xref: /dragonfly/sys/vfs/msdosfs/msdosfs_vfsops.c (revision 08e12053)
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/conf.h>
56 #include <sys/proc.h>
57 #include <sys/nlookup.h>
58 #include <sys/kernel.h>
59 #include <sys/vnode.h>
60 #include <sys/iconv.h>
61 #include <sys/mount.h>
62 #include <sys/buf.h>
63 #include <sys/fcntl.h>
64 #include <sys/malloc.h>
65 #include <sys/stat.h>
66 #include <vm/vm_zone.h>
67 
68 #include <sys/buf2.h>
69 
70 #include <vfs/msdosfs/bootsect.h>
71 #include <vfs/msdosfs/bpb.h>
72 #include <vfs/msdosfs/direntry.h>
73 #include <vfs/msdosfs/denode.h>
74 #include <vfs/msdosfs/fat.h>
75 #include <vfs/msdosfs/msdosfsmount.h>
76 
77 extern struct vop_ops msdosfs_vnode_vops;
78 struct iconv_functions *msdosfs_iconv;
79 
80 #define ENCODING_UNICODE        "UTF-16BE"
81 #if 1 /*def PC98*/
82 /*
83  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
84  *       garbage or a random value :-{
85  *       If you want to use that broken-signatured media, define the
86  *       following symbol even though PC/AT.
87  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
88  */
89 #define	MSDOSFS_NOCHECKSIG
90 #endif
91 
92 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
93 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
94 
95 static int mountmsdosfs(struct vnode *devvp, struct mount *mp,
96     struct msdosfs_args *argp);
97 static int msdosfs_root(struct mount *, struct vnode **);
98 static int msdosfs_statfs(struct mount *, struct statfs *, struct ucred *);
99 static int msdosfs_unmount(struct mount *, int);
100 
101 static int
update_mp(struct mount * mp,struct msdosfs_args * argp)102 update_mp(struct mount *mp, struct msdosfs_args *argp)
103 {
104 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
105 	int error;
106 	char cs_local[ICONV_CSNMAXLEN];
107 	char cs_dos[ICONV_CSNMAXLEN];
108 
109 	pmp->pm_gid = argp->gid;
110 	pmp->pm_uid = argp->uid;
111 	pmp->pm_mask = argp->mask & ALLPERMS;
112 	pmp->pm_dirmask = argp->dirmask & ALLPERMS;
113 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
114 
115 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
116 		memcpy(cs_local, argp->cs_local, sizeof(cs_local));
117 		memcpy(cs_dos, argp->cs_dos, sizeof(cs_dos));
118 		kprintf("local: %s dos: %s\n",argp->cs_local, argp->cs_dos);
119 		error = msdosfs_iconv->open(cs_local, ENCODING_UNICODE,
120 					    &pmp->pm_w2u);
121 		if(error)
122 			return error;
123 		error = msdosfs_iconv->open(ENCODING_UNICODE, cs_local,
124 					    &pmp->pm_u2w);
125 		if(error)
126 			return error;
127 		error = msdosfs_iconv->open(cs_dos, cs_local, &pmp->pm_u2d);
128 		if(error)
129 			return error;
130 		error = msdosfs_iconv->open(cs_local, cs_dos, &pmp->pm_d2u);
131 		if(error)
132 			return error;
133 	}
134 
135 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
136 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
137 	else
138 		pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
139 	return 0;
140 }
141 
142 /*
143  * mp - path - addr in user space of mount point (ie /usr or whatever)
144  * data - addr in user space of mount params including the name of the block
145  * special file to treat as a filesystem.
146  */
147 static int
msdosfs_mount(struct mount * mp,char * path,caddr_t data,struct ucred * cred)148 msdosfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
149 {
150 	struct vnode *devvp;	  /* vnode for blk device to mount */
151 	struct msdosfs_args args; /* will hold data from mount request */
152 	/* msdosfs specific mount control block */
153 	struct msdosfsmount *pmp = NULL;
154 	size_t size;
155 	int error, flags;
156 	mode_t accessmode;
157 	struct nlookupdata nd;
158 
159 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
160 	if (error)
161 		return (error);
162 	/*
163 	 * If updating, check whether changing from read-only to
164 	 * read/write; if there is no device name, that's all we do.
165 	 */
166 	if (mp->mnt_flag & MNT_UPDATE) {
167 		pmp = VFSTOMSDOSFS(mp);
168 		error = 0;
169 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
170 		    (mp->mnt_flag & MNT_RDONLY)) {
171 			flags = WRITECLOSE;
172 			if (mp->mnt_flag & MNT_FORCE)
173 				flags |= FORCECLOSE;
174 			error = vflush(mp, 0, flags);
175 			if (error == 0) {
176 				devvp = pmp->pm_devvp;
177 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
178 				VOP_OPEN(devvp, FREAD, FSCRED, NULL);
179 				VOP_CLOSE(devvp, FREAD|FWRITE, NULL);
180 				vn_unlock(devvp);
181 				pmp->pm_flags |= MSDOSFSMNT_RONLY;
182 			}
183 		}
184 		if (!error && (mp->mnt_flag & MNT_RELOAD))
185 			error = EOPNOTSUPP; /* not yet implemented */
186 		if (error)
187 			return (error);
188 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
189 		    (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
190 			/*
191 			 * If upgrade to read-write by non-root, then verify
192 			 * that user has necessary permissions on the device.
193 			 */
194 			devvp = pmp->pm_devvp;
195 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
196 			if (cred->cr_uid != 0) {
197 				error = VOP_EACCESS(devvp, VREAD | VWRITE,
198 						    cred);
199 				if (error) {
200 					vn_unlock(devvp);
201 					return (error);
202 				}
203 			}
204 			VOP_OPEN(devvp, FREAD|FWRITE, FSCRED, NULL);
205 			VOP_CLOSE(devvp, FREAD, NULL);
206 			vn_unlock(devvp);
207 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
208 		}
209 		if (args.fspec == NULL) {
210 #ifdef __notyet__	/* doesn't work correctly with current mountd XXX */
211 			if (args.flags & MSDOSFSMNT_MNTOPT) {
212 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
213 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
214 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
215 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
216 			}
217 #endif
218 			/*
219 			 * Process export requests.
220 			 */
221 			return (vfs_export(mp, &pmp->pm_export, &args.export));
222 		}
223 	}
224 	/*
225 	 * Not an update, or updating the name: look up the name
226 	 * and verify that it refers to a sensible disk device.
227 	 */
228 	devvp = NULL;
229 	error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
230 	if (error == 0)
231 		error = nlookup(&nd);
232 	if (error == 0)
233 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
234 	nlookup_done(&nd);
235 	if (error)
236 		return (error);
237 
238 	if (!vn_isdisk(devvp, &error)) {
239 		vrele(devvp);
240 		return (error);
241 	}
242 	/*
243 	 * If mount by non-root, then verify that user has necessary
244 	 * permissions on the device.
245 	 */
246 	if (cred->cr_uid != 0) {
247 		accessmode = VREAD;
248 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
249 			accessmode |= VWRITE;
250 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
251 		error = VOP_EACCESS(devvp, accessmode, cred);
252 		if (error) {
253 			vput(devvp);
254 			return (error);
255 		}
256 		vn_unlock(devvp);
257 	}
258 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
259 		error = mountmsdosfs(devvp, mp, &args);
260 #ifdef MSDOSFS_DEBUG		/* only needed for the kprintf below */
261 		pmp = VFSTOMSDOSFS(mp);
262 #endif
263 	} else {
264 		if (devvp != pmp->pm_devvp)
265 			error = EINVAL;	/* XXX needs translation */
266 		else
267 			vrele(devvp);
268 	}
269 	if (error) {
270 		vrele(devvp);
271 		return (error);
272 	}
273 
274 	error = update_mp(mp, &args);
275 	if (error) {
276 		if ((mp->mnt_flag & MNT_UPDATE) == 0)
277 			msdosfs_unmount(mp, MNT_FORCE);
278 		return error;
279 	}
280 
281 	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
282 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
283 	msdosfs_statfs(mp, &mp->mnt_stat, cred);
284 #ifdef MSDOSFS_DEBUG
285 	kprintf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n",
286 		mp, pmp, pmp->pm_inusemap);
287 #endif
288 	return (0);
289 }
290 
291 static int
mountmsdosfs(struct vnode * devvp,struct mount * mp,struct msdosfs_args * argp)292 mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
293 {
294 	struct msdosfsmount *pmp;
295 	struct buf *bp;
296 	cdev_t dev;
297 	union bootsector *bsp;
298 	struct byte_bpb33 *b33;
299 	struct byte_bpb50 *b50;
300 	struct byte_bpb710 *b710;
301 	uint8_t SecPerClust;
302 	u_long clusters;
303 	int ronly, error;
304 
305 	/*
306 	 * Disallow multiple mounts of the same device.
307 	 * Disallow mounting of a device that is currently in use
308 	 * Flush out any old buffers remaining from a previous use.
309 	 */
310 	error = vfs_mountedon(devvp);
311 	if (error)
312 		return (error);
313 	if (vcount(devvp) > 0)
314 		return (EBUSY);
315 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
316 	error = vinvalbuf(devvp, V_SAVE, 0, 0);
317 	vn_unlock(devvp);
318 	if (error)
319 		return (error);
320 
321 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
322 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
323 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, NULL);
324 	vn_unlock(devvp);
325 	if (error)
326 		return (error);
327 	dev = devvp->v_rdev;
328 	bp  = NULL; /* both used in error_exit */
329 	pmp = NULL;
330 
331 	/*
332 	 * Read the boot sector of the filesystem, and then check the
333 	 * boot signature.  If not a dos boot sector then error out.
334 	 *
335 	 * NOTE: 8192 is a magic size that works for ffs.
336 	 */
337 	error = bread(devvp, 0, 8192, &bp);
338 	if (error)
339 		goto error_exit;
340 	bp->b_flags |= B_AGE;
341 	bsp = (union bootsector *)bp->b_data;
342 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
343 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
344 	b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
345 
346 #ifndef MSDOSFS_NOCHECKSIG
347 	if (bsp->bs50.bsBootSectSig0 != BOOTSIG0 ||
348 	    bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
349 		error = EINVAL;
350 		goto error_exit;
351 	}
352 #endif
353 
354 	pmp = kmalloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK | M_ZERO);
355 	pmp->pm_mountp = mp;
356 
357 	/*
358 	 * Compute several useful quantities from the bpb in the
359 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
360 	 * the fields that are different between dos 5 and dos 3.3.
361 	 */
362 	SecPerClust = b50->bpbSecPerClust;
363 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
364 	if (pmp->pm_BytesPerSec < DEV_BSIZE) {
365 		error = EINVAL;
366 		goto error_exit;
367 	}
368 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
369 	pmp->pm_FATs = b50->bpbFATs;
370 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
371 	pmp->pm_Sectors = getushort(b50->bpbSectors);
372 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
373 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
374 	pmp->pm_Heads = getushort(b50->bpbHeads);
375 	pmp->pm_Media = b50->bpbMedia;
376 
377 	/* calculate the ratio of sector size to DEV_BSIZE */
378 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
379 
380 	/*
381 	 * We don't check pm_Heads nor pm_SecPerTrack, because
382 	 * these may not be set for EFI file systems. We don't
383 	 * use these anyway, so we're unaffected if they are
384 	 * invalid.
385 	 */
386 	if (pmp->pm_BytesPerSec == 0 || SecPerClust == 0) {
387 		error = EINVAL;
388 		goto error_exit;
389 	}
390 
391 	if (pmp->pm_Sectors == 0) {
392 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
393 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
394 	} else {
395 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
396 		pmp->pm_HugeSectors = pmp->pm_Sectors;
397 	}
398 
399 	if (pmp->pm_RootDirEnts == 0) {
400 		if (pmp->pm_FATsecs != 0 || getushort(b710->bpbFSVers) != 0) {
401 			error = EINVAL;
402 			kprintf("mountmsdosfs(): bad FAT32 filesystem\n");
403 			goto error_exit;
404 		}
405 		pmp->pm_fatmask = FAT32_MASK;
406 		pmp->pm_fatmult = 4;
407 		pmp->pm_fatdiv = 1;
408 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
409 		if ((getushort(b710->bpbExtFlags) & FATMIRROR) != 0)
410 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
411 		else
412 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
413 	} else
414 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
415 
416 	/*
417 	 * Check a few values (could do some more):
418 	 * - logical sector size: power of 2, >= block size
419 	 * - sectors per cluster: power of 2, >= 1
420 	 * - number of sectors:   >= 1, <= size of partition
421 	 * - number of FAT sectors: >= 1
422 	 */
423 	if (SecPerClust == 0 || (SecPerClust & (SecPerClust - 1)) != 0 ||
424 	    pmp->pm_BytesPerSec < DEV_BSIZE ||
425 	    (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1)) != 0 ||
426 	    pmp->pm_HugeSectors == 0 || pmp->pm_FATsecs == 0 ||
427 	    SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE) {
428 		error = EINVAL;
429 		goto error_exit;
430 	}
431 
432 	if ((off_t)pmp->pm_HugeSectors * pmp->pm_BytesPerSec <
433 	    pmp->pm_HugeSectors /* overflow */) {
434 		/* XXX FreeBSD also checks media size in above */
435 		error = EINVAL;
436 		goto error_exit;
437 	}
438 
439 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
440 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec;	/* XXX not used? */
441 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
442 	SecPerClust         *= pmp->pm_BlkPerSec;
443 
444 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
445 
446 	if (FAT32(pmp)) {
447 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
448 		pmp->pm_firstcluster = pmp->pm_fatblk +
449 		    pmp->pm_FATs * pmp->pm_FATsecs;
450 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
451 	} else {
452 		pmp->pm_rootdirblk = pmp->pm_fatblk +
453 		    pmp->pm_FATs * pmp->pm_FATsecs;
454 		pmp->pm_rootdirsize = howmany(pmp->pm_RootDirEnts *
455 		    sizeof(struct direntry), DEV_BSIZE); /* in blocks */
456 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
457 	}
458 
459 	if (pmp->pm_HugeSectors <= pmp->pm_firstcluster) {
460 		error = EINVAL;
461 		goto error_exit;
462 	}
463 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
464 	    SecPerClust + 1;
465 
466 	if (pmp->pm_fatmask == 0) {
467 		if (pmp->pm_maxcluster <= ((CLUST_RSRVD - CLUST_FIRST) &
468 		    FAT12_MASK)) {
469 			/*
470 			 * This will usually be a floppy disk. This size makes
471 			 * sure that one FAT entry will not be split across
472 			 * multiple blocks.
473 			 */
474 			pmp->pm_fatmask = FAT12_MASK;
475 			pmp->pm_fatmult = 3;
476 			pmp->pm_fatdiv = 2;
477 		} else {
478 			pmp->pm_fatmask = FAT16_MASK;
479 			pmp->pm_fatmult = 2;
480 			pmp->pm_fatdiv = 1;
481 		}
482 	}
483 
484 	clusters = ((pmp->pm_FATsecs * DEV_BSIZE) / pmp->pm_fatmult) *
485 		pmp->pm_fatdiv;
486 	if (pmp->pm_maxcluster >= clusters) {
487 		kprintf("Warning: number of clusters (%ld) exceeds FAT "
488 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
489 		pmp->pm_maxcluster = clusters - 1;
490 	}
491 
492 	if (FAT12(pmp))
493 		pmp->pm_fatblocksize = 3 * 512;
494 	else
495 		pmp->pm_fatblocksize = PAGE_SIZE;
496 	pmp->pm_fatblocksize = roundup(pmp->pm_fatblocksize,
497 	    pmp->pm_BytesPerSec);
498 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
499 	pmp->pm_bnshift = DEV_BSHIFT;
500 
501 	/*
502 	 * Compute mask and shift value for isolating cluster relative byte
503 	 * offsets and cluster numbers from a file offset.
504 	 */
505 	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
506 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
507 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
508 
509 	/*
510 	 * Check for valid cluster size
511 	 * must be a power of 2
512 	 */
513 	if ((pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) != 0) {
514 		error = EINVAL;
515 		goto error_exit;
516 	}
517 
518 	/*
519 	 * Release the bootsector buffer.
520 	 */
521 	bp->b_flags |= B_RELBUF;
522 	brelse(bp);
523 	bp = NULL;
524 
525 	/*
526 	 * Check the fsinfo sector if we have one.  Silently fix up our
527 	 * in-core copy of fp->fsinxtfree if it is unknown (0xffffffff)
528 	 * or too large.  Ignore fp->fsinfree for now, since we need to
529 	 * read the entire FAT anyway to fill the inuse map.
530 	 */
531 	if (pmp->pm_fsinfo) {
532 		struct fsinfo *fp;
533 
534 		if ((error = bread(devvp, de_bn2doff(pmp, pmp->pm_fsinfo),
535 		    pmp->pm_BytesPerSec, &bp)) != 0)
536 			goto error_exit;
537 		fp = (struct fsinfo *)bp->b_data;
538 		if (!memcmp(fp->fsisig1, "RRaA", 4) &&
539 		    !memcmp(fp->fsisig2, "rrAa", 4) &&
540 		    !memcmp(fp->fsisig3, "\0\0\125\252", 4)) {
541 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
542 			if (pmp->pm_nxtfree > pmp->pm_maxcluster)
543 				pmp->pm_nxtfree = CLUST_FIRST;
544 		} else
545 			pmp->pm_fsinfo = 0;
546 		bp->b_flags |= B_RELBUF;
547 		brelse(bp);
548 		bp = NULL;
549 	}
550 
551 	/*
552 	 * Finish initializing pmp->pm_nxtfree (just in case the first few
553 	 * sectors aren't properly reserved in the FAT).  This completes
554 	 * the fixup for fp->fsinxtfree, and fixes up the zero-initialized
555 	 * value if there is no fsinfo.  We will use pmp->pm_nxtfree
556 	 * internally even if there is no fsinfo.
557 	 */
558 	if (pmp->pm_nxtfree < CLUST_FIRST)
559 		pmp->pm_nxtfree = CLUST_FIRST;
560 
561 	/*
562 	 * Allocate memory for the bitmap of allocated clusters, and then
563 	 * fill it in.
564 	 */
565 	pmp->pm_inusemap = kmalloc(howmany(pmp->pm_maxcluster + 1,
566 	    N_INUSEBITS) * sizeof(*pmp->pm_inusemap), M_MSDOSFSFAT, M_WAITOK);
567 
568 	/*
569 	 * fillinusemap() needs pm_devvp.
570 	 */
571 	pmp->pm_devvp = devvp;
572 	pmp->pm_dev = dev;
573 
574 	/*
575 	 * Have the inuse map filled in.
576 	 */
577 	MSDOSFS_LOCK_MP(pmp);
578 	error = fillinusemap(pmp);
579 	MSDOSFS_UNLOCK_MP(pmp);
580 	if (error != 0)
581 		goto error_exit;
582 
583 	/*
584 	 * If they want FAT updates to be synchronous then let them suffer
585 	 * the performance degradation in exchange for the on disk copy of
586 	 * the FAT being correct just about all the time.  I suppose this
587 	 * would be a good thing to turn on if the kernel is still flakey.
588 	 */
589 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
590 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
591 
592 	/*
593 	 * Finish up.
594 	 */
595 	if (ronly)
596 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
597 	else
598 		pmp->pm_fmod = 1;
599 	mp->mnt_data = (qaddr_t) pmp;
600 	mp->mnt_stat.f_fsid.val[0] = devid_from_dev(dev);
601 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
602 	mp->mnt_flag |= MNT_LOCAL;
603 	vfs_add_vnodeops(mp, &msdosfs_vnode_vops, &mp->mnt_vn_norm_ops);
604 	dev->si_mountpoint = mp;
605 
606 	return (0);
607 
608 error_exit:
609 	if (bp != NULL) {
610 		bp->b_flags |= B_RELBUF;
611 		brelse(bp);
612 	}
613 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
614 	VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NULL);
615 	vn_unlock(devvp);
616 	if (pmp != NULL) {
617 		if (pmp->pm_inusemap)
618 			kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
619 		kfree(pmp, M_MSDOSFSMNT);
620 		mp->mnt_data = (qaddr_t)0;
621 	}
622 	return (error);
623 }
624 
625 /*
626  * Unmount the filesystem described by mp.
627  */
628 static int
msdosfs_unmount(struct mount * mp,int mntflags)629 msdosfs_unmount(struct mount *mp, int mntflags)
630 {
631 	struct msdosfsmount *pmp;
632 	int error, flags;
633 #ifdef MSDOSFS_DEBUG
634 	struct vnode *vp;
635 #endif
636 	flags = 0;
637 	if (mntflags & MNT_FORCE)
638 		flags |= FORCECLOSE;
639 	error = vflush(mp, 0, flags);
640 	if (error)
641 		return error;
642 
643 	pmp = VFSTOMSDOSFS(mp);
644 	pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
645 
646 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
647 		if (pmp->pm_w2u)
648 			msdosfs_iconv->close(pmp->pm_w2u);
649 		if (pmp->pm_u2w)
650 			msdosfs_iconv->close(pmp->pm_u2w);
651 		if (pmp->pm_d2u)
652 			msdosfs_iconv->close(pmp->pm_d2u);
653 		if (pmp->pm_u2d)
654 			msdosfs_iconv->close(pmp->pm_u2d);
655 	}
656 
657 #ifdef MSDOSFS_DEBUG
658 	vp = pmp->pm_devvp;
659 	kprintf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
660 	kprintf("flag %08x, refcnt 0x%08x, writecount %d, auxrefs 0x%08x\n",
661 		vp->v_flag, vp->v_refcnt, vp->v_writecount, vp->v_auxrefs);
662 	kprintf("mount %p, op %p\n", vp->v_mount, vp->v_ops);
663 	kprintf("mount %p\n", vp->v_mount);
664 	kprintf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
665 		RB_ROOT(&vp->v_rbclean_tree), RB_ROOT(&vp->v_rbdirty_tree),
666 		bio_track_active(&vp->v_track_write), vp->v_type);
667 	kprintf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
668 		vp->v_socket, vp->v_tag, ((u_int *)vp->v_data)[0],
669 		((u_int *)vp->v_data)[1]);
670 #endif
671 
672 	vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
673 	error = VOP_CLOSE(pmp->pm_devvp,
674 		    pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD | FWRITE,
675 		    NULL);
676 	vn_unlock(pmp->pm_devvp);
677 	vrele(pmp->pm_devvp);
678 	kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
679 	kfree(pmp, M_MSDOSFSMNT);
680 	mp->mnt_data = (qaddr_t)0;
681 	mp->mnt_flag &= ~MNT_LOCAL;
682 	return (error);
683 }
684 
685 static int
msdosfs_root(struct mount * mp,struct vnode ** vpp)686 msdosfs_root(struct mount *mp, struct vnode **vpp)
687 {
688 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
689 	struct denode *ndep;
690 	int error;
691 
692 	mprintf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
693 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
694 	if (error)
695 		return (error);
696 	*vpp = DETOV(ndep);
697 	return (0);
698 }
699 
700 static int
msdosfs_statfs(struct mount * mp,struct statfs * sbp,struct ucred * cred)701 msdosfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
702 {
703 	struct msdosfsmount *pmp;
704 
705 	pmp = VFSTOMSDOSFS(mp);
706 	sbp->f_bsize = pmp->pm_bpcluster;
707 	sbp->f_iosize = pmp->pm_bpcluster;
708 	sbp->f_blocks = pmp->pm_maxcluster + 1;
709 	sbp->f_bfree = pmp->pm_freeclustercount;
710 	sbp->f_bavail = pmp->pm_freeclustercount;
711 	sbp->f_files = pmp->pm_RootDirEnts;	/* XXX */
712 	sbp->f_ffree = 0;	/* what to put in here? */
713 	if (sbp != &mp->mnt_stat) {
714 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
715 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
716 	}
717 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
718 	return (0);
719 }
720 
721 static int
msdosfs_statvfs(struct mount * mp,struct statvfs * sbp,struct ucred * cred)722 msdosfs_statvfs(struct mount *mp, struct statvfs *sbp, struct ucred *cred)
723 {
724 	struct msdosfsmount *pmp;
725 
726 	pmp = VFSTOMSDOSFS(mp);
727 	sbp->f_bsize = pmp->pm_bpcluster;
728 	sbp->f_frsize = pmp->pm_bpcluster;
729 	sbp->f_blocks = pmp->pm_maxcluster + 1;
730 	sbp->f_bfree = pmp->pm_freeclustercount;
731 	sbp->f_bavail = pmp->pm_freeclustercount;
732 	sbp->f_files = pmp->pm_RootDirEnts;	/* XXX */
733 	sbp->f_ffree = 0;	/* what to put in here? */
734 	if (sbp != &mp->mnt_vstat) {
735 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
736 	}
737 	return (0);
738 }
739 
740 struct scaninfo {
741 	int rescan;
742 	int allerror;
743 	int waitfor;
744 };
745 
746 static int msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data);
747 
748 /*
749  * If we have an FSInfo block, update it.
750  */
751 static int
msdosfs_fsiflush(struct msdosfsmount * pmp,int waitfor)752 msdosfs_fsiflush(struct msdosfsmount *pmp, int waitfor)
753 {
754 	struct fsinfo *fp;
755 	struct buf *bp;
756 	int error;
757 
758 	MSDOSFS_LOCK_MP(pmp);
759 	if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) {
760 		error = 0;
761 		goto unlock;
762 	}
763 	error = bread(pmp->pm_devvp, de_bn2doff(pmp, pmp->pm_fsinfo),
764 	    pmp->pm_BytesPerSec, &bp);
765 	if (error != 0) {
766 		brelse(bp);
767 		goto unlock;
768 	}
769 
770 	fp = (struct fsinfo *)bp->b_data;
771 	putulong(fp->fsinfree, pmp->pm_freeclustercount);
772 	putulong(fp->fsinxtfree, pmp->pm_nxtfree);
773 	pmp->pm_flags &= ~MSDOSFS_FSIMOD;
774 	if (waitfor == MNT_WAIT)
775 		error = bwrite(bp);
776 	else
777 		bawrite(bp);
778 unlock:
779 	MSDOSFS_UNLOCK_MP(pmp);
780 	return (error);
781 }
782 
783 static int
msdosfs_sync(struct mount * mp,int waitfor)784 msdosfs_sync(struct mount *mp, int waitfor)
785 {
786 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
787 	struct scaninfo scaninfo;
788 	int error;
789 
790 	/*
791 	 * If we ever switch to not updating all of the FATs all the time,
792 	 * this would be the place to update them from the first one.
793 	 */
794 	if (pmp->pm_fmod != 0) {
795 		if (pmp->pm_flags & MSDOSFSMNT_RONLY) {
796 			panic("msdosfs_sync: rofs mod");
797 		} else {
798 			/* update FATs here */
799 		}
800 	}
801 	/*
802 	 * Write back each (modified) denode.
803 	 */
804 	scaninfo.allerror = 0;
805 	scaninfo.rescan = 1;
806 	while (scaninfo.rescan) {
807 		scaninfo.rescan = 0;
808 		vmntvnodescan(mp, VMSC_GETVP|VMSC_NOWAIT, NULL,
809 			      msdosfs_sync_scan, &scaninfo);
810 	}
811 
812 	/*
813 	 * Flush filesystem control info.
814 	 */
815 	if ((waitfor & MNT_LAZY) == 0) {
816 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
817 		if ((error = VOP_FSYNC(pmp->pm_devvp, waitfor, 0)) != 0)
818 			scaninfo.allerror = error;
819 		vn_unlock(pmp->pm_devvp);
820 	}
821 
822 	error = msdosfs_fsiflush(pmp, waitfor);
823 	if (error != 0)
824 		scaninfo.allerror = error;
825 	return (scaninfo.allerror);
826 }
827 
828 static int
msdosfs_sync_scan(struct mount * mp,struct vnode * vp,void * data)829 msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data)
830 {
831 	struct scaninfo *info = data;
832 	struct denode *dep;
833 	int error;
834 
835 	dep = VTODE(vp);
836 	if (vp->v_type == VNON || vp->v_type == VBAD ||
837 	    ((dep->de_flag &
838 	    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
839 	    (RB_EMPTY(&vp->v_rbdirty_tree) || (info->waitfor & MNT_LAZY)))) {
840 		return(0);
841 	}
842 	if ((error = VOP_FSYNC(vp, info->waitfor, 0)) != 0)
843 		info->allerror = error;
844 	return(0);
845 }
846 
847 static int
msdosfs_fhtovp(struct mount * mp,struct vnode * rootvp,struct fid * fhp,struct vnode ** vpp)848 msdosfs_fhtovp(struct mount *mp, struct vnode *rootvp,
849 	       struct fid *fhp, struct vnode **vpp)
850 {
851 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
852 	struct defid *defhp = (struct defid *) fhp;
853 	struct denode *dep;
854 	int error;
855 
856 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
857 	if (error) {
858 		*vpp = NULLVP;
859 		return (error);
860 	}
861 	*vpp = DETOV(dep);
862 	return (0);
863 }
864 
865 static int
msdosfs_checkexp(struct mount * mp,struct sockaddr * nam,int * exflagsp,struct ucred ** credanonp)866 msdosfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp,
867 		 struct ucred **credanonp)
868 {
869 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
870 	struct netcred *np;
871 
872 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
873 	if (np == NULL)
874 		return (EACCES);
875 	*exflagsp = np->netc_exflags;
876 	*credanonp = &np->netc_anon;
877 	return (0);
878 }
879 
880 static int
msdosfs_vptofh(struct vnode * vp,struct fid * fhp)881 msdosfs_vptofh(struct vnode *vp, struct fid *fhp)
882 {
883 	struct denode *dep;
884 	struct defid *defhp;
885 
886 	dep = VTODE(vp);
887 	defhp = (struct defid *)fhp;
888 	defhp->defid_len = sizeof(struct defid);
889 	defhp->defid_dirclust = dep->de_dirclust;
890 	defhp->defid_dirofs = dep->de_diroffset;
891 	/* defhp->defid_gen = dep->de_gen; */
892 	return (0);
893 }
894 
895 static struct vfsops msdosfs_vfsops = {
896 	.vfs_flags =		0,
897 	.vfs_mount =		msdosfs_mount,
898 	.vfs_root =		msdosfs_root,
899 	.vfs_statfs =		msdosfs_statfs,
900 	.vfs_statvfs =		msdosfs_statvfs,
901 	.vfs_sync =		msdosfs_sync,
902 	.vfs_fhtovp =		msdosfs_fhtovp,
903 	.vfs_checkexp =		msdosfs_checkexp,
904 	.vfs_vptofh =		msdosfs_vptofh,
905 	.vfs_init =		msdosfs_init,
906 	.vfs_uninit =		msdosfs_uninit,
907 	.vfs_unmount =		msdosfs_unmount,
908 };
909 
910 VFS_SET(msdosfs_vfsops, msdos, 0);
911 MODULE_VERSION(msdos, 1);
912