1 /* $NetBSD: msdosfs_vfsops.c,v 1.138 2022/04/16 07:58:21 hannken 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 1.138 2022/04/16 07:58:21 hannken 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/ioctl.h>
73 #include <sys/malloc.h>
74 #include <sys/dirent.h>
75 #include <sys/stat.h>
76 #include <sys/conf.h>
77 #include <sys/kauth.h>
78 #include <sys/module.h>
79
80 #include <fs/msdosfs/bpb.h>
81 #include <fs/msdosfs/bootsect.h>
82 #include <fs/msdosfs/direntry.h>
83 #include <fs/msdosfs/denode.h>
84 #include <fs/msdosfs/msdosfsmount.h>
85 #include <fs/msdosfs/fat.h>
86
87 MODULE(MODULE_CLASS_VFS, msdos, NULL);
88
89 #ifdef MSDOSFS_DEBUG
90 #define DPRINTF(fmt, ...) uprintf("%s(): " fmt "\n", __func__, ##__VA_ARGS__)
91 #else
92 #define DPRINTF(fmt, ...)
93 #endif
94
95 #define GEMDOSFS_BSIZE 512
96
97 #define MSDOSFS_NAMEMAX(pmp) \
98 (pmp)->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12
99
100 int msdosfs_mountfs(struct vnode *, struct mount *, struct lwp *,
101 struct msdosfs_args *);
102
103 static int update_mp(struct mount *, struct msdosfs_args *);
104
105 MALLOC_JUSTDEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOS FS mount structure");
106 MALLOC_JUSTDEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOS FS FAT table");
107 MALLOC_JUSTDEFINE(M_MSDOSFSTMP, "MSDOSFS temp", "MSDOS FS temp. structures");
108
109 extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc;
110
111 const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = {
112 &msdosfs_vnodeop_opv_desc,
113 NULL,
114 };
115
116 struct vfsops msdosfs_vfsops = {
117 .vfs_name = MOUNT_MSDOS,
118 .vfs_min_mount_data = sizeof (struct msdosfs_args),
119 .vfs_mount = msdosfs_mount,
120 .vfs_start = msdosfs_start,
121 .vfs_unmount = msdosfs_unmount,
122 .vfs_root = msdosfs_root,
123 .vfs_quotactl = (void *)eopnotsupp,
124 .vfs_statvfs = msdosfs_statvfs,
125 .vfs_sync = msdosfs_sync,
126 .vfs_vget = msdosfs_vget,
127 .vfs_loadvnode = msdosfs_loadvnode,
128 .vfs_fhtovp = msdosfs_fhtovp,
129 .vfs_vptofh = msdosfs_vptofh,
130 .vfs_init = msdosfs_init,
131 .vfs_reinit = msdosfs_reinit,
132 .vfs_done = msdosfs_done,
133 .vfs_mountroot = msdosfs_mountroot,
134 .vfs_snapshot = (void *)eopnotsupp,
135 .vfs_extattrctl = vfs_stdextattrctl,
136 .vfs_suspendctl = genfs_suspendctl,
137 .vfs_renamelock_enter = genfs_renamelock_enter,
138 .vfs_renamelock_exit = genfs_renamelock_exit,
139 .vfs_fsync = (void *)eopnotsupp,
140 .vfs_opv_descs = msdosfs_vnodeopv_descs
141 };
142
143 SYSCTL_SETUP(msdosfs_sysctl_setup, "msdosfs sysctl")
144 {
145 sysctl_createv(clog, 0, NULL, NULL,
146 CTLFLAG_PERMANENT,
147 CTLTYPE_NODE, "msdosfs",
148 SYSCTL_DESCR("MS-DOS file system"),
149 NULL, 0, NULL, 0,
150 CTL_VFS, 4, CTL_EOL);
151 /*
152 * XXX the "4" above could be dynamic, thereby eliminating one
153 * more instance of the "number to vfs" mapping problem, but
154 * "4" is the order as taken from sys/mount.h
155 */
156 }
157
158 static int
msdos_modcmd(modcmd_t cmd,void * arg)159 msdos_modcmd(modcmd_t cmd, void *arg)
160 {
161 int error;
162
163 switch (cmd) {
164 case MODULE_CMD_INIT:
165 error = vfs_attach(&msdosfs_vfsops);
166 if (error != 0)
167 break;
168 break;
169 case MODULE_CMD_FINI:
170 error = vfs_detach(&msdosfs_vfsops);
171 if (error != 0)
172 break;
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 error = msdosfs_root(mp, LK_EXCLUSIVE, &rtvp);
214 if (error != 0)
215 return error;
216 pmp->pm_flags |= msdosfs_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
msdosfs_mountroot(void)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);
253 vfs_rele(mp);
254 return (error);
255 }
256
257 if ((error = update_mp(mp, &args)) != 0) {
258 (void)msdosfs_unmount(mp, 0);
259 vfs_unbusy(mp);
260 vfs_rele(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);
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
msdosfs_mount(struct mount * mp,const char * path,void * data,size_t * data_len)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", 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", error);
362 if (error)
363 return (error);
364
365 pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
366 }
367 if (args->fspec == NULL) {
368 DPRINTF("missing fspec");
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", error);
380 return (error);
381 }
382
383 if (devvp->v_type != VBLK) {
384 DPRINTF("not block");
385 vrele(devvp);
386 return (ENOTBLK);
387 }
388 if (bdevsw_lookup(devvp->v_rdev) == NULL) {
389 DPRINTF("no block switch");
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", 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", error);
421 goto fail;
422 }
423 error = msdosfs_mountfs(devvp, mp, l, args);
424 if (error) {
425 DPRINTF("msdosfs_mountfs %d", 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", devvp, pmp->pm_devvp);
438 return (EINVAL); /* needs translation */
439 }
440 }
441 if ((error = update_mp(mp, args)) != 0) {
442 msdosfs_unmount(mp, MNT_FORCE);
443 DPRINTF("update_mp %d", error);
444 return error;
445 }
446
447 #ifdef MSDOSFS_DEBUG
448 printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
449 #endif
450 return set_statvfs_info(path, UIO_USERSPACE, args->fspec, UIO_USERSPACE,
451 mp->mnt_op->vfs_name, mp, l);
452
453 fail:
454 vrele(devvp);
455 return (error);
456 }
457
458 int
msdosfs_mountfs(struct vnode * devvp,struct mount * mp,struct lwp * l,struct msdosfs_args * argp)459 msdosfs_mountfs(struct vnode *devvp, struct mount *mp, struct lwp *l, struct msdosfs_args *argp)
460 {
461 struct msdosfsmount *pmp;
462 struct buf *bp;
463 dev_t dev = devvp->v_rdev;
464 union bootsector *bsp;
465 struct byte_bpb33 *b33;
466 struct byte_bpb50 *b50;
467 struct byte_bpb710 *b710;
468 uint8_t SecPerClust;
469 int ronly, error, BlkPerSec;
470 uint64_t psize;
471 unsigned secsize;
472 u_long fatbytes, fatblocksecs;
473
474 /* Flush out any old buffers remaining from a previous use. */
475 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
476 error = vinvalbuf(devvp, V_SAVE, l->l_cred, l, 0, 0);
477 VOP_UNLOCK(devvp);
478 if (error)
479 return (error);
480
481 ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
482
483 bp = NULL; /* both used in error_exit */
484 pmp = NULL;
485
486 error = getdisksize(devvp, &psize, &secsize);
487 if (error) {
488 if (argp->flags & MSDOSFSMNT_GEMDOSFS)
489 goto error_exit;
490
491 /* ok, so it failed. we most likely don't need the info */
492 secsize = DEV_BSIZE;
493 psize = 0;
494 error = 0;
495 }
496 if (secsize < DEV_BSIZE) {
497 DPRINTF("Invalid block secsize (%d < DEV_BSIZE)", secsize);
498 error = EINVAL;
499 goto error_exit;
500 }
501
502 if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
503 if (secsize != GEMDOSFS_BSIZE) {
504 DPRINTF("Invalid block secsize %d for GEMDOS", secsize);
505 error = EINVAL;
506 goto error_exit;
507 }
508 }
509
510 /*
511 * Read the boot sector of the filesystem, and then check the
512 * boot signature. If not a dos boot sector then error out.
513 */
514 if (secsize < sizeof(*b50)) {
515 DPRINTF("50 bootsec %u\n", secsize);
516 error = EINVAL;
517 goto error_exit;
518 }
519 if ((error = bread(devvp, 0, secsize, 0, &bp)) != 0)
520 goto error_exit;
521 bsp = (union bootsector *)bp->b_data;
522 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
523 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
524 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
525
526 #if 0
527 /*
528 * Some FAT partition, for example Raspberry Pi Pico's
529 * USB mass storage, does not have exptected BOOTSIGs.
530 * According to FreeBSD's comment, some PC-9800/9821
531 * FAT floppy disks have similar problems.
532 */
533 if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
534 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
535 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
536 DPRINTF("bootsig0 %d bootsig1 %d",
537 bsp->bs50.bsBootSectSig0,
538 bsp->bs50.bsBootSectSig1);
539 error = EINVAL;
540 goto error_exit;
541 }
542 }
543 #endif
544
545 pmp = malloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK|M_ZERO);
546 pmp->pm_mountp = mp;
547
548 /*
549 * Compute several useful quantities from the bpb in the
550 * bootsector. Copy in the dos 5 variant of the bpb then fix up
551 * the fields that are different between dos 5 and dos 3.3.
552 */
553 SecPerClust = b50->bpbSecPerClust;
554 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
555 pmp->pm_ResSectors = getushort(b50->bpbResSectors);
556 pmp->pm_FATs = b50->bpbFATs;
557 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
558 pmp->pm_Sectors = getushort(b50->bpbSectors);
559 pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
560 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
561 pmp->pm_Heads = getushort(b50->bpbHeads);
562 pmp->pm_Media = b50->bpbMedia;
563
564 if (pmp->pm_Sectors == 0) {
565 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
566 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
567 } else {
568 if (secsize < sizeof(*b33)) {
569 DPRINTF("33 bootsec %u\n", secsize);
570 error = EINVAL;
571 goto error_exit;
572 }
573 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
574 pmp->pm_HugeSectors = pmp->pm_Sectors;
575 }
576
577 /*
578 * Sanity checks, from the FAT specification:
579 * - sectors per cluster: >= 1, power of 2
580 * - logical sector size: >= 1, power of 2
581 * - cluster size: <= max FS block size
582 * - number of sectors: >= 1
583 */
584 if ((SecPerClust == 0) || !powerof2(SecPerClust) ||
585 (pmp->pm_BytesPerSec == 0) || !powerof2(pmp->pm_BytesPerSec) ||
586 (SecPerClust * pmp->pm_BytesPerSec > MAXBSIZE) ||
587 (pmp->pm_HugeSectors == 0)) {
588 DPRINTF("consistency checks");
589 error = EINVAL;
590 goto error_exit;
591 }
592
593 if (!(argp->flags & MSDOSFSMNT_GEMDOSFS) &&
594 (pmp->pm_SecPerTrack > 63)) {
595 DPRINTF("SecPerTrack %d", pmp->pm_SecPerTrack);
596 error = EINVAL;
597 goto error_exit;
598 }
599
600 if (pmp->pm_RootDirEnts == 0) {
601 if (secsize < sizeof(*b710)) {
602 DPRINTF("710 bootsec %u\n", secsize);
603 error = EINVAL;
604 goto error_exit;
605 }
606 unsigned short FSVers = getushort(b710->bpbFSVers);
607 unsigned short ExtFlags = getushort(b710->bpbExtFlags);
608 /*
609 * Some say that bsBootSectSig[23] must be zero, but
610 * Windows does not require this and some digital cameras
611 * do not set these to zero. Therefore, do not insist.
612 */
613 if (pmp->pm_Sectors || pmp->pm_FATsecs || FSVers) {
614 DPRINTF("Sectors %d FATsecs %lu FSVers %d",
615 pmp->pm_Sectors, pmp->pm_FATsecs, FSVers);
616 error = EINVAL;
617 goto error_exit;
618 }
619 pmp->pm_fatmask = FAT32_MASK;
620 pmp->pm_fatmult = 4;
621 pmp->pm_fatdiv = 1;
622 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
623
624 /* Mirroring is enabled if the FATMIRROR bit is not set. */
625 if ((ExtFlags & FATMIRROR) == 0)
626 pmp->pm_flags |= MSDOSFS_FATMIRROR;
627 else
628 pmp->pm_curfat = ExtFlags & FATNUM;
629 } else
630 pmp->pm_flags |= MSDOSFS_FATMIRROR;
631
632 if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
633 if (FAT32(pmp)) {
634 /* GEMDOS doesn't know FAT32. */
635 DPRINTF("FAT32 for GEMDOS");
636 error = EINVAL;
637 goto error_exit;
638 }
639
640 /*
641 * Check a few values (could do some more):
642 * - logical sector size: >= block size
643 * - number of sectors: <= size of partition
644 */
645 if ((pmp->pm_BytesPerSec < GEMDOSFS_BSIZE) ||
646 (pmp->pm_HugeSectors *
647 (pmp->pm_BytesPerSec / GEMDOSFS_BSIZE) > psize)) {
648 DPRINTF("consistency checks for GEMDOS");
649 error = EINVAL;
650 goto error_exit;
651 }
652 /*
653 * XXX - Many parts of the msdosfs driver seem to assume that
654 * the number of bytes per logical sector (BytesPerSec) will
655 * always be the same as the number of bytes per disk block
656 * Let's pretend it is.
657 */
658 BlkPerSec = pmp->pm_BytesPerSec / GEMDOSFS_BSIZE;
659 pmp->pm_BytesPerSec = GEMDOSFS_BSIZE;
660 pmp->pm_HugeSectors *= BlkPerSec;
661 pmp->pm_HiddenSects *= BlkPerSec;
662 pmp->pm_ResSectors *= BlkPerSec;
663 pmp->pm_Sectors *= BlkPerSec;
664 pmp->pm_FATsecs *= BlkPerSec;
665 SecPerClust *= BlkPerSec;
666 }
667
668 /* Check that fs has nonzero FAT size */
669 if (pmp->pm_FATsecs == 0) {
670 DPRINTF("FATsecs is 0");
671 error = EINVAL;
672 goto error_exit;
673 }
674
675 pmp->pm_fatblk = pmp->pm_ResSectors;
676 if (FAT32(pmp)) {
677 if (secsize < sizeof(*b710)) {
678 DPRINTF("710 bootsec %u\n", secsize);
679 error = EINVAL;
680 goto error_exit;
681 }
682 pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
683 pmp->pm_firstcluster = pmp->pm_fatblk
684 + (pmp->pm_FATs * pmp->pm_FATsecs);
685 pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
686 } else {
687 pmp->pm_rootdirblk = pmp->pm_fatblk +
688 (pmp->pm_FATs * pmp->pm_FATsecs);
689 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
690 + pmp->pm_BytesPerSec - 1)
691 / pmp->pm_BytesPerSec;/* in sectors */
692 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
693 }
694
695 pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
696 SecPerClust;
697 pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
698 pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
699
700 if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
701 if (pmp->pm_nmbrofclusters <= (0xff0 - 2)) {
702 pmp->pm_fatmask = FAT12_MASK;
703 pmp->pm_fatmult = 3;
704 pmp->pm_fatdiv = 2;
705 } else {
706 pmp->pm_fatmask = FAT16_MASK;
707 pmp->pm_fatmult = 2;
708 pmp->pm_fatdiv = 1;
709 }
710 } else if (pmp->pm_fatmask == 0) {
711 if (pmp->pm_maxcluster
712 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
713 /*
714 * This will usually be a floppy disk. This size makes
715 * sure that one FAT entry will not be split across
716 * multiple blocks.
717 */
718 pmp->pm_fatmask = FAT12_MASK;
719 pmp->pm_fatmult = 3;
720 pmp->pm_fatdiv = 2;
721 } else {
722 pmp->pm_fatmask = FAT16_MASK;
723 pmp->pm_fatmult = 2;
724 pmp->pm_fatdiv = 1;
725 }
726 }
727
728 /* validate cluster count against FAT */
729 if ((pmp->pm_maxcluster & pmp->pm_fatmask) != pmp->pm_maxcluster) {
730 DPRINTF("maxcluster %lu outside of mask %#lx\n",
731 pmp->pm_maxcluster, pmp->pm_fatmask);
732 error = EINVAL;
733 goto error_exit;
734 }
735
736 /* validate FAT size */
737 fatbytes = (pmp->pm_maxcluster+1) * pmp->pm_fatmult / pmp->pm_fatdiv;
738 fatblocksecs = howmany(fatbytes, pmp->pm_BytesPerSec);
739
740 if (pmp->pm_FATsecs < fatblocksecs) {
741 DPRINTF("FATsecs %lu < real %lu\n", pmp->pm_FATsecs,
742 fatblocksecs);
743 error = EINVAL;
744 goto error_exit;
745 }
746
747 if (FAT12(pmp)) {
748 /*
749 * limit block size to what is needed to read a FAT block
750 * to not exceed MAXBSIZE
751 */
752 pmp->pm_fatblocksec = uimin(3, fatblocksecs);
753 pmp->pm_fatblocksize = pmp->pm_fatblocksec
754 * pmp->pm_BytesPerSec;
755 } else {
756 pmp->pm_fatblocksize = MAXBSIZE;
757 pmp->pm_fatblocksec = pmp->pm_fatblocksize
758 / pmp->pm_BytesPerSec;
759 }
760
761 pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
762
763 /*
764 * Compute mask and shift value for isolating cluster relative byte
765 * offsets and cluster numbers from a file offset.
766 */
767 pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
768 pmp->pm_crbomask = pmp->pm_bpcluster - 1;
769 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
770
771 /*
772 * Check for valid cluster size
773 * must be a power of 2
774 */
775 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
776 DPRINTF("bpcluster %lu cnshift %lu", pmp->pm_bpcluster,
777 pmp->pm_cnshift);
778 error = EINVAL;
779 goto error_exit;
780 }
781
782 /*
783 * Cluster size must be within limit of MAXBSIZE.
784 * Many FAT filesystems will not have clusters larger than
785 * 32KiB due to limits in Windows versions before Vista.
786 */
787 if (pmp->pm_bpcluster > MAXBSIZE) {
788 DPRINTF("bpcluster %lu > MAXBSIZE %d",
789 pmp->pm_bpcluster, MAXBSIZE);
790 error = EINVAL;
791 goto error_exit;
792 }
793
794 /*
795 * Release the bootsector buffer.
796 */
797 brelse(bp, BC_AGE);
798 bp = NULL;
799
800 /*
801 * Check FSInfo.
802 */
803 if (pmp->pm_fsinfo) {
804 struct fsinfo *fp;
805 const int rdsz = roundup(sizeof(*fp), pmp->pm_BytesPerSec);
806
807 /*
808 * XXX If the fsinfo block is stored on media with
809 * 2KB or larger sectors, is the fsinfo structure
810 * padded at the end or in the middle?
811 */
812 if ((error = bread(devvp, de_bn2kb(pmp, pmp->pm_fsinfo),
813 rdsz, 0, &bp)) != 0)
814 goto error_exit;
815 fp = (struct fsinfo *)bp->b_data;
816 if (!memcmp(fp->fsisig1, "RRaA", 4)
817 && !memcmp(fp->fsisig2, "rrAa", 4)
818 && !memcmp(fp->fsisig3, "\0\0\125\252", 4)
819 && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
820 pmp->pm_nxtfree = getulong(fp->fsinxtfree);
821 else
822 pmp->pm_fsinfo = 0;
823 brelse(bp, 0);
824 bp = NULL;
825 }
826
827 /*
828 * Check and validate (or perhaps invalidate?) the fsinfo structure?
829 * XXX
830 */
831 if (pmp->pm_fsinfo) {
832 if ((pmp->pm_nxtfree == 0xffffffffUL) ||
833 (pmp->pm_nxtfree > pmp->pm_maxcluster))
834 pmp->pm_fsinfo = 0;
835 }
836
837 /*
838 * Allocate memory for the bitmap of allocated clusters, and then
839 * fill it in.
840 */
841 pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS)
842 / N_INUSEBITS)
843 * sizeof(*pmp->pm_inusemap),
844 M_MSDOSFSFAT, M_WAITOK);
845
846 /*
847 * fillinusemap() needs pm_devvp.
848 */
849 pmp->pm_dev = dev;
850 pmp->pm_devvp = devvp;
851
852 /*
853 * Have the inuse map filled in.
854 */
855 if ((error = msdosfs_fillinusemap(pmp)) != 0) {
856 DPRINTF("fillinusemap %d", error);
857 goto error_exit;
858 }
859
860 /*
861 * If they want FAT updates to be synchronous then let them suffer
862 * the performance degradation in exchange for the on disk copy of
863 * the FAT being correct just about all the time. I suppose this
864 * would be a good thing to turn on if the kernel is still flakey.
865 */
866 if (mp->mnt_flag & MNT_SYNCHRONOUS)
867 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
868
869 /*
870 * Finish up.
871 */
872 if (ronly)
873 pmp->pm_flags |= MSDOSFSMNT_RONLY;
874 else
875 pmp->pm_fmod = 1;
876 mp->mnt_data = pmp;
877 mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
878 mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_MSDOS);
879 mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
880 mp->mnt_stat.f_namemax = MSDOSFS_NAMEMAX(pmp);
881 mp->mnt_flag |= MNT_LOCAL;
882 mp->mnt_iflag |= IMNT_SHRLOOKUP;
883 mp->mnt_dev_bshift = pmp->pm_bnshift;
884 mp->mnt_fs_bshift = pmp->pm_cnshift;
885
886 /*
887 * If we ever do quotas for DOS filesystems this would be a place
888 * to fill in the info in the msdosfsmount structure. You dolt,
889 * quotas on dos filesystems make no sense because files have no
890 * owners on dos filesystems. of course there is some empty space
891 * in the directory entry where we could put uid's and gid's.
892 */
893
894 spec_node_setmountedfs(devvp, mp);
895
896 return (0);
897
898 error_exit:
899 if (bp)
900 brelse(bp, BC_AGE);
901 if (pmp) {
902 if (pmp->pm_inusemap)
903 free(pmp->pm_inusemap, M_MSDOSFSFAT);
904 free(pmp, M_MSDOSFSMNT);
905 mp->mnt_data = NULL;
906 }
907 return (error);
908 }
909
910 int
msdosfs_start(struct mount * mp,int flags)911 msdosfs_start(struct mount *mp, int flags)
912 {
913
914 return (0);
915 }
916
917 /*
918 * Unmount the filesystem described by mp.
919 */
920 int
msdosfs_unmount(struct mount * mp,int mntflags)921 msdosfs_unmount(struct mount *mp, int mntflags)
922 {
923 struct msdosfsmount *pmp;
924 int error, flags;
925
926 flags = 0;
927 if (mntflags & MNT_FORCE)
928 flags |= FORCECLOSE;
929 if ((error = vflush(mp, NULLVP, flags)) != 0)
930 return (error);
931 pmp = VFSTOMSDOSFS(mp);
932 if (pmp->pm_devvp->v_type != VBAD)
933 spec_node_setmountedfs(pmp->pm_devvp, NULL);
934 #ifdef MSDOSFS_DEBUG
935 {
936 struct vnode *vp = pmp->pm_devvp;
937
938 printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
939 printf("flag %08x, usecount %d, writecount %d, holdcnt %d\n",
940 vp->v_vflag | vp->v_iflag | vp->v_uflag, vrefcnt(vp),
941 vp->v_writecount, vp->v_holdcnt);
942 printf("mount %p, op %p\n",
943 vp->v_mount, vp->v_op);
944 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
945 vp->v_cleanblkhd.lh_first,
946 vp->v_dirtyblkhd.lh_first,
947 vp->v_numoutput, vp->v_type);
948 printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
949 vp->v_socket, vp->v_tag,
950 ((u_int *)vp->v_data)[0],
951 ((u_int *)vp->v_data)[1]);
952 }
953 #endif
954 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
955 (void) VOP_CLOSE(pmp->pm_devvp,
956 pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED);
957 vput(pmp->pm_devvp);
958 msdosfs_fh_destroy(pmp);
959 free(pmp->pm_inusemap, M_MSDOSFSFAT);
960 free(pmp, M_MSDOSFSMNT);
961 mp->mnt_data = NULL;
962 mp->mnt_flag &= ~MNT_LOCAL;
963 return (0);
964 }
965
966 int
msdosfs_root(struct mount * mp,int lktype,struct vnode ** vpp)967 msdosfs_root(struct mount *mp, int lktype, struct vnode **vpp)
968 {
969 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
970 int error;
971
972 #ifdef MSDOSFS_DEBUG
973 printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
974 #endif
975 if ((error = msdosfs_deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS,
976 vpp)) != 0)
977 return error;
978 error = vn_lock(*vpp, lktype);
979 if (error) {
980 vrele(*vpp);
981 *vpp = NULL;
982 return error;
983 }
984 return 0;
985 }
986
987 int
msdosfs_statvfs(struct mount * mp,struct statvfs * sbp)988 msdosfs_statvfs(struct mount *mp, struct statvfs *sbp)
989 {
990 struct msdosfsmount *pmp;
991
992 pmp = VFSTOMSDOSFS(mp);
993 sbp->f_bsize = pmp->pm_bpcluster;
994 sbp->f_frsize = sbp->f_bsize;
995 sbp->f_iosize = pmp->pm_bpcluster;
996 sbp->f_blocks = pmp->pm_nmbrofclusters;
997 sbp->f_bfree = pmp->pm_freeclustercount;
998 sbp->f_bavail = pmp->pm_freeclustercount;
999 sbp->f_bresvd = 0;
1000 sbp->f_files = pmp->pm_RootDirEnts; /* XXX */
1001 sbp->f_ffree = 0; /* what to put in here? */
1002 sbp->f_favail = 0; /* what to put in here? */
1003 sbp->f_fresvd = 0;
1004 copy_statvfs_info(sbp, mp);
1005 return (0);
1006 }
1007
1008 struct msdosfs_sync_ctx {
1009 int waitfor;
1010 };
1011
1012 static bool
msdosfs_sync_selector(void * cl,struct vnode * vp)1013 msdosfs_sync_selector(void *cl, struct vnode *vp)
1014 {
1015 struct msdosfs_sync_ctx *c = cl;
1016 struct denode *dep;
1017
1018 KASSERT(mutex_owned(vp->v_interlock));
1019
1020 dep = VTODE(vp);
1021 if (c->waitfor == MNT_LAZY || vp->v_type == VNON ||
1022 dep == NULL || (((dep->de_flag &
1023 (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
1024 (LIST_EMPTY(&vp->v_dirtyblkhd) &&
1025 (vp->v_iflag & VI_ONWORKLST) == 0)))
1026 return false;
1027 return true;
1028 }
1029
1030 int
msdosfs_sync(struct mount * mp,int waitfor,kauth_cred_t cred)1031 msdosfs_sync(struct mount *mp, int waitfor, kauth_cred_t cred)
1032 {
1033 struct vnode *vp;
1034 struct vnode_iterator *marker;
1035 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
1036 int error, allerror = 0;
1037 struct msdosfs_sync_ctx ctx;
1038
1039 /*
1040 * If we ever switch to not updating all of the FATs all the time,
1041 * this would be the place to update them from the first one.
1042 */
1043 if (pmp->pm_fmod != 0) {
1044 if (pmp->pm_flags & MSDOSFSMNT_RONLY)
1045 panic("msdosfs_sync: rofs mod");
1046 else {
1047 /* update FATs here */
1048 }
1049 }
1050 /*
1051 * Write back each (modified) denode.
1052 */
1053 vfs_vnode_iterator_init(mp, &marker);
1054 ctx.waitfor = waitfor;
1055 while ((vp = vfs_vnode_iterator_next(marker, msdosfs_sync_selector,
1056 &ctx)))
1057 {
1058 error = vn_lock(vp, LK_EXCLUSIVE);
1059 if (error) {
1060 vrele(vp);
1061 continue;
1062 }
1063 if ((error = VOP_FSYNC(vp, cred,
1064 waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
1065 allerror = error;
1066 vput(vp);
1067 }
1068 vfs_vnode_iterator_destroy(marker);
1069
1070 /*
1071 * Force stale file system control information to be flushed.
1072 */
1073 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
1074 if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
1075 waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0)) != 0)
1076 allerror = error;
1077 VOP_UNLOCK(pmp->pm_devvp);
1078 return (allerror);
1079 }
1080
1081 int
msdosfs_fhtovp(struct mount * mp,struct fid * fhp,int lktype,struct vnode ** vpp)1082 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, int lktype, struct vnode **vpp)
1083 {
1084 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
1085 struct defid defh;
1086 uint32_t gen;
1087 int error;
1088
1089 if (fhp->fid_len != sizeof(struct defid)) {
1090 DPRINTF("fid_len %d %zd", fhp->fid_len, sizeof(struct defid));
1091 return EINVAL;
1092 }
1093 memcpy(&defh, fhp, sizeof(defh));
1094 error = msdosfs_fh_lookup(pmp, defh.defid_dirclust, defh.defid_dirofs,
1095 &gen);
1096 if (error == 0 && gen != defh.defid_gen)
1097 error = ESTALE;
1098 if (error) {
1099 *vpp = NULLVP;
1100 return error;
1101 }
1102 error = msdosfs_deget(pmp, defh.defid_dirclust, defh.defid_dirofs, vpp);
1103 if (error) {
1104 DPRINTF("deget %d", error);
1105 *vpp = NULLVP;
1106 return error;
1107 }
1108 error = vn_lock(*vpp, lktype);
1109 if (error) {
1110 vrele(*vpp);
1111 *vpp = NULLVP;
1112 return error;
1113 }
1114 return 0;
1115 }
1116
1117 int
msdosfs_vptofh(struct vnode * vp,struct fid * fhp,size_t * fh_size)1118 msdosfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
1119 {
1120 struct msdosfsmount *pmp = VFSTOMSDOSFS(vp->v_mount);
1121 struct denode *dep;
1122 struct defid defh;
1123 int error;
1124
1125 if (*fh_size < sizeof(struct defid)) {
1126 *fh_size = sizeof(struct defid);
1127 return E2BIG;
1128 }
1129 *fh_size = sizeof(struct defid);
1130 dep = VTODE(vp);
1131 memset(&defh, 0, sizeof(defh));
1132 defh.defid_len = sizeof(struct defid);
1133 defh.defid_dirclust = dep->de_dirclust;
1134 defh.defid_dirofs = dep->de_diroffset;
1135 error = msdosfs_fh_enter(pmp, dep->de_dirclust, dep->de_diroffset,
1136 &defh.defid_gen);
1137 if (error == 0)
1138 memcpy(fhp, &defh, sizeof(defh));
1139 return error;
1140 }
1141
1142 int
msdosfs_vget(struct mount * mp,ino_t ino,int lktype,struct vnode ** vpp)1143 msdosfs_vget(struct mount *mp, ino_t ino, int lktype,
1144 struct vnode **vpp)
1145 {
1146
1147 return (EOPNOTSUPP);
1148 }
1149