1 /* $NetBSD: msdosfs_vfsops.c,v 1.118 2015/03/28 19:24:05 maxv 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 1.118 2015/03/28 19:24:05 maxv 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(fmt, ...) uprintf("%s(): " fmt "\n", __func__, ##__VA_ARGS__)
92 #else
93 #define DPRINTF(fmt, ...)
94 #endif
95
96 #define GEMDOSFS_BSIZE 512
97
98 #define MSDOSFS_NAMEMAX(pmp) \
99 (pmp)->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12
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 static struct sysctllog *msdosfs_sysctl_log;
111
112 extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc;
113
114 const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = {
115 &msdosfs_vnodeop_opv_desc,
116 NULL,
117 };
118
119 struct vfsops msdosfs_vfsops = {
120 .vfs_name = MOUNT_MSDOS,
121 .vfs_min_mount_data = sizeof (struct msdosfs_args),
122 .vfs_mount = msdosfs_mount,
123 .vfs_start = msdosfs_start,
124 .vfs_unmount = msdosfs_unmount,
125 .vfs_root = msdosfs_root,
126 .vfs_quotactl = (void *)eopnotsupp,
127 .vfs_statvfs = msdosfs_statvfs,
128 .vfs_sync = msdosfs_sync,
129 .vfs_vget = msdosfs_vget,
130 .vfs_loadvnode = msdosfs_loadvnode,
131 .vfs_fhtovp = msdosfs_fhtovp,
132 .vfs_vptofh = msdosfs_vptofh,
133 .vfs_init = msdosfs_init,
134 .vfs_reinit = msdosfs_reinit,
135 .vfs_done = msdosfs_done,
136 .vfs_mountroot = msdosfs_mountroot,
137 .vfs_snapshot = (void *)eopnotsupp,
138 .vfs_extattrctl = vfs_stdextattrctl,
139 .vfs_suspendctl = msdosfs_suspendctl,
140 .vfs_renamelock_enter = genfs_renamelock_enter,
141 .vfs_renamelock_exit = genfs_renamelock_exit,
142 .vfs_fsync = (void *)eopnotsupp,
143 .vfs_opv_descs = msdosfs_vnodeopv_descs
144 };
145
146 static int
msdos_modcmd(modcmd_t cmd,void * arg)147 msdos_modcmd(modcmd_t cmd, void *arg)
148 {
149 int error;
150
151 switch (cmd) {
152 case MODULE_CMD_INIT:
153 error = vfs_attach(&msdosfs_vfsops);
154 if (error != 0)
155 break;
156 sysctl_createv(&msdosfs_sysctl_log, 0, NULL, NULL,
157 CTLFLAG_PERMANENT,
158 CTLTYPE_NODE, "msdosfs",
159 SYSCTL_DESCR("MS-DOS file system"),
160 NULL, 0, NULL, 0,
161 CTL_VFS, 4, CTL_EOL);
162 /*
163 * XXX the "4" above could be dynamic, thereby eliminating one
164 * more instance of the "number to vfs" mapping problem, but
165 * "4" is the order as taken from sys/mount.h
166 */
167 break;
168 case MODULE_CMD_FINI:
169 error = vfs_detach(&msdosfs_vfsops);
170 if (error != 0)
171 break;
172 sysctl_teardown(&msdosfs_sysctl_log);
173 break;
174 default:
175 error = ENOTTY;
176 break;
177 }
178
179 return (error);
180 }
181
182 static int
update_mp(struct mount * mp,struct msdosfs_args * argp)183 update_mp(struct mount *mp, struct msdosfs_args *argp)
184 {
185 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
186 int error;
187
188 pmp->pm_gid = argp->gid;
189 pmp->pm_uid = argp->uid;
190 pmp->pm_mask = argp->mask & ALLPERMS;
191 pmp->pm_dirmask = argp->dirmask & ALLPERMS;
192 pmp->pm_gmtoff = argp->gmtoff;
193 pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
194
195 /*
196 * GEMDOS knows nothing about win95 long filenames
197 */
198 if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
199 pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
200
201 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
202 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
203 else if (!(pmp->pm_flags &
204 (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
205 struct vnode *rtvp;
206
207 /*
208 * Try to divine whether to support Win'95 long filenames
209 */
210 if (FAT32(pmp))
211 pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
212 else {
213 if ((error = msdosfs_root(mp, &rtvp)) != 0)
214 return error;
215 pmp->pm_flags |= findwin95(VTODE(rtvp))
216 ? MSDOSFSMNT_LONGNAME
217 : MSDOSFSMNT_SHORTNAME;
218 vput(rtvp);
219 }
220 }
221
222 mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
223
224 return 0;
225 }
226
227 int
msdosfs_mountroot(void)228 msdosfs_mountroot(void)
229 {
230 struct mount *mp;
231 struct lwp *l = curlwp; /* XXX */
232 int error;
233 struct msdosfs_args args;
234
235 if (device_class(root_device) != DV_DISK)
236 return (ENODEV);
237
238 if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) {
239 vrele(rootvp);
240 return (error);
241 }
242
243 args.flags = MSDOSFSMNT_VERSIONED;
244 args.uid = 0;
245 args.gid = 0;
246 args.mask = 0777;
247 args.version = MSDOSFSMNT_VERSION;
248 args.dirmask = 0777;
249
250 if ((error = msdosfs_mountfs(rootvp, mp, l, &args)) != 0) {
251 vfs_unbusy(mp, false, NULL);
252 vfs_destroy(mp);
253 return (error);
254 }
255
256 if ((error = update_mp(mp, &args)) != 0) {
257 (void)msdosfs_unmount(mp, 0);
258 vfs_unbusy(mp, false, NULL);
259 vfs_destroy(mp);
260 vrele(rootvp);
261 return (error);
262 }
263
264 mountlist_append(mp);
265 (void)msdosfs_statvfs(mp, &mp->mnt_stat);
266 vfs_unbusy(mp, false, NULL);
267 return (0);
268 }
269
270 /*
271 * mp - path - addr in user space of mount point (ie /usr or whatever)
272 * data - addr in user space of mount params including the name of the block
273 * special file to treat as a filesystem.
274 */
275 int
msdosfs_mount(struct mount * mp,const char * path,void * data,size_t * data_len)276 msdosfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
277 {
278 struct lwp *l = curlwp;
279 struct vnode *devvp; /* vnode for blk device to mount */
280 struct msdosfs_args *args = data; /* holds data from mount request */
281 /* msdosfs specific mount control block */
282 struct msdosfsmount *pmp = NULL;
283 int error, flags;
284 mode_t accessmode;
285
286 if (args == NULL)
287 return EINVAL;
288 if (*data_len < sizeof *args)
289 return EINVAL;
290
291 if (mp->mnt_flag & MNT_GETARGS) {
292 pmp = VFSTOMSDOSFS(mp);
293 if (pmp == NULL)
294 return EIO;
295 args->fspec = NULL;
296 args->uid = pmp->pm_uid;
297 args->gid = pmp->pm_gid;
298 args->mask = pmp->pm_mask;
299 args->flags = pmp->pm_flags;
300 args->version = MSDOSFSMNT_VERSION;
301 args->dirmask = pmp->pm_dirmask;
302 args->gmtoff = pmp->pm_gmtoff;
303 *data_len = sizeof *args;
304 return 0;
305 }
306
307 /*
308 * If not versioned (i.e. using old mount_msdos(8)), fill in
309 * the additional structure items with suitable defaults.
310 */
311 if ((args->flags & MSDOSFSMNT_VERSIONED) == 0) {
312 args->version = 1;
313 args->dirmask = args->mask;
314 }
315
316 /*
317 * Reset GMT offset for pre-v3 mount structure args.
318 */
319 if (args->version < 3)
320 args->gmtoff = 0;
321
322 /*
323 * If updating, check whether changing from read-only to
324 * read/write; if there is no device name, that's all we do.
325 */
326 if (mp->mnt_flag & MNT_UPDATE) {
327 pmp = VFSTOMSDOSFS(mp);
328 error = 0;
329 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
330 (mp->mnt_flag & MNT_RDONLY)) {
331 flags = WRITECLOSE;
332 if (mp->mnt_flag & MNT_FORCE)
333 flags |= FORCECLOSE;
334 error = vflush(mp, NULLVP, flags);
335 }
336 if (!error && (mp->mnt_flag & MNT_RELOAD))
337 /* not yet implemented */
338 error = EOPNOTSUPP;
339 if (error) {
340 DPRINTF("vflush %d", error);
341 return (error);
342 }
343 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
344 (mp->mnt_iflag & IMNT_WANTRDWR)) {
345 /*
346 * If upgrade to read-write by non-root, then verify
347 * that user has necessary permissions on the device.
348 *
349 * Permission to update a mount is checked higher, so
350 * here we presume updating the mount is okay (for
351 * example, as far as securelevel goes) which leaves us
352 * with the normal check.
353 */
354 devvp = pmp->pm_devvp;
355 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
356 error = kauth_authorize_system(l->l_cred,
357 KAUTH_SYSTEM_MOUNT, KAUTH_REQ_SYSTEM_MOUNT_DEVICE,
358 mp, devvp, KAUTH_ARG(VREAD | VWRITE));
359 VOP_UNLOCK(devvp);
360 DPRINTF("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d", error);
361 if (error)
362 return (error);
363
364 pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
365 }
366 if (args->fspec == NULL) {
367 DPRINTF("missing fspec");
368 return EINVAL;
369 }
370 }
371 /*
372 * Not an update, or updating the name: look up the name
373 * and verify that it refers to a sensible block device.
374 */
375 error = namei_simple_user(args->fspec,
376 NSM_FOLLOW_NOEMULROOT, &devvp);
377 if (error != 0) {
378 DPRINTF("namei %d", error);
379 return (error);
380 }
381
382 if (devvp->v_type != VBLK) {
383 DPRINTF("not block");
384 vrele(devvp);
385 return (ENOTBLK);
386 }
387 if (bdevsw_lookup(devvp->v_rdev) == NULL) {
388 DPRINTF("no block switch");
389 vrele(devvp);
390 return (ENXIO);
391 }
392 /*
393 * If mount by non-root, then verify that user has necessary
394 * permissions on the device.
395 */
396 accessmode = VREAD;
397 if ((mp->mnt_flag & MNT_RDONLY) == 0)
398 accessmode |= VWRITE;
399 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
400 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
401 KAUTH_REQ_SYSTEM_MOUNT_DEVICE, mp, devvp, KAUTH_ARG(accessmode));
402 VOP_UNLOCK(devvp);
403 if (error) {
404 DPRINTF("KAUTH_REQ_SYSTEM_MOUNT_DEVICE %d", error);
405 vrele(devvp);
406 return (error);
407 }
408 if ((mp->mnt_flag & MNT_UPDATE) == 0) {
409 int xflags;
410
411 if (mp->mnt_flag & MNT_RDONLY)
412 xflags = FREAD;
413 else
414 xflags = FREAD|FWRITE;
415 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
416 error = VOP_OPEN(devvp, xflags, FSCRED);
417 VOP_UNLOCK(devvp);
418 if (error) {
419 DPRINTF("VOP_OPEN %d", error);
420 goto fail;
421 }
422 error = msdosfs_mountfs(devvp, mp, l, args);
423 if (error) {
424 DPRINTF("msdosfs_mountfs %d", error);
425 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
426 (void) VOP_CLOSE(devvp, xflags, NOCRED);
427 VOP_UNLOCK(devvp);
428 goto fail;
429 }
430 #ifdef MSDOSFS_DEBUG /* only needed for the printf below */
431 pmp = VFSTOMSDOSFS(mp);
432 #endif
433 } else {
434 vrele(devvp);
435 if (devvp != pmp->pm_devvp) {
436 DPRINTF("devvp %p pmp %p", devvp, pmp->pm_devvp);
437 return (EINVAL); /* needs translation */
438 }
439 }
440 if ((error = update_mp(mp, args)) != 0) {
441 msdosfs_unmount(mp, MNT_FORCE);
442 DPRINTF("update_mp %d", error);
443 return error;
444 }
445
446 #ifdef MSDOSFS_DEBUG
447 printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
448 #endif
449 return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
450 mp->mnt_op->vfs_name, mp, l);
451
452 fail:
453 vrele(devvp);
454 return (error);
455 }
456
457 int
msdosfs_mountfs(struct vnode * devvp,struct mount * mp,struct lwp * l,struct msdosfs_args * argp)458 msdosfs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l, struct msdosfs_args *argp)
459 {
460 struct msdosfsmount *pmp;
461 struct buf *bp;
462 dev_t dev = devvp->v_rdev;
463 union bootsector *bsp;
464 struct byte_bpb33 *b33;
465 struct byte_bpb50 *b50;
466 struct byte_bpb710 *b710;
467 uint8_t SecPerClust;
468 int ronly, error, BlkPerSec;
469 uint64_t psize;
470 unsigned secsize;
471
472 /* Flush out any old buffers remaining from a previous use. */
473 if ((error = vinvalbuf(devvp, V_SAVE, l->l_cred, l, 0, 0)) != 0)
474 return (error);
475
476 ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
477
478 bp = NULL; /* both used in error_exit */
479 pmp = NULL;
480
481 error = fstrans_mount(mp);
482 if (error)
483 goto error_exit;
484
485 error = getdisksize(devvp, &psize, &secsize);
486 if (error) {
487 if (argp->flags & MSDOSFSMNT_GEMDOSFS)
488 goto error_exit;
489
490 /* ok, so it failed. we most likely don't need the info */
491 secsize = DEV_BSIZE;
492 psize = 0;
493 error = 0;
494 }
495 if (secsize < DEV_BSIZE) {
496 DPRINTF("Invalid block secsize (%d < DEV_BSIZE)", secsize);
497 error = EINVAL;
498 goto error_exit;
499 }
500
501 if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
502 if (secsize != GEMDOSFS_BSIZE) {
503 DPRINTF("Invalid block secsize %d for GEMDOS", secsize);
504 error = EINVAL;
505 goto error_exit;
506 }
507 }
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 (secsize < sizeof(*b50)) {
514 DPRINTF("50 bootsec %u\n", secsize);
515 error = EINVAL;
516 goto error_exit;
517 }
518 if ((error = bread(devvp, 0, secsize, 0, &bp)) != 0)
519 goto error_exit;
520 bsp = (union bootsector *)bp->b_data;
521 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
522 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
523 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
524
525 if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
526 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
527 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
528 DPRINTF("bootsig0 %d bootsig1 %d",
529 bsp->bs50.bsBootSectSig0,
530 bsp->bs50.bsBootSectSig1);
531 error = EINVAL;
532 goto error_exit;
533 }
534 }
535
536 pmp = malloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK|M_ZERO);
537 pmp->pm_mountp = mp;
538
539 /*
540 * Compute several useful quantities from the bpb in the
541 * bootsector. Copy in the dos 5 variant of the bpb then fix up
542 * the fields that are different between dos 5 and dos 3.3.
543 */
544 SecPerClust = b50->bpbSecPerClust;
545 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
546 pmp->pm_ResSectors = getushort(b50->bpbResSectors);
547 pmp->pm_FATs = b50->bpbFATs;
548 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
549 pmp->pm_Sectors = getushort(b50->bpbSectors);
550 pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
551 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
552 pmp->pm_Heads = getushort(b50->bpbHeads);
553 pmp->pm_Media = b50->bpbMedia;
554
555 if (pmp->pm_Sectors == 0) {
556 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
557 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
558 } else {
559 if (secsize < sizeof(*b33)) {
560 DPRINTF("33 bootsec %u\n", secsize);
561 error = EINVAL;
562 goto error_exit;
563 }
564 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
565 pmp->pm_HugeSectors = pmp->pm_Sectors;
566 }
567
568 /*
569 * Sanity checks, from the FAT specification:
570 * - sectors per cluster: >= 1, power of 2
571 * - logical sector size: >= 1, power of 2
572 * - cluster size: <= max FS block size
573 * - number of sectors: >= 1
574 */
575 if ((SecPerClust == 0) || !powerof2(SecPerClust) ||
576 (pmp->pm_BytesPerSec == 0) || !powerof2(pmp->pm_BytesPerSec) ||
577 (SecPerClust * pmp->pm_BytesPerSec > MAXBSIZE) ||
578 (pmp->pm_HugeSectors == 0)) {
579 DPRINTF("consistency checks");
580 error = EINVAL;
581 goto error_exit;
582 }
583
584 if (!(argp->flags & MSDOSFSMNT_GEMDOSFS) &&
585 (pmp->pm_SecPerTrack > 63)) {
586 DPRINTF("SecPerTrack %d", pmp->pm_SecPerTrack);
587 error = EINVAL;
588 goto error_exit;
589 }
590
591 if (pmp->pm_RootDirEnts == 0) {
592 if (secsize < sizeof(*b710)) {
593 DPRINTF("710 bootsec %u\n", secsize);
594 error = EINVAL;
595 goto error_exit;
596 }
597 unsigned short FSVers = getushort(b710->bpbFSVers);
598 unsigned short ExtFlags = getushort(b710->bpbExtFlags);
599 /*
600 * Some say that bsBootSectSig[23] must be zero, but
601 * Windows does not require this and some digital cameras
602 * do not set these to zero. Therefore, do not insist.
603 */
604 if (pmp->pm_Sectors || pmp->pm_FATsecs || FSVers) {
605 DPRINTF("Sectors %d FATsecs %lu FSVers %d",
606 pmp->pm_Sectors, pmp->pm_FATsecs, FSVers);
607 error = EINVAL;
608 goto error_exit;
609 }
610 pmp->pm_fatmask = FAT32_MASK;
611 pmp->pm_fatmult = 4;
612 pmp->pm_fatdiv = 1;
613 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
614
615 /* Mirroring is enabled if the FATMIRROR bit is not set. */
616 if ((ExtFlags & FATMIRROR) == 0)
617 pmp->pm_flags |= MSDOSFS_FATMIRROR;
618 else
619 pmp->pm_curfat = ExtFlags & FATNUM;
620 } else
621 pmp->pm_flags |= MSDOSFS_FATMIRROR;
622
623 if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
624 if (FAT32(pmp)) {
625 /* GEMDOS doesn't know FAT32. */
626 DPRINTF("FAT32 for GEMDOS");
627 error = EINVAL;
628 goto error_exit;
629 }
630
631 /*
632 * Check a few values (could do some more):
633 * - logical sector size: >= block size
634 * - number of sectors: <= size of partition
635 */
636 if ((pmp->pm_BytesPerSec < GEMDOSFS_BSIZE) ||
637 (pmp->pm_HugeSectors *
638 (pmp->pm_BytesPerSec / GEMDOSFS_BSIZE) > psize)) {
639 DPRINTF("consistency checks for GEMDOS");
640 error = EINVAL;
641 goto error_exit;
642 }
643 /*
644 * XXX - Many parts of the msdosfs driver seem to assume that
645 * the number of bytes per logical sector (BytesPerSec) will
646 * always be the same as the number of bytes per disk block
647 * Let's pretend it is.
648 */
649 BlkPerSec = pmp->pm_BytesPerSec / GEMDOSFS_BSIZE;
650 pmp->pm_BytesPerSec = GEMDOSFS_BSIZE;
651 pmp->pm_HugeSectors *= BlkPerSec;
652 pmp->pm_HiddenSects *= BlkPerSec;
653 pmp->pm_ResSectors *= BlkPerSec;
654 pmp->pm_Sectors *= BlkPerSec;
655 pmp->pm_FATsecs *= BlkPerSec;
656 SecPerClust *= BlkPerSec;
657 }
658
659 /* Check that fs has nonzero FAT size */
660 if (pmp->pm_FATsecs == 0) {
661 DPRINTF("FATsecs is 0");
662 error = EINVAL;
663 goto error_exit;
664 }
665
666 pmp->pm_fatblk = pmp->pm_ResSectors;
667 if (FAT32(pmp)) {
668 if (secsize < sizeof(*b710)) {
669 DPRINTF("710 bootsec %u\n", secsize);
670 error = EINVAL;
671 goto error_exit;
672 }
673 pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
674 pmp->pm_firstcluster = pmp->pm_fatblk
675 + (pmp->pm_FATs * pmp->pm_FATsecs);
676 pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
677 } else {
678 pmp->pm_rootdirblk = pmp->pm_fatblk +
679 (pmp->pm_FATs * pmp->pm_FATsecs);
680 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
681 + pmp->pm_BytesPerSec - 1)
682 / pmp->pm_BytesPerSec;/* in sectors */
683 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
684 }
685
686 pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
687 SecPerClust;
688 pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
689 pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
690
691 if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
692 if (pmp->pm_nmbrofclusters <= (0xff0 - 2)) {
693 pmp->pm_fatmask = FAT12_MASK;
694 pmp->pm_fatmult = 3;
695 pmp->pm_fatdiv = 2;
696 } else {
697 pmp->pm_fatmask = FAT16_MASK;
698 pmp->pm_fatmult = 2;
699 pmp->pm_fatdiv = 1;
700 }
701 } else if (pmp->pm_fatmask == 0) {
702 if (pmp->pm_maxcluster
703 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
704 /*
705 * This will usually be a floppy disk. This size makes
706 * sure that one FAT entry will not be split across
707 * multiple blocks.
708 */
709 pmp->pm_fatmask = FAT12_MASK;
710 pmp->pm_fatmult = 3;
711 pmp->pm_fatdiv = 2;
712 } else {
713 pmp->pm_fatmask = FAT16_MASK;
714 pmp->pm_fatmult = 2;
715 pmp->pm_fatdiv = 1;
716 }
717 }
718 if (FAT12(pmp))
719 pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
720 else
721 pmp->pm_fatblocksize = MAXBSIZE;
722
723 pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
724 pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
725
726 /*
727 * Compute mask and shift value for isolating cluster relative byte
728 * offsets and cluster numbers from a file offset.
729 */
730 pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
731 pmp->pm_crbomask = pmp->pm_bpcluster - 1;
732 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
733
734 /*
735 * Check for valid cluster size
736 * must be a power of 2
737 */
738 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
739 DPRINTF("bpcluster %lu cnshift %lu", pmp->pm_bpcluster,
740 pmp->pm_cnshift);
741 error = EINVAL;
742 goto error_exit;
743 }
744
745 /*
746 * Cluster size must be within limit of MAXBSIZE.
747 * Many FAT filesystems will not have clusters larger than
748 * 32KiB due to limits in Windows versions before Vista.
749 */
750 if (pmp->pm_bpcluster > MAXBSIZE) {
751 DPRINTF("bpcluster %lu > MAXBSIZE %d",
752 pmp->pm_bpcluster, MAXBSIZE);
753 error = EINVAL;
754 goto error_exit;
755 }
756
757 /*
758 * Release the bootsector buffer.
759 */
760 brelse(bp, BC_AGE);
761 bp = NULL;
762
763 /*
764 * Check FSInfo.
765 */
766 if (pmp->pm_fsinfo) {
767 struct fsinfo *fp;
768 const int rdsz = roundup(sizeof(*fp), pmp->pm_BytesPerSec);
769
770 /*
771 * XXX If the fsinfo block is stored on media with
772 * 2KB or larger sectors, is the fsinfo structure
773 * padded at the end or in the middle?
774 */
775 if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo),
776 rdsz, 0, &bp)) != 0)
777 goto error_exit;
778 fp = (struct fsinfo *)bp->b_data;
779 if (!memcmp(fp->fsisig1, "RRaA", 4)
780 && !memcmp(fp->fsisig2, "rrAa", 4)
781 && !memcmp(fp->fsisig3, "\0\0\125\252", 4)
782 && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
783 pmp->pm_nxtfree = getulong(fp->fsinxtfree);
784 else
785 pmp->pm_fsinfo = 0;
786 brelse(bp, 0);
787 bp = NULL;
788 }
789
790 /*
791 * Check and validate (or perhaps invalidate?) the fsinfo structure?
792 * XXX
793 */
794 if (pmp->pm_fsinfo) {
795 if ((pmp->pm_nxtfree == 0xffffffffUL) ||
796 (pmp->pm_nxtfree > pmp->pm_maxcluster))
797 pmp->pm_fsinfo = 0;
798 }
799
800 /*
801 * Allocate memory for the bitmap of allocated clusters, and then
802 * fill it in.
803 */
804 pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS)
805 / N_INUSEBITS)
806 * sizeof(*pmp->pm_inusemap),
807 M_MSDOSFSFAT, M_WAITOK);
808
809 /*
810 * fillinusemap() needs pm_devvp.
811 */
812 pmp->pm_dev = dev;
813 pmp->pm_devvp = devvp;
814
815 /*
816 * Have the inuse map filled in.
817 */
818 if ((error = fillinusemap(pmp)) != 0) {
819 DPRINTF("fillinusemap %d", error);
820 goto error_exit;
821 }
822
823 /*
824 * If they want FAT updates to be synchronous then let them suffer
825 * the performance degradation in exchange for the on disk copy of
826 * the FAT being correct just about all the time. I suppose this
827 * would be a good thing to turn on if the kernel is still flakey.
828 */
829 if (mp->mnt_flag & MNT_SYNCHRONOUS)
830 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
831
832 /*
833 * Finish up.
834 */
835 if (ronly)
836 pmp->pm_flags |= MSDOSFSMNT_RONLY;
837 else
838 pmp->pm_fmod = 1;
839 mp->mnt_data = pmp;
840 mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
841 mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_MSDOS);
842 mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
843 mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
844 mp->mnt_flag |= MNT_LOCAL;
845 mp->mnt_dev_bshift = pmp->pm_bnshift;
846 mp->mnt_fs_bshift = pmp->pm_cnshift;
847
848 /*
849 * If we ever do quotas for DOS filesystems this would be a place
850 * to fill in the info in the msdosfsmount structure. You dolt,
851 * quotas on dos filesystems make no sense because files have no
852 * owners on dos filesystems. of course there is some empty space
853 * in the directory entry where we could put uid's and gid's.
854 */
855
856 spec_node_setmountedfs(devvp, mp);
857
858 return (0);
859
860 error_exit:
861 fstrans_unmount(mp);
862 if (bp)
863 brelse(bp, BC_AGE);
864 if (pmp) {
865 if (pmp->pm_inusemap)
866 free(pmp->pm_inusemap, M_MSDOSFSFAT);
867 free(pmp, M_MSDOSFSMNT);
868 mp->mnt_data = NULL;
869 }
870 return (error);
871 }
872
873 int
msdosfs_start(struct mount * mp,int flags)874 msdosfs_start(struct mount *mp, int flags)
875 {
876
877 return (0);
878 }
879
880 /*
881 * Unmount the filesystem described by mp.
882 */
883 int
msdosfs_unmount(struct mount * mp,int mntflags)884 msdosfs_unmount(struct mount *mp, int mntflags)
885 {
886 struct msdosfsmount *pmp;
887 int error, flags;
888
889 flags = 0;
890 if (mntflags & MNT_FORCE)
891 flags |= FORCECLOSE;
892 if ((error = vflush(mp, NULLVP, flags)) != 0)
893 return (error);
894 pmp = VFSTOMSDOSFS(mp);
895 if (pmp->pm_devvp->v_type != VBAD)
896 spec_node_setmountedfs(pmp->pm_devvp, NULL);
897 #ifdef MSDOSFS_DEBUG
898 {
899 struct vnode *vp = pmp->pm_devvp;
900
901 printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
902 printf("flag %08x, usecount %d, writecount %d, holdcnt %d\n",
903 vp->v_vflag | vp->v_iflag | vp->v_uflag, vp->v_usecount,
904 vp->v_writecount, vp->v_holdcnt);
905 printf("mount %p, op %p\n",
906 vp->v_mount, vp->v_op);
907 printf("freef %p, freeb %p, mount %p\n",
908 vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
909 vp->v_mount);
910 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
911 vp->v_cleanblkhd.lh_first,
912 vp->v_dirtyblkhd.lh_first,
913 vp->v_numoutput, vp->v_type);
914 printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
915 vp->v_socket, vp->v_tag,
916 ((u_int *)vp->v_data)[0],
917 ((u_int *)vp->v_data)[1]);
918 }
919 #endif
920 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
921 (void) VOP_CLOSE(pmp->pm_devvp,
922 pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED);
923 vput(pmp->pm_devvp);
924 msdosfs_fh_destroy(pmp);
925 free(pmp->pm_inusemap, M_MSDOSFSFAT);
926 free(pmp, M_MSDOSFSMNT);
927 mp->mnt_data = NULL;
928 mp->mnt_flag &= ~MNT_LOCAL;
929 fstrans_unmount(mp);
930 return (0);
931 }
932
933 int
msdosfs_root(struct mount * mp,struct vnode ** vpp)934 msdosfs_root(struct mount *mp, struct vnode **vpp)
935 {
936 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
937 int error;
938
939 #ifdef MSDOSFS_DEBUG
940 printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
941 #endif
942 if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, vpp)) != 0)
943 return error;
944 error = vn_lock(*vpp, LK_EXCLUSIVE);
945 if (error) {
946 vrele(*vpp);
947 *vpp = NULL;
948 return error;
949 }
950 return 0;
951 }
952
953 int
msdosfs_statvfs(struct mount * mp,struct statvfs * sbp)954 msdosfs_statvfs(struct mount *mp, struct statvfs *sbp)
955 {
956 struct msdosfsmount *pmp;
957
958 pmp = VFSTOMSDOSFS(mp);
959 sbp->f_bsize = pmp->pm_bpcluster;
960 sbp->f_frsize = sbp->f_bsize;
961 sbp->f_iosize = pmp->pm_bpcluster;
962 sbp->f_blocks = pmp->pm_nmbrofclusters;
963 sbp->f_bfree = pmp->pm_freeclustercount;
964 sbp->f_bavail = pmp->pm_freeclustercount;
965 sbp->f_bresvd = 0;
966 sbp->f_files = pmp->pm_RootDirEnts; /* XXX */
967 sbp->f_ffree = 0; /* what to put in here? */
968 sbp->f_favail = 0; /* what to put in here? */
969 sbp->f_fresvd = 0;
970 copy_statvfs_info(sbp, mp);
971 return (0);
972 }
973
974 struct msdosfs_sync_ctx {
975 int waitfor;
976 };
977
978 static bool
msdosfs_sync_selector(void * cl,struct vnode * vp)979 msdosfs_sync_selector(void *cl, struct vnode *vp)
980 {
981 struct msdosfs_sync_ctx *c = cl;
982 struct denode *dep;
983
984 dep = VTODE(vp);
985 if (c->waitfor == MNT_LAZY || vp->v_type == VNON ||
986 dep == NULL || (((dep->de_flag &
987 (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
988 (LIST_EMPTY(&vp->v_dirtyblkhd) &&
989 UVM_OBJ_IS_CLEAN(&vp->v_uobj))))
990 return false;
991 return true;
992 }
993
994 int
msdosfs_sync(struct mount * mp,int waitfor,kauth_cred_t cred)995 msdosfs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
996 {
997 struct vnode *vp;
998 struct vnode_iterator *marker;
999 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
1000 int error, allerror = 0;
1001 struct msdosfs_sync_ctx ctx;
1002
1003 /*
1004 * If we ever switch to not updating all of the FATs all the time,
1005 * this would be the place to update them from the first one.
1006 */
1007 if (pmp->pm_fmod != 0) {
1008 if (pmp->pm_flags & MSDOSFSMNT_RONLY)
1009 panic("msdosfs_sync: rofs mod");
1010 else {
1011 /* update FATs here */
1012 }
1013 }
1014 fstrans_start(mp, FSTRANS_SHARED);
1015 /*
1016 * Write back each (modified) denode.
1017 */
1018 vfs_vnode_iterator_init(mp, &marker);
1019 ctx.waitfor = waitfor;
1020 while ((vp = vfs_vnode_iterator_next(marker, msdosfs_sync_selector,
1021 &ctx)))
1022 {
1023 error = vn_lock(vp, LK_EXCLUSIVE);
1024 if (error) {
1025 vrele(vp);
1026 continue;
1027 }
1028 if ((error = VOP_FSYNC(vp, cred,
1029 waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
1030 allerror = error;
1031 vput(vp);
1032 }
1033 vfs_vnode_iterator_destroy(marker);
1034
1035 /*
1036 * Force stale file system control information to be flushed.
1037 */
1038 if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
1039 waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
1040 allerror = error;
1041 fstrans_done(mp);
1042 return (allerror);
1043 }
1044
1045 int
msdosfs_fhtovp(struct mount * mp,struct fid * fhp,struct vnode ** vpp)1046 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
1047 {
1048 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
1049 struct defid defh;
1050 uint32_t gen;
1051 int error;
1052
1053 if (fhp->fid_len != sizeof(struct defid)) {
1054 DPRINTF("fid_len %d %zd", fhp->fid_len, sizeof(struct defid));
1055 return EINVAL;
1056 }
1057 memcpy(&defh, fhp, sizeof(defh));
1058 error = msdosfs_fh_lookup(pmp, defh.defid_dirclust, defh.defid_dirofs,
1059 &gen);
1060 if (error == 0 && gen != defh.defid_gen)
1061 error = ESTALE;
1062 if (error) {
1063 *vpp = NULLVP;
1064 return error;
1065 }
1066 error = deget(pmp, defh.defid_dirclust, defh.defid_dirofs, vpp);
1067 if (error) {
1068 DPRINTF("deget %d", error);
1069 *vpp = NULLVP;
1070 return error;
1071 }
1072 error = vn_lock(*vpp, LK_EXCLUSIVE);
1073 if (error) {
1074 vrele(*vpp);
1075 *vpp = NULLVP;
1076 return error;
1077 }
1078 return 0;
1079 }
1080
1081 int
msdosfs_vptofh(struct vnode * vp,struct fid * fhp,size_t * fh_size)1082 msdosfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
1083 {
1084 struct msdosfsmount *pmp = VFSTOMSDOSFS(vp->v_mount);
1085 struct denode *dep;
1086 struct defid defh;
1087 int error;
1088
1089 if (*fh_size < sizeof(struct defid)) {
1090 *fh_size = sizeof(struct defid);
1091 return E2BIG;
1092 }
1093 *fh_size = sizeof(struct defid);
1094 dep = VTODE(vp);
1095 memset(&defh, 0, sizeof(defh));
1096 defh.defid_len = sizeof(struct defid);
1097 defh.defid_dirclust = dep->de_dirclust;
1098 defh.defid_dirofs = dep->de_diroffset;
1099 error = msdosfs_fh_enter(pmp, dep->de_dirclust, dep->de_diroffset,
1100 &defh.defid_gen);
1101 if (error == 0)
1102 memcpy(fhp, &defh, sizeof(defh));
1103 return error;
1104 }
1105
1106 int
msdosfs_vget(struct mount * mp,ino_t ino,struct vnode ** vpp)1107 msdosfs_vget(struct mount *mp, ino_t ino,
1108 struct vnode **vpp)
1109 {
1110
1111 return (EOPNOTSUPP);
1112 }
1113
1114 int
msdosfs_suspendctl(struct mount * mp,int cmd)1115 msdosfs_suspendctl(struct mount *mp, int cmd)
1116 {
1117 int error;
1118 struct lwp *l = curlwp;
1119
1120 switch (cmd) {
1121 case SUSPEND_SUSPEND:
1122 if ((error = fstrans_setstate(mp, FSTRANS_SUSPENDING)) != 0)
1123 return error;
1124 error = msdosfs_sync(mp, MNT_WAIT, l->l_proc->p_cred);
1125 if (error == 0)
1126 error = fstrans_setstate(mp, FSTRANS_SUSPENDED);
1127 if (error != 0) {
1128 (void) fstrans_setstate(mp, FSTRANS_NORMAL);
1129 return error;
1130 }
1131 return 0;
1132
1133 case SUSPEND_RESUME:
1134 return fstrans_setstate(mp, FSTRANS_NORMAL);
1135
1136 default:
1137 return EINVAL;
1138 }
1139 }
1140