63
64/*
65 * When we search a directory the blocks containing directory entries are
66 * read and examined. The directory entries contain information that would
67 * normally be in the inode of a unix filesystem. This means that some of
68 * a directory's contents may also be in memory resident denodes (sort of
69 * an inode). This can cause problems if we are searching while some other
70 * process is modifying a directory. To prevent one process from accessing
71 * incompletely modified directory information we depend upon being the
72 * sole owner of a directory block. bread/brelse provide this service.
73 * This being the case, when a process modifies a directory it must first
74 * acquire the disk block that contains the directory entry to be modified.
75 * Then update the disk block and the denode, and then write the disk block
76 * out to disk. This way disk blocks containing directory entries and in
77 * memory denode's will be in synch.
78 */
79int
80msdosfs_lookup(ap)
81 struct vop_cachedlookup_args /* {
82 struct vnode *a_dvp;
83 struct vnode **a_vpp;
84 struct componentname *a_cnp;
85 } */ *ap;
86{
87 struct vnode *vdp = ap->a_dvp;
88 struct vnode **vpp = ap->a_vpp;
89 struct componentname *cnp = ap->a_cnp;
90 daddr_t bn;
91 int error;
92 int slotcount;
93 int slotoffset = 0;
94 int frcn;
95 u_long cluster;
96 int blkoff;
97 int diroff;
98 int blsize;
99 int isadir; /* ~0 if found direntry is a directory */
100 u_long scn; /* starting cluster number */
101 struct vnode *pdp;
102 struct denode *dp;
103 struct denode *tdp;
104 struct msdosfsmount *pmp;
105 struct buf *bp = 0;
106 struct direntry *dep = NULL;
107 u_char dosfilename[12];
108 int flags = cnp->cn_flags;
109 int nameiop = cnp->cn_nameiop;
110 struct thread *td = cnp->cn_thread;
111 int unlen;
112
113 int wincnt = 1;
114 int chksum = -1, chksum_ok;
115 int olddos = 1;
116
117#ifdef MSDOSFS_DEBUG
118 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr);
119#endif
120 dp = VTODE(vdp);
121 pmp = dp->de_pmp;
122 *vpp = NULL;
123#ifdef MSDOSFS_DEBUG
124 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n",
125 vdp, dp, dp->de_Attributes);
126#endif
127
128 /*
129 * If they are going after the . or .. entry in the root directory,
130 * they won't find it. DOS filesystems don't have them in the root
131 * directory. So, we fake it. deget() is in on this scam too.
132 */
133 if ((vdp->v_vflag & VV_ROOT) && cnp->cn_nameptr[0] == '.' &&
134 (cnp->cn_namelen == 1 ||
135 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
136 isadir = ATTR_DIRECTORY;
137 scn = MSDOSFSROOT;
138#ifdef MSDOSFS_DEBUG
139 printf("msdosfs_lookup(): looking for . or .. in root directory\n");
140#endif
141 cluster = MSDOSFSROOT;
142 blkoff = MSDOSFSROOT_OFS;
143 goto foundroot;
144 }
145
146 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename,
147 cnp->cn_namelen, 0, pmp)) {
148 case 0:
149 return (EINVAL);
150 case 1:
151 break;
152 case 2:
153 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
154 cnp->cn_namelen, pmp) + 1;
155 break;
156 case 3:
157 olddos = 0;
158 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
159 cnp->cn_namelen, pmp) + 1;
160 break;
161 }
162 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) {
163 wincnt = 1;
164 olddos = 1;
165 }
166 unlen = winLenFixup(cnp->cn_nameptr, cnp->cn_namelen);
167
168 /*
169 * Suppress search for slots unless creating
170 * file and at end of pathname, in which case
171 * we watch for a place to put the new file in
172 * case it doesn't already exist.
173 */
174 slotcount = wincnt;
175 if ((nameiop == CREATE || nameiop == RENAME) &&
176 (flags & ISLASTCN))
177 slotcount = 0;
178
179#ifdef MSDOSFS_DEBUG
180 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n",
181 dosfilename, cnp->cn_namelen);
182#endif
183 /*
184 * Search the directory pointed at by vdp for the name pointed at
185 * by cnp->cn_nameptr.
186 */
187 tdp = NULL;
188 mbnambuf_init();
189 /*
190 * The outer loop ranges over the clusters that make up the
191 * directory. Note that the root directory is different from all
192 * other directories. It has a fixed number of blocks that are not
193 * part of the pool of allocatable clusters. So, we treat it a
194 * little differently. The root directory starts at "cluster" 0.
195 */
196 diroff = 0;
197 for (frcn = 0;; frcn++) {
198 error = pcbmap(dp, frcn, &bn, &cluster, &blsize);
199 if (error) {
200 if (error == E2BIG)
201 break;
202 return (error);
203 }
204 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
205 if (error) {
206 brelse(bp);
207 return (error);
208 }
209 for (blkoff = 0; blkoff < blsize;
210 blkoff += sizeof(struct direntry),
211 diroff += sizeof(struct direntry)) {
212 dep = (struct direntry *)(bp->b_data + blkoff);
213 /*
214 * If the slot is empty and we are still looking
215 * for an empty then remember this one. If the
216 * slot is not empty then check to see if it
217 * matches what we are looking for. If the slot
218 * has never been filled with anything, then the
219 * remainder of the directory has never been used,
220 * so there is no point in searching it.
221 */
222 if (dep->deName[0] == SLOT_EMPTY ||
223 dep->deName[0] == SLOT_DELETED) {
224 /*
225 * Drop memory of previous long matches
226 */
227 chksum = -1;
228 mbnambuf_init();
229
230 if (slotcount < wincnt) {
231 slotcount++;
232 slotoffset = diroff;
233 }
234 if (dep->deName[0] == SLOT_EMPTY) {
235 brelse(bp);
236 goto notfound;
237 }
238 } else {
239 /*
240 * If there wasn't enough space for our winentries,
241 * forget about the empty space
242 */
243 if (slotcount < wincnt)
244 slotcount = 0;
245
246 /*
247 * Check for Win95 long filename entry
248 */
249 if (dep->deAttributes == ATTR_WIN95) {
250 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
251 continue;
252
253 chksum = win2unixfn((struct winentry *)dep,
254 chksum,
255 pmp);
256 continue;
257 }
258
259 chksum = winChkName((const u_char *)cnp->cn_nameptr,
260 unlen,
261 chksum,
262 pmp);
263 if (chksum == -2) {
264 chksum = -1;
265 continue;
266 }
267
268 /*
269 * Ignore volume labels (anywhere, not just
270 * the root directory).
271 */
272 if (dep->deAttributes & ATTR_VOLUME) {
273 chksum = -1;
274 continue;
275 }
276
277 /*
278 * Check for a checksum or name match
279 */
280 chksum_ok = (chksum == winChksum(dep));
281 if (!chksum_ok
282 && (!olddos || bcmp(dosfilename, dep->deName, 11))) {
283 chksum = -1;
284 continue;
285 }
286#ifdef MSDOSFS_DEBUG
287 printf("msdosfs_lookup(): match blkoff %d, diroff %d\n",
288 blkoff, diroff);
289#endif
290 /*
291 * Remember where this directory
292 * entry came from for whoever did
293 * this lookup.
294 */
295 dp->de_fndoffset = diroff;
296 if (chksum_ok && nameiop == RENAME) {
297 /*
298 * Target had correct long name
299 * directory entries, reuse them
300 * as needed.
301 */
302 dp->de_fndcnt = wincnt - 1;
303 } else {
304 /*
305 * Long name directory entries
306 * not present or corrupt, can only
307 * reuse dos directory entry.
308 */
309 dp->de_fndcnt = 0;
310 }
311
312 goto found;
313 }
314 } /* for (blkoff = 0; .... */
315 /*
316 * Release the buffer holding the directory cluster just
317 * searched.
318 */
319 brelse(bp);
320 } /* for (frcn = 0; ; frcn++) */
321
322notfound:
323 /*
324 * We hold no disk buffers at this point.
325 */
326
327 /*
328 * Fixup the slot description to point to the place where
329 * we might put the new DOS direntry (putting the Win95
330 * long name entries before that)
331 */
332 if (!slotcount) {
333 slotcount = 1;
334 slotoffset = diroff;
335 }
336 if (wincnt > slotcount)
337 slotoffset += sizeof(struct direntry) * (wincnt - slotcount);
338
339 /*
340 * If we get here we didn't find the entry we were looking for. But
341 * that's ok if we are creating or renaming and are at the end of
342 * the pathname and the directory hasn't been removed.
343 */
344#ifdef MSDOSFS_DEBUG
345 printf("msdosfs_lookup(): op %d, refcnt %ld\n",
346 nameiop, dp->de_refcnt);
347 printf(" slotcount %d, slotoffset %d\n",
348 slotcount, slotoffset);
349#endif
350 if ((nameiop == CREATE || nameiop == RENAME) &&
351 (flags & ISLASTCN) && dp->de_refcnt != 0) {
352 /*
353 * Access for write is interpreted as allowing
354 * creation of files in the directory.
355 */
356 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread);
357 if (error)
358 return (error);
359 /*
360 * Return an indication of where the new directory
361 * entry should be put.
362 */
363 dp->de_fndoffset = slotoffset;
364 dp->de_fndcnt = wincnt - 1;
365
366 /*
367 * We return with the directory locked, so that
368 * the parameters we set up above will still be
369 * valid if we actually decide to do a direnter().
370 * We return ni_vp == NULL to indicate that the entry
371 * does not currently exist; we leave a pointer to
372 * the (locked) directory inode in ndp->ni_dvp.
373 * The pathname buffer is saved so that the name
374 * can be obtained later.
375 *
376 * NB - if the directory is unlocked, then this
377 * information cannot be used.
378 */
379 cnp->cn_flags |= SAVENAME;
380 return (EJUSTRETURN);
381 }
382#if 0
383 /*
384 * Insert name into cache (as non-existent) if appropriate.
385 *
386 * XXX Negative caching is broken for msdosfs because the name
387 * cache doesn't understand peculiarities such as case insensitivity
388 * and 8.3 filenames. Hence, it may not invalidate all negative
389 * entries if a file with this name is later created.
390 */
391 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
392 cache_enter(vdp, *vpp, cnp);
393#endif
394 return (ENOENT);
395
396found:
397 /*
398 * NOTE: We still have the buffer with matched directory entry at
399 * this point.
400 */
401 isadir = dep->deAttributes & ATTR_DIRECTORY;
402 scn = getushort(dep->deStartCluster);
403 if (FAT32(pmp)) {
404 scn |= getushort(dep->deHighClust) << 16;
405 if (scn == pmp->pm_rootdirblk) {
406 /*
407 * There should actually be 0 here.
408 * Just ignore the error.
409 */
410 scn = MSDOSFSROOT;
411 }
412 }
413
414 if (isadir) {
415 cluster = scn;
416 if (cluster == MSDOSFSROOT)
417 blkoff = MSDOSFSROOT_OFS;
418 else
419 blkoff = 0;
420 } else if (cluster == MSDOSFSROOT)
421 blkoff = diroff;
422
423 /*
424 * Now release buf to allow deget to read the entry again.
425 * Reserving it here and giving it to deget could result
426 * in a deadlock.
427 */
428 brelse(bp);
429 bp = 0;
430
431foundroot:
432 /*
433 * If we entered at foundroot, then we are looking for the . or ..
434 * entry of the filesystems root directory. isadir and scn were
435 * setup before jumping here. And, bp is already null.
436 */
437 if (FAT32(pmp) && scn == MSDOSFSROOT)
438 scn = pmp->pm_rootdirblk;
439
440 /*
441 * If deleting, and at end of pathname, return
442 * parameters which can be used to remove file.
443 */
444 if (nameiop == DELETE && (flags & ISLASTCN)) {
445 /*
446 * Don't allow deleting the root.
447 */
448 if (blkoff == MSDOSFSROOT_OFS)
449 return EROFS; /* really? XXX */
450
451 /*
452 * Write access to directory required to delete files.
453 */
454 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread);
455 if (error)
456 return (error);
457
458 /*
459 * Return pointer to current entry in dp->i_offset.
460 * Save directory inode pointer in ndp->ni_dvp for dirremove().
461 */
462 if (dp->de_StartCluster == scn && isadir) { /* "." */
463 VREF(vdp);
464 *vpp = vdp;
465 return (0);
466 }
467 error = deget(pmp, cluster, blkoff, &tdp);
468 if (error)
469 return (error);
470 *vpp = DETOV(tdp);
471 return (0);
472 }
473
474 /*
475 * If rewriting (RENAME), return the inode and the
476 * information required to rewrite the present directory
477 * Must get inode of directory entry to verify it's a
478 * regular file, or empty directory.
479 */
480 if (nameiop == RENAME && (flags & ISLASTCN)) {
481 if (blkoff == MSDOSFSROOT_OFS)
482 return EROFS; /* really? XXX */
483
484 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread);
485 if (error)
486 return (error);
487
488 /*
489 * Careful about locking second inode.
490 * This can only occur if the target is ".".
491 */
492 if (dp->de_StartCluster == scn && isadir)
493 return (EISDIR);
494
495 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
496 return (error);
497 *vpp = DETOV(tdp);
498 cnp->cn_flags |= SAVENAME;
499 return (0);
500 }
501
502 /*
503 * Step through the translation in the name. We do not `vput' the
504 * directory because we may need it again if a symbolic link
505 * is relative to the current directory. Instead we save it
506 * unlocked as "pdp". We must get the target inode before unlocking
507 * the directory to insure that the inode will not be removed
508 * before we get it. We prevent deadlock by always fetching
509 * inodes from the root, moving down the directory tree. Thus
510 * when following backward pointers ".." we must unlock the
511 * parent directory before getting the requested directory.
512 * There is a potential race condition here if both the current
513 * and parent directories are removed before the VFS_VGET for the
514 * inode associated with ".." returns. We hope that this occurs
515 * infrequently since we cannot avoid this race condition without
516 * implementing a sophisticated deadlock detection algorithm.
517 * Note also that this simple deadlock detection scheme will not
518 * work if the filesystem has any hard links other than ".."
519 * that point backwards in the directory structure.
520 */
521 pdp = vdp;
522 if (flags & ISDOTDOT) {
523 VOP_UNLOCK(pdp, 0, td);
524 error = deget(pmp, cluster, blkoff, &tdp);
525 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
526 if (error)
527 return (error);
528 *vpp = DETOV(tdp);
529 } else if (dp->de_StartCluster == scn && isadir) {
530 VREF(vdp); /* we want ourself, ie "." */
531 *vpp = vdp;
532 } else {
533 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
534 return (error);
535 *vpp = DETOV(tdp);
536 }
537
538 /*
539 * Insert name into cache if appropriate.
540 */
541 if (cnp->cn_flags & MAKEENTRY)
542 cache_enter(vdp, *vpp, cnp);
543 return (0);
544}
545
546/*
547 * dep - directory entry to copy into the directory
548 * ddep - directory to add to
549 * depp - return the address of the denode for the created directory entry
550 * if depp != 0
551 * cnp - componentname needed for Win95 long filenames
552 */
553int
554createde(dep, ddep, depp, cnp)
555 struct denode *dep;
556 struct denode *ddep;
557 struct denode **depp;
558 struct componentname *cnp;
559{
560 int error;
561 u_long dirclust, diroffset;
562 struct direntry *ndep;
563 struct msdosfsmount *pmp = ddep->de_pmp;
564 struct buf *bp;
565 daddr_t bn;
566 int blsize;
567
568#ifdef MSDOSFS_DEBUG
569 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
570 dep, ddep, depp, cnp);
571#endif
572
573 /*
574 * If no space left in the directory then allocate another cluster
575 * and chain it onto the end of the file. There is one exception
576 * to this. That is, if the root directory has no more space it
577 * can NOT be expanded. extendfile() checks for and fails attempts
578 * to extend the root directory. We just return an error in that
579 * case.
580 */
581 if (ddep->de_fndoffset >= ddep->de_FileSize) {
582 diroffset = ddep->de_fndoffset + sizeof(struct direntry)
583 - ddep->de_FileSize;
584 dirclust = de_clcount(pmp, diroffset);
585 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR);
586 if (error) {
587 (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED, NULL);
588 return error;
589 }
590
591 /*
592 * Update the size of the directory
593 */
594 ddep->de_FileSize += de_cn2off(pmp, dirclust);
595 }
596
597 /*
598 * We just read in the cluster with space. Copy the new directory
599 * entry in. Then write it to disk. NOTE: DOS directories
600 * do not get smaller as clusters are emptied.
601 */
602 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset),
603 &bn, &dirclust, &blsize);
604 if (error)
605 return error;
606 diroffset = ddep->de_fndoffset;
607 if (dirclust != MSDOSFSROOT)
608 diroffset &= pmp->pm_crbomask;
609 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) {
610 brelse(bp);
611 return error;
612 }
613 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
614
615 DE_EXTERNALIZE(ndep, dep);
616
617 /*
618 * Now write the Win95 long name
619 */
620 if (ddep->de_fndcnt > 0) {
621 u_int8_t chksum = winChksum(ndep);
622 const u_char *un = (const u_char *)cnp->cn_nameptr;
623 int unlen = cnp->cn_namelen;
624 int cnt = 1;
625
626 while (--ddep->de_fndcnt >= 0) {
627 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) {
628 if ((error = bwrite(bp)) != 0)
629 return error;
630
631 ddep->de_fndoffset -= sizeof(struct direntry);
632 error = pcbmap(ddep,
633 de_cluster(pmp,
634 ddep->de_fndoffset),
635 &bn, 0, &blsize);
636 if (error)
637 return error;
638
639 error = bread(pmp->pm_devvp, bn, blsize,
640 NOCRED, &bp);
641 if (error) {
642 brelse(bp);
643 return error;
644 }
645 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
646 } else {
647 ndep--;
648 ddep->de_fndoffset -= sizeof(struct direntry);
649 }
650 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
651 cnt++, chksum, pmp))
652 break;
653 }
654 }
655
656 if ((error = bwrite(bp)) != 0)
657 return error;
658
659 /*
660 * If they want us to return with the denode gotten.
661 */
662 if (depp) {
663 if (dep->de_Attributes & ATTR_DIRECTORY) {
664 dirclust = dep->de_StartCluster;
665 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)
666 dirclust = MSDOSFSROOT;
667 if (dirclust == MSDOSFSROOT)
668 diroffset = MSDOSFSROOT_OFS;
669 else
670 diroffset = 0;
671 }
672 return deget(pmp, dirclust, diroffset, depp);
673 }
674
675 return 0;
676}
677
678/*
679 * Be sure a directory is empty except for "." and "..". Return 1 if empty,
680 * return 0 if not empty or error.
681 */
682int
683dosdirempty(dep)
684 struct denode *dep;
685{
686 int blsize;
687 int error;
688 u_long cn;
689 daddr_t bn;
690 struct buf *bp;
691 struct msdosfsmount *pmp = dep->de_pmp;
692 struct direntry *dentp;
693
694 /*
695 * Since the filesize field in directory entries for a directory is
696 * zero, we just have to feel our way through the directory until
697 * we hit end of file.
698 */
699 for (cn = 0;; cn++) {
700 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
701 if (error == E2BIG)
702 return (1); /* it's empty */
703 return (0);
704 }
705 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
706 if (error) {
707 brelse(bp);
708 return (0);
709 }
710 for (dentp = (struct direntry *)bp->b_data;
711 (char *)dentp < bp->b_data + blsize;
712 dentp++) {
713 if (dentp->deName[0] != SLOT_DELETED &&
714 (dentp->deAttributes & ATTR_VOLUME) == 0) {
715 /*
716 * In dos directories an entry whose name
717 * starts with SLOT_EMPTY (0) starts the
718 * beginning of the unused part of the
719 * directory, so we can just return that it
720 * is empty.
721 */
722 if (dentp->deName[0] == SLOT_EMPTY) {
723 brelse(bp);
724 return (1);
725 }
726 /*
727 * Any names other than "." and ".." in a
728 * directory mean it is not empty.
729 */
730 if (bcmp(dentp->deName, ". ", 11) &&
731 bcmp(dentp->deName, ".. ", 11)) {
732 brelse(bp);
733#ifdef MSDOSFS_DEBUG
734 printf("dosdirempty(): entry found %02x, %02x\n",
735 dentp->deName[0], dentp->deName[1]);
736#endif
737 return (0); /* not empty */
738 }
739 }
740 }
741 brelse(bp);
742 }
743 /* NOTREACHED */
744}
745
746/*
747 * Check to see if the directory described by target is in some
748 * subdirectory of source. This prevents something like the following from
749 * succeeding and leaving a bunch or files and directories orphaned. mv
750 * /a/b/c /a/b/c/d/e/f Where c and f are directories.
751 *
752 * source - the inode for /a/b/c
753 * target - the inode for /a/b/c/d/e/f
754 *
755 * Returns 0 if target is NOT a subdirectory of source.
756 * Otherwise returns a non-zero error number.
757 * The target inode is always unlocked on return.
758 */
759int
760doscheckpath(source, target)
761 struct denode *source;
762 struct denode *target;
763{
764 daddr_t scn;
765 struct msdosfsmount *pmp;
766 struct direntry *ep;
767 struct denode *dep;
768 struct buf *bp = NULL;
769 int error = 0;
770
771 dep = target;
772 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
773 (source->de_Attributes & ATTR_DIRECTORY) == 0) {
774 error = ENOTDIR;
775 goto out;
776 }
777 if (dep->de_StartCluster == source->de_StartCluster) {
778 error = EEXIST;
779 goto out;
780 }
781 if (dep->de_StartCluster == MSDOSFSROOT)
782 goto out;
783 pmp = dep->de_pmp;
784#ifdef DIAGNOSTIC
785 if (pmp != source->de_pmp)
786 panic("doscheckpath: source and target on different filesystems");
787#endif
788 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)
789 goto out;
790
791 for (;;) {
792 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
793 error = ENOTDIR;
794 break;
795 }
796 scn = dep->de_StartCluster;
797 error = bread(pmp->pm_devvp, cntobn(pmp, scn),
798 pmp->pm_bpcluster, NOCRED, &bp);
799 if (error)
800 break;
801
802 ep = (struct direntry *) bp->b_data + 1;
803 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
804 bcmp(ep->deName, ".. ", 11) != 0) {
805 error = ENOTDIR;
806 break;
807 }
808 scn = getushort(ep->deStartCluster);
809 if (FAT32(pmp))
810 scn |= getushort(ep->deHighClust) << 16;
811
812 if (scn == source->de_StartCluster) {
813 error = EINVAL;
814 break;
815 }
816 if (scn == MSDOSFSROOT)
817 break;
818 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) {
819 /*
820 * scn should be 0 in this case,
821 * but we silently ignore the error.
822 */
823 break;
824 }
825
826 vput(DETOV(dep));
827 brelse(bp);
828 bp = NULL;
829 /* NOTE: deget() clears dep on error */
830 if ((error = deget(pmp, scn, 0, &dep)) != 0)
831 break;
832 }
833out:;
834 if (bp)
835 brelse(bp);
836 if (error == ENOTDIR)
837 printf("doscheckpath(): .. not a directory?\n");
838 if (dep != NULL)
839 vput(DETOV(dep));
840 return (error);
841}
842
843/*
844 * Read in the disk block containing the directory entry (dirclu, dirofs)
845 * and return the address of the buf header, and the address of the
846 * directory entry within the block.
847 */
848int
849readep(pmp, dirclust, diroffset, bpp, epp)
850 struct msdosfsmount *pmp;
851 u_long dirclust, diroffset;
852 struct buf **bpp;
853 struct direntry **epp;
854{
855 int error;
856 daddr_t bn;
857 int blsize;
858
859 blsize = pmp->pm_bpcluster;
860 if (dirclust == MSDOSFSROOT
861 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize)
862 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask;
863 bn = detobn(pmp, dirclust, diroffset);
864 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) {
865 brelse(*bpp);
866 *bpp = NULL;
867 return (error);
868 }
869 if (epp)
870 *epp = bptoep(pmp, *bpp, diroffset);
871 return (0);
872}
873
874/*
875 * Read in the disk block containing the directory entry dep came from and
876 * return the address of the buf header, and the address of the directory
877 * entry within the block.
878 */
879int
880readde(dep, bpp, epp)
881 struct denode *dep;
882 struct buf **bpp;
883 struct direntry **epp;
884{
885
886 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
887 bpp, epp));
888}
889
890/*
891 * Remove a directory entry. At this point the file represented by the
892 * directory entry to be removed is still full length until noone has it
893 * open. When the file no longer being used msdosfs_inactive() is called
894 * and will truncate the file to 0 length. When the vnode containing the
895 * denode is needed for some other purpose by VFS it will call
896 * msdosfs_reclaim() which will remove the denode from the denode cache.
897 */
898int
899removede(pdep, dep)
900 struct denode *pdep; /* directory where the entry is removed */
901 struct denode *dep; /* file to be removed */
902{
903 int error;
904 struct direntry *ep;
905 struct buf *bp;
906 daddr_t bn;
907 int blsize;
908 struct msdosfsmount *pmp = pdep->de_pmp;
909 u_long offset = pdep->de_fndoffset;
910
911#ifdef MSDOSFS_DEBUG
912 printf("removede(): filename %s, dep %p, offset %08lx\n",
913 dep->de_Name, dep, offset);
914#endif
915
916 dep->de_refcnt--;
917 offset += sizeof(struct direntry);
918 do {
919 offset -= sizeof(struct direntry);
920 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize);
921 if (error)
922 return error;
923 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
924 if (error) {
925 brelse(bp);
926 return error;
927 }
928 ep = bptoep(pmp, bp, offset);
929 /*
930 * Check whether, if we came here the second time, i.e.
931 * when underflowing into the previous block, the last
932 * entry in this block is a longfilename entry, too.
933 */
934 if (ep->deAttributes != ATTR_WIN95
935 && offset != pdep->de_fndoffset) {
936 brelse(bp);
937 break;
938 }
939 offset += sizeof(struct direntry);
940 while (1) {
941 /*
942 * We are a bit agressive here in that we delete any Win95
943 * entries preceding this entry, not just the ones we "own".
944 * Since these presumably aren't valid anyway,
945 * there should be no harm.
946 */
947 offset -= sizeof(struct direntry);
948 ep--->deName[0] = SLOT_DELETED;
949 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95)
950 || !(offset & pmp->pm_crbomask)
951 || ep->deAttributes != ATTR_WIN95)
952 break;
953 }
954 if ((error = bwrite(bp)) != 0)
955 return error;
956 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95)
957 && !(offset & pmp->pm_crbomask)
958 && offset);
959 return 0;
960}
961
962/*
963 * Create a unique DOS name in dvp
964 */
965int
966uniqdosname(dep, cnp, cp)
967 struct denode *dep;
968 struct componentname *cnp;
969 u_char *cp;
970{
971 struct msdosfsmount *pmp = dep->de_pmp;
972 struct direntry *dentp;
973 int gen;
974 int blsize;
975 u_long cn;
976 daddr_t bn;
977 struct buf *bp;
978 int error;
979
980 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
981 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
982 cnp->cn_namelen, 0, pmp) ? 0 : EINVAL);
983
984 for (gen = 1;; gen++) {
985 /*
986 * Generate DOS name with generation number
987 */
988 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
989 cnp->cn_namelen, gen, pmp))
990 return gen == 1 ? EINVAL : EEXIST;
991
992 /*
993 * Now look for a dir entry with this exact name
994 */
995 for (cn = error = 0; !error; cn++) {
996 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
997 if (error == E2BIG) /* EOF reached and not found */
998 return 0;
999 return error;
1000 }
1001 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
1002 if (error) {
1003 brelse(bp);
1004 return error;
1005 }
1006 for (dentp = (struct direntry *)bp->b_data;
1007 (char *)dentp < bp->b_data + blsize;
1008 dentp++) {
1009 if (dentp->deName[0] == SLOT_EMPTY) {
1010 /*
1011 * Last used entry and not found
1012 */
1013 brelse(bp);
1014 return 0;
1015 }
1016 /*
1017 * Ignore volume labels and Win95 entries
1018 */
1019 if (dentp->deAttributes & ATTR_VOLUME)
1020 continue;
1021 if (!bcmp(dentp->deName, cp, 11)) {
1022 error = EEXIST;
1023 break;
1024 }
1025 }
1026 brelse(bp);
1027 }
1028 }
1029}
1030
1031/*
1032 * Find any Win'95 long filename entry in directory dep
1033 */
1034int
1035findwin95(dep)
1036 struct denode *dep;
1037{
1038 struct msdosfsmount *pmp = dep->de_pmp;
1039 struct direntry *dentp;
1040 int blsize, win95;
1041 u_long cn;
1042 daddr_t bn;
1043 struct buf *bp;
1044
1045 win95 = 1;
1046 /*
1047 * Read through the directory looking for Win'95 entries
1048 * Note: Error currently handled just as EOF XXX
1049 */
1050 for (cn = 0;; cn++) {
1051 if (pcbmap(dep, cn, &bn, 0, &blsize))
1052 return (win95);
1053 if (bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) {
1054 brelse(bp);
1055 return (win95);
1056 }
1057 for (dentp = (struct direntry *)bp->b_data;
1058 (char *)dentp < bp->b_data + blsize;
1059 dentp++) {
1060 if (dentp->deName[0] == SLOT_EMPTY) {
1061 /*
1062 * Last used entry and not found
1063 */
1064 brelse(bp);
1065 return (win95);
1066 }
1067 if (dentp->deName[0] == SLOT_DELETED) {
1068 /*
1069 * Ignore deleted files
1070 * Note: might be an indication of Win'95 anyway XXX
1071 */
1072 continue;
1073 }
1074 if (dentp->deAttributes == ATTR_WIN95) {
1075 brelse(bp);
1076 return 1;
1077 }
1078 win95 = 0;
1079 }
1080 brelse(bp);
1081 }
1082}
| 63
64/*
65 * When we search a directory the blocks containing directory entries are
66 * read and examined. The directory entries contain information that would
67 * normally be in the inode of a unix filesystem. This means that some of
68 * a directory's contents may also be in memory resident denodes (sort of
69 * an inode). This can cause problems if we are searching while some other
70 * process is modifying a directory. To prevent one process from accessing
71 * incompletely modified directory information we depend upon being the
72 * sole owner of a directory block. bread/brelse provide this service.
73 * This being the case, when a process modifies a directory it must first
74 * acquire the disk block that contains the directory entry to be modified.
75 * Then update the disk block and the denode, and then write the disk block
76 * out to disk. This way disk blocks containing directory entries and in
77 * memory denode's will be in synch.
78 */
79int
80msdosfs_lookup(ap)
81 struct vop_cachedlookup_args /* {
82 struct vnode *a_dvp;
83 struct vnode **a_vpp;
84 struct componentname *a_cnp;
85 } */ *ap;
86{
87 struct vnode *vdp = ap->a_dvp;
88 struct vnode **vpp = ap->a_vpp;
89 struct componentname *cnp = ap->a_cnp;
90 daddr_t bn;
91 int error;
92 int slotcount;
93 int slotoffset = 0;
94 int frcn;
95 u_long cluster;
96 int blkoff;
97 int diroff;
98 int blsize;
99 int isadir; /* ~0 if found direntry is a directory */
100 u_long scn; /* starting cluster number */
101 struct vnode *pdp;
102 struct denode *dp;
103 struct denode *tdp;
104 struct msdosfsmount *pmp;
105 struct buf *bp = 0;
106 struct direntry *dep = NULL;
107 u_char dosfilename[12];
108 int flags = cnp->cn_flags;
109 int nameiop = cnp->cn_nameiop;
110 struct thread *td = cnp->cn_thread;
111 int unlen;
112
113 int wincnt = 1;
114 int chksum = -1, chksum_ok;
115 int olddos = 1;
116
117#ifdef MSDOSFS_DEBUG
118 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr);
119#endif
120 dp = VTODE(vdp);
121 pmp = dp->de_pmp;
122 *vpp = NULL;
123#ifdef MSDOSFS_DEBUG
124 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n",
125 vdp, dp, dp->de_Attributes);
126#endif
127
128 /*
129 * If they are going after the . or .. entry in the root directory,
130 * they won't find it. DOS filesystems don't have them in the root
131 * directory. So, we fake it. deget() is in on this scam too.
132 */
133 if ((vdp->v_vflag & VV_ROOT) && cnp->cn_nameptr[0] == '.' &&
134 (cnp->cn_namelen == 1 ||
135 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
136 isadir = ATTR_DIRECTORY;
137 scn = MSDOSFSROOT;
138#ifdef MSDOSFS_DEBUG
139 printf("msdosfs_lookup(): looking for . or .. in root directory\n");
140#endif
141 cluster = MSDOSFSROOT;
142 blkoff = MSDOSFSROOT_OFS;
143 goto foundroot;
144 }
145
146 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename,
147 cnp->cn_namelen, 0, pmp)) {
148 case 0:
149 return (EINVAL);
150 case 1:
151 break;
152 case 2:
153 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
154 cnp->cn_namelen, pmp) + 1;
155 break;
156 case 3:
157 olddos = 0;
158 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
159 cnp->cn_namelen, pmp) + 1;
160 break;
161 }
162 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) {
163 wincnt = 1;
164 olddos = 1;
165 }
166 unlen = winLenFixup(cnp->cn_nameptr, cnp->cn_namelen);
167
168 /*
169 * Suppress search for slots unless creating
170 * file and at end of pathname, in which case
171 * we watch for a place to put the new file in
172 * case it doesn't already exist.
173 */
174 slotcount = wincnt;
175 if ((nameiop == CREATE || nameiop == RENAME) &&
176 (flags & ISLASTCN))
177 slotcount = 0;
178
179#ifdef MSDOSFS_DEBUG
180 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n",
181 dosfilename, cnp->cn_namelen);
182#endif
183 /*
184 * Search the directory pointed at by vdp for the name pointed at
185 * by cnp->cn_nameptr.
186 */
187 tdp = NULL;
188 mbnambuf_init();
189 /*
190 * The outer loop ranges over the clusters that make up the
191 * directory. Note that the root directory is different from all
192 * other directories. It has a fixed number of blocks that are not
193 * part of the pool of allocatable clusters. So, we treat it a
194 * little differently. The root directory starts at "cluster" 0.
195 */
196 diroff = 0;
197 for (frcn = 0;; frcn++) {
198 error = pcbmap(dp, frcn, &bn, &cluster, &blsize);
199 if (error) {
200 if (error == E2BIG)
201 break;
202 return (error);
203 }
204 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
205 if (error) {
206 brelse(bp);
207 return (error);
208 }
209 for (blkoff = 0; blkoff < blsize;
210 blkoff += sizeof(struct direntry),
211 diroff += sizeof(struct direntry)) {
212 dep = (struct direntry *)(bp->b_data + blkoff);
213 /*
214 * If the slot is empty and we are still looking
215 * for an empty then remember this one. If the
216 * slot is not empty then check to see if it
217 * matches what we are looking for. If the slot
218 * has never been filled with anything, then the
219 * remainder of the directory has never been used,
220 * so there is no point in searching it.
221 */
222 if (dep->deName[0] == SLOT_EMPTY ||
223 dep->deName[0] == SLOT_DELETED) {
224 /*
225 * Drop memory of previous long matches
226 */
227 chksum = -1;
228 mbnambuf_init();
229
230 if (slotcount < wincnt) {
231 slotcount++;
232 slotoffset = diroff;
233 }
234 if (dep->deName[0] == SLOT_EMPTY) {
235 brelse(bp);
236 goto notfound;
237 }
238 } else {
239 /*
240 * If there wasn't enough space for our winentries,
241 * forget about the empty space
242 */
243 if (slotcount < wincnt)
244 slotcount = 0;
245
246 /*
247 * Check for Win95 long filename entry
248 */
249 if (dep->deAttributes == ATTR_WIN95) {
250 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
251 continue;
252
253 chksum = win2unixfn((struct winentry *)dep,
254 chksum,
255 pmp);
256 continue;
257 }
258
259 chksum = winChkName((const u_char *)cnp->cn_nameptr,
260 unlen,
261 chksum,
262 pmp);
263 if (chksum == -2) {
264 chksum = -1;
265 continue;
266 }
267
268 /*
269 * Ignore volume labels (anywhere, not just
270 * the root directory).
271 */
272 if (dep->deAttributes & ATTR_VOLUME) {
273 chksum = -1;
274 continue;
275 }
276
277 /*
278 * Check for a checksum or name match
279 */
280 chksum_ok = (chksum == winChksum(dep));
281 if (!chksum_ok
282 && (!olddos || bcmp(dosfilename, dep->deName, 11))) {
283 chksum = -1;
284 continue;
285 }
286#ifdef MSDOSFS_DEBUG
287 printf("msdosfs_lookup(): match blkoff %d, diroff %d\n",
288 blkoff, diroff);
289#endif
290 /*
291 * Remember where this directory
292 * entry came from for whoever did
293 * this lookup.
294 */
295 dp->de_fndoffset = diroff;
296 if (chksum_ok && nameiop == RENAME) {
297 /*
298 * Target had correct long name
299 * directory entries, reuse them
300 * as needed.
301 */
302 dp->de_fndcnt = wincnt - 1;
303 } else {
304 /*
305 * Long name directory entries
306 * not present or corrupt, can only
307 * reuse dos directory entry.
308 */
309 dp->de_fndcnt = 0;
310 }
311
312 goto found;
313 }
314 } /* for (blkoff = 0; .... */
315 /*
316 * Release the buffer holding the directory cluster just
317 * searched.
318 */
319 brelse(bp);
320 } /* for (frcn = 0; ; frcn++) */
321
322notfound:
323 /*
324 * We hold no disk buffers at this point.
325 */
326
327 /*
328 * Fixup the slot description to point to the place where
329 * we might put the new DOS direntry (putting the Win95
330 * long name entries before that)
331 */
332 if (!slotcount) {
333 slotcount = 1;
334 slotoffset = diroff;
335 }
336 if (wincnt > slotcount)
337 slotoffset += sizeof(struct direntry) * (wincnt - slotcount);
338
339 /*
340 * If we get here we didn't find the entry we were looking for. But
341 * that's ok if we are creating or renaming and are at the end of
342 * the pathname and the directory hasn't been removed.
343 */
344#ifdef MSDOSFS_DEBUG
345 printf("msdosfs_lookup(): op %d, refcnt %ld\n",
346 nameiop, dp->de_refcnt);
347 printf(" slotcount %d, slotoffset %d\n",
348 slotcount, slotoffset);
349#endif
350 if ((nameiop == CREATE || nameiop == RENAME) &&
351 (flags & ISLASTCN) && dp->de_refcnt != 0) {
352 /*
353 * Access for write is interpreted as allowing
354 * creation of files in the directory.
355 */
356 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread);
357 if (error)
358 return (error);
359 /*
360 * Return an indication of where the new directory
361 * entry should be put.
362 */
363 dp->de_fndoffset = slotoffset;
364 dp->de_fndcnt = wincnt - 1;
365
366 /*
367 * We return with the directory locked, so that
368 * the parameters we set up above will still be
369 * valid if we actually decide to do a direnter().
370 * We return ni_vp == NULL to indicate that the entry
371 * does not currently exist; we leave a pointer to
372 * the (locked) directory inode in ndp->ni_dvp.
373 * The pathname buffer is saved so that the name
374 * can be obtained later.
375 *
376 * NB - if the directory is unlocked, then this
377 * information cannot be used.
378 */
379 cnp->cn_flags |= SAVENAME;
380 return (EJUSTRETURN);
381 }
382#if 0
383 /*
384 * Insert name into cache (as non-existent) if appropriate.
385 *
386 * XXX Negative caching is broken for msdosfs because the name
387 * cache doesn't understand peculiarities such as case insensitivity
388 * and 8.3 filenames. Hence, it may not invalidate all negative
389 * entries if a file with this name is later created.
390 */
391 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
392 cache_enter(vdp, *vpp, cnp);
393#endif
394 return (ENOENT);
395
396found:
397 /*
398 * NOTE: We still have the buffer with matched directory entry at
399 * this point.
400 */
401 isadir = dep->deAttributes & ATTR_DIRECTORY;
402 scn = getushort(dep->deStartCluster);
403 if (FAT32(pmp)) {
404 scn |= getushort(dep->deHighClust) << 16;
405 if (scn == pmp->pm_rootdirblk) {
406 /*
407 * There should actually be 0 here.
408 * Just ignore the error.
409 */
410 scn = MSDOSFSROOT;
411 }
412 }
413
414 if (isadir) {
415 cluster = scn;
416 if (cluster == MSDOSFSROOT)
417 blkoff = MSDOSFSROOT_OFS;
418 else
419 blkoff = 0;
420 } else if (cluster == MSDOSFSROOT)
421 blkoff = diroff;
422
423 /*
424 * Now release buf to allow deget to read the entry again.
425 * Reserving it here and giving it to deget could result
426 * in a deadlock.
427 */
428 brelse(bp);
429 bp = 0;
430
431foundroot:
432 /*
433 * If we entered at foundroot, then we are looking for the . or ..
434 * entry of the filesystems root directory. isadir and scn were
435 * setup before jumping here. And, bp is already null.
436 */
437 if (FAT32(pmp) && scn == MSDOSFSROOT)
438 scn = pmp->pm_rootdirblk;
439
440 /*
441 * If deleting, and at end of pathname, return
442 * parameters which can be used to remove file.
443 */
444 if (nameiop == DELETE && (flags & ISLASTCN)) {
445 /*
446 * Don't allow deleting the root.
447 */
448 if (blkoff == MSDOSFSROOT_OFS)
449 return EROFS; /* really? XXX */
450
451 /*
452 * Write access to directory required to delete files.
453 */
454 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread);
455 if (error)
456 return (error);
457
458 /*
459 * Return pointer to current entry in dp->i_offset.
460 * Save directory inode pointer in ndp->ni_dvp for dirremove().
461 */
462 if (dp->de_StartCluster == scn && isadir) { /* "." */
463 VREF(vdp);
464 *vpp = vdp;
465 return (0);
466 }
467 error = deget(pmp, cluster, blkoff, &tdp);
468 if (error)
469 return (error);
470 *vpp = DETOV(tdp);
471 return (0);
472 }
473
474 /*
475 * If rewriting (RENAME), return the inode and the
476 * information required to rewrite the present directory
477 * Must get inode of directory entry to verify it's a
478 * regular file, or empty directory.
479 */
480 if (nameiop == RENAME && (flags & ISLASTCN)) {
481 if (blkoff == MSDOSFSROOT_OFS)
482 return EROFS; /* really? XXX */
483
484 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread);
485 if (error)
486 return (error);
487
488 /*
489 * Careful about locking second inode.
490 * This can only occur if the target is ".".
491 */
492 if (dp->de_StartCluster == scn && isadir)
493 return (EISDIR);
494
495 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
496 return (error);
497 *vpp = DETOV(tdp);
498 cnp->cn_flags |= SAVENAME;
499 return (0);
500 }
501
502 /*
503 * Step through the translation in the name. We do not `vput' the
504 * directory because we may need it again if a symbolic link
505 * is relative to the current directory. Instead we save it
506 * unlocked as "pdp". We must get the target inode before unlocking
507 * the directory to insure that the inode will not be removed
508 * before we get it. We prevent deadlock by always fetching
509 * inodes from the root, moving down the directory tree. Thus
510 * when following backward pointers ".." we must unlock the
511 * parent directory before getting the requested directory.
512 * There is a potential race condition here if both the current
513 * and parent directories are removed before the VFS_VGET for the
514 * inode associated with ".." returns. We hope that this occurs
515 * infrequently since we cannot avoid this race condition without
516 * implementing a sophisticated deadlock detection algorithm.
517 * Note also that this simple deadlock detection scheme will not
518 * work if the filesystem has any hard links other than ".."
519 * that point backwards in the directory structure.
520 */
521 pdp = vdp;
522 if (flags & ISDOTDOT) {
523 VOP_UNLOCK(pdp, 0, td);
524 error = deget(pmp, cluster, blkoff, &tdp);
525 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
526 if (error)
527 return (error);
528 *vpp = DETOV(tdp);
529 } else if (dp->de_StartCluster == scn && isadir) {
530 VREF(vdp); /* we want ourself, ie "." */
531 *vpp = vdp;
532 } else {
533 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
534 return (error);
535 *vpp = DETOV(tdp);
536 }
537
538 /*
539 * Insert name into cache if appropriate.
540 */
541 if (cnp->cn_flags & MAKEENTRY)
542 cache_enter(vdp, *vpp, cnp);
543 return (0);
544}
545
546/*
547 * dep - directory entry to copy into the directory
548 * ddep - directory to add to
549 * depp - return the address of the denode for the created directory entry
550 * if depp != 0
551 * cnp - componentname needed for Win95 long filenames
552 */
553int
554createde(dep, ddep, depp, cnp)
555 struct denode *dep;
556 struct denode *ddep;
557 struct denode **depp;
558 struct componentname *cnp;
559{
560 int error;
561 u_long dirclust, diroffset;
562 struct direntry *ndep;
563 struct msdosfsmount *pmp = ddep->de_pmp;
564 struct buf *bp;
565 daddr_t bn;
566 int blsize;
567
568#ifdef MSDOSFS_DEBUG
569 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
570 dep, ddep, depp, cnp);
571#endif
572
573 /*
574 * If no space left in the directory then allocate another cluster
575 * and chain it onto the end of the file. There is one exception
576 * to this. That is, if the root directory has no more space it
577 * can NOT be expanded. extendfile() checks for and fails attempts
578 * to extend the root directory. We just return an error in that
579 * case.
580 */
581 if (ddep->de_fndoffset >= ddep->de_FileSize) {
582 diroffset = ddep->de_fndoffset + sizeof(struct direntry)
583 - ddep->de_FileSize;
584 dirclust = de_clcount(pmp, diroffset);
585 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR);
586 if (error) {
587 (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED, NULL);
588 return error;
589 }
590
591 /*
592 * Update the size of the directory
593 */
594 ddep->de_FileSize += de_cn2off(pmp, dirclust);
595 }
596
597 /*
598 * We just read in the cluster with space. Copy the new directory
599 * entry in. Then write it to disk. NOTE: DOS directories
600 * do not get smaller as clusters are emptied.
601 */
602 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset),
603 &bn, &dirclust, &blsize);
604 if (error)
605 return error;
606 diroffset = ddep->de_fndoffset;
607 if (dirclust != MSDOSFSROOT)
608 diroffset &= pmp->pm_crbomask;
609 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) {
610 brelse(bp);
611 return error;
612 }
613 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
614
615 DE_EXTERNALIZE(ndep, dep);
616
617 /*
618 * Now write the Win95 long name
619 */
620 if (ddep->de_fndcnt > 0) {
621 u_int8_t chksum = winChksum(ndep);
622 const u_char *un = (const u_char *)cnp->cn_nameptr;
623 int unlen = cnp->cn_namelen;
624 int cnt = 1;
625
626 while (--ddep->de_fndcnt >= 0) {
627 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) {
628 if ((error = bwrite(bp)) != 0)
629 return error;
630
631 ddep->de_fndoffset -= sizeof(struct direntry);
632 error = pcbmap(ddep,
633 de_cluster(pmp,
634 ddep->de_fndoffset),
635 &bn, 0, &blsize);
636 if (error)
637 return error;
638
639 error = bread(pmp->pm_devvp, bn, blsize,
640 NOCRED, &bp);
641 if (error) {
642 brelse(bp);
643 return error;
644 }
645 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
646 } else {
647 ndep--;
648 ddep->de_fndoffset -= sizeof(struct direntry);
649 }
650 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
651 cnt++, chksum, pmp))
652 break;
653 }
654 }
655
656 if ((error = bwrite(bp)) != 0)
657 return error;
658
659 /*
660 * If they want us to return with the denode gotten.
661 */
662 if (depp) {
663 if (dep->de_Attributes & ATTR_DIRECTORY) {
664 dirclust = dep->de_StartCluster;
665 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)
666 dirclust = MSDOSFSROOT;
667 if (dirclust == MSDOSFSROOT)
668 diroffset = MSDOSFSROOT_OFS;
669 else
670 diroffset = 0;
671 }
672 return deget(pmp, dirclust, diroffset, depp);
673 }
674
675 return 0;
676}
677
678/*
679 * Be sure a directory is empty except for "." and "..". Return 1 if empty,
680 * return 0 if not empty or error.
681 */
682int
683dosdirempty(dep)
684 struct denode *dep;
685{
686 int blsize;
687 int error;
688 u_long cn;
689 daddr_t bn;
690 struct buf *bp;
691 struct msdosfsmount *pmp = dep->de_pmp;
692 struct direntry *dentp;
693
694 /*
695 * Since the filesize field in directory entries for a directory is
696 * zero, we just have to feel our way through the directory until
697 * we hit end of file.
698 */
699 for (cn = 0;; cn++) {
700 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
701 if (error == E2BIG)
702 return (1); /* it's empty */
703 return (0);
704 }
705 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
706 if (error) {
707 brelse(bp);
708 return (0);
709 }
710 for (dentp = (struct direntry *)bp->b_data;
711 (char *)dentp < bp->b_data + blsize;
712 dentp++) {
713 if (dentp->deName[0] != SLOT_DELETED &&
714 (dentp->deAttributes & ATTR_VOLUME) == 0) {
715 /*
716 * In dos directories an entry whose name
717 * starts with SLOT_EMPTY (0) starts the
718 * beginning of the unused part of the
719 * directory, so we can just return that it
720 * is empty.
721 */
722 if (dentp->deName[0] == SLOT_EMPTY) {
723 brelse(bp);
724 return (1);
725 }
726 /*
727 * Any names other than "." and ".." in a
728 * directory mean it is not empty.
729 */
730 if (bcmp(dentp->deName, ". ", 11) &&
731 bcmp(dentp->deName, ".. ", 11)) {
732 brelse(bp);
733#ifdef MSDOSFS_DEBUG
734 printf("dosdirempty(): entry found %02x, %02x\n",
735 dentp->deName[0], dentp->deName[1]);
736#endif
737 return (0); /* not empty */
738 }
739 }
740 }
741 brelse(bp);
742 }
743 /* NOTREACHED */
744}
745
746/*
747 * Check to see if the directory described by target is in some
748 * subdirectory of source. This prevents something like the following from
749 * succeeding and leaving a bunch or files and directories orphaned. mv
750 * /a/b/c /a/b/c/d/e/f Where c and f are directories.
751 *
752 * source - the inode for /a/b/c
753 * target - the inode for /a/b/c/d/e/f
754 *
755 * Returns 0 if target is NOT a subdirectory of source.
756 * Otherwise returns a non-zero error number.
757 * The target inode is always unlocked on return.
758 */
759int
760doscheckpath(source, target)
761 struct denode *source;
762 struct denode *target;
763{
764 daddr_t scn;
765 struct msdosfsmount *pmp;
766 struct direntry *ep;
767 struct denode *dep;
768 struct buf *bp = NULL;
769 int error = 0;
770
771 dep = target;
772 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
773 (source->de_Attributes & ATTR_DIRECTORY) == 0) {
774 error = ENOTDIR;
775 goto out;
776 }
777 if (dep->de_StartCluster == source->de_StartCluster) {
778 error = EEXIST;
779 goto out;
780 }
781 if (dep->de_StartCluster == MSDOSFSROOT)
782 goto out;
783 pmp = dep->de_pmp;
784#ifdef DIAGNOSTIC
785 if (pmp != source->de_pmp)
786 panic("doscheckpath: source and target on different filesystems");
787#endif
788 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)
789 goto out;
790
791 for (;;) {
792 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
793 error = ENOTDIR;
794 break;
795 }
796 scn = dep->de_StartCluster;
797 error = bread(pmp->pm_devvp, cntobn(pmp, scn),
798 pmp->pm_bpcluster, NOCRED, &bp);
799 if (error)
800 break;
801
802 ep = (struct direntry *) bp->b_data + 1;
803 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
804 bcmp(ep->deName, ".. ", 11) != 0) {
805 error = ENOTDIR;
806 break;
807 }
808 scn = getushort(ep->deStartCluster);
809 if (FAT32(pmp))
810 scn |= getushort(ep->deHighClust) << 16;
811
812 if (scn == source->de_StartCluster) {
813 error = EINVAL;
814 break;
815 }
816 if (scn == MSDOSFSROOT)
817 break;
818 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) {
819 /*
820 * scn should be 0 in this case,
821 * but we silently ignore the error.
822 */
823 break;
824 }
825
826 vput(DETOV(dep));
827 brelse(bp);
828 bp = NULL;
829 /* NOTE: deget() clears dep on error */
830 if ((error = deget(pmp, scn, 0, &dep)) != 0)
831 break;
832 }
833out:;
834 if (bp)
835 brelse(bp);
836 if (error == ENOTDIR)
837 printf("doscheckpath(): .. not a directory?\n");
838 if (dep != NULL)
839 vput(DETOV(dep));
840 return (error);
841}
842
843/*
844 * Read in the disk block containing the directory entry (dirclu, dirofs)
845 * and return the address of the buf header, and the address of the
846 * directory entry within the block.
847 */
848int
849readep(pmp, dirclust, diroffset, bpp, epp)
850 struct msdosfsmount *pmp;
851 u_long dirclust, diroffset;
852 struct buf **bpp;
853 struct direntry **epp;
854{
855 int error;
856 daddr_t bn;
857 int blsize;
858
859 blsize = pmp->pm_bpcluster;
860 if (dirclust == MSDOSFSROOT
861 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize)
862 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask;
863 bn = detobn(pmp, dirclust, diroffset);
864 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) {
865 brelse(*bpp);
866 *bpp = NULL;
867 return (error);
868 }
869 if (epp)
870 *epp = bptoep(pmp, *bpp, diroffset);
871 return (0);
872}
873
874/*
875 * Read in the disk block containing the directory entry dep came from and
876 * return the address of the buf header, and the address of the directory
877 * entry within the block.
878 */
879int
880readde(dep, bpp, epp)
881 struct denode *dep;
882 struct buf **bpp;
883 struct direntry **epp;
884{
885
886 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
887 bpp, epp));
888}
889
890/*
891 * Remove a directory entry. At this point the file represented by the
892 * directory entry to be removed is still full length until noone has it
893 * open. When the file no longer being used msdosfs_inactive() is called
894 * and will truncate the file to 0 length. When the vnode containing the
895 * denode is needed for some other purpose by VFS it will call
896 * msdosfs_reclaim() which will remove the denode from the denode cache.
897 */
898int
899removede(pdep, dep)
900 struct denode *pdep; /* directory where the entry is removed */
901 struct denode *dep; /* file to be removed */
902{
903 int error;
904 struct direntry *ep;
905 struct buf *bp;
906 daddr_t bn;
907 int blsize;
908 struct msdosfsmount *pmp = pdep->de_pmp;
909 u_long offset = pdep->de_fndoffset;
910
911#ifdef MSDOSFS_DEBUG
912 printf("removede(): filename %s, dep %p, offset %08lx\n",
913 dep->de_Name, dep, offset);
914#endif
915
916 dep->de_refcnt--;
917 offset += sizeof(struct direntry);
918 do {
919 offset -= sizeof(struct direntry);
920 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize);
921 if (error)
922 return error;
923 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
924 if (error) {
925 brelse(bp);
926 return error;
927 }
928 ep = bptoep(pmp, bp, offset);
929 /*
930 * Check whether, if we came here the second time, i.e.
931 * when underflowing into the previous block, the last
932 * entry in this block is a longfilename entry, too.
933 */
934 if (ep->deAttributes != ATTR_WIN95
935 && offset != pdep->de_fndoffset) {
936 brelse(bp);
937 break;
938 }
939 offset += sizeof(struct direntry);
940 while (1) {
941 /*
942 * We are a bit agressive here in that we delete any Win95
943 * entries preceding this entry, not just the ones we "own".
944 * Since these presumably aren't valid anyway,
945 * there should be no harm.
946 */
947 offset -= sizeof(struct direntry);
948 ep--->deName[0] = SLOT_DELETED;
949 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95)
950 || !(offset & pmp->pm_crbomask)
951 || ep->deAttributes != ATTR_WIN95)
952 break;
953 }
954 if ((error = bwrite(bp)) != 0)
955 return error;
956 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95)
957 && !(offset & pmp->pm_crbomask)
958 && offset);
959 return 0;
960}
961
962/*
963 * Create a unique DOS name in dvp
964 */
965int
966uniqdosname(dep, cnp, cp)
967 struct denode *dep;
968 struct componentname *cnp;
969 u_char *cp;
970{
971 struct msdosfsmount *pmp = dep->de_pmp;
972 struct direntry *dentp;
973 int gen;
974 int blsize;
975 u_long cn;
976 daddr_t bn;
977 struct buf *bp;
978 int error;
979
980 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
981 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
982 cnp->cn_namelen, 0, pmp) ? 0 : EINVAL);
983
984 for (gen = 1;; gen++) {
985 /*
986 * Generate DOS name with generation number
987 */
988 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
989 cnp->cn_namelen, gen, pmp))
990 return gen == 1 ? EINVAL : EEXIST;
991
992 /*
993 * Now look for a dir entry with this exact name
994 */
995 for (cn = error = 0; !error; cn++) {
996 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
997 if (error == E2BIG) /* EOF reached and not found */
998 return 0;
999 return error;
1000 }
1001 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
1002 if (error) {
1003 brelse(bp);
1004 return error;
1005 }
1006 for (dentp = (struct direntry *)bp->b_data;
1007 (char *)dentp < bp->b_data + blsize;
1008 dentp++) {
1009 if (dentp->deName[0] == SLOT_EMPTY) {
1010 /*
1011 * Last used entry and not found
1012 */
1013 brelse(bp);
1014 return 0;
1015 }
1016 /*
1017 * Ignore volume labels and Win95 entries
1018 */
1019 if (dentp->deAttributes & ATTR_VOLUME)
1020 continue;
1021 if (!bcmp(dentp->deName, cp, 11)) {
1022 error = EEXIST;
1023 break;
1024 }
1025 }
1026 brelse(bp);
1027 }
1028 }
1029}
1030
1031/*
1032 * Find any Win'95 long filename entry in directory dep
1033 */
1034int
1035findwin95(dep)
1036 struct denode *dep;
1037{
1038 struct msdosfsmount *pmp = dep->de_pmp;
1039 struct direntry *dentp;
1040 int blsize, win95;
1041 u_long cn;
1042 daddr_t bn;
1043 struct buf *bp;
1044
1045 win95 = 1;
1046 /*
1047 * Read through the directory looking for Win'95 entries
1048 * Note: Error currently handled just as EOF XXX
1049 */
1050 for (cn = 0;; cn++) {
1051 if (pcbmap(dep, cn, &bn, 0, &blsize))
1052 return (win95);
1053 if (bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) {
1054 brelse(bp);
1055 return (win95);
1056 }
1057 for (dentp = (struct direntry *)bp->b_data;
1058 (char *)dentp < bp->b_data + blsize;
1059 dentp++) {
1060 if (dentp->deName[0] == SLOT_EMPTY) {
1061 /*
1062 * Last used entry and not found
1063 */
1064 brelse(bp);
1065 return (win95);
1066 }
1067 if (dentp->deName[0] == SLOT_DELETED) {
1068 /*
1069 * Ignore deleted files
1070 * Note: might be an indication of Win'95 anyway XXX
1071 */
1072 continue;
1073 }
1074 if (dentp->deAttributes == ATTR_WIN95) {
1075 brelse(bp);
1076 return 1;
1077 }
1078 win95 = 0;
1079 }
1080 brelse(bp);
1081 }
1082}
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