xref: /netbsd-src/sys/fs/msdosfs/msdosfs_vfsops.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: msdosfs_vfsops.c,v 1.108 2014/05/24 16:34:03 christos Exp $	*/
2 
3 /*-
4  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
5  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
6  * All rights reserved.
7  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by TooLs GmbH.
20  * 4. The name of TooLs GmbH may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
29  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
32  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 /*
35  * Written by Paul Popelka (paulp@uts.amdahl.com)
36  *
37  * You can do anything you want with this software, just don't say you wrote
38  * it, and don't remove this notice.
39  *
40  * This software is provided "as is".
41  *
42  * The author supplies this software to be publicly redistributed on the
43  * understanding that the author is not responsible for the correct
44  * functioning of this software in any circumstances and is not liable for
45  * any damages caused by this software.
46  *
47  * October 1992
48  */
49 
50 #include <sys/cdefs.h>
51 __KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.108 2014/05/24 16:34:03 christos Exp $");
52 
53 #if defined(_KERNEL_OPT)
54 #include "opt_compat_netbsd.h"
55 #endif
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/sysctl.h>
60 #include <sys/namei.h>
61 #include <sys/proc.h>
62 #include <sys/kernel.h>
63 #include <sys/vnode.h>
64 #include <miscfs/genfs/genfs.h>
65 #include <miscfs/specfs/specdev.h> /* XXX */	/* defines v_rdev */
66 #include <sys/mount.h>
67 #include <sys/buf.h>
68 #include <sys/file.h>
69 #include <sys/device.h>
70 #include <sys/disklabel.h>
71 #include <sys/disk.h>
72 #include <sys/fstrans.h>
73 #include <sys/ioctl.h>
74 #include <sys/malloc.h>
75 #include <sys/dirent.h>
76 #include <sys/stat.h>
77 #include <sys/conf.h>
78 #include <sys/kauth.h>
79 #include <sys/module.h>
80 
81 #include <fs/msdosfs/bpb.h>
82 #include <fs/msdosfs/bootsect.h>
83 #include <fs/msdosfs/direntry.h>
84 #include <fs/msdosfs/denode.h>
85 #include <fs/msdosfs/msdosfsmount.h>
86 #include <fs/msdosfs/fat.h>
87 
88 MODULE(MODULE_CLASS_VFS, msdos, NULL);
89 
90 #ifdef MSDOSFS_DEBUG
91 #define DPRINTF(a) uprintf a
92 #else
93 #define DPRINTF(a)
94 #endif
95 
96 #define MSDOSFS_NAMEMAX(pmp) \
97 	(pmp)->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12
98 
99 VFS_PROTOS(msdosfs);
100 
101 int msdosfs_mountfs(struct vnode *, struct mount *, struct lwp *,
102     struct msdosfs_args *);
103 
104 static int update_mp(struct mount *, struct msdosfs_args *);
105 
106 MALLOC_JUSTDEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOS FS mount structure");
107 MALLOC_JUSTDEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOS FS FAT table");
108 MALLOC_JUSTDEFINE(M_MSDOSFSTMP, "MSDOSFS temp", "MSDOS FS temp. structures");
109 
110 #define ROOTNAME "root_device"
111 
112 static struct sysctllog *msdosfs_sysctl_log;
113 
114 extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc;
115 
116 const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = {
117 	&msdosfs_vnodeop_opv_desc,
118 	NULL,
119 };
120 
121 struct vfsops msdosfs_vfsops = {
122 	.vfs_name = MOUNT_MSDOS,
123 	.vfs_min_mount_data = sizeof (struct msdosfs_args),
124 	.vfs_mount = msdosfs_mount,
125 	.vfs_start = msdosfs_start,
126 	.vfs_unmount = msdosfs_unmount,
127 	.vfs_root = msdosfs_root,
128 	.vfs_quotactl = (void *)eopnotsupp,
129 	.vfs_statvfs = msdosfs_statvfs,
130 	.vfs_sync = msdosfs_sync,
131 	.vfs_vget = msdosfs_vget,
132 	.vfs_fhtovp = msdosfs_fhtovp,
133 	.vfs_vptofh = msdosfs_vptofh,
134 	.vfs_init = msdosfs_init,
135 	.vfs_reinit = msdosfs_reinit,
136 	.vfs_done = msdosfs_done,
137 	.vfs_mountroot = msdosfs_mountroot,
138 	.vfs_snapshot = (void *)eopnotsupp,
139 	.vfs_extattrctl = vfs_stdextattrctl,
140 	.vfs_suspendctl = msdosfs_suspendctl,
141 	.vfs_renamelock_enter = genfs_renamelock_enter,
142 	.vfs_renamelock_exit = genfs_renamelock_exit,
143 	.vfs_fsync = (void *)eopnotsupp,
144 	.vfs_opv_descs = msdosfs_vnodeopv_descs
145 };
146 
147 static int
148 msdos_modcmd(modcmd_t cmd, void *arg)
149 {
150 	int error;
151 
152 	switch (cmd) {
153 	case MODULE_CMD_INIT:
154 		error = vfs_attach(&msdosfs_vfsops);
155 		if (error != 0)
156 			break;
157 		sysctl_createv(&msdosfs_sysctl_log, 0, NULL, NULL,
158 			       CTLFLAG_PERMANENT,
159 			       CTLTYPE_NODE, "msdosfs",
160 			       SYSCTL_DESCR("MS-DOS file system"),
161 			       NULL, 0, NULL, 0,
162 			       CTL_VFS, 4, CTL_EOL);
163 		/*
164 		 * XXX the "4" above could be dynamic, thereby eliminating one
165 		 * more instance of the "number to vfs" mapping problem, but
166 		 * "4" is the order as taken from sys/mount.h
167 		 */
168 		break;
169 	case MODULE_CMD_FINI:
170 		error = vfs_detach(&msdosfs_vfsops);
171 		if (error != 0)
172 			break;
173 		sysctl_teardown(&msdosfs_sysctl_log);
174 		break;
175 	default:
176 		error = ENOTTY;
177 		break;
178 	}
179 
180 	return (error);
181 }
182 
183 static int
184 update_mp(struct mount *mp, struct msdosfs_args *argp)
185 {
186 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
187 	int error;
188 
189 	pmp->pm_gid = argp->gid;
190 	pmp->pm_uid = argp->uid;
191 	pmp->pm_mask = argp->mask & ALLPERMS;
192 	pmp->pm_dirmask = argp->dirmask & ALLPERMS;
193 	pmp->pm_gmtoff = argp->gmtoff;
194 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
195 
196 	/*
197 	 * GEMDOS knows nothing about win95 long filenames
198 	 */
199 	if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
200 		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
201 
202 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
203 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
204 	else if (!(pmp->pm_flags &
205 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
206 		struct vnode *rtvp;
207 
208 		/*
209 		 * Try to divine whether to support Win'95 long filenames
210 		 */
211 		if (FAT32(pmp))
212 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
213 		else {
214 			if ((error = msdosfs_root(mp, &rtvp)) != 0)
215 				return error;
216 			pmp->pm_flags |= findwin95(VTODE(rtvp))
217 				? MSDOSFSMNT_LONGNAME
218 					: MSDOSFSMNT_SHORTNAME;
219 			vput(rtvp);
220 		}
221 	}
222 
223 	mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
224 
225 	return 0;
226 }
227 
228 int
229 msdosfs_mountroot(void)
230 {
231 	struct mount *mp;
232 	struct lwp *l = curlwp;	/* XXX */
233 	int error;
234 	struct msdosfs_args args;
235 
236 	if (device_class(root_device) != DV_DISK)
237 		return (ENODEV);
238 
239 	if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) {
240 		vrele(rootvp);
241 		return (error);
242 	}
243 
244 	args.flags = MSDOSFSMNT_VERSIONED;
245 	args.uid = 0;
246 	args.gid = 0;
247 	args.mask = 0777;
248 	args.version = MSDOSFSMNT_VERSION;
249 	args.dirmask = 0777;
250 
251 	if ((error = msdosfs_mountfs(rootvp, mp, l, &args)) != 0) {
252 		vfs_unbusy(mp, false, NULL);
253 		vfs_destroy(mp);
254 		return (error);
255 	}
256 
257 	if ((error = update_mp(mp, &args)) != 0) {
258 		(void)msdosfs_unmount(mp, 0);
259 		vfs_unbusy(mp, false, NULL);
260 		vfs_destroy(mp);
261 		vrele(rootvp);
262 		return (error);
263 	}
264 
265 	mountlist_append(mp);
266 	(void)msdosfs_statvfs(mp, &mp->mnt_stat);
267 	vfs_unbusy(mp, false, NULL);
268 	return (0);
269 }
270 
271 /*
272  * mp - path - addr in user space of mount point (ie /usr or whatever)
273  * data - addr in user space of mount params including the name of the block
274  * special file to treat as a filesystem.
275  */
276 int
277 msdosfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
278 {
279 	struct lwp *l = curlwp;
280 	struct vnode *devvp;	  /* vnode for blk device to mount */
281 	struct msdosfs_args *args = data; /* holds data from mount request */
282 	/* msdosfs specific mount control block */
283 	struct msdosfsmount *pmp = NULL;
284 	int error, flags;
285 	mode_t accessmode;
286 
287 	if (args == NULL)
288 		return EINVAL;
289 	if (*data_len < sizeof *args)
290 		return EINVAL;
291 
292 	if (mp->mnt_flag & MNT_GETARGS) {
293 		pmp = VFSTOMSDOSFS(mp);
294 		if (pmp == NULL)
295 			return EIO;
296 		args->fspec = NULL;
297 		args->uid = pmp->pm_uid;
298 		args->gid = pmp->pm_gid;
299 		args->mask = pmp->pm_mask;
300 		args->flags = pmp->pm_flags;
301 		args->version = MSDOSFSMNT_VERSION;
302 		args->dirmask = pmp->pm_dirmask;
303 		args->gmtoff = pmp->pm_gmtoff;
304 		*data_len = sizeof *args;
305 		return 0;
306 	}
307 
308 	/*
309 	 * If not versioned (i.e. using old mount_msdos(8)), fill in
310 	 * the additional structure items with suitable defaults.
311 	 */
312 	if ((args->flags & MSDOSFSMNT_VERSIONED) == 0) {
313 		args->version = 1;
314 		args->dirmask = args->mask;
315 	}
316 
317 	/*
318 	 * Reset GMT offset for pre-v3 mount structure args.
319 	 */
320 	if (args->version < 3)
321 		args->gmtoff = 0;
322 
323 	/*
324 	 * If updating, check whether changing from read-only to
325 	 * read/write; if there is no device name, that's all we do.
326 	 */
327 	if (mp->mnt_flag & MNT_UPDATE) {
328 		pmp = VFSTOMSDOSFS(mp);
329 		error = 0;
330 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
331 		    (mp->mnt_flag & MNT_RDONLY)) {
332 			flags = WRITECLOSE;
333 			if (mp->mnt_flag & MNT_FORCE)
334 				flags |= FORCECLOSE;
335 			error = vflush(mp, NULLVP, flags);
336 		}
337 		if (!error && (mp->mnt_flag & MNT_RELOAD))
338 			/* not yet implemented */
339 			error = EOPNOTSUPP;
340 		if (error) {
341 			DPRINTF(("vflush %d\n", error));
342 			return (error);
343 		}
344 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
345 		    (mp->mnt_iflag & IMNT_WANTRDWR)) {
346 			/*
347 			 * If upgrade to read-write by non-root, then verify
348 			 * that user has necessary permissions on the device.
349 			 *
350 			 * Permission to update a mount is checked higher, so
351 			 * here we presume updating the mount is okay (for
352 			 * example, as far as securelevel goes) which leaves us
353 			 * with the normal check.
354 			 */
355 			devvp = pmp->pm_devvp;
356 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
357 			error = kauth_authorize_system(l->l_cred,
358 			    KAUTH_SYSTEM_MOUNT, KAUTH_REQ_SYSTEM_MOUNT_DEVICE,
359 			    mp, devvp, KAUTH_ARG(VREAD | VWRITE));
360 			VOP_UNLOCK(devvp);
361 			DPRINTF(("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d\n", error));
362 			if (error)
363 				return (error);
364 
365 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
366 		}
367 		if (args->fspec == NULL) {
368 			DPRINTF(("missing fspec\n"));
369 			return EINVAL;
370 		}
371 	}
372 	/*
373 	 * Not an update, or updating the name: look up the name
374 	 * and verify that it refers to a sensible block device.
375 	 */
376 	error = namei_simple_user(args->fspec,
377 				NSM_FOLLOW_NOEMULROOT, &devvp);
378 	if (error != 0) {
379 		DPRINTF(("namei %d\n", error));
380 		return (error);
381 	}
382 
383 	if (devvp->v_type != VBLK) {
384 		DPRINTF(("not block\n"));
385 		vrele(devvp);
386 		return (ENOTBLK);
387 	}
388 	if (bdevsw_lookup(devvp->v_rdev) == NULL) {
389 		DPRINTF(("no block switch\n"));
390 		vrele(devvp);
391 		return (ENXIO);
392 	}
393 	/*
394 	 * If mount by non-root, then verify that user has necessary
395 	 * permissions on the device.
396 	 */
397 	accessmode = VREAD;
398 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
399 		accessmode |= VWRITE;
400 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
401 	error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
402 	    KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(accessmode));
403 	VOP_UNLOCK(devvp);
404 	if (error) {
405 		DPRINTF(("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d\n", error));
406 		vrele(devvp);
407 		return (error);
408 	}
409 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
410 		int xflags;
411 
412 		if (mp->mnt_flag & MNT_RDONLY)
413 			xflags = FREAD;
414 		else
415 			xflags = FREAD|FWRITE;
416 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
417 		error = VOP_OPEN(devvp, xflags, FSCRED);
418 		VOP_UNLOCK(devvp);
419 		if (error) {
420 			DPRINTF(("VOP_OPEN %d\n", error));
421 			goto fail;
422 		}
423 		error = msdosfs_mountfs(devvp, mp, l, args);
424 		if (error) {
425 			DPRINTF(("msdosfs_mountfs %d\n", error));
426 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
427 			(void) VOP_CLOSE(devvp, xflags, NOCRED);
428 			VOP_UNLOCK(devvp);
429 			goto fail;
430 		}
431 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
432 		pmp = VFSTOMSDOSFS(mp);
433 #endif
434 	} else {
435 		vrele(devvp);
436 		if (devvp != pmp->pm_devvp) {
437 			DPRINTF(("devvp %p pmp %p\n",
438 			    devvp, pmp->pm_devvp));
439 			return (EINVAL);	/* needs translation */
440 		}
441 	}
442 	if ((error = update_mp(mp, args)) != 0) {
443 		msdosfs_unmount(mp, MNT_FORCE);
444 		DPRINTF(("update_mp %d\n", error));
445 		return error;
446 	}
447 
448 #ifdef MSDOSFS_DEBUG
449 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
450 #endif
451 	return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
452 	    mp->mnt_op->vfs_name, mp, l);
453 
454 fail:
455 	vrele(devvp);
456 	return (error);
457 }
458 
459 int
460 msdosfs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l, struct msdosfs_args *argp)
461 {
462 	struct msdosfsmount *pmp;
463 	struct buf *bp;
464 	dev_t dev = devvp->v_rdev;
465 	union bootsector *bsp;
466 	struct byte_bpb33 *b33;
467 	struct byte_bpb50 *b50;
468 	struct byte_bpb710 *b710;
469 	uint8_t SecPerClust;
470 	int	ronly, error, tmp;
471 	int	bsize;
472 	uint64_t psize;
473 	unsigned secsize;
474 
475 	/* Flush out any old buffers remaining from a previous use. */
476 	if ((error = vinvalbuf(devvp, V_SAVE, l->l_cred, l, 0, 0)) != 0)
477 		return (error);
478 
479 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
480 
481 	bp  = NULL; /* both used in error_exit */
482 	pmp = NULL;
483 
484 	error = fstrans_mount(mp);
485 	if (error)
486 		goto error_exit;
487 
488 	error = getdisksize(devvp, &psize, &secsize);
489 	if (error) {
490 		if (argp->flags & MSDOSFSMNT_GEMDOSFS)
491 			goto error_exit;
492 
493 		/* ok, so it failed.  we most likely don't need the info */
494 		secsize = DEV_BSIZE;
495 		psize = 0;
496 		error = 0;
497 	}
498 
499 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
500 		bsize = secsize;
501 		if (bsize != 512) {
502 			DPRINTF(("Invalid block bsize %d for GEMDOS\n", bsize));
503 			error = EINVAL;
504 			goto error_exit;
505 		}
506 	} else
507 		bsize = 0;
508 
509 	/*
510 	 * Read the boot sector of the filesystem, and then check the
511 	 * boot signature.  If not a dos boot sector then error out.
512 	 */
513 	if ((error = bread(devvp, 0, secsize, NOCRED, 0, &bp)) != 0)
514 		goto error_exit;
515 	bsp = (union bootsector *)bp->b_data;
516 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
517 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
518 	b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
519 
520 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
521 		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
522 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
523 			DPRINTF(("bootsig0 %d bootsig1 %d\n",
524 			    bsp->bs50.bsBootSectSig0,
525 			    bsp->bs50.bsBootSectSig1));
526 			error = EINVAL;
527 			goto error_exit;
528 		}
529 	}
530 
531 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
532 	memset(pmp, 0, sizeof *pmp);
533 	pmp->pm_mountp = mp;
534 
535 	/*
536 	 * Compute several useful quantities from the bpb in the
537 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
538 	 * the fields that are different between dos 5 and dos 3.3.
539 	 */
540 	SecPerClust = b50->bpbSecPerClust;
541 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
542 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
543 	pmp->pm_FATs = b50->bpbFATs;
544 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
545 	pmp->pm_Sectors = getushort(b50->bpbSectors);
546 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
547 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
548 	pmp->pm_Heads = getushort(b50->bpbHeads);
549 	pmp->pm_Media = b50->bpbMedia;
550 
551 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
552 		/* XXX - We should probably check more values here */
553     		if (!pmp->pm_BytesPerSec || !SecPerClust
554 	    		|| pmp->pm_SecPerTrack > 63) {
555 			DPRINTF(("bytespersec %d secperclust %d "
556 			    "secpertrack %d\n",
557 			    pmp->pm_BytesPerSec, SecPerClust,
558 			    pmp->pm_SecPerTrack));
559 			error = EINVAL;
560 			goto error_exit;
561 		}
562 	}
563 
564 	if (pmp->pm_Sectors == 0) {
565 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
566 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
567 	} else {
568 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
569 		pmp->pm_HugeSectors = pmp->pm_Sectors;
570 	}
571 
572 	if (pmp->pm_RootDirEnts == 0) {
573 		unsigned short vers = getushort(b710->bpbFSVers);
574 		/*
575 		 * Some say that bsBootSectSig[23] must be zero, but
576 		 * Windows does not require this and some digital cameras
577 		 * do not set these to zero.  Therefore, do not insist.
578 		 */
579 		if (pmp->pm_Sectors || pmp->pm_FATsecs || vers) {
580 			DPRINTF(("sectors %d fatsecs %lu vers %d\n",
581 			    pmp->pm_Sectors, pmp->pm_FATsecs, vers));
582 			error = EINVAL;
583 			goto error_exit;
584 		}
585 		pmp->pm_fatmask = FAT32_MASK;
586 		pmp->pm_fatmult = 4;
587 		pmp->pm_fatdiv = 1;
588 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
589 
590 		/* mirrorring is enabled if the FATMIRROR bit is not set */
591 		if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0)
592 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
593 		else
594 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
595 	} else
596 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
597 
598 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
599 		if (FAT32(pmp)) {
600 			DPRINTF(("FAT32 for GEMDOS\n"));
601 			/*
602 			 * GEMDOS doesn't know FAT32.
603 			 */
604 			error = EINVAL;
605 			goto error_exit;
606 		}
607 
608 		/*
609 		 * Check a few values (could do some more):
610 		 * - logical sector size: power of 2, >= block size
611 		 * - sectors per cluster: power of 2, >= 1
612 		 * - number of sectors:   >= 1, <= size of partition
613 		 */
614 		if ( (SecPerClust == 0)
615 		  || (SecPerClust & (SecPerClust - 1))
616 		  || (pmp->pm_BytesPerSec < bsize)
617 		  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
618 		  || (pmp->pm_HugeSectors == 0)
619 		  || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
620 		      > psize)) {
621 			DPRINTF(("consistency checks for GEMDOS\n"));
622 			error = EINVAL;
623 			goto error_exit;
624 		}
625 		/*
626 		 * XXX - Many parts of the msdosfs driver seem to assume that
627 		 * the number of bytes per logical sector (BytesPerSec) will
628 		 * always be the same as the number of bytes per disk block
629 		 * Let's pretend it is.
630 		 */
631 		tmp = pmp->pm_BytesPerSec / bsize;
632 		pmp->pm_BytesPerSec  = bsize;
633 		pmp->pm_HugeSectors *= tmp;
634 		pmp->pm_HiddenSects *= tmp;
635 		pmp->pm_ResSectors  *= tmp;
636 		pmp->pm_Sectors     *= tmp;
637 		pmp->pm_FATsecs     *= tmp;
638 		SecPerClust         *= tmp;
639 	}
640 
641 	/* Check that fs has nonzero FAT size */
642 	if (pmp->pm_FATsecs == 0) {
643 		DPRINTF(("FATsecs is 0\n"));
644 		error = EINVAL;
645 		goto error_exit;
646 	}
647 
648 	pmp->pm_fatblk = pmp->pm_ResSectors;
649 	if (FAT32(pmp)) {
650 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
651 		pmp->pm_firstcluster = pmp->pm_fatblk
652 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
653 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
654 	} else {
655 		pmp->pm_rootdirblk = pmp->pm_fatblk +
656 			(pmp->pm_FATs * pmp->pm_FATsecs);
657 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
658 				       + pmp->pm_BytesPerSec - 1)
659 			/ pmp->pm_BytesPerSec;/* in sectors */
660 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
661 	}
662 
663 	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
664 	    SecPerClust;
665 	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
666 	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
667 
668 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
669 		if (pmp->pm_nmbrofclusters <= (0xff0 - 2)) {
670 			pmp->pm_fatmask = FAT12_MASK;
671 			pmp->pm_fatmult = 3;
672 			pmp->pm_fatdiv = 2;
673 		} else {
674 			pmp->pm_fatmask = FAT16_MASK;
675 			pmp->pm_fatmult = 2;
676 			pmp->pm_fatdiv = 1;
677 		}
678 	} else if (pmp->pm_fatmask == 0) {
679 		if (pmp->pm_maxcluster
680 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
681 			/*
682 			 * This will usually be a floppy disk. This size makes
683 			 * sure that one FAT entry will not be split across
684 			 * multiple blocks.
685 			 */
686 			pmp->pm_fatmask = FAT12_MASK;
687 			pmp->pm_fatmult = 3;
688 			pmp->pm_fatdiv = 2;
689 		} else {
690 			pmp->pm_fatmask = FAT16_MASK;
691 			pmp->pm_fatmult = 2;
692 			pmp->pm_fatdiv = 1;
693 		}
694 	}
695 	if (FAT12(pmp))
696 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
697 	else
698 		pmp->pm_fatblocksize = MAXBSIZE;
699 
700 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
701 	pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
702 
703 	/*
704 	 * Compute mask and shift value for isolating cluster relative byte
705 	 * offsets and cluster numbers from a file offset.
706 	 */
707 	pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
708 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
709 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
710 
711 	/*
712 	 * Check for valid cluster size
713 	 * must be a power of 2
714 	 */
715 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
716 		DPRINTF(("bpcluster %lu cnshift %lu\n",
717 		    pmp->pm_bpcluster, pmp->pm_cnshift));
718 		error = EINVAL;
719 		goto error_exit;
720 	}
721 
722 	/*
723 	 * Cluster size must be within limit of MAXBSIZE.
724 	 * Many FAT filesystems will not have clusters larger than
725 	 * 32KiB due to limits in Windows versions before Vista.
726 	 */
727 	if (pmp->pm_bpcluster > MAXBSIZE) {
728 		DPRINTF(("bpcluster %lu > MAXBSIZE %d\n",
729 		    pmp->pm_bpcluster, MAXBSIZE));
730 		error = EINVAL;
731 		goto error_exit;
732 	}
733 
734 	/*
735 	 * Release the bootsector buffer.
736 	 */
737 	brelse(bp, BC_AGE);
738 	bp = NULL;
739 
740 	/*
741 	 * Check FSInfo.
742 	 */
743 	if (pmp->pm_fsinfo) {
744 		struct fsinfo *fp;
745 
746 		/*
747 		 * XXX	If the fsinfo block is stored on media with
748 		 *	2KB or larger sectors, is the fsinfo structure
749 		 *	padded at the end or in the middle?
750 		 */
751 		if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo),
752 		    pmp->pm_BytesPerSec, NOCRED, 0, &bp)) != 0)
753 			goto error_exit;
754 		fp = (struct fsinfo *)bp->b_data;
755 		if (!memcmp(fp->fsisig1, "RRaA", 4)
756 		    && !memcmp(fp->fsisig2, "rrAa", 4)
757 		    && !memcmp(fp->fsisig3, "\0\0\125\252", 4)
758 		    && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
759 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
760 		else
761 			pmp->pm_fsinfo = 0;
762 		brelse(bp, 0);
763 		bp = NULL;
764 	}
765 
766 	/*
767 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
768 	 * XXX
769 	 */
770 	if (pmp->pm_fsinfo) {
771 		if ((pmp->pm_nxtfree == 0xffffffffUL) ||
772 		    (pmp->pm_nxtfree > pmp->pm_maxcluster))
773 			pmp->pm_fsinfo = 0;
774 	}
775 
776 	/*
777 	 * Allocate memory for the bitmap of allocated clusters, and then
778 	 * fill it in.
779 	 */
780 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS)
781 				   / N_INUSEBITS)
782 				  * sizeof(*pmp->pm_inusemap),
783 				  M_MSDOSFSFAT, M_WAITOK);
784 
785 	/*
786 	 * fillinusemap() needs pm_devvp.
787 	 */
788 	pmp->pm_dev = dev;
789 	pmp->pm_devvp = devvp;
790 
791 	/*
792 	 * Have the inuse map filled in.
793 	 */
794 	if ((error = fillinusemap(pmp)) != 0) {
795 		DPRINTF(("fillinusemap %d\n", error));
796 		goto error_exit;
797 	}
798 
799 	/*
800 	 * If they want FAT updates to be synchronous then let them suffer
801 	 * the performance degradation in exchange for the on disk copy of
802 	 * the FAT being correct just about all the time.  I suppose this
803 	 * would be a good thing to turn on if the kernel is still flakey.
804 	 */
805 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
806 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
807 
808 	/*
809 	 * Finish up.
810 	 */
811 	if (ronly)
812 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
813 	else
814 		pmp->pm_fmod = 1;
815 	mp->mnt_data = pmp;
816 	mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
817 	mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_MSDOS);
818 	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
819 	mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
820 	mp->mnt_flag |= MNT_LOCAL;
821 	mp->mnt_dev_bshift = pmp->pm_bnshift;
822 	mp->mnt_fs_bshift = pmp->pm_cnshift;
823 
824 	/*
825 	 * If we ever do quotas for DOS filesystems this would be a place
826 	 * to fill in the info in the msdosfsmount structure. You dolt,
827 	 * quotas on dos filesystems make no sense because files have no
828 	 * owners on dos filesystems. of course there is some empty space
829 	 * in the directory entry where we could put uid's and gid's.
830 	 */
831 
832 	spec_node_setmountedfs(devvp, mp);
833 
834 	return (0);
835 
836 error_exit:
837 	fstrans_unmount(mp);
838 	if (bp)
839 		brelse(bp, BC_AGE);
840 	if (pmp) {
841 		if (pmp->pm_inusemap)
842 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
843 		free(pmp, M_MSDOSFSMNT);
844 		mp->mnt_data = NULL;
845 	}
846 	return (error);
847 }
848 
849 int
850 msdosfs_start(struct mount *mp, int flags)
851 {
852 
853 	return (0);
854 }
855 
856 /*
857  * Unmount the filesystem described by mp.
858  */
859 int
860 msdosfs_unmount(struct mount *mp, int mntflags)
861 {
862 	struct msdosfsmount *pmp;
863 	int error, flags;
864 
865 	flags = 0;
866 	if (mntflags & MNT_FORCE)
867 		flags |= FORCECLOSE;
868 	if ((error = vflush(mp, NULLVP, flags)) != 0)
869 		return (error);
870 	pmp = VFSTOMSDOSFS(mp);
871 	if (pmp->pm_devvp->v_type != VBAD)
872 		spec_node_setmountedfs(pmp->pm_devvp, NULL);
873 #ifdef MSDOSFS_DEBUG
874 	{
875 		struct vnode *vp = pmp->pm_devvp;
876 
877 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
878 		printf("flag %08x, usecount %d, writecount %d, holdcnt %d\n",
879 		    vp->v_vflag | vp->v_iflag | vp->v_uflag, vp->v_usecount,
880 		    vp->v_writecount, vp->v_holdcnt);
881 		printf("mount %p, op %p\n",
882 		    vp->v_mount, vp->v_op);
883 		printf("freef %p, freeb %p, mount %p\n",
884 		    vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
885 		    vp->v_mount);
886 		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
887 		    vp->v_cleanblkhd.lh_first,
888 		    vp->v_dirtyblkhd.lh_first,
889 		    vp->v_numoutput, vp->v_type);
890 		printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
891 		    vp->v_socket, vp->v_tag,
892 		    ((u_int *)vp->v_data)[0],
893 		    ((u_int *)vp->v_data)[1]);
894 	}
895 #endif
896 	vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
897 	(void) VOP_CLOSE(pmp->pm_devvp,
898 	    pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED);
899 	vput(pmp->pm_devvp);
900 	msdosfs_fh_destroy(pmp);
901 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
902 	free(pmp, M_MSDOSFSMNT);
903 	mp->mnt_data = NULL;
904 	mp->mnt_flag &= ~MNT_LOCAL;
905 	fstrans_unmount(mp);
906 	return (0);
907 }
908 
909 int
910 msdosfs_root(struct mount *mp, struct vnode **vpp)
911 {
912 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
913 	struct denode *ndep;
914 	int error;
915 
916 #ifdef MSDOSFS_DEBUG
917 	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
918 #endif
919 	if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0)
920 		return (error);
921 	*vpp = DETOV(ndep);
922 	return (0);
923 }
924 
925 int
926 msdosfs_statvfs(struct mount *mp, struct statvfs *sbp)
927 {
928 	struct msdosfsmount *pmp;
929 
930 	pmp = VFSTOMSDOSFS(mp);
931 	sbp->f_bsize = pmp->pm_bpcluster;
932 	sbp->f_frsize = sbp->f_bsize;
933 	sbp->f_iosize = pmp->pm_bpcluster;
934 	sbp->f_blocks = pmp->pm_nmbrofclusters;
935 	sbp->f_bfree = pmp->pm_freeclustercount;
936 	sbp->f_bavail = pmp->pm_freeclustercount;
937 	sbp->f_bresvd = 0;
938 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
939 	sbp->f_ffree = 0;	/* what to put in here? */
940 	sbp->f_favail = 0;	/* what to put in here? */
941 	sbp->f_fresvd = 0;
942 	copy_statvfs_info(sbp, mp);
943 	return (0);
944 }
945 
946 struct msdosfs_sync_ctx {
947 	int waitfor;
948 };
949 
950 static bool
951 msdosfs_sync_selector(void *cl, struct vnode *vp)
952 {
953 	struct msdosfs_sync_ctx *c = cl;
954 	struct denode *dep;
955 
956 	dep = VTODE(vp);
957 	if (c->waitfor == MNT_LAZY || vp->v_type == VNON ||
958 	    dep == NULL || (((dep->de_flag &
959 	    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
960 	     (LIST_EMPTY(&vp->v_dirtyblkhd) &&
961 	      UVM_OBJ_IS_CLEAN(&vp->v_uobj))))
962 		return false;
963 	return true;
964 }
965 
966 int
967 msdosfs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
968 {
969 	struct vnode *vp;
970 	struct vnode_iterator *marker;
971 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
972 	int error, allerror = 0;
973 	struct msdosfs_sync_ctx ctx;
974 
975 	/*
976 	 * If we ever switch to not updating all of the FATs all the time,
977 	 * this would be the place to update them from the first one.
978 	 */
979 	if (pmp->pm_fmod != 0) {
980 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
981 			panic("msdosfs_sync: rofs mod");
982 		else {
983 			/* update FATs here */
984 		}
985 	}
986 	fstrans_start(mp, FSTRANS_SHARED);
987 	/*
988 	 * Write back each (modified) denode.
989 	 */
990 	vfs_vnode_iterator_init(mp, &marker);
991 	ctx.waitfor = waitfor;
992 	while ((vp = vfs_vnode_iterator_next(marker, msdosfs_sync_selector,
993 	    &ctx)))
994 	{
995 		error = vn_lock(vp, LK_EXCLUSIVE);
996 		if (error) {
997 			vrele(vp);
998 			continue;
999 		}
1000 		if ((error = VOP_FSYNC(vp, cred,
1001 		    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
1002 			allerror = error;
1003 		vput(vp);
1004 	}
1005 	vfs_vnode_iterator_destroy(marker);
1006 
1007 	/*
1008 	 * Force stale file system control information to be flushed.
1009 	 */
1010 	if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
1011 	    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
1012 		allerror = error;
1013 	fstrans_done(mp);
1014 	return (allerror);
1015 }
1016 
1017 int
1018 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
1019 {
1020 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
1021 	struct defid defh;
1022 	struct denode *dep;
1023 	uint32_t gen;
1024 	int error;
1025 
1026 	if (fhp->fid_len != sizeof(struct defid)) {
1027 		DPRINTF(("fid_len %d %zd\n", fhp->fid_len,
1028 		    sizeof(struct defid)));
1029 		return EINVAL;
1030 	}
1031 	memcpy(&defh, fhp, sizeof(defh));
1032 	error = msdosfs_fh_lookup(pmp, defh.defid_dirclust, defh.defid_dirofs,
1033 	    &gen);
1034 	if (error == 0 && gen != defh.defid_gen)
1035 		error = ESTALE;
1036 	if (error) {
1037 		*vpp = NULLVP;
1038 		return error;
1039 	}
1040 	error = deget(pmp, defh.defid_dirclust, defh.defid_dirofs, &dep);
1041 	if (error) {
1042 		DPRINTF(("deget %d\n", error));
1043 		*vpp = NULLVP;
1044 		return (error);
1045 	}
1046 	*vpp = DETOV(dep);
1047 	return (0);
1048 }
1049 
1050 int
1051 msdosfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
1052 {
1053 	struct msdosfsmount *pmp = VFSTOMSDOSFS(vp->v_mount);
1054 	struct denode *dep;
1055 	struct defid defh;
1056 	int error;
1057 
1058 	if (*fh_size < sizeof(struct defid)) {
1059 		*fh_size = sizeof(struct defid);
1060 		return E2BIG;
1061 	}
1062 	*fh_size = sizeof(struct defid);
1063 	dep = VTODE(vp);
1064 	memset(&defh, 0, sizeof(defh));
1065 	defh.defid_len = sizeof(struct defid);
1066 	defh.defid_dirclust = dep->de_dirclust;
1067 	defh.defid_dirofs = dep->de_diroffset;
1068 	error = msdosfs_fh_enter(pmp, dep->de_dirclust, dep->de_diroffset,
1069 	     &defh.defid_gen);
1070 	if (error == 0)
1071 		memcpy(fhp, &defh, sizeof(defh));
1072 	return error;
1073 }
1074 
1075 int
1076 msdosfs_vget(struct mount *mp, ino_t ino,
1077     struct vnode **vpp)
1078 {
1079 
1080 	return (EOPNOTSUPP);
1081 }
1082 
1083 int
1084 msdosfs_suspendctl(struct mount *mp, int cmd)
1085 {
1086 	int error;
1087 	struct lwp *l = curlwp;
1088 
1089 	switch (cmd) {
1090 	case SUSPEND_SUSPEND:
1091 		if ((error = fstrans_setstate(mp, FSTRANS_SUSPENDING)) != 0)
1092 			return error;
1093 		error = msdosfs_sync(mp, MNT_WAIT, l->l_proc->p_cred);
1094 		if (error == 0)
1095 			error = fstrans_setstate(mp, FSTRANS_SUSPENDED);
1096 		if (error != 0) {
1097 			(void) fstrans_setstate(mp, FSTRANS_NORMAL);
1098 			return error;
1099 		}
1100 		return 0;
1101 
1102 	case SUSPEND_RESUME:
1103 		return fstrans_setstate(mp, FSTRANS_NORMAL);
1104 
1105 	default:
1106 		return EINVAL;
1107 	}
1108 }
1109