1 /* $FreeBSD: stable/10/sys/fs/msdosfs/msdosfs_vfsops.c 308552 2016-11-11 20:08:45Z kib $ */
2 /* $NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws Exp $ */
3
4 /*-
5 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
6 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7 * All rights reserved.
8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by TooLs GmbH.
21 * 4. The name of TooLs GmbH may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35 /*-
36 * Written by Paul Popelka (paulp@uts.amdahl.com)
37 *
38 * You can do anything you want with this software, just don't say you wrote
39 * it, and don't remove this notice.
40 *
41 * This software is provided "as is".
42 *
43 * The author supplies this software to be publicly redistributed on the
44 * understanding that the author is not responsible for the correct
45 * functioning of this software in any circumstances and is not liable for
46 * any damages caused by this software.
47 *
48 * October 1992
49 */
50
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/buf.h>
54 #include <sys/conf.h>
55 #include <sys/fcntl.h>
56 #include <sys/iconv.h>
57 #include <sys/kernel.h>
58 #include <sys/lock.h>
59 #include <sys/malloc.h>
60 #include <sys/mount.h>
61 #include <sys/mutex.h>
62 #include <sys/namei.h>
63 #include <sys/priv.h>
64 #include <sys/proc.h>
65 #include <sys/stat.h>
66 #include <sys/vnode.h>
67
68 #include <geom/geom.h>
69 #include <geom/geom_vfs.h>
70
71 #include <fs/msdosfs/bootsect.h>
72 #include <fs/msdosfs/bpb.h>
73 #include <fs/msdosfs/direntry.h>
74 #include <fs/msdosfs/denode.h>
75 #include <fs/msdosfs/fat.h>
76 #include <fs/msdosfs/msdosfsmount.h>
77
78 static const char msdosfs_lock_msg[] = "fatlk";
79
80 /* Mount options that we support. */
81 static const char *msdosfs_opts[] = {
82 "async", "noatime", "noclusterr", "noclusterw",
83 "export", "force", "from", "sync",
84 "cs_dos", "cs_local", "cs_win", "dirmask",
85 "gid", "kiconv", "large", "longname",
86 "longnames", "mask", "shortname", "shortnames",
87 "uid", "win95", "nowin95",
88 NULL
89 };
90
91 #if 1 /*def PC98*/
92 /*
93 * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
94 * garbage or a random value :-{
95 * If you want to use that broken-signatured media, define the
96 * following symbol even though PC/AT.
97 * (ex. mount PC-98 DOS formatted FD on PC/AT)
98 */
99 #define MSDOSFS_NOCHECKSIG
100 #endif
101
102 MALLOC_DEFINE(M_MSDOSFSMNT, "msdosfs_mount", "MSDOSFS mount structure");
103 static MALLOC_DEFINE(M_MSDOSFSFAT, "msdosfs_fat", "MSDOSFS file allocation table");
104
105 struct iconv_functions *msdosfs_iconv;
106
107 static int update_mp(struct mount *mp, struct thread *td);
108 static int mountmsdosfs(struct vnode *devvp, struct mount *mp);
109 static vfs_fhtovp_t msdosfs_fhtovp;
110 static vfs_mount_t msdosfs_mount;
111 static vfs_root_t msdosfs_root;
112 static vfs_statfs_t msdosfs_statfs;
113 static vfs_sync_t msdosfs_sync;
114 static vfs_unmount_t msdosfs_unmount;
115
116 /* Maximum length of a character set name (arbitrary). */
117 #define MAXCSLEN 64
118
119 static int
update_mp(struct mount * mp,struct thread * td)120 update_mp(struct mount *mp, struct thread *td)
121 {
122 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
123 void *dos, *win, *local;
124 int error, v;
125
126 if (!vfs_getopt(mp->mnt_optnew, "kiconv", NULL, NULL)) {
127 if (msdosfs_iconv != NULL) {
128 error = vfs_getopt(mp->mnt_optnew,
129 "cs_win", &win, NULL);
130 if (!error)
131 error = vfs_getopt(mp->mnt_optnew,
132 "cs_local", &local, NULL);
133 if (!error)
134 error = vfs_getopt(mp->mnt_optnew,
135 "cs_dos", &dos, NULL);
136 if (!error) {
137 msdosfs_iconv->open(win, local, &pmp->pm_u2w);
138 msdosfs_iconv->open(local, win, &pmp->pm_w2u);
139 msdosfs_iconv->open(dos, local, &pmp->pm_u2d);
140 msdosfs_iconv->open(local, dos, &pmp->pm_d2u);
141 }
142 if (error != 0)
143 return (error);
144 } else {
145 pmp->pm_w2u = NULL;
146 pmp->pm_u2w = NULL;
147 pmp->pm_d2u = NULL;
148 pmp->pm_u2d = NULL;
149 }
150 }
151
152 if (vfs_scanopt(mp->mnt_optnew, "gid", "%d", &v) == 1)
153 pmp->pm_gid = v;
154 if (vfs_scanopt(mp->mnt_optnew, "uid", "%d", &v) == 1)
155 pmp->pm_uid = v;
156 if (vfs_scanopt(mp->mnt_optnew, "mask", "%d", &v) == 1)
157 pmp->pm_mask = v & ALLPERMS;
158 if (vfs_scanopt(mp->mnt_optnew, "dirmask", "%d", &v) == 1)
159 pmp->pm_dirmask = v & ALLPERMS;
160 vfs_flagopt(mp->mnt_optnew, "shortname",
161 &pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
162 vfs_flagopt(mp->mnt_optnew, "shortnames",
163 &pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
164 vfs_flagopt(mp->mnt_optnew, "longname",
165 &pmp->pm_flags, MSDOSFSMNT_LONGNAME);
166 vfs_flagopt(mp->mnt_optnew, "longnames",
167 &pmp->pm_flags, MSDOSFSMNT_LONGNAME);
168 vfs_flagopt(mp->mnt_optnew, "kiconv",
169 &pmp->pm_flags, MSDOSFSMNT_KICONV);
170
171 if (vfs_getopt(mp->mnt_optnew, "nowin95", NULL, NULL) == 0)
172 pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
173 else
174 pmp->pm_flags &= ~MSDOSFSMNT_NOWIN95;
175
176 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
177 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
178 else
179 pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
180 return 0;
181 }
182
183 static int
msdosfs_cmount(struct mntarg * ma,void * data,uint64_t flags)184 msdosfs_cmount(struct mntarg *ma, void *data, uint64_t flags)
185 {
186 struct msdosfs_args args;
187 struct export_args exp;
188 int error;
189
190 if (data == NULL)
191 return (EINVAL);
192 error = copyin(data, &args, sizeof args);
193 if (error)
194 return (error);
195 vfs_oexport_conv(&args.export, &exp);
196
197 ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
198 ma = mount_arg(ma, "export", &exp, sizeof(exp));
199 ma = mount_argf(ma, "uid", "%d", args.uid);
200 ma = mount_argf(ma, "gid", "%d", args.gid);
201 ma = mount_argf(ma, "mask", "%d", args.mask);
202 ma = mount_argf(ma, "dirmask", "%d", args.dirmask);
203
204 ma = mount_argb(ma, args.flags & MSDOSFSMNT_SHORTNAME, "noshortname");
205 ma = mount_argb(ma, args.flags & MSDOSFSMNT_LONGNAME, "nolongname");
206 ma = mount_argb(ma, !(args.flags & MSDOSFSMNT_NOWIN95), "nowin95");
207 ma = mount_argb(ma, args.flags & MSDOSFSMNT_KICONV, "nokiconv");
208
209 ma = mount_argsu(ma, "cs_win", args.cs_win, MAXCSLEN);
210 ma = mount_argsu(ma, "cs_dos", args.cs_dos, MAXCSLEN);
211 ma = mount_argsu(ma, "cs_local", args.cs_local, MAXCSLEN);
212
213 error = kernel_mount(ma, flags);
214
215 return (error);
216 }
217
218 /*
219 * mp - path - addr in user space of mount point (ie /usr or whatever)
220 * data - addr in user space of mount params including the name of the block
221 * special file to treat as a filesystem.
222 */
223 static int
msdosfs_mount(struct mount * mp)224 msdosfs_mount(struct mount *mp)
225 {
226 struct vnode *devvp; /* vnode for blk device to mount */
227 struct thread *td;
228 /* msdosfs specific mount control block */
229 struct msdosfsmount *pmp = NULL;
230 struct nameidata ndp;
231 int error, flags;
232 accmode_t accmode;
233 char *from;
234
235 td = curthread;
236 if (vfs_filteropt(mp->mnt_optnew, msdosfs_opts))
237 return (EINVAL);
238
239 /*
240 * If updating, check whether changing from read-only to
241 * read/write; if there is no device name, that's all we do.
242 */
243 if (mp->mnt_flag & MNT_UPDATE) {
244 pmp = VFSTOMSDOSFS(mp);
245 if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0)) {
246 /*
247 * Forbid export requests if filesystem has
248 * MSDOSFS_LARGEFS flag set.
249 */
250 if ((pmp->pm_flags & MSDOSFS_LARGEFS) != 0) {
251 vfs_mount_error(mp,
252 "MSDOSFS_LARGEFS flag set, cannot export");
253 return (EOPNOTSUPP);
254 }
255 }
256 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
257 vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
258 error = VFS_SYNC(mp, MNT_WAIT);
259 if (error)
260 return (error);
261 flags = WRITECLOSE;
262 if (mp->mnt_flag & MNT_FORCE)
263 flags |= FORCECLOSE;
264 error = vflush(mp, 0, flags, td);
265 if (error)
266 return (error);
267
268 /*
269 * Now the volume is clean. Mark it so while the
270 * device is still rw.
271 */
272 error = markvoldirty(pmp, 0);
273 if (error) {
274 (void)markvoldirty(pmp, 1);
275 return (error);
276 }
277
278 /* Downgrade the device from rw to ro. */
279 DROP_GIANT();
280 g_topology_lock();
281 error = g_access(pmp->pm_cp, 0, -1, 0);
282 g_topology_unlock();
283 PICKUP_GIANT();
284 if (error) {
285 (void)markvoldirty(pmp, 1);
286 return (error);
287 }
288
289 /*
290 * Backing out after an error was painful in the
291 * above. Now we are committed to succeeding.
292 */
293 pmp->pm_fmod = 0;
294 pmp->pm_flags |= MSDOSFSMNT_RONLY;
295 MNT_ILOCK(mp);
296 mp->mnt_flag |= MNT_RDONLY;
297 MNT_IUNLOCK(mp);
298 } else if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
299 !vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
300 /*
301 * If upgrade to read-write by non-root, then verify
302 * that user has necessary permissions on the device.
303 */
304 devvp = pmp->pm_devvp;
305 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
306 error = VOP_ACCESS(devvp, VREAD | VWRITE,
307 td->td_ucred, td);
308 if (error)
309 error = priv_check(td, PRIV_VFS_MOUNT_PERM);
310 if (error) {
311 VOP_UNLOCK(devvp, 0);
312 return (error);
313 }
314 VOP_UNLOCK(devvp, 0);
315 DROP_GIANT();
316 g_topology_lock();
317 error = g_access(pmp->pm_cp, 0, 1, 0);
318 g_topology_unlock();
319 PICKUP_GIANT();
320 if (error)
321 return (error);
322
323 pmp->pm_fmod = 1;
324 pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
325 MNT_ILOCK(mp);
326 mp->mnt_flag &= ~MNT_RDONLY;
327 MNT_IUNLOCK(mp);
328
329 /* Now that the volume is modifiable, mark it dirty. */
330 error = markvoldirty(pmp, 1);
331 if (error)
332 return (error);
333 }
334 }
335 /*
336 * Not an update, or updating the name: look up the name
337 * and verify that it refers to a sensible disk device.
338 */
339 if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
340 return (EINVAL);
341 NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, from, td);
342 error = namei(&ndp);
343 if (error)
344 return (error);
345 devvp = ndp.ni_vp;
346 NDFREE(&ndp, NDF_ONLY_PNBUF);
347
348 if (!vn_isdisk(devvp, &error)) {
349 vput(devvp);
350 return (error);
351 }
352 /*
353 * If mount by non-root, then verify that user has necessary
354 * permissions on the device.
355 */
356 accmode = VREAD;
357 if ((mp->mnt_flag & MNT_RDONLY) == 0)
358 accmode |= VWRITE;
359 error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
360 if (error)
361 error = priv_check(td, PRIV_VFS_MOUNT_PERM);
362 if (error) {
363 vput(devvp);
364 return (error);
365 }
366 if ((mp->mnt_flag & MNT_UPDATE) == 0) {
367 error = mountmsdosfs(devvp, mp);
368 #ifdef MSDOSFS_DEBUG /* only needed for the printf below */
369 pmp = VFSTOMSDOSFS(mp);
370 #endif
371 } else {
372 vput(devvp);
373 if (devvp != pmp->pm_devvp)
374 return (EINVAL); /* XXX needs translation */
375 }
376 if (error) {
377 vrele(devvp);
378 return (error);
379 }
380
381 error = update_mp(mp, td);
382 if (error) {
383 if ((mp->mnt_flag & MNT_UPDATE) == 0)
384 msdosfs_unmount(mp, MNT_FORCE);
385 return error;
386 }
387
388 if (devvp->v_type == VCHR && devvp->v_rdev != NULL)
389 devvp->v_rdev->si_mountpt = mp;
390 vfs_mountedfrom(mp, from);
391 #ifdef MSDOSFS_DEBUG
392 printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
393 #endif
394 return (0);
395 }
396
397 static int
mountmsdosfs(struct vnode * devvp,struct mount * mp)398 mountmsdosfs(struct vnode *devvp, struct mount *mp)
399 {
400 struct msdosfsmount *pmp;
401 struct buf *bp;
402 struct cdev *dev;
403 union bootsector *bsp;
404 struct byte_bpb33 *b33;
405 struct byte_bpb50 *b50;
406 struct byte_bpb710 *b710;
407 u_int8_t SecPerClust;
408 u_long clusters;
409 int ronly, error;
410 struct g_consumer *cp;
411 struct bufobj *bo;
412
413 bp = NULL; /* This and pmp both used in error_exit. */
414 pmp = NULL;
415 ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
416
417 dev = devvp->v_rdev;
418 dev_ref(dev);
419 DROP_GIANT();
420 g_topology_lock();
421 error = g_vfs_open(devvp, &cp, "msdosfs", ronly ? 0 : 1);
422 g_topology_unlock();
423 PICKUP_GIANT();
424 VOP_UNLOCK(devvp, 0);
425 if (error)
426 goto error_exit;
427
428 bo = &devvp->v_bufobj;
429
430 /*
431 * Read the boot sector of the filesystem, and then check the
432 * boot signature. If not a dos boot sector then error out.
433 *
434 * NOTE: 8192 is a magic size that works for ffs.
435 */
436 error = bread(devvp, 0, 8192, NOCRED, &bp);
437 if (error)
438 goto error_exit;
439 bp->b_flags |= B_AGE;
440 bsp = (union bootsector *)bp->b_data;
441 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
442 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
443 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
444
445 #ifndef MSDOSFS_NOCHECKSIG
446 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
447 || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
448 error = EINVAL;
449 goto error_exit;
450 }
451 #endif
452
453 pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
454 pmp->pm_mountp = mp;
455 pmp->pm_cp = cp;
456 pmp->pm_bo = bo;
457
458 lockinit(&pmp->pm_fatlock, 0, msdosfs_lock_msg, 0, 0);
459
460 /*
461 * Initialize ownerships and permissions, since nothing else will
462 * initialize them iff we are mounting root.
463 */
464 pmp->pm_uid = UID_ROOT;
465 pmp->pm_gid = GID_WHEEL;
466 pmp->pm_mask = pmp->pm_dirmask = S_IXUSR | S_IXGRP | S_IXOTH |
467 S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR;
468
469 /*
470 * Experimental support for large MS-DOS filesystems.
471 * WARNING: This uses at least 32 bytes of kernel memory (which is not
472 * reclaimed until the FS is unmounted) for each file on disk to map
473 * between the 32-bit inode numbers used by VFS and the 64-bit
474 * pseudo-inode numbers used internally by msdosfs. This is only
475 * safe to use in certain controlled situations (e.g. read-only FS
476 * with less than 1 million files).
477 * Since the mappings do not persist across unmounts (or reboots), these
478 * filesystems are not suitable for exporting through NFS, or any other
479 * application that requires fixed inode numbers.
480 */
481 vfs_flagopt(mp->mnt_optnew, "large", &pmp->pm_flags, MSDOSFS_LARGEFS);
482
483 /*
484 * Compute several useful quantities from the bpb in the
485 * bootsector. Copy in the dos 5 variant of the bpb then fix up
486 * the fields that are different between dos 5 and dos 3.3.
487 */
488 SecPerClust = b50->bpbSecPerClust;
489 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
490 if (pmp->pm_BytesPerSec < DEV_BSIZE) {
491 error = EINVAL;
492 goto error_exit;
493 }
494 pmp->pm_ResSectors = getushort(b50->bpbResSectors);
495 pmp->pm_FATs = b50->bpbFATs;
496 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
497 pmp->pm_Sectors = getushort(b50->bpbSectors);
498 pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
499 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
500 pmp->pm_Heads = getushort(b50->bpbHeads);
501 pmp->pm_Media = b50->bpbMedia;
502
503 /* calculate the ratio of sector size to DEV_BSIZE */
504 pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
505
506 /*
507 * We don't check pm_Heads nor pm_SecPerTrack, because
508 * these may not be set for EFI file systems. We don't
509 * use these anyway, so we're unaffected if they are
510 * invalid.
511 */
512 if (!pmp->pm_BytesPerSec || !SecPerClust) {
513 error = EINVAL;
514 goto error_exit;
515 }
516
517 if (pmp->pm_Sectors == 0) {
518 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
519 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
520 } else {
521 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
522 pmp->pm_HugeSectors = pmp->pm_Sectors;
523 }
524 if (!(pmp->pm_flags & MSDOSFS_LARGEFS)) {
525 if (pmp->pm_HugeSectors > 0xffffffff /
526 (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
527 /*
528 * We cannot deal currently with this size of disk
529 * due to fileid limitations (see msdosfs_getattr and
530 * msdosfs_readdir)
531 */
532 error = EINVAL;
533 vfs_mount_error(mp,
534 "Disk too big, try '-o large' mount option");
535 goto error_exit;
536 }
537 }
538
539 if (pmp->pm_RootDirEnts == 0) {
540 if (pmp->pm_FATsecs
541 || getushort(b710->bpbFSVers)) {
542 error = EINVAL;
543 #ifdef MSDOSFS_DEBUG
544 printf("mountmsdosfs(): bad FAT32 filesystem\n");
545 #endif
546 goto error_exit;
547 }
548 pmp->pm_fatmask = FAT32_MASK;
549 pmp->pm_fatmult = 4;
550 pmp->pm_fatdiv = 1;
551 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
552 if (getushort(b710->bpbExtFlags) & FATMIRROR)
553 pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
554 else
555 pmp->pm_flags |= MSDOSFS_FATMIRROR;
556 } else
557 pmp->pm_flags |= MSDOSFS_FATMIRROR;
558
559 /*
560 * Check a few values (could do some more):
561 * - logical sector size: power of 2, >= block size
562 * - sectors per cluster: power of 2, >= 1
563 * - number of sectors: >= 1, <= size of partition
564 * - number of FAT sectors: >= 1
565 */
566 if ( (SecPerClust == 0)
567 || (SecPerClust & (SecPerClust - 1))
568 || (pmp->pm_BytesPerSec < DEV_BSIZE)
569 || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
570 || (pmp->pm_HugeSectors == 0)
571 || (pmp->pm_FATsecs == 0)
572 || (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE)
573 ) {
574 error = EINVAL;
575 goto error_exit;
576 }
577
578 pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
579 pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
580 pmp->pm_FATsecs *= pmp->pm_BlkPerSec;
581 SecPerClust *= pmp->pm_BlkPerSec;
582
583 pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
584
585 if (FAT32(pmp)) {
586 pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
587 pmp->pm_firstcluster = pmp->pm_fatblk
588 + (pmp->pm_FATs * pmp->pm_FATsecs);
589 pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
590 } else {
591 pmp->pm_rootdirblk = pmp->pm_fatblk +
592 (pmp->pm_FATs * pmp->pm_FATsecs);
593 pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
594 + DEV_BSIZE - 1)
595 / DEV_BSIZE; /* in blocks */
596 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
597 }
598
599 pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
600 SecPerClust + 1;
601 pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
602
603 if (pmp->pm_fatmask == 0) {
604 if (pmp->pm_maxcluster
605 <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
606 /*
607 * This will usually be a floppy disk. This size makes
608 * sure that one fat entry will not be split across
609 * multiple blocks.
610 */
611 pmp->pm_fatmask = FAT12_MASK;
612 pmp->pm_fatmult = 3;
613 pmp->pm_fatdiv = 2;
614 } else {
615 pmp->pm_fatmask = FAT16_MASK;
616 pmp->pm_fatmult = 2;
617 pmp->pm_fatdiv = 1;
618 }
619 }
620
621 clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
622 if (pmp->pm_maxcluster >= clusters) {
623 #ifdef MSDOSFS_DEBUG
624 printf("Warning: number of clusters (%ld) exceeds FAT "
625 "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
626 #endif
627 pmp->pm_maxcluster = clusters - 1;
628 }
629
630 if (FAT12(pmp))
631 pmp->pm_fatblocksize = 3 * 512;
632 else
633 pmp->pm_fatblocksize = PAGE_SIZE;
634 pmp->pm_fatblocksize = roundup(pmp->pm_fatblocksize,
635 pmp->pm_BytesPerSec);
636 pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
637 pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
638
639 /*
640 * Compute mask and shift value for isolating cluster relative byte
641 * offsets and cluster numbers from a file offset.
642 */
643 pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
644 pmp->pm_crbomask = pmp->pm_bpcluster - 1;
645 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
646
647 /*
648 * Check for valid cluster size
649 * must be a power of 2
650 */
651 if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
652 error = EINVAL;
653 goto error_exit;
654 }
655
656 /*
657 * Release the bootsector buffer.
658 */
659 brelse(bp);
660 bp = NULL;
661
662 /*
663 * Check the fsinfo sector if we have one. Silently fix up our
664 * in-core copy of fp->fsinxtfree if it is unknown (0xffffffff)
665 * or too large. Ignore fp->fsinfree for now, since we need to
666 * read the entire FAT anyway to fill the inuse map.
667 */
668 if (pmp->pm_fsinfo) {
669 struct fsinfo *fp;
670
671 if ((error = bread(devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec,
672 NOCRED, &bp)) != 0)
673 goto error_exit;
674 fp = (struct fsinfo *)bp->b_data;
675 if (!bcmp(fp->fsisig1, "RRaA", 4)
676 && !bcmp(fp->fsisig2, "rrAa", 4)
677 && !bcmp(fp->fsisig3, "\0\0\125\252", 4)) {
678 pmp->pm_nxtfree = getulong(fp->fsinxtfree);
679 if (pmp->pm_nxtfree > pmp->pm_maxcluster)
680 pmp->pm_nxtfree = CLUST_FIRST;
681 } else
682 pmp->pm_fsinfo = 0;
683 brelse(bp);
684 bp = NULL;
685 }
686
687 /*
688 * Finish initializing pmp->pm_nxtfree (just in case the first few
689 * sectors aren't properly reserved in the FAT). This completes
690 * the fixup for fp->fsinxtfree, and fixes up the zero-initialized
691 * value if there is no fsinfo. We will use pmp->pm_nxtfree
692 * internally even if there is no fsinfo.
693 */
694 if (pmp->pm_nxtfree < CLUST_FIRST)
695 pmp->pm_nxtfree = CLUST_FIRST;
696
697 /*
698 * Allocate memory for the bitmap of allocated clusters, and then
699 * fill it in.
700 */
701 pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS)
702 * sizeof(*pmp->pm_inusemap),
703 M_MSDOSFSFAT, M_WAITOK);
704
705 /*
706 * fillinusemap() needs pm_devvp.
707 */
708 pmp->pm_devvp = devvp;
709 pmp->pm_dev = dev;
710
711 /*
712 * Have the inuse map filled in.
713 */
714 MSDOSFS_LOCK_MP(pmp);
715 error = fillinusemap(pmp);
716 MSDOSFS_UNLOCK_MP(pmp);
717 if (error != 0)
718 goto error_exit;
719
720 /*
721 * If they want fat updates to be synchronous then let them suffer
722 * the performance degradation in exchange for the on disk copy of
723 * the fat being correct just about all the time. I suppose this
724 * would be a good thing to turn on if the kernel is still flakey.
725 */
726 if (mp->mnt_flag & MNT_SYNCHRONOUS)
727 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
728
729 /*
730 * Finish up.
731 */
732 if (ronly)
733 pmp->pm_flags |= MSDOSFSMNT_RONLY;
734 else {
735 if ((error = markvoldirty(pmp, 1)) != 0) {
736 (void)markvoldirty(pmp, 0);
737 goto error_exit;
738 }
739 pmp->pm_fmod = 1;
740 }
741 mp->mnt_data = pmp;
742 mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
743 mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
744 MNT_ILOCK(mp);
745 mp->mnt_flag |= MNT_LOCAL;
746 mp->mnt_kern_flag |= MNTK_USES_BCACHE | MNTK_NO_IOPF;
747 MNT_IUNLOCK(mp);
748
749 if (pmp->pm_flags & MSDOSFS_LARGEFS)
750 msdosfs_fileno_init(mp);
751
752 return 0;
753
754 error_exit:
755 if (bp)
756 brelse(bp);
757 if (cp != NULL) {
758 DROP_GIANT();
759 g_topology_lock();
760 g_vfs_close(cp);
761 g_topology_unlock();
762 PICKUP_GIANT();
763 }
764 if (pmp) {
765 lockdestroy(&pmp->pm_fatlock);
766 free(pmp->pm_inusemap, M_MSDOSFSFAT);
767 free(pmp, M_MSDOSFSMNT);
768 mp->mnt_data = NULL;
769 }
770 dev_rel(dev);
771 return (error);
772 }
773
774 /*
775 * Unmount the filesystem described by mp.
776 */
777 static int
msdosfs_unmount(struct mount * mp,int mntflags)778 msdosfs_unmount(struct mount *mp, int mntflags)
779 {
780 struct msdosfsmount *pmp;
781 int error, flags;
782
783 error = flags = 0;
784 pmp = VFSTOMSDOSFS(mp);
785 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) == 0)
786 error = msdosfs_sync(mp, MNT_WAIT);
787 if ((mntflags & MNT_FORCE) != 0)
788 flags |= FORCECLOSE;
789 else if (error != 0)
790 return (error);
791 error = vflush(mp, 0, flags, curthread);
792 if (error != 0 && error != ENXIO)
793 return (error);
794 if ((pmp->pm_flags & MSDOSFSMNT_RONLY) == 0) {
795 error = markvoldirty(pmp, 0);
796 if (error && error != ENXIO) {
797 (void)markvoldirty(pmp, 1);
798 return (error);
799 }
800 }
801 if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
802 if (pmp->pm_w2u)
803 msdosfs_iconv->close(pmp->pm_w2u);
804 if (pmp->pm_u2w)
805 msdosfs_iconv->close(pmp->pm_u2w);
806 if (pmp->pm_d2u)
807 msdosfs_iconv->close(pmp->pm_d2u);
808 if (pmp->pm_u2d)
809 msdosfs_iconv->close(pmp->pm_u2d);
810 }
811
812 #ifdef MSDOSFS_DEBUG
813 {
814 struct vnode *vp = pmp->pm_devvp;
815 struct bufobj *bo;
816
817 bo = &vp->v_bufobj;
818 BO_LOCK(bo);
819 VI_LOCK(vp);
820 vn_printf(vp,
821 "msdosfs_umount(): just before calling VOP_CLOSE()\n");
822 printf("freef %p, freeb %p, mount %p\n",
823 TAILQ_NEXT(vp, v_actfreelist), vp->v_actfreelist.tqe_prev,
824 vp->v_mount);
825 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
826 TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd),
827 TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd),
828 vp->v_bufobj.bo_numoutput, vp->v_type);
829 VI_UNLOCK(vp);
830 BO_UNLOCK(bo);
831 }
832 #endif
833 DROP_GIANT();
834 if (pmp->pm_devvp->v_type == VCHR && pmp->pm_devvp->v_rdev != NULL)
835 pmp->pm_devvp->v_rdev->si_mountpt = NULL;
836 g_topology_lock();
837 g_vfs_close(pmp->pm_cp);
838 g_topology_unlock();
839 PICKUP_GIANT();
840 vrele(pmp->pm_devvp);
841 dev_rel(pmp->pm_dev);
842 free(pmp->pm_inusemap, M_MSDOSFSFAT);
843 if (pmp->pm_flags & MSDOSFS_LARGEFS)
844 msdosfs_fileno_free(mp);
845 lockdestroy(&pmp->pm_fatlock);
846 free(pmp, M_MSDOSFSMNT);
847 mp->mnt_data = NULL;
848 MNT_ILOCK(mp);
849 mp->mnt_flag &= ~MNT_LOCAL;
850 MNT_IUNLOCK(mp);
851 return (error);
852 }
853
854 static int
msdosfs_root(struct mount * mp,int flags,struct vnode ** vpp)855 msdosfs_root(struct mount *mp, int flags, struct vnode **vpp)
856 {
857 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
858 struct denode *ndep;
859 int error;
860
861 #ifdef MSDOSFS_DEBUG
862 printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
863 #endif
864 error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
865 if (error)
866 return (error);
867 *vpp = DETOV(ndep);
868 return (0);
869 }
870
871 static int
msdosfs_statfs(struct mount * mp,struct statfs * sbp)872 msdosfs_statfs(struct mount *mp, struct statfs *sbp)
873 {
874 struct msdosfsmount *pmp;
875
876 pmp = VFSTOMSDOSFS(mp);
877 sbp->f_bsize = pmp->pm_bpcluster;
878 sbp->f_iosize = pmp->pm_bpcluster;
879 sbp->f_blocks = pmp->pm_maxcluster + 1;
880 sbp->f_bfree = pmp->pm_freeclustercount;
881 sbp->f_bavail = pmp->pm_freeclustercount;
882 sbp->f_files = pmp->pm_RootDirEnts; /* XXX */
883 sbp->f_ffree = 0; /* what to put in here? */
884 return (0);
885 }
886
887 /*
888 * If we have an FSInfo block, update it.
889 */
890 static int
msdosfs_fsiflush(struct msdosfsmount * pmp,int waitfor)891 msdosfs_fsiflush(struct msdosfsmount *pmp, int waitfor)
892 {
893 struct fsinfo *fp;
894 struct buf *bp;
895 int error;
896
897 MSDOSFS_LOCK_MP(pmp);
898 if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) {
899 error = 0;
900 goto unlock;
901 }
902 error = bread(pmp->pm_devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec,
903 NOCRED, &bp);
904 if (error != 0) {
905 brelse(bp);
906 goto unlock;
907 }
908 fp = (struct fsinfo *)bp->b_data;
909 putulong(fp->fsinfree, pmp->pm_freeclustercount);
910 putulong(fp->fsinxtfree, pmp->pm_nxtfree);
911 pmp->pm_flags &= ~MSDOSFS_FSIMOD;
912 if (waitfor == MNT_WAIT)
913 error = bwrite(bp);
914 else
915 bawrite(bp);
916 unlock:
917 MSDOSFS_UNLOCK_MP(pmp);
918 return (error);
919 }
920
921 static int
msdosfs_sync(struct mount * mp,int waitfor)922 msdosfs_sync(struct mount *mp, int waitfor)
923 {
924 struct vnode *vp, *nvp;
925 struct thread *td;
926 struct denode *dep;
927 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
928 int error, allerror = 0;
929
930 td = curthread;
931
932 /*
933 * If we ever switch to not updating all of the fats all the time,
934 * this would be the place to update them from the first one.
935 */
936 if (pmp->pm_fmod != 0) {
937 if (pmp->pm_flags & MSDOSFSMNT_RONLY)
938 panic("msdosfs_sync: rofs mod");
939 else {
940 /* update fats here */
941 }
942 }
943 /*
944 * Write back each (modified) denode.
945 */
946 loop:
947 MNT_VNODE_FOREACH_ALL(vp, mp, nvp) {
948 if (vp->v_type == VNON) {
949 VI_UNLOCK(vp);
950 continue;
951 }
952 dep = VTODE(vp);
953 if ((dep->de_flag &
954 (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
955 (vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
956 waitfor == MNT_LAZY)) {
957 VI_UNLOCK(vp);
958 continue;
959 }
960 error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
961 if (error) {
962 if (error == ENOENT)
963 goto loop;
964 continue;
965 }
966 error = VOP_FSYNC(vp, waitfor, td);
967 if (error)
968 allerror = error;
969 VOP_UNLOCK(vp, 0);
970 vrele(vp);
971 }
972
973 /*
974 * Flush filesystem control info.
975 */
976 if (waitfor != MNT_LAZY) {
977 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
978 error = VOP_FSYNC(pmp->pm_devvp, waitfor, td);
979 if (error)
980 allerror = error;
981 VOP_UNLOCK(pmp->pm_devvp, 0);
982 }
983
984 error = msdosfs_fsiflush(pmp, waitfor);
985 if (error != 0)
986 allerror = error;
987 return (allerror);
988 }
989
990 static int
msdosfs_fhtovp(struct mount * mp,struct fid * fhp,int flags,struct vnode ** vpp)991 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
992 {
993 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
994 struct defid *defhp = (struct defid *) fhp;
995 struct denode *dep;
996 int error;
997
998 error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
999 if (error) {
1000 *vpp = NULLVP;
1001 return (error);
1002 }
1003 *vpp = DETOV(dep);
1004 vnode_create_vobject(*vpp, dep->de_FileSize, curthread);
1005 return (0);
1006 }
1007
1008 static struct vfsops msdosfs_vfsops = {
1009 .vfs_fhtovp = msdosfs_fhtovp,
1010 .vfs_mount = msdosfs_mount,
1011 .vfs_cmount = msdosfs_cmount,
1012 .vfs_root = msdosfs_root,
1013 .vfs_statfs = msdosfs_statfs,
1014 .vfs_sync = msdosfs_sync,
1015 .vfs_unmount = msdosfs_unmount,
1016 };
1017
1018 VFS_SET(msdosfs_vfsops, msdosfs, 0);
1019 MODULE_VERSION(msdosfs, 1);
1020