xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_vfsops.c (revision 9616dacfef448e70e3fbbd865bddf60d54b656c5)
1 /*	$NetBSD: ext2fs_vfsops.c,v 1.204 2016/08/25 07:18:35 christos 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 1.204 2016/08/25 07:18:35 christos 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 static void
243 ext2fs_sb_setmountinfo(struct m_ext2fs *fs, struct mount *mp)
244 {
245 	(void)strlcpy(fs->e2fs_fsmnt, mp->mnt_stat.f_mntonname,
246             sizeof(fs->e2fs_fsmnt));
247 	if (fs->e2fs_ronly == 0 && fs->e2fs.e2fs_rev > E2FS_REV0) {
248 		(void)strlcpy(fs->e2fs.e2fs_fsmnt, mp->mnt_stat.f_mntonname,
249 		    sizeof(fs->e2fs.e2fs_fsmnt));
250 
251 		fs->e2fs.e2fs_mtime = time_second;
252 		fs->e2fs.e2fs_mnt_count++;
253 
254 		fs->e2fs_fmod = 1;
255 	}
256 }
257 
258 /*
259  * Called by main() when ext2fs is going to be mounted as root.
260  *
261  * Name is updated by mount(8) after booting.
262  */
263 
264 int
265 ext2fs_mountroot(void)
266 {
267 	extern struct vnode *rootvp;
268 	struct m_ext2fs *fs;
269 	struct mount *mp;
270 	struct ufsmount *ump;
271 	int error;
272 
273 	if (device_class(root_device) != DV_DISK)
274 		return ENODEV;
275 
276 	if ((error = vfs_rootmountalloc(MOUNT_EXT2FS, "root_device", &mp))) {
277 		vrele(rootvp);
278 		return error;
279 	}
280 
281 	if ((error = ext2fs_mountfs(rootvp, mp)) != 0) {
282 		vfs_unbusy(mp, false, NULL);
283 		vfs_destroy(mp);
284 		return error;
285 	}
286 	mountlist_append(mp);
287 	ump = VFSTOUFS(mp);
288 	fs = ump->um_e2fs;
289 	ext2fs_sb_setmountinfo(fs, mp);
290 	(void)ext2fs_statvfs(mp, &mp->mnt_stat);
291 	vfs_unbusy(mp, false, NULL);
292 	setrootfstime((time_t)fs->e2fs.e2fs_wtime);
293 	return 0;
294 }
295 
296 /*
297  * VFS Operations.
298  *
299  * mount system call
300  */
301 int
302 ext2fs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
303 {
304 	struct lwp *l = curlwp;
305 	struct vnode *devvp;
306 	struct ufs_args *args = data;
307 	struct ufsmount *ump = NULL;
308 	struct m_ext2fs *fs;
309 	int error = 0, flags, update;
310 	mode_t accessmode;
311 
312 	if (args == NULL)
313 		return EINVAL;
314 	if (*data_len < sizeof *args)
315 		return EINVAL;
316 
317 	if (mp->mnt_flag & MNT_GETARGS) {
318 		ump = VFSTOUFS(mp);
319 		if (ump == NULL)
320 			return EIO;
321 		memset(args, 0, sizeof *args);
322 		args->fspec = NULL;
323 		*data_len = sizeof *args;
324 		return 0;
325 	}
326 
327 	update = mp->mnt_flag & MNT_UPDATE;
328 
329 	/* Check arguments */
330 	if (args->fspec != NULL) {
331 		/*
332 		 * Look up the name and verify that it's sane.
333 		 */
334 		error = namei_simple_user(args->fspec,
335 					NSM_FOLLOW_NOEMULROOT, &devvp);
336 		if (error != 0)
337 			return error;
338 
339 		if (!update) {
340 			/*
341 			 * Be sure this is a valid block device
342 			 */
343 			if (devvp->v_type != VBLK)
344 				error = ENOTBLK;
345 			else if (bdevsw_lookup(devvp->v_rdev) == NULL)
346 				error = ENXIO;
347 		} else {
348 		        /*
349 			 * Be sure we're still naming the same device
350 			 * used for our initial mount
351 			 */
352 			ump = VFSTOUFS(mp);
353 			if (devvp != ump->um_devvp) {
354 				if (devvp->v_rdev != ump->um_devvp->v_rdev)
355 					error = EINVAL;
356 				else {
357 					vrele(devvp);
358 					devvp = ump->um_devvp;
359 					vref(devvp);
360 				}
361 			}
362 		}
363 	} else {
364 		if (!update) {
365 			/* New mounts must have a filename for the device */
366 			return EINVAL;
367 		} else {
368 			ump = VFSTOUFS(mp);
369 			devvp = ump->um_devvp;
370 			vref(devvp);
371 		}
372 	}
373 
374 	/*
375 	 * If mount by non-root, then verify that user has necessary
376 	 * permissions on the device.
377 	 *
378 	 * Permission to update a mount is checked higher, so here we presume
379 	 * updating the mount is okay (for example, as far as securelevel goes)
380 	 * which leaves us with the normal check.
381 	 */
382 	if (error == 0) {
383 		accessmode = VREAD;
384 		if (update ?
385 		    (mp->mnt_iflag & IMNT_WANTRDWR) != 0 :
386 		    (mp->mnt_flag & MNT_RDONLY) == 0)
387 			accessmode |= VWRITE;
388 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
389 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
390 		    KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp,
391 		    KAUTH_ARG(accessmode));
392 		VOP_UNLOCK(devvp);
393 	}
394 
395 	if (error) {
396 		vrele(devvp);
397 		return error;
398 	}
399 
400 	if (!update) {
401 		int xflags;
402 
403 		if (mp->mnt_flag & MNT_RDONLY)
404 			xflags = FREAD;
405 		else
406 			xflags = FREAD|FWRITE;
407 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
408 		error = VOP_OPEN(devvp, xflags, FSCRED);
409 		VOP_UNLOCK(devvp);
410 		if (error)
411 			goto fail;
412 		error = ext2fs_mountfs(devvp, mp);
413 		if (error) {
414 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
415 			(void)VOP_CLOSE(devvp, xflags, NOCRED);
416 			VOP_UNLOCK(devvp);
417 			goto fail;
418 		}
419 
420 		ump = VFSTOUFS(mp);
421 		fs = ump->um_e2fs;
422 	} else {
423 		/*
424 		 * Update the mount.
425 		 */
426 
427 		/*
428 		 * The initial mount got a reference on this
429 		 * device, so drop the one obtained via
430 		 * namei(), above.
431 		 */
432 		vrele(devvp);
433 
434 		ump = VFSTOUFS(mp);
435 		fs = ump->um_e2fs;
436 		if (fs->e2fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
437 			/*
438 			 * Changing from r/w to r/o
439 			 */
440 			flags = WRITECLOSE;
441 			if (mp->mnt_flag & MNT_FORCE)
442 				flags |= FORCECLOSE;
443 			error = ext2fs_flushfiles(mp, flags);
444 			if (error == 0 &&
445 			    ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
446 			    (fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
447 				fs->e2fs.e2fs_state = E2FS_ISCLEAN;
448 				(void) ext2fs_sbupdate(ump, MNT_WAIT);
449 			}
450 			if (error)
451 				return error;
452 			fs->e2fs_ronly = 1;
453 		}
454 
455 		if (mp->mnt_flag & MNT_RELOAD) {
456 			error = ext2fs_reload(mp, l->l_cred, l);
457 			if (error)
458 				return error;
459 		}
460 
461 		if (fs->e2fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) {
462 			/*
463 			 * Changing from read-only to read/write
464 			 */
465 			fs->e2fs_ronly = 0;
466 			if (fs->e2fs.e2fs_state == E2FS_ISCLEAN)
467 				fs->e2fs.e2fs_state = 0;
468 			else
469 				fs->e2fs.e2fs_state = E2FS_ERRORS;
470 			fs->e2fs_fmod = 1;
471 		}
472 		if (args->fspec == NULL)
473 			return 0;
474 	}
475 
476 	error = set_statvfs_info(path, UIO_USERSPACE, args->fspec,
477 	    UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
478 	if (error == 0)
479 		ext2fs_sb_setmountinfo(fs, mp);
480 
481 	if (fs->e2fs_fmod != 0) {	/* XXX */
482 		fs->e2fs_fmod = 0;
483 		if (fs->e2fs.e2fs_state == 0)
484 			fs->e2fs.e2fs_wtime = time_second;
485 		else
486 			printf("%s: file system not clean; please fsck(8)\n",
487 				mp->mnt_stat.f_mntfromname);
488 		(void) ext2fs_cgupdate(ump, MNT_WAIT);
489 	}
490 	return error;
491 
492 fail:
493 	vrele(devvp);
494 	return error;
495 }
496 
497 /*
498  * Sanity check the disk vnode content, and copy it over to inode structure.
499  */
500 static int
501 ext2fs_loadvnode_content(struct m_ext2fs *fs, ino_t ino, struct buf *bp, struct inode *ip)
502 {
503 	struct ext2fs_dinode *din;
504 	int error = 0;
505 
506 	din = (struct ext2fs_dinode *)((char *)bp->b_data + (ino_to_fsbo(fs, ino) * EXT2_DINODE_SIZE(fs)));
507 
508 	/* sanity checks - inode data NOT byteswapped at this point */
509 	if (EXT2_DINODE_FITS(din, e2di_extra_isize, EXT2_DINODE_SIZE(fs))
510 	    && (EXT2_DINODE_SIZE(fs) - EXT2_REV0_DINODE_SIZE) < fs2h16(din->e2di_extra_isize))
511 	{
512 		printf("ext2fs: inode %"PRIu64" bad extra_isize %u",
513 			ino, din->e2di_extra_isize);
514 		error = EINVAL;
515 		goto bad;
516 	}
517 
518 	/* everything allright, proceed with copy */
519 	if (ip->i_din.e2fs_din == NULL)
520 		ip->i_din.e2fs_din = kmem_alloc(EXT2_DINODE_SIZE(fs), KM_SLEEP);
521 
522 	e2fs_iload(din, ip->i_din.e2fs_din, EXT2_DINODE_SIZE(fs));
523 
524 	ext2fs_set_inode_guid(ip);
525 
526     bad:
527 	return error;
528 }
529 
530 /*
531  * Reload all incore data for a filesystem (used after running fsck on
532  * the root filesystem and finding things to fix). The filesystem must
533  * be mounted read-only.
534  *
535  * Things to do to update the mount:
536  *	1) invalidate all cached meta-data.
537  *	2) re-read superblock from disk.
538  *	3) re-read summary information from disk.
539  *	4) invalidate all inactive vnodes.
540  *	5) invalidate all cached file data.
541  *	6) re-read inode data for all active vnodes.
542  */
543 int
544 ext2fs_reload(struct mount *mp, kauth_cred_t cred, struct lwp *l)
545 {
546 	struct vnode *vp, *devvp;
547 	struct inode *ip;
548 	struct buf *bp;
549 	struct m_ext2fs *fs;
550 	struct ext2fs *newfs;
551 	int i, error;
552 	struct ufsmount *ump;
553 	struct vnode_iterator *marker;
554 
555 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
556 		return EINVAL;
557 
558 	ump = VFSTOUFS(mp);
559 	/*
560 	 * Step 1: invalidate all cached meta-data.
561 	 */
562 	devvp = ump->um_devvp;
563 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
564 	error = vinvalbuf(devvp, 0, cred, l, 0, 0);
565 	VOP_UNLOCK(devvp);
566 	if (error)
567 		panic("ext2fs_reload: dirty1");
568 
569 	fs = ump->um_e2fs;
570 	/*
571 	 * Step 2: re-read superblock from disk. Copy in new superblock, and compute
572 	 * in-memory values.
573 	 */
574 	error = bread(devvp, SBLOCK, SBSIZE, 0, &bp);
575 	if (error)
576 		return error;
577 	newfs = (struct ext2fs *)bp->b_data;
578 	e2fs_sbload(newfs, &fs->e2fs);
579 
580 	brelse(bp, 0);
581 
582 	error = ext2fs_sbfill(fs, (mp->mnt_flag & MNT_RDONLY) != 0);
583 	if (error)
584 		return error;
585 
586 	/*
587 	 * Step 3: re-read summary information from disk.
588 	 */
589 	for (i = 0; i < fs->e2fs_ngdb; i++) {
590 		error = bread(devvp ,
591 		    EXT2_FSBTODB(fs, fs->e2fs.e2fs_first_dblock +
592 		    1 /* superblock */ + i),
593 		    fs->e2fs_bsize, 0, &bp);
594 		if (error) {
595 			return error;
596 		}
597 		e2fs_cgload((struct ext2_gd *)bp->b_data,
598 		    &fs->e2fs_gd[i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
599 		    fs->e2fs_bsize);
600 		brelse(bp, 0);
601 	}
602 
603 	vfs_vnode_iterator_init(mp, &marker);
604 	while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL))) {
605 		/*
606 		 * Step 4: invalidate all inactive vnodes.
607 		 */
608 		if (vrecycle(vp))
609 			continue;
610 		/*
611 		 * Step 5: invalidate all cached file data.
612 		 */
613 		if (vn_lock(vp, LK_EXCLUSIVE)) {
614 			vrele(vp);
615 			continue;
616 		}
617 		if (vinvalbuf(vp, 0, cred, l, 0, 0))
618 			panic("ext2fs_reload: dirty2");
619 		/*
620 		 * Step 6: re-read inode data for all active vnodes.
621 		 */
622 		ip = VTOI(vp);
623 		error = bread(devvp, EXT2_FSBTODB(fs, ino_to_fsba(fs, ip->i_number)),
624 		    (int)fs->e2fs_bsize, 0, &bp);
625 		if (error) {
626 			vput(vp);
627 			break;
628 		}
629 		error = ext2fs_loadvnode_content(fs, ip->i_number, bp, ip);
630 		brelse(bp, 0);
631 		if (error) {
632 			vput(vp);
633 			break;
634 		}
635 
636 		vput(vp);
637 	}
638 	vfs_vnode_iterator_destroy(marker);
639 	return error;
640 }
641 
642 /*
643  * Common code for mount and mountroot
644  */
645 int
646 ext2fs_mountfs(struct vnode *devvp, struct mount *mp)
647 {
648 	struct lwp *l = curlwp;
649 	struct ufsmount *ump;
650 	struct buf *bp;
651 	struct ext2fs *fs;
652 	struct m_ext2fs *m_fs;
653 	dev_t dev;
654 	int error, i, ronly;
655 	kauth_cred_t cred;
656 
657 	dev = devvp->v_rdev;
658 	cred = l->l_cred;
659 
660 	/* Flush out any old buffers remaining from a previous use. */
661 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
662 	error = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0);
663 	VOP_UNLOCK(devvp);
664 	if (error)
665 		return error;
666 
667 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
668 
669 	bp = NULL;
670 	ump = NULL;
671 
672 	/* Read the superblock from disk, and swap it directly. */
673 	error = bread(devvp, SBLOCK, SBSIZE, 0, &bp);
674 	if (error)
675 		goto out;
676 	fs = (struct ext2fs *)bp->b_data;
677 	m_fs = kmem_zalloc(sizeof(struct m_ext2fs), KM_SLEEP);
678 	e2fs_sbload(fs, &m_fs->e2fs);
679 
680 	brelse(bp, 0);
681 	bp = NULL;
682 
683 	/* Once swapped, validate and fill in the superblock. */
684 	error = ext2fs_sbfill(m_fs, ronly);
685 	if (error) {
686 		kmem_free(m_fs, sizeof(struct m_ext2fs));
687 		goto out;
688 	}
689 	m_fs->e2fs_ronly = ronly;
690 
691 	ump = kmem_zalloc(sizeof(*ump), KM_SLEEP);
692 	ump->um_fstype = UFS1;
693 	ump->um_ops = &ext2fs_ufsops;
694 	ump->um_e2fs = m_fs;
695 
696 	if (ronly == 0) {
697 		if (m_fs->e2fs.e2fs_state == E2FS_ISCLEAN)
698 			m_fs->e2fs.e2fs_state = 0;
699 		else
700 			m_fs->e2fs.e2fs_state = E2FS_ERRORS;
701 		m_fs->e2fs_fmod = 1;
702 	}
703 
704 	/* XXX: should be added in ext2fs_sbfill()? */
705 	m_fs->e2fs_gd = kmem_alloc(m_fs->e2fs_ngdb * m_fs->e2fs_bsize, KM_SLEEP);
706 	for (i = 0; i < m_fs->e2fs_ngdb; i++) {
707 		error = bread(devvp,
708 		    EXT2_FSBTODB(m_fs, m_fs->e2fs.e2fs_first_dblock +
709 		    1 /* superblock */ + i),
710 		    m_fs->e2fs_bsize, 0, &bp);
711 		if (error) {
712 			kmem_free(m_fs->e2fs_gd,
713 			    m_fs->e2fs_ngdb * m_fs->e2fs_bsize);
714 			goto out;
715 		}
716 		e2fs_cgload((struct ext2_gd *)bp->b_data,
717 		    &m_fs->e2fs_gd[
718 			i * m_fs->e2fs_bsize / sizeof(struct ext2_gd)],
719 		    m_fs->e2fs_bsize);
720 		brelse(bp, 0);
721 		bp = NULL;
722 	}
723 
724 	error = ext2fs_cg_verify_and_initialize(devvp, m_fs, ronly);
725 	if (error) {
726 		kmem_free(m_fs->e2fs_gd, m_fs->e2fs_ngdb * m_fs->e2fs_bsize);
727 		goto out;
728 	}
729 
730 	mp->mnt_data = ump;
731 	mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
732 	mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_EXT2FS);
733 	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
734 	mp->mnt_stat.f_namemax = EXT2FS_MAXNAMLEN;
735 	mp->mnt_flag |= MNT_LOCAL;
736 	mp->mnt_dev_bshift = DEV_BSHIFT;	/* XXX */
737 	mp->mnt_fs_bshift = m_fs->e2fs_bshift;
738 	mp->mnt_iflag |= IMNT_DTYPE;
739 	ump->um_flags = 0;
740 	ump->um_mountp = mp;
741 	ump->um_dev = dev;
742 	ump->um_devvp = devvp;
743 	ump->um_nindir = EXT2_NINDIR(m_fs);
744 	ump->um_lognindir = ffs(EXT2_NINDIR(m_fs)) - 1;
745 	ump->um_bptrtodb = m_fs->e2fs_fsbtodb;
746 	ump->um_seqinc = 1; /* no frags */
747 	ump->um_maxsymlinklen = EXT2_MAXSYMLINKLEN;
748 	ump->um_dirblksiz = m_fs->e2fs_bsize;
749 	ump->um_maxfilesize = ((uint64_t)0x80000000 * m_fs->e2fs_bsize - 1);
750 	spec_node_setmountedfs(devvp, mp);
751 	return 0;
752 
753 out:
754 	if (bp != NULL)
755 		brelse(bp, 0);
756 	if (ump) {
757 		kmem_free(ump->um_e2fs, sizeof(struct m_ext2fs));
758 		kmem_free(ump, sizeof(*ump));
759 		mp->mnt_data = NULL;
760 	}
761 	return error;
762 }
763 
764 /*
765  * unmount system call
766  */
767 int
768 ext2fs_unmount(struct mount *mp, int mntflags)
769 {
770 	struct ufsmount *ump;
771 	struct m_ext2fs *fs;
772 	int error, flags;
773 
774 	flags = 0;
775 	if (mntflags & MNT_FORCE)
776 		flags |= FORCECLOSE;
777 	if ((error = ext2fs_flushfiles(mp, flags)) != 0)
778 		return error;
779 	ump = VFSTOUFS(mp);
780 	fs = ump->um_e2fs;
781 	if (fs->e2fs_ronly == 0 &&
782 		ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
783 		(fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
784 		fs->e2fs.e2fs_state = E2FS_ISCLEAN;
785 		(void) ext2fs_sbupdate(ump, MNT_WAIT);
786 	}
787 	if (ump->um_devvp->v_type != VBAD)
788 		spec_node_setmountedfs(ump->um_devvp, NULL);
789 	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
790 	error = VOP_CLOSE(ump->um_devvp, fs->e2fs_ronly ? FREAD : FREAD|FWRITE,
791 	    NOCRED);
792 	vput(ump->um_devvp);
793 	kmem_free(fs->e2fs_gd, fs->e2fs_ngdb * fs->e2fs_bsize);
794 	kmem_free(fs, sizeof(*fs));
795 	kmem_free(ump, sizeof(*ump));
796 	mp->mnt_data = NULL;
797 	mp->mnt_flag &= ~MNT_LOCAL;
798 	return error;
799 }
800 
801 /*
802  * Flush out all the files in a filesystem.
803  */
804 int
805 ext2fs_flushfiles(struct mount *mp, int flags)
806 {
807 	extern int doforce;
808 	int error;
809 
810 	if (!doforce)
811 		flags &= ~FORCECLOSE;
812 	error = vflush(mp, NULLVP, flags);
813 	return error;
814 }
815 
816 /*
817  * Get file system statistics.
818  */
819 int
820 ext2fs_statvfs(struct mount *mp, struct statvfs *sbp)
821 {
822 	struct ufsmount *ump;
823 	struct m_ext2fs *fs;
824 	uint32_t overhead, overhead_per_group, ngdb;
825 	int i, ngroups;
826 
827 	ump = VFSTOUFS(mp);
828 	fs = ump->um_e2fs;
829 	if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
830 		panic("ext2fs_statvfs");
831 
832 	/*
833 	 * Compute the overhead (FS structures)
834 	 */
835 	overhead_per_group =
836 	    1 /* block bitmap */ +
837 	    1 /* inode bitmap */ +
838 	    fs->e2fs_itpg;
839 	overhead = fs->e2fs.e2fs_first_dblock +
840 	    fs->e2fs_ncg * overhead_per_group;
841 	if (EXT2F_HAS_COMPAT_FEATURE(fs, EXT2F_COMPAT_SPARSESUPER2)) {
842 		/*
843 		 * Superblock and group descriptions is in group zero,
844 		 * then optionally 0, 1 or 2 extra copies.
845 		 */
846 		ngroups = 1
847 			+ (fs->e2fs.e4fs_backup_bgs[0] ? 1 : 0)
848 			+ (fs->e2fs.e4fs_backup_bgs[1] ? 1 : 0);
849 	} else if (EXT2F_HAS_ROCOMPAT_FEATURE(fs, EXT2F_ROCOMPAT_SPARSESUPER)) {
850 		for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
851 			if (cg_has_sb(i))
852 				ngroups++;
853 		}
854 	} else {
855 		ngroups = fs->e2fs_ncg;
856 	}
857 	ngdb = fs->e2fs_ngdb;
858 	if (EXT2F_HAS_COMPAT_FEATURE(fs, EXT2F_COMPAT_RESIZE))
859 		ngdb += fs->e2fs.e2fs_reserved_ngdb;
860 	overhead += ngroups * (1 /* superblock */ + ngdb);
861 
862 	sbp->f_bsize = fs->e2fs_bsize;
863 	sbp->f_frsize = MINBSIZE << fs->e2fs.e2fs_fsize;
864 	sbp->f_iosize = fs->e2fs_bsize;
865 	sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
866 	sbp->f_bfree = fs->e2fs.e2fs_fbcount;
867 	sbp->f_bresvd = fs->e2fs.e2fs_rbcount;
868 	if (sbp->f_bfree > sbp->f_bresvd)
869 		sbp->f_bavail = sbp->f_bfree - sbp->f_bresvd;
870 	else
871 		sbp->f_bavail = 0;
872 	sbp->f_files =  fs->e2fs.e2fs_icount;
873 	sbp->f_ffree = fs->e2fs.e2fs_ficount;
874 	sbp->f_favail = fs->e2fs.e2fs_ficount;
875 	sbp->f_fresvd = 0;
876 	copy_statvfs_info(sbp, mp);
877 	return 0;
878 }
879 
880 static bool
881 ext2fs_sync_selector(void *cl, struct vnode *vp)
882 {
883 	struct inode *ip;
884 
885 	ip = VTOI(vp);
886 	/*
887 	 * Skip the vnode/inode if inaccessible.
888 	 */
889 	if (ip == NULL || vp->v_type == VNON)
890 		return false;
891 
892 	if (((ip->i_flag &
893 	      (IN_CHANGE | IN_UPDATE | IN_MODIFIED)) == 0 &&
894 	     LIST_EMPTY(&vp->v_dirtyblkhd) &&
895 	     UVM_OBJ_IS_CLEAN(&vp->v_uobj)))
896 		return false;
897 	return true;
898 }
899 
900 /*
901  * Go through the disk queues to initiate sandbagged IO;
902  * go through the inodes to write those that have been modified;
903  * initiate the writing of the super block if it has been modified.
904  *
905  * Note: we are always called with the filesystem marked `MPBUSY'.
906  */
907 int
908 ext2fs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
909 {
910 	struct vnode *vp;
911 	struct ufsmount *ump = VFSTOUFS(mp);
912 	struct m_ext2fs *fs;
913 	struct vnode_iterator *marker;
914 	int error, allerror = 0;
915 
916 	fs = ump->um_e2fs;
917 	if (fs->e2fs_fmod != 0 && fs->e2fs_ronly != 0) {	/* XXX */
918 		printf("fs = %s\n", fs->e2fs_fsmnt);
919 		panic("update: rofs mod");
920 	}
921 
922 	/*
923 	 * Write back each (modified) inode.
924 	 */
925 	vfs_vnode_iterator_init(mp, &marker);
926 	while ((vp = vfs_vnode_iterator_next(marker, ext2fs_sync_selector,
927 	    NULL)))
928 	{
929 		error = vn_lock(vp, LK_EXCLUSIVE);
930 		if (error) {
931 			vrele(vp);
932 			continue;
933 		}
934 		if (vp->v_type == VREG && waitfor == MNT_LAZY)
935 			error = ext2fs_update(vp, NULL, NULL, 0);
936 		else
937 			error = VOP_FSYNC(vp, cred,
938 			    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0);
939 		if (error)
940 			allerror = error;
941 		vput(vp);
942 	}
943 	vfs_vnode_iterator_destroy(marker);
944 	/*
945 	 * Force stale file system control information to be flushed.
946 	 */
947 	if (waitfor != MNT_LAZY) {
948 		vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
949 		if ((error = VOP_FSYNC(ump->um_devvp, cred,
950 		    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
951 			allerror = error;
952 		VOP_UNLOCK(ump->um_devvp);
953 	}
954 	/*
955 	 * Write back modified superblock.
956 	 */
957 	if (fs->e2fs_fmod != 0) {
958 		fs->e2fs_fmod = 0;
959 		fs->e2fs.e2fs_wtime = time_second;
960 		if ((error = ext2fs_cgupdate(ump, waitfor)))
961 			allerror = error;
962 	}
963 	return allerror;
964 }
965 
966 /*
967  * Read an inode from disk and initialize this vnode / inode pair.
968  * Caller assures no other thread will try to load this inode.
969  */
970 int
971 ext2fs_loadvnode(struct mount *mp, struct vnode *vp,
972     const void *key, size_t key_len, const void **new_key)
973 {
974 	ino_t ino;
975 	struct m_ext2fs *fs;
976 	struct inode *ip;
977 	struct ufsmount *ump;
978 	struct buf *bp;
979 	dev_t dev;
980 	int error;
981 
982 	KASSERT(key_len == sizeof(ino));
983 	memcpy(&ino, key, key_len);
984 	ump = VFSTOUFS(mp);
985 	dev = ump->um_dev;
986 	fs = ump->um_e2fs;
987 
988 	/* Read in the disk contents for the inode, copy into the inode. */
989 	error = bread(ump->um_devvp, EXT2_FSBTODB(fs, ino_to_fsba(fs, ino)),
990 	    (int)fs->e2fs_bsize, 0, &bp);
991 	if (error)
992 		return error;
993 
994 	/* Allocate and initialize inode. */
995 	ip = pool_get(&ext2fs_inode_pool, PR_WAITOK);
996 	memset(ip, 0, sizeof(struct inode));
997 	vp->v_tag = VT_EXT2FS;
998 	vp->v_op = ext2fs_vnodeop_p;
999 	vp->v_vflag |= VV_LOCKSWORK;
1000 	vp->v_data = ip;
1001 	ip->i_vnode = vp;
1002 	ip->i_ump = ump;
1003 	ip->i_e2fs = fs;
1004 	ip->i_dev = dev;
1005 	ip->i_number = ino;
1006 	ip->i_e2fs_last_lblk = 0;
1007 	ip->i_e2fs_last_blk = 0;
1008 
1009 	/* Initialize genfs node. */
1010 	genfs_node_init(vp, &ext2fs_genfsops);
1011 
1012 	error = ext2fs_loadvnode_content(fs, ino, bp, ip);
1013 	brelse(bp, 0);
1014 	if (error)
1015 		return error;
1016 
1017 	/* If the inode was deleted, reset all fields */
1018 	if (ip->i_e2fs_dtime != 0) {
1019 		ip->i_e2fs_mode = 0;
1020 		(void)ext2fs_setsize(ip, 0);
1021 		(void)ext2fs_setnblock(ip, 0);
1022 		memset(ip->i_e2fs_blocks, 0, sizeof(ip->i_e2fs_blocks));
1023 	}
1024 
1025 	/* Initialize the vnode from the inode. */
1026 	ext2fs_vinit(mp, ext2fs_specop_p, ext2fs_fifoop_p, &vp);
1027 
1028 	/* Finish inode initialization. */
1029 	ip->i_devvp = ump->um_devvp;
1030 	vref(ip->i_devvp);
1031 
1032 	/*
1033 	 * Set up a generation number for this inode if it does not
1034 	 * already have one. This should only happen on old filesystems.
1035 	 */
1036 
1037 	if (ip->i_e2fs_gen == 0) {
1038 		if (++ext2gennumber < (u_long)time_second)
1039 			ext2gennumber = time_second;
1040 		ip->i_e2fs_gen = ext2gennumber;
1041 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
1042 			ip->i_flag |= IN_MODIFIED;
1043 	}
1044 	uvm_vnp_setsize(vp, ext2fs_size(ip));
1045 	*new_key = &ip->i_number;
1046 	return 0;
1047 }
1048 
1049 /*
1050  * File handle to vnode
1051  *
1052  * Have to be really careful about stale file handles:
1053  * - check that the inode number is valid
1054  * - call ext2fs_vget() to get the locked inode
1055  * - check for an unallocated inode (i_mode == 0)
1056  */
1057 int
1058 ext2fs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
1059 {
1060 	struct inode *ip;
1061 	struct vnode *nvp;
1062 	int error;
1063 	struct ufid ufh;
1064 	struct m_ext2fs *fs;
1065 
1066 	if (fhp->fid_len != sizeof(struct ufid))
1067 		return EINVAL;
1068 
1069 	memcpy(&ufh, fhp, sizeof(struct ufid));
1070 	fs = VFSTOUFS(mp)->um_e2fs;
1071 	if ((ufh.ufid_ino < EXT2_FIRSTINO && ufh.ufid_ino != EXT2_ROOTINO) ||
1072 		ufh.ufid_ino >= fs->e2fs_ncg * fs->e2fs.e2fs_ipg)
1073 		return ESTALE;
1074 
1075 	if ((error = VFS_VGET(mp, ufh.ufid_ino, &nvp)) != 0) {
1076 		*vpp = NULLVP;
1077 		return error;
1078 	}
1079 	ip = VTOI(nvp);
1080 	if (ip->i_e2fs_mode == 0 || ip->i_e2fs_dtime != 0 ||
1081 		ip->i_e2fs_gen != ufh.ufid_gen) {
1082 		vput(nvp);
1083 		*vpp = NULLVP;
1084 		return ESTALE;
1085 	}
1086 	*vpp = nvp;
1087 	return 0;
1088 }
1089 
1090 /*
1091  * Vnode pointer to File handle
1092  */
1093 /* ARGSUSED */
1094 int
1095 ext2fs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
1096 {
1097 	struct inode *ip;
1098 	struct ufid ufh;
1099 
1100 	if (*fh_size < sizeof(struct ufid)) {
1101 		*fh_size = sizeof(struct ufid);
1102 		return E2BIG;
1103 	}
1104 	*fh_size = sizeof(struct ufid);
1105 
1106 	ip = VTOI(vp);
1107 	memset(&ufh, 0, sizeof(ufh));
1108 	ufh.ufid_len = sizeof(struct ufid);
1109 	ufh.ufid_ino = ip->i_number;
1110 	ufh.ufid_gen = ip->i_e2fs_gen;
1111 	memcpy(fhp, &ufh, sizeof(ufh));
1112 	return 0;
1113 }
1114 
1115 /*
1116  * Write a superblock and associated information back to disk.
1117  */
1118 int
1119 ext2fs_sbupdate(struct ufsmount *mp, int waitfor)
1120 {
1121 	struct m_ext2fs *fs = mp->um_e2fs;
1122 	struct buf *bp;
1123 	int error = 0;
1124 
1125 	bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, 0);
1126 	e2fs_sbsave(&fs->e2fs, (struct ext2fs*)bp->b_data);
1127 	if (waitfor == MNT_WAIT)
1128 		error = bwrite(bp);
1129 	else
1130 		bawrite(bp);
1131 	return error;
1132 }
1133 
1134 int
1135 ext2fs_cgupdate(struct ufsmount *mp, int waitfor)
1136 {
1137 	struct m_ext2fs *fs = mp->um_e2fs;
1138 	struct buf *bp;
1139 	int i, error = 0, allerror = 0;
1140 
1141 	allerror = ext2fs_sbupdate(mp, waitfor);
1142 	for (i = 0; i < fs->e2fs_ngdb; i++) {
1143 		bp = getblk(mp->um_devvp, EXT2_FSBTODB(fs,
1144 		    fs->e2fs.e2fs_first_dblock +
1145 		    1 /* superblock */ + i), fs->e2fs_bsize, 0, 0);
1146 		e2fs_cgsave(&fs->e2fs_gd[
1147 		    i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
1148 		    (struct ext2_gd *)bp->b_data, fs->e2fs_bsize);
1149 		if (waitfor == MNT_WAIT)
1150 			error = bwrite(bp);
1151 		else
1152 			bawrite(bp);
1153 	}
1154 
1155 	if (!allerror && error)
1156 		allerror = error;
1157 	return allerror;
1158 }
1159 
1160 /*
1161  * Fill in the m_fs structure, and validate the fields of the superblock.
1162  * NOTE: here, the superblock is already swapped.
1163  */
1164 static int
1165 ext2fs_sbfill(struct m_ext2fs *m_fs, int ronly)
1166 {
1167 	uint32_t u32;
1168 	struct ext2fs *fs = &m_fs->e2fs;
1169 
1170 	/*
1171 	 * General sanity checks
1172 	 */
1173 	if (fs->e2fs_magic != E2FS_MAGIC)
1174 		return EINVAL;
1175 	if (fs->e2fs_rev > E2FS_REV1) {
1176 		printf("ext2fs: unsupported revision number: %x\n", fs->e2fs_rev);
1177 		return EINVAL;
1178 	}
1179 	if (fs->e2fs_log_bsize > 2) {
1180 		/* block size = 1024|2048|4096 */
1181 		printf("ext2fs: bad block size: %d\n", fs->e2fs_log_bsize);
1182 		return EINVAL;
1183 	}
1184 	if (fs->e2fs_bpg == 0) {
1185 		printf("ext2fs: zero blocks per group\n");
1186 		return EINVAL;
1187 	}
1188 	if (fs->e2fs_ipg == 0) {
1189 		printf("ext2fs: zero inodes per group\n");
1190 		return EINVAL;
1191 	}
1192 
1193 	if (fs->e2fs_first_dblock >= fs->e2fs_bcount) {
1194 		printf("ext2fs: invalid first data block\n");
1195 		return EINVAL;
1196 	}
1197 	if (fs->e2fs_rbcount > fs->e2fs_bcount ||
1198 	    fs->e2fs_fbcount > fs->e2fs_bcount) {
1199 		printf("ext2fs: invalid block count\n");
1200 		return EINVAL;
1201 	}
1202 
1203 	/*
1204 	 * Compute the fields of the superblock
1205 	 */
1206 	u32 = fs->e2fs_bcount - fs->e2fs_first_dblock; /* > 0 */
1207 	m_fs->e2fs_ncg = howmany(u32, fs->e2fs_bpg);
1208 	if (m_fs->e2fs_ncg == 0) {
1209 		printf("ext2fs: invalid number of cylinder groups\n");
1210 		return EINVAL;
1211 	}
1212 
1213 	m_fs->e2fs_fsbtodb = fs->e2fs_log_bsize + LOG_MINBSIZE - DEV_BSHIFT;
1214 	m_fs->e2fs_bsize = MINBSIZE << fs->e2fs_log_bsize;
1215 	m_fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs_log_bsize;
1216 	m_fs->e2fs_qbmask = m_fs->e2fs_bsize - 1;
1217 	m_fs->e2fs_bmask = ~m_fs->e2fs_qbmask;
1218 
1219 	if ((u32 = m_fs->e2fs_bsize / sizeof(struct ext2_gd)) == 0) {
1220 		/* Unlikely to happen */
1221 		printf("ext2fs: invalid block size\n");
1222 		return EINVAL;
1223 	}
1224 	m_fs->e2fs_ngdb = howmany(m_fs->e2fs_ncg, u32);
1225 	if (m_fs->e2fs_ngdb == 0) {
1226 		printf("ext2fs: invalid number of group descriptor blocks\n");
1227 		return EINVAL;
1228 	}
1229 
1230 	if (m_fs->e2fs_bsize < EXT2_DINODE_SIZE(m_fs)) {
1231 		printf("ext2fs: invalid inode size\n");
1232 		return EINVAL;
1233 	}
1234 	m_fs->e2fs_ipb = m_fs->e2fs_bsize / EXT2_DINODE_SIZE(m_fs);
1235 
1236 	m_fs->e2fs_itpg = fs->e2fs_ipg / m_fs->e2fs_ipb;
1237 
1238 	/*
1239 	 * Revision-specific checks
1240 	 */
1241 	if (fs->e2fs_rev > E2FS_REV0) {
1242 		char buf[256];
1243 		if (fs->e2fs_first_ino != EXT2_FIRSTINO) {
1244 			printf("ext2fs: unsupported first inode position\n");
1245 			return EINVAL;
1246 		}
1247 		u32 = fs->e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP;
1248 		if (u32) {
1249 			snprintb(buf, sizeof(buf), EXT2F_INCOMPAT_BITS, u32);
1250 			printf("ext2fs: unsupported incompat features: %s\n", buf);
1251 #ifndef EXT2_IGNORE_INCOMPAT_FEATURES
1252 			return EINVAL;
1253 #endif
1254 		}
1255 		u32 = fs->e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP;
1256 		if (!ronly && u32) {
1257 			snprintb(buf, sizeof(buf), EXT2F_ROCOMPAT_BITS, u32);
1258 			printf("ext2fs: unsupported ro-incompat features: %s\n",
1259 			    buf);
1260 #ifndef EXT2_IGNORE_ROCOMPAT_FEATURES
1261 			return EROFS;
1262 #endif
1263 		}
1264 		if (fs->e2fs_inode_size == 0 || !powerof2(fs->e2fs_inode_size) || fs->e2fs_inode_size > m_fs->e2fs_bsize) {
1265 			printf("ext2fs: bad inode size\n");
1266 			return EINVAL;
1267 		}
1268 	}
1269 
1270 	return 0;
1271 }
1272