xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_vfsops.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /*	$NetBSD: ext2fs_vfsops.c,v 1.199 2016/08/14 11:44:54 jdolecek Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1991, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. 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  *	@(#)ffs_vfsops.c	8.14 (Berkeley) 11/28/94
32  * Modified for ext2fs by Manuel Bouyer.
33  */
34 
35 /*
36  * Copyright (c) 1997 Manuel Bouyer.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  *
47  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
48  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
49  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
50  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
51  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
52  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
53  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
54  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
55  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
56  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
57  *
58  *	@(#)ffs_vfsops.c	8.14 (Berkeley) 11/28/94
59  * Modified for ext2fs by Manuel Bouyer.
60  */
61 
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: ext2fs_vfsops.c,v 1.199 2016/08/14 11:44:54 jdolecek Exp $");
64 
65 #if defined(_KERNEL_OPT)
66 #include "opt_compat_netbsd.h"
67 #endif
68 
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/sysctl.h>
72 #include <sys/namei.h>
73 #include <sys/proc.h>
74 #include <sys/kernel.h>
75 #include <sys/vnode.h>
76 #include <sys/socket.h>
77 #include <sys/mount.h>
78 #include <sys/buf.h>
79 #include <sys/device.h>
80 #include <sys/mbuf.h>
81 #include <sys/file.h>
82 #include <sys/disklabel.h>
83 #include <sys/ioctl.h>
84 #include <sys/errno.h>
85 #include <sys/pool.h>
86 #include <sys/lock.h>
87 #include <sys/conf.h>
88 #include <sys/kauth.h>
89 #include <sys/module.h>
90 
91 #include <miscfs/genfs/genfs.h>
92 #include <miscfs/specfs/specdev.h>
93 
94 #include <ufs/ufs/quota.h>
95 #include <ufs/ufs/ufsmount.h>
96 #include <ufs/ufs/inode.h>
97 #include <ufs/ufs/dir.h>
98 #include <ufs/ufs/ufs_extern.h>
99 
100 #include <ufs/ext2fs/ext2fs.h>
101 #include <ufs/ext2fs/ext2fs_dir.h>
102 #include <ufs/ext2fs/ext2fs_extern.h>
103 
104 MODULE(MODULE_CLASS_VFS, ext2fs, "ffs");
105 
106 int ext2fs_sbupdate(struct ufsmount *, int);
107 static int ext2fs_sbfill(struct m_ext2fs *, int);
108 
109 static struct sysctllog *ext2fs_sysctl_log;
110 
111 extern const struct vnodeopv_desc ext2fs_vnodeop_opv_desc;
112 extern const struct vnodeopv_desc ext2fs_specop_opv_desc;
113 extern const struct vnodeopv_desc ext2fs_fifoop_opv_desc;
114 
115 const struct vnodeopv_desc * const ext2fs_vnodeopv_descs[] = {
116 	&ext2fs_vnodeop_opv_desc,
117 	&ext2fs_specop_opv_desc,
118 	&ext2fs_fifoop_opv_desc,
119 	NULL,
120 };
121 
122 struct vfsops ext2fs_vfsops = {
123 	.vfs_name = MOUNT_EXT2FS,
124 	.vfs_min_mount_data = sizeof (struct ufs_args),
125 	.vfs_mount = ext2fs_mount,
126 	.vfs_start = ufs_start,
127 	.vfs_unmount = ext2fs_unmount,
128 	.vfs_root = ufs_root,
129 	.vfs_quotactl = ufs_quotactl,
130 	.vfs_statvfs = ext2fs_statvfs,
131 	.vfs_sync = ext2fs_sync,
132 	.vfs_vget = ufs_vget,
133 	.vfs_loadvnode = ext2fs_loadvnode,
134 	.vfs_fhtovp = ext2fs_fhtovp,
135 	.vfs_vptofh = ext2fs_vptofh,
136 	.vfs_init = ext2fs_init,
137 	.vfs_reinit = ext2fs_reinit,
138 	.vfs_done = ext2fs_done,
139 	.vfs_mountroot = ext2fs_mountroot,
140 	.vfs_snapshot = (void *)eopnotsupp,
141 	.vfs_extattrctl = vfs_stdextattrctl,
142 	.vfs_suspendctl = (void *)eopnotsupp,
143 	.vfs_renamelock_enter = genfs_renamelock_enter,
144 	.vfs_renamelock_exit = genfs_renamelock_exit,
145 	.vfs_fsync = (void *)eopnotsupp,
146 	.vfs_opv_descs = ext2fs_vnodeopv_descs
147 };
148 
149 static const struct genfs_ops ext2fs_genfsops = {
150 	.gop_size = genfs_size,
151 	.gop_alloc = ext2fs_gop_alloc,
152 	.gop_write = genfs_gop_write,
153 	.gop_markupdate = ufs_gop_markupdate,
154 };
155 
156 static const struct ufs_ops ext2fs_ufsops = {
157 	.uo_itimes = ext2fs_itimes,
158 	.uo_update = ext2fs_update,
159 	.uo_bufrd = ext2fs_bufrd,
160 	.uo_bufwr = ext2fs_bufwr,
161 };
162 
163 /* Fill in the inode uid/gid from ext2 halves.  */
164 void
165 ext2fs_set_inode_guid(struct inode *ip)
166 {
167 
168 	ip->i_gid = ip->i_e2fs_gid;
169 	ip->i_uid = ip->i_e2fs_uid;
170 	if (ip->i_e2fs->e2fs.e2fs_rev > E2FS_REV0) {
171 		ip->i_gid |= ip->i_e2fs_gid_high << 16;
172 		ip->i_uid |= ip->i_e2fs_uid_high << 16;
173 	}
174 }
175 
176 static int
177 ext2fs_modcmd(modcmd_t cmd, void *arg)
178 {
179 	int error;
180 
181 	switch (cmd) {
182 	case MODULE_CMD_INIT:
183 		error = vfs_attach(&ext2fs_vfsops);
184 		if (error != 0)
185 			break;
186 		sysctl_createv(&ext2fs_sysctl_log, 0, NULL, NULL,
187 			       CTLFLAG_PERMANENT,
188 			       CTLTYPE_NODE, "ext2fs",
189 			       SYSCTL_DESCR("Linux EXT2FS file system"),
190 			       NULL, 0, NULL, 0,
191 			       CTL_VFS, 17, CTL_EOL);
192 		/*
193 		 * XXX the "17" above could be dynamic, thereby eliminating
194 		 * one more instance of the "number to vfs" mapping problem,
195 		 * but "17" is the order as taken from sys/mount.h
196 		 */
197 		break;
198 	case MODULE_CMD_FINI:
199 		error = vfs_detach(&ext2fs_vfsops);
200 		if (error != 0)
201 			break;
202 		sysctl_teardown(&ext2fs_sysctl_log);
203 		break;
204 	default:
205 		error = ENOTTY;
206 		break;
207 	}
208 
209 	return error;
210 }
211 
212 /*
213  * XXX Same structure as FFS inodes?  Should we share a common pool?
214  */
215 struct pool ext2fs_inode_pool;
216 
217 extern u_long ext2gennumber;
218 
219 void
220 ext2fs_init(void)
221 {
222 
223 	pool_init(&ext2fs_inode_pool, sizeof(struct inode), 0, 0, 0,
224 	    "ext2fsinopl", &pool_allocator_nointr, IPL_NONE);
225 	ufs_init();
226 }
227 
228 void
229 ext2fs_reinit(void)
230 {
231 	ufs_reinit();
232 }
233 
234 void
235 ext2fs_done(void)
236 {
237 
238 	ufs_done();
239 	pool_destroy(&ext2fs_inode_pool);
240 }
241 
242 /*
243  * Called by main() when ext2fs is going to be mounted as root.
244  *
245  * Name is updated by mount(8) after booting.
246  */
247 
248 int
249 ext2fs_mountroot(void)
250 {
251 	extern struct vnode *rootvp;
252 	struct m_ext2fs *fs;
253 	struct mount *mp;
254 	struct ufsmount *ump;
255 	int error;
256 
257 	if (device_class(root_device) != DV_DISK)
258 		return ENODEV;
259 
260 	if ((error = vfs_rootmountalloc(MOUNT_EXT2FS, "root_device", &mp))) {
261 		vrele(rootvp);
262 		return error;
263 	}
264 
265 	if ((error = ext2fs_mountfs(rootvp, mp)) != 0) {
266 		vfs_unbusy(mp, false, NULL);
267 		vfs_destroy(mp);
268 		return error;
269 	}
270 	mountlist_append(mp);
271 	ump = VFSTOUFS(mp);
272 	fs = ump->um_e2fs;
273 	memset(fs->e2fs_fsmnt, 0, sizeof(fs->e2fs_fsmnt));
274 	(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs_fsmnt,
275 	    sizeof(fs->e2fs_fsmnt) - 1, 0);
276 	if (fs->e2fs.e2fs_rev > E2FS_REV0) {
277 		memset(fs->e2fs.e2fs_fsmnt, 0, sizeof(fs->e2fs.e2fs_fsmnt));
278 		(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs.e2fs_fsmnt,
279 		    sizeof(fs->e2fs.e2fs_fsmnt) - 1, 0);
280 	}
281 	(void)ext2fs_statvfs(mp, &mp->mnt_stat);
282 	vfs_unbusy(mp, false, NULL);
283 	setrootfstime((time_t)fs->e2fs.e2fs_wtime);
284 	return 0;
285 }
286 
287 /*
288  * VFS Operations.
289  *
290  * mount system call
291  */
292 int
293 ext2fs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
294 {
295 	struct lwp *l = curlwp;
296 	struct vnode *devvp;
297 	struct ufs_args *args = data;
298 	struct ufsmount *ump = NULL;
299 	struct m_ext2fs *fs;
300 	size_t size;
301 	int error = 0, flags, update;
302 	mode_t accessmode;
303 
304 	if (args == NULL)
305 		return EINVAL;
306 	if (*data_len < sizeof *args)
307 		return EINVAL;
308 
309 	if (mp->mnt_flag & MNT_GETARGS) {
310 		ump = VFSTOUFS(mp);
311 		if (ump == NULL)
312 			return EIO;
313 		memset(args, 0, sizeof *args);
314 		args->fspec = NULL;
315 		*data_len = sizeof *args;
316 		return 0;
317 	}
318 
319 	update = mp->mnt_flag & MNT_UPDATE;
320 
321 	/* Check arguments */
322 	if (args->fspec != NULL) {
323 		/*
324 		 * Look up the name and verify that it's sane.
325 		 */
326 		error = namei_simple_user(args->fspec,
327 					NSM_FOLLOW_NOEMULROOT, &devvp);
328 		if (error != 0)
329 			return error;
330 
331 		if (!update) {
332 			/*
333 			 * Be sure this is a valid block device
334 			 */
335 			if (devvp->v_type != VBLK)
336 				error = ENOTBLK;
337 			else if (bdevsw_lookup(devvp->v_rdev) == NULL)
338 				error = ENXIO;
339 		} else {
340 		        /*
341 			 * Be sure we're still naming the same device
342 			 * used for our initial mount
343 			 */
344 			ump = VFSTOUFS(mp);
345 			if (devvp != ump->um_devvp) {
346 				if (devvp->v_rdev != ump->um_devvp->v_rdev)
347 					error = EINVAL;
348 				else {
349 					vrele(devvp);
350 					devvp = ump->um_devvp;
351 					vref(devvp);
352 				}
353 			}
354 		}
355 	} else {
356 		if (!update) {
357 			/* New mounts must have a filename for the device */
358 			return EINVAL;
359 		} else {
360 			ump = VFSTOUFS(mp);
361 			devvp = ump->um_devvp;
362 			vref(devvp);
363 		}
364 	}
365 
366 	/*
367 	 * If mount by non-root, then verify that user has necessary
368 	 * permissions on the device.
369 	 *
370 	 * Permission to update a mount is checked higher, so here we presume
371 	 * updating the mount is okay (for example, as far as securelevel goes)
372 	 * which leaves us with the normal check.
373 	 */
374 	if (error == 0) {
375 		accessmode = VREAD;
376 		if (update ?
377 		    (mp->mnt_iflag & IMNT_WANTRDWR) != 0 :
378 		    (mp->mnt_flag & MNT_RDONLY) == 0)
379 			accessmode |= VWRITE;
380 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
381 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
382 		    KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp,
383 		    KAUTH_ARG(accessmode));
384 		VOP_UNLOCK(devvp);
385 	}
386 
387 	if (error) {
388 		vrele(devvp);
389 		return error;
390 	}
391 
392 	if (!update) {
393 		int xflags;
394 
395 		if (mp->mnt_flag & MNT_RDONLY)
396 			xflags = FREAD;
397 		else
398 			xflags = FREAD|FWRITE;
399 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
400 		error = VOP_OPEN(devvp, xflags, FSCRED);
401 		VOP_UNLOCK(devvp);
402 		if (error)
403 			goto fail;
404 		error = ext2fs_mountfs(devvp, mp);
405 		if (error) {
406 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
407 			(void)VOP_CLOSE(devvp, xflags, NOCRED);
408 			VOP_UNLOCK(devvp);
409 			goto fail;
410 		}
411 
412 		ump = VFSTOUFS(mp);
413 		fs = ump->um_e2fs;
414 	} else {
415 		/*
416 		 * Update the mount.
417 		 */
418 
419 		/*
420 		 * The initial mount got a reference on this
421 		 * device, so drop the one obtained via
422 		 * namei(), above.
423 		 */
424 		vrele(devvp);
425 
426 		ump = VFSTOUFS(mp);
427 		fs = ump->um_e2fs;
428 		if (fs->e2fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
429 			/*
430 			 * Changing from r/w to r/o
431 			 */
432 			flags = WRITECLOSE;
433 			if (mp->mnt_flag & MNT_FORCE)
434 				flags |= FORCECLOSE;
435 			error = ext2fs_flushfiles(mp, flags);
436 			if (error == 0 &&
437 			    ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
438 			    (fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
439 				fs->e2fs.e2fs_state = E2FS_ISCLEAN;
440 				(void) ext2fs_sbupdate(ump, MNT_WAIT);
441 			}
442 			if (error)
443 				return error;
444 			fs->e2fs_ronly = 1;
445 		}
446 
447 		if (mp->mnt_flag & MNT_RELOAD) {
448 			error = ext2fs_reload(mp, l->l_cred, l);
449 			if (error)
450 				return error;
451 		}
452 
453 		if (fs->e2fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) {
454 			/*
455 			 * Changing from read-only to read/write
456 			 */
457 			fs->e2fs_ronly = 0;
458 			if (fs->e2fs.e2fs_state == E2FS_ISCLEAN)
459 				fs->e2fs.e2fs_state = 0;
460 			else
461 				fs->e2fs.e2fs_state = E2FS_ERRORS;
462 			fs->e2fs_fmod = 1;
463 		}
464 		if (args->fspec == NULL)
465 			return 0;
466 	}
467 
468 	error = set_statvfs_info(path, UIO_USERSPACE, args->fspec,
469 	    UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
470 	(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs_fsmnt,
471 	    sizeof(fs->e2fs_fsmnt) - 1, &size);
472 	memset(fs->e2fs_fsmnt + size, 0, sizeof(fs->e2fs_fsmnt) - size);
473 	if (fs->e2fs.e2fs_rev > E2FS_REV0) {
474 		(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs.e2fs_fsmnt,
475 		    sizeof(fs->e2fs.e2fs_fsmnt) - 1, &size);
476 		memset(fs->e2fs.e2fs_fsmnt, 0,
477 		    sizeof(fs->e2fs.e2fs_fsmnt) - size);
478 	}
479 	if (fs->e2fs_fmod != 0) {	/* XXX */
480 		fs->e2fs_fmod = 0;
481 		if (fs->e2fs.e2fs_state == 0)
482 			fs->e2fs.e2fs_wtime = time_second;
483 		else
484 			printf("%s: file system not clean; please fsck(8)\n",
485 				mp->mnt_stat.f_mntfromname);
486 		(void) ext2fs_cgupdate(ump, MNT_WAIT);
487 	}
488 	return error;
489 
490 fail:
491 	vrele(devvp);
492 	return error;
493 }
494 
495 /*
496  *
497  */
498 static int
499 ext2fs_loadvnode_content(struct m_ext2fs *fs, ino_t ino, struct buf *bp, struct inode *ip)
500 {
501 	struct ext2fs_dinode *din;
502 	void *cp;
503 	int error = 0;
504 
505 	cp = (char *)bp->b_data + (ino_to_fsbo(fs, ino) * EXT2_DINODE_SIZE(fs));
506 	din = kmem_alloc(EXT2_DINODE_SIZE(fs), KM_SLEEP);
507 	e2fs_iload((struct ext2fs_dinode *)cp, din, EXT2_DINODE_SIZE(fs));
508 
509 	/* sanity checks */
510 	if (EXT2_DINODE_FITS(din, e2di_extra_isize, EXT2_DINODE_SIZE(fs))
511 	    && (EXT2_DINODE_SIZE(fs) - EXT2_REV0_DINODE_SIZE) < din->e2di_extra_isize)
512 	{
513 		printf("ext2fs: inode %"PRIu64" bad extra_isize %u",
514 			ino, din->e2di_extra_isize);
515 		error = EINVAL;
516 		goto bad;
517 	}
518 
519 	/* replace old dinode; assumes new dinode size is same as old one */
520 	if (ip->i_din.e2fs_din)
521 		kmem_free(ip->i_din.e2fs_din, EXT2_DINODE_SIZE(fs));
522 	ip->i_din.e2fs_din = din;
523 
524 	ext2fs_set_inode_guid(ip);
525 	return error;
526 
527     bad:
528 	kmem_free(din, EXT2_DINODE_SIZE(fs));
529 	return error;
530 }
531 
532 /*
533  * Reload all incore data for a filesystem (used after running fsck on
534  * the root filesystem and finding things to fix). The filesystem must
535  * be mounted read-only.
536  *
537  * Things to do to update the mount:
538  *	1) invalidate all cached meta-data.
539  *	2) re-read superblock from disk.
540  *	3) re-read summary information from disk.
541  *	4) invalidate all inactive vnodes.
542  *	5) invalidate all cached file data.
543  *	6) re-read inode data for all active vnodes.
544  */
545 int
546 ext2fs_reload(struct mount *mp, kauth_cred_t cred, struct lwp *l)
547 {
548 	struct vnode *vp, *devvp;
549 	struct inode *ip;
550 	struct buf *bp;
551 	struct m_ext2fs *fs;
552 	struct ext2fs *newfs;
553 	int i, error;
554 	struct ufsmount *ump;
555 	struct vnode_iterator *marker;
556 
557 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
558 		return EINVAL;
559 
560 	ump = VFSTOUFS(mp);
561 	/*
562 	 * Step 1: invalidate all cached meta-data.
563 	 */
564 	devvp = ump->um_devvp;
565 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
566 	error = vinvalbuf(devvp, 0, cred, l, 0, 0);
567 	VOP_UNLOCK(devvp);
568 	if (error)
569 		panic("ext2fs_reload: dirty1");
570 
571 	fs = ump->um_e2fs;
572 	/*
573 	 * Step 2: re-read superblock from disk. Copy in new superblock, and compute
574 	 * in-memory values.
575 	 */
576 	error = bread(devvp, SBLOCK, SBSIZE, 0, &bp);
577 	if (error)
578 		return error;
579 	newfs = (struct ext2fs *)bp->b_data;
580 	e2fs_sbload(newfs, &fs->e2fs);
581 
582 	brelse(bp, 0);
583 
584 	error = ext2fs_sbfill(fs, (mp->mnt_flag & MNT_RDONLY) != 0);
585 	if (error)
586 		return error;
587 
588 	/*
589 	 * Step 3: re-read summary information from disk.
590 	 */
591 	for (i = 0; i < fs->e2fs_ngdb; i++) {
592 		error = bread(devvp ,
593 		    EXT2_FSBTODB(fs, fs->e2fs.e2fs_first_dblock +
594 		    1 /* superblock */ + i),
595 		    fs->e2fs_bsize, 0, &bp);
596 		if (error) {
597 			return error;
598 		}
599 		e2fs_cgload((struct ext2_gd *)bp->b_data,
600 		    &fs->e2fs_gd[i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
601 		    fs->e2fs_bsize);
602 		brelse(bp, 0);
603 	}
604 
605 	vfs_vnode_iterator_init(mp, &marker);
606 	while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL))) {
607 		/*
608 		 * Step 4: invalidate all inactive vnodes.
609 		 */
610 		if (vrecycle(vp))
611 			continue;
612 		/*
613 		 * Step 5: invalidate all cached file data.
614 		 */
615 		if (vn_lock(vp, LK_EXCLUSIVE)) {
616 			vrele(vp);
617 			continue;
618 		}
619 		if (vinvalbuf(vp, 0, cred, l, 0, 0))
620 			panic("ext2fs_reload: dirty2");
621 		/*
622 		 * Step 6: re-read inode data for all active vnodes.
623 		 */
624 		ip = VTOI(vp);
625 		error = bread(devvp, EXT2_FSBTODB(fs, ino_to_fsba(fs, ip->i_number)),
626 		    (int)fs->e2fs_bsize, 0, &bp);
627 		if (error) {
628 			vput(vp);
629 			break;
630 		}
631 		error = ext2fs_loadvnode_content(fs, ip->i_number, bp, ip);
632 		brelse(bp, 0);
633 		if (error) {
634 			vput(vp);
635 			break;
636 		}
637 
638 		vput(vp);
639 	}
640 	vfs_vnode_iterator_destroy(marker);
641 	return error;
642 }
643 
644 /*
645  * Common code for mount and mountroot
646  */
647 int
648 ext2fs_mountfs(struct vnode *devvp, struct mount *mp)
649 {
650 	struct lwp *l = curlwp;
651 	struct ufsmount *ump;
652 	struct buf *bp;
653 	struct ext2fs *fs;
654 	struct m_ext2fs *m_fs;
655 	dev_t dev;
656 	int error, i, ronly;
657 	kauth_cred_t cred;
658 
659 	dev = devvp->v_rdev;
660 	cred = l->l_cred;
661 
662 	/* Flush out any old buffers remaining from a previous use. */
663 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
664 	error = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0);
665 	VOP_UNLOCK(devvp);
666 	if (error)
667 		return error;
668 
669 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
670 
671 	bp = NULL;
672 	ump = NULL;
673 
674 	/* Read the superblock from disk, and swap it directly. */
675 	error = bread(devvp, SBLOCK, SBSIZE, 0, &bp);
676 	if (error)
677 		goto out;
678 	fs = (struct ext2fs *)bp->b_data;
679 	m_fs = kmem_zalloc(sizeof(struct m_ext2fs), KM_SLEEP);
680 	e2fs_sbload(fs, &m_fs->e2fs);
681 
682 	brelse(bp, 0);
683 	bp = NULL;
684 
685 	/* Once swapped, validate and fill in the superblock. */
686 	error = ext2fs_sbfill(m_fs, ronly);
687 	if (error) {
688 		kmem_free(m_fs, sizeof(struct m_ext2fs));
689 		goto out;
690 	}
691 	m_fs->e2fs_ronly = ronly;
692 
693 	ump = kmem_zalloc(sizeof(*ump), KM_SLEEP);
694 	ump->um_fstype = UFS1;
695 	ump->um_ops = &ext2fs_ufsops;
696 	ump->um_e2fs = m_fs;
697 
698 	if (ronly == 0) {
699 		if (m_fs->e2fs.e2fs_state == E2FS_ISCLEAN)
700 			m_fs->e2fs.e2fs_state = 0;
701 		else
702 			m_fs->e2fs.e2fs_state = E2FS_ERRORS;
703 		m_fs->e2fs_fmod = 1;
704 	}
705 
706 	/* XXX: should be added in ext2fs_sbfill()? */
707 	m_fs->e2fs_gd = kmem_alloc(m_fs->e2fs_ngdb * m_fs->e2fs_bsize, KM_SLEEP);
708 	for (i = 0; i < m_fs->e2fs_ngdb; i++) {
709 		error = bread(devvp,
710 		    EXT2_FSBTODB(m_fs, m_fs->e2fs.e2fs_first_dblock +
711 		    1 /* superblock */ + i),
712 		    m_fs->e2fs_bsize, 0, &bp);
713 		if (error) {
714 			kmem_free(m_fs->e2fs_gd,
715 			    m_fs->e2fs_ngdb * m_fs->e2fs_bsize);
716 			goto out;
717 		}
718 		e2fs_cgload((struct ext2_gd *)bp->b_data,
719 		    &m_fs->e2fs_gd[
720 			i * m_fs->e2fs_bsize / sizeof(struct ext2_gd)],
721 		    m_fs->e2fs_bsize);
722 		brelse(bp, 0);
723 		bp = NULL;
724 	}
725 
726 	mp->mnt_data = ump;
727 	mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
728 	mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_EXT2FS);
729 	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
730 	mp->mnt_stat.f_namemax = EXT2FS_MAXNAMLEN;
731 	mp->mnt_flag |= MNT_LOCAL;
732 	mp->mnt_dev_bshift = DEV_BSHIFT;	/* XXX */
733 	mp->mnt_fs_bshift = m_fs->e2fs_bshift;
734 	mp->mnt_iflag |= IMNT_DTYPE;
735 	ump->um_flags = 0;
736 	ump->um_mountp = mp;
737 	ump->um_dev = dev;
738 	ump->um_devvp = devvp;
739 	ump->um_nindir = EXT2_NINDIR(m_fs);
740 	ump->um_lognindir = ffs(EXT2_NINDIR(m_fs)) - 1;
741 	ump->um_bptrtodb = m_fs->e2fs_fsbtodb;
742 	ump->um_seqinc = 1; /* no frags */
743 	ump->um_maxsymlinklen = EXT2_MAXSYMLINKLEN;
744 	ump->um_dirblksiz = m_fs->e2fs_bsize;
745 	ump->um_maxfilesize = ((uint64_t)0x80000000 * m_fs->e2fs_bsize - 1);
746 	spec_node_setmountedfs(devvp, mp);
747 	return 0;
748 
749 out:
750 	if (bp != NULL)
751 		brelse(bp, 0);
752 	if (ump) {
753 		kmem_free(ump->um_e2fs, sizeof(struct m_ext2fs));
754 		kmem_free(ump, sizeof(*ump));
755 		mp->mnt_data = NULL;
756 	}
757 	return error;
758 }
759 
760 /*
761  * unmount system call
762  */
763 int
764 ext2fs_unmount(struct mount *mp, int mntflags)
765 {
766 	struct ufsmount *ump;
767 	struct m_ext2fs *fs;
768 	int error, flags;
769 
770 	flags = 0;
771 	if (mntflags & MNT_FORCE)
772 		flags |= FORCECLOSE;
773 	if ((error = ext2fs_flushfiles(mp, flags)) != 0)
774 		return error;
775 	ump = VFSTOUFS(mp);
776 	fs = ump->um_e2fs;
777 	if (fs->e2fs_ronly == 0 &&
778 		ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
779 		(fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
780 		fs->e2fs.e2fs_state = E2FS_ISCLEAN;
781 		(void) ext2fs_sbupdate(ump, MNT_WAIT);
782 	}
783 	if (ump->um_devvp->v_type != VBAD)
784 		spec_node_setmountedfs(ump->um_devvp, NULL);
785 	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
786 	error = VOP_CLOSE(ump->um_devvp, fs->e2fs_ronly ? FREAD : FREAD|FWRITE,
787 	    NOCRED);
788 	vput(ump->um_devvp);
789 	kmem_free(fs->e2fs_gd, fs->e2fs_ngdb * fs->e2fs_bsize);
790 	kmem_free(fs, sizeof(*fs));
791 	kmem_free(ump, sizeof(*ump));
792 	mp->mnt_data = NULL;
793 	mp->mnt_flag &= ~MNT_LOCAL;
794 	return error;
795 }
796 
797 /*
798  * Flush out all the files in a filesystem.
799  */
800 int
801 ext2fs_flushfiles(struct mount *mp, int flags)
802 {
803 	extern int doforce;
804 	int error;
805 
806 	if (!doforce)
807 		flags &= ~FORCECLOSE;
808 	error = vflush(mp, NULLVP, flags);
809 	return error;
810 }
811 
812 /*
813  * Get file system statistics.
814  */
815 int
816 ext2fs_statvfs(struct mount *mp, struct statvfs *sbp)
817 {
818 	struct ufsmount *ump;
819 	struct m_ext2fs *fs;
820 	uint32_t overhead, overhead_per_group, ngdb;
821 	int i, ngroups;
822 
823 	ump = VFSTOUFS(mp);
824 	fs = ump->um_e2fs;
825 	if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
826 		panic("ext2fs_statvfs");
827 
828 	/*
829 	 * Compute the overhead (FS structures)
830 	 */
831 	overhead_per_group =
832 	    1 /* block bitmap */ +
833 	    1 /* inode bitmap */ +
834 	    fs->e2fs_itpg;
835 	overhead = fs->e2fs.e2fs_first_dblock +
836 	    fs->e2fs_ncg * overhead_per_group;
837 	if (EXT2F_HAS_ROCOMPAT_FEATURE(fs, EXT2F_ROCOMPAT_SPARSESUPER)) {
838 		for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
839 			if (cg_has_sb(i))
840 				ngroups++;
841 		}
842 	} else {
843 		ngroups = fs->e2fs_ncg;
844 	}
845 	ngdb = fs->e2fs_ngdb;
846 	if (EXT2F_HAS_COMPAT_FEATURE(fs, EXT2F_COMPAT_RESIZE))
847 		ngdb += fs->e2fs.e2fs_reserved_ngdb;
848 	overhead += ngroups * (1 /* superblock */ + ngdb);
849 
850 	sbp->f_bsize = fs->e2fs_bsize;
851 	sbp->f_frsize = MINBSIZE << fs->e2fs.e2fs_fsize;
852 	sbp->f_iosize = fs->e2fs_bsize;
853 	sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
854 	sbp->f_bfree = fs->e2fs.e2fs_fbcount;
855 	sbp->f_bresvd = fs->e2fs.e2fs_rbcount;
856 	if (sbp->f_bfree > sbp->f_bresvd)
857 		sbp->f_bavail = sbp->f_bfree - sbp->f_bresvd;
858 	else
859 		sbp->f_bavail = 0;
860 	sbp->f_files =  fs->e2fs.e2fs_icount;
861 	sbp->f_ffree = fs->e2fs.e2fs_ficount;
862 	sbp->f_favail = fs->e2fs.e2fs_ficount;
863 	sbp->f_fresvd = 0;
864 	copy_statvfs_info(sbp, mp);
865 	return 0;
866 }
867 
868 static bool
869 ext2fs_sync_selector(void *cl, struct vnode *vp)
870 {
871 	struct inode *ip;
872 
873 	ip = VTOI(vp);
874 	/*
875 	 * Skip the vnode/inode if inaccessible.
876 	 */
877 	if (ip == NULL || vp->v_type == VNON)
878 		return false;
879 
880 	if (((ip->i_flag &
881 	      (IN_CHANGE | IN_UPDATE | IN_MODIFIED)) == 0 &&
882 	     LIST_EMPTY(&vp->v_dirtyblkhd) &&
883 	     UVM_OBJ_IS_CLEAN(&vp->v_uobj)))
884 		return false;
885 	return true;
886 }
887 
888 /*
889  * Go through the disk queues to initiate sandbagged IO;
890  * go through the inodes to write those that have been modified;
891  * initiate the writing of the super block if it has been modified.
892  *
893  * Note: we are always called with the filesystem marked `MPBUSY'.
894  */
895 int
896 ext2fs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
897 {
898 	struct vnode *vp;
899 	struct ufsmount *ump = VFSTOUFS(mp);
900 	struct m_ext2fs *fs;
901 	struct vnode_iterator *marker;
902 	int error, allerror = 0;
903 
904 	fs = ump->um_e2fs;
905 	if (fs->e2fs_fmod != 0 && fs->e2fs_ronly != 0) {	/* XXX */
906 		printf("fs = %s\n", fs->e2fs_fsmnt);
907 		panic("update: rofs mod");
908 	}
909 
910 	/*
911 	 * Write back each (modified) inode.
912 	 */
913 	vfs_vnode_iterator_init(mp, &marker);
914 	while ((vp = vfs_vnode_iterator_next(marker, ext2fs_sync_selector,
915 	    NULL)))
916 	{
917 		error = vn_lock(vp, LK_EXCLUSIVE);
918 		if (error) {
919 			vrele(vp);
920 			continue;
921 		}
922 		if (vp->v_type == VREG && waitfor == MNT_LAZY)
923 			error = ext2fs_update(vp, NULL, NULL, 0);
924 		else
925 			error = VOP_FSYNC(vp, cred,
926 			    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0);
927 		if (error)
928 			allerror = error;
929 		vput(vp);
930 	}
931 	vfs_vnode_iterator_destroy(marker);
932 	/*
933 	 * Force stale file system control information to be flushed.
934 	 */
935 	if (waitfor != MNT_LAZY) {
936 		vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
937 		if ((error = VOP_FSYNC(ump->um_devvp, cred,
938 		    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
939 			allerror = error;
940 		VOP_UNLOCK(ump->um_devvp);
941 	}
942 	/*
943 	 * Write back modified superblock.
944 	 */
945 	if (fs->e2fs_fmod != 0) {
946 		fs->e2fs_fmod = 0;
947 		fs->e2fs.e2fs_wtime = time_second;
948 		if ((error = ext2fs_cgupdate(ump, waitfor)))
949 			allerror = error;
950 	}
951 	return allerror;
952 }
953 
954 /*
955  * Read an inode from disk and initialize this vnode / inode pair.
956  * Caller assures no other thread will try to load this inode.
957  */
958 int
959 ext2fs_loadvnode(struct mount *mp, struct vnode *vp,
960     const void *key, size_t key_len, const void **new_key)
961 {
962 	ino_t ino;
963 	struct m_ext2fs *fs;
964 	struct inode *ip;
965 	struct ufsmount *ump;
966 	struct buf *bp;
967 	dev_t dev;
968 	int error;
969 
970 	KASSERT(key_len == sizeof(ino));
971 	memcpy(&ino, key, key_len);
972 	ump = VFSTOUFS(mp);
973 	dev = ump->um_dev;
974 	fs = ump->um_e2fs;
975 
976 	/* Read in the disk contents for the inode, copy into the inode. */
977 	error = bread(ump->um_devvp, EXT2_FSBTODB(fs, ino_to_fsba(fs, ino)),
978 	    (int)fs->e2fs_bsize, 0, &bp);
979 	if (error)
980 		return error;
981 
982 	/* Allocate and initialize inode. */
983 	ip = pool_get(&ext2fs_inode_pool, PR_WAITOK);
984 	memset(ip, 0, sizeof(struct inode));
985 	vp->v_tag = VT_EXT2FS;
986 	vp->v_op = ext2fs_vnodeop_p;
987 	vp->v_vflag |= VV_LOCKSWORK;
988 	vp->v_data = ip;
989 	ip->i_vnode = vp;
990 	ip->i_ump = ump;
991 	ip->i_e2fs = fs;
992 	ip->i_dev = dev;
993 	ip->i_number = ino;
994 	ip->i_e2fs_last_lblk = 0;
995 	ip->i_e2fs_last_blk = 0;
996 
997 	/* Initialize genfs node. */
998 	genfs_node_init(vp, &ext2fs_genfsops);
999 
1000 	error = ext2fs_loadvnode_content(fs, ino, bp, ip);
1001 	brelse(bp, 0);
1002 	if (error)
1003 		return error;
1004 
1005 	/* If the inode was deleted, reset all fields */
1006 	if (ip->i_e2fs_dtime != 0) {
1007 		ip->i_e2fs_mode = 0;
1008 		(void)ext2fs_setsize(ip, 0);
1009 		(void)ext2fs_setnblock(ip, 0);
1010 		memset(ip->i_e2fs_blocks, 0, sizeof(ip->i_e2fs_blocks));
1011 	}
1012 
1013 	/* Initialize the vnode from the inode. */
1014 	ext2fs_vinit(mp, ext2fs_specop_p, ext2fs_fifoop_p, &vp);
1015 
1016 	/* Finish inode initialization. */
1017 	ip->i_devvp = ump->um_devvp;
1018 	vref(ip->i_devvp);
1019 
1020 	/*
1021 	 * Set up a generation number for this inode if it does not
1022 	 * already have one. This should only happen on old filesystems.
1023 	 */
1024 
1025 	if (ip->i_e2fs_gen == 0) {
1026 		if (++ext2gennumber < (u_long)time_second)
1027 			ext2gennumber = time_second;
1028 		ip->i_e2fs_gen = ext2gennumber;
1029 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
1030 			ip->i_flag |= IN_MODIFIED;
1031 	}
1032 	uvm_vnp_setsize(vp, ext2fs_size(ip));
1033 	*new_key = &ip->i_number;
1034 	return 0;
1035 }
1036 
1037 /*
1038  * File handle to vnode
1039  *
1040  * Have to be really careful about stale file handles:
1041  * - check that the inode number is valid
1042  * - call ext2fs_vget() to get the locked inode
1043  * - check for an unallocated inode (i_mode == 0)
1044  */
1045 int
1046 ext2fs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
1047 {
1048 	struct inode *ip;
1049 	struct vnode *nvp;
1050 	int error;
1051 	struct ufid ufh;
1052 	struct m_ext2fs *fs;
1053 
1054 	if (fhp->fid_len != sizeof(struct ufid))
1055 		return EINVAL;
1056 
1057 	memcpy(&ufh, fhp, sizeof(struct ufid));
1058 	fs = VFSTOUFS(mp)->um_e2fs;
1059 	if ((ufh.ufid_ino < EXT2_FIRSTINO && ufh.ufid_ino != EXT2_ROOTINO) ||
1060 		ufh.ufid_ino >= fs->e2fs_ncg * fs->e2fs.e2fs_ipg)
1061 		return ESTALE;
1062 
1063 	if ((error = VFS_VGET(mp, ufh.ufid_ino, &nvp)) != 0) {
1064 		*vpp = NULLVP;
1065 		return error;
1066 	}
1067 	ip = VTOI(nvp);
1068 	if (ip->i_e2fs_mode == 0 || ip->i_e2fs_dtime != 0 ||
1069 		ip->i_e2fs_gen != ufh.ufid_gen) {
1070 		vput(nvp);
1071 		*vpp = NULLVP;
1072 		return ESTALE;
1073 	}
1074 	*vpp = nvp;
1075 	return 0;
1076 }
1077 
1078 /*
1079  * Vnode pointer to File handle
1080  */
1081 /* ARGSUSED */
1082 int
1083 ext2fs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
1084 {
1085 	struct inode *ip;
1086 	struct ufid ufh;
1087 
1088 	if (*fh_size < sizeof(struct ufid)) {
1089 		*fh_size = sizeof(struct ufid);
1090 		return E2BIG;
1091 	}
1092 	*fh_size = sizeof(struct ufid);
1093 
1094 	ip = VTOI(vp);
1095 	memset(&ufh, 0, sizeof(ufh));
1096 	ufh.ufid_len = sizeof(struct ufid);
1097 	ufh.ufid_ino = ip->i_number;
1098 	ufh.ufid_gen = ip->i_e2fs_gen;
1099 	memcpy(fhp, &ufh, sizeof(ufh));
1100 	return 0;
1101 }
1102 
1103 /*
1104  * Write a superblock and associated information back to disk.
1105  */
1106 int
1107 ext2fs_sbupdate(struct ufsmount *mp, int waitfor)
1108 {
1109 	struct m_ext2fs *fs = mp->um_e2fs;
1110 	struct buf *bp;
1111 	int error = 0;
1112 
1113 	bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, 0);
1114 	e2fs_sbsave(&fs->e2fs, (struct ext2fs*)bp->b_data);
1115 	if (waitfor == MNT_WAIT)
1116 		error = bwrite(bp);
1117 	else
1118 		bawrite(bp);
1119 	return error;
1120 }
1121 
1122 int
1123 ext2fs_cgupdate(struct ufsmount *mp, int waitfor)
1124 {
1125 	struct m_ext2fs *fs = mp->um_e2fs;
1126 	struct buf *bp;
1127 	int i, error = 0, allerror = 0;
1128 
1129 	allerror = ext2fs_sbupdate(mp, waitfor);
1130 	for (i = 0; i < fs->e2fs_ngdb; i++) {
1131 		bp = getblk(mp->um_devvp, EXT2_FSBTODB(fs,
1132 		    fs->e2fs.e2fs_first_dblock +
1133 		    1 /* superblock */ + i), fs->e2fs_bsize, 0, 0);
1134 		e2fs_cgsave(&fs->e2fs_gd[
1135 		    i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
1136 		    (struct ext2_gd *)bp->b_data, fs->e2fs_bsize);
1137 		if (waitfor == MNT_WAIT)
1138 			error = bwrite(bp);
1139 		else
1140 			bawrite(bp);
1141 	}
1142 
1143 	if (!allerror && error)
1144 		allerror = error;
1145 	return allerror;
1146 }
1147 
1148 /*
1149  * Fill in the m_fs structure, and validate the fields of the superblock.
1150  * NOTE: here, the superblock is already swapped.
1151  */
1152 static int
1153 ext2fs_sbfill(struct m_ext2fs *m_fs, int ronly)
1154 {
1155 	uint32_t u32;
1156 	struct ext2fs *fs = &m_fs->e2fs;
1157 
1158 	/*
1159 	 * General sanity checks
1160 	 */
1161 	if (fs->e2fs_magic != E2FS_MAGIC)
1162 		return EINVAL;
1163 	if (fs->e2fs_rev > E2FS_REV1) {
1164 		printf("ext2fs: unsupported revision number: %x\n", fs->e2fs_rev);
1165 		return EINVAL;
1166 	}
1167 	if (fs->e2fs_log_bsize > 2) {
1168 		/* block size = 1024|2048|4096 */
1169 		printf("ext2fs: bad block size: %d\n", fs->e2fs_log_bsize);
1170 		return EINVAL;
1171 	}
1172 	if (fs->e2fs_bpg == 0) {
1173 		printf("ext2fs: zero blocks per group\n");
1174 		return EINVAL;
1175 	}
1176 	if (fs->e2fs_ipg == 0) {
1177 		printf("ext2fs: zero inodes per group\n");
1178 		return EINVAL;
1179 	}
1180 
1181 	if (fs->e2fs_first_dblock >= fs->e2fs_bcount) {
1182 		printf("ext2fs: invalid first data block\n");
1183 		return EINVAL;
1184 	}
1185 	if (fs->e2fs_rbcount > fs->e2fs_bcount ||
1186 	    fs->e2fs_fbcount > fs->e2fs_bcount) {
1187 		printf("ext2fs: invalid block count\n");
1188 		return EINVAL;
1189 	}
1190 
1191 	/*
1192 	 * Compute the fields of the superblock
1193 	 */
1194 	u32 = fs->e2fs_bcount - fs->e2fs_first_dblock; /* > 0 */
1195 	m_fs->e2fs_ncg = howmany(u32, fs->e2fs_bpg);
1196 	if (m_fs->e2fs_ncg == 0) {
1197 		printf("ext2fs: invalid number of cylinder groups\n");
1198 		return EINVAL;
1199 	}
1200 
1201 	m_fs->e2fs_fsbtodb = fs->e2fs_log_bsize + LOG_MINBSIZE - DEV_BSHIFT;
1202 	m_fs->e2fs_bsize = MINBSIZE << fs->e2fs_log_bsize;
1203 	m_fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs_log_bsize;
1204 	m_fs->e2fs_qbmask = m_fs->e2fs_bsize - 1;
1205 	m_fs->e2fs_bmask = ~m_fs->e2fs_qbmask;
1206 
1207 	if ((u32 = m_fs->e2fs_bsize / sizeof(struct ext2_gd)) == 0) {
1208 		/* Unlikely to happen */
1209 		printf("ext2fs: invalid block size\n");
1210 		return EINVAL;
1211 	}
1212 	m_fs->e2fs_ngdb = howmany(m_fs->e2fs_ncg, u32);
1213 	if (m_fs->e2fs_ngdb == 0) {
1214 		printf("ext2fs: invalid number of group descriptor blocks\n");
1215 		return EINVAL;
1216 	}
1217 
1218 	if (m_fs->e2fs_bsize < EXT2_DINODE_SIZE(m_fs)) {
1219 		printf("ext2fs: invalid inode size\n");
1220 		return EINVAL;
1221 	}
1222 	m_fs->e2fs_ipb = m_fs->e2fs_bsize / EXT2_DINODE_SIZE(m_fs);
1223 
1224 	m_fs->e2fs_itpg = fs->e2fs_ipg / m_fs->e2fs_ipb;
1225 
1226 	/*
1227 	 * Revision-specific checks
1228 	 */
1229 	if (fs->e2fs_rev > E2FS_REV0) {
1230 		char buf[256];
1231 		if (fs->e2fs_first_ino != EXT2_FIRSTINO) {
1232 			printf("ext2fs: unsupported first inode position\n");
1233 			return EINVAL;
1234 		}
1235 		u32 = fs->e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP;
1236 		if (u32) {
1237 			snprintb(buf, sizeof(buf), EXT2F_INCOMPAT_BITS, u32);
1238 			printf("ext2fs: unsupported incompat features: %s\n", buf);
1239 #ifndef EXT2_IGNORE_INCOMPAT_FEATURES
1240 			return EINVAL;
1241 #endif
1242 		}
1243 		u32 = fs->e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP;
1244 		if (!ronly && u32) {
1245 			snprintb(buf, sizeof(buf), EXT2F_ROCOMPAT_BITS, u32);
1246 			printf("ext2fs: unsupported ro-incompat features: %s\n",
1247 			    buf);
1248 #ifndef EXT2_IGNORE_ROCOMPAT_FEATURES
1249 			return EROFS;
1250 #endif
1251 		}
1252 		if (fs->e2fs_inode_size == 0 || !powerof2(fs->e2fs_inode_size) || fs->e2fs_inode_size > m_fs->e2fs_bsize) {
1253 			printf("ext2fs: bad inode size\n");
1254 			return EINVAL;
1255 		}
1256 	}
1257 
1258 	return 0;
1259 }
1260