xref: /dragonfly/sys/vfs/msdosfs/msdosfs_vfsops.c (revision 2cd2d2b5)
1 /* $FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/msdosfs/Attic/msdosfs_vfsops.c,v 1.60.2.8 2004/03/02 09:43:04 tjr Exp $ */
2 /* $DragonFly: src/sys/vfs/msdosfs/msdosfs_vfsops.c,v 1.18 2004/08/17 18:57:34 dillon Exp $ */
3 /*	$NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws Exp $	*/
4 
5 /*-
6  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
7  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
8  * All rights reserved.
9  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by TooLs GmbH.
22  * 4. The name of TooLs GmbH may not be used to endorse or promote products
23  *    derived from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
34  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 /*
37  * Written by Paul Popelka (paulp@uts.amdahl.com)
38  *
39  * You can do anything you want with this software, just don't say you wrote
40  * it, and don't remove this notice.
41  *
42  * This software is provided "as is".
43  *
44  * The author supplies this software to be publicly redistributed on the
45  * understanding that the author is not responsible for the correct
46  * functioning of this software in any circumstances and is not liable for
47  * any damages caused by this software.
48  *
49  * October 1992
50  */
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/conf.h>
55 #include <sys/proc.h>
56 #include <sys/namei.h>
57 #include <sys/kernel.h>
58 #include <sys/vnode.h>
59 #include <sys/mount.h>
60 #include <sys/buf.h>
61 #include <sys/fcntl.h>
62 #include <sys/malloc.h>
63 #include <sys/stat.h> 				/* defines ALLPERMS */
64 #include <vm/vm_zone.h>
65 
66 #include "bpb.h"
67 #include "bootsect.h"
68 #include "direntry.h"
69 #include "denode.h"
70 #include "msdosfsmount.h"
71 #include "fat.h"
72 
73 extern struct vnodeopv_entry_desc msdosfs_vnodeop_entries[];
74 
75 #define MSDOSFS_DFLTBSIZE       4096
76 
77 #if 1 /*def PC98*/
78 /*
79  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
80  *       garbage or a random value :-{
81  *       If you want to use that broken-signatured media, define the
82  *       following symbol even though PC/AT.
83  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
84  */
85 #define	MSDOSFS_NOCHECKSIG
86 #endif
87 
88 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
89 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
90 
91 static int	update_mp (struct mount *mp, struct msdosfs_args *argp);
92 static int	mountmsdosfs (struct vnode *devvp, struct mount *mp,
93 				  struct thread *td, struct msdosfs_args *argp);
94 static int	msdosfs_fhtovp (struct mount *, struct fid *,
95 				    struct vnode **);
96 static int	msdosfs_checkexp (struct mount *, struct sockaddr *,
97 				    int *, struct ucred **);
98 static int	msdosfs_mount (struct mount *, char *, caddr_t,
99 				   struct nameidata *, struct thread *);
100 static int	msdosfs_root (struct mount *, struct vnode **);
101 static int	msdosfs_statfs (struct mount *, struct statfs *,
102 				    struct thread *);
103 static int	msdosfs_sync (struct mount *, int, struct thread *);
104 static int	msdosfs_unmount (struct mount *, int, struct thread *);
105 static int	msdosfs_vptofh (struct vnode *, struct fid *);
106 
107 static int
108 update_mp(struct mount *mp, struct msdosfs_args *argp)
109 {
110 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
111 	int error;
112 
113 	pmp->pm_gid = argp->gid;
114 	pmp->pm_uid = argp->uid;
115 	pmp->pm_mask = argp->mask & ALLPERMS;
116 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
117 	if (pmp->pm_flags & MSDOSFSMNT_U2WTABLE) {
118 		bcopy(argp->u2w, pmp->pm_u2w, sizeof(pmp->pm_u2w));
119 		bcopy(argp->d2u, pmp->pm_d2u, sizeof(pmp->pm_d2u));
120 		bcopy(argp->u2d, pmp->pm_u2d, sizeof(pmp->pm_u2d));
121 	}
122 	if (pmp->pm_flags & MSDOSFSMNT_ULTABLE) {
123 		bcopy(argp->ul, pmp->pm_ul, sizeof(pmp->pm_ul));
124 		bcopy(argp->lu, pmp->pm_lu, sizeof(pmp->pm_lu));
125 	}
126 
127 #ifndef __DragonFly__
128 	/*
129 	 * GEMDOS knows nothing (yet) about win95
130 	 */
131 	if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
132 		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
133 #endif
134 
135 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
136 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
137 	else if (!(pmp->pm_flags &
138 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
139 		struct vnode *rootvp;
140 
141 		/*
142 		 * Try to divine whether to support Win'95 long filenames
143 		 */
144 		if (FAT32(pmp))
145 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
146 		else {
147 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
148 				return error;
149 			pmp->pm_flags |= findwin95(VTODE(rootvp))
150 				? MSDOSFSMNT_LONGNAME
151 					: MSDOSFSMNT_SHORTNAME;
152 			vput(rootvp);
153 		}
154 	}
155 	return 0;
156 }
157 
158 #ifndef __DragonFly__
159 int
160 msdosfs_mountroot(void)
161 {
162 	struct mount *mp;
163 	struct thread *td = curthread;	/* XXX */
164 	size_t size;
165 	int error;
166 	struct msdosfs_args args;
167 
168 	if (root_device->dv_class != DV_DISK)
169 		return (ENODEV);
170 
171 	/*
172 	 * Get vnodes for swapdev and rootdev.
173 	 */
174 	if (bdevvp(rootdev, &rootvp))
175 		panic("msdosfs_mountroot: can't setup rootvp");
176 
177 	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
178 	bzero((char *)mp, (u_long)sizeof(struct mount));
179 	mp->mnt_op = &msdosfs_vfsops;
180 	mp->mnt_flag = 0;
181 	TAILQ_INIT(&mp->mnt_nvnodelist);
182 	TAILQ_INIT(&mp->mnt_reservedvnlist);
183 
184 	args.flags = 0;
185 	args.uid = 0;
186 	args.gid = 0;
187 	args.mask = 0777;
188 
189 	if ((error = mountmsdosfs(rootvp, mp, p, &args)) != 0) {
190 		free(mp, M_MOUNT);
191 		return (error);
192 	}
193 
194 	if ((error = update_mp(mp, &args)) != 0) {
195 		(void)msdosfs_unmount(mp, 0, p);
196 		free(mp, M_MOUNT);
197 		return (error);
198 	}
199 
200 	if ((error = vfs_lock(mp)) != 0) {
201 		(void)msdosfs_unmount(mp, 0, p);
202 		free(mp, M_MOUNT);
203 		return (error);
204 	}
205 
206 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
207 	mp->mnt_vnodecovered = NULLVP;
208 	(void) copystr("/", mp->mnt_stat.f_mntonname, MNAMELEN - 1,
209 	    &size);
210 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
211 	(void) copystr(ROOTNAME, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
212 	    &size);
213 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
214 
215 	(void)msdosfs_statfs(mp, &mp->mnt_stat, p);
216 	vfs_unlock(mp);
217 	return (0);
218 }
219 #endif
220 
221 /*
222  * mp - path - addr in user space of mount point (ie /usr or whatever)
223  * data - addr in user space of mount params including the name of the block
224  * special file to treat as a filesystem.
225  */
226 static int
227 msdosfs_mount(struct mount *mp, char *path, caddr_t data, struct nameidata *ndp,
228 	      struct thread *td)
229 {
230 	struct vnode *devvp;	  /* vnode for blk device to mount */
231 	struct msdosfs_args args; /* will hold data from mount request */
232 	/* msdosfs specific mount control block */
233 	struct msdosfsmount *pmp = NULL;
234 	size_t size;
235 	int error, flags;
236 	mode_t accessmode;
237 	struct proc *p = td->td_proc;
238 
239 	KKASSERT(p);
240 
241 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
242 	if (error)
243 		return (error);
244 	if (args.magic != MSDOSFS_ARGSMAGIC)
245 		args.flags = 0;
246 	/*
247 	 * If updating, check whether changing from read-only to
248 	 * read/write; if there is no device name, that's all we do.
249 	 */
250 	if (mp->mnt_flag & MNT_UPDATE) {
251 		pmp = VFSTOMSDOSFS(mp);
252 		error = 0;
253 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
254 			flags = WRITECLOSE;
255 			if (mp->mnt_flag & MNT_FORCE)
256 				flags |= FORCECLOSE;
257 			error = vflush(mp, 0, flags);
258 		}
259 		if (!error && (mp->mnt_flag & MNT_RELOAD))
260 			/* not yet implemented */
261 			error = EOPNOTSUPP;
262 		if (error)
263 			return (error);
264 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
265 			/*
266 			 * If upgrade to read-write by non-root, then verify
267 			 * that user has necessary permissions on the device.
268 			 */
269 			if (p->p_ucred->cr_uid != 0) {
270 				devvp = pmp->pm_devvp;
271 				vn_lock(devvp, NULL, LK_EXCLUSIVE | LK_RETRY, td);
272 				error = VOP_ACCESS(devvp, VREAD | VWRITE,
273 						   p->p_ucred, td);
274 				if (error) {
275 					VOP_UNLOCK(devvp, NULL, 0, td);
276 					return (error);
277 				}
278 				VOP_UNLOCK(devvp, NULL, 0, td);
279 			}
280 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
281 		}
282 		if (args.fspec == 0) {
283 #ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
284 			if (args.flags & MSDOSFSMNT_MNTOPT) {
285 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
286 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
287 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
288 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
289 			}
290 #endif
291 			/*
292 			 * Process export requests.
293 			 */
294 			return (vfs_export(mp, &pmp->pm_export, &args.export));
295 		}
296 	}
297 	/*
298 	 * Not an update, or updating the name: look up the name
299 	 * and verify that it refers to a sensible block device.
300 	 */
301 	NDINIT(ndp, NAMEI_LOOKUP, CNP_FOLLOW, UIO_USERSPACE, args.fspec, td);
302 	error = namei(ndp);
303 	if (error)
304 		return (error);
305 	devvp = ndp->ni_vp;
306 	NDFREE(ndp, NDF_ONLY_PNBUF);
307 
308 	if (!vn_isdisk(devvp, &error)) {
309 		vrele(devvp);
310 		return (error);
311 	}
312 	/*
313 	 * If mount by non-root, then verify that user has necessary
314 	 * permissions on the device.
315 	 */
316 	if (p->p_ucred->cr_uid != 0) {
317 		accessmode = VREAD;
318 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
319 			accessmode |= VWRITE;
320 		vn_lock(devvp, NULL, LK_EXCLUSIVE | LK_RETRY, td);
321 		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, td);
322 		if (error) {
323 			vput(devvp);
324 			return (error);
325 		}
326 		VOP_UNLOCK(devvp, NULL, 0, td);
327 	}
328 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
329 		error = mountmsdosfs(devvp, mp, td, &args);
330 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
331 		pmp = VFSTOMSDOSFS(mp);
332 #endif
333 	} else {
334 		if (devvp != pmp->pm_devvp)
335 			error = EINVAL;	/* XXX needs translation */
336 		else
337 			vrele(devvp);
338 	}
339 	if (error) {
340 		vrele(devvp);
341 		return (error);
342 	}
343 
344 	error = update_mp(mp, &args);
345 	if (error) {
346 		msdosfs_unmount(mp, MNT_FORCE, td);
347 		return error;
348 	}
349 
350 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
351 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
352 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
353 	    &size);
354 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
355 	(void) msdosfs_statfs(mp, &mp->mnt_stat, td);
356 #ifdef MSDOSFS_DEBUG
357 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
358 #endif
359 	return (0);
360 }
361 
362 static int
363 mountmsdosfs(struct vnode *devvp, struct mount *mp, struct thread *td,
364 	     struct msdosfs_args *argp)
365 {
366 	struct msdosfsmount *pmp;
367 	struct buf *bp;
368 	dev_t dev;
369 #ifndef __DragonFly__
370 	struct partinfo dpart;
371 	int bsize = 0, dtype = 0, tmp;
372 #endif
373 	union bootsector *bsp;
374 	struct byte_bpb33 *b33;
375 	struct byte_bpb50 *b50;
376 	struct byte_bpb710 *b710;
377 	u_int8_t SecPerClust;
378 	u_long clusters;
379 	int	ronly, error;
380 
381 	/*
382 	 * Disallow multiple mounts of the same device.
383 	 * Disallow mounting of a device that is currently in use
384 	 * (except for root, which might share swap device for miniroot).
385 	 * Flush out any old buffers remaining from a previous use.
386 	 */
387 	error = vfs_mountedon(devvp);
388 	if (error)
389 		return (error);
390 	if (count_udev(devvp->v_udev) > 0 && devvp != rootvp)
391 		return (EBUSY);
392 	vn_lock(devvp, NULL, LK_EXCLUSIVE | LK_RETRY, td);
393 	error = vinvalbuf(devvp, V_SAVE, td, 0, 0);
394 	VOP_UNLOCK(devvp, NULL, 0, td);
395 	if (error)
396 		return (error);
397 
398 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
399 	vn_lock(devvp, NULL, LK_EXCLUSIVE | LK_RETRY, td);
400 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, td);
401 	VOP_UNLOCK(devvp, NULL, 0, td);
402 	if (error)
403 		return (error);
404 	dev = devvp->v_rdev;
405 	bp  = NULL; /* both used in error_exit */
406 	pmp = NULL;
407 
408 #ifndef __DragonFly__
409 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
410 		/*
411 	 	 * We need the disklabel to calculate the size of a FAT entry
412 		 * later on. Also make sure the partition contains a filesystem
413 		 * of type FS_MSDOS. This doesn't work for floppies, so we have
414 		 * to check for them too.
415 	 	 *
416 	 	 * At least some parts of the msdos fs driver seem to assume
417 		 * that the size of a disk block will always be 512 bytes.
418 		 * Let's check it...
419 		 */
420 		error = VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart, FREAD, td);
421 		if (error)
422 			goto error_exit;
423 		tmp   = dpart.part->p_fstype;
424 		dtype = dpart.disklab->d_type;
425 		bsize = dpart.disklab->d_secsize;
426 		if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
427 			error = EINVAL;
428 			goto error_exit;
429 		}
430 	}
431 #endif
432 
433 	/*
434 	 * Read the boot sector of the filesystem, and then check the
435 	 * boot signature.  If not a dos boot sector then error out.
436 	 *
437 	 * NOTE: 2048 is a maximum sector size in current...
438 	 */
439 	error = bread(devvp, 0, 2048, &bp);
440 	if (error)
441 		goto error_exit;
442 	bp->b_flags |= B_AGE;
443 	bsp = (union bootsector *)bp->b_data;
444 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
445 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
446 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
447 
448 #ifndef __DragonFly__
449 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
450 #endif
451 #ifndef MSDOSFS_NOCHECKSIG
452 		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
453 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
454 			error = EINVAL;
455 			goto error_exit;
456 		}
457 #endif
458 #ifndef __DragonFly__
459 	}
460 #endif
461 
462 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
463 	bzero((caddr_t)pmp, sizeof *pmp);
464 	pmp->pm_mountp = mp;
465 
466 	/*
467 	 * Compute several useful quantities from the bpb in the
468 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
469 	 * the fields that are different between dos 5 and dos 3.3.
470 	 */
471 	SecPerClust = b50->bpbSecPerClust;
472 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
473 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
474 	pmp->pm_FATs = b50->bpbFATs;
475 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
476 	pmp->pm_Sectors = getushort(b50->bpbSectors);
477 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
478 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
479 	pmp->pm_Heads = getushort(b50->bpbHeads);
480 	pmp->pm_Media = b50->bpbMedia;
481 
482 	/* calculate the ratio of sector size to DEV_BSIZE */
483 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
484 
485 #ifndef __DragonFly__
486 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
487 #endif
488 		/* XXX - We should probably check more values here */
489 		if (!pmp->pm_BytesPerSec || !SecPerClust
490 			|| !pmp->pm_Heads
491 #ifdef PC98
492 	    		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
493 #else
494 			|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
495 #endif
496 			error = EINVAL;
497 			goto error_exit;
498 		}
499 #ifndef __DragonFly__
500 	}
501 #endif
502 
503 	if (pmp->pm_Sectors == 0) {
504 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
505 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
506 	} else {
507 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
508 		pmp->pm_HugeSectors = pmp->pm_Sectors;
509 	}
510 	if (pmp->pm_HugeSectors > 0xffffffff /
511 	    (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
512 		/*
513 		 * We cannot deal currently with this size of disk
514 		 * due to fileid limitations (see msdosfs_getattr and
515 		 * msdosfs_readdir)
516 		 */
517 		error = EINVAL;
518 		printf("mountmsdosfs(): disk too big, sorry\n");
519 		goto error_exit;
520 	}
521 
522 	if (pmp->pm_RootDirEnts == 0) {
523 		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
524 		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
525 		    || pmp->pm_Sectors
526 		    || pmp->pm_FATsecs
527 		    || getushort(b710->bpbFSVers)) {
528 			error = EINVAL;
529 			printf("mountmsdosfs(): bad FAT32 filesystem\n");
530 			goto error_exit;
531 		}
532 		pmp->pm_fatmask = FAT32_MASK;
533 		pmp->pm_fatmult = 4;
534 		pmp->pm_fatdiv = 1;
535 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
536 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
537 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
538 		else
539 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
540 	} else
541 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
542 
543 	/*
544 	 * Check a few values (could do some more):
545 	 * - logical sector size: power of 2, >= block size
546 	 * - sectors per cluster: power of 2, >= 1
547 	 * - number of sectors:   >= 1, <= size of partition
548 	 */
549 	if ( (SecPerClust == 0)
550 	  || (SecPerClust & (SecPerClust - 1))
551 	  || (pmp->pm_BytesPerSec < DEV_BSIZE)
552 	  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
553 	  || (pmp->pm_HugeSectors == 0)
554 	) {
555 		error = EINVAL;
556 		goto error_exit;
557 	}
558 
559 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
560 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
561 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
562 	SecPerClust         *= pmp->pm_BlkPerSec;
563 
564 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
565 
566 	if (FAT32(pmp)) {
567 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
568 		pmp->pm_firstcluster = pmp->pm_fatblk
569 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
570 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
571 	} else {
572 		pmp->pm_rootdirblk = pmp->pm_fatblk +
573 			(pmp->pm_FATs * pmp->pm_FATsecs);
574 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
575 				       + DEV_BSIZE - 1)
576 			/ DEV_BSIZE; /* in blocks */
577 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
578 	}
579 
580 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
581 	    SecPerClust + 1;
582 	pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
583 
584 #ifndef __DragonFly__
585 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
586 		if ((pmp->pm_maxcluster <= (0xff0 - 2))
587 		      && ((dtype == DTYPE_FLOPPY) || ((dtype == DTYPE_VNODE)
588 		      && ((pmp->pm_Heads == 1) || (pmp->pm_Heads == 2))))
589 		    ) {
590 			pmp->pm_fatmask = FAT12_MASK;
591 			pmp->pm_fatmult = 3;
592 			pmp->pm_fatdiv = 2;
593 		} else {
594 			pmp->pm_fatmask = FAT16_MASK;
595 			pmp->pm_fatmult = 2;
596 			pmp->pm_fatdiv = 1;
597 		}
598 	} else
599 #endif
600 	if (pmp->pm_fatmask == 0) {
601 		if (pmp->pm_maxcluster
602 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
603 			/*
604 			 * This will usually be a floppy disk. This size makes
605 			 * sure that one fat entry will not be split across
606 			 * multiple blocks.
607 			 */
608 			pmp->pm_fatmask = FAT12_MASK;
609 			pmp->pm_fatmult = 3;
610 			pmp->pm_fatdiv = 2;
611 		} else {
612 			pmp->pm_fatmask = FAT16_MASK;
613 			pmp->pm_fatmult = 2;
614 			pmp->pm_fatdiv = 1;
615 		}
616 	}
617 
618 	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
619 	if (pmp->pm_maxcluster >= clusters) {
620 		printf("Warning: number of clusters (%ld) exceeds FAT "
621 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
622 		pmp->pm_maxcluster = clusters - 1;
623 	}
624 
625 
626 	if (FAT12(pmp))
627 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
628 	else
629 		pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
630 
631 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
632 	pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
633 
634 	/*
635 	 * Compute mask and shift value for isolating cluster relative byte
636 	 * offsets and cluster numbers from a file offset.
637 	 */
638 	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
639 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
640 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
641 
642 	/*
643 	 * Check for valid cluster size
644 	 * must be a power of 2
645 	 */
646 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
647 		error = EINVAL;
648 		goto error_exit;
649 	}
650 
651 	/*
652 	 * Release the bootsector buffer.
653 	 */
654 	brelse(bp);
655 	bp = NULL;
656 
657 	/*
658 	 * Check FSInfo.
659 	 */
660 	if (pmp->pm_fsinfo) {
661 		struct fsinfo *fp;
662 
663 		if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp), &bp)) != 0)
664 			goto error_exit;
665 		fp = (struct fsinfo *)bp->b_data;
666 		if (!bcmp(fp->fsisig1, "RRaA", 4)
667 		    && !bcmp(fp->fsisig2, "rrAa", 4)
668 		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
669 		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4)) {
670 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
671 			if (pmp->pm_nxtfree == 0xffffffff)
672 				pmp->pm_nxtfree = CLUST_FIRST;
673 		} else
674 			pmp->pm_fsinfo = 0;
675 		brelse(bp);
676 		bp = NULL;
677 	}
678 
679 	/*
680 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
681 	 */
682 	if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
683 		printf(
684 		"Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
685 		    pmp->pm_nxtfree, pmp->pm_maxcluster);
686 		error = EINVAL;
687 		goto error_exit;
688 	}
689 
690 	/*
691 	 * Allocate memory for the bitmap of allocated clusters, and then
692 	 * fill it in.
693 	 */
694 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
695 				   / N_INUSEBITS)
696 				  * sizeof(*pmp->pm_inusemap),
697 				  M_MSDOSFSFAT, M_WAITOK);
698 
699 	/*
700 	 * fillinusemap() needs pm_devvp.
701 	 */
702 	pmp->pm_dev = dev;
703 	pmp->pm_devvp = devvp;
704 
705 	/*
706 	 * Have the inuse map filled in.
707 	 */
708 	if ((error = fillinusemap(pmp)) != 0)
709 		goto error_exit;
710 
711 	/*
712 	 * If they want fat updates to be synchronous then let them suffer
713 	 * the performance degradation in exchange for the on disk copy of
714 	 * the fat being correct just about all the time.  I suppose this
715 	 * would be a good thing to turn on if the kernel is still flakey.
716 	 */
717 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
718 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
719 
720 	/*
721 	 * Finish up.
722 	 */
723 	if (ronly)
724 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
725 	else
726 		pmp->pm_fmod = 1;
727 	mp->mnt_data = (qaddr_t) pmp;
728 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
729 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
730 	mp->mnt_flag |= MNT_LOCAL;
731 	vfs_add_vnodeops(&mp->mnt_vn_ops, msdosfs_vnodeop_entries);
732 	dev->si_mountpoint = mp;
733 
734 	return 0;
735 
736 error_exit:
737 	if (bp)
738 		brelse(bp);
739 	(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, td);
740 	if (pmp) {
741 		if (pmp->pm_inusemap)
742 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
743 		free(pmp, M_MSDOSFSMNT);
744 		mp->mnt_data = (qaddr_t)0;
745 	}
746 	return (error);
747 }
748 
749 /*
750  * Unmount the filesystem described by mp.
751  */
752 static int
753 msdosfs_unmount(struct mount *mp, int mntflags, struct thread *td)
754 {
755 	struct msdosfsmount *pmp;
756 	int error, flags;
757 
758 	flags = 0;
759 	if (mntflags & MNT_FORCE)
760 		flags |= FORCECLOSE;
761 	error = vflush(mp, 0, flags);
762 	if (error)
763 		return error;
764 	pmp = VFSTOMSDOSFS(mp);
765 	pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
766 #ifdef MSDOSFS_DEBUG
767 	{
768 		struct vnode *vp = pmp->pm_devvp;
769 
770 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
771 		printf("flag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
772 		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
773 		printf("id %lu, mount %p, op %p\n",
774 		    vp->v_id, vp->v_mount, vp->v_op);
775 		printf("freef %p, freeb %p, mount %p\n",
776 		    TAILQ_NEXT(vp, v_freelist), TAILQ_PREV(vp, v_freelist),
777 		    vp->v_mount);
778 		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
779 		    TAILQ_FIRST(&vp->v_cleanblkhd),
780 		    TAILQ_FIRST(&vp->v_dirtyblkhd),
781 		    vp->v_numoutput, vp->v_type);
782 		printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
783 		    vp->v_socket, vp->v_tag,
784 		    ((u_int *)vp->v_data)[0],
785 		    ((u_int *)vp->v_data)[1]);
786 	}
787 #endif
788 	error = VOP_CLOSE(pmp->pm_devvp,
789 		    (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
790 		    td);
791 	vrele(pmp->pm_devvp);
792 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
793 	free(pmp, M_MSDOSFSMNT);
794 	mp->mnt_data = (qaddr_t)0;
795 	mp->mnt_flag &= ~MNT_LOCAL;
796 	return (error);
797 }
798 
799 static int
800 msdosfs_root(struct mount *mp, struct vnode **vpp)
801 {
802 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
803 	struct denode *ndep;
804 	int error;
805 
806 #ifdef MSDOSFS_DEBUG
807 	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
808 #endif
809 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
810 	if (error)
811 		return (error);
812 	*vpp = DETOV(ndep);
813 	return (0);
814 }
815 
816 static int
817 msdosfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
818 {
819 	struct msdosfsmount *pmp;
820 
821 	pmp = VFSTOMSDOSFS(mp);
822 	sbp->f_bsize = pmp->pm_bpcluster;
823 	sbp->f_iosize = pmp->pm_bpcluster;
824 	sbp->f_blocks = pmp->pm_maxcluster + 1;
825 	sbp->f_bfree = pmp->pm_freeclustercount;
826 	sbp->f_bavail = pmp->pm_freeclustercount;
827 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
828 	sbp->f_ffree = 0;	/* what to put in here? */
829 	if (sbp != &mp->mnt_stat) {
830 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
831 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
832 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
833 	}
834 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
835 	return (0);
836 }
837 
838 struct scaninfo {
839 	int rescan;
840 	int allerror;
841 	int waitfor;
842 	thread_t td;
843 };
844 
845 static int msdosfs_sync_scan(struct mount *mp, struct vnode *vp,
846 		lwkt_tokref_t vlock, void *data);
847 
848 static int
849 msdosfs_sync(struct mount *mp, int waitfor, struct thread *td)
850 {
851 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
852 	struct scaninfo scaninfo;
853 	int error;
854 
855 	/*
856 	 * If we ever switch to not updating all of the fats all the time,
857 	 * this would be the place to update them from the first one.
858 	 */
859 	if (pmp->pm_fmod != 0) {
860 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
861 			panic("msdosfs_sync: rofs mod");
862 		else {
863 			/* update fats here */
864 		}
865 	}
866 	/*
867 	 * Write back each (modified) denode.
868 	 */
869 	scaninfo.allerror = 0;
870 	scaninfo.rescan = 1;
871 	scaninfo.td = td;
872 	while (scaninfo.rescan) {
873 		scaninfo.rescan = 0;
874 		vmntvnodescan(mp, NULL, msdosfs_sync_scan, &scaninfo);
875 	}
876 
877 	/*
878 	 * Flush filesystem control info.
879 	 */
880 	if (waitfor != MNT_LAZY) {
881 		vn_lock(pmp->pm_devvp, NULL, LK_EXCLUSIVE | LK_RETRY, td);
882 		if ((error = VOP_FSYNC(pmp->pm_devvp, waitfor, td)) != 0)
883 			scaninfo.allerror = error;
884 		VOP_UNLOCK(pmp->pm_devvp, NULL, 0, td);
885 	}
886 	return (scaninfo.allerror);
887 }
888 
889 static int
890 msdosfs_sync_scan(struct mount *mp, struct vnode *vp,
891 		  lwkt_tokref_t vlock, void *data)
892 {
893 	struct scaninfo *info = data;
894 	struct denode *dep;
895 	int error;
896 
897 	dep = VTODE(vp);
898 	if (vp->v_type == VNON ||
899 	    ((dep->de_flag &
900 	    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
901 	    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || info->waitfor == MNT_LAZY))) {
902 		lwkt_reltoken(vlock);
903 		return(0);
904 	}
905 	error = vget(vp, vlock, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, info->td);
906 	if (error) {
907 		if (error == ENOENT)
908 			info->rescan = 1;
909 		return(0);
910 	}
911 	if ((error = VOP_FSYNC(vp, info->waitfor, info->td)) != 0)
912 		info->allerror = error;
913 	VOP_UNLOCK(vp, NULL, 0, info->td);
914 	vrele(vp);
915 	return(0);
916 }
917 
918 static int
919 msdosfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
920 {
921 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
922 	struct defid *defhp = (struct defid *) fhp;
923 	struct denode *dep;
924 	int error;
925 
926 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
927 	if (error) {
928 		*vpp = NULLVP;
929 		return (error);
930 	}
931 	*vpp = DETOV(dep);
932 	return (0);
933 }
934 
935 static int
936 msdosfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp,
937 		 struct ucred **credanonp)
938 {
939 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
940 	struct netcred *np;
941 
942 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
943 	if (np == NULL)
944 		return (EACCES);
945 	*exflagsp = np->netc_exflags;
946 	*credanonp = &np->netc_anon;
947 	return (0);
948 }
949 
950 static int
951 msdosfs_vptofh(struct vnode *vp, struct fid *fhp)
952 {
953 	struct denode *dep;
954 	struct defid *defhp;
955 
956 	dep = VTODE(vp);
957 	defhp = (struct defid *)fhp;
958 	defhp->defid_len = sizeof(struct defid);
959 	defhp->defid_dirclust = dep->de_dirclust;
960 	defhp->defid_dirofs = dep->de_diroffset;
961 	/* defhp->defid_gen = dep->de_gen; */
962 	return (0);
963 }
964 
965 static struct vfsops msdosfs_vfsops = {
966 	msdosfs_mount,
967 	vfs_stdstart,
968 	msdosfs_unmount,
969 	msdosfs_root,
970 	vfs_stdquotactl,
971 	msdosfs_statfs,
972 	msdosfs_sync,
973 	vfs_stdvget,
974 	msdosfs_fhtovp,
975 	msdosfs_checkexp,
976 	msdosfs_vptofh,
977 	msdosfs_init,
978 	msdosfs_uninit,
979 	vfs_stdextattrctl,
980 };
981 
982 VFS_SET(msdosfs_vfsops, msdos, 0);
983