xref: /minix/sys/ufs/ext2fs/ext2fs_vfsops.c (revision 0a6a1f1d)
1 /*	$NetBSD: ext2fs_vfsops.c,v 1.193 2015/03/28 19:24:04 maxv 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 1.193 2015/03/28 19:24:04 maxv 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
ext2fs_set_inode_guid(struct inode * ip)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
ext2fs_modcmd(modcmd_t cmd,void * arg)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 struct pool ext2fs_dinode_pool;
217 
218 extern u_long ext2gennumber;
219 
220 void
ext2fs_init(void)221 ext2fs_init(void)
222 {
223 
224 	pool_init(&ext2fs_inode_pool, sizeof(struct inode), 0, 0, 0,
225 	    "ext2fsinopl", &pool_allocator_nointr, IPL_NONE);
226 	pool_init(&ext2fs_dinode_pool, sizeof(struct ext2fs_dinode), 0, 0, 0,
227 	    "ext2dinopl", &pool_allocator_nointr, IPL_NONE);
228 	ufs_init();
229 }
230 
231 void
ext2fs_reinit(void)232 ext2fs_reinit(void)
233 {
234 	ufs_reinit();
235 }
236 
237 void
ext2fs_done(void)238 ext2fs_done(void)
239 {
240 
241 	ufs_done();
242 	pool_destroy(&ext2fs_inode_pool);
243 	pool_destroy(&ext2fs_dinode_pool);
244 }
245 
246 /*
247  * Called by main() when ext2fs is going to be mounted as root.
248  *
249  * Name is updated by mount(8) after booting.
250  */
251 
252 int
ext2fs_mountroot(void)253 ext2fs_mountroot(void)
254 {
255 	extern struct vnode *rootvp;
256 	struct m_ext2fs *fs;
257 	struct mount *mp;
258 	struct ufsmount *ump;
259 	int error;
260 
261 	if (device_class(root_device) != DV_DISK)
262 		return (ENODEV);
263 
264 	if ((error = vfs_rootmountalloc(MOUNT_EXT2FS, "root_device", &mp))) {
265 		vrele(rootvp);
266 		return (error);
267 	}
268 
269 	if ((error = ext2fs_mountfs(rootvp, mp)) != 0) {
270 		vfs_unbusy(mp, false, NULL);
271 		vfs_destroy(mp);
272 		return (error);
273 	}
274 	mountlist_append(mp);
275 	ump = VFSTOUFS(mp);
276 	fs = ump->um_e2fs;
277 	memset(fs->e2fs_fsmnt, 0, sizeof(fs->e2fs_fsmnt));
278 	(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs_fsmnt,
279 	    sizeof(fs->e2fs_fsmnt) - 1, 0);
280 	if (fs->e2fs.e2fs_rev > E2FS_REV0) {
281 		memset(fs->e2fs.e2fs_fsmnt, 0, sizeof(fs->e2fs.e2fs_fsmnt));
282 		(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs.e2fs_fsmnt,
283 		    sizeof(fs->e2fs.e2fs_fsmnt) - 1, 0);
284 	}
285 	(void)ext2fs_statvfs(mp, &mp->mnt_stat);
286 	vfs_unbusy(mp, false, NULL);
287 	setrootfstime((time_t)fs->e2fs.e2fs_wtime);
288 	return (0);
289 }
290 
291 /*
292  * VFS Operations.
293  *
294  * mount system call
295  */
296 int
ext2fs_mount(struct mount * mp,const char * path,void * data,size_t * data_len)297 ext2fs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
298 {
299 	struct lwp *l = curlwp;
300 	struct vnode *devvp;
301 	struct ufs_args *args = data;
302 	struct ufsmount *ump = NULL;
303 	struct m_ext2fs *fs;
304 	size_t size;
305 	int error = 0, flags, update;
306 	mode_t accessmode;
307 
308 	if (args == NULL)
309 		return EINVAL;
310 	if (*data_len < sizeof *args)
311 		return EINVAL;
312 
313 	if (mp->mnt_flag & MNT_GETARGS) {
314 		ump = VFSTOUFS(mp);
315 		if (ump == NULL)
316 			return EIO;
317 		memset(args, 0, sizeof *args);
318 		args->fspec = NULL;
319 		*data_len = sizeof *args;
320 		return 0;
321 	}
322 
323 	update = mp->mnt_flag & MNT_UPDATE;
324 
325 	/* Check arguments */
326 	if (args->fspec != NULL) {
327 		/*
328 		 * Look up the name and verify that it's sane.
329 		 */
330 		error = namei_simple_user(args->fspec,
331 					NSM_FOLLOW_NOEMULROOT, &devvp);
332 		if (error != 0)
333 			return (error);
334 
335 		if (!update) {
336 			/*
337 			 * Be sure this is a valid block device
338 			 */
339 			if (devvp->v_type != VBLK)
340 				error = ENOTBLK;
341 			else if (bdevsw_lookup(devvp->v_rdev) == NULL)
342 				error = ENXIO;
343 		} else {
344 		        /*
345 			 * Be sure we're still naming the same device
346 			 * used for our initial mount
347 			 */
348 			ump = VFSTOUFS(mp);
349 			if (devvp != ump->um_devvp) {
350 				if (devvp->v_rdev != ump->um_devvp->v_rdev)
351 					error = EINVAL;
352 				else {
353 					vrele(devvp);
354 					devvp = ump->um_devvp;
355 					vref(devvp);
356 				}
357 			}
358 		}
359 	} else {
360 		if (!update) {
361 			/* New mounts must have a filename for the device */
362 			return (EINVAL);
363 		} else {
364 			ump = VFSTOUFS(mp);
365 			devvp = ump->um_devvp;
366 			vref(devvp);
367 		}
368 	}
369 
370 	/*
371 	 * If mount by non-root, then verify that user has necessary
372 	 * permissions on the device.
373 	 *
374 	 * Permission to update a mount is checked higher, so here we presume
375 	 * updating the mount is okay (for example, as far as securelevel goes)
376 	 * which leaves us with the normal check.
377 	 */
378 	if (error == 0) {
379 		accessmode = VREAD;
380 		if (update ?
381 		    (mp->mnt_iflag & IMNT_WANTRDWR) != 0 :
382 		    (mp->mnt_flag & MNT_RDONLY) == 0)
383 			accessmode |= VWRITE;
384 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
385 		error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
386 		    KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp,
387 		    KAUTH_ARG(accessmode));
388 		VOP_UNLOCK(devvp);
389 	}
390 
391 	if (error) {
392 		vrele(devvp);
393 		return (error);
394 	}
395 
396 	if (!update) {
397 		int xflags;
398 
399 		if (mp->mnt_flag & MNT_RDONLY)
400 			xflags = FREAD;
401 		else
402 			xflags = FREAD|FWRITE;
403 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
404 		error = VOP_OPEN(devvp, xflags, FSCRED);
405 		VOP_UNLOCK(devvp);
406 		if (error)
407 			goto fail;
408 		error = ext2fs_mountfs(devvp, mp);
409 		if (error) {
410 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
411 			(void)VOP_CLOSE(devvp, xflags, NOCRED);
412 			VOP_UNLOCK(devvp);
413 			goto fail;
414 		}
415 
416 		ump = VFSTOUFS(mp);
417 		fs = ump->um_e2fs;
418 	} else {
419 		/*
420 		 * Update the mount.
421 		 */
422 
423 		/*
424 		 * The initial mount got a reference on this
425 		 * device, so drop the one obtained via
426 		 * namei(), above.
427 		 */
428 		vrele(devvp);
429 
430 		ump = VFSTOUFS(mp);
431 		fs = ump->um_e2fs;
432 		if (fs->e2fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
433 			/*
434 			 * Changing from r/w to r/o
435 			 */
436 			flags = WRITECLOSE;
437 			if (mp->mnt_flag & MNT_FORCE)
438 				flags |= FORCECLOSE;
439 			error = ext2fs_flushfiles(mp, flags);
440 			if (error == 0 &&
441 			    ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
442 			    (fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
443 				fs->e2fs.e2fs_state = E2FS_ISCLEAN;
444 				(void) ext2fs_sbupdate(ump, MNT_WAIT);
445 			}
446 			if (error)
447 				return (error);
448 			fs->e2fs_ronly = 1;
449 		}
450 
451 		if (mp->mnt_flag & MNT_RELOAD) {
452 			error = ext2fs_reload(mp, l->l_cred, l);
453 			if (error)
454 				return (error);
455 		}
456 
457 		if (fs->e2fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR)) {
458 			/*
459 			 * Changing from read-only to read/write
460 			 */
461 			fs->e2fs_ronly = 0;
462 			if (fs->e2fs.e2fs_state == E2FS_ISCLEAN)
463 				fs->e2fs.e2fs_state = 0;
464 			else
465 				fs->e2fs.e2fs_state = E2FS_ERRORS;
466 			fs->e2fs_fmod = 1;
467 		}
468 		if (args->fspec == NULL)
469 			return 0;
470 	}
471 
472 	error = set_statvfs_info(path, UIO_USERSPACE, args->fspec,
473 	    UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
474 	(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs_fsmnt,
475 	    sizeof(fs->e2fs_fsmnt) - 1, &size);
476 	memset(fs->e2fs_fsmnt + size, 0, sizeof(fs->e2fs_fsmnt) - size);
477 	if (fs->e2fs.e2fs_rev > E2FS_REV0) {
478 		(void) copystr(mp->mnt_stat.f_mntonname, fs->e2fs.e2fs_fsmnt,
479 		    sizeof(fs->e2fs.e2fs_fsmnt) - 1, &size);
480 		memset(fs->e2fs.e2fs_fsmnt, 0,
481 		    sizeof(fs->e2fs.e2fs_fsmnt) - size);
482 	}
483 	if (fs->e2fs_fmod != 0) {	/* XXX */
484 		fs->e2fs_fmod = 0;
485 		if (fs->e2fs.e2fs_state == 0)
486 			fs->e2fs.e2fs_wtime = time_second;
487 		else
488 			printf("%s: file system not clean; please fsck(8)\n",
489 				mp->mnt_stat.f_mntfromname);
490 		(void) ext2fs_cgupdate(ump, MNT_WAIT);
491 	}
492 	return (error);
493 
494 fail:
495 	vrele(devvp);
496 	return (error);
497 }
498 
499 /*
500  * Reload all incore data for a filesystem (used after running fsck on
501  * the root filesystem and finding things to fix). The filesystem must
502  * be mounted read-only.
503  *
504  * Things to do to update the mount:
505  *	1) invalidate all cached meta-data.
506  *	2) re-read superblock from disk.
507  *	3) re-read summary information from disk.
508  *	4) invalidate all inactive vnodes.
509  *	5) invalidate all cached file data.
510  *	6) re-read inode data for all active vnodes.
511  */
512 int
ext2fs_reload(struct mount * mp,kauth_cred_t cred,struct lwp * l)513 ext2fs_reload(struct mount *mp, kauth_cred_t cred, struct lwp *l)
514 {
515 	struct vnode *vp, *devvp;
516 	struct inode *ip;
517 	struct buf *bp;
518 	struct m_ext2fs *fs;
519 	struct ext2fs *newfs;
520 	int i, error;
521 	void *cp;
522 	struct ufsmount *ump;
523 	struct vnode_iterator *marker;
524 
525 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
526 		return (EINVAL);
527 
528 	ump = VFSTOUFS(mp);
529 	/*
530 	 * Step 1: invalidate all cached meta-data.
531 	 */
532 	devvp = ump->um_devvp;
533 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
534 	error = vinvalbuf(devvp, 0, cred, l, 0, 0);
535 	VOP_UNLOCK(devvp);
536 	if (error)
537 		panic("ext2fs_reload: dirty1");
538 
539 	fs = ump->um_e2fs;
540 	/*
541 	 * Step 2: re-read superblock from disk. Copy in new superblock, and compute
542 	 * in-memory values.
543 	 */
544 	error = bread(devvp, SBLOCK, SBSIZE, 0, &bp);
545 	if (error)
546 		return error;
547 	newfs = (struct ext2fs *)bp->b_data;
548 	e2fs_sbload(newfs, &fs->e2fs);
549 
550 	brelse(bp, 0);
551 
552 	error = ext2fs_sbfill(fs, (mp->mnt_flag & MNT_RDONLY) != 0);
553 	if (error)
554 		return error;
555 
556 	/*
557 	 * Step 3: re-read summary information from disk.
558 	 */
559 	for (i = 0; i < fs->e2fs_ngdb; i++) {
560 		error = bread(devvp ,
561 		    EXT2_FSBTODB(fs, fs->e2fs.e2fs_first_dblock +
562 		    1 /* superblock */ + i),
563 		    fs->e2fs_bsize, 0, &bp);
564 		if (error) {
565 			return (error);
566 		}
567 		e2fs_cgload((struct ext2_gd *)bp->b_data,
568 		    &fs->e2fs_gd[i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
569 		    fs->e2fs_bsize);
570 		brelse(bp, 0);
571 	}
572 
573 	vfs_vnode_iterator_init(mp, &marker);
574 	while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL))) {
575 		/*
576 		 * Step 4: invalidate all inactive vnodes.
577 		 */
578 		if (vrecycle(vp))
579 			continue;
580 		/*
581 		 * Step 5: invalidate all cached file data.
582 		 */
583 		if (vn_lock(vp, LK_EXCLUSIVE)) {
584 			vrele(vp);
585 			continue;
586 		}
587 		if (vinvalbuf(vp, 0, cred, l, 0, 0))
588 			panic("ext2fs_reload: dirty2");
589 		/*
590 		 * Step 6: re-read inode data for all active vnodes.
591 		 */
592 		ip = VTOI(vp);
593 		error = bread(devvp, EXT2_FSBTODB(fs, ino_to_fsba(fs, ip->i_number)),
594 		    (int)fs->e2fs_bsize, 0, &bp);
595 		if (error) {
596 			vput(vp);
597 			break;
598 		}
599 		cp = (char *)bp->b_data +
600 		    (ino_to_fsbo(fs, ip->i_number) * EXT2_DINODE_SIZE(fs));
601 		e2fs_iload((struct ext2fs_dinode *)cp, ip->i_din.e2fs_din);
602 		ext2fs_set_inode_guid(ip);
603 		brelse(bp, 0);
604 		vput(vp);
605 	}
606 	vfs_vnode_iterator_destroy(marker);
607 	return (error);
608 }
609 
610 /*
611  * Common code for mount and mountroot
612  */
613 int
ext2fs_mountfs(struct vnode * devvp,struct mount * mp)614 ext2fs_mountfs(struct vnode *devvp, struct mount *mp)
615 {
616 	struct lwp *l = curlwp;
617 	struct ufsmount *ump;
618 	struct buf *bp;
619 	struct ext2fs *fs;
620 	struct m_ext2fs *m_fs;
621 	dev_t dev;
622 	int error, i, ronly;
623 	kauth_cred_t cred;
624 
625 	dev = devvp->v_rdev;
626 	cred = l->l_cred;
627 
628 	/* Flush out any old buffers remaining from a previous use. */
629 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
630 	error = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0);
631 	VOP_UNLOCK(devvp);
632 	if (error)
633 		return (error);
634 
635 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
636 
637 	bp = NULL;
638 	ump = NULL;
639 
640 	/* Read the superblock from disk, and swap it directly. */
641 	error = bread(devvp, SBLOCK, SBSIZE, 0, &bp);
642 	if (error)
643 		goto out;
644 	fs = (struct ext2fs *)bp->b_data;
645 	m_fs = kmem_zalloc(sizeof(struct m_ext2fs), KM_SLEEP);
646 	e2fs_sbload(fs, &m_fs->e2fs);
647 
648 	brelse(bp, 0);
649 	bp = NULL;
650 
651 	/* Once swapped, validate and fill in the superblock. */
652 	error = ext2fs_sbfill(m_fs, ronly);
653 	if (error) {
654 		kmem_free(m_fs, sizeof(struct m_ext2fs));
655 		goto out;
656 	}
657 	m_fs->e2fs_ronly = ronly;
658 
659 	ump = kmem_zalloc(sizeof(*ump), KM_SLEEP);
660 	ump->um_fstype = UFS1;
661 	ump->um_ops = &ext2fs_ufsops;
662 	ump->um_e2fs = m_fs;
663 
664 	if (ronly == 0) {
665 		if (m_fs->e2fs.e2fs_state == E2FS_ISCLEAN)
666 			m_fs->e2fs.e2fs_state = 0;
667 		else
668 			m_fs->e2fs.e2fs_state = E2FS_ERRORS;
669 		m_fs->e2fs_fmod = 1;
670 	}
671 
672 	/* XXX: should be added in ext2fs_sbfill()? */
673 	m_fs->e2fs_gd = kmem_alloc(m_fs->e2fs_ngdb * m_fs->e2fs_bsize, KM_SLEEP);
674 	for (i = 0; i < m_fs->e2fs_ngdb; i++) {
675 		error = bread(devvp,
676 		    EXT2_FSBTODB(m_fs, m_fs->e2fs.e2fs_first_dblock +
677 		    1 /* superblock */ + i),
678 		    m_fs->e2fs_bsize, 0, &bp);
679 		if (error) {
680 			kmem_free(m_fs->e2fs_gd,
681 			    m_fs->e2fs_ngdb * m_fs->e2fs_bsize);
682 			goto out;
683 		}
684 		e2fs_cgload((struct ext2_gd *)bp->b_data,
685 		    &m_fs->e2fs_gd[
686 			i * m_fs->e2fs_bsize / sizeof(struct ext2_gd)],
687 		    m_fs->e2fs_bsize);
688 		brelse(bp, 0);
689 		bp = NULL;
690 	}
691 
692 	mp->mnt_data = ump;
693 	mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
694 	mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_EXT2FS);
695 	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
696 	mp->mnt_stat.f_namemax = EXT2FS_MAXNAMLEN;
697 	mp->mnt_flag |= MNT_LOCAL;
698 	mp->mnt_dev_bshift = DEV_BSHIFT;	/* XXX */
699 	mp->mnt_fs_bshift = m_fs->e2fs_bshift;
700 	mp->mnt_iflag |= IMNT_DTYPE;
701 	ump->um_flags = 0;
702 	ump->um_mountp = mp;
703 	ump->um_dev = dev;
704 	ump->um_devvp = devvp;
705 	ump->um_nindir = EXT2_NINDIR(m_fs);
706 	ump->um_lognindir = ffs(EXT2_NINDIR(m_fs)) - 1;
707 	ump->um_bptrtodb = m_fs->e2fs_fsbtodb;
708 	ump->um_seqinc = 1; /* no frags */
709 	ump->um_maxsymlinklen = EXT2_MAXSYMLINKLEN;
710 	ump->um_dirblksiz = m_fs->e2fs_bsize;
711 	ump->um_maxfilesize = ((uint64_t)0x80000000 * m_fs->e2fs_bsize - 1);
712 	spec_node_setmountedfs(devvp, mp);
713 	return (0);
714 
715 out:
716 	if (bp != NULL)
717 		brelse(bp, 0);
718 	if (ump) {
719 		kmem_free(ump->um_e2fs, sizeof(struct m_ext2fs));
720 		kmem_free(ump, sizeof(*ump));
721 		mp->mnt_data = NULL;
722 	}
723 	return (error);
724 }
725 
726 /*
727  * unmount system call
728  */
729 int
ext2fs_unmount(struct mount * mp,int mntflags)730 ext2fs_unmount(struct mount *mp, int mntflags)
731 {
732 	struct ufsmount *ump;
733 	struct m_ext2fs *fs;
734 	int error, flags;
735 
736 	flags = 0;
737 	if (mntflags & MNT_FORCE)
738 		flags |= FORCECLOSE;
739 	if ((error = ext2fs_flushfiles(mp, flags)) != 0)
740 		return (error);
741 	ump = VFSTOUFS(mp);
742 	fs = ump->um_e2fs;
743 	if (fs->e2fs_ronly == 0 &&
744 		ext2fs_cgupdate(ump, MNT_WAIT) == 0 &&
745 		(fs->e2fs.e2fs_state & E2FS_ERRORS) == 0) {
746 		fs->e2fs.e2fs_state = E2FS_ISCLEAN;
747 		(void) ext2fs_sbupdate(ump, MNT_WAIT);
748 	}
749 	if (ump->um_devvp->v_type != VBAD)
750 		spec_node_setmountedfs(ump->um_devvp, NULL);
751 	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
752 	error = VOP_CLOSE(ump->um_devvp, fs->e2fs_ronly ? FREAD : FREAD|FWRITE,
753 	    NOCRED);
754 	vput(ump->um_devvp);
755 	kmem_free(fs->e2fs_gd, fs->e2fs_ngdb * fs->e2fs_bsize);
756 	kmem_free(fs, sizeof(*fs));
757 	kmem_free(ump, sizeof(*ump));
758 	mp->mnt_data = NULL;
759 	mp->mnt_flag &= ~MNT_LOCAL;
760 	return (error);
761 }
762 
763 /*
764  * Flush out all the files in a filesystem.
765  */
766 int
ext2fs_flushfiles(struct mount * mp,int flags)767 ext2fs_flushfiles(struct mount *mp, int flags)
768 {
769 	extern int doforce;
770 	int error;
771 
772 	if (!doforce)
773 		flags &= ~FORCECLOSE;
774 	error = vflush(mp, NULLVP, flags);
775 	return (error);
776 }
777 
778 /*
779  * Get file system statistics.
780  */
781 int
ext2fs_statvfs(struct mount * mp,struct statvfs * sbp)782 ext2fs_statvfs(struct mount *mp, struct statvfs *sbp)
783 {
784 	struct ufsmount *ump;
785 	struct m_ext2fs *fs;
786 	uint32_t overhead, overhead_per_group, ngdb;
787 	int i, ngroups;
788 
789 	ump = VFSTOUFS(mp);
790 	fs = ump->um_e2fs;
791 	if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
792 		panic("ext2fs_statvfs");
793 
794 	/*
795 	 * Compute the overhead (FS structures)
796 	 */
797 	overhead_per_group =
798 	    1 /* block bitmap */ +
799 	    1 /* inode bitmap */ +
800 	    fs->e2fs_itpg;
801 	overhead = fs->e2fs.e2fs_first_dblock +
802 	    fs->e2fs_ncg * overhead_per_group;
803 	if (fs->e2fs.e2fs_rev > E2FS_REV0 &&
804 	    fs->e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
805 		for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
806 			if (cg_has_sb(i))
807 				ngroups++;
808 		}
809 	} else {
810 		ngroups = fs->e2fs_ncg;
811 	}
812 	ngdb = fs->e2fs_ngdb;
813 	if (fs->e2fs.e2fs_rev > E2FS_REV0 &&
814 	    fs->e2fs.e2fs_features_compat & EXT2F_COMPAT_RESIZE)
815 		ngdb += fs->e2fs.e2fs_reserved_ngdb;
816 	overhead += ngroups * (1 /* superblock */ + ngdb);
817 
818 	sbp->f_bsize = fs->e2fs_bsize;
819 	sbp->f_frsize = MINBSIZE << fs->e2fs.e2fs_fsize;
820 	sbp->f_iosize = fs->e2fs_bsize;
821 	sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
822 	sbp->f_bfree = fs->e2fs.e2fs_fbcount;
823 	sbp->f_bresvd = fs->e2fs.e2fs_rbcount;
824 	if (sbp->f_bfree > sbp->f_bresvd)
825 		sbp->f_bavail = sbp->f_bfree - sbp->f_bresvd;
826 	else
827 		sbp->f_bavail = 0;
828 	sbp->f_files =  fs->e2fs.e2fs_icount;
829 	sbp->f_ffree = fs->e2fs.e2fs_ficount;
830 	sbp->f_favail = fs->e2fs.e2fs_ficount;
831 	sbp->f_fresvd = 0;
832 	copy_statvfs_info(sbp, mp);
833 	return (0);
834 }
835 
836 static bool
ext2fs_sync_selector(void * cl,struct vnode * vp)837 ext2fs_sync_selector(void *cl, struct vnode *vp)
838 {
839 	struct inode *ip;
840 
841 	ip = VTOI(vp);
842 	/*
843 	 * Skip the vnode/inode if inaccessible.
844 	 */
845 	if (ip == NULL || vp->v_type == VNON)
846 		return false;
847 
848 	if (((ip->i_flag &
849 	      (IN_CHANGE | IN_UPDATE | IN_MODIFIED)) == 0 &&
850 	     LIST_EMPTY(&vp->v_dirtyblkhd) &&
851 	     UVM_OBJ_IS_CLEAN(&vp->v_uobj)))
852 		return false;
853 	return true;
854 }
855 
856 /*
857  * Go through the disk queues to initiate sandbagged IO;
858  * go through the inodes to write those that have been modified;
859  * initiate the writing of the super block if it has been modified.
860  *
861  * Note: we are always called with the filesystem marked `MPBUSY'.
862  */
863 int
ext2fs_sync(struct mount * mp,int waitfor,kauth_cred_t cred)864 ext2fs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
865 {
866 	struct vnode *vp;
867 	struct ufsmount *ump = VFSTOUFS(mp);
868 	struct m_ext2fs *fs;
869 	struct vnode_iterator *marker;
870 	int error, allerror = 0;
871 
872 	fs = ump->um_e2fs;
873 	if (fs->e2fs_fmod != 0 && fs->e2fs_ronly != 0) {	/* XXX */
874 		printf("fs = %s\n", fs->e2fs_fsmnt);
875 		panic("update: rofs mod");
876 	}
877 
878 	/*
879 	 * Write back each (modified) inode.
880 	 */
881 	vfs_vnode_iterator_init(mp, &marker);
882 	while ((vp = vfs_vnode_iterator_next(marker, ext2fs_sync_selector,
883 	    NULL)))
884 	{
885 		error = vn_lock(vp, LK_EXCLUSIVE);
886 		if (error) {
887 			vrele(vp);
888 			continue;
889 		}
890 		if (vp->v_type == VREG && waitfor == MNT_LAZY)
891 			error = ext2fs_update(vp, NULL, NULL, 0);
892 		else
893 			error = VOP_FSYNC(vp, cred,
894 			    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0);
895 		if (error)
896 			allerror = error;
897 		vput(vp);
898 	}
899 	vfs_vnode_iterator_destroy(marker);
900 	/*
901 	 * Force stale file system control information to be flushed.
902 	 */
903 	if (waitfor != MNT_LAZY) {
904 		vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
905 		if ((error = VOP_FSYNC(ump->um_devvp, cred,
906 		    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
907 			allerror = error;
908 		VOP_UNLOCK(ump->um_devvp);
909 	}
910 	/*
911 	 * Write back modified superblock.
912 	 */
913 	if (fs->e2fs_fmod != 0) {
914 		fs->e2fs_fmod = 0;
915 		fs->e2fs.e2fs_wtime = time_second;
916 		if ((error = ext2fs_cgupdate(ump, waitfor)))
917 			allerror = error;
918 	}
919 	return (allerror);
920 }
921 
922 /*
923  * Read an inode from disk and initialize this vnode / inode pair.
924  * Caller assures no other thread will try to load this inode.
925  */
926 int
ext2fs_loadvnode(struct mount * mp,struct vnode * vp,const void * key,size_t key_len,const void ** new_key)927 ext2fs_loadvnode(struct mount *mp, struct vnode *vp,
928     const void *key, size_t key_len, const void **new_key)
929 {
930 	ino_t ino;
931 	struct m_ext2fs *fs;
932 	struct inode *ip;
933 	struct ufsmount *ump;
934 	struct buf *bp;
935 	dev_t dev;
936 	int error;
937 	void *cp;
938 
939 	KASSERT(key_len == sizeof(ino));
940 	memcpy(&ino, key, key_len);
941 	ump = VFSTOUFS(mp);
942 	dev = ump->um_dev;
943 	fs = ump->um_e2fs;
944 
945 	/* Read in the disk contents for the inode, copy into the inode. */
946 	error = bread(ump->um_devvp, EXT2_FSBTODB(fs, ino_to_fsba(fs, ino)),
947 	    (int)fs->e2fs_bsize, 0, &bp);
948 	if (error)
949 		return error;
950 
951 	/* Allocate and initialize inode. */
952 	ip = pool_get(&ext2fs_inode_pool, PR_WAITOK);
953 	memset(ip, 0, sizeof(struct inode));
954 	vp->v_tag = VT_EXT2FS;
955 	vp->v_op = ext2fs_vnodeop_p;
956 	vp->v_vflag |= VV_LOCKSWORK;
957 	vp->v_data = ip;
958 	ip->i_vnode = vp;
959 	ip->i_ump = ump;
960 	ip->i_e2fs = fs;
961 	ip->i_dev = dev;
962 	ip->i_number = ino;
963 	ip->i_e2fs_last_lblk = 0;
964 	ip->i_e2fs_last_blk = 0;
965 
966 	/* Initialize genfs node. */
967 	genfs_node_init(vp, &ext2fs_genfsops);
968 
969 	cp = (char *)bp->b_data + (ino_to_fsbo(fs, ino) * EXT2_DINODE_SIZE(fs));
970 	ip->i_din.e2fs_din = pool_get(&ext2fs_dinode_pool, PR_WAITOK);
971 	e2fs_iload((struct ext2fs_dinode *)cp, ip->i_din.e2fs_din);
972 	ext2fs_set_inode_guid(ip);
973 	brelse(bp, 0);
974 
975 	/* If the inode was deleted, reset all fields */
976 	if (ip->i_e2fs_dtime != 0) {
977 		ip->i_e2fs_mode = 0;
978 		(void)ext2fs_setsize(ip, 0);
979 		(void)ext2fs_setnblock(ip, 0);
980 		memset(ip->i_e2fs_blocks, 0, sizeof(ip->i_e2fs_blocks));
981 	}
982 
983 	/* Initialize the vnode from the inode. */
984 	ext2fs_vinit(mp, ext2fs_specop_p, ext2fs_fifoop_p, &vp);
985 
986 	/* Finish inode initialization. */
987 	ip->i_devvp = ump->um_devvp;
988 	vref(ip->i_devvp);
989 
990 	/*
991 	 * Set up a generation number for this inode if it does not
992 	 * already have one. This should only happen on old filesystems.
993 	 */
994 
995 	if (ip->i_e2fs_gen == 0) {
996 		if (++ext2gennumber < (u_long)time_second)
997 			ext2gennumber = time_second;
998 		ip->i_e2fs_gen = ext2gennumber;
999 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
1000 			ip->i_flag |= IN_MODIFIED;
1001 	}
1002 	uvm_vnp_setsize(vp, ext2fs_size(ip));
1003 	*new_key = &ip->i_number;
1004 	return 0;
1005 }
1006 
1007 /*
1008  * File handle to vnode
1009  *
1010  * Have to be really careful about stale file handles:
1011  * - check that the inode number is valid
1012  * - call ext2fs_vget() to get the locked inode
1013  * - check for an unallocated inode (i_mode == 0)
1014  */
1015 int
ext2fs_fhtovp(struct mount * mp,struct fid * fhp,struct vnode ** vpp)1016 ext2fs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
1017 {
1018 	struct inode *ip;
1019 	struct vnode *nvp;
1020 	int error;
1021 	struct ufid ufh;
1022 	struct m_ext2fs *fs;
1023 
1024 	if (fhp->fid_len != sizeof(struct ufid))
1025 		return EINVAL;
1026 
1027 	memcpy(&ufh, fhp, sizeof(struct ufid));
1028 	fs = VFSTOUFS(mp)->um_e2fs;
1029 	if ((ufh.ufid_ino < EXT2_FIRSTINO && ufh.ufid_ino != EXT2_ROOTINO) ||
1030 		ufh.ufid_ino >= fs->e2fs_ncg * fs->e2fs.e2fs_ipg)
1031 		return (ESTALE);
1032 
1033 	if ((error = VFS_VGET(mp, ufh.ufid_ino, &nvp)) != 0) {
1034 		*vpp = NULLVP;
1035 		return (error);
1036 	}
1037 	ip = VTOI(nvp);
1038 	if (ip->i_e2fs_mode == 0 || ip->i_e2fs_dtime != 0 ||
1039 		ip->i_e2fs_gen != ufh.ufid_gen) {
1040 		vput(nvp);
1041 		*vpp = NULLVP;
1042 		return (ESTALE);
1043 	}
1044 	*vpp = nvp;
1045 	return (0);
1046 }
1047 
1048 /*
1049  * Vnode pointer to File handle
1050  */
1051 /* ARGSUSED */
1052 int
ext2fs_vptofh(struct vnode * vp,struct fid * fhp,size_t * fh_size)1053 ext2fs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
1054 {
1055 	struct inode *ip;
1056 	struct ufid ufh;
1057 
1058 	if (*fh_size < sizeof(struct ufid)) {
1059 		*fh_size = sizeof(struct ufid);
1060 		return E2BIG;
1061 	}
1062 	*fh_size = sizeof(struct ufid);
1063 
1064 	ip = VTOI(vp);
1065 	memset(&ufh, 0, sizeof(ufh));
1066 	ufh.ufid_len = sizeof(struct ufid);
1067 	ufh.ufid_ino = ip->i_number;
1068 	ufh.ufid_gen = ip->i_e2fs_gen;
1069 	memcpy(fhp, &ufh, sizeof(ufh));
1070 	return (0);
1071 }
1072 
1073 /*
1074  * Write a superblock and associated information back to disk.
1075  */
1076 int
ext2fs_sbupdate(struct ufsmount * mp,int waitfor)1077 ext2fs_sbupdate(struct ufsmount *mp, int waitfor)
1078 {
1079 	struct m_ext2fs *fs = mp->um_e2fs;
1080 	struct buf *bp;
1081 	int error = 0;
1082 
1083 	bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, 0);
1084 	e2fs_sbsave(&fs->e2fs, (struct ext2fs*)bp->b_data);
1085 	if (waitfor == MNT_WAIT)
1086 		error = bwrite(bp);
1087 	else
1088 		bawrite(bp);
1089 	return (error);
1090 }
1091 
1092 int
ext2fs_cgupdate(struct ufsmount * mp,int waitfor)1093 ext2fs_cgupdate(struct ufsmount *mp, int waitfor)
1094 {
1095 	struct m_ext2fs *fs = mp->um_e2fs;
1096 	struct buf *bp;
1097 	int i, error = 0, allerror = 0;
1098 
1099 	allerror = ext2fs_sbupdate(mp, waitfor);
1100 	for (i = 0; i < fs->e2fs_ngdb; i++) {
1101 		bp = getblk(mp->um_devvp, EXT2_FSBTODB(fs,
1102 		    fs->e2fs.e2fs_first_dblock +
1103 		    1 /* superblock */ + i), fs->e2fs_bsize, 0, 0);
1104 		e2fs_cgsave(&fs->e2fs_gd[
1105 		    i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
1106 		    (struct ext2_gd *)bp->b_data, fs->e2fs_bsize);
1107 		if (waitfor == MNT_WAIT)
1108 			error = bwrite(bp);
1109 		else
1110 			bawrite(bp);
1111 	}
1112 
1113 	if (!allerror && error)
1114 		allerror = error;
1115 	return (allerror);
1116 }
1117 
1118 /*
1119  * Fill in the m_fs structure, and validate the fields of the superblock.
1120  * NOTE: here, the superblock is already swapped.
1121  */
1122 static int
ext2fs_sbfill(struct m_ext2fs * m_fs,int ronly)1123 ext2fs_sbfill(struct m_ext2fs *m_fs, int ronly)
1124 {
1125 	uint32_t u32;
1126 	struct ext2fs *fs = &m_fs->e2fs;
1127 
1128 	/*
1129 	 * General sanity checks
1130 	 */
1131 	if (fs->e2fs_magic != E2FS_MAGIC)
1132 		return EINVAL;
1133 	if (fs->e2fs_rev > E2FS_REV1) {
1134 		printf("ext2fs: unsupported revision number: %x\n", fs->e2fs_rev);
1135 		return EINVAL;
1136 	}
1137 	if (fs->e2fs_log_bsize > 2) {
1138 		/* block size = 1024|2048|4096 */
1139 		printf("ext2fs: bad block size: %d\n", fs->e2fs_log_bsize);
1140 		return EINVAL;
1141 	}
1142 	if (fs->e2fs_bpg == 0) {
1143 		printf("ext2fs: zero blocks per group\n");
1144 		return EINVAL;
1145 	}
1146 	if (fs->e2fs_ipg == 0) {
1147 		printf("ext2fs: zero inodes per group\n");
1148 		return EINVAL;
1149 	}
1150 
1151 	if (fs->e2fs_first_dblock >= fs->e2fs_bcount) {
1152 		printf("ext2fs: invalid first data block\n");
1153 		return EINVAL;
1154 	}
1155 	if (fs->e2fs_rbcount > fs->e2fs_bcount ||
1156 	    fs->e2fs_fbcount > fs->e2fs_bcount) {
1157 		printf("ext2fs: invalid block count\n");
1158 		return EINVAL;
1159 	}
1160 
1161 	/*
1162 	 * Revision-specific checks
1163 	 */
1164 	if (fs->e2fs_rev > E2FS_REV0) {
1165 		char buf[256];
1166 		if (fs->e2fs_first_ino != EXT2_FIRSTINO) {
1167 			printf("ext2fs: unsupported first inode position\n");
1168 			return EINVAL;
1169 		}
1170 		u32 = fs->e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP;
1171 		if (u32) {
1172 			snprintb(buf, sizeof(buf), EXT2F_INCOMPAT_BITS, u32);
1173 			printf("ext2fs: unsupported incompat features: %s\n", buf);
1174 			return EINVAL;
1175 		}
1176 		u32 = fs->e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP;
1177 		if (!ronly && u32) {
1178 			snprintb(buf, sizeof(buf), EXT2F_ROCOMPAT_BITS, u32);
1179 			printf("ext2fs: unsupported ro-incompat features: %s\n",
1180 			    buf);
1181 			return EROFS;
1182 		}
1183 		if (fs->e2fs_inode_size == 0 || !powerof2(fs->e2fs_inode_size)) {
1184 			printf("ext2fs: bad inode size\n");
1185 			return EINVAL;
1186 		}
1187 	}
1188 
1189 	/*
1190 	 * Compute the fields of the superblock
1191 	 */
1192 	u32 = fs->e2fs_bcount - fs->e2fs_first_dblock; /* > 0 */
1193 	m_fs->e2fs_ncg = howmany(u32, fs->e2fs_bpg);
1194 	if (m_fs->e2fs_ncg == 0) {
1195 		printf("ext2fs: invalid number of cylinder groups\n");
1196 		return EINVAL;
1197 	}
1198 
1199 	m_fs->e2fs_fsbtodb = fs->e2fs_log_bsize + LOG_MINBSIZE - DEV_BSHIFT;
1200 	m_fs->e2fs_bsize = MINBSIZE << fs->e2fs_log_bsize;
1201 	m_fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs_log_bsize;
1202 	m_fs->e2fs_qbmask = m_fs->e2fs_bsize - 1;
1203 	m_fs->e2fs_bmask = ~m_fs->e2fs_qbmask;
1204 
1205 	if ((u32 = m_fs->e2fs_bsize / sizeof(struct ext2_gd)) == 0) {
1206 		/* Unlikely to happen */
1207 		printf("ext2fs: invalid block size\n");
1208 		return EINVAL;
1209 	}
1210 	m_fs->e2fs_ngdb = howmany(m_fs->e2fs_ncg, u32);
1211 	if (m_fs->e2fs_ngdb == 0) {
1212 		printf("ext2fs: invalid number of group descriptor blocks\n");
1213 		return EINVAL;
1214 	}
1215 
1216 	if (m_fs->e2fs_bsize < EXT2_DINODE_SIZE(m_fs)) {
1217 		printf("ext2fs: invalid inode size\n");
1218 		return EINVAL;
1219 	}
1220 	m_fs->e2fs_ipb = m_fs->e2fs_bsize / EXT2_DINODE_SIZE(m_fs);
1221 
1222 	m_fs->e2fs_itpg = fs->e2fs_ipg / m_fs->e2fs_ipb;
1223 
1224 	return 0;
1225 }
1226