1 /* $FreeBSD$ */
2 /* $NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws Exp $ */
3
4 /*-
5 * SPDX-License-Identifier: BSD-4-Clause
6 *
7 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
8 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
9 * All rights reserved.
10 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by TooLs GmbH.
23 * 4. The name of TooLs GmbH may not be used to endorse or promote products
24 * derived from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
32 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
33 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
34 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
35 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37 /*-
38 * Written by Paul Popelka (paulp@uts.amdahl.com)
39 *
40 * You can do anything you want with this software, just don't say you wrote
41 * it, and don't remove this notice.
42 *
43 * This software is provided "as is".
44 *
45 * The author supplies this software to be publicly redistributed on the
46 * understanding that the author is not responsible for the correct
47 * functioning of this software in any circumstances and is not liable for
48 * any damages caused by this software.
49 *
50 * October 1992
51 */
52
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/buf.h>
56 #include <sys/bufobj.h>
57 #include <sys/conf.h>
58 #include <sys/fcntl.h>
59 #include <sys/iconv.h>
60 #include <sys/kernel.h>
61 #include <sys/lock.h>
62 #include <sys/malloc.h>
63 #include <sys/mount.h>
64 #include <sys/mutex.h>
65 #include <sys/namei.h>
66 #include <sys/priv.h>
67 #include <sys/proc.h>
68 #include <sys/rwlock.h>
69 #include <sys/stat.h>
70 #include <sys/taskqueue.h>
71 #include <sys/vnode.h>
72
73 #include <geom/geom.h>
74 #include <geom/geom_vfs.h>
75
76 #include <fs/msdosfs/bootsect.h>
77 #include <fs/msdosfs/bpb.h>
78 #include <fs/msdosfs/direntry.h>
79 #include <fs/msdosfs/denode.h>
80 #include <fs/msdosfs/fat.h>
81 #include <fs/msdosfs/msdosfsmount.h>
82
83 #ifdef MSDOSFS_DEBUG
84 #include <sys/rwlock.h>
85 #endif
86
87 static const char msdosfs_lock_msg[] = "fatlk";
88
89 /* Mount options that we support. */
90 static const char *msdosfs_opts[] = {
91 "async", "noatime", "noclusterr", "noclusterw",
92 "export", "force", "from", "sync",
93 "cs_dos", "cs_local", "cs_win", "dirmask",
94 "gid", "kiconv", "longname",
95 "longnames", "mask", "shortname", "shortnames",
96 "uid", "win95", "nowin95",
97 NULL
98 };
99
100 #if 1 /*def PC98*/
101 /*
102 * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
103 * garbage or a random value :-{
104 * If you want to use that broken-signatured media, define the
105 * following symbol even though PC/AT.
106 * (ex. mount PC-98 DOS formatted FD on PC/AT)
107 */
108 #define MSDOSFS_NOCHECKSIG
109 #endif
110
111 MALLOC_DEFINE(M_MSDOSFSMNT, "msdosfs_mount", "MSDOSFS mount structure");
112 static MALLOC_DEFINE(M_MSDOSFSFAT, "msdosfs_fat", "MSDOSFS file allocation table");
113
114 struct iconv_functions *msdosfs_iconv;
115
116 static int update_mp(struct mount *mp, struct thread *td);
117 static int mountmsdosfs(struct vnode *devvp, struct mount *mp);
118 static void msdosfs_remount_ro(void *arg, int pending);
119 static vfs_fhtovp_t msdosfs_fhtovp;
120 static vfs_mount_t msdosfs_mount;
121 static vfs_root_t msdosfs_root;
122 static vfs_statfs_t msdosfs_statfs;
123 static vfs_sync_t msdosfs_sync;
124 static vfs_unmount_t msdosfs_unmount;
125
126 /* Maximum length of a character set name (arbitrary). */
127 #define MAXCSLEN 64
128
129 static int
130 update_mp(struct mount *mp, struct thread *td)
131 {
132 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
133 void *dos, *win, *local;
134 int error, v;
135
136 if (!vfs_getopt(mp->mnt_optnew, "kiconv", NULL, NULL)) {
137 if (msdosfs_iconv != NULL) {
138 error = vfs_getopt(mp->mnt_optnew,
139 "cs_win", &win, NULL);
140 if (!error)
141 error = vfs_getopt(mp->mnt_optnew,
142 "cs_local", &local, NULL);
143 if (!error)
144 error = vfs_getopt(mp->mnt_optnew,
145 "cs_dos", &dos, NULL);
146 if (!error) {
147 msdosfs_iconv->open(win, local, &pmp->pm_u2w);
148 msdosfs_iconv->open(local, win, &pmp->pm_w2u);
149 msdosfs_iconv->open(dos, local, &pmp->pm_u2d);
150 msdosfs_iconv->open(local, dos, &pmp->pm_d2u);
151 }
152 if (error != 0)
153 return (error);
154 } else {
155 pmp->pm_w2u = NULL;
156 pmp->pm_u2w = NULL;
157 pmp->pm_d2u = NULL;
158 pmp->pm_u2d = NULL;
159 }
160 }
161
162 if (vfs_scanopt(mp->mnt_optnew, "gid", "%d", &v) == 1)
163 pmp->pm_gid = v;
164 if (vfs_scanopt(mp->mnt_optnew, "uid", "%d", &v) == 1)
165 pmp->pm_uid = v;
166 if (vfs_scanopt(mp->mnt_optnew, "mask", "%d", &v) == 1)
167 pmp->pm_mask = v & ALLPERMS;
168 if (vfs_scanopt(mp->mnt_optnew, "dirmask", "%d", &v) == 1)
169 pmp->pm_dirmask = v & ALLPERMS;
170 vfs_flagopt(mp->mnt_optnew, "shortname",
171 &pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
172 vfs_flagopt(mp->mnt_optnew, "shortnames",
173 &pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
174 vfs_flagopt(mp->mnt_optnew, "longname",
175 &pmp->pm_flags, MSDOSFSMNT_LONGNAME);
176 vfs_flagopt(mp->mnt_optnew, "longnames",
177 &pmp->pm_flags, MSDOSFSMNT_LONGNAME);
178 vfs_flagopt(mp->mnt_optnew, "kiconv",
179 &pmp->pm_flags, MSDOSFSMNT_KICONV);
180
181 if (vfs_getopt(mp->mnt_optnew, "nowin95", NULL, NULL) == 0)
182 pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
183 else
184 pmp->pm_flags &= ~MSDOSFSMNT_NOWIN95;
185
186 if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
187 pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
188 else
189 pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
190 return 0;
191 }
192
193 static int
194 msdosfs_cmount(struct mntarg *ma, void *data, uint64_t flags)
195 {
196 struct msdosfs_args args;
197 int error;
198
199 if (data == NULL)
200 return (EINVAL);
201 error = copyin(data, &args, sizeof args);
202 if (error)
203 return (error);
204
205 ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
206 ma = mount_arg(ma, "export", &args.export, sizeof(args.export));
207 ma = mount_argf(ma, "uid", "%d", args.uid);
208 ma = mount_argf(ma, "gid", "%d", args.gid);
209 ma = mount_argf(ma, "mask", "%d", args.mask);
210 ma = mount_argf(ma, "dirmask", "%d", args.dirmask);
211
212 ma = mount_argb(ma, args.flags & MSDOSFSMNT_SHORTNAME, "noshortname");
213 ma = mount_argb(ma, args.flags & MSDOSFSMNT_LONGNAME, "nolongname");
214 ma = mount_argb(ma, !(args.flags & MSDOSFSMNT_NOWIN95), "nowin95");
215 ma = mount_argb(ma, args.flags & MSDOSFSMNT_KICONV, "nokiconv");
216
217 ma = mount_argsu(ma, "cs_win", args.cs_win, MAXCSLEN);
218 ma = mount_argsu(ma, "cs_dos", args.cs_dos, MAXCSLEN);
219 ma = mount_argsu(ma, "cs_local", args.cs_local, MAXCSLEN);
220
221 error = kernel_mount(ma, flags);
222
223 return (error);
224 }
225
226 /*
227 * mp - path - addr in user space of mount point (ie /usr or whatever)
228 * data - addr in user space of mount params including the name of the block
229 * special file to treat as a filesystem.
230 */
231 static int
232 msdosfs_mount(struct mount *mp)
233 {
234 struct vnode *devvp, *odevvp; /* vnode for blk device to mount */
235 struct thread *td;
236 /* msdosfs specific mount control block */
237 struct msdosfsmount *pmp = NULL;
238 struct nameidata ndp;
239 int error, flags;
240 accmode_t accmode;
241 char *from;
242
243 td = curthread;
244 if (vfs_filteropt(mp->mnt_optnew, msdosfs_opts))
245 return (EINVAL);
246
247 /*
248 * If updating, check whether changing from read-only to
249 * read/write; if there is no device name, that's all we do.
250 */
251 if (mp->mnt_flag & MNT_UPDATE) {
252 pmp = VFSTOMSDOSFS(mp);
253 if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
254 vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
255 if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0)
256 return (error);
257 error = vfs_write_suspend_umnt(mp);
258 if (error != 0)
259 return (error);
260
261 flags = WRITECLOSE;
262 if (mp->mnt_flag & MNT_FORCE)
263 flags |= FORCECLOSE;
264 error = vflush(mp, 0, flags, td);
265 if (error != 0) {
266 vfs_write_resume(mp, 0);
267 return (error);
268 }
269
270 /*
271 * Now the volume is clean. Mark it so while the
272 * device is still rw.
273 */
274 error = markvoldirty(pmp, 0);
275 if (error != 0) {
276 vfs_write_resume(mp, 0);
277 (void)markvoldirty(pmp, 1);
278 return (error);
279 }
280
281 /* Downgrade the device from rw to ro. */
282 g_topology_lock();
283 error = g_access(pmp->pm_cp, 0, -1, 0);
284 g_topology_unlock();
285 if (error) {
286 vfs_write_resume(mp, 0);
287 (void)markvoldirty(pmp, 1);
288 return (error);
289 }
290
291 /*
292 * Backing out after an error was painful in the
293 * above. Now we are committed to succeeding.
294 */
295 pmp->pm_fmod = 0;
296 pmp->pm_flags |= MSDOSFSMNT_RONLY;
297 MNT_ILOCK(mp);
298 mp->mnt_flag |= MNT_RDONLY;
299 MNT_IUNLOCK(mp);
300 vfs_write_resume(mp, 0);
301 } else if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
302 !vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
303 /*
304 * If upgrade to read-write by non-root, then verify
305 * that user has necessary permissions on the device.
306 */
307 odevvp = pmp->pm_odevvp;
308 vn_lock(odevvp, LK_EXCLUSIVE | LK_RETRY);
309 error = VOP_ACCESS(odevvp, VREAD | VWRITE,
310 td->td_ucred, td);
311 if (error)
312 error = priv_check(td, PRIV_VFS_MOUNT_PERM);
313 if (error) {
314 VOP_UNLOCK(odevvp);
315 return (error);
316 }
317 VOP_UNLOCK(odevvp);
318 g_topology_lock();
319 error = g_access(pmp->pm_cp, 0, 1, 0);
320 g_topology_unlock();
321 if (error)
322 return (error);
323
324 /* Now that the volume is modifiable, mark it dirty. */
325 error = markvoldirty_upgrade(pmp, true, true);
326 if (error) {
327 /*
328 * If dirtying the superblock failed, drop GEOM
329 * 'w' refs (we're still RO).
330 */
331 g_topology_lock();
332 (void)g_access(pmp->pm_cp, 0, -1, 0);
333 g_topology_unlock();
334
335 return (error);
336 }
337
338 pmp->pm_fmod = 1;
339 pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
340 MNT_ILOCK(mp);
341 mp->mnt_flag &= ~MNT_RDONLY;
342 MNT_IUNLOCK(mp);
343 }
344
345 /*
346 * Avoid namei() below. The "from" option is not set.
347 * Update of the devvp is pointless for this case.
348 */
349 if ((pmp->pm_flags & MSDOSFS_ERR_RO) != 0)
350 return (0);
351 }
352 /*
353 * Not an update, or updating the name: look up the name
354 * and verify that it refers to a sensible disk device.
355 */
356 if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
357 return (EINVAL);
358 NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, from);
359 error = namei(&ndp);
360 if (error)
361 return (error);
362 devvp = ndp.ni_vp;
363 NDFREE_PNBUF(&ndp);
364
365 if (!vn_isdisk_error(devvp, &error)) {
366 vput(devvp);
367 return (error);
368 }
369 /*
370 * If mount by non-root, then verify that user has necessary
371 * permissions on the device.
372 */
373 accmode = VREAD;
374 if ((mp->mnt_flag & MNT_RDONLY) == 0)
375 accmode |= VWRITE;
376 error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
377 if (error)
378 error = priv_check(td, PRIV_VFS_MOUNT_PERM);
379 if (error) {
380 vput(devvp);
381 return (error);
382 }
383 if ((mp->mnt_flag & MNT_UPDATE) == 0) {
384 error = mountmsdosfs(devvp, mp);
385 #ifdef MSDOSFS_DEBUG /* only needed for the printf below */
386 pmp = VFSTOMSDOSFS(mp);
387 #endif
388 } else {
389 vput(devvp);
390 if (devvp != pmp->pm_odevvp)
391 return (EINVAL); /* XXX needs translation */
392 }
393 if (error) {
394 vrele(devvp);
395 return (error);
396 }
397
398 error = update_mp(mp, td);
399 if (error) {
400 if ((mp->mnt_flag & MNT_UPDATE) == 0)
401 msdosfs_unmount(mp, MNT_FORCE);
402 return error;
403 }
404
405 vfs_mountedfrom(mp, from);
406 #ifdef MSDOSFS_DEBUG
407 printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
408 #endif
409 return (0);
410 }
411
412 static int
413 mountmsdosfs(struct vnode *odevvp, struct mount *mp)
414 {
415 struct msdosfsmount *pmp;
416 struct buf *bp;
417 struct cdev *dev;
418 struct vnode *devvp;
419 union bootsector *bsp;
420 struct byte_bpb33 *b33;
421 struct byte_bpb50 *b50;
422 struct byte_bpb710 *b710;
423 uint8_t SecPerClust;
424 u_long clusters;
425 int ronly, error;
426 struct g_consumer *cp;
427 struct bufobj *bo;
428
429 bp = NULL; /* This and pmp both used in error_exit. */
430 pmp = NULL;
431 ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
432
433 devvp = mntfs_allocvp(mp, odevvp);
434 dev = devvp->v_rdev;
435 if (atomic_cmpset_acq_ptr((uintptr_t *)&dev->si_mountpt, 0,
436 (uintptr_t)mp) == 0) {
437 mntfs_freevp(devvp);
438 return (EBUSY);
439 }
440 g_topology_lock();
441 error = g_vfs_open(devvp, &cp, "msdosfs", ronly ? 0 : 1);
442 g_topology_unlock();
443 if (error != 0) {
444 atomic_store_rel_ptr((uintptr_t *)&dev->si_mountpt, 0);
445 mntfs_freevp(devvp);
446 return (error);
447 }
448 dev_ref(dev);
449 bo = &devvp->v_bufobj;
450 BO_LOCK(&odevvp->v_bufobj);
451 odevvp->v_bufobj.bo_flag |= BO_NOBUFS;
452 BO_UNLOCK(&odevvp->v_bufobj);
453 VOP_UNLOCK(devvp);
454 if (dev->si_iosize_max != 0)
455 mp->mnt_iosize_max = dev->si_iosize_max;
456 if (mp->mnt_iosize_max > maxphys)
457 mp->mnt_iosize_max = maxphys;
458
459 /*
460 * Read the boot sector of the filesystem, and then check the
461 * boot signature. If not a dos boot sector then error out.
462 *
463 * NOTE: 8192 is a magic size that works for ffs.
464 */
465 error = bread(devvp, 0, 8192, NOCRED, &bp);
466 if (error)
467 goto error_exit;
468 bp->b_flags |= B_AGE;
469 bsp = (union bootsector *)bp->b_data;
470 b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
471 b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
472 b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
473
474 #ifndef MSDOSFS_NOCHECKSIG
475 if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 ||
476 bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
477 error = EINVAL;
478 goto error_exit;
479 }
480 #endif
481
482 pmp = malloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK | M_ZERO);
483 pmp->pm_mountp = mp;
484 pmp->pm_cp = cp;
485 pmp->pm_bo = bo;
486
487 lockinit(&pmp->pm_fatlock, 0, msdosfs_lock_msg, 0, 0);
488 lockinit(&pmp->pm_checkpath_lock, 0, "msdoscp", 0, 0);
489
490 TASK_INIT(&pmp->pm_rw2ro_task, 0, msdosfs_remount_ro, pmp);
491
492 /*
493 * Initialize ownerships and permissions, since nothing else will
494 * initialize them iff we are mounting root.
495 */
496 pmp->pm_uid = UID_ROOT;
497 pmp->pm_gid = GID_WHEEL;
498 pmp->pm_mask = pmp->pm_dirmask = S_IXUSR | S_IXGRP | S_IXOTH |
499 S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR;
500
501 /*
502 * Compute several useful quantities from the bpb in the
503 * bootsector. Copy in the dos 5 variant of the bpb then fix up
504 * the fields that are different between dos 5 and dos 3.3.
505 */
506 SecPerClust = b50->bpbSecPerClust;
507 pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
508 if (pmp->pm_BytesPerSec < DEV_BSIZE) {
509 error = EINVAL;
510 goto error_exit;
511 }
512 pmp->pm_ResSectors = getushort(b50->bpbResSectors);
513 pmp->pm_FATs = b50->bpbFATs;
514 pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
515 pmp->pm_Sectors = getushort(b50->bpbSectors);
516 pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
517 pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
518 pmp->pm_Heads = getushort(b50->bpbHeads);
519 pmp->pm_Media = b50->bpbMedia;
520
521 /* calculate the ratio of sector size to DEV_BSIZE */
522 pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
523
524 /*
525 * We don't check pm_Heads nor pm_SecPerTrack, because
526 * these may not be set for EFI file systems. We don't
527 * use these anyway, so we're unaffected if they are
528 * invalid.
529 */
530 if (pmp->pm_BytesPerSec == 0 || SecPerClust == 0) {
531 error = EINVAL;
532 goto error_exit;
533 }
534
535 if (pmp->pm_Sectors == 0) {
536 pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
537 pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
538 } else {
539 pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
540 pmp->pm_HugeSectors = pmp->pm_Sectors;
541 }
542
543 if (pmp->pm_RootDirEnts == 0) {
544 if (pmp->pm_FATsecs != 0 || getushort(b710->bpbFSVers) != 0) {
545 error = EINVAL;
546 #ifdef MSDOSFS_DEBUG
547 printf("mountmsdosfs(): bad FAT32 filesystem\n");
548 #endif
549 goto error_exit;
550 }
551 pmp->pm_fatmask = FAT32_MASK;
552 pmp->pm_fatmult = 4;
553 pmp->pm_fatdiv = 1;
554 pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
555 if ((getushort(b710->bpbExtFlags) & FATMIRROR) != 0)
556 pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
557 else
558 pmp->pm_flags |= MSDOSFS_FATMIRROR;
559 } else
560 pmp->pm_flags |= MSDOSFS_FATMIRROR;
561
562 /*
563 * Check a few values (could do some more):
564 * - logical sector size: power of 2, >= block size
565 * - sectors per cluster: power of 2, >= 1
566 * - number of sectors: >= 1, <= size of partition
567 * - number of FAT sectors: >= 1
568 */
569 if (SecPerClust == 0 || (SecPerClust & (SecPerClust - 1)) != 0 ||
570 pmp->pm_BytesPerSec < DEV_BSIZE ||
571 (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1)) != 0 ||
572 pmp->pm_HugeSectors == 0 || pmp->pm_FATsecs == 0 ||
573 SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE) {
574 error = EINVAL;
575 goto error_exit;
576 }
577
578 if ((off_t)pmp->pm_HugeSectors * pmp->pm_BytesPerSec <
579 pmp->pm_HugeSectors /* overflow */ ||
580 (off_t)pmp->pm_HugeSectors * pmp->pm_BytesPerSec >
581 cp->provider->mediasize /* past end of vol */) {
582 error = EINVAL;
583 goto error_exit;
584 }
585
586 pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
587 pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
588 pmp->pm_FATsecs *= pmp->pm_BlkPerSec;
589 SecPerClust *= pmp->pm_BlkPerSec;
590
591 pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
592
593 if (FAT32(pmp)) {
594 pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
595 pmp->pm_firstcluster = pmp->pm_fatblk +
596 pmp->pm_FATs * pmp->pm_FATsecs;
597 pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
598 } else {
599 pmp->pm_rootdirblk = pmp->pm_fatblk +
600 pmp->pm_FATs * pmp->pm_FATsecs;
601 pmp->pm_rootdirsize = howmany(pmp->pm_RootDirEnts *
602 sizeof(struct direntry), DEV_BSIZE); /* in blocks */
603 pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
604 }
605
606 if (pmp->pm_HugeSectors <= pmp->pm_firstcluster) {
607 error = EINVAL;
608 goto error_exit;
609 }
610 pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
611 SecPerClust + 1;
612 pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
613
614 if (pmp->pm_fatmask == 0) {
615 if (pmp->pm_maxcluster <= ((CLUST_RSRVD - CLUST_FIRST) &
616 FAT12_MASK)) {
617 /*
618 * This will usually be a floppy disk. This size makes
619 * sure that one FAT entry will not be split across
620 * multiple blocks.
621 */
622 pmp->pm_fatmask = FAT12_MASK;
623 pmp->pm_fatmult = 3;
624 pmp->pm_fatdiv = 2;
625 } else {
626 pmp->pm_fatmask = FAT16_MASK;
627 pmp->pm_fatmult = 2;
628 pmp->pm_fatdiv = 1;
629 }
630 }
631
632 clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
633 if (pmp->pm_maxcluster >= clusters) {
634 #ifdef MSDOSFS_DEBUG
635 printf("Warning: number of clusters (%ld) exceeds FAT "
636 "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
637 #endif
638 pmp->pm_maxcluster = clusters - 1;
639 }
640
641 if (FAT12(pmp))
642 pmp->pm_fatblocksize = 3 * 512;
643 else
644 pmp->pm_fatblocksize = PAGE_SIZE;
645 pmp->pm_fatblocksize = roundup(pmp->pm_fatblocksize,
646 pmp->pm_BytesPerSec);
647 pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
648 pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
649
650 /*
651 * Compute mask and shift value for isolating cluster relative byte
652 * offsets and cluster numbers from a file offset.
653 */
654 pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
655 pmp->pm_crbomask = pmp->pm_bpcluster - 1;
656 pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
657
658 /*
659 * Check for valid cluster size
660 * must be a power of 2
661 */
662 if ((pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) != 0) {
663 error = EINVAL;
664 goto error_exit;
665 }
666
667 /*
668 * Release the bootsector buffer.
669 */
670 brelse(bp);
671 bp = NULL;
672
673 /*
674 * Check the fsinfo sector if we have one. Silently fix up our
675 * in-core copy of fp->fsinxtfree if it is unknown (0xffffffff)
676 * or too large. Ignore fp->fsinfree for now, since we need to
677 * read the entire FAT anyway to fill the inuse map.
678 */
679 if (pmp->pm_fsinfo) {
680 struct fsinfo *fp;
681
682 if ((error = bread(devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec,
683 NOCRED, &bp)) != 0)
684 goto error_exit;
685 fp = (struct fsinfo *)bp->b_data;
686 if (!bcmp(fp->fsisig1, "RRaA", 4) &&
687 !bcmp(fp->fsisig2, "rrAa", 4) &&
688 !bcmp(fp->fsisig3, "\0\0\125\252", 4)) {
689 pmp->pm_nxtfree = getulong(fp->fsinxtfree);
690 if (pmp->pm_nxtfree > pmp->pm_maxcluster)
691 pmp->pm_nxtfree = CLUST_FIRST;
692 } else
693 pmp->pm_fsinfo = 0;
694 brelse(bp);
695 bp = NULL;
696 }
697
698 /*
699 * Finish initializing pmp->pm_nxtfree (just in case the first few
700 * sectors aren't properly reserved in the FAT). This completes
701 * the fixup for fp->fsinxtfree, and fixes up the zero-initialized
702 * value if there is no fsinfo. We will use pmp->pm_nxtfree
703 * internally even if there is no fsinfo.
704 */
705 if (pmp->pm_nxtfree < CLUST_FIRST)
706 pmp->pm_nxtfree = CLUST_FIRST;
707
708 /*
709 * Allocate memory for the bitmap of allocated clusters, and then
710 * fill it in.
711 */
712 pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1,
713 N_INUSEBITS) * sizeof(*pmp->pm_inusemap), M_MSDOSFSFAT, M_WAITOK);
714
715 /*
716 * fillinusemap() needs pm_devvp.
717 */
718 pmp->pm_devvp = devvp;
719 pmp->pm_odevvp = odevvp;
720 pmp->pm_dev = dev;
721
722 /*
723 * Have the inuse map filled in.
724 */
725 MSDOSFS_LOCK_MP(pmp);
726 error = fillinusemap(pmp);
727 MSDOSFS_UNLOCK_MP(pmp);
728 if (error != 0)
729 goto error_exit;
730
731 /*
732 * If they want FAT updates to be synchronous then let them suffer
733 * the performance degradation in exchange for the on disk copy of
734 * the FAT being correct just about all the time. I suppose this
735 * would be a good thing to turn on if the kernel is still flakey.
736 */
737 if (mp->mnt_flag & MNT_SYNCHRONOUS)
738 pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
739
740 /*
741 * Finish up.
742 */
743 if (ronly)
744 pmp->pm_flags |= MSDOSFSMNT_RONLY;
745 else {
746 if ((error = markvoldirty(pmp, 1)) != 0)
747 goto error_exit;
748 pmp->pm_fmod = 1;
749 }
750 mp->mnt_data = pmp;
751 mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
752 mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
753 MNT_ILOCK(mp);
754 mp->mnt_flag |= MNT_LOCAL;
755 mp->mnt_kern_flag |= MNTK_USES_BCACHE | MNTK_NO_IOPF;
756 MNT_IUNLOCK(mp);
757
758 return (0);
759
760 error_exit:
761 if (bp != NULL)
762 brelse(bp);
763 if (cp != NULL) {
764 g_topology_lock();
765 g_vfs_close(cp);
766 g_topology_unlock();
767 }
768 if (pmp != NULL) {
769 lockdestroy(&pmp->pm_fatlock);
770 lockdestroy(&pmp->pm_checkpath_lock);
771 free(pmp->pm_inusemap, M_MSDOSFSFAT);
772 free(pmp, M_MSDOSFSMNT);
773 mp->mnt_data = NULL;
774 }
775 BO_LOCK(&odevvp->v_bufobj);
776 odevvp->v_bufobj.bo_flag &= ~BO_NOBUFS;
777 BO_UNLOCK(&odevvp->v_bufobj);
778 atomic_store_rel_ptr((uintptr_t *)&dev->si_mountpt, 0);
779 vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
780 mntfs_freevp(devvp);
781 dev_rel(dev);
782 return (error);
783 }
784
785 /*
786 * Unmount the filesystem described by mp.
787 */
788 static int
789 msdosfs_unmount(struct mount *mp, int mntflags)
790 {
791 struct msdosfsmount *pmp;
792 int error, flags;
793 bool susp;
794
795 error = flags = 0;
796 pmp = VFSTOMSDOSFS(mp);
797 susp = (pmp->pm_flags & MSDOSFSMNT_RONLY) == 0;
798
799 if (susp) {
800 error = vfs_write_suspend_umnt(mp);
801 if (error != 0)
802 return (error);
803 }
804
805 if ((mntflags & MNT_FORCE) != 0)
806 flags |= FORCECLOSE;
807 error = vflush(mp, 0, flags, curthread);
808 if (error != 0 && error != ENXIO) {
809 if (susp)
810 vfs_write_resume(mp, VR_START_WRITE);
811 return (error);
812 }
813 if (susp) {
814 error = markvoldirty(pmp, 0);
815 if (error != 0 && error != ENXIO) {
816 if (susp)
817 vfs_write_resume(mp, VR_START_WRITE);
818 (void)markvoldirty(pmp, 1);
819 return (error);
820 }
821 }
822 if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
823 if (pmp->pm_w2u)
824 msdosfs_iconv->close(pmp->pm_w2u);
825 if (pmp->pm_u2w)
826 msdosfs_iconv->close(pmp->pm_u2w);
827 if (pmp->pm_d2u)
828 msdosfs_iconv->close(pmp->pm_d2u);
829 if (pmp->pm_u2d)
830 msdosfs_iconv->close(pmp->pm_u2d);
831 }
832
833 #ifdef MSDOSFS_DEBUG
834 {
835 struct vnode *vp = pmp->pm_devvp;
836 struct bufobj *bo;
837
838 bo = &vp->v_bufobj;
839 BO_LOCK(bo);
840 VI_LOCK(vp);
841 vn_printf(vp,
842 "msdosfs_umount(): just before calling VOP_CLOSE()\n");
843 printf("freef %p, freeb %p, mount %p\n",
844 TAILQ_NEXT(vp, v_vnodelist), vp->v_vnodelist.tqe_prev,
845 vp->v_mount);
846 printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
847 TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd),
848 TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd),
849 vp->v_bufobj.bo_numoutput, vp->v_type);
850 VI_UNLOCK(vp);
851 BO_UNLOCK(bo);
852 }
853 #endif
854 if (susp)
855 vfs_write_resume(mp, VR_START_WRITE);
856
857 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
858 g_topology_lock();
859 g_vfs_close(pmp->pm_cp);
860 g_topology_unlock();
861 BO_LOCK(&pmp->pm_odevvp->v_bufobj);
862 pmp->pm_odevvp->v_bufobj.bo_flag &= ~BO_NOBUFS;
863 BO_UNLOCK(&pmp->pm_odevvp->v_bufobj);
864 atomic_store_rel_ptr((uintptr_t *)&pmp->pm_dev->si_mountpt, 0);
865 mntfs_freevp(pmp->pm_devvp);
866 vrele(pmp->pm_odevvp);
867 dev_rel(pmp->pm_dev);
868 free(pmp->pm_inusemap, M_MSDOSFSFAT);
869 lockdestroy(&pmp->pm_fatlock);
870 lockdestroy(&pmp->pm_checkpath_lock);
871 free(pmp, M_MSDOSFSMNT);
872 mp->mnt_data = NULL;
873 return (error);
874 }
875
876 static void
877 msdosfs_remount_ro(void *arg, int pending)
878 {
879 struct msdosfsmount *pmp;
880 int error;
881
882 pmp = arg;
883
884 MSDOSFS_LOCK_MP(pmp);
885 if ((pmp->pm_flags & MSDOSFS_ERR_RO) != 0) {
886 while ((pmp->pm_flags & MSDOSFS_ERR_RO) != 0)
887 msleep(&pmp->pm_flags, &pmp->pm_fatlock, PVFS,
888 "msdoserrro", hz);
889 } else if ((pmp->pm_mountp->mnt_flag & MNT_RDONLY) == 0) {
890 pmp->pm_flags |= MSDOSFS_ERR_RO;
891 MSDOSFS_UNLOCK_MP(pmp);
892 printf("%s: remounting read-only due to corruption\n",
893 pmp->pm_mountp->mnt_stat.f_mntfromname);
894 error = vfs_remount_ro(pmp->pm_mountp);
895 if (error != 0)
896 printf("%s: remounting read-only failed: error %d\n",
897 pmp->pm_mountp->mnt_stat.f_mntfromname, error);
898 else
899 printf("remounted %s read-only\n",
900 pmp->pm_mountp->mnt_stat.f_mntfromname);
901 MSDOSFS_LOCK_MP(pmp);
902 pmp->pm_flags &= ~MSDOSFS_ERR_RO;
903 wakeup(&pmp->pm_flags);
904 }
905 MSDOSFS_UNLOCK_MP(pmp);
906
907 vfs_unbusy(pmp->pm_mountp);
908 }
909
910 void
911 msdosfs_integrity_error(struct msdosfsmount *pmp)
912 {
913 int error;
914
915 error = vfs_busy(pmp->pm_mountp, MBF_NOWAIT);
916 if (error == 0)
917 taskqueue_enqueue(taskqueue_thread, &pmp->pm_rw2ro_task);
918 else
919 printf("%s: integrity error busying failed, error %d\n",
920 pmp->pm_mountp->mnt_stat.f_mntfromname, error);
921 }
922
923 static int
924 msdosfs_root(struct mount *mp, int flags, struct vnode **vpp)
925 {
926 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
927 struct denode *ndep;
928 int error;
929
930 #ifdef MSDOSFS_DEBUG
931 printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
932 #endif
933 error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, LK_EXCLUSIVE, &ndep);
934 if (error)
935 return (error);
936 *vpp = DETOV(ndep);
937 return (0);
938 }
939
940 static int
941 msdosfs_statfs(struct mount *mp, struct statfs *sbp)
942 {
943 struct msdosfsmount *pmp;
944
945 pmp = VFSTOMSDOSFS(mp);
946 sbp->f_bsize = pmp->pm_bpcluster;
947 sbp->f_iosize = pmp->pm_bpcluster;
948 sbp->f_blocks = pmp->pm_maxcluster + 1;
949 sbp->f_bfree = pmp->pm_freeclustercount;
950 sbp->f_bavail = pmp->pm_freeclustercount;
951 sbp->f_files = pmp->pm_RootDirEnts; /* XXX */
952 sbp->f_ffree = 0; /* what to put in here? */
953 return (0);
954 }
955
956 /*
957 * If we have an FSInfo block, update it.
958 */
959 static int
960 msdosfs_fsiflush(struct msdosfsmount *pmp, int waitfor)
961 {
962 struct fsinfo *fp;
963 struct buf *bp;
964 int error;
965
966 MSDOSFS_LOCK_MP(pmp);
967 if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) {
968 error = 0;
969 goto unlock;
970 }
971 error = bread(pmp->pm_devvp, pmp->pm_fsinfo, pmp->pm_BytesPerSec,
972 NOCRED, &bp);
973 if (error != 0) {
974 goto unlock;
975 }
976 fp = (struct fsinfo *)bp->b_data;
977 putulong(fp->fsinfree, pmp->pm_freeclustercount);
978 putulong(fp->fsinxtfree, pmp->pm_nxtfree);
979 pmp->pm_flags &= ~MSDOSFS_FSIMOD;
980 if (waitfor == MNT_WAIT)
981 error = bwrite(bp);
982 else
983 bawrite(bp);
984 unlock:
985 MSDOSFS_UNLOCK_MP(pmp);
986 return (error);
987 }
988
989 static int
990 msdosfs_sync(struct mount *mp, int waitfor)
991 {
992 struct vnode *vp, *nvp;
993 struct thread *td;
994 struct denode *dep;
995 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
996 int error, allerror = 0;
997
998 td = curthread;
999
1000 /*
1001 * If we ever switch to not updating all of the FATs all the time,
1002 * this would be the place to update them from the first one.
1003 */
1004 if (pmp->pm_fmod != 0) {
1005 if (pmp->pm_flags & MSDOSFSMNT_RONLY)
1006 panic("msdosfs_sync: rofs mod");
1007 else {
1008 /* update FATs here */
1009 }
1010 }
1011 /*
1012 * Write back each (modified) denode.
1013 */
1014 loop:
1015 MNT_VNODE_FOREACH_ALL(vp, mp, nvp) {
1016 if (vp->v_type == VNON) {
1017 VI_UNLOCK(vp);
1018 continue;
1019 }
1020 dep = VTODE(vp);
1021 if ((dep->de_flag &
1022 (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
1023 (vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
1024 waitfor == MNT_LAZY)) {
1025 VI_UNLOCK(vp);
1026 continue;
1027 }
1028 error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK);
1029 if (error) {
1030 if (error == ENOENT) {
1031 MNT_VNODE_FOREACH_ALL_ABORT(mp, nvp);
1032 goto loop;
1033 }
1034 continue;
1035 }
1036 error = VOP_FSYNC(vp, waitfor, td);
1037 if (error)
1038 allerror = error;
1039 vput(vp);
1040 }
1041
1042 /*
1043 * Flush filesystem control info.
1044 */
1045 if (waitfor != MNT_LAZY) {
1046 vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
1047 error = VOP_FSYNC(pmp->pm_devvp, waitfor, td);
1048 if (error)
1049 allerror = error;
1050 VOP_UNLOCK(pmp->pm_devvp);
1051 }
1052
1053 error = msdosfs_fsiflush(pmp, waitfor);
1054 if (error != 0)
1055 allerror = error;
1056
1057 if (allerror == 0 && waitfor == MNT_SUSPEND) {
1058 MNT_ILOCK(mp);
1059 mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED;
1060 MNT_IUNLOCK(mp);
1061 }
1062 return (allerror);
1063 }
1064
1065 static int
1066 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
1067 {
1068 struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
1069 struct defid *defhp = (struct defid *) fhp;
1070 struct denode *dep;
1071 int error;
1072
1073 error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs,
1074 LK_EXCLUSIVE, &dep);
1075 if (error) {
1076 *vpp = NULLVP;
1077 return (error);
1078 }
1079 *vpp = DETOV(dep);
1080 vnode_create_vobject(*vpp, dep->de_FileSize, curthread);
1081 return (0);
1082 }
1083
1084 static struct vfsops msdosfs_vfsops = {
1085 .vfs_fhtovp = msdosfs_fhtovp,
1086 .vfs_mount = msdosfs_mount,
1087 .vfs_cmount = msdosfs_cmount,
1088 .vfs_root = msdosfs_root,
1089 .vfs_statfs = msdosfs_statfs,
1090 .vfs_sync = msdosfs_sync,
1091 .vfs_unmount = msdosfs_unmount,
1092 };
1093
1094 VFS_SET(msdosfs_vfsops, msdosfs, 0);
1095 MODULE_VERSION(msdosfs, 1);
Cache object: 1049a23f029a9cb105d90fe1a0f104bf
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