizepb *= NINDIR(&sblock);
    327 		sblock.fs_maxfilesize += sizepb;
    328 	}
    329 
    330 	/*
    331 	 * Calculate the number of blocks to put into each cylinder group.
    332 	 *
    333 	 * The cylinder group size is limited because the data structure
    334 	 * must fit into a single block.
    335 	 * We try to have as few cylinder groups as possible, with a proviso
    336 	 * that we create at least MINCYLGRPS (==4) except for small
    337 	 * filesystems.
    338 	 *
    339 	 * This algorithm works out how many blocks of inodes would be
    340 	 * needed to fill the entire volume at the specified density.
    341 	 * It then looks at how big the 'cylinder block' would have to
    342 	 * be and, assuming that it is linearly related to the number
    343 	 * of inodes and blocks how many cylinder groups are needed to
    344 	 * keep the cylinder block below the filesystem block size.
    345 	 *
    346 	 * The cylinder groups are then all created with the average size.
    347 	 *
    348 	 * Space taken by the red tape on cylinder groups other than the
    349 	 * first is ignored.
    350 	 */
    351 
    352 	/* There must be space for 1 inode block and 2 data blocks */
    353 	if (sblock.fs_size < sblock.fs_iblkno + 3 * sblock.fs_frag) {
    354 		printf("Filesystem size %lld < minimum size of %d\n",
    355 		    (long long)sblock.fs_size, sblock.fs_iblkno + 3 * sblock.fs_frag);
    356 		exit(23);
    357 	}
    358 	if (num_inodes != 0)
    359 		inodeblks = howmany(num_inodes, INOPB(&sblock));
    360 	else {
    361 		/*
    362 		 * Calculate 'per inode block' so we can allocate less than
    363 		 * 1 fragment per inode - useful for /dev.
    364 		 */
    365 		fragsperinodeblk = MAX(numfrags(&sblock,
    366 					(uint64_t)density * INOPB(&sblock)), 1);
    367 		inodeblks = (sblock.fs_size - sblock.fs_iblkno) /
    368 			(sblock.fs_frag + fragsperinodeblk);
    369 	}
    370 	if (inodeblks == 0)
    371 		inodeblks = 1;
    372 	/* Ensure that there are at least 2 data blocks (or we fail below) */
    373 	if (inodeblks > (uint64_t)(sblock.fs_size - sblock.fs_iblkno)/sblock.fs_frag - 2)
    374 		inodeblks = (sblock.fs_size-sblock.fs_iblkno)/sblock.fs_frag-2;
    375 	/* Even UFS2 limits number of inodes to 2^31 (fs_ipg is int32_t) */
    376 	if (inodeblks * INOPB(&sblock) >= 1ull << 31)
    377 		inodeblks = ((1ull << 31) - NBBY) / INOPB(&sblock);
    378 	/*
    379 	 * See what would happen if we tried to use 1 cylinder group.
    380 	 * Assume space linear, so work out number of cylinder groups needed.
    381 	 */
    382 	cgzero = CGSIZE_IF(&sblock, 0, 0);
    383 	cgall = CGSIZE_IF(&sblock, inodeblks * INOPB(&sblock), sblock.fs_size);
    384 	ncg = howmany(cgall - cgzero, sblock.fs_bsize - cgzero);
    385 	if (ncg < MINCYLGRPS) {
    386 		/*
    387 		 * We would like to allocate MINCLYGRPS cylinder groups,
    388 		 * but for small file sytems (especially ones with a lot
    389 		 * of inodes) this is not desirable (or possible).
    390 		 */
    391 		u = sblock.fs_size / 2 / (sblock.fs_iblkno +
    392 						inodeblks * sblock.fs_frag);
    393 		if (u > ncg)
    394 			ncg = u;
    395 		if (ncg > MINCYLGRPS)
    396 			ncg = MINCYLGRPS;
    397 		if (ncg > inodeblks)
    398 			ncg = inodeblks;
    399 	}
    400 	/*
    401 	 * Put an equal number of blocks in each cylinder group.
    402 	 * Round up so we don't have more fragments in the last CG than
    403 	 * the earlier ones (does that matter?), but kill a block if the
    404 	 * CGSIZE becomes too big (only happens if there are a lot of CGs).
    405 	 */
    406 	sblock.fs_fpg = roundup(howmany(sblock.fs_size, ncg), sblock.fs_frag);
    407 	/* Round up the fragments/group so the bitmap bytes are full */
    408 	sblock.fs_fpg = roundup(sblock.fs_fpg, NBBY);
    409 	inodes_per_cg = ((inodeblks - 1) / ncg + 1) * INOPB(&sblock);
    410 
    411 	i = CGSIZE_IF(&sblock, inodes_per_cg, sblock.fs_fpg);
    412 	if (i > sblock.fs_bsize) {
    413 		sblock.fs_fpg -= (i - sblock.fs_bsize) * NBBY;
    414 		/* ... and recalculate how many cylinder groups we now need */
    415 		ncg = howmany(sblock.fs_size, sblock.fs_fpg);
    416 		inodes_per_cg = ((inodeblks - 1) / ncg + 1) * INOPB(&sblock);
    417 	}
    418 	sblock.fs_ipg = inodes_per_cg;
    419 	/* Sanity check on our sums... */
    420 	if ((int)CGSIZE(&sblock) > sblock.fs_bsize) {
    421 		printf("CGSIZE miscalculated %d > %d\n",
    422 		    (int)CGSIZE(&sblock), sblock.fs_bsize);
    423 		exit(24);
    424 	}
    425 
    426 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
    427 	/* Check that the last cylinder group has enough space for the inodes */
    428 	i = sblock.fs_size - sblock.fs_fpg * (ncg - 1ull);
    429 	if (i < sblock.fs_dblkno) {
    430 		/*
    431 		 * Since we make all the cylinder groups the same size, the
    432 		 * last will only be small if there are a large number of
    433 		 * cylinder groups. If we pull even a fragment from each
    434 		 * of the other groups then the last CG will be overfull.
    435 		 * So we just kill the last CG.
    436 		 */
    437 		ncg--;
    438 		sblock.fs_size -= i;
    439 	}
    440 	sblock.fs_ncg = ncg;
    441 
    442 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
    443 	if (Oflag <= 1) {
    444 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
    445 		sblock.fs_old_nsect = sblock.fs_old_spc;
    446 		sblock.fs_old_npsect = sblock.fs_old_spc;
    447 		sblock.fs_old_ncyl = sblock.fs_ncg;
    448 	}
    449 
    450 	/*
    451 	 * Cylinder group summary information for each cylinder is written
    452 	 * into the first cylinder group.
    453 	 * Write this fragment by fragment, but doing the first CG last
    454 	 * (after we've taken stuff off for the structure itself and the
    455 	 * root directory.
    456 	 */
    457 	sblock.fs_csaddr = cgdmin(&sblock, 0);
    458 	sblock.fs_cssize =
    459 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
    460 	if (512 % sizeof *fscs_0)
    461 		errx(1, "cylinder group summary doesn't fit in sectors");
    462 	fscs_0 = mmap(0, 2 * sblock.fs_fsize, PROT_READ|PROT_WRITE,
    463 			MAP_ANON|MAP_PRIVATE, -1, 0);
    464 	if (fscs_0 == MAP_FAILED)
    465 		exit(39);
    466 	memset(fscs_0, 0, 2 * sblock.fs_fsize);
    467 	fs_csaddr = sblock.fs_csaddr;
    468 	fscs_next = fscs_0;
    469 	fscs_end = (void *)((char *)fscs_0 + 2 * sblock.fs_fsize);
    470 	fscs_reset = (void *)((char *)fscs_0 + sblock.fs_fsize);
    471 	/*
    472 	 * fill in remaining fields of the super block
    473 	 */
    474 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
    475 	if (sblock.fs_sbsize > SBLOCKSIZE)
    476 		sblock.fs_sbsize = SBLOCKSIZE;
    477 	sblock.fs_minfree = minfree;
    478 	sblock.fs_maxcontig = maxcontig;
    479 	sblock.fs_maxbpg = maxbpg;
    480 	sblock.fs_optim = opt;
    481 	sblock.fs_cgrotor = 0;
    482 	sblock.fs_pendingblocks = 0;
    483 	sblock.fs_pendinginodes = 0;
    484 	sblock.fs_cstotal.cs_ndir = 0;
    485 	sblock.fs_cstotal.cs_nbfree = 0;
    486 	sblock.fs_cstotal.cs_nifree = 0;
    487 	sblock.fs_cstotal.cs_nffree = 0;
    488 	sblock.fs_fmod = 0;
    489 	sblock.fs_ronly = 0;
    490 	sblock.fs_state = 0;
    491 	sblock.fs_clean = FS_ISCLEAN;
    492 	sblock.fs_ronly = 0;
    493 	sblock.fs_id[0] = (long)tv.tv_sec;	/* XXXfvdl huh? */
    494 	sblock.fs_id[1] = arc4random() & INT32_MAX;
    495 	sblock.fs_fsmnt[0] = '\0';
    496 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
    497 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
    498 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
    499 	sblock.fs_cstotal.cs_nbfree =
    500 	    fragstoblks(&sblock, sblock.fs_dsize) -
    501 	    howmany(csfrags, sblock.fs_frag);
    502 	sblock.fs_cstotal.cs_nffree =
    503 	    fragnum(&sblock, sblock.fs_size) +
    504 	    (fragnum(&sblock, csfrags) > 0 ?
    505 	    sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
    506 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
    507 	sblock.fs_cstotal.cs_ndir = 0;
    508 	sblock.fs_dsize -= csfrags;
    509 	sblock.fs_time = tv.tv_sec;
    510 	if (Oflag <= 1) {
    511 		sblock.fs_old_time = tv.tv_sec;
    512 		sblock.fs_old_dsize = sblock.fs_dsize;
    513 		sblock.fs_old_csaddr = sblock.fs_csaddr;
    514 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
    515 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
    516 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
    517 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
    518 	}
    519 	/*
    520 	 * Dump out summary information about file system.
    521 	 */
    522 	if (verbosity > 0) {
    523 #define	B2MBFACTOR (1 / (1024.0 * 1024.0))
    524 		printf("%s: %.1fMB (%lld sectors) block size %d, "
    525 		       "fragment size %d\n",
    526 		    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
    527 		    (long long)fsbtodb(&sblock, sblock.fs_size),
    528 		    sblock.fs_bsize, sblock.fs_fsize);
    529 		printf("\tusing %d cylinder groups of %.2fMB, %d blks, "
    530 		       "%d inodes.\n",
    531 		    sblock.fs_ncg,
    532 		    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
    533 		    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
    534 #undef B2MBFACTOR
    535 	}
    536 
    537 	/*
    538 	 * allocate space for superblock, cylinder group map, and
    539 	 * two sets of inode blocks.
    540 	 */
    541 	if (sblock.fs_bsize < SBLOCKSIZE)
    542 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
    543 	else
    544 		iobufsize = 4 * sblock.fs_bsize;
    545 	iobuf_memsize = iobufsize;
    546 	if (!mfs && sblock.fs_magic == FS_UFS1_MAGIC) {
    547 		/* A larger buffer so we can write multiple inode blks */
    548 		iobuf_memsize += 14 * sblock.fs_bsize;
    549 	}
    550 	for (;;) {
    551 		iobuf = mmap(0, iobuf_memsize, PROT_READ|PROT_WRITE,
    552 				MAP_ANON|MAP_PRIVATE, -1, 0);
    553 		if (iobuf != MAP_FAILED)
    554 			break;
    555 		if (iobuf_memsize != iobufsize) {
    556 			/* Try again with the smaller size */
    557 			iobuf_memsize = iobufsize;
    558 			continue;
    559 		}
    560 		printf("Cannot allocate I/O buffer\n");
    561 		exit(38);
    562 	}
    563 	memset(iobuf, 0, iobuf_memsize);
    564 
    565 	/*
    566 	 * We now start writing to the filesystem
    567 	 */
    568 
    569 	if (!Nflag) {
    570 		/*
    571 		 * Validate the given file system size.
    572 		 * Verify that its last block can actually be accessed.
    573 		 * Convert to file system fragment sized units.
    574 		 */
    575 		if (fssize <= 0) {
    576 			printf("preposterous size %lld\n", (long long)fssize);
    577 			exit(13);
    578 		}
    579 		wtfs(fssize - 1, sectorsize, iobuf);
    580 
    581 		/*
    582 		 * Ensure there is nothing that looks like a filesystem
    583 		 * superbock anywhere other than where ours will be.
    584 		 * If fsck finds the wrong one all hell breaks loose!
    585 		 */
    586 		for (i = 0; ; i++) {
    587 			static const int sblocklist[] = SBLOCKSEARCH;
    588 			int sblkoff = sblocklist[i];
    589 			int sz;
    590 			if (sblkoff == -1)
    591 				break;
    592 			/* Remove main superblock */
    593 			zap_old_sblock(sblkoff);
    594 			/* and all possible locations for the first alternate */
    595 			sblkoff += SBLOCKSIZE;
    596 			for (sz = SBLOCKSIZE; sz <= 0x10000; sz <<= 1)
    597 				zap_old_sblock(roundup(sblkoff, sz));
    598 		}
    599 
    600 		if (isappleufs) {
    601 			struct appleufslabel appleufs;
    602 			ffs_appleufs_set(&appleufs, appleufs_volname,
    603 			    tv.tv_sec, 0);
    604 			wtfs(APPLEUFS_LABEL_OFFSET/sectorsize,
    605 			    APPLEUFS_LABEL_SIZE, &appleufs);
    606 		} else if (APPLEUFS_LABEL_SIZE % sectorsize == 0) {
    607 			struct appleufslabel appleufs;
    608 			/* Look for & zap any existing valid apple ufs labels */
    609 			rdfs(APPLEUFS_LABEL_OFFSET/sectorsize,
    610 			    APPLEUFS_LABEL_SIZE, &appleufs);
    611 			if (ffs_appleufs_validate(fsys, &appleufs, NULL) == 0) {
    612 				memset(&appleufs, 0, sizeof(appleufs));
    613 				wtfs(APPLEUFS_LABEL_OFFSET/sectorsize,
    614 				    APPLEUFS_LABEL_SIZE, &appleufs);
    615 			}
    616 		}
    617 	}
    618 
    619 	/*
    620 	 * Make a copy of the superblock into the buffer that we will be
    621 	 * writing out in each cylinder group.
    622 	 */
    623 	memcpy(iobuf, &sblock, sizeof sblock);
    624 	if (needswap)
    625 		ffs_sb_swap(&sblock, (struct fs *)iobuf);
    626 	if ((sblock.fs_old_flags & FS_FLAGS_UPDATED) == 0)
    627 		memset(iobuf + offsetof(struct fs, fs_old_postbl_start),
    628 		    0xff, 256);
    629 
    630 	if (verbosity >= 3)
    631 		printf("super-block backups (for fsck_ffs -b #) at:\n");
    632 	/* If we are printing more than one line of numbers, line up columns */
    633 	fld_width = verbosity < 4 ? 1 : snprintf(NULL, 0, "%" PRIu64,
    634 		(uint64_t)fsbtodb(&sblock, cgsblock(&sblock, sblock.fs_ncg-1)));
    635 	/* Get terminal width */
    636 	if (ioctl(fileno(stdout), TIOCGWINSZ, &winsize) == 0)
    637 		max_cols = winsize.ws_col;
    638 	else
    639 		max_cols = 80;
    640 	if (Nflag && verbosity == 3)
    641 		/* Leave space to add " ..." after one row of numbers */
    642 		max_cols -= 4;
    643 #define BASE 0x10000	/* For some fixed-point maths */
    644 	col = 0;
    645 	delta = verbosity > 2 ? 0 : max_cols * BASE / sblock.fs_ncg;
    646 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
    647 		fflush(stdout);
    648 		initcg(cylno, &tv);
    649 		if (verbosity < 2)
    650 			continue;
    651 		if (delta > 0) {
    652 			if (Nflag)
    653 				/* No point doing dots for -N */
    654 				break;
    655 			/* Print dots scaled to end near RH margin */
    656 			for (col += delta; col > BASE; col -= BASE)
    657 				printf(".");
    658 			continue;
    659 		}
    660 		/* Print superblock numbers */
    661 		len = printf(" %*" PRIu64 "," + !col, fld_width,
    662 		    (uint64_t)fsbtodb(&sblock, cgsblock(&sblock, cylno)));
    663 		col += len;
    664 		if (col + len < max_cols)
    665 			/* Next number fits */
    666 			continue;
    667 		/* Next number won't fit, need a newline */
    668 		if (verbosity <= 3) {
    669 			/* Print dots for subsequent cylinder groups */
    670 			delta = sblock.fs_ncg - cylno - 1;
    671 			if (delta != 0) {
    672 				if (Nflag) {
    673 					printf(" ...");
    674 					break;
    675 				}
    676 				delta = max_cols * BASE / delta;
    677 			}
    678 		}
    679 		col = 0;
    680 		printf("\n");
    681 	}
    682 #undef BASE
    683 	if (col > 0)
    684 		printf("\n");
    685 	if (Nflag)
    686 		exit(0);
    687 
    688 	/*
    689 	 * Now construct the initial file system,
    690 	 */
    691 	if (fsinit(&tv, mfsmode, mfsuid, mfsgid) == 0 && mfs)
    692 		errx(1, "Error making filesystem");
    693 	sblock.fs_time = tv.tv_sec;
    694 	if (Oflag <= 1) {
    695 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
    696 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
    697 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
    698 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
    699 	}
    700 	/*
    701 	 * Write out the super-block and zeros until the first cg info
    702 	 */
    703 	i = cgsblock(&sblock, 0) * sblock.fs_fsize - sblock.fs_sblockloc,
    704 	memset(iobuf, 0, i);
    705 	memcpy(iobuf, &sblock, sizeof sblock);
    706 	if (needswap)
    707 		ffs_sb_swap(&sblock, (struct fs *)iobuf);
    708 	if ((sblock.fs_old_flags & FS_FLAGS_UPDATED) == 0)
    709 		memset(iobuf + offsetof(struct fs, fs_old_postbl_start),
    710 		    0xff, 256);
    711 	wtfs(sblock.fs_sblockloc / sectorsize, i, iobuf);
    712 
    713 	/* Write out first and last cylinder summary sectors */
    714 	if (needswap)
    715 		ffs_csum_swap(fscs_0, fscs_0, sblock.fs_fsize);
    716 	wtfs(fsbtodb(&sblock, sblock.fs_csaddr), sblock.fs_fsize, fscs_0);
    717 
    718 	if (fscs_next > fscs_reset) {
    719 		if (needswap)
    720 			ffs_csum_swap(fscs_reset, fscs_reset, sblock.fs_fsize);
    721 		fs_csaddr++;
    722 		wtfs(fsbtodb(&sblock, fs_csaddr), sblock.fs_fsize, fscs_reset);
    723 	}
    724 
    725 	/* mfs doesn't need these permanently allocated */
    726 	munmap(iobuf, iobuf_memsize);
    727 	munmap(fscs_0, 2 * sblock.fs_fsize);
    728 }
    729 
    730 /*
    731  * Initialize a cylinder group.
    732  */
    733 void
    734 initcg(int cylno, const struct timeval *tv)
    735 {
    736 	daddr_t cbase, dmax;
    737 	int32_t i, d, dlower, dupper, blkno;
    738 	uint32_t u;
    739 	struct ufs1_dinode *dp1;
    740 	struct ufs2_dinode *dp2;
    741 	int start;
    742 
    743 	/*
    744 	 * Determine block bounds for cylinder group.
    745 	 * Allow space for super block summary information in first
    746 	 * cylinder group.
    747 	 */
    748 	cbase = cgbase(&sblock, cylno);
    749 	dmax = cbase + sblock.fs_fpg;
    750 	if (dmax > sblock.fs_size)
    751 		dmax = sblock.fs_size;
    752 	dlower = cgsblock(&sblock, cylno) - cbase;
    753 	dupper = cgdmin(&sblock, cylno) - cbase;
    754 	if (cylno == 0) {
    755 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
    756 		if (dupper >= cgstart(&sblock, cylno + 1)) {
    757 			printf("\rToo many cylinder groups to fit summary "
    758 				"information into first cylinder group\n");
    759 			exit(40);
    760 		}
    761 	}
    762 	memset(&acg, 0, sblock.fs_cgsize);
    763 	acg.cg_magic = CG_MAGIC;
    764 	acg.cg_cgx = cylno;
    765 	acg.cg_ndblk = dmax - cbase;
    766 	if (sblock.fs_contigsumsize > 0)
    767 		acg.cg_nclusterblks = acg.cg_ndblk >> sblock.fs_fragshift;
    768 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
    769 	if (Oflag == 2) {
    770 		acg.cg_time = tv->tv_sec;
    771 		acg.cg_niblk = sblock.fs_ipg;
    772 		acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
    773 		    sblock.fs_ipg : 2 * INOPB(&sblock);
    774 		acg.cg_iusedoff = start;
    775 	} else {
    776 		acg.cg_old_ncyl = sblock.fs_old_cpg;
    777 		if ((sblock.fs_old_flags & FS_FLAGS_UPDATED) == 0 &&
    778 		    (cylno == sblock.fs_ncg - 1))
    779 			acg.cg_old_ncyl =
    780 			    sblock.fs_old_ncyl % sblock.fs_old_cpg;
    781 		acg.cg_old_time = tv->tv_sec;
    782 		acg.cg_old_niblk = sblock.fs_ipg;
    783 		acg.cg_old_btotoff = start;
    784 		acg.cg_old_boff = acg.cg_old_btotoff +
    785 		    sblock.fs_old_cpg * sizeof(int32_t);
    786 		acg.cg_iusedoff = acg.cg_old_boff +
    787 		    sblock.fs_old_cpg * sizeof(u_int16_t);
    788 	}
    789 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
    790 	if (sblock.fs_contigsumsize <= 0) {
    791 		acg.cg_nextfreeoff = acg.cg_freeoff +
    792 		   howmany(sblock.fs_fpg, CHAR_BIT);
    793 	} else {
    794 		acg.cg_clustersumoff = acg.cg_freeoff +
    795 		    howmany(sblock.fs_fpg, CHAR_BIT) - sizeof(int32_t);
    796 		if (isappleufs) {
    797 			/* Apple PR2216969 gives rationale for this change.
    798 			 * I believe they were mistaken, but we need to
    799 			 * duplicate it for compatibility.  -- dbj (at) NetBSD.org
    800 			 */
    801 			acg.cg_clustersumoff += sizeof(int32_t);
    802 		}
    803 		acg.cg_clustersumoff =
    804 		    roundup(acg.cg_clustersumoff, sizeof(int32_t));
    805 		acg.cg_clusteroff = acg.cg_clustersumoff +
    806 		    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
    807 		acg.cg_nextfreeoff = acg.cg_clusteroff +
    808 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
    809 	}
    810 	if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
    811 		printf("Panic: cylinder group too big\n");
    812 		exit(37);
    813 	}
    814 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
    815 	if (cylno == 0)
    816 		for (u = 0; u < ROOTINO; u++) {
    817 			setbit(cg_inosused(&acg, 0), u);
    818 			acg.cg_cs.cs_nifree--;
    819 		}
    820 	if (cylno > 0) {
    821 		/*
    822 		 * In cylno 0, beginning space is reserved
    823 		 * for boot and super blocks.
    824 		 */
    825 		for (d = 0, blkno = 0; d < dlower;) {
    826 			setblock(&sblock, cg_blksfree(&acg, 0), blkno);
    827 			if (sblock.fs_contigsumsize > 0)
    828 				setbit(cg_clustersfree(&acg, 0), blkno);
    829 			acg.cg_cs.cs_nbfree++;
    830 			if (Oflag <= 1) {
    831 				int cn = old_cbtocylno(&sblock, d);
    832 				old_cg_blktot(&acg, 0)[cn]++;
    833 				old_cg_blks(&sblock, &acg,
    834 				    cn, 0)[old_cbtorpos(&sblock, d)]++;
    835 			}
    836 			d += sblock.fs_frag;
    837 			blkno++;
    838 		}
    839 	}
    840 	if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
    841 		acg.cg_frsum[sblock.fs_frag - i]++;
    842 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
    843 			setbit(cg_blksfree(&acg, 0), dupper);
    844 			acg.cg_cs.cs_nffree++;
    845 		}
    846 	}
    847 	for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
    848 	     d + sblock.fs_frag <= acg.cg_ndblk; ) {
    849 		setblock(&sblock, cg_blksfree(&acg, 0), blkno);
    850 		if (sblock.fs_contigsumsize > 0)
    851 			setbit(cg_clustersfree(&acg, 0), blkno);
    852 		acg.cg_cs.cs_nbfree++;
    853 		if (Oflag <= 1) {
    854 			int cn = old_cbtocylno(&sblock, d);
    855 			old_cg_blktot(&acg, 0)[cn]++;
    856 			old_cg_blks(&sblock, &acg,
    857 			    cn, 0)[old_cbtorpos(&sblock, d)]++;
    858 		}
    859 		d += sblock.fs_frag;
    860 		blkno++;
    861 	}
    862 	if (d < acg.cg_ndblk) {
    863 		acg.cg_frsum[acg.cg_ndblk - d]++;
    864 		for (; d < acg.cg_ndblk; d++) {
    865 			setbit(cg_blksfree(&acg, 0), d);
    866 			acg.cg_cs.cs_nffree++;
    867 		}
    868 	}
    869 	if (sblock.fs_contigsumsize > 0) {
    870 		int32_t *sump = cg_clustersum(&acg, 0);
    871 		u_char *mapp = cg_clustersfree(&acg, 0);
    872 		int map = *mapp++;
    873 		int bit = 1;
    874 		int run = 0;
    875 
    876 		for (i = 0; i < acg.cg_nclusterblks; i++) {
    877 			if ((map & bit) != 0) {
    878 				run++;
    879 			} else if (run != 0) {
    880 				if (run > sblock.fs_contigsumsize)
    881 					run = sblock.fs_contigsumsize;
    882 				sump[run]++;
    883 				run = 0;
    884 			}
    885 			if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
    886 				bit <<= 1;
    887 			} else {
    888 				map = *mapp++;
    889 				bit = 1;
    890 			}
    891 		}
    892 		if (run != 0) {
    893 			if (run > sblock.fs_contigsumsize)
    894 				run = sblock.fs_contigsumsize;
    895 			sump[run]++;
    896 		}
    897 	}
    898 	*fscs_next++ = acg.cg_cs;
    899 	if (fscs_next == fscs_end) {
    900 		/* write block of cylinder group summary info into cyl 0 */
    901 		if (needswap)
    902 			ffs_csum_swap(fscs_reset, fscs_reset, sblock.fs_fsize);
    903 		fs_csaddr++;
    904 		wtfs(fsbtodb(&sblock, fs_csaddr), sblock.fs_fsize, fscs_reset);
    905 		fscs_next = fscs_reset;
    906 		memset(fscs_next, 0, sblock.fs_fsize);
    907 	}
    908 	/*
    909 	 * Write out the duplicate super block, the cylinder group map
    910 	 * and two blocks worth of inodes in a single write.
    911 	 */
    912 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
    913 	memcpy(&iobuf[start], &acg, sblock.fs_cgsize);
    914 	if (needswap)
    915 		ffs_cg_swap(&acg, (struct cg*)&iobuf[start], &sblock);
    916 	start += sblock.fs_bsize;
    917 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
    918 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
    919 	for (i = MIN(sblock.fs_ipg, 2) * INOPB(&sblock); i != 0; i--) {
    920 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
    921 			/* No need to swap, it'll stay random */
    922 			dp1->di_gen = arc4random() & INT32_MAX;
    923 			dp1++;
    924 		} else {
    925 			dp2->di_gen = arc4random() & INT32_MAX;
    926 			dp2++;
    927 		}
    928 	}
    929 	wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
    930 	/*
    931 	 * For the old file system, we have to initialize all the inodes.
    932 	 */
    933 	if (sblock.fs_magic != FS_UFS1_MAGIC)
    934 		return;
    935 
    936 	/* Write 'd' (usually 16 * fs_frag) file-system fragments at once */
    937 	d = (iobuf_memsize - start) / sblock.fs_bsize * sblock.fs_frag;
    938 	dupper = sblock.fs_ipg / INOPF(&sblock);
    939 	for (i = 2 * sblock.fs_frag; i < dupper; i += d) {
    940 		if (d > dupper - i)
    941 			d = dupper - i;
    942 		dp1 = (struct ufs1_dinode *)(&iobuf[start]);
    943 		do
    944 			dp1->di_gen = arc4random() & INT32_MAX;
    945 		while ((char *)++dp1 < &iobuf[iobuf_memsize]);
    946 		wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
    947 		    d * sblock.fs_bsize / sblock.fs_frag, &iobuf[start]);
    948 	}
    949 }
    950 
    951 /*
    952  * initialize the file system
    953  */
    954 
    955 #ifdef LOSTDIR
    956 #define	PREDEFDIR 3
    957 #else
    958 #define	PREDEFDIR 2
    959 #endif
    960 
    961 struct direct root_dir[] = {
    962 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
    963 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
    964 #ifdef LOSTDIR
    965 	{ LOSTFOUNDINO, sizeof(struct direct), DT_DIR, 10, "lost+found" },
    966 #endif
    967 };
    968 struct odirect {
    969 	u_int32_t d_ino;
    970 	u_int16_t d_reclen;
    971 	u_int16_t d_namlen;
    972 	u_char	d_name[FFS_MAXNAMLEN + 1];
    973 } oroot_dir[] = {
    974 	{ ROOTINO, sizeof(struct direct), 1, "." },
    975 	{ ROOTINO, sizeof(struct direct), 2, ".." },
    976 #ifdef LOSTDIR
    977 	{ LOSTFOUNDINO, sizeof(struct direct), 10, "lost+found" },
    978 #endif
    979 };
    980 #ifdef LOSTDIR
    981 struct direct lost_found_dir[] = {
    982 	{ LOSTFOUNDINO, sizeof(struct direct), DT_DIR, 1, "." },
    983 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
    984 	{ 0, DIRBLKSIZ, 0, 0, 0 },
    985 };
    986 struct odirect olost_found_dir[] = {
    987 	{ LOSTFOUNDINO, sizeof(struct direct), 1, "." },
    988 	{ ROOTINO, sizeof(struct direct), 2, ".." },
    989 	{ 0, DIRBLKSIZ, 0, 0 },
    990 };
    991 #endif
    992 char buf[MAXBSIZE];
    993 static void copy_dir(struct direct *, struct direct *);
    994 
    995 int
    996 fsinit(const struct timeval *tv, mode_t mfsmode, uid_t mfsuid, gid_t mfsgid)
    997 {
    998 	union dinode node;
    999 #ifdef LOSTDIR
   1000 	int i;
   1001 	int dirblksiz = DIRBLKSIZ;
   1002 	if (isappleufs)
   1003 		dirblksiz = APPLEUFS_DIRBLKSIZ;
   1004 #endif
   1005 
   1006 	/*
   1007 	 * initialize the node
   1008 	 */
   1009 
   1010 #ifdef LOSTDIR
   1011 	/*
   1012 	 * create the lost+found directory
   1013 	 */
   1014 	memset(&node, 0, sizeof(node));
   1015 	if (Oflag == 0) {
   1016 		(void)makedir((struct direct *)olost_found_dir, 2);
   1017 		for (i = dirblksiz; i < sblock.fs_bsize; i += dirblksiz)
   1018 			copy_dir((struct direct*)&olost_found_dir[2],
   1019 				(struct direct*)&buf[i]);
   1020 	} else {
   1021 		(void)makedir(lost_found_dir, 2);
   1022 		for (i = dirblksiz; i < sblock.fs_bsize; i += dirblksiz)
   1023 			copy_dir(&lost_found_dir[2], (struct direct*)&buf[i]);
   1024 	}
   1025 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
   1026 		node.dp1.di_atime = tv->tv_sec;
   1027 		node.dp1.di_atimensec = tv->tv_usec * 1000;
   1028 		node.dp1.di_mtime = tv->tv_sec;
   1029 		node.dp1.di_mtimensec = tv->tv_usec * 1000;
   1030 		node.dp1.di_ctime = tv->tv_sec;
   1031 		node.dp1.di_ctimensec = tv->tv_usec * 1000;
   1032 		node.dp1.di_mode = IFDIR | UMASK;
   1033 		node.dp1.di_nlink = 2;
   1034 		node.dp1.di_size = sblock.fs_bsize;
   1035 		node.dp1.di_db[0] = alloc(node.dp1.di_size, node.dp1.di_mode);
   1036 		if (node.dp1.di_db[0] == 0)
   1037 			return (0);
   1038 		node.dp1.di_blocks = btodb(fragroundup(&sblock,
   1039 		    node.dp1.di_size));
   1040 		node.dp1.di_uid = geteuid();
   1041 		node.dp1.di_gid = getegid();
   1042 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), node.dp1.di_size,
   1043 		    buf);
   1044 	} else {
   1045 		node.dp2.di_atime = tv->tv_sec;
   1046 		node.dp2.di_atimensec = tv->tv_usec * 1000;
   1047 		node.dp2.di_mtime = tv->tv_sec;
   1048 		node.dp2.di_mtimensec = tv->tv_usec * 1000;
   1049 		node.dp2.di_ctime = tv->tv_sec;
   1050 		node.dp2.di_ctimensec = tv->tv_usec * 1000;
   1051 		node.dp2.di_birthtime = tv->tv_sec;
   1052 		node.dp2.di_birthnsec = tv->tv_usec * 1000;
   1053 		node.dp2.di_mode = IFDIR | UMASK;
   1054 		node.dp2.di_nlink = 2;
   1055 		node.dp2.di_size = sblock.fs_bsize;
   1056 		node.dp2.di_db[0] = alloc(node.dp2.di_size, node.dp2.di_mode);
   1057 		if (node.dp2.di_db[0] == 0)
   1058 			return (0);
   1059 		node.dp2.di_blocks = btodb(fragroundup(&sblock,
   1060 		    node.dp2.di_size));
   1061 		node.dp2.di_uid = geteuid();
   1062 		node.dp2.di_gid = getegid();
   1063 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), node.dp2.di_size,
   1064 		    buf);
   1065 	}
   1066 	iput(&node, LOSTFOUNDINO);
   1067 #endif
   1068 	/*
   1069 	 * create the root directory
   1070 	 */
   1071 	memset(&node, 0, sizeof(node));
   1072 	if (Oflag <= 1) {
   1073 		if (mfs) {
   1074 			node.dp1.di_mode = IFDIR | mfsmode;
   1075 			node.dp1.di_uid = mfsuid;
   1076 			node.dp1.di_gid = mfsgid;
   1077 		} else {
   1078 			node.dp1.di_mode = IFDIR | UMASK;
   1079 			node.dp1.di_uid = geteuid();
   1080 			node.dp1.di_gid = getegid();
   1081 		}
   1082 		node.dp1.di_nlink = PREDEFDIR;
   1083 		if (Oflag == 0)
   1084 			node.dp1.di_size = makedir((struct direct *)oroot_dir,
   1085 			    PREDEFDIR);
   1086 		else
   1087 			node.dp1.di_size = makedir(root_dir, PREDEFDIR);
   1088 		node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
   1089 		if (node.dp1.di_db[0] == 0)
   1090 			return (0);
   1091 		node.dp1.di_blocks = btodb(fragroundup(&sblock,
   1092 		    node.dp1.di_size));
   1093 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize, buf);
   1094 	} else {
   1095 		if (mfs) {
   1096 			node.dp2.di_mode = IFDIR | mfsmode;
   1097 			node.dp2.di_uid = mfsuid;
   1098 			node.dp2.di_gid = mfsgid;
   1099 		} else {
   1100 			node.dp2.di_mode = IFDIR | UMASK;
   1101 			node.dp2.di_uid = geteuid();
   1102 			node.dp2.di_gid = getegid();
   1103 		}
   1104 		node.dp2.di_atime = tv->tv_sec;
   1105 		node.dp2.di_atimensec = tv->tv_usec * 1000;
   1106 		node.dp2.di_mtime = tv->tv_sec;
   1107 		node.dp2.di_mtimensec = tv->tv_usec * 1000;
   1108 		node.dp2.di_ctime = tv->tv_sec;
   1109 		node.dp2.di_ctimensec = tv->tv_usec * 1000;
   1110 		node.dp2.di_birthtime = tv->tv_sec;
   1111 		node.dp2.di_birthnsec = tv->tv_usec * 1000;
   1112 		node.dp2.di_nlink = PREDEFDIR;
   1113 		node.dp2.di_size = makedir(root_dir, PREDEFDIR);
   1114 		node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
   1115 		if (node.dp2.di_db[0] == 0)
   1116 			return (0);
   1117 		node.dp2.di_blocks = btodb(fragroundup(&sblock,
   1118 		    node.dp2.di_size));
   1119 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize, buf);
   1120 	}
   1121 	iput(&node, ROOTINO);
   1122 	return (1);
   1123 }
   1124 
   1125 /*
   1126  * construct a set of directory entries in "buf".
   1127  * return size of directory.
   1128  */
   1129 int
   1130 makedir(struct direct *protodir, int entries)
   1131 {
   1132 	char *cp;
   1133 	int i, spcleft;
   1134 	int dirblksiz = DIRBLKSIZ;
   1135 	if (isappleufs)
   1136 		dirblksiz = APPLEUFS_DIRBLKSIZ;
   1137 
   1138 	memset(buf, 0, DIRBLKSIZ);
   1139 	spcleft = dirblksiz;
   1140 	for (cp = buf, i = 0; i < entries - 1; i++) {
   1141 		protodir[i].d_reclen = DIRSIZ(Oflag == 0, &protodir[i], 0);
   1142 		copy_dir(&protodir[i], (struct direct*)cp);
   1143 		cp += protodir[i].d_reclen;
   1144 		spcleft -= protodir[i].d_reclen;
   1145 	}
   1146 	protodir[i].d_reclen = spcleft;
   1147 	copy_dir(&protodir[i], (struct direct*)cp);
   1148 	return (dirblksiz);
   1149 }
   1150 
   1151 /*
   1152  * allocate a block or frag
   1153  */
   1154 daddr_t
   1155 alloc(int size, int mode)
   1156 {
   1157 	int i, frag;
   1158 	daddr_t d, blkno;
   1159 
   1160 	rdfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize, &acg);
   1161 	/* fs -> host byte order */
   1162 	if (needswap)
   1163 		ffs_cg_swap(&acg, &acg, &sblock);
   1164 	if (acg.cg_magic != CG_MAGIC) {
   1165 		printf("cg 0: bad magic number\n");
   1166 		return (0);
   1167 	}
   1168 	if (acg.cg_cs.cs_nbfree == 0) {
   1169 		printf("first cylinder group ran out of space\n");
   1170 		return (0);
   1171 	}
   1172 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
   1173 		if (isblock(&sblock, cg_blksfree(&acg, 0),
   1174 		    d >> sblock.fs_fragshift))
   1175 			goto goth;
   1176 	printf("internal error: can't find block in cyl 0\n");
   1177 	return (0);
   1178 goth:
   1179 	blkno = fragstoblks(&sblock, d);
   1180 	clrblock(&sblock, cg_blksfree(&acg, 0), blkno);
   1181 	if (sblock.fs_contigsumsize > 0)
   1182 		clrbit(cg_clustersfree(&acg, 0), blkno);
   1183 	acg.cg_cs.cs_nbfree--;
   1184 	sblock.fs_cstotal.cs_nbfree--;
   1185 	fscs_0->cs_nbfree--;
   1186 	if (mode & IFDIR) {
   1187 		acg.cg_cs.cs_ndir++;
   1188 		sblock.fs_cstotal.cs_ndir++;
   1189 		fscs_0->cs_ndir++;
   1190 	}
   1191 	if (Oflag <= 1) {
   1192 		int cn = old_cbtocylno(&sblock, d);
   1193 		old_cg_blktot(&acg, 0)[cn]--;
   1194 		old_cg_blks(&sblock, &acg,
   1195 		    cn, 0)[old_cbtorpos(&sblock, d)]--;
   1196 	}
   1197 	if (size != sblock.fs_bsize) {
   1198 		frag = howmany(size, sblock.fs_fsize);
   1199 		fscs_0->cs_nffree += sblock.fs_frag - frag;
   1200 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
   1201 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
   1202 		acg.cg_frsum[sblock.fs_frag - frag]++;
   1203 		for (i = frag; i < sblock.fs_frag; i++)
   1204 			setbit(cg_blksfree(&acg, 0), d + i);
   1205 	}
   1206 	/* host -> fs byte order */
   1207 	if (needswap)
   1208 		ffs_cg_swap(&acg, &acg, &sblock);
   1209 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize, &acg);
   1210 	return (d);
   1211 }
   1212 
   1213 /*
   1214  * Allocate an inode on the disk
   1215  */
   1216 static void
   1217 iput(union dinode *ip, ino_t ino)
   1218 {
   1219 	daddr_t d;
   1220 	int c, i;
   1221 	struct ufs1_dinode *dp1;
   1222 	struct ufs2_dinode *dp2;
   1223 
   1224 	c = ino_to_cg(&sblock, ino);
   1225 	rdfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize, &acg);
   1226 	/* fs -> host byte order */
   1227 	if (needswap)
   1228 		ffs_cg_swap(&acg, &acg, &sblock);
   1229 	if (acg.cg_magic != CG_MAGIC) {
   1230 		printf("cg 0: bad magic number\n");
   1231 		exit(31);
   1232 	}
   1233 	acg.cg_cs.cs_nifree--;
   1234 	setbit(cg_inosused(&acg, 0), ino);
   1235 	/* host -> fs byte order */
   1236 	if (needswap)
   1237 		ffs_cg_swap(&acg, &acg, &sblock);
   1238 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize, &acg);
   1239 	sblock.fs_cstotal.cs_nifree--;
   1240 	fscs_0->cs_nifree--;
   1241 	if (ino >= (ino_t)(sblock.fs_ipg * sblock.fs_ncg)) {
   1242 		printf("fsinit: inode value out of range (%llu).\n",
   1243 		    (unsigned long long)ino);
   1244 		exit(32);
   1245 	}
   1246 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
   1247 	rdfs(d, sblock.fs_bsize, (char *)iobuf);
   1248 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
   1249 		dp1 = (struct ufs1_dinode *)iobuf;
   1250 		dp1 += ino_to_fsbo(&sblock, ino);
   1251 		if (needswap) {
   1252 			ffs_dinode1_swap(&ip->dp1, dp1);
   1253 			/* ffs_dinode1_swap() doesn't swap blocks addrs */
   1254 			for (i=0; i<NDADDR + NIADDR; i++)
   1255 			    dp1->di_db[i] = bswap32(ip->dp1.di_db[i]);
   1256 		} else
   1257 			*dp1 = ip->dp1;
   1258 		dp1->di_gen = arc4random() & INT32_MAX;
   1259 	} else {
   1260 		dp2 = (struct ufs2_dinode *)iobuf;
   1261 		dp2 += ino_to_fsbo(&sblock, ino);
   1262 		if (needswap) {
   1263 			ffs_dinode2_swap(&ip->dp2, dp2);
   1264 			for (i=0; i<NDADDR + NIADDR; i++)
   1265 			    dp2->di_db[i] = bswap64(ip->dp2.di_db[i]);
   1266 		} else
   1267 			*dp2 = ip->dp2;
   1268 		dp2->di_gen = arc4random() & INT32_MAX;
   1269 	}
   1270 	wtfs(d, sblock.fs_bsize, iobuf);
   1271 }
   1272 
   1273 /*
   1274  * read a block from the file system
   1275  */
   1276 void
   1277 rdfs(daddr_t bno, int size, void *bf)
   1278 {
   1279 	int n;
   1280 	off_t offset;
   1281 
   1282 #ifdef MFS
   1283 	if (mfs) {
   1284 		if (Nflag)
   1285 			memset(bf, 0, size);
   1286 		else
   1287 			memmove(bf, membase + bno * sectorsize, size);
   1288 		return;
   1289 	}
   1290 #endif
   1291 	offset = bno;
   1292 	n = pread(fsi, bf, size, offset * sectorsize);
   1293 	if (n != size) {
   1294 		printf("rdfs: read error for sector %lld: %s\n",
   1295 		    (long long)bno, strerror(errno));
   1296 		exit(34);
   1297 	}
   1298 }
   1299 
   1300 /*
   1301  * write a block to the file system
   1302  */
   1303 void
   1304 wtfs(daddr_t bno, int size, void *bf)
   1305 {
   1306 	int n;
   1307 	off_t offset;
   1308 
   1309 	if (Nflag)
   1310 		return;
   1311 #ifdef MFS
   1312 	if (mfs) {
   1313 		memmove(membase + bno * sectorsize, bf, size);
   1314 		return;
   1315 	}
   1316 #endif
   1317 	offset = bno;
   1318 	n = pwrite(fso, bf, size, offset * sectorsize);
   1319 	if (n != size) {
   1320 		printf("wtfs: write error for sector %lld: %s\n",
   1321 		    (long long)bno, strerror(errno));
   1322 		exit(36);
   1323 	}
   1324 }
   1325 
   1326 /*
   1327  * check if a block is available
   1328  */
   1329 int
   1330 isblock(struct fs *fs, unsigned char *cp, int h)
   1331 {
   1332 	unsigned char mask;
   1333 
   1334 	switch (fs->fs_fragshift) {
   1335 	case 3:
   1336 		return (cp[h] == 0xff);
   1337 	case 2:
   1338 		mask = 0x0f << ((h & 0x1) << 2);
   1339 		return ((cp[h >> 1] & mask) == mask);
   1340 	case 1:
   1341 		mask = 0x03 << ((h & 0x3) << 1);
   1342 		return ((cp[h >> 2] & mask) == mask);
   1343 	case 0:
   1344 		mask = 0x01 << (h & 0x7);
   1345 		return ((cp[h >> 3] & mask) == mask);
   1346 	default:
   1347 #ifdef STANDALONE
   1348 		printf("isblock bad fs_fragshift %d\n", fs->fs_fragshift);
   1349 #else
   1350 		fprintf(stderr, "isblock bad fs_fragshift %d\n",
   1351 		    fs->fs_fragshift);
   1352 #endif
   1353 		return (0);
   1354 	}
   1355 }
   1356 
   1357 /*
   1358  * take a block out of the map
   1359  */
   1360 void
   1361 clrblock(struct fs *fs, unsigned char *cp, int h)
   1362 {
   1363 	switch ((fs)->fs_fragshift) {
   1364 	case 3:
   1365 		cp[h] = 0;
   1366 		return;
   1367 	case 2:
   1368 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
   1369 		return;
   1370 	case 1:
   1371 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
   1372 		return;
   1373 	case 0:
   1374 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
   1375 		return;
   1376 	default:
   1377 #ifdef STANDALONE
   1378 		printf("clrblock bad fs_fragshift %d\n", fs->fs_fragshift);
   1379 #else
   1380 		fprintf(stderr, "clrblock bad fs_fragshift %d\n",
   1381 		    fs->fs_fragshift);
   1382 #endif
   1383 		return;
   1384 	}
   1385 }
   1386 
   1387 /*
   1388  * put a block into the map
   1389  */
   1390 void
   1391 setblock(struct fs *fs, unsigned char *cp, int h)
   1392 {
   1393 	switch (fs->fs_fragshift) {
   1394 	case 3:
   1395 		cp[h] = 0xff;
   1396 		return;
   1397 	case 2:
   1398 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
   1399 		return;
   1400 	case 1:
   1401 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
   1402 		return;
   1403 	case 0:
   1404 		cp[h >> 3] |= (0x01 << (h & 0x7));
   1405 		return;
   1406 	default:
   1407 #ifdef STANDALONE
   1408 		printf("setblock bad fs_frag %d\n", fs->fs_fragshift);
   1409 #else
   1410 		fprintf(stderr, "setblock bad fs_fragshift %d\n",
   1411 		    fs->fs_fragshift);
   1412 #endif
   1413 		return;
   1414 	}
   1415 }
   1416 
   1417 /* copy a direntry to a buffer, in fs byte order */
   1418 static void
   1419 copy_dir(struct direct *dir, struct direct *dbuf)
   1420 {
   1421 	memcpy(dbuf, dir, DIRSIZ(Oflag == 0, dir, 0));
   1422 	if (needswap) {
   1423 		dbuf->d_ino = bswap32(dir->d_ino);
   1424 		dbuf->d_reclen = bswap16(dir->d_reclen);
   1425 		if (Oflag == 0)
   1426 			((struct odirect*)dbuf)->d_namlen =
   1427 				bswap16(((struct odirect*)dir)->d_namlen);
   1428 	}
   1429 }
   1430 
   1431 static int
   1432 ilog2(int val)
   1433 {
   1434 	u_int n;
   1435 
   1436 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
   1437 		if (1 << n == val)
   1438 			return (n);
   1439 	errx(1, "ilog2: %d is not a power of 2\n", val);
   1440 }
   1441 
   1442 static void
   1443 zap_old_sblock(int sblkoff)
   1444 {
   1445 	static int cg0_data;
   1446 	uint32_t oldfs[SBLOCKSIZE / 4];
   1447 	static const struct fsm {
   1448 		uint32_t	offset;
   1449 		uint32_t	magic;
   1450 		uint32_t	mask;
   1451 	} fs_magics[] = {
   1452 		{offsetof(struct fs, fs_magic)/4, FS_UFS1_MAGIC, ~0u},
   1453 		{offsetof(struct fs, fs_magic)/4, FS_UFS2_MAGIC, ~0u},
   1454 		{0, 0x70162, ~0u},		/* LFS_MAGIC */
   1455 		{14, 0xef53, 0xffff},		/* EXT2FS (little) */
   1456 		{14, 0xef530000, 0xffff0000},	/* EXT2FS (big) */
   1457 		{.offset = ~0u},
   1458 	};
   1459 	const struct fsm *fsm;
   1460 
   1461 	if (Nflag)
   1462 		return;
   1463 
   1464 	if (sblkoff == 0)	/* Why did UFS2 add support for this?  sigh. */
   1465 		return;
   1466 
   1467 	if (cg0_data == 0)
   1468 		/* For FFSv1 this could include all the inodes. */
   1469 		cg0_data = cgsblock(&sblock, 0) * sblock.fs_fsize + iobufsize;
   1470 
   1471 	/* Ignore anything that is beyond our filesystem */
   1472 	if ((sblkoff + SBLOCKSIZE)/sectorsize >= fssize)
   1473 		return;
   1474 	/* Zero anything inside our filesystem... */
   1475 	if (sblkoff >= sblock.fs_sblockloc) {
   1476 		/* ...unless we will write that area anyway */
   1477 		if (sblkoff >= cg0_data)
   1478 			wtfs(sblkoff / sectorsize,
   1479 			    roundup(sizeof sblock, sectorsize), iobuf);
   1480 		return;
   1481 	}
   1482 
   1483 	/* The sector might contain boot code, so we must validate it */
   1484 	rdfs(sblkoff/sectorsize, sizeof oldfs, &oldfs);
   1485 	for (fsm = fs_magics; ; fsm++) {
   1486 		uint32_t v;
   1487 		if (fsm->mask == 0)
   1488 			return;
   1489 		v = oldfs[fsm->offset];
   1490 		if ((v & fsm->mask) == fsm->magic ||
   1491 		    (bswap32(v) & fsm->mask) == fsm->magic)
   1492 			break;
   1493 	}
   1494 
   1495 	/* Just zap the magic number */
   1496 	oldfs[fsm->offset] = 0;
   1497 	wtfs(sblkoff/sectorsize, sizeof oldfs, &oldfs);
   1498 }
   1499 
   1500 
   1501 #ifdef MFS
   1502 /*
   1503  * XXX!
   1504  * Attempt to guess how much more space is available for process data.  The
   1505  * heuristic we use is
   1506  *
   1507  *	max_data_limit - (sbrk(0) - etext) - 128kB
   1508  *
   1509  * etext approximates that start address of the data segment, and the 128kB
   1510  * allows some slop for both segment gap between text and data, and for other
   1511  * (libc) malloc usage.
   1512  */
   1513 static void
   1514 calc_memfree(void)
   1515 {
   1516 	extern char etext;
   1517 	struct rlimit rlp;
   1518 	u_long base;
   1519 
   1520 	base = (u_long)sbrk(0) - (u_long)&etext;
   1521 	if (getrlimit(RLIMIT_DATA, &rlp) < 0)
   1522 		perror("getrlimit");
   1523 	rlp.rlim_cur = rlp.rlim_max;
   1524 	if (setrlimit(RLIMIT_DATA, &rlp) < 0)
   1525 		perror("setrlimit");
   1526 	memleft = rlp.rlim_max - base - (128 * 1024);
   1527 }
   1528 
   1529 /*
   1530  * Internal version of malloc that trims the requested size if not enough
   1531  * memory is available.
   1532  */
   1533 static void *
   1534 mkfs_malloc(size_t size)
   1535 {
   1536 	u_long pgsz;
   1537 	caddr_t *memory;
   1538 
   1539 	if (size == 0)
   1540 		return (NULL);
   1541 	if (memleft == 0)
   1542 		calc_memfree();
   1543 
   1544 	pgsz = getpagesize() - 1;
   1545 	size = (size + pgsz) &~ pgsz;
   1546 	if (size > memleft)
   1547 		size = memleft;
   1548 	memleft -= size;
   1549 	memory = mmap(0, size, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE,
   1550 	    -1, 0);
   1551 	return memory != MAP_FAILED ? memory : NULL;
   1552 }
   1553 #endif	/* MFS */
   1554