1 /* $NetBSD: msdosfs_lookup.c,v 1.37 1997/11/17 15:36:54 ws Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-4-Clause
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
53 // Modified to support the Haiku FAT driver
54
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/buf.h>
58 #include <sys/mount.h>
59 #include <sys/namei.h>
60 #include <sys/vnode.h>
61
62 #include <fs/msdosfs/bpb.h>
63 #include <fs/msdosfs/direntry.h>
64 #include <fs/msdosfs/denode.h>
65 #include <fs/msdosfs/fat.h>
66 #include <fs/msdosfs/msdosfsmount.h>
67
68 static int
msdosfs_lookup_checker(struct msdosfsmount * pmp,struct vnode * dvp,struct denode * tdp,struct vnode ** vpp)69 msdosfs_lookup_checker(struct msdosfsmount *pmp, struct vnode *dvp,
70 struct denode *tdp, struct vnode **vpp)
71 {
72 struct vnode *vp;
73
74 vp = DETOV(tdp);
75
76 /*
77 * Lookup assumes that directory cannot be hardlinked.
78 * Corrupted msdosfs filesystem could break this assumption.
79 */
80 if (vp == dvp) {
81 vput(vp);
82 msdosfs_integrity_error(pmp);
83 *vpp = NULL;
84 return (EBADF);
85 }
86
87 *vpp = vp;
88 return (0);
89 }
90
91 // Haiku port: unused FreeBSD hook function
92 #if 0
93 int
94 msdosfs_lookup(struct vop_cachedlookup_args *ap)
95 {
96
97 return (msdosfs_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL,
98 NULL));
99 }
100 #endif // 0
101
102 struct deget_dotdot {
103 u_long cluster;
104 int blkoff;
105 };
106
107 static int
msdosfs_deget_dotdot(struct mount * mp,void * arg,int lkflags,struct vnode ** rvp)108 msdosfs_deget_dotdot(struct mount *mp, void *arg, int lkflags,
109 struct vnode **rvp)
110 {
111 struct deget_dotdot *dd_arg;
112 struct denode *rdp;
113 struct msdosfsmount *pmp;
114 int error;
115
116 pmp = VFSTOMSDOSFS(mp);
117 dd_arg = arg;
118 error = deget(pmp, dd_arg->cluster, dd_arg->blkoff,
119 LK_EXCLUSIVE, &rdp);
120 if (error == 0)
121 *rvp = DETOV(rdp);
122 return (error);
123 }
124
125 /*
126 * When we search a directory the blocks containing directory entries are
127 * read and examined. The directory entries contain information that would
128 * normally be in the inode of a unix filesystem. This means that some of
129 * a directory's contents may also be in memory resident denodes (sort of
130 * an inode). This can cause problems if we are searching while some other
131 * process is modifying a directory. To prevent one process from accessing
132 * incompletely modified directory information we depend upon being the
133 * sole owner of a directory block. bread/brelse provide this service.
134 * This being the case, when a process modifies a directory it must first
135 * acquire the disk block that contains the directory entry to be modified.
136 * Then update the disk block and the denode, and then write the disk block
137 * out to disk. This way disk blocks containing directory entries and in
138 * memory denode's will be in synch.
139 */
140 int
msdosfs_lookup_ino(struct vnode * vdp,struct vnode ** vpp,struct componentname * cnp,daddr_t * scnp,u_long * blkoffp)141 msdosfs_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname
142 *cnp, daddr_t *scnp, u_long *blkoffp)
143 {
144 struct mbnambuf nb;
145 daddr_t bn;
146 int error;
147 int slotcount;
148 int slotoffset = 0;
149 int frcn;
150 u_long cluster;
151 u_long blkoff;
152 int diroff;
153 int blsize;
154 int isadir; /* ~0 if found direntry is a directory */
155 u_long scn; /* starting cluster number */
156 // Haiku port: type changed to avoid compiler warning
157 struct vnode *pdp;
158 struct denode *dp;
159 struct denode *tdp;
160 struct msdosfsmount *pmp;
161 struct buf *bp = NULL;
162 struct direntry *dep = NULL;
163 struct deget_dotdot dd_arg;
164 u_char dosfilename[12];
165 int flags = cnp->cn_flags;
166 int nameiop = cnp->cn_nameiop;
167 int unlen;
168 uint64_t inode1;
169
170 int wincnt = 1;
171 int chksum = -1, chksum_ok;
172 int olddos = 1;
173
174 #ifdef MSDOSFS_DEBUG
175 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr);
176 #endif
177 dp = VTODE(vdp);
178 pmp = dp->de_pmp;
179 #ifdef MSDOSFS_DEBUG
180 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n",
181 vdp, dp, dp->de_Attributes);
182 #endif
183
184 restart:
185 if (vpp != NULL)
186 *vpp = NULL;
187 /*
188 * If they are going after the . or .. entry in the root directory,
189 * they won't find it. DOS filesystems don't have them in the root
190 * directory. So, we fake it. deget() is in on this scam too.
191 */
192 if ((vdp->v_vflag & VV_ROOT) && cnp->cn_nameptr[0] == '.' &&
193 (cnp->cn_namelen == 1 ||
194 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
195 isadir = ATTR_DIRECTORY;
196 scn = MSDOSFSROOT;
197 #ifdef MSDOSFS_DEBUG
198 printf("msdosfs_lookup(): looking for . or .. in root directory\n");
199 #endif
200 cluster = MSDOSFSROOT;
201 blkoff = MSDOSFSROOT_OFS;
202 goto foundroot;
203 }
204
205 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename,
206 cnp->cn_namelen, 0, pmp)) {
207 case 0:
208 return (EINVAL);
209 case 1:
210 break;
211 case 2:
212 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
213 cnp->cn_namelen, pmp) + 1;
214 break;
215 case 3:
216 olddos = 0;
217 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
218 cnp->cn_namelen, pmp) + 1;
219 break;
220 }
221 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) {
222 wincnt = 1;
223 olddos = 1;
224 }
225 unlen = winLenFixup((u_char *)cnp->cn_nameptr, cnp->cn_namelen);
226 // Haiku port: cast added to avoid compiler warning
227
228 /*
229 * Suppress search for slots unless creating
230 * file and at end of pathname, in which case
231 * we watch for a place to put the new file in
232 * case it doesn't already exist.
233 */
234 slotcount = wincnt;
235 if ((nameiop == CREATE || nameiop == RENAME) &&
236 (flags & ISLASTCN))
237 slotcount = 0;
238
239 #ifdef MSDOSFS_DEBUG
240 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n",
241 dosfilename, cnp->cn_namelen);
242 #endif
243 /*
244 * Search the directory pointed at by vdp for the name pointed at
245 * by cnp->cn_nameptr.
246 */
247 tdp = NULL;
248 mbnambuf_init(&nb);
249 /*
250 * The outer loop ranges over the clusters that make up the
251 * directory. Note that the root directory is different from all
252 * other directories. It has a fixed number of blocks that are not
253 * part of the pool of allocatable clusters. So, we treat it a
254 * little differently. The root directory starts at "cluster" 0.
255 */
256 diroff = 0;
257 for (frcn = 0;; frcn++) {
258 error = pcbmap(dp, frcn, &bn, &cluster, &blsize);
259 if (error) {
260 if (error == E2BIG)
261 break;
262 return (error);
263 }
264 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
265 if (error) {
266 return (error);
267 }
268 for (blkoff = 0; blkoff < (u_long)blsize;
269 blkoff += sizeof(struct direntry),
270 diroff += sizeof(struct direntry)) {
271 // Haiku port: cast added to avoid compiler warning
272 dep = (struct direntry *)(bp->b_data + blkoff);
273 /*
274 * If the slot is empty and we are still looking
275 * for an empty then remember this one. If the
276 * slot is not empty then check to see if it
277 * matches what we are looking for. If the slot
278 * has never been filled with anything, then the
279 * remainder of the directory has never been used,
280 * so there is no point in searching it.
281 */
282 if (dep->deName[0] == SLOT_EMPTY ||
283 dep->deName[0] == SLOT_DELETED) {
284 /*
285 * Drop memory of previous long matches
286 */
287 chksum = -1;
288 mbnambuf_init(&nb);
289
290 if (slotcount < wincnt) {
291 slotcount++;
292 slotoffset = diroff;
293 }
294 if (dep->deName[0] == SLOT_EMPTY) {
295 brelse(bp);
296 goto notfound;
297 }
298 } else {
299 /*
300 * If there wasn't enough space for our winentries,
301 * forget about the empty space
302 */
303 if (slotcount < wincnt)
304 slotcount = 0;
305
306 /*
307 * Check for Win95 long filename entry
308 */
309 if (dep->deAttributes == ATTR_WIN95) {
310 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
311 continue;
312
313 chksum = win2unixfn(&nb,
314 (struct winentry *)dep, chksum,
315 pmp);
316 continue;
317 }
318
319 chksum = winChkName(&nb,
320 (const u_char *)cnp->cn_nameptr, unlen,
321 chksum, pmp);
322 if (chksum == -2) {
323 chksum = -1;
324 continue;
325 }
326
327 /*
328 * Ignore volume labels (anywhere, not just
329 * the root directory).
330 */
331 if (dep->deAttributes & ATTR_VOLUME) {
332 chksum = -1;
333 continue;
334 }
335
336 /*
337 * Check for a checksum or name match
338 */
339 chksum_ok = (chksum == winChksum(dep->deName));
340 if (!chksum_ok
341 && (!olddos || bcmp(dosfilename, dep->deName, 11))) {
342 chksum = -1;
343 continue;
344 }
345 #ifdef MSDOSFS_DEBUG
346 printf("msdosfs_lookup(): match blkoff %lu, diroff %d\n",
347 blkoff, diroff);
348 #endif
349 /*
350 * Remember where this directory
351 * entry came from for whoever did
352 * this lookup.
353 */
354 dp->de_fndoffset = diroff;
355 if (chksum_ok && nameiop == RENAME) {
356 /*
357 * Target had correct long name
358 * directory entries, reuse them
359 * as needed.
360 */
361 dp->de_fndcnt = wincnt - 1;
362 } else {
363 /*
364 * Long name directory entries
365 * not present or corrupt, can only
366 * reuse dos directory entry.
367 */
368 dp->de_fndcnt = 0;
369 }
370
371 goto found;
372 }
373 } /* for (blkoff = 0; .... */
374 /*
375 * Release the buffer holding the directory cluster just
376 * searched.
377 */
378 brelse(bp);
379 } /* for (frcn = 0; ; frcn++) */
380
381 notfound:
382 /*
383 * We hold no disk buffers at this point.
384 */
385
386 /*
387 * Fixup the slot description to point to the place where
388 * we might put the new DOS direntry (putting the Win95
389 * long name entries before that)
390 */
391 if (!slotcount) {
392 slotcount = 1;
393 slotoffset = diroff;
394 }
395 if (wincnt > slotcount)
396 slotoffset += sizeof(struct direntry) * (wincnt - slotcount);
397
398 /*
399 * If we get here we didn't find the entry we were looking for. But
400 * that's ok if we are creating or renaming and are at the end of
401 * the pathname and the directory hasn't been removed.
402 */
403 #ifdef MSDOSFS_DEBUG
404 printf("msdosfs_lookup(): op %d, refcnt %ld\n",
405 nameiop, dp->de_refcnt);
406 printf(" slotcount %d, slotoffset %d\n",
407 slotcount, slotoffset);
408 #endif
409 if ((nameiop == CREATE || nameiop == RENAME) &&
410 (flags & ISLASTCN) && dp->de_refcnt != 0) {
411 /*
412 * Access for write is interpreted as allowing
413 * creation of files in the directory.
414 */
415 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, curthread);
416 if (error)
417 return (error);
418 /*
419 * Return an indication of where the new directory
420 * entry should be put.
421 */
422 dp->de_fndoffset = slotoffset;
423 dp->de_fndcnt = wincnt - 1;
424
425 /*
426 * We return with the directory locked, so that
427 * the parameters we set up above will still be
428 * valid if we actually decide to do a direnter().
429 * We return ni_vp == NULL to indicate that the entry
430 * does not currently exist; we leave a pointer to
431 * the (locked) directory inode in ndp->ni_dvp.
432 *
433 * NB - if the directory is unlocked, then this
434 * information cannot be used.
435 */
436 return (EJUSTRETURN);
437 }
438 #if 0
439 /*
440 * Insert name into cache (as non-existent) if appropriate.
441 *
442 * XXX Negative caching is broken for msdosfs because the name
443 * cache doesn't understand peculiarities such as case insensitivity
444 * and 8.3 filenames. Hence, it may not invalidate all negative
445 * entries if a file with this name is later created.
446 */
447 if ((cnp->cn_flags & MAKEENTRY) != 0)
448 cache_enter(vdp, *vpp, cnp);
449 #endif
450 return (ENOENT);
451
452 found:
453 /*
454 * NOTE: We still have the buffer with matched directory entry at
455 * this point.
456 */
457 isadir = dep->deAttributes & ATTR_DIRECTORY;
458 scn = getushort(dep->deStartCluster);
459 if (FAT32(pmp)) {
460 scn |= getushort(dep->deHighClust) << 16;
461 if (scn == pmp->pm_rootdirblk) {
462 /*
463 * There should actually be 0 here.
464 * Just ignore the error.
465 */
466 scn = MSDOSFSROOT;
467 }
468 }
469
470 if (isadir) {
471 cluster = scn;
472 if (cluster == MSDOSFSROOT)
473 blkoff = MSDOSFSROOT_OFS;
474 else
475 blkoff = 0;
476 } else if (cluster == MSDOSFSROOT)
477 blkoff = diroff;
478
479 /*
480 * Now release buf to allow deget to read the entry again.
481 * Reserving it here and giving it to deget could result
482 * in a deadlock.
483 */
484 brelse(bp);
485 bp = NULL;
486
487 foundroot:
488 /*
489 * If we entered at foundroot, then we are looking for the . or ..
490 * entry of the filesystems root directory. isadir and scn were
491 * setup before jumping here. And, bp is already null.
492 */
493 if (FAT32(pmp) && scn == MSDOSFSROOT)
494 scn = pmp->pm_rootdirblk;
495
496 if (scnp != NULL) {
497 *scnp = cluster;
498 *blkoffp = blkoff;
499 return (0);
500 }
501
502 /*
503 * If deleting, and at end of pathname, return
504 * parameters which can be used to remove file.
505 */
506 if (nameiop == DELETE && (flags & ISLASTCN)) {
507 /*
508 * Don't allow deleting the root.
509 */
510 if (blkoff == MSDOSFSROOT_OFS)
511 return (EBUSY);
512
513 /*
514 * Write access to directory required to delete files.
515 */
516 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, curthread);
517 if (error)
518 return (error);
519
520 /*
521 * Return pointer to current entry in dp->i_offset.
522 * Save directory inode pointer in ndp->ni_dvp for dirremove().
523 */
524 if (dp->de_StartCluster == scn && isadir) { /* "." */
525 VREF(vdp);
526 *vpp = vdp;
527 return (0);
528 }
529 error = deget(pmp, cluster, blkoff, LK_EXCLUSIVE, &tdp);
530 if (error)
531 return (error);
532 return (msdosfs_lookup_checker(pmp, vdp, tdp, vpp));
533 }
534
535 /*
536 * If rewriting (RENAME), return the inode and the
537 * information required to rewrite the present directory
538 * Must get inode of directory entry to verify it's a
539 * regular file, or empty directory.
540 */
541 if (nameiop == RENAME && (flags & ISLASTCN)) {
542 if (blkoff == MSDOSFSROOT_OFS)
543 return (EBUSY);
544
545 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, curthread);
546 if (error)
547 return (error);
548
549 /*
550 * Careful about locking second inode.
551 * This can only occur if the target is ".".
552 */
553 if (dp->de_StartCluster == scn && isadir)
554 return (EISDIR);
555
556 if ((error = deget(pmp, cluster, blkoff, LK_EXCLUSIVE,
557 &tdp)) != 0)
558 return (error);
559 if ((error = msdosfs_lookup_checker(pmp, vdp, tdp, vpp))
560 != 0)
561 return (error);
562 return (0);
563 }
564
565 /*
566 * Step through the translation in the name. We do not `vput' the
567 * directory because we may need it again if a symbolic link
568 * is relative to the current directory. Instead we save it
569 * unlocked as "pdp". We must get the target inode before unlocking
570 * the directory to insure that the inode will not be removed
571 * before we get it. We prevent deadlock by always fetching
572 * inodes from the root, moving down the directory tree. Thus
573 * when following backward pointers ".." we must unlock the
574 * parent directory before getting the requested directory.
575 */
576 pdp = vdp;
577 if (flags & ISDOTDOT) {
578 dd_arg.cluster = cluster;
579 dd_arg.blkoff = blkoff;
580 error = vn_vget_ino_gen(vdp, msdosfs_deget_dotdot,
581 &dd_arg, cnp->cn_lkflags, vpp);
582 if (error != 0) {
583 *vpp = NULL;
584 return (error);
585 }
586 /*
587 * Recheck that ".." still points to the inode we
588 * looked up before pdp lock was dropped.
589 */
590 error = msdosfs_lookup_ino(pdp, NULL, cnp, (daddr_t *)&scn, &blkoff);
591 // Haiku port: cast added to avoid compiler warning
592 if (error) {
593 vput(*vpp);
594 *vpp = NULL;
595 return (error);
596 }
597 if (FAT32(pmp) && scn == MSDOSFSROOT)
598 scn = pmp->pm_rootdirblk;
599 inode1 = DETOI(pmp, scn, blkoff);
600 if (VTODE(*vpp)->de_inode != inode1) {
601 vput(*vpp);
602 goto restart;
603 }
604 error = msdosfs_lookup_checker(pmp, vdp, VTODE(*vpp), vpp);
605 if (error != 0)
606 return (error);
607 } else if (dp->de_StartCluster == scn && isadir) {
608 if (cnp->cn_namelen != 1 || cnp->cn_nameptr[0] != '.') {
609 /* fs is corrupted, non-dot lookup returned dvp */
610 msdosfs_integrity_error(pmp);
611 return (EBADF);
612 }
613 VREF(vdp); /* we want ourself, ie "." */
614 *vpp = vdp;
615 } else {
616 if ((error = deget(pmp, cluster, blkoff, LK_EXCLUSIVE,
617 &tdp)) != 0)
618 return (error);
619 if ((error = msdosfs_lookup_checker(pmp, vdp, tdp, vpp)) != 0)
620 return (error);
621 }
622
623 /*
624 * Insert name into cache if appropriate.
625 */
626 if (cnp->cn_flags & MAKEENTRY)
627 cache_enter(vdp, *vpp, cnp);
628 return (0);
629 }
630
631 /*
632 * dep - directory entry to copy into the directory
633 * ddep - directory to add to
634 * depp - return the address of the denode for the created directory entry
635 * if depp != 0
636 * cnp - componentname needed for Win95 long filenames
637 */
638 int
createde(struct denode * dep,struct denode * ddep,struct denode ** depp,struct componentname * cnp)639 createde(struct denode *dep, struct denode *ddep, struct denode **depp,
640 struct componentname *cnp)
641 {
642 int error;
643 u_long dirclust, diroffset;
644 struct direntry *ndep;
645 struct msdosfsmount *pmp = ddep->de_pmp;
646 struct buf *bp;
647 daddr_t bn;
648 int blsize;
649
650 #ifdef MSDOSFS_DEBUG
651 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
652 dep, ddep, depp, cnp);
653 #endif
654
655 /*
656 * If no space left in the directory then allocate another cluster
657 * and chain it onto the end of the file. There is one exception
658 * to this. That is, if the root directory has no more space it
659 * can NOT be expanded. extendfile() checks for and fails attempts
660 * to extend the root directory. We just return an error in that
661 * case.
662 */
663 if (ddep->de_fndoffset >= ddep->de_FileSize) {
664 diroffset = ddep->de_fndoffset + sizeof(struct direntry)
665 - ddep->de_FileSize;
666 dirclust = de_clcount(pmp, diroffset);
667 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR);
668 if (error) {
669 (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED);
670 return error;
671 }
672
673 /*
674 * Update the size of the directory
675 */
676 ddep->de_FileSize += de_cn2off(pmp, dirclust);
677 }
678
679 /*
680 * We just read in the cluster with space. Copy the new directory
681 * entry in. Then write it to disk. NOTE: DOS directories
682 * do not get smaller as clusters are emptied.
683 */
684 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset),
685 &bn, &dirclust, &blsize);
686 if (error)
687 return error;
688 diroffset = ddep->de_fndoffset;
689 if (dirclust != MSDOSFSROOT)
690 diroffset &= pmp->pm_crbomask;
691 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) {
692 brelse(bp);
693 return error;
694 }
695 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
696 rootde_alloced(ddep);
697
698 DE_EXTERNALIZE(ndep, dep);
699
700 /*
701 * Now write the Win95 long name
702 */
703 if (ddep->de_fndcnt > 0) {
704 uint8_t chksum = winChksum(ndep->deName);
705 const u_char *un = (const u_char *)cnp->cn_nameptr;
706 int unlen = cnp->cn_namelen;
707 int cnt = 1;
708
709 while (--ddep->de_fndcnt >= 0) {
710 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) {
711 if (DOINGASYNC(DETOV(ddep)))
712 bdwrite(bp);
713 else if ((error = bwrite(bp)) != 0)
714 return error;
715
716 ddep->de_fndoffset -= sizeof(struct direntry);
717 error = pcbmap(ddep,
718 de_cluster(pmp,
719 ddep->de_fndoffset),
720 &bn, 0, &blsize);
721 if (error)
722 return error;
723
724 error = bread(pmp->pm_devvp, bn, blsize,
725 NOCRED, &bp);
726 if (error) {
727 return error;
728 }
729 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
730 } else {
731 ndep--;
732 ddep->de_fndoffset -= sizeof(struct direntry);
733 }
734 rootde_alloced(ddep);
735 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
736 cnt++, chksum, pmp))
737 break;
738 }
739 }
740
741 if (DOINGASYNC(DETOV(ddep)))
742 bdwrite(bp);
743 else if ((error = bwrite(bp)) != 0)
744 return error;
745
746 /*
747 * If they want us to return with the denode gotten.
748 */
749 if (depp) {
750 if (dep->de_Attributes & ATTR_DIRECTORY) {
751 dirclust = dep->de_StartCluster;
752 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)
753 dirclust = MSDOSFSROOT;
754 if (dirclust == MSDOSFSROOT)
755 diroffset = MSDOSFSROOT_OFS;
756 else
757 diroffset = 0;
758 }
759 return (deget(pmp, dirclust, diroffset, LK_EXCLUSIVE, depp));
760 }
761
762 return 0;
763 }
764
765 /*
766 * Be sure a directory is empty except for "." and "..". Return 1 if empty,
767 * return 0 if not empty or error.
768 */
769 int
dosdirempty(struct denode * dep)770 dosdirempty(struct denode *dep)
771 {
772 int blsize;
773 int error;
774 u_long cn;
775 daddr_t bn;
776 struct buf *bp;
777 struct msdosfsmount *pmp = dep->de_pmp;
778 struct direntry *dentp;
779
780 /*
781 * Since the filesize field in directory entries for a directory is
782 * zero, we just have to feel our way through the directory until
783 * we hit end of file.
784 */
785 for (cn = 0;; cn++) {
786 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
787 if (error == E2BIG)
788 return (1); /* it's empty */
789 return (0);
790 }
791 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
792 if (error) {
793 return (0);
794 }
795 for (dentp = (struct direntry *)bp->b_data;
796 (char *)dentp < bp->b_data + blsize;
797 dentp++) {
798 if (dentp->deName[0] != SLOT_DELETED &&
799 (dentp->deAttributes & ATTR_VOLUME) == 0) {
800 /*
801 * In dos directories an entry whose name
802 * starts with SLOT_EMPTY (0) starts the
803 * beginning of the unused part of the
804 * directory, so we can just return that it
805 * is empty.
806 */
807 if (dentp->deName[0] == SLOT_EMPTY) {
808 brelse(bp);
809 return (1);
810 }
811 /*
812 * Any names other than "." and ".." in a
813 * directory mean it is not empty.
814 */
815 if (bcmp(dentp->deName, ". ", 11) &&
816 bcmp(dentp->deName, ".. ", 11)) {
817 brelse(bp);
818 #ifdef MSDOSFS_DEBUG
819 printf("dosdirempty(): entry found %02x, %02x\n",
820 dentp->deName[0], dentp->deName[1]);
821 #endif
822 return (0); /* not empty */
823 }
824 }
825 }
826 brelse(bp);
827 }
828 /* NOTREACHED */
829 }
830
831 /*
832 * Check to see if the directory described by target is in some
833 * subdirectory of source. This prevents something like the following from
834 * succeeding and leaving a bunch or files and directories orphaned. mv
835 * /a/b/c /a/b/c/d/e/f Where c and f are directories.
836 *
837 * source - the inode for /a/b/c
838 * target - the inode for /a/b/c/d/e/f
839 *
840 * Returns 0 if target is NOT a subdirectory of source.
841 * Otherwise returns a non-zero error number.
842 */
843 int
doscheckpath(struct denode * source,struct denode * target,daddr_t * wait_scn)844 doscheckpath(struct denode *source, struct denode *target, daddr_t *wait_scn)
845 {
846 u_long scn;
847 // Haiku port: type changed to avoid compiler warning
848 struct msdosfsmount *pmp;
849 struct direntry *ep;
850 struct denode *dep;
851 struct buf *bp = NULL;
852 int error = 0;
853
854 *wait_scn = 0;
855
856 pmp = target->de_pmp;
857 lockmgr_assert(&pmp->pm_checkpath_lock, KA_XLOCKED);
858 KASSERT(pmp == source->de_pmp,
859 ("doscheckpath: source and target on different filesystems"));
860
861 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
862 (source->de_Attributes & ATTR_DIRECTORY) == 0)
863 return (ENOTDIR);
864
865 if (target->de_StartCluster == source->de_StartCluster)
866 return (EEXIST);
867
868 if (target->de_StartCluster == MSDOSFSROOT ||
869 (FAT32(pmp) && target->de_StartCluster == pmp->pm_rootdirblk))
870 return (0);
871
872 dep = target;
873 vget(DETOV(dep), LK_EXCLUSIVE);
874 for (;;) {
875 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
876 error = ENOTDIR;
877 break;
878 }
879 scn = dep->de_StartCluster;
880 error = bread(pmp->pm_devvp, cntobn(pmp, scn),
881 pmp->pm_bpcluster, NOCRED, &bp);
882 if (error != 0)
883 break;
884
885 ep = (struct direntry *)bp->b_data + 1;
886 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
887 bcmp(ep->deName, ".. ", 11) != 0) {
888 error = ENOTDIR;
889 brelse(bp);
890 break;
891 }
892
893 scn = getushort(ep->deStartCluster);
894 if (FAT32(pmp))
895 scn |= getushort(ep->deHighClust) << 16;
896 brelse(bp);
897
898 if (scn == source->de_StartCluster) {
899 error = EINVAL;
900 break;
901 }
902 if (scn == MSDOSFSROOT)
903 break;
904 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) {
905 /*
906 * scn should be 0 in this case,
907 * but we silently ignore the error.
908 */
909 break;
910 }
911
912 vput(DETOV(dep));
913 dep = NULL;
914 /* NOTE: deget() clears dep on error */
915 error = deget(pmp, scn, 0, LK_EXCLUSIVE | LK_NOWAIT, &dep);
916 if (error != 0) {
917 *wait_scn = scn;
918 break;
919 }
920 }
921 #ifdef MSDOSFS_DEBUG
922 if (error == ENOTDIR)
923 printf("doscheckpath(): .. not a directory?\n");
924 #endif
925 if (dep != NULL)
926 vput(DETOV(dep));
927 return (error);
928 }
929
930 /*
931 * Read in the disk block containing the directory entry (dirclu, dirofs)
932 * and return the address of the buf header, and the address of the
933 * directory entry within the block.
934 */
935 int
readep(struct msdosfsmount * pmp,u_long dirclust,u_long diroffset,struct buf ** bpp,struct direntry ** epp)936 readep(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
937 struct buf **bpp, struct direntry **epp)
938 {
939 int error;
940 daddr_t bn;
941 int blsize;
942
943 blsize = pmp->pm_bpcluster;
944 if (dirclust == MSDOSFSROOT
945 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize)
946 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask;
947 bn = detobn(pmp, dirclust, diroffset);
948 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) {
949 brelse(*bpp);
950 *bpp = NULL;
951 return (error);
952 }
953 if (epp)
954 *epp = bptoep(pmp, *bpp, diroffset);
955 return (0);
956 }
957
958 /*
959 * Read in the disk block containing the directory entry dep came from and
960 * return the address of the buf header, and the address of the directory
961 * entry within the block.
962 */
963 int
readde(struct denode * dep,struct buf ** bpp,struct direntry ** epp)964 readde(struct denode *dep, struct buf **bpp, struct direntry **epp)
965 {
966
967 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
968 bpp, epp));
969 }
970
971 /*
972 * Remove a directory entry. At this point the file represented by the
973 * directory entry to be removed is still full length until no one has it
974 * open. When the file no longer being used msdosfs_inactive() is called
975 * and will truncate the file to 0 length. When the vnode containing the
976 * denode is needed for some other purpose by VFS it will call
977 * msdosfs_reclaim() which will remove the denode from the denode cache.
978 *
979 * pdep directory where the entry is removed
980 * dep file to be removed
981 */
982 int
removede(struct denode * pdep,struct denode * dep)983 removede(struct denode *pdep, struct denode *dep)
984 {
985 int error;
986 struct direntry *ep;
987 struct buf *bp;
988 daddr_t bn;
989 int blsize;
990 struct msdosfsmount *pmp = pdep->de_pmp;
991 u_long offset = pdep->de_fndoffset;
992
993 #ifdef MSDOSFS_DEBUG
994 printf("removede(): filename %s, dep %p, offset %08lx\n",
995 dep->de_Name, dep, offset);
996 #endif
997
998 dep->de_refcnt--;
999 offset += sizeof(struct direntry);
1000 do {
1001 offset -= sizeof(struct direntry);
1002 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize);
1003 if (error)
1004 return error;
1005 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
1006 if (error) {
1007 return error;
1008 }
1009 ep = bptoep(pmp, bp, offset);
1010 /*
1011 * Check whether, if we came here the second time, i.e.
1012 * when underflowing into the previous block, the last
1013 * entry in this block is a longfilename entry, too.
1014 */
1015 if (ep->deAttributes != ATTR_WIN95
1016 && offset != pdep->de_fndoffset) {
1017 brelse(bp);
1018 break;
1019 }
1020 offset += sizeof(struct direntry);
1021 while (1) {
1022 /*
1023 * We are a bit aggressive here in that we delete any Win95
1024 * entries preceding this entry, not just the ones we "own".
1025 * Since these presumably aren't valid anyway,
1026 * there should be no harm.
1027 */
1028 offset -= sizeof(struct direntry);
1029 ep--->deName[0] = SLOT_DELETED;
1030 rootde_freed(pdep);
1031 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95)
1032 || !(offset & pmp->pm_crbomask)
1033 || ep->deAttributes != ATTR_WIN95)
1034 break;
1035 }
1036 if (DOINGASYNC(DETOV(pdep)))
1037 bdwrite(bp);
1038 else if ((error = bwrite(bp)) != 0)
1039 return error;
1040 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95)
1041 && !(offset & pmp->pm_crbomask)
1042 && offset);
1043 return 0;
1044 }
1045
1046 /*
1047 * Create a unique DOS name in dvp
1048 */
1049 int
uniqdosname(struct denode * dep,struct componentname * cnp,u_char * cp)1050 uniqdosname(struct denode *dep, struct componentname *cnp, u_char *cp)
1051 {
1052 struct msdosfsmount *pmp = dep->de_pmp;
1053 struct direntry *dentp;
1054 int gen;
1055 int blsize;
1056 u_long cn;
1057 daddr_t bn;
1058 struct buf *bp;
1059 int error;
1060
1061 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
1062 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
1063 cnp->cn_namelen, 0, pmp) ? 0 : EINVAL);
1064
1065 for (gen = 1;; gen++) {
1066 /*
1067 * Generate DOS name with generation number
1068 */
1069 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
1070 cnp->cn_namelen, gen, pmp))
1071 return gen == 1 ? EINVAL : EEXIST;
1072
1073 /*
1074 * Now look for a dir entry with this exact name
1075 */
1076 for (cn = error = 0; !error; cn++) {
1077 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
1078 if (error == E2BIG) /* EOF reached and not found */
1079 return 0;
1080 return error;
1081 }
1082 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
1083 if (error) {
1084 return error;
1085 }
1086 for (dentp = (struct direntry *)bp->b_data;
1087 (char *)dentp < bp->b_data + blsize;
1088 dentp++) {
1089 if (dentp->deName[0] == SLOT_EMPTY) {
1090 /*
1091 * Last used entry and not found
1092 */
1093 brelse(bp);
1094 return 0;
1095 }
1096 /*
1097 * Ignore volume labels and Win95 entries
1098 */
1099 if (dentp->deAttributes & ATTR_VOLUME)
1100 continue;
1101 if (!bcmp(dentp->deName, cp, 11)) {
1102 error = EEXIST;
1103 break;
1104 }
1105 }
1106 brelse(bp);
1107 }
1108 }
1109 }
1110