xref: /netbsd-src/sbin/newfs_ext2fs/mke2fs.c (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /*	$NetBSD: mke2fs.c,v 1.12 2009/03/02 10:57:03 tsutsui Exp $	*/
2 
3 /*-
4  * Copyright (c) 2007 Izumi Tsutsui.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  * Copyright (c) 1980, 1989, 1993
29  *	The Regents of the University of California.  All rights reserved.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions
33  * are met:
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. Redistributions in binary form must reproduce the above copyright
37  *    notice, this list of conditions and the following disclaimer in the
38  *    documentation and/or other materials provided with the distribution.
39  * 3. Neither the name of the University nor the names of its contributors
40  *    may be used to endorse or promote products derived from this software
41  *    without specific prior written permission.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  */
55 
56 /*
57  * Copyright (c) 1997 Manuel Bouyer.
58  *
59  * Redistribution and use in source and binary forms, with or without
60  * modification, are permitted provided that the following conditions
61  * are met:
62  * 1. Redistributions of source code must retain the above copyright
63  *	notice, this list of conditions and the following disclaimer.
64  * 2. Redistributions in binary form must reproduce the above copyright
65  *	notice, this list of conditions and the following disclaimer in the
66  *	documentation and/or other materials provided with the distribution.
67  * 3. All advertising materials mentioning features or use of this software
68  *	must display the following acknowledgement:
69  *	This product includes software developed by Manuel Bouyer.
70  * 4. The name of the author may not be used to endorse or promote products
71  *    derived from this software without specific prior written permission.
72  *
73  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
74  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
75  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
76  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
77  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
78  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
79  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
80  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
81  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
82  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
83  */
84 
85 /*
86  * mke2fs.c: "re-invent (dumb but non-GPLed) wheel as a fun project"
87  *
88  *	In spite of this name, there is no piece of code
89  *	derived from GPLed e2fsprogs written for Linux.
90  *	I referred them only to see how each structure
91  *	member should be initialized.
92  *
93  * Reference:
94  *	- All NetBSD sources under src/sys/ufs/ext2fs and src/sbin/fsck_ext2fs
95  *	- Ext2fs Home Page
96  *		http://e2fsprogs.sourceforge.net/ext2.html
97  *	- Design and Implementation of the Second Extended Filesystem
98  *		http://e2fsprogs.sourceforge.net/ext2intro.html
99  *	- Linux Documentation "The Second Extended Filesystem"
100  *		src/linux/Documentation/filesystems/ext2.txt
101  *		    in the Linux kernel distribution
102  */
103 
104 #include <sys/cdefs.h>
105 #ifndef lint
106 #if 0
107 static char sccsid[] = "@(#)mkfs.c	8.11 (Berkeley) 5/3/95";
108 #else
109 __RCSID("$NetBSD: mke2fs.c,v 1.12 2009/03/02 10:57:03 tsutsui Exp $");
110 #endif
111 #endif /* not lint */
112 
113 #include <sys/param.h>
114 #include <sys/mman.h>
115 #include <sys/time.h>
116 #include <ufs/ext2fs/ext2fs_dinode.h>
117 #include <ufs/ext2fs/ext2fs_dir.h>
118 #include <ufs/ext2fs/ext2fs.h>
119 #include <sys/ioctl.h>
120 
121 #include <err.h>
122 #include <errno.h>
123 #include <string.h>
124 #include <unistd.h>
125 #include <stdlib.h>
126 #include <stddef.h>
127 #include <stdio.h>
128 #include <uuid.h>
129 
130 #include "extern.h"
131 
132 static void initcg(uint);
133 static void zap_old_sblock(daddr_t);
134 static uint cgoverhead(uint);
135 static int fsinit(const struct timeval *);
136 static int makedir(struct ext2fs_direct *, int);
137 static void copy_dir(struct ext2fs_direct *, struct ext2fs_direct *);
138 static void init_resizeino(const struct timeval *);
139 static uint32_t alloc(uint32_t, uint16_t);
140 static void iput(struct ext2fs_dinode *, ino_t);
141 static void rdfs(daddr_t, int, void *);
142 static void wtfs(daddr_t, int, void *);
143 static int ilog2(uint);
144 static int skpc(int, size_t, uint8_t *);
145 
146 /* XXX: some of these macro should be into <ufs/ext2fs/ext2fs.h>? */
147 #define EXT2_DEF_MAX_MNT_COUNT	20
148 #define EXT2_DEF_FSCKINTV	(180 * 24 * 60 * 60)	/* 180 days */
149 #define EXT2_RESERVED_INODES	(EXT2_FIRSTINO - 1)
150 #define EXT2_UMASK		0755
151 
152 #define EXT2_INO_INDEX(ino)	((ino) - 1)		/* no inode zero */
153 
154 #define EXT2_LOSTFOUNDSIZE	16384
155 #define EXT2_LOSTFOUNDINO	EXT2_FIRSTINO		/* XXX: not quite */
156 #define EXT2_LOSTFOUNDUMASK	0700
157 
158 #define EXT2_RESIZEINOUMASK	0600
159 
160 #define NBLOCK_SUPERBLOCK	1
161 #define NBLOCK_BLOCK_BITMAP	1
162 #define NBLOCK_INODE_BITMAP	1
163 
164 #define cgbase(fs, c)	\
165 	((fs)->e2fs.e2fs_first_dblock + (fs)->e2fs.e2fs_bpg * (c))
166 
167 
168 /*
169  * ext2fs super block and group descriptor structures
170  *
171  *   We don't have to use or setup whole in-memory m_ext2fs structure,
172  *   but prepare it to use several macro defined in kernel headers.
173  */
174 union {
175 	struct m_ext2fs m_ext2fs;
176 	char pad[SBSIZE];
177 } ext2fsun;
178 #define sblock	ext2fsun.m_ext2fs
179 #define gd	ext2fsun.m_ext2fs.e2fs_gd
180 
181 static uint8_t *iobuf;		/* for superblock and group descriptors */
182 static int iobufsize;
183 
184 static uint8_t buf[MAXBSIZE];	/* for initcg() and makedir() ops */
185 
186 static int fsi, fso;
187 
188 void
189 mke2fs(const char *fsys, int fi, int fo)
190 {
191 	struct timeval tv;
192 	int64_t minfssize;
193 	uint bcount, fbcount, ficount;
194 	uint blocks_gd, blocks_per_cg, inodes_per_cg, iblocks_per_cg;
195 	uint minblocks_per_cg, blocks_lastcg;
196 	uint ncg, cylno, sboff;
197 	uuid_t uuid;
198 	uint32_t uustat;
199 	int i, len, col, delta, fld_width, max_cols;
200 	struct winsize winsize;
201 
202 	gettimeofday(&tv, NULL);
203 	fsi = fi;
204 	fso = fo;
205 
206 	/*
207 	 * collect and verify the block and fragment sizes
208 	 */
209 	if (!powerof2(bsize)) {
210 		errx(EXIT_FAILURE,
211 		    "block size must be a power of 2, not %u\n",
212 		    bsize);
213 	}
214 	if (!powerof2(fsize)) {
215 		errx(EXIT_FAILURE,
216 		    "fragment size must be a power of 2, not %u\n",
217 		    fsize);
218 	}
219 	if (fsize < sectorsize) {
220 		errx(EXIT_FAILURE,
221 		    "fragment size %u is too small, minimum is %u\n",
222 		    fsize, sectorsize);
223 	}
224 	if (bsize < MINBSIZE) {
225 		errx(EXIT_FAILURE,
226 		    "block size %u is too small, minimum is %u\n",
227 		    bsize, MINBSIZE);
228 	}
229 	if (bsize > EXT2_MAXBSIZE) {
230 		errx(EXIT_FAILURE,
231 		    "block size %u is too large, maximum is %u\n",
232 		    bsize, MAXBSIZE);
233 	}
234 	if (bsize != fsize) {
235 		/*
236 		 * There is no fragment support on current ext2fs (yet?),
237 		 * but some kernel code refers fsize or fpg as bsize or bpg
238 		 * and Linux seems to set the same values to them.
239 		 */
240 		errx(EXIT_FAILURE,
241 		    "block size (%u) can't be different from "
242 		    "fragment size (%u)\n",
243 		    bsize, fsize);
244 	}
245 
246 	/* variable inodesize is REV1 feature */
247 	if (Oflag == 0 && inodesize != EXT2_REV0_DINODE_SIZE) {
248 		errx(EXIT_FAILURE, "GOOD_OLD_REV file system format"
249 		    " doesn't support %d byte inode\n", inodesize);
250 	}
251 
252 	sblock.e2fs.e2fs_log_bsize = ilog2(bsize) - LOG_MINBSIZE;
253 	/* Umm, why not e2fs_log_fsize? */
254 	sblock.e2fs.e2fs_fsize = ilog2(fsize) - LOG_MINBSIZE;
255 
256 	sblock.e2fs_bsize = bsize;
257 	sblock.e2fs_bshift = sblock.e2fs.e2fs_log_bsize + LOG_MINBSIZE;
258 	sblock.e2fs_qbmask = sblock.e2fs_bsize - 1;
259 	sblock.e2fs_bmask = ~sblock.e2fs_qbmask;
260 	sblock.e2fs_fsbtodb = ilog2(sblock.e2fs_bsize) - ilog2(sectorsize);
261 	sblock.e2fs_ipb = sblock.e2fs_bsize / inodesize;
262 
263 	/*
264 	 * Ext2fs preserves BBSIZE (1024 bytes) space at the top for
265 	 * bootloader (though it is not enough at all for our bootloader).
266 	 * If bsize == BBSIZE we have to preserve one block.
267 	 * If bsize > BBSIZE, the first block already contains BBSIZE space
268 	 * before superblock because superblock is allocated at SBOFF and
269 	 * bsize is a power of two (i.e. 2048 bytes or more).
270 	 */
271 	sblock.e2fs.e2fs_first_dblock = (sblock.e2fs_bsize > BBSIZE) ? 0 : 1;
272 	minfssize = fsbtodb(&sblock,
273 	    sblock.e2fs.e2fs_first_dblock +
274 	    NBLOCK_SUPERBLOCK +
275 	    1 /* at least one group descriptor */ +
276 	    NBLOCK_BLOCK_BITMAP	+
277 	    NBLOCK_INODE_BITMAP +
278 	    1 /* at least one inode table block */ +
279 	    1 /* at least one data block for rootdir */ +
280 	    1 /* at least one data block for data */
281 	    );			/* XXX and more? */
282 
283 	if (fssize < minfssize)
284 		errx(EXIT_FAILURE, "Filesystem size %" PRId64
285 		    " < minimum size of %" PRId64 "\n", fssize, minfssize);
286 
287 	bcount = dbtofsb(&sblock, fssize);
288 
289 	/*
290 	 * While many people claim that ext2fs is a (bad) clone of ufs/ffs,
291 	 * it isn't actual ffs so maybe we should call it "block group"
292 	 * as their native name rather than ffs derived "cylinder group."
293 	 * But we'll use the latter here since other kernel sources use it.
294 	 * (I also agree "cylinder" based allocation is obsolete though)
295 	 */
296 
297 	/* maybe "simple is the best" */
298 	blocks_per_cg = sblock.e2fs_bsize * NBBY;
299 
300 	ncg = howmany(bcount - sblock.e2fs.e2fs_first_dblock, blocks_per_cg);
301 	blocks_gd = howmany(sizeof(struct ext2_gd) * ncg, bsize);
302 
303 	/* check range of inode number */
304 	if (num_inodes < EXT2_FIRSTINO)
305 		num_inodes = EXT2_FIRSTINO;	/* needs reserved inodes + 1 */
306 	if (num_inodes > UINT16_MAX * ncg)
307 		num_inodes = UINT16_MAX * ncg;	/* ext2bgd_nifree is uint16_t */
308 
309 	inodes_per_cg = num_inodes / ncg;
310 	iblocks_per_cg = howmany(inodesize * inodes_per_cg, bsize);
311 
312 	/* Check that the last cylinder group has enough space for inodes */
313 	minblocks_per_cg =
314 	    NBLOCK_BLOCK_BITMAP +
315 	    NBLOCK_INODE_BITMAP +
316 	    iblocks_per_cg +
317 	    1;	/* at least one data block */
318 	if (Oflag == 0 || cg_has_sb(ncg - 1) != 0)
319 		minblocks_per_cg += NBLOCK_SUPERBLOCK + blocks_gd;
320 
321 	blocks_lastcg = bcount - sblock.e2fs.e2fs_first_dblock -
322 	    blocks_per_cg * (ncg - 1);
323 	if (blocks_lastcg < minblocks_per_cg) {
324 		/*
325 		 * Since we make all the cylinder groups the same size, the
326 		 * last will only be small if there are more than one
327 		 * cylinder groups. If the last one is too small to store
328 		 * filesystem data, just kill it.
329 		 *
330 		 * XXX: Does fsck_ext2fs(8) properly handle this case?
331 		 */
332 		bcount -= blocks_lastcg;
333 		ncg--;
334 		blocks_lastcg = blocks_per_cg;
335 		blocks_gd = howmany(sizeof(struct ext2_gd) * ncg, bsize);
336 		inodes_per_cg = num_inodes / ncg;
337 	}
338 	/* roundup inodes_per_cg to make it use whole inode table blocks */
339 	inodes_per_cg = roundup(inodes_per_cg, sblock.e2fs_ipb);
340 	num_inodes = inodes_per_cg * ncg;
341 	iblocks_per_cg = inodes_per_cg / sblock.e2fs_ipb;
342 
343 	/* XXX: probably we should check these adjusted values again */
344 
345 	sblock.e2fs.e2fs_bcount = bcount;
346 	sblock.e2fs.e2fs_icount = num_inodes;
347 
348 	sblock.e2fs_ncg = ncg;
349 	sblock.e2fs_ngdb = blocks_gd;
350 	sblock.e2fs_itpg = iblocks_per_cg;
351 
352 	sblock.e2fs.e2fs_rbcount = sblock.e2fs.e2fs_bcount * minfree / 100;
353 	/* e2fs_fbcount will be accounted later */
354 	/* e2fs_ficount will be accounted later */
355 
356 	sblock.e2fs.e2fs_bpg = blocks_per_cg;
357 	sblock.e2fs.e2fs_fpg = blocks_per_cg;
358 
359 	sblock.e2fs.e2fs_ipg = inodes_per_cg;
360 
361 	sblock.e2fs.e2fs_mtime = 0;
362 	sblock.e2fs.e2fs_wtime = tv.tv_sec;
363 	sblock.e2fs.e2fs_mnt_count = 0;
364 	/* XXX: should add some entropy to avoid checking all fs at once? */
365 	sblock.e2fs.e2fs_max_mnt_count = EXT2_DEF_MAX_MNT_COUNT;
366 
367 	sblock.e2fs.e2fs_magic = E2FS_MAGIC;
368 	sblock.e2fs.e2fs_state = E2FS_ISCLEAN;
369 	sblock.e2fs.e2fs_beh = E2FS_BEH_DEFAULT;
370 	sblock.e2fs.e2fs_minrev = 0;
371 	sblock.e2fs.e2fs_lastfsck = tv.tv_sec;
372 	sblock.e2fs.e2fs_fsckintv = EXT2_DEF_FSCKINTV;
373 
374 	/*
375 	 * Maybe we can use E2FS_OS_FREEBSD here and it would be more proper,
376 	 * but the purpose of this newfs_ext2fs(8) command is to provide
377 	 * a filesystem which can be recognized by firmware on some
378 	 * Linux based appliances that can load bootstrap files only from
379 	 * (their native) ext2fs, and anyway we will (and should) try to
380 	 * act like them as much as possible.
381 	 *
382 	 * Anyway, I hope that all newer such boxes will keep their support
383 	 * for the "GOOD_OLD_REV" ext2fs.
384 	 */
385 	sblock.e2fs.e2fs_creator = E2FS_OS_LINUX;
386 
387 	if (Oflag == 0) {
388 		sblock.e2fs.e2fs_rev = E2FS_REV0;
389 		sblock.e2fs.e2fs_features_compat   = 0;
390 		sblock.e2fs.e2fs_features_incompat = 0;
391 		sblock.e2fs.e2fs_features_rocompat = 0;
392 	} else {
393 		sblock.e2fs.e2fs_rev = E2FS_REV1;
394 		/*
395 		 * e2fsprogs say "REV1" is "dynamic" so
396 		 * it isn't quite a version and maybe it means
397 		 * "extended from REV0 so check compat features."
398 		 *
399 		 * XXX: We don't have any native tool to activate
400 		 *      the EXT2F_COMPAT_RESIZE feature and
401 		 *      fsck_ext2fs(8) might not fix structures for it.
402 		 */
403 		sblock.e2fs.e2fs_features_compat   = EXT2F_COMPAT_RESIZE;
404 		sblock.e2fs.e2fs_features_incompat = EXT2F_INCOMPAT_FTYPE;
405 		sblock.e2fs.e2fs_features_rocompat =
406 		    EXT2F_ROCOMPAT_SPARSESUPER | EXT2F_ROCOMPAT_LARGEFILE;
407 	}
408 
409 	sblock.e2fs.e2fs_ruid = geteuid();
410 	sblock.e2fs.e2fs_rgid = getegid();
411 
412 	sblock.e2fs.e2fs_first_ino = EXT2_FIRSTINO;
413 	sblock.e2fs.e2fs_inode_size = inodesize;
414 
415 	/* e2fs_block_group_nr is set on writing superblock to each group */
416 
417 	uuid_create(&uuid, &uustat);
418 	if (uustat != uuid_s_ok)
419 		errx(EXIT_FAILURE, "Failed to generate uuid\n");
420 	uuid_enc_le(sblock.e2fs.e2fs_uuid, &uuid);
421 	if (volname != NULL) {
422 		if (strlen(volname) > sizeof(sblock.e2fs.e2fs_vname))
423 			errx(EXIT_FAILURE, "Volume name is too long");
424 		strlcpy(sblock.e2fs.e2fs_vname, volname,
425 		    sizeof(sblock.e2fs.e2fs_vname));
426 	}
427 
428 	sblock.e2fs.e2fs_fsmnt[0] = '\0';
429 	sblock.e2fs_fsmnt[0] = '\0';
430 
431 	sblock.e2fs.e2fs_algo = 0;		/* XXX unsupported? */
432 	sblock.e2fs.e2fs_prealloc = 0;		/* XXX unsupported? */
433 	sblock.e2fs.e2fs_dir_prealloc = 0;	/* XXX unsupported? */
434 
435 	/* calculate blocks for reserved group descriptors for resize */
436 	sblock.e2fs.e2fs_reserved_ngdb = 0;
437 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
438 	    (sblock.e2fs.e2fs_features_compat & EXT2F_COMPAT_RESIZE) != 0) {
439 		uint64_t target_blocks;
440 		uint target_ncg, target_ngdb, reserved_ngdb;
441 
442 		/* reserve descriptors for size as 1024 times as current */
443 		target_blocks =
444 		    (sblock.e2fs.e2fs_bcount - sblock.e2fs.e2fs_first_dblock)
445 		    * 1024ULL;
446 		/* number of blocks must be in uint32_t */
447 		if (target_blocks > UINT32_MAX)
448 			target_blocks = UINT32_MAX;
449 		target_ncg = howmany(target_blocks, sblock.e2fs.e2fs_bpg);
450 		target_ngdb = howmany(sizeof(struct ext2_gd) * target_ncg,
451 		    sblock.e2fs_bsize);
452 		/*
453 		 * Reserved group descriptor blocks are preserved as
454 		 * the second level double indirect reference blocks in
455 		 * the EXT2_RESIZEINO inode, so the maximum number of
456 		 * the blocks is NINDIR(fs).
457 		 * (see also descriptions in init_resizeino() function)
458 		 *
459 		 * We check a number including current e2fs_ngdb here
460 		 * because they will be moved into reserved gdb on
461 		 * possible future size shrink, though e2fsprogs don't
462 		 * seem to care about it.
463 		 */
464 		if (target_ngdb > NINDIR(&sblock))
465 			target_ngdb = NINDIR(&sblock);
466 
467 		reserved_ngdb = target_ngdb - sblock.e2fs_ngdb;
468 
469 		/* make sure reserved_ngdb fits in the last cg */
470 		if (reserved_ngdb >= blocks_lastcg - cgoverhead(ncg - 1))
471 			reserved_ngdb = blocks_lastcg - cgoverhead(ncg - 1);
472 		if (reserved_ngdb == 0) {
473 			/* if no space for reserved gdb, disable the feature */
474 			sblock.e2fs.e2fs_features_compat &=
475 			    ~EXT2F_COMPAT_RESIZE;
476 		}
477 		sblock.e2fs.e2fs_reserved_ngdb = reserved_ngdb;
478 	}
479 
480 	/*
481 	 * Initialize group descriptors
482 	 */
483 	gd = malloc(sblock.e2fs_ngdb * bsize);
484 	if (gd == NULL)
485 		errx(EXIT_FAILURE, "Can't allocate descriptors buffer");
486 	memset(gd, 0, sblock.e2fs_ngdb * bsize);
487 
488 	fbcount = 0;
489 	ficount = 0;
490 	for (cylno = 0; cylno < ncg; cylno++) {
491 		uint boffset;
492 
493 		boffset = cgbase(&sblock, cylno);
494 		if (sblock.e2fs.e2fs_rev == E2FS_REV0 ||
495 		    (sblock.e2fs.e2fs_features_rocompat &
496 		     EXT2F_ROCOMPAT_SPARSESUPER) == 0 ||
497 		    cg_has_sb(cylno)) {
498 			boffset += NBLOCK_SUPERBLOCK + sblock.e2fs_ngdb;
499 			if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
500 			    (sblock.e2fs.e2fs_features_compat &
501 			     EXT2F_COMPAT_RESIZE) != 0)
502 				boffset += sblock.e2fs.e2fs_reserved_ngdb;
503 		}
504 		gd[cylno].ext2bgd_b_bitmap = boffset;
505 		boffset += NBLOCK_BLOCK_BITMAP;
506 		gd[cylno].ext2bgd_i_bitmap = boffset;
507 		boffset += NBLOCK_INODE_BITMAP;
508 		gd[cylno].ext2bgd_i_tables = boffset;
509 		if (cylno == (ncg - 1))
510 			gd[cylno].ext2bgd_nbfree =
511 			    blocks_lastcg - cgoverhead(cylno);
512 		else
513 			gd[cylno].ext2bgd_nbfree =
514 			    sblock.e2fs.e2fs_bpg - cgoverhead(cylno);
515 		fbcount += gd[cylno].ext2bgd_nbfree;
516 		gd[cylno].ext2bgd_nifree = sblock.e2fs.e2fs_ipg;
517 		if (cylno == 0) {
518 			/* take reserved inodes off nifree */
519 			gd[cylno].ext2bgd_nifree -= EXT2_RESERVED_INODES;
520 		}
521 		ficount += gd[cylno].ext2bgd_nifree;
522 		gd[cylno].ext2bgd_ndirs = 0;
523 	}
524 	sblock.e2fs.e2fs_fbcount = fbcount;
525 	sblock.e2fs.e2fs_ficount = ficount;
526 
527 	/*
528 	 * Dump out summary information about file system.
529 	 */
530 	if (verbosity > 0) {
531 		printf("%s: %u.%1uMB (%" PRId64 " sectors) "
532 		    "block size %u, fragment size %u\n",
533 		    fsys,
534 		    (uint)(((uint64_t)bcount * bsize) / (1024 * 1024)),
535 		    (uint)((uint64_t)bcount * bsize -
536 		    rounddown((uint64_t)bcount * bsize, 1024 * 1024))
537 		    / 1024 / 100,
538 		    fssize, bsize, fsize);
539 		printf("\tusing %u block groups of %u.0MB, %u blks, "
540 		    "%u inodes.\n",
541 		    ncg, bsize * sblock.e2fs.e2fs_bpg / (1024 * 1024),
542 		    sblock.e2fs.e2fs_bpg, sblock.e2fs.e2fs_ipg);
543 	}
544 
545 	/*
546 	 * allocate space for superblock and group descriptors
547 	 */
548 	iobufsize = (NBLOCK_SUPERBLOCK + sblock.e2fs_ngdb) * sblock.e2fs_bsize;
549 	iobuf = mmap(0, iobufsize, PROT_READ|PROT_WRITE,
550 	    MAP_ANON|MAP_PRIVATE, -1, 0);
551 	if (iobuf == NULL)
552 		errx(EXIT_FAILURE, "Cannot allocate I/O buffer\n");
553 	memset(iobuf, 0, iobufsize);
554 
555 	/*
556 	 * We now start writing to the filesystem
557 	 */
558 
559 	if (!Nflag) {
560 		static const uint pbsize[] = { 1024, 2048, 4096, 0 };
561 		uint pblock, epblock;
562 		/*
563 		 * Validate the given file system size.
564 		 * Verify that its last block can actually be accessed.
565 		 * Convert to file system fragment sized units.
566 		 */
567 		if (fssize <= 0)
568 			errx(EXIT_FAILURE, "Preposterous size %" PRId64 "\n",
569 			    fssize);
570 		wtfs(fssize - 1, sectorsize, iobuf);
571 
572 		/*
573 		 * Ensure there is nothing that looks like a filesystem
574 		 * superblock anywhere other than where ours will be.
575 		 * If fsck_ext2fs finds the wrong one all hell breaks loose!
576 		 *
577 		 * XXX: needs to check how fsck_ext2fs programs even
578 		 *      on other OSes determine alternate superblocks
579 		 */
580 		for (i = 0; pbsize[i] != 0; i++) {
581 			epblock = (uint64_t)bcount * bsize / pbsize[i];
582 			for (pblock = ((pbsize[i] == SBSIZE) ? 1 : 0);
583 			    pblock < epblock;
584 			    pblock += pbsize[i] * NBBY /* bpg */)
585 				zap_old_sblock((daddr_t)pblock *
586 				    pbsize[i] / sectorsize);
587 		}
588 	}
589 
590 	if (verbosity >= 3)
591 		printf("super-block backups (for fsck_ext2fs -b #) at:\n");
592 	/* If we are printing more than one line of numbers, line up columns */
593 	fld_width = verbosity < 4 ? 1 : snprintf(NULL, 0, "%" PRIu64,
594 	    (uint64_t)cgbase(&sblock, ncg - 1));
595 	/* Get terminal width */
596 	if (ioctl(fileno(stdout), TIOCGWINSZ, &winsize) == 0)
597 		max_cols = winsize.ws_col;
598 	else
599 		max_cols = 80;
600 	if (Nflag && verbosity == 3)
601 		/* Leave space to add " ..." after one row of numbers */
602 		max_cols -= 4;
603 #define BASE 0x10000	/* For some fixed-point maths */
604 	col = 0;
605 	delta = verbosity > 2 ? 0 : max_cols * BASE / ncg;
606 	for (cylno = 0; cylno < ncg; cylno++) {
607 		fflush(stdout);
608 		initcg(cylno);
609 		if (verbosity < 2)
610 			continue;
611 		/* the first one is a master, not backup */
612 		if (cylno == 0)
613 			continue;
614 		/* skip if this cylinder doesn't have a backup */
615 		if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
616 		    (sblock.e2fs.e2fs_features_rocompat &
617 		     EXT2F_ROCOMPAT_SPARSESUPER) != 0 &&
618 		    cg_has_sb(cylno) == 0)
619 			continue;
620 
621 		if (delta > 0) {
622 			if (Nflag)
623 				/* No point doing dots for -N */
624 				break;
625 			/* Print dots scaled to end near RH margin */
626 			for (col += delta; col > BASE; col -= BASE)
627 				printf(".");
628 			continue;
629 		}
630 		/* Print superblock numbers */
631 		len = printf(" %*" PRIu64 "," + !col, fld_width,
632 		    (uint64_t)cgbase(&sblock, cylno));
633 		col += len;
634 		if (col + len < max_cols)
635 			/* Next number fits */
636 			continue;
637 		/* Next number won't fit, need a newline */
638 		if (verbosity <= 3) {
639 			/* Print dots for subsequent cylinder groups */
640 			delta = sblock.e2fs_ncg - cylno - 1;
641 			if (delta != 0) {
642 				if (Nflag) {
643 					printf(" ...");
644 					break;
645 				}
646 				delta = max_cols * BASE / delta;
647 			}
648 		}
649 		col = 0;
650 		printf("\n");
651 	}
652 #undef BASE
653 	if (col > 0)
654 		printf("\n");
655 	if (Nflag)
656 		return;
657 
658 	/*
659 	 * Now construct the initial file system,
660 	 */
661 	if (fsinit(&tv) == 0)
662 		errx(EXIT_FAILURE, "Error making filesystem");
663 	/*
664 	 * Write out the superblock and group descriptors
665 	 */
666 	sblock.e2fs.e2fs_block_group_nr = 0;
667 	sboff = 0;
668 	if (cgbase(&sblock, 0) == 0) {
669 		/*
670 		 * If the first block contains the boot block sectors,
671 		 * (i.e. in case of sblock.e2fs.e2fs_bsize > BBSIZE)
672 		 * we have to preserve data in it.
673 		 */
674 		sboff = SBOFF;
675 	}
676 	e2fs_sbsave(&sblock.e2fs, (struct ext2fs *)(iobuf + sboff));
677 	e2fs_cgsave(gd, (struct ext2_gd *)(iobuf + sblock.e2fs_bsize),
678 	   sizeof(struct ext2_gd) * sblock.e2fs_ncg);
679 	wtfs(fsbtodb(&sblock, cgbase(&sblock, 0)) + sboff / sectorsize,
680 	    iobufsize - sboff, iobuf + sboff);
681 
682 	munmap(iobuf, iobufsize);
683 }
684 
685 /*
686  * Initialize a cylinder (block) group.
687  */
688 void
689 initcg(uint cylno)
690 {
691 	uint nblcg, i, j, sboff;
692 	struct ext2fs_dinode *dp;
693 
694 	/*
695 	 * Make a copy of the superblock and group descriptors.
696 	 */
697 	if (sblock.e2fs.e2fs_rev == E2FS_REV0 ||
698 	    (sblock.e2fs.e2fs_features_rocompat &
699 	     EXT2F_ROCOMPAT_SPARSESUPER) == 0 ||
700 	    cg_has_sb(cylno)) {
701 		sblock.e2fs.e2fs_block_group_nr = cylno;
702 		sboff = 0;
703 		if (cgbase(&sblock, cylno) == 0) {
704 			/* preserve data in bootblock in cg0 */
705 			sboff = SBOFF;
706 		}
707 		e2fs_sbsave(&sblock.e2fs, (struct ext2fs *)(iobuf + sboff));
708 		e2fs_cgsave(gd, (struct ext2_gd *)(iobuf +
709 		    sblock.e2fs_bsize * NBLOCK_SUPERBLOCK),
710 		    sizeof(struct ext2_gd) * sblock.e2fs_ncg);
711 		/* write superblock and group descriptor backups */
712 		wtfs(fsbtodb(&sblock, cgbase(&sblock, cylno)) +
713 		    sboff / sectorsize, iobufsize - sboff, iobuf + sboff);
714 	}
715 
716 	/*
717 	 * Initialize block bitmap.
718 	 */
719 	memset(buf, 0, sblock.e2fs_bsize);
720 	if (cylno == (sblock.e2fs_ncg - 1)) {
721 		/* The last group could have less blocks than e2fs_bpg. */
722 		nblcg = sblock.e2fs.e2fs_bcount -
723 		    cgbase(&sblock, sblock.e2fs_ncg - 1);
724 		for (i = nblcg; i < roundup(nblcg, NBBY); i++)
725 			setbit(buf, i);
726 		memset(&buf[i / NBBY], ~0U, sblock.e2fs.e2fs_bpg - i);
727 	}
728 	/* set overhead (superblock, group descriptor etc.) blocks used */
729 	for (i = 0; i < cgoverhead(cylno) / NBBY; i++)
730 		buf[i] = ~0;
731 	i = i * NBBY;
732 	for (; i < cgoverhead(cylno); i++)
733 		setbit(buf, i);
734 	wtfs(fsbtodb(&sblock, gd[cylno].ext2bgd_b_bitmap), sblock.e2fs_bsize,
735 	    buf);
736 
737 	/*
738 	 * Initialize inode bitmap.
739 	 *
740 	 *  Assume e2fs_ipg is a multiple of NBBY since
741 	 *  it's a multiple of e2fs_ipb (as we did above).
742 	 *  Note even (possibly smaller) the last group has the same e2fs_ipg.
743 	 */
744 	i = sblock.e2fs.e2fs_ipg / NBBY;
745 	memset(buf, 0, i);
746 	memset(buf + i, ~0U, sblock.e2fs_bsize - i);
747 	if (cylno == 0) {
748 		/* mark reserved inodes */
749 		for (i = 1; i < EXT2_FIRSTINO; i++)
750 			setbit(buf, EXT2_INO_INDEX(i));
751 	}
752 	wtfs(fsbtodb(&sblock, gd[cylno].ext2bgd_i_bitmap), sblock.e2fs_bsize,
753 	    buf);
754 
755 	/*
756 	 * Initialize inode tables.
757 	 *
758 	 *  Just initialize generation numbers for NFS security.
759 	 *  XXX: sys/ufs/ext2fs/ext2fs_alloc.c:ext2fs_valloc() seems
760 	 *       to override these generated numbers.
761 	 */
762 	memset(buf, 0, sblock.e2fs_bsize);
763 	for (i = 0; i < sblock.e2fs_itpg; i++) {
764 		for (j = 0; j < sblock.e2fs_ipb; j++) {
765 			dp = (struct ext2fs_dinode *)(buf + inodesize * j);
766 			/* h2fs32() just for consistency */
767 			dp->e2di_gen = h2fs32(arc4random());
768 		}
769 		wtfs(fsbtodb(&sblock, gd[cylno].ext2bgd_i_tables + i),
770 		    sblock.e2fs_bsize, buf);
771 	}
772 }
773 
774 /*
775  * Zap possible lingering old superblock data
776  */
777 static void
778 zap_old_sblock(daddr_t sec)
779 {
780 	static daddr_t cg0_data;
781 	uint32_t oldfs[SBSIZE / sizeof(uint32_t)];
782 	static const struct fsm {
783 		uint32_t offset;
784 		uint32_t magic;
785 		uint32_t mask;
786 	} fs_magics[] = {
787 		{offsetof(struct ext2fs, e2fs_magic) / 4, E2FS_MAGIC, 0xffff},
788 		{offsetof(struct ext2fs, e2fs_magic) / 4,
789 		    E2FS_MAGIC << 16, 0xffff0000},
790 		{14, 0xef530000, 0xffff0000},	/* EXT2FS (big) */
791 		{0x55c / 4, 0x00011954, ~0U},	/* FS_UFS1_MAGIC */
792 		{0x55c / 4, 0x19540119, ~0U},	/* FS_UFS2_MAGIC */
793 		{0, 0x70162, ~0U},		/* LFS_MAGIC */
794 		{.offset = ~0U},
795 	};
796 	const struct fsm *fsm;
797 
798 	if (Nflag)
799 		return;
800 
801 	/* don't override data before superblock */
802 	if (sec < SBOFF / sectorsize)
803 		return;
804 
805 	if (cg0_data == 0) {
806 		cg0_data =
807 		    ((daddr_t)sblock.e2fs.e2fs_first_dblock + cgoverhead(0)) *
808 		    sblock.e2fs_bsize / sectorsize;
809 	}
810 
811 	/* Ignore anything that is beyond our filesystem */
812 	if (sec >= fssize)
813 		return;
814 	/* Zero anything inside our filesystem... */
815 	if (sec >= sblock.e2fs.e2fs_first_dblock * bsize / sectorsize) {
816 		/* ...unless we will write that area anyway */
817 		if (sec >= cg0_data)
818 			/* assume iobuf is zero'ed here */
819 			wtfs(sec, roundup(SBSIZE, sectorsize), iobuf);
820 		return;
821 	}
822 
823 	/*
824 	 * The sector might contain boot code, so we must validate it
825 	 *
826 	 * XXX: ext2fs won't preserve data after SBOFF,
827 	 *      but first_dblock could have a different value.
828 	 */
829 	rdfs(sec, sizeof(oldfs), &oldfs);
830 	for (fsm = fs_magics;; fsm++) {
831 		uint32_t v;
832 		if (fsm->mask == 0)
833 			return;
834 		v = oldfs[fsm->offset];
835 		if ((v & fsm->mask) == fsm->magic ||
836 		    (bswap32(v) & fsm->mask) == fsm->magic)
837 			break;
838 	}
839 
840 	/* Just zap the magic number */
841 	oldfs[fsm->offset] = 0;
842 	wtfs(sec, sizeof(oldfs), &oldfs);
843 }
844 
845 /*
846  * uint cgoverhead(uint c)
847  *
848  * 	Return a number of reserved blocks on the specified group.
849  * 	XXX: should be shared with src/sbin/fsck_ext2fs/setup.c
850  */
851 uint
852 cgoverhead(uint c)
853 {
854 	uint overh;
855 
856 	overh = NBLOCK_BLOCK_BITMAP + NBLOCK_INODE_BITMAP + sblock.e2fs_itpg;
857 
858 	if (sblock.e2fs.e2fs_rev == E2FS_REV0 ||
859 	    (sblock.e2fs.e2fs_features_rocompat &
860 	     EXT2F_ROCOMPAT_SPARSESUPER) == 0 ||
861 	    cg_has_sb(c) != 0) {
862 		overh += NBLOCK_SUPERBLOCK + sblock.e2fs_ngdb;
863 
864 		if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
865 		    (sblock.e2fs.e2fs_features_compat &
866 		     EXT2F_COMPAT_RESIZE) != 0)
867 			overh += sblock.e2fs.e2fs_reserved_ngdb;
868 	}
869 
870 	return overh;
871 }
872 
873 /*
874  * Initialize the file system
875  */
876 
877 #define LOSTDIR		/* e2fsck complains if there is no lost+found */
878 
879 #define	PREDEFDIR	2
880 
881 #ifdef LOSTDIR
882 #define	PREDEFROOTDIR	(PREDEFDIR + 1)
883 #else
884 #define	PREDEFROOTDIR	PREDEFDIR
885 #endif
886 
887 struct ext2fs_direct root_dir[] = {
888 	{ EXT2_ROOTINO, 0, 1, 0, "." },
889 	{ EXT2_ROOTINO, 0, 2, 0, ".." },
890 #ifdef LOSTDIR
891 	{ EXT2_LOSTFOUNDINO, 0, 10, 0, "lost+found" },
892 #endif
893 };
894 
895 #ifdef LOSTDIR
896 struct ext2fs_direct lost_found_dir[] = {
897 	{ EXT2_LOSTFOUNDINO, 0, 1, 0, "." },
898 	{ EXT2_ROOTINO, 0, 2, 0, ".." },
899 };
900 struct ext2fs_direct pad_dir = { 0, sizeof(struct ext2fs_direct), 0, 0, "" };
901 #endif
902 
903 int
904 fsinit(const struct timeval *tv)
905 {
906 	struct ext2fs_dinode node;
907 #ifdef LOSTDIR
908 	uint i, nblks_lostfound, blk;
909 #endif
910 
911 	/*
912 	 * Initialize the inode for the resizefs feature
913 	 */
914 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
915 	    (sblock.e2fs.e2fs_features_compat & EXT2F_COMPAT_RESIZE) != 0)
916 		init_resizeino(tv);
917 
918 	/*
919 	 * Initialize the node
920 	 */
921 
922 #ifdef LOSTDIR
923 	/*
924 	 * Create the lost+found directory
925 	 */
926 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
927 	    sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE) {
928 		lost_found_dir[0].e2d_type = EXT2_FT_DIR;
929 		lost_found_dir[1].e2d_type = EXT2_FT_DIR;
930 	}
931 	(void)makedir(lost_found_dir, __arraycount(lost_found_dir));
932 
933 	/* prepare a bit large directory for preserved files */
934 	nblks_lostfound = EXT2_LOSTFOUNDSIZE / sblock.e2fs_bsize;
935 	/* ...but only with direct blocks */
936 	if (nblks_lostfound > NDADDR)
937 		nblks_lostfound = NDADDR;
938 
939 	memset(&node, 0, sizeof(node));
940 	node.e2di_mode = EXT2_IFDIR | EXT2_LOSTFOUNDUMASK;
941 	node.e2di_uid = geteuid();
942 	node.e2di_size = sblock.e2fs_bsize * nblks_lostfound;
943 	node.e2di_atime = tv->tv_sec;
944 	node.e2di_ctime = tv->tv_sec;
945 	node.e2di_mtime = tv->tv_sec;
946 	node.e2di_gid = getegid();
947 	node.e2di_nlink = PREDEFDIR;
948 	/* e2di_nblock is a number of disk blocks, not ext2fs blocks */
949 	node.e2di_nblock = fsbtodb(&sblock, nblks_lostfound);
950 	node.e2di_blocks[0] = alloc(sblock.e2fs_bsize, node.e2di_mode);
951 	if (node.e2di_blocks[0] == 0) {
952 		printf("%s: can't allocate block for lost+found\n", __func__);
953 		return 0;
954 	}
955 	for (i = 1; i < nblks_lostfound; i++) {
956 		blk = alloc(sblock.e2fs_bsize, 0);
957 		if (blk == 0) {
958 			printf("%s: can't allocate blocks for lost+found\n",
959 			    __func__);
960 			return 0;
961 		}
962 		node.e2di_blocks[i] = blk;
963 	}
964 	wtfs(fsbtodb(&sblock, node.e2di_blocks[0]), sblock.e2fs_bsize, buf);
965 	pad_dir.e2d_reclen = sblock.e2fs_bsize;
966 	for (i = 1; i < nblks_lostfound; i++) {
967 		memset(buf, 0, sblock.e2fs_bsize);
968 		copy_dir(&pad_dir, (struct ext2fs_direct *)buf);
969 		wtfs(fsbtodb(&sblock, node.e2di_blocks[i]), sblock.e2fs_bsize,
970 		    buf);
971 	}
972 	iput(&node, EXT2_LOSTFOUNDINO);
973 #endif
974 	/*
975 	 * create the root directory
976 	 */
977 	memset(&node, 0, sizeof(node));
978 	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
979 	    sblock.e2fs.e2fs_features_incompat & EXT2F_INCOMPAT_FTYPE) {
980 		root_dir[0].e2d_type = EXT2_FT_DIR;
981 		root_dir[1].e2d_type = EXT2_FT_DIR;
982 #ifdef LOSTDIR
983 		root_dir[2].e2d_type = EXT2_FT_DIR;
984 #endif
985 	}
986 	node.e2di_mode = EXT2_IFDIR | EXT2_UMASK;
987 	node.e2di_uid = geteuid();
988 	node.e2di_size = makedir(root_dir, __arraycount(root_dir));
989 	node.e2di_atime = tv->tv_sec;
990 	node.e2di_ctime = tv->tv_sec;
991 	node.e2di_mtime = tv->tv_sec;
992 	node.e2di_gid = getegid();
993 	node.e2di_nlink = PREDEFROOTDIR;
994 	/* e2di_nblock is a number of disk block, not ext2fs block */
995 	node.e2di_nblock = fsbtodb(&sblock, 1);
996 	node.e2di_blocks[0] = alloc(node.e2di_size, node.e2di_mode);
997 	if (node.e2di_blocks[0] == 0) {
998 		printf("%s: can't allocate block for root dir\n", __func__);
999 		return 0;
1000 	}
1001 	wtfs(fsbtodb(&sblock, node.e2di_blocks[0]), sblock.e2fs_bsize, buf);
1002 	iput(&node, EXT2_ROOTINO);
1003 	return 1;
1004 }
1005 
1006 /*
1007  * Construct a set of directory entries in "buf".
1008  * return size of directory.
1009  */
1010 int
1011 makedir(struct ext2fs_direct *protodir, int entries)
1012 {
1013 	uint8_t *cp;
1014 	uint i, spcleft;
1015 	uint dirblksiz;
1016 
1017 	dirblksiz = sblock.e2fs_bsize;
1018 	memset(buf, 0, dirblksiz);
1019 	spcleft = dirblksiz;
1020 	for (cp = buf, i = 0; i < entries - 1; i++) {
1021 		protodir[i].e2d_reclen = EXT2FS_DIRSIZ(protodir[i].e2d_namlen);
1022 		copy_dir(&protodir[i], (struct ext2fs_direct *)cp);
1023 		cp += protodir[i].e2d_reclen;
1024 		spcleft -= protodir[i].e2d_reclen;
1025 	}
1026 	protodir[i].e2d_reclen = spcleft;
1027 	copy_dir(&protodir[i], (struct ext2fs_direct *)cp);
1028 	return dirblksiz;
1029 }
1030 
1031 /*
1032  * Copy a direntry to a buffer, in fs byte order
1033  */
1034 static void
1035 copy_dir(struct ext2fs_direct *dir, struct ext2fs_direct *dbuf)
1036 {
1037 
1038 	memcpy(dbuf, dir, EXT2FS_DIRSIZ(dir->e2d_namlen));
1039 	dbuf->e2d_ino = h2fs32(dir->e2d_ino);
1040 	dbuf->e2d_reclen = h2fs16(dir->e2d_reclen);
1041 }
1042 
1043 /*
1044  * void init_resizeino(const struct timeval *tv);
1045  *
1046  *	Initialize the EXT2_RESEIZE_INO inode to preserve
1047  *	reserved group descriptor blocks for future growth of this ext2fs.
1048  */
1049 void
1050 init_resizeino(const struct timeval *tv)
1051 {
1052 	struct ext2fs_dinode node;
1053 	uint64_t isize;
1054 	uint32_t *dindir_block, *reserved_gdb;
1055 	uint nblock, i, cylno, n;
1056 
1057 	memset(&node, 0, sizeof(node));
1058 
1059 	/*
1060 	 * Note this function only prepares required structures for
1061 	 * future resize. It's a quite different work to implement
1062 	 * a utility like resize_ext2fs(8) which handles actual
1063 	 * resize ops even on offline.
1064 	 *
1065 	 * Anyway, I'm not sure if there is any documentation about
1066 	 * this resize ext2fs feature and related data structures,
1067 	 * and I've written this function based on things what I see
1068 	 * on some existing implementation and real file system data
1069 	 * created by existing tools. To be honest, they are not
1070 	 * so easy to read, so I will try to implement it here without
1071 	 * any dumb optimization for people who would eventually
1072 	 * work on "yet another wheel" like resize_ext2fs(8).
1073 	 */
1074 
1075 	/*
1076 	 * I'm not sure what type is appropriate for this inode.
1077 	 * The release notes of e2fsprogs says they changed e2fsck to allow
1078 	 * IFREG for RESIZEINO since a certain resize tool used it. Hmm.
1079 	 */
1080 	node.e2di_mode = EXT2_IFREG | EXT2_RESIZEINOUMASK;
1081 	node.e2di_uid = geteuid();
1082 	node.e2di_atime = tv->tv_sec;
1083 	node.e2di_ctime = tv->tv_sec;
1084 	node.e2di_mtime = tv->tv_sec;
1085 	node.e2di_gid = getegid();
1086 	node.e2di_nlink = 1;
1087 
1088 	/*
1089 	 * To preserve the reserved group descriptor blocks,
1090 	 * EXT2_RESIZEINO uses only double indirect reference
1091 	 * blocks in its inode entries.
1092 	 *
1093 	 * All entries for direct, single indirect and triple
1094 	 * indirect references are left zero'ed. Maybe it's safe
1095 	 * because no write operation will happen with this inode.
1096 	 *
1097 	 * We have to allocate a block for the first level double
1098 	 * indirect reference block. Indexes of inode entries in
1099 	 * this first level dindirect block are corresponding to
1100 	 * indexes of group descriptors including both used (e2fs_ngdb)
1101 	 * and reserved (e2fs_reserved_ngdb) group descriptor blocks.
1102 	 *
1103 	 * Inode entries of indexes for used (e2fs_ngdb) descriptors are
1104 	 * left zero'ed. Entries for reserved (e2fs_reserved_ngdb) ones
1105 	 * have block numbers of actual reserved group descriptors
1106 	 * allocated at block group zero. This means e2fs_reserved_ngdb
1107 	 * blocks are reserved as the second level dindirect reference
1108 	 * blocks, and they actually contain block numbers of indirect
1109 	 * references. It may be safe since they don't have to keep any
1110 	 * data yet.
1111 	 *
1112 	 * Each these second dindirect blocks (i.e. reserved group
1113 	 * descriptor blocks in the first block group) should have
1114 	 * block numbers of its backups in all other block groups.
1115 	 * I.e. reserved_ngdb[0] block in block group 0 contains block
1116 	 * numbers of resreved_ngdb[0] from group 1 through (e2fs_ncg - 1).
1117 	 * The number of backups can be determined by the
1118 	 * EXT2_ROCOMPAT_SPARSESUPER feature and cg_has_sb() macro
1119 	 * as done in the above initcg() function.
1120 	 */
1121 
1122 	/* set e2di_size which occupies whole blocks through DINDIR blocks */
1123 	isize = (uint64_t)sblock.e2fs_bsize * NDADDR +
1124 	    (uint64_t)sblock.e2fs_bsize * NINDIR(&sblock) +
1125 	    (uint64_t)sblock.e2fs_bsize * NINDIR(&sblock) * NINDIR(&sblock);
1126 	if (isize > UINT32_MAX &&
1127 	    (sblock.e2fs.e2fs_features_rocompat &
1128 	     EXT2F_ROCOMPAT_LARGEFILE) == 0) {
1129 		/* XXX should enable it here and update all backups? */
1130 		errx(EXIT_FAILURE, "%s: large_file rocompat feature is "
1131 		    "required to enable resize feature for this filesystem\n",
1132 		    __func__);
1133 	}
1134 	/* upper 32bit is stored into e2di_dacl on REV1 feature */
1135 	node.e2di_size = isize & UINT32_MAX;
1136 	node.e2di_dacl = isize >> 32;
1137 
1138 #define SINGLE	0	/* index of single indirect block */
1139 #define DOUBLE	1	/* index of double indirect block */
1140 #define TRIPLE	2	/* index of triple indirect block */
1141 
1142 	/* zero out entries for direct references */
1143 	for (i = 0; i < NDADDR; i++)
1144 		node.e2di_blocks[i] = 0;
1145 	/* also zero out entries for single and triple indirect references */
1146 	node.e2di_blocks[NDADDR + SINGLE] = 0;
1147 	node.e2di_blocks[NDADDR + TRIPLE] = 0;
1148 
1149 	/* allocate a block for the first level double indirect reference */
1150 	node.e2di_blocks[NDADDR + DOUBLE] =
1151 	    alloc(sblock.e2fs_bsize, node.e2di_mode);
1152 	if (node.e2di_blocks[NDADDR + DOUBLE] == 0)
1153 		errx(EXIT_FAILURE, "%s: Can't allocate a dindirect block",
1154 		    __func__);
1155 
1156 	/* account this first block */
1157 	nblock = fsbtodb(&sblock, 1);
1158 
1159 	/* allocate buffer to set data in the dindirect block */
1160 	dindir_block = malloc(sblock.e2fs_bsize);
1161 	if (dindir_block == NULL)
1162 		errx(EXIT_FAILURE,
1163 		    "%s: Can't allocate buffer for a dindirect block",
1164 		    __func__);
1165 
1166 	/* allocate buffer to set data in the group descriptor blocks */
1167 	reserved_gdb = malloc(sblock.e2fs_bsize);
1168 	if (reserved_gdb == NULL)
1169 		errx(EXIT_FAILURE,
1170 		    "%s: Can't allocate buffer for group descriptor blocks",
1171 		    __func__);
1172 
1173 	/*
1174 	 * Setup block entries in the first level dindirect blocks
1175 	 */
1176 	for (i = 0; i < sblock.e2fs_ngdb; i++) {
1177 		/* no need to handle used group descriptor blocks */
1178 		dindir_block[i] = 0;
1179 	}
1180 	for (; i < sblock.e2fs_ngdb + sblock.e2fs.e2fs_reserved_ngdb; i++) {
1181 		/*
1182 		 * point reserved group descriptor block in the first
1183 		 * (i.e. master) block group
1184 		 *
1185 		 * XXX: e2fsprogs seem to use "(i % NINDIR(&sblock))" here
1186 		 *      to store maximum NINDIR(&sblock) reserved gdbs.
1187 		 *      I'm not sure what will be done on future filesystem
1188 		 *      shrink in that case on their way.
1189 		 */
1190 		if (i >= NINDIR(&sblock))
1191 			errx(EXIT_FAILURE, "%s: too many reserved "
1192 			    "group descriptors (%u) for resize inode",
1193 			    __func__, sblock.e2fs.e2fs_reserved_ngdb);
1194 		dindir_block[i] =
1195 		    h2fs32(cgbase(&sblock, 0) + NBLOCK_SUPERBLOCK + i);
1196 
1197 		/*
1198 		 * Setup block entries in the second dindirect blocks
1199 		 * (which are primary reserved group descriptor blocks)
1200 		 * to point their backups.
1201 		 */
1202 		for (n = 0, cylno = 1; cylno < sblock.e2fs_ncg; cylno++) {
1203 			/* skip block groups without backup */
1204 			if ((sblock.e2fs.e2fs_features_rocompat &
1205 			     EXT2F_ROCOMPAT_SPARSESUPER) != 0 &&
1206 			    cg_has_sb(cylno) == 0)
1207 				continue;
1208 
1209 			if (n >= NINDIR(&sblock))
1210 				errx(EXIT_FAILURE, "%s: too many block groups "
1211 				    "for the resize feature", __func__);
1212 			/*
1213 			 * These blocks are already reserved in
1214 			 * initcg() so no need to use alloc() here.
1215 			 */
1216 			reserved_gdb[n++] = h2fs32(cgbase(&sblock, cylno) +
1217 			    NBLOCK_SUPERBLOCK + i);
1218 			nblock += fsbtodb(&sblock, 1);
1219 		}
1220 		for (; n < NINDIR(&sblock); n++)
1221 			reserved_gdb[n] = 0;
1222 
1223 		/* write group descriptor block as the second dindirect refs */
1224 		wtfs(fsbtodb(&sblock, fs2h32(dindir_block[i])),
1225 		    sblock.e2fs_bsize, reserved_gdb);
1226 		nblock += fsbtodb(&sblock, 1);
1227 	}
1228 	for (; i < NINDIR(&sblock); i++) {
1229 		/* leave trailing entries unallocated */
1230 		dindir_block[i] = 0;
1231 	}
1232 	free(reserved_gdb);
1233 
1234 	/* finally write the first level dindirect block */
1235 	wtfs(fsbtodb(&sblock, node.e2di_blocks[NDADDR + DOUBLE]),
1236 	    sblock.e2fs_bsize, dindir_block);
1237 	free(dindir_block);
1238 
1239 	node.e2di_nblock = nblock;
1240 	iput(&node, EXT2_RESIZEINO);
1241 }
1242 
1243 /*
1244  * uint32_t alloc(uint32_t size, uint16_t mode)
1245  *
1246  *	Allocate a block (from cylinder group 0)
1247  *	Reference: src/sys/ufs/ext2fs/ext2fs_alloc.c:ext2fs_alloccg()
1248  */
1249 uint32_t
1250 alloc(uint32_t size, uint16_t mode)
1251 {
1252 	uint32_t loc, bno;
1253 	uint8_t *bbp;
1254 	uint len, map, i;
1255 
1256 	if (gd[0].ext2bgd_nbfree == 0)
1257 		return 0;
1258 
1259 	if (size > sblock.e2fs_bsize)
1260 		return 0;
1261 
1262 	bbp = malloc(sblock.e2fs_bsize);
1263 	if (bbp == NULL)
1264 		return 0;
1265 	rdfs(fsbtodb(&sblock, gd[0].ext2bgd_b_bitmap), sblock.e2fs_bsize, bbp);
1266 
1267 	/* XXX: kernel uses e2fs_fpg here */
1268 	len = sblock.e2fs.e2fs_bpg / NBBY;
1269 
1270 #if 0	/* no need block allocation for root or lost+found dir */
1271 	for (loc = 0; loc < len; loc++) {
1272 		if (bbp[loc] == 0) {
1273 			bno = loc * NBBY;
1274 			goto gotit;
1275 		}
1276 	}
1277 #endif
1278 
1279 	loc = skpc(~0U, len, bbp);
1280 	if (loc == 0)
1281 		return 0;
1282 	loc = len - loc;
1283 	map = bbp[loc];
1284 	bno = loc * NBBY;
1285 	for (i = 0; i < NBBY; i++, bno++) {
1286 		if ((map & (1 << i)) == 0)
1287 			goto gotit;
1288 	}
1289 	return 0;
1290 
1291  gotit:
1292 	if (isset(bbp, bno))
1293 		errx(EXIT_FAILURE, "%s: inconsistent bitmap\n", __func__);
1294 
1295 	setbit(bbp, bno);
1296 	wtfs(fsbtodb(&sblock, gd[0].ext2bgd_b_bitmap), sblock.e2fs_bsize, bbp);
1297 	free(bbp);
1298 	/* XXX: modified group descriptors won't be written into backups */
1299 	gd[0].ext2bgd_nbfree--;
1300 	if ((mode & EXT2_IFDIR) != 0)
1301 		gd[0].ext2bgd_ndirs++;
1302 	sblock.e2fs.e2fs_fbcount--;
1303 
1304 	return sblock.e2fs.e2fs_first_dblock + bno;
1305 }
1306 
1307 /*
1308  * void iput(struct ext2fs_dinode *ip, ino_t ino)
1309  *
1310  *	Put an inode entry into the corresponding table.
1311  */
1312 static void
1313 iput(struct ext2fs_dinode *ip, ino_t ino)
1314 {
1315 	daddr_t d;
1316 	uint c, i;
1317 	struct ext2fs_dinode *dp;
1318 	uint8_t *bp;
1319 
1320 	bp = malloc(sblock.e2fs_bsize);
1321 	if (bp == NULL)
1322 		errx(EXIT_FAILURE, "%s: can't allocate buffer for inode\n",
1323 		    __func__);
1324 
1325 	/*
1326 	 * Reserved inodes are allocated and accounted in initcg()
1327 	 * so skip checks of the bitmap and allocation for them.
1328 	 */
1329 	if (ino >= EXT2_FIRSTINO) {
1330 		c = ino_to_cg(&sblock, ino);
1331 
1332 		/* sanity check */
1333 		if (gd[c].ext2bgd_nifree == 0)
1334 			errx(EXIT_FAILURE,
1335 			    "%s: no free inode %" PRIu64 " in block group %u\n",
1336 			    __func__, (uint64_t)ino, c);
1337 
1338 		/* update inode bitmap */
1339 		rdfs(fsbtodb(&sblock, gd[0].ext2bgd_i_bitmap),
1340 		    sblock.e2fs_bsize, bp);
1341 
1342 		/* more sanity */
1343 		if (isset(bp, EXT2_INO_INDEX(ino)))
1344 			errx(EXIT_FAILURE, "%s: inode %" PRIu64
1345 			    " already in use\n", __func__, (uint64_t)ino);
1346 		setbit(bp, EXT2_INO_INDEX(ino));
1347 		wtfs(fsbtodb(&sblock, gd[0].ext2bgd_i_bitmap),
1348 		    sblock.e2fs_bsize, bp);
1349 		gd[c].ext2bgd_nifree--;
1350 		sblock.e2fs.e2fs_ficount--;
1351 	}
1352 
1353 	if (ino >= sblock.e2fs.e2fs_ipg * sblock.e2fs_ncg)
1354 		errx(EXIT_FAILURE, "%s: inode value out of range (%" PRIu64
1355 		    ").\n", __func__, (uint64_t)ino);
1356 
1357 	/* update an inode entry in the table */
1358 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
1359 	rdfs(d, sblock.e2fs_bsize, bp);
1360 
1361 	dp = (struct ext2fs_dinode *)(bp +
1362 	    inodesize * ino_to_fsbo(&sblock, ino));
1363 	e2fs_isave(ip, dp);
1364 	/* e2fs_i_bswap() doesn't swap e2di_blocks addrs */
1365 	if ((ip->e2di_mode & EXT2_IFMT) != EXT2_IFLNK) {
1366 		for (i = 0; i < NDADDR + NIADDR; i++)
1367 			dp->e2di_blocks[i] = h2fs32(ip->e2di_blocks[i]);
1368 	}
1369 	/* h2fs32() just for consistency */
1370 	dp->e2di_gen = h2fs32(arc4random());
1371 
1372 	wtfs(d, sblock.e2fs_bsize, bp);
1373 	free(bp);
1374 }
1375 
1376 /*
1377  * Read a block from the file system
1378  */
1379 void
1380 rdfs(daddr_t bno, int size, void *bf)
1381 {
1382 	int n;
1383 	off_t offset;
1384 
1385 	offset = bno;
1386 	n = pread(fsi, bf, size, offset * sectorsize);
1387 	if (n != size)
1388 		err(EXIT_FAILURE, "%s: read error for sector %" PRId64,
1389 		    __func__, (int64_t)bno);
1390 }
1391 
1392 /*
1393  * Write a block to the file system
1394  */
1395 void
1396 wtfs(daddr_t bno, int size, void *bf)
1397 {
1398 	int n;
1399 	off_t offset;
1400 
1401 	if (Nflag)
1402 		return;
1403 	offset = bno;
1404 	n = pwrite(fso, bf, size, offset * sectorsize);
1405 	if (n != size)
1406 		err(EXIT_FAILURE, "%s: write error for sector %" PRId64,
1407 		    __func__, (int64_t)bno);
1408 }
1409 
1410 int
1411 ilog2(uint val)
1412 {
1413 
1414 	if (val == 0 || !powerof2(val))
1415 		errx(EXIT_FAILURE, "%s: %u is not a power of 2\n",
1416 		    __func__, val);
1417 
1418 	return ffs(val) - 1;
1419 }
1420 
1421 /*
1422  * int skpc(int mask, size_t size, uint8_t *cp)
1423  *
1424  *	Locate an unsigned character of value mask inside cp[].
1425  * 	(from src/sys/lib/libkern/skpc.c)
1426  */
1427 int
1428 skpc(int mask, size_t size, uint8_t *cp)
1429 {
1430 	uint8_t *end;
1431 
1432 	end = &cp[size];
1433 	while (cp < end && *cp == (uint8_t)mask)
1434 		cp++;
1435 
1436 	return end - cp;
1437 }
1438