xref: /freebsd/sys/fs/ext2fs/ext2_vfsops.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc)
1 /*-
2  *  modified for EXT2FS support in Lites 1.1
3  *
4  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
5  *  University of Utah, Department of Computer Science
6  */
7 /*-
8  * Copyright (c) 1989, 1991, 1993, 1994
9  *	The Regents of the University of California.  All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)ffs_vfsops.c	8.8 (Berkeley) 4/18/94
36  * $FreeBSD$
37  */
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/namei.h>
42 #include <sys/priv.h>
43 #include <sys/proc.h>
44 #include <sys/kernel.h>
45 #include <sys/vnode.h>
46 #include <sys/mount.h>
47 #include <sys/bio.h>
48 #include <sys/buf.h>
49 #include <sys/conf.h>
50 #include <sys/endian.h>
51 #include <sys/fcntl.h>
52 #include <sys/malloc.h>
53 #include <sys/stat.h>
54 #include <sys/mutex.h>
55 
56 #include <geom/geom.h>
57 #include <geom/geom_vfs.h>
58 
59 #include <fs/ext2fs/ext2_mount.h>
60 #include <fs/ext2fs/inode.h>
61 
62 #include <fs/ext2fs/fs.h>
63 #include <fs/ext2fs/ext2fs.h>
64 #include <fs/ext2fs/ext2_dinode.h>
65 #include <fs/ext2fs/ext2_extern.h>
66 
67 static int	ext2_flushfiles(struct mount *mp, int flags, struct thread *td);
68 static int	ext2_mountfs(struct vnode *, struct mount *);
69 static int	ext2_reload(struct mount *mp, struct thread *td);
70 static int	ext2_sbupdate(struct ext2mount *, int);
71 static int	ext2_cgupdate(struct ext2mount *, int);
72 static vfs_unmount_t		ext2_unmount;
73 static vfs_root_t		ext2_root;
74 static vfs_statfs_t		ext2_statfs;
75 static vfs_sync_t		ext2_sync;
76 static vfs_vget_t		ext2_vget;
77 static vfs_fhtovp_t		ext2_fhtovp;
78 static vfs_mount_t		ext2_mount;
79 
80 MALLOC_DEFINE(M_EXT2NODE, "ext2_node", "EXT2 vnode private part");
81 static MALLOC_DEFINE(M_EXT2MNT, "ext2_mount", "EXT2 mount structure");
82 
83 static struct vfsops ext2fs_vfsops = {
84 	.vfs_fhtovp =		ext2_fhtovp,
85 	.vfs_mount =		ext2_mount,
86 	.vfs_root =		ext2_root,	/* root inode via vget */
87 	.vfs_statfs =		ext2_statfs,
88 	.vfs_sync =		ext2_sync,
89 	.vfs_unmount =		ext2_unmount,
90 	.vfs_vget =		ext2_vget,
91 };
92 
93 VFS_SET(ext2fs_vfsops, ext2fs, 0);
94 
95 static int	ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev,
96 		    int ronly);
97 static int	compute_sb_data(struct vnode * devvp,
98 		    struct ext2fs * es, struct m_ext2fs * fs);
99 
100 static const char *ext2_opts[] = { "acls", "async", "noatime", "noclusterr",
101     "noclusterw", "noexec", "export", "force", "from", "multilabel",
102     "suiddir", "nosymfollow", "sync", "union", NULL };
103 
104 /*
105  * VFS Operations.
106  *
107  * mount system call
108  */
109 static int
110 ext2_mount(struct mount *mp)
111 {
112 	struct vfsoptlist *opts;
113 	struct vnode *devvp;
114 	struct thread *td;
115 	struct ext2mount *ump = NULL;
116 	struct m_ext2fs *fs;
117 	struct nameidata nd, *ndp = &nd;
118 	accmode_t accmode;
119 	char *path, *fspec;
120 	int error, flags, len;
121 
122 	td = curthread;
123 	opts = mp->mnt_optnew;
124 
125 	if (vfs_filteropt(opts, ext2_opts))
126 		return (EINVAL);
127 
128 	vfs_getopt(opts, "fspath", (void **)&path, NULL);
129 	/* Double-check the length of path.. */
130 	if (strlen(path) >= MAXMNTLEN)
131 		return (ENAMETOOLONG);
132 
133 	fspec = NULL;
134 	error = vfs_getopt(opts, "from", (void **)&fspec, &len);
135 	if (!error && fspec[len - 1] != '\0')
136 		return (EINVAL);
137 
138 	/*
139 	 * If updating, check whether changing from read-only to
140 	 * read/write; if there is no device name, that's all we do.
141 	 */
142 	if (mp->mnt_flag & MNT_UPDATE) {
143 		ump = VFSTOEXT2(mp);
144 		fs = ump->um_e2fs;
145 		error = 0;
146 		if (fs->e2fs_ronly == 0 &&
147 		    vfs_flagopt(opts, "ro", NULL, 0)) {
148 			error = VFS_SYNC(mp, MNT_WAIT);
149 			if (error)
150 				return (error);
151 			flags = WRITECLOSE;
152 			if (mp->mnt_flag & MNT_FORCE)
153 				flags |= FORCECLOSE;
154 			error = ext2_flushfiles(mp, flags, td);
155 			if ( error == 0 && fs->e2fs_wasvalid && ext2_cgupdate(ump, MNT_WAIT) == 0) {
156 				fs->e2fs->e2fs_state |= E2FS_ISCLEAN;
157 				ext2_sbupdate(ump, MNT_WAIT);
158 			}
159 			fs->e2fs_ronly = 1;
160 			vfs_flagopt(opts, "ro", &mp->mnt_flag, MNT_RDONLY);
161 			g_topology_lock();
162 			g_access(ump->um_cp, 0, -1, 0);
163 			g_topology_unlock();
164 		}
165 		if (!error && (mp->mnt_flag & MNT_RELOAD))
166 			error = ext2_reload(mp, td);
167 		if (error)
168 			return (error);
169 		devvp = ump->um_devvp;
170 		if (fs->e2fs_ronly && !vfs_flagopt(opts, "ro", NULL, 0)) {
171 			if (ext2_check_sb_compat(fs->e2fs, devvp->v_rdev, 0))
172 				return (EPERM);
173 
174 			/*
175 			 * If upgrade to read-write by non-root, then verify
176 			 * that user has necessary permissions on the device.
177 			 */
178 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
179 			error = VOP_ACCESS(devvp, VREAD | VWRITE,
180 			    td->td_ucred, td);
181 			if (error)
182 				error = priv_check(td, PRIV_VFS_MOUNT_PERM);
183 			if (error) {
184 				VOP_UNLOCK(devvp, 0);
185 				return (error);
186 			}
187 			VOP_UNLOCK(devvp, 0);
188 			g_topology_lock();
189 			error = g_access(ump->um_cp, 0, 1, 0);
190 			g_topology_unlock();
191 			if (error)
192 				return (error);
193 
194 			if ((fs->e2fs->e2fs_state & E2FS_ISCLEAN) == 0 ||
195 			    (fs->e2fs->e2fs_state & E2FS_ERRORS)) {
196 				if (mp->mnt_flag & MNT_FORCE) {
197 					printf(
198 "WARNING: %s was not properly dismounted\n", fs->e2fs_fsmnt);
199 				} else {
200 					printf(
201 "WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
202 					    fs->e2fs_fsmnt);
203 					return (EPERM);
204 				}
205 			}
206 			fs->e2fs->e2fs_state &= ~E2FS_ISCLEAN;
207 			(void)ext2_cgupdate(ump, MNT_WAIT);
208 			fs->e2fs_ronly = 0;
209 			MNT_ILOCK(mp);
210 			mp->mnt_flag &= ~MNT_RDONLY;
211 			MNT_IUNLOCK(mp);
212 		}
213 		if (vfs_flagopt(opts, "export", NULL, 0)) {
214 			/* Process export requests in vfs_mount.c. */
215 			return (error);
216 		}
217 	}
218 
219 	/*
220 	 * Not an update, or updating the name: look up the name
221 	 * and verify that it refers to a sensible disk device.
222 	 */
223 	if (fspec == NULL)
224 		return (EINVAL);
225 	NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspec, td);
226 	if ((error = namei(ndp)) != 0)
227 		return (error);
228 	NDFREE(ndp, NDF_ONLY_PNBUF);
229 	devvp = ndp->ni_vp;
230 
231 	if (!vn_isdisk(devvp, &error)) {
232 		vput(devvp);
233 		return (error);
234 	}
235 
236 	/*
237 	 * If mount by non-root, then verify that user has necessary
238 	 * permissions on the device.
239 	 *
240 	 * XXXRW: VOP_ACCESS() enough?
241 	 */
242 	accmode = VREAD;
243 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
244 		accmode |= VWRITE;
245 	error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
246 	if (error)
247 		error = priv_check(td, PRIV_VFS_MOUNT_PERM);
248 	if (error) {
249 		vput(devvp);
250 		return (error);
251 	}
252 
253 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
254 		error = ext2_mountfs(devvp, mp);
255 	} else {
256 		if (devvp != ump->um_devvp) {
257 			vput(devvp);
258 			return (EINVAL);	/* needs translation */
259 		} else
260 			vput(devvp);
261 	}
262 	if (error) {
263 		vrele(devvp);
264 		return (error);
265 	}
266 	ump = VFSTOEXT2(mp);
267 	fs = ump->um_e2fs;
268 
269 	/*
270 	 * Note that this strncpy() is ok because of a check at the start
271 	 * of ext2_mount().
272 	 */
273 	strncpy(fs->e2fs_fsmnt, path, MAXMNTLEN);
274 	fs->e2fs_fsmnt[MAXMNTLEN - 1] = '\0';
275 	vfs_mountedfrom(mp, fspec);
276 	return (0);
277 }
278 
279 static int
280 ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev, int ronly)
281 {
282 
283 	if (es->e2fs_magic != E2FS_MAGIC) {
284 		printf("ext2fs: %s: wrong magic number %#x (expected %#x)\n",
285 		    devtoname(dev), es->e2fs_magic, E2FS_MAGIC);
286 		return (1);
287 	}
288 	if (es->e2fs_rev > E2FS_REV0) {
289 		if (es->e2fs_features_incompat & ~(EXT2F_INCOMPAT_SUPP |
290 						   EXT4F_RO_INCOMPAT_SUPP)) {
291 			printf(
292 "WARNING: mount of %s denied due to unsupported optional features\n",
293 			    devtoname(dev));
294 			return (1);
295 		}
296 		if (!ronly &&
297 		    (es->e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP)) {
298 			printf("WARNING: R/W mount of %s denied due to "
299 			    "unsupported optional features\n", devtoname(dev));
300 			return (1);
301 		}
302 	}
303 	return (0);
304 }
305 
306 /*
307  * This computes the fields of the m_ext2fs structure from the
308  * data in the ext2fs structure read in.
309  */
310 static int
311 compute_sb_data(struct vnode *devvp, struct ext2fs *es,
312     struct m_ext2fs *fs)
313 {
314 	int db_count, error;
315 	int i;
316 	int logic_sb_block = 1;	/* XXX for now */
317 	struct buf *bp;
318 	uint32_t e2fs_descpb;
319 
320 	fs->e2fs_bshift = EXT2_MIN_BLOCK_LOG_SIZE + es->e2fs_log_bsize;
321 	fs->e2fs_bsize = 1U << fs->e2fs_bshift;
322 	fs->e2fs_fsbtodb = es->e2fs_log_bsize + 1;
323 	fs->e2fs_qbmask = fs->e2fs_bsize - 1;
324 	fs->e2fs_fsize = EXT2_MIN_FRAG_SIZE << es->e2fs_log_fsize;
325 	if (fs->e2fs_fsize)
326 		fs->e2fs_fpb = fs->e2fs_bsize / fs->e2fs_fsize;
327 	fs->e2fs_bpg = es->e2fs_bpg;
328 	fs->e2fs_fpg = es->e2fs_fpg;
329 	fs->e2fs_ipg = es->e2fs_ipg;
330 	if (es->e2fs_rev == E2FS_REV0) {
331 		fs->e2fs_isize = E2FS_REV0_INODE_SIZE ;
332 	} else {
333 		fs->e2fs_isize = es->e2fs_inode_size;
334 
335 		/*
336 		 * Simple sanity check for superblock inode size value.
337 		 */
338 		if (EXT2_INODE_SIZE(fs) < E2FS_REV0_INODE_SIZE ||
339 		    EXT2_INODE_SIZE(fs) > fs->e2fs_bsize ||
340 		    (fs->e2fs_isize & (fs->e2fs_isize - 1)) != 0) {
341 			printf("ext2fs: invalid inode size %d\n",
342 			    fs->e2fs_isize);
343 			return (EIO);
344 		}
345 	}
346 	/* Check for extra isize in big inodes. */
347 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_EXTRA_ISIZE) &&
348 	    EXT2_INODE_SIZE(fs) < sizeof(struct ext2fs_dinode)) {
349 		printf("ext2fs: no space for extra inode timestamps\n");
350 		return (EINVAL);
351 	}
352 
353 	fs->e2fs_ipb = fs->e2fs_bsize / EXT2_INODE_SIZE(fs);
354 	fs->e2fs_itpg = fs->e2fs_ipg / fs->e2fs_ipb;
355 	/* s_resuid / s_resgid ? */
356 	fs->e2fs_gcount = howmany(es->e2fs_bcount - es->e2fs_first_dblock,
357 	    EXT2_BLOCKS_PER_GROUP(fs));
358 	e2fs_descpb = fs->e2fs_bsize / sizeof(struct ext2_gd);
359 	db_count = howmany(fs->e2fs_gcount, e2fs_descpb);
360 	fs->e2fs_gdbcount = db_count;
361 	fs->e2fs_gd = malloc(db_count * fs->e2fs_bsize,
362 	    M_EXT2MNT, M_WAITOK);
363 	fs->e2fs_contigdirs = malloc(fs->e2fs_gcount *
364 	    sizeof(*fs->e2fs_contigdirs), M_EXT2MNT, M_WAITOK | M_ZERO);
365 
366 	/*
367 	 * Adjust logic_sb_block.
368 	 * Godmar thinks: if the blocksize is greater than 1024, then
369 	 * the superblock is logically part of block zero.
370 	 */
371 	if(fs->e2fs_bsize > SBSIZE)
372 		logic_sb_block = 0;
373 	for (i = 0; i < db_count; i++) {
374 		error = bread(devvp ,
375 			 fsbtodb(fs, logic_sb_block + i + 1 ),
376 			fs->e2fs_bsize, NOCRED, &bp);
377 		if (error) {
378 			free(fs->e2fs_contigdirs, M_EXT2MNT);
379 			free(fs->e2fs_gd, M_EXT2MNT);
380 			brelse(bp);
381 			return (error);
382 		}
383 		e2fs_cgload((struct ext2_gd *)bp->b_data,
384 		    &fs->e2fs_gd[
385 			i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
386 		    fs->e2fs_bsize);
387 		brelse(bp);
388 		bp = NULL;
389 	}
390 	/* Initialization for the ext2 Orlov allocator variant. */
391 	fs->e2fs_total_dir = 0;
392 	for (i = 0; i < fs->e2fs_gcount; i++)
393 		fs->e2fs_total_dir += fs->e2fs_gd[i].ext2bgd_ndirs;
394 
395 	if (es->e2fs_rev == E2FS_REV0 ||
396 	    !EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_LARGEFILE))
397 		fs->e2fs_maxfilesize = 0x7fffffff;
398 	else {
399 		fs->e2fs_maxfilesize = 0xffffffffffff;
400 		if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_HUGE_FILE))
401 			fs->e2fs_maxfilesize = 0x7fffffffffffffff;
402 	}
403 	if (es->e4fs_flags & E2FS_UNSIGNED_HASH) {
404 		fs->e2fs_uhash = 3;
405 	} else if ((es->e4fs_flags & E2FS_SIGNED_HASH) == 0) {
406 #ifdef __CHAR_UNSIGNED__
407 		es->e4fs_flags |= E2FS_UNSIGNED_HASH;
408 		fs->e2fs_uhash = 3;
409 #else
410 		es->e4fs_flags |= E2FS_SIGNED_HASH;
411 #endif
412 	}
413 
414 	return (0);
415 }
416 
417 /*
418  * Reload all incore data for a filesystem (used after running fsck on
419  * the root filesystem and finding things to fix). The filesystem must
420  * be mounted read-only.
421  *
422  * Things to do to update the mount:
423  *	1) invalidate all cached meta-data.
424  *	2) re-read superblock from disk.
425  *	3) invalidate all cluster summary information.
426  *	4) invalidate all inactive vnodes.
427  *	5) invalidate all cached file data.
428  *	6) re-read inode data for all active vnodes.
429  * XXX we are missing some steps, in particular # 3, this has to be reviewed.
430  */
431 static int
432 ext2_reload(struct mount *mp, struct thread *td)
433 {
434 	struct vnode *vp, *mvp, *devvp;
435 	struct inode *ip;
436 	struct buf *bp;
437 	struct ext2fs *es;
438 	struct m_ext2fs *fs;
439 	struct csum *sump;
440 	int error, i;
441 	int32_t *lp;
442 
443 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
444 		return (EINVAL);
445 	/*
446 	 * Step 1: invalidate all cached meta-data.
447 	 */
448 	devvp = VFSTOEXT2(mp)->um_devvp;
449 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
450 	if (vinvalbuf(devvp, 0, 0, 0) != 0)
451 		panic("ext2_reload: dirty1");
452 	VOP_UNLOCK(devvp, 0);
453 
454 	/*
455 	 * Step 2: re-read superblock from disk.
456 	 * constants have been adjusted for ext2
457 	 */
458 	if ((error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp)) != 0)
459 		return (error);
460 	es = (struct ext2fs *)bp->b_data;
461 	if (ext2_check_sb_compat(es, devvp->v_rdev, 0) != 0) {
462 		brelse(bp);
463 		return (EIO);		/* XXX needs translation */
464 	}
465 	fs = VFSTOEXT2(mp)->um_e2fs;
466 	bcopy(bp->b_data, fs->e2fs, sizeof(struct ext2fs));
467 
468 	if((error = compute_sb_data(devvp, es, fs)) != 0) {
469 		brelse(bp);
470 		return (error);
471 	}
472 #ifdef UNKLAR
473 	if (fs->fs_sbsize < SBSIZE)
474 		bp->b_flags |= B_INVAL;
475 #endif
476 	brelse(bp);
477 
478 	/*
479 	 * Step 3: invalidate all cluster summary information.
480 	 */
481 	if (fs->e2fs_contigsumsize > 0) {
482 		lp = fs->e2fs_maxcluster;
483 		sump = fs->e2fs_clustersum;
484 		for (i = 0; i < fs->e2fs_gcount; i++, sump++) {
485 			*lp++ = fs->e2fs_contigsumsize;
486 			sump->cs_init = 0;
487 			bzero(sump->cs_sum, fs->e2fs_contigsumsize + 1);
488 		}
489 	}
490 
491 loop:
492 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
493 		/*
494 		 * Step 4: invalidate all cached file data.
495 		 */
496 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
497 			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
498 			goto loop;
499 		}
500 		if (vinvalbuf(vp, 0, 0, 0))
501 			panic("ext2_reload: dirty2");
502 
503 		/*
504 		 * Step 5: re-read inode data for all active vnodes.
505 		 */
506 		ip = VTOI(vp);
507 		error = bread(devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
508 		    (int)fs->e2fs_bsize, NOCRED, &bp);
509 		if (error) {
510 			VOP_UNLOCK(vp, 0);
511 			vrele(vp);
512 			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
513 			return (error);
514 		}
515 		ext2_ei2i((struct ext2fs_dinode *) ((char *)bp->b_data +
516 		    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number)), ip);
517 		brelse(bp);
518 		VOP_UNLOCK(vp, 0);
519 		vrele(vp);
520 	}
521 	return (0);
522 }
523 
524 /*
525  * Common code for mount and mountroot.
526  */
527 static int
528 ext2_mountfs(struct vnode *devvp, struct mount *mp)
529 {
530 	struct ext2mount *ump;
531 	struct buf *bp;
532 	struct m_ext2fs *fs;
533 	struct ext2fs *es;
534 	struct cdev *dev = devvp->v_rdev;
535 	struct g_consumer *cp;
536 	struct bufobj *bo;
537 	struct csum *sump;
538 	int error;
539 	int ronly;
540 	int i, size;
541 	int32_t *lp;
542 	int32_t e2fs_maxcontig;
543 
544 	ronly = vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0);
545 	/* XXX: use VOP_ACESS to check FS perms */
546 	g_topology_lock();
547 	error = g_vfs_open(devvp, &cp, "ext2fs", ronly ? 0 : 1);
548 	g_topology_unlock();
549 	VOP_UNLOCK(devvp, 0);
550 	if (error)
551 		return (error);
552 
553 	/* XXX: should we check for some sectorsize or 512 instead? */
554 	if (((SBSIZE % cp->provider->sectorsize) != 0) ||
555 	    (SBSIZE < cp->provider->sectorsize)) {
556 		g_topology_lock();
557 		g_vfs_close(cp);
558 		g_topology_unlock();
559 		return (EINVAL);
560 	}
561 
562 	bo = &devvp->v_bufobj;
563 	bo->bo_private = cp;
564 	bo->bo_ops = g_vfs_bufops;
565 	if (devvp->v_rdev->si_iosize_max != 0)
566 		mp->mnt_iosize_max = devvp->v_rdev->si_iosize_max;
567 	if (mp->mnt_iosize_max > MAXPHYS)
568 		mp->mnt_iosize_max = MAXPHYS;
569 
570 	bp = NULL;
571 	ump = NULL;
572 	if ((error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp)) != 0)
573 		goto out;
574 	es = (struct ext2fs *)bp->b_data;
575 	if (ext2_check_sb_compat(es, dev, ronly) != 0) {
576 		error = EINVAL;		/* XXX needs translation */
577 		goto out;
578 	}
579 	if ((es->e2fs_state & E2FS_ISCLEAN) == 0 ||
580 	    (es->e2fs_state & E2FS_ERRORS)) {
581 		if (ronly || (mp->mnt_flag & MNT_FORCE)) {
582 			printf(
583 "WARNING: Filesystem was not properly dismounted\n");
584 		} else {
585 			printf(
586 "WARNING: R/W mount denied.  Filesystem is not clean - run fsck\n");
587 			error = EPERM;
588 			goto out;
589 		}
590 	}
591 	ump = malloc(sizeof(*ump), M_EXT2MNT, M_WAITOK | M_ZERO);
592 
593 	/*
594 	 * I don't know whether this is the right strategy. Note that
595 	 * we dynamically allocate both an m_ext2fs and an ext2fs
596 	 * while Linux keeps the super block in a locked buffer.
597 	 */
598 	ump->um_e2fs = malloc(sizeof(struct m_ext2fs),
599 		M_EXT2MNT, M_WAITOK | M_ZERO);
600 	ump->um_e2fs->e2fs = malloc(sizeof(struct ext2fs),
601 		M_EXT2MNT, M_WAITOK);
602 	mtx_init(EXT2_MTX(ump), "EXT2FS", "EXT2FS Lock", MTX_DEF);
603 	bcopy(es, ump->um_e2fs->e2fs, (u_int)sizeof(struct ext2fs));
604 	if ((error = compute_sb_data(devvp, ump->um_e2fs->e2fs, ump->um_e2fs)))
605 		goto out;
606 
607 	/*
608 	 * Calculate the maximum contiguous blocks and size of cluster summary
609 	 * array.  In FFS this is done by newfs; however, the superblock
610 	 * in ext2fs doesn't have these variables, so we can calculate
611 	 * them here.
612 	 */
613 	e2fs_maxcontig = MAX(1, MAXPHYS / ump->um_e2fs->e2fs_bsize);
614 	ump->um_e2fs->e2fs_contigsumsize = MIN(e2fs_maxcontig, EXT2_MAXCONTIG);
615 	if (ump->um_e2fs->e2fs_contigsumsize > 0) {
616 		size = ump->um_e2fs->e2fs_gcount * sizeof(int32_t);
617 		ump->um_e2fs->e2fs_maxcluster = malloc(size, M_EXT2MNT, M_WAITOK);
618 		size = ump->um_e2fs->e2fs_gcount * sizeof(struct csum);
619 		ump->um_e2fs->e2fs_clustersum = malloc(size, M_EXT2MNT, M_WAITOK);
620 		lp = ump->um_e2fs->e2fs_maxcluster;
621 		sump = ump->um_e2fs->e2fs_clustersum;
622 		for (i = 0; i < ump->um_e2fs->e2fs_gcount; i++, sump++) {
623 			*lp++ = ump->um_e2fs->e2fs_contigsumsize;
624 			sump->cs_init = 0;
625 			sump->cs_sum = malloc((ump->um_e2fs->e2fs_contigsumsize + 1) *
626 			    sizeof(int32_t), M_EXT2MNT, M_WAITOK | M_ZERO);
627 		}
628 	}
629 
630 	brelse(bp);
631 	bp = NULL;
632 	fs = ump->um_e2fs;
633 	fs->e2fs_ronly = ronly;	/* ronly is set according to mnt_flags */
634 
635 	/*
636 	 * If the fs is not mounted read-only, make sure the super block is
637 	 * always written back on a sync().
638 	 */
639 	fs->e2fs_wasvalid = fs->e2fs->e2fs_state & E2FS_ISCLEAN ? 1 : 0;
640 	if (ronly == 0) {
641 		fs->e2fs_fmod = 1;		/* mark it modified */
642 		fs->e2fs->e2fs_state &= ~E2FS_ISCLEAN;	/* set fs invalid */
643 	}
644 	mp->mnt_data = ump;
645 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
646 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
647 	mp->mnt_maxsymlinklen = EXT2_MAXSYMLINKLEN;
648 	MNT_ILOCK(mp);
649 	mp->mnt_flag |= MNT_LOCAL;
650 	MNT_IUNLOCK(mp);
651 	ump->um_mountp = mp;
652 	ump->um_dev = dev;
653 	ump->um_devvp = devvp;
654 	ump->um_bo = &devvp->v_bufobj;
655 	ump->um_cp = cp;
656 
657 	/*
658 	 * Setting those two parameters allowed us to use
659 	 * ufs_bmap w/o changse!
660 	 */
661 	ump->um_nindir = EXT2_ADDR_PER_BLOCK(fs);
662 	ump->um_bptrtodb = fs->e2fs->e2fs_log_bsize + 1;
663 	ump->um_seqinc = EXT2_FRAGS_PER_BLOCK(fs);
664 	if (ronly == 0)
665 		ext2_sbupdate(ump, MNT_WAIT);
666 	/*
667 	 * Initialize filesystem stat information in mount struct.
668 	 */
669 	MNT_ILOCK(mp);
670 	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
671 	    MNTK_USES_BCACHE;
672 	MNT_IUNLOCK(mp);
673 	return (0);
674 out:
675 	if (bp)
676 		brelse(bp);
677 	if (cp != NULL) {
678 		g_topology_lock();
679 		g_vfs_close(cp);
680 		g_topology_unlock();
681 	}
682 	if (ump) {
683 		mtx_destroy(EXT2_MTX(ump));
684 		free(ump->um_e2fs->e2fs_gd, M_EXT2MNT);
685 		free(ump->um_e2fs->e2fs_contigdirs, M_EXT2MNT);
686 		free(ump->um_e2fs->e2fs, M_EXT2MNT);
687 		free(ump->um_e2fs, M_EXT2MNT);
688 		free(ump, M_EXT2MNT);
689 		mp->mnt_data = NULL;
690 	}
691 	return (error);
692 }
693 
694 /*
695  * Unmount system call.
696  */
697 static int
698 ext2_unmount(struct mount *mp, int mntflags)
699 {
700 	struct ext2mount *ump;
701 	struct m_ext2fs *fs;
702 	struct csum *sump;
703 	int error, flags, i, ronly;
704 
705 	flags = 0;
706 	if (mntflags & MNT_FORCE) {
707 		if (mp->mnt_flag & MNT_ROOTFS)
708 			return (EINVAL);
709 		flags |= FORCECLOSE;
710 	}
711 	if ((error = ext2_flushfiles(mp, flags, curthread)) != 0)
712 		return (error);
713 	ump = VFSTOEXT2(mp);
714 	fs = ump->um_e2fs;
715 	ronly = fs->e2fs_ronly;
716 	if (ronly == 0 && ext2_cgupdate(ump, MNT_WAIT) == 0) {
717 		if (fs->e2fs_wasvalid)
718 			fs->e2fs->e2fs_state |= E2FS_ISCLEAN;
719 		ext2_sbupdate(ump, MNT_WAIT);
720 	}
721 
722 	g_topology_lock();
723 	g_vfs_close(ump->um_cp);
724 	g_topology_unlock();
725 	vrele(ump->um_devvp);
726 	sump = fs->e2fs_clustersum;
727 	for (i = 0; i < fs->e2fs_gcount; i++, sump++)
728 		free(sump->cs_sum, M_EXT2MNT);
729 	free(fs->e2fs_clustersum, M_EXT2MNT);
730 	free(fs->e2fs_maxcluster, M_EXT2MNT);
731 	free(fs->e2fs_gd, M_EXT2MNT);
732 	free(fs->e2fs_contigdirs, M_EXT2MNT);
733 	free(fs->e2fs, M_EXT2MNT);
734 	free(fs, M_EXT2MNT);
735 	free(ump, M_EXT2MNT);
736 	mp->mnt_data = NULL;
737 	MNT_ILOCK(mp);
738 	mp->mnt_flag &= ~MNT_LOCAL;
739 	MNT_IUNLOCK(mp);
740 	return (error);
741 }
742 
743 /*
744  * Flush out all the files in a filesystem.
745  */
746 static int
747 ext2_flushfiles(struct mount *mp, int flags, struct thread *td)
748 {
749 	int error;
750 
751 	error = vflush(mp, 0, flags, td);
752 	return (error);
753 }
754 /*
755  * Get filesystem statistics.
756  */
757 int
758 ext2_statfs(struct mount *mp, struct statfs *sbp)
759 {
760 	struct ext2mount *ump;
761 	struct m_ext2fs *fs;
762 	uint32_t overhead, overhead_per_group, ngdb;
763 	int i, ngroups;
764 
765 	ump = VFSTOEXT2(mp);
766 	fs = ump->um_e2fs;
767 	if (fs->e2fs->e2fs_magic != E2FS_MAGIC)
768 		panic("ext2_statfs");
769 
770 	/*
771 	 * Compute the overhead (FS structures)
772 	 */
773 	overhead_per_group =
774 	    1 /* block bitmap */ +
775 	    1 /* inode bitmap */ +
776 	    fs->e2fs_itpg;
777 	overhead = fs->e2fs->e2fs_first_dblock +
778 	    fs->e2fs_gcount * overhead_per_group;
779 	if (fs->e2fs->e2fs_rev > E2FS_REV0 &&
780 	    fs->e2fs->e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
781 		for (i = 0, ngroups = 0; i < fs->e2fs_gcount; i++) {
782 			if (cg_has_sb(i))
783 				ngroups++;
784 		}
785 	} else {
786 		ngroups = fs->e2fs_gcount;
787 	}
788 	ngdb = fs->e2fs_gdbcount;
789 	if (fs->e2fs->e2fs_rev > E2FS_REV0 &&
790 	    fs->e2fs->e2fs_features_compat & EXT2F_COMPAT_RESIZE)
791 		ngdb += fs->e2fs->e2fs_reserved_ngdb;
792 	overhead += ngroups * (1 /* superblock */ + ngdb);
793 
794 	sbp->f_bsize = EXT2_FRAG_SIZE(fs);
795 	sbp->f_iosize = EXT2_BLOCK_SIZE(fs);
796 	sbp->f_blocks = fs->e2fs->e2fs_bcount - overhead;
797 	sbp->f_bfree = fs->e2fs->e2fs_fbcount;
798 	sbp->f_bavail = sbp->f_bfree - fs->e2fs->e2fs_rbcount;
799 	sbp->f_files = fs->e2fs->e2fs_icount;
800 	sbp->f_ffree = fs->e2fs->e2fs_ficount;
801 	return (0);
802 }
803 
804 /*
805  * Go through the disk queues to initiate sandbagged IO;
806  * go through the inodes to write those that have been modified;
807  * initiate the writing of the super block if it has been modified.
808  *
809  * Note: we are always called with the filesystem marked `MPBUSY'.
810  */
811 static int
812 ext2_sync(struct mount *mp, int waitfor)
813 {
814 	struct vnode *mvp, *vp;
815 	struct thread *td;
816 	struct inode *ip;
817 	struct ext2mount *ump = VFSTOEXT2(mp);
818 	struct m_ext2fs *fs;
819 	int error, allerror = 0;
820 
821 	td = curthread;
822 	fs = ump->um_e2fs;
823 	if (fs->e2fs_fmod != 0 && fs->e2fs_ronly != 0) {		/* XXX */
824 		printf("fs = %s\n", fs->e2fs_fsmnt);
825 		panic("ext2_sync: rofs mod");
826 	}
827 
828 	/*
829 	 * Write back each (modified) inode.
830 	 */
831 loop:
832 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
833 		if (vp->v_type == VNON) {
834 			VI_UNLOCK(vp);
835 			continue;
836 		}
837 		ip = VTOI(vp);
838 		if ((ip->i_flag &
839 		    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
840 		    (vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
841 		    waitfor == MNT_LAZY)) {
842 			VI_UNLOCK(vp);
843 			continue;
844 		}
845 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
846 		if (error) {
847 			if (error == ENOENT) {
848 				MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
849 				goto loop;
850 			}
851 			continue;
852 		}
853 		if ((error = VOP_FSYNC(vp, waitfor, td)) != 0)
854 			allerror = error;
855 		VOP_UNLOCK(vp, 0);
856 		vrele(vp);
857 	}
858 
859 	/*
860 	 * Force stale filesystem control information to be flushed.
861 	 */
862 	if (waitfor != MNT_LAZY) {
863 		vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
864 		if ((error = VOP_FSYNC(ump->um_devvp, waitfor, td)) != 0)
865 			allerror = error;
866 		VOP_UNLOCK(ump->um_devvp, 0);
867 	}
868 
869 	/*
870 	 * Write back modified superblock.
871 	 */
872 	if (fs->e2fs_fmod != 0) {
873 		fs->e2fs_fmod = 0;
874 		fs->e2fs->e2fs_wtime = time_second;
875 		if ((error = ext2_cgupdate(ump, waitfor)) != 0)
876 			allerror = error;
877 	}
878 	return (allerror);
879 }
880 
881 /*
882  * Look up an EXT2FS dinode number to find its incore vnode, otherwise read it
883  * in from disk.  If it is in core, wait for the lock bit to clear, then
884  * return the inode locked.  Detection and handling of mount points must be
885  * done by the calling routine.
886  */
887 static int
888 ext2_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
889 {
890 	struct m_ext2fs *fs;
891 	struct inode *ip;
892 	struct ext2mount *ump;
893 	struct buf *bp;
894 	struct vnode *vp;
895 	struct thread *td;
896 	int i, error;
897 	int used_blocks;
898 
899 	td = curthread;
900 	error = vfs_hash_get(mp, ino, flags, td, vpp, NULL, NULL);
901 	if (error || *vpp != NULL)
902 		return (error);
903 
904 	ump = VFSTOEXT2(mp);
905 	ip = malloc(sizeof(struct inode), M_EXT2NODE, M_WAITOK | M_ZERO);
906 
907 	/* Allocate a new vnode/inode. */
908 	if ((error = getnewvnode("ext2fs", mp, &ext2_vnodeops, &vp)) != 0) {
909 		*vpp = NULL;
910 		free(ip, M_EXT2NODE);
911 		return (error);
912 	}
913 	vp->v_data = ip;
914 	ip->i_vnode = vp;
915 	ip->i_e2fs = fs = ump->um_e2fs;
916 	ip->i_ump  = ump;
917 	ip->i_number = ino;
918 
919 	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
920 	error = insmntque(vp, mp);
921 	if (error != 0) {
922 		free(ip, M_EXT2NODE);
923 		*vpp = NULL;
924 		return (error);
925 	}
926 	error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
927 	if (error || *vpp != NULL)
928 		return (error);
929 
930 	/* Read in the disk contents for the inode, copy into the inode. */
931 	if ((error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)),
932 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
933 		/*
934 		 * The inode does not contain anything useful, so it would
935 		 * be misleading to leave it on its hash chain. With mode
936 		 * still zero, it will be unlinked and returned to the free
937 		 * list by vput().
938 		 */
939 		brelse(bp);
940 		vput(vp);
941 		*vpp = NULL;
942 		return (error);
943 	}
944 	/* convert ext2 inode to dinode */
945 	ext2_ei2i((struct ext2fs_dinode *) ((char *)bp->b_data + EXT2_INODE_SIZE(fs) *
946 			ino_to_fsbo(fs, ino)), ip);
947 	ip->i_block_group = ino_to_cg(fs, ino);
948 	ip->i_next_alloc_block = 0;
949 	ip->i_next_alloc_goal = 0;
950 
951 	/*
952 	 * Now we want to make sure that block pointers for unused
953 	 * blocks are zeroed out - ext2_balloc depends on this
954 	 * although for regular files and directories only
955 	 *
956 	 * If IN_E4EXTENTS is enabled, unused blocks are not zeroed
957 	 * out because we could corrupt the extent tree.
958 	 */
959 	if (!(ip->i_flag & IN_E4EXTENTS) &&
960 	    (S_ISDIR(ip->i_mode) || S_ISREG(ip->i_mode))) {
961 		used_blocks = howmany(ip->i_size, fs->e2fs_bsize);
962 		for (i = used_blocks; i < EXT2_NDIR_BLOCKS; i++)
963 			ip->i_db[i] = 0;
964 	}
965 #ifdef EXT2FS_DEBUG
966 	ext2_print_inode(ip);
967 #endif
968 	bqrelse(bp);
969 
970 	/*
971 	 * Initialize the vnode from the inode, check for aliases.
972 	 * Note that the underlying vnode may have changed.
973 	 */
974 	if ((error = ext2_vinit(mp, &ext2_fifoops, &vp)) != 0) {
975 		vput(vp);
976 		*vpp = NULL;
977 		return (error);
978 	}
979 
980 	/*
981 	 * Finish inode initialization.
982 	 */
983 
984 	*vpp = vp;
985 	return (0);
986 }
987 
988 /*
989  * File handle to vnode
990  *
991  * Have to be really careful about stale file handles:
992  * - check that the inode number is valid
993  * - call ext2_vget() to get the locked inode
994  * - check for an unallocated inode (i_mode == 0)
995  * - check that the given client host has export rights and return
996  *   those rights via. exflagsp and credanonp
997  */
998 static int
999 ext2_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
1000 {
1001 	struct inode *ip;
1002 	struct ufid *ufhp;
1003 	struct vnode *nvp;
1004 	struct m_ext2fs *fs;
1005 	int error;
1006 
1007 	ufhp = (struct ufid *)fhp;
1008 	fs = VFSTOEXT2(mp)->um_e2fs;
1009 	if (ufhp->ufid_ino < EXT2_ROOTINO ||
1010 	    ufhp->ufid_ino > fs->e2fs_gcount * fs->e2fs->e2fs_ipg)
1011 		return (ESTALE);
1012 
1013 	error = VFS_VGET(mp, ufhp->ufid_ino, LK_EXCLUSIVE, &nvp);
1014 	if (error) {
1015 		*vpp = NULLVP;
1016 		return (error);
1017 	}
1018 	ip = VTOI(nvp);
1019 	if (ip->i_mode == 0 ||
1020 	    ip->i_gen != ufhp->ufid_gen || ip->i_nlink <= 0) {
1021 		vput(nvp);
1022 		*vpp = NULLVP;
1023 		return (ESTALE);
1024 	}
1025 	*vpp = nvp;
1026 	vnode_create_vobject(*vpp, 0, curthread);
1027 	return (0);
1028 }
1029 
1030 /*
1031  * Write a superblock and associated information back to disk.
1032  */
1033 static int
1034 ext2_sbupdate(struct ext2mount *mp, int waitfor)
1035 {
1036 	struct m_ext2fs *fs = mp->um_e2fs;
1037 	struct ext2fs *es = fs->e2fs;
1038 	struct buf *bp;
1039 	int error = 0;
1040 
1041 	bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, 0, 0);
1042 	bcopy((caddr_t)es, bp->b_data, (u_int)sizeof(struct ext2fs));
1043 	if (waitfor == MNT_WAIT)
1044 		error = bwrite(bp);
1045 	else
1046 		bawrite(bp);
1047 
1048 	/*
1049 	 * The buffers for group descriptors, inode bitmaps and block bitmaps
1050 	 * are not busy at this point and are (hopefully) written by the
1051 	 * usual sync mechanism. No need to write them here.
1052 	 */
1053 	return (error);
1054 }
1055 int
1056 ext2_cgupdate(struct ext2mount *mp, int waitfor)
1057 {
1058 	struct m_ext2fs *fs = mp->um_e2fs;
1059 	struct buf *bp;
1060 	int i, error = 0, allerror = 0;
1061 
1062 	allerror = ext2_sbupdate(mp, waitfor);
1063 	for (i = 0; i < fs->e2fs_gdbcount; i++) {
1064 		bp = getblk(mp->um_devvp, fsbtodb(fs,
1065 		    fs->e2fs->e2fs_first_dblock +
1066 		    1 /* superblock */ + i), fs->e2fs_bsize, 0, 0, 0);
1067 		e2fs_cgsave(&fs->e2fs_gd[
1068 		    i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
1069 		    (struct ext2_gd *)bp->b_data, fs->e2fs_bsize);
1070 		if (waitfor == MNT_WAIT)
1071 			error = bwrite(bp);
1072 		else
1073 			bawrite(bp);
1074 	}
1075 
1076 	if (!allerror && error)
1077 		allerror = error;
1078 	return (allerror);
1079 }
1080 /*
1081  * Return the root of a filesystem.
1082  */
1083 static int
1084 ext2_root(struct mount *mp, int flags, struct vnode **vpp)
1085 {
1086 	struct vnode *nvp;
1087 	int error;
1088 
1089 	error = VFS_VGET(mp, EXT2_ROOTINO, LK_EXCLUSIVE, &nvp);
1090 	if (error)
1091 		return (error);
1092 	*vpp = nvp;
1093 	return (0);
1094 }
1095