proc->thread stage 3.5: Add an IO_CORE flag so coda doesn't have to dig
[dragonfly.git] / sys / vfs / msdosfs / msdosfs_lookup.c
CommitLineData
984263bc 1/* $FreeBSD: src/sys/msdosfs/msdosfs_lookup.c,v 1.30.2.1 2000/11/03 15:55:39 bp Exp $ */
1de703da 2/* $DragonFly: src/sys/vfs/msdosfs/msdosfs_lookup.c,v 1.2 2003/06/17 04:28:47 dillon Exp $ */
984263bc
MD
3/* $NetBSD: msdosfs_lookup.c,v 1.37 1997/11/17 15:36:54 ws Exp $ */
4
5/*-
6 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
7 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
8 * All rights reserved.
9 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by TooLs GmbH.
22 * 4. The name of TooLs GmbH may not be used to endorse or promote products
23 * derived from this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
34 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36/*
37 * Written by Paul Popelka (paulp@uts.amdahl.com)
38 *
39 * You can do anything you want with this software, just don't say you wrote
40 * it, and don't remove this notice.
41 *
42 * This software is provided "as is".
43 *
44 * The author supplies this software to be publicly redistributed on the
45 * understanding that the author is not responsible for the correct
46 * functioning of this software in any circumstances and is not liable for
47 * any damages caused by this software.
48 *
49 * October 1992
50 */
51
52#include <sys/param.h>
53#include <sys/systm.h>
54#include <sys/namei.h>
55#include <sys/buf.h>
56#include <sys/vnode.h>
57#include <sys/mount.h>
58
59#include <msdosfs/bpb.h>
60#include <msdosfs/direntry.h>
61#include <msdosfs/denode.h>
62#include <msdosfs/msdosfsmount.h>
63#include <msdosfs/fat.h>
64
65/*
66 * When we search a directory the blocks containing directory entries are
67 * read and examined. The directory entries contain information that would
68 * normally be in the inode of a unix filesystem. This means that some of
69 * a directory's contents may also be in memory resident denodes (sort of
70 * an inode). This can cause problems if we are searching while some other
71 * process is modifying a directory. To prevent one process from accessing
72 * incompletely modified directory information we depend upon being the
73 * sole owner of a directory block. bread/brelse provide this service.
74 * This being the case, when a process modifies a directory it must first
75 * acquire the disk block that contains the directory entry to be modified.
76 * Then update the disk block and the denode, and then write the disk block
77 * out to disk. This way disk blocks containing directory entries and in
78 * memory denode's will be in synch.
79 */
80int
81msdosfs_lookup(ap)
82 struct vop_cachedlookup_args /* {
83 struct vnode *a_dvp;
84 struct vnode **a_vpp;
85 struct componentname *a_cnp;
86 } */ *ap;
87{
88 struct vnode *vdp = ap->a_dvp;
89 struct vnode **vpp = ap->a_vpp;
90 struct componentname *cnp = ap->a_cnp;
91 daddr_t bn;
92 int error;
93 int lockparent;
94 int wantparent;
95 int slotcount;
96 int slotoffset = 0;
97 int frcn;
98 u_long cluster;
99 int blkoff;
100 int diroff;
101 int blsize;
102 int isadir; /* ~0 if found direntry is a directory */
103 u_long scn; /* starting cluster number */
104 struct vnode *pdp;
105 struct denode *dp;
106 struct denode *tdp;
107 struct msdosfsmount *pmp;
108 struct buf *bp = 0;
109 struct direntry *dep = NULL;
110 u_char dosfilename[12];
111 int flags = cnp->cn_flags;
112 int nameiop = cnp->cn_nameiop;
113 struct proc *p = cnp->cn_proc;
114 int unlen;
115
116 int wincnt = 1;
117 int chksum = -1;
118 int olddos = 1;
119 cnp->cn_flags &= ~PDIRUNLOCK;
120
121#ifdef MSDOSFS_DEBUG
122 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr);
123#endif
124 dp = VTODE(vdp);
125 pmp = dp->de_pmp;
126 *vpp = NULL;
127 lockparent = flags & LOCKPARENT;
128 wantparent = flags & (LOCKPARENT | WANTPARENT);
129#ifdef MSDOSFS_DEBUG
130 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n",
131 vdp, dp, dp->de_Attributes);
132#endif
133
134 /*
135 * If they are going after the . or .. entry in the root directory,
136 * they won't find it. DOS filesystems don't have them in the root
137 * directory. So, we fake it. deget() is in on this scam too.
138 */
139 if ((vdp->v_flag & VROOT) && cnp->cn_nameptr[0] == '.' &&
140 (cnp->cn_namelen == 1 ||
141 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
142 isadir = ATTR_DIRECTORY;
143 scn = MSDOSFSROOT;
144#ifdef MSDOSFS_DEBUG
145 printf("msdosfs_lookup(): looking for . or .. in root directory\n");
146#endif
147 cluster = MSDOSFSROOT;
148 blkoff = MSDOSFSROOT_OFS;
149 goto foundroot;
150 }
151
152 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename,
153 cnp->cn_namelen, 0,
154 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d,
155 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu)) {
156 case 0:
157 return (EINVAL);
158 case 1:
159 break;
160 case 2:
161 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
162 cnp->cn_namelen) + 1;
163 break;
164 case 3:
165 olddos = 0;
166 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
167 cnp->cn_namelen) + 1;
168 break;
169 }
170 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) {
171 wincnt = 1;
172 olddos = 1;
173 }
174 unlen = winLenFixup(cnp->cn_nameptr, cnp->cn_namelen);
175
176 /*
177 * Suppress search for slots unless creating
178 * file and at end of pathname, in which case
179 * we watch for a place to put the new file in
180 * case it doesn't already exist.
181 */
182 slotcount = wincnt;
183 if ((nameiop == CREATE || nameiop == RENAME) &&
184 (flags & ISLASTCN))
185 slotcount = 0;
186
187#ifdef MSDOSFS_DEBUG
188 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n",
189 dosfilename, cnp->cn_namelen);
190#endif
191 /*
192 * Search the directory pointed at by vdp for the name pointed at
193 * by cnp->cn_nameptr.
194 */
195 tdp = NULL;
196 /*
197 * The outer loop ranges over the clusters that make up the
198 * directory. Note that the root directory is different from all
199 * other directories. It has a fixed number of blocks that are not
200 * part of the pool of allocatable clusters. So, we treat it a
201 * little differently. The root directory starts at "cluster" 0.
202 */
203 diroff = 0;
204 for (frcn = 0;; frcn++) {
205 error = pcbmap(dp, frcn, &bn, &cluster, &blsize);
206 if (error) {
207 if (error == E2BIG)
208 break;
209 return (error);
210 }
211 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
212 if (error) {
213 brelse(bp);
214 return (error);
215 }
216 for (blkoff = 0; blkoff < blsize;
217 blkoff += sizeof(struct direntry),
218 diroff += sizeof(struct direntry)) {
219 dep = (struct direntry *)(bp->b_data + blkoff);
220 /*
221 * If the slot is empty and we are still looking
222 * for an empty then remember this one. If the
223 * slot is not empty then check to see if it
224 * matches what we are looking for. If the slot
225 * has never been filled with anything, then the
226 * remainder of the directory has never been used,
227 * so there is no point in searching it.
228 */
229 if (dep->deName[0] == SLOT_EMPTY ||
230 dep->deName[0] == SLOT_DELETED) {
231 /*
232 * Drop memory of previous long matches
233 */
234 chksum = -1;
235
236 if (slotcount < wincnt) {
237 slotcount++;
238 slotoffset = diroff;
239 }
240 if (dep->deName[0] == SLOT_EMPTY) {
241 brelse(bp);
242 goto notfound;
243 }
244 } else {
245 /*
246 * If there wasn't enough space for our winentries,
247 * forget about the empty space
248 */
249 if (slotcount < wincnt)
250 slotcount = 0;
251
252 /*
253 * Check for Win95 long filename entry
254 */
255 if (dep->deAttributes == ATTR_WIN95) {
256 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
257 continue;
258
259 chksum = winChkName((const u_char *)cnp->cn_nameptr,
260 unlen,
261 (struct winentry *)dep,
262 chksum,
263 pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
264 pmp->pm_u2w,
265 pmp->pm_flags & MSDOSFSMNT_ULTABLE,
266 pmp->pm_ul);
267 continue;
268 }
269
270 /*
271 * Ignore volume labels (anywhere, not just
272 * the root directory).
273 */
274 if (dep->deAttributes & ATTR_VOLUME) {
275 chksum = -1;
276 continue;
277 }
278
279 /*
280 * Check for a checksum or name match
281 */
282 if (chksum != winChksum(dep->deName)
283 && (!olddos || bcmp(dosfilename, dep->deName, 11))) {
284 chksum = -1;
285 continue;
286 }
287#ifdef MSDOSFS_DEBUG
288 printf("msdosfs_lookup(): match blkoff %d, diroff %d\n",
289 blkoff, diroff);
290#endif
291 /*
292 * Remember where this directory
293 * entry came from for whoever did
294 * this lookup.
295 */
296 dp->de_fndoffset = diroff;
297 dp->de_fndcnt = wincnt - 1;
298
299 goto found;
300 }
301 } /* for (blkoff = 0; .... */
302 /*
303 * Release the buffer holding the directory cluster just
304 * searched.
305 */
306 brelse(bp);
307 } /* for (frcn = 0; ; frcn++) */
308
309notfound:
310 /*
311 * We hold no disk buffers at this point.
312 */
313
314 /*
315 * Fixup the slot description to point to the place where
316 * we might put the new DOS direntry (putting the Win95
317 * long name entries before that)
318 */
319 if (!slotcount) {
320 slotcount = 1;
321 slotoffset = diroff;
322 }
323 if (wincnt > slotcount)
324 slotoffset += sizeof(struct direntry) * (wincnt - slotcount);
325
326 /*
327 * If we get here we didn't find the entry we were looking for. But
328 * that's ok if we are creating or renaming and are at the end of
329 * the pathname and the directory hasn't been removed.
330 */
331#ifdef MSDOSFS_DEBUG
332 printf("msdosfs_lookup(): op %d, refcnt %ld\n",
333 nameiop, dp->de_refcnt);
334 printf(" slotcount %d, slotoffset %d\n",
335 slotcount, slotoffset);
336#endif
337 if ((nameiop == CREATE || nameiop == RENAME) &&
338 (flags & ISLASTCN) && dp->de_refcnt != 0) {
339 /*
340 * Access for write is interpreted as allowing
341 * creation of files in the directory.
342 */
343 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_proc);
344 if (error)
345 return (error);
346 /*
347 * Return an indication of where the new directory
348 * entry should be put.
349 */
350 dp->de_fndoffset = slotoffset;
351 dp->de_fndcnt = wincnt - 1;
352
353 /*
354 * We return with the directory locked, so that
355 * the parameters we set up above will still be
356 * valid if we actually decide to do a direnter().
357 * We return ni_vp == NULL to indicate that the entry
358 * does not currently exist; we leave a pointer to
359 * the (locked) directory inode in ndp->ni_dvp.
360 * The pathname buffer is saved so that the name
361 * can be obtained later.
362 *
363 * NB - if the directory is unlocked, then this
364 * information cannot be used.
365 */
366 cnp->cn_flags |= SAVENAME;
367 if (!lockparent) {
368 VOP_UNLOCK(vdp, 0, p);
369 cnp->cn_flags |= PDIRUNLOCK;
370 }
371 return (EJUSTRETURN);
372 }
373 /*
374 * Insert name into cache (as non-existent) if appropriate.
375 */
376 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
377 cache_enter(vdp, *vpp, cnp);
378 return (ENOENT);
379
380found:
381 /*
382 * NOTE: We still have the buffer with matched directory entry at
383 * this point.
384 */
385 isadir = dep->deAttributes & ATTR_DIRECTORY;
386 scn = getushort(dep->deStartCluster);
387 if (FAT32(pmp)) {
388 scn |= getushort(dep->deHighClust) << 16;
389 if (scn == pmp->pm_rootdirblk) {
390 /*
391 * There should actually be 0 here.
392 * Just ignore the error.
393 */
394 scn = MSDOSFSROOT;
395 }
396 }
397
398 if (isadir) {
399 cluster = scn;
400 if (cluster == MSDOSFSROOT)
401 blkoff = MSDOSFSROOT_OFS;
402 else
403 blkoff = 0;
404 } else if (cluster == MSDOSFSROOT)
405 blkoff = diroff;
406
407 /*
408 * Now release buf to allow deget to read the entry again.
409 * Reserving it here and giving it to deget could result
410 * in a deadlock.
411 */
412 brelse(bp);
413 bp = 0;
414
415foundroot:
416 /*
417 * If we entered at foundroot, then we are looking for the . or ..
418 * entry of the filesystems root directory. isadir and scn were
419 * setup before jumping here. And, bp is already null.
420 */
421 if (FAT32(pmp) && scn == MSDOSFSROOT)
422 scn = pmp->pm_rootdirblk;
423
424 /*
425 * If deleting, and at end of pathname, return
426 * parameters which can be used to remove file.
427 * If the wantparent flag isn't set, we return only
428 * the directory (in ndp->ni_dvp), otherwise we go
429 * on and lock the inode, being careful with ".".
430 */
431 if (nameiop == DELETE && (flags & ISLASTCN)) {
432 /*
433 * Don't allow deleting the root.
434 */
435 if (blkoff == MSDOSFSROOT_OFS)
436 return EROFS; /* really? XXX */
437
438 /*
439 * Write access to directory required to delete files.
440 */
441 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_proc);
442 if (error)
443 return (error);
444
445 /*
446 * Return pointer to current entry in dp->i_offset.
447 * Save directory inode pointer in ndp->ni_dvp for dirremove().
448 */
449 if (dp->de_StartCluster == scn && isadir) { /* "." */
450 VREF(vdp);
451 *vpp = vdp;
452 return (0);
453 }
454 error = deget(pmp, cluster, blkoff, &tdp);
455 if (error)
456 return (error);
457 *vpp = DETOV(tdp);
458 if (!lockparent) {
459 VOP_UNLOCK(vdp, 0, p);
460 cnp->cn_flags |= PDIRUNLOCK;
461 }
462 return (0);
463 }
464
465 /*
466 * If rewriting (RENAME), return the inode and the
467 * information required to rewrite the present directory
468 * Must get inode of directory entry to verify it's a
469 * regular file, or empty directory.
470 */
471 if (nameiop == RENAME && wantparent &&
472 (flags & ISLASTCN)) {
473 if (blkoff == MSDOSFSROOT_OFS)
474 return EROFS; /* really? XXX */
475
476 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_proc);
477 if (error)
478 return (error);
479
480 /*
481 * Careful about locking second inode.
482 * This can only occur if the target is ".".
483 */
484 if (dp->de_StartCluster == scn && isadir)
485 return (EISDIR);
486
487 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
488 return (error);
489 *vpp = DETOV(tdp);
490 cnp->cn_flags |= SAVENAME;
491 if (!lockparent) {
492 VOP_UNLOCK(vdp, 0, p);
493 cnp->cn_flags |= PDIRUNLOCK;
494 }
495 return (0);
496 }
497
498 /*
499 * Step through the translation in the name. We do not `vput' the
500 * directory because we may need it again if a symbolic link
501 * is relative to the current directory. Instead we save it
502 * unlocked as "pdp". We must get the target inode before unlocking
503 * the directory to insure that the inode will not be removed
504 * before we get it. We prevent deadlock by always fetching
505 * inodes from the root, moving down the directory tree. Thus
506 * when following backward pointers ".." we must unlock the
507 * parent directory before getting the requested directory.
508 * There is a potential race condition here if both the current
509 * and parent directories are removed before the VFS_VGET for the
510 * inode associated with ".." returns. We hope that this occurs
511 * infrequently since we cannot avoid this race condition without
512 * implementing a sophisticated deadlock detection algorithm.
513 * Note also that this simple deadlock detection scheme will not
514 * work if the file system has any hard links other than ".."
515 * that point backwards in the directory structure.
516 */
517 pdp = vdp;
518 if (flags & ISDOTDOT) {
519 VOP_UNLOCK(pdp, 0, p);
520 cnp->cn_flags |= PDIRUNLOCK;
521 error = deget(pmp, cluster, blkoff, &tdp);
522 if (error) {
523 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, p);
524 cnp->cn_flags &= ~PDIRUNLOCK;
525 return (error);
526 }
527 if (lockparent && (flags & ISLASTCN)) {
528 error = vn_lock(pdp, LK_EXCLUSIVE, p);
529 if (error) {
530 vput(DETOV(tdp));
531 return (error);
532 }
533 cnp->cn_flags &= ~PDIRUNLOCK;
534 }
535 *vpp = DETOV(tdp);
536 } else if (dp->de_StartCluster == scn && isadir) {
537 VREF(vdp); /* we want ourself, ie "." */
538 *vpp = vdp;
539 } else {
540 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
541 return (error);
542 if (!lockparent || !(flags & ISLASTCN)) {
543 VOP_UNLOCK(pdp, 0, p);
544 cnp->cn_flags |= PDIRUNLOCK;
545 }
546 *vpp = DETOV(tdp);
547 }
548
549 /*
550 * Insert name into cache if appropriate.
551 */
552 if (cnp->cn_flags & MAKEENTRY)
553 cache_enter(vdp, *vpp, cnp);
554 return (0);
555}
556
557/*
558 * dep - directory entry to copy into the directory
559 * ddep - directory to add to
560 * depp - return the address of the denode for the created directory entry
561 * if depp != 0
562 * cnp - componentname needed for Win95 long filenames
563 */
564int
565createde(dep, ddep, depp, cnp)
566 struct denode *dep;
567 struct denode *ddep;
568 struct denode **depp;
569 struct componentname *cnp;
570{
571 int error;
572 u_long dirclust, diroffset;
573 struct direntry *ndep;
574 struct msdosfsmount *pmp = ddep->de_pmp;
575 struct buf *bp;
576 daddr_t bn;
577 int blsize;
578
579#ifdef MSDOSFS_DEBUG
580 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
581 dep, ddep, depp, cnp);
582#endif
583
584 /*
585 * If no space left in the directory then allocate another cluster
586 * and chain it onto the end of the file. There is one exception
587 * to this. That is, if the root directory has no more space it
588 * can NOT be expanded. extendfile() checks for and fails attempts
589 * to extend the root directory. We just return an error in that
590 * case.
591 */
592 if (ddep->de_fndoffset >= ddep->de_FileSize) {
593 diroffset = ddep->de_fndoffset + sizeof(struct direntry)
594 - ddep->de_FileSize;
595 dirclust = de_clcount(pmp, diroffset);
596 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR);
597 if (error) {
598 (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED, NULL);
599 return error;
600 }
601
602 /*
603 * Update the size of the directory
604 */
605 ddep->de_FileSize += de_cn2off(pmp, dirclust);
606 }
607
608 /*
609 * We just read in the cluster with space. Copy the new directory
610 * entry in. Then write it to disk. NOTE: DOS directories
611 * do not get smaller as clusters are emptied.
612 */
613 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset),
614 &bn, &dirclust, &blsize);
615 if (error)
616 return error;
617 diroffset = ddep->de_fndoffset;
618 if (dirclust != MSDOSFSROOT)
619 diroffset &= pmp->pm_crbomask;
620 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) {
621 brelse(bp);
622 return error;
623 }
624 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
625
626 DE_EXTERNALIZE(ndep, dep);
627
628 /*
629 * Now write the Win95 long name
630 */
631 if (ddep->de_fndcnt > 0) {
632 u_int8_t chksum = winChksum(ndep->deName);
633 const u_char *un = (const u_char *)cnp->cn_nameptr;
634 int unlen = cnp->cn_namelen;
635 int cnt = 1;
636
637 while (--ddep->de_fndcnt >= 0) {
638 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) {
639 if ((error = bwrite(bp)) != 0)
640 return error;
641
642 ddep->de_fndoffset -= sizeof(struct direntry);
643 error = pcbmap(ddep,
644 de_cluster(pmp,
645 ddep->de_fndoffset),
646 &bn, 0, &blsize);
647 if (error)
648 return error;
649
650 error = bread(pmp->pm_devvp, bn, blsize,
651 NOCRED, &bp);
652 if (error) {
653 brelse(bp);
654 return error;
655 }
656 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
657 } else {
658 ndep--;
659 ddep->de_fndoffset -= sizeof(struct direntry);
660 }
661 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
662 cnt++, chksum,
663 pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
664 pmp->pm_u2w))
665 break;
666 }
667 }
668
669 if ((error = bwrite(bp)) != 0)
670 return error;
671
672 /*
673 * If they want us to return with the denode gotten.
674 */
675 if (depp) {
676 if (dep->de_Attributes & ATTR_DIRECTORY) {
677 dirclust = dep->de_StartCluster;
678 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)
679 dirclust = MSDOSFSROOT;
680 if (dirclust == MSDOSFSROOT)
681 diroffset = MSDOSFSROOT_OFS;
682 else
683 diroffset = 0;
684 }
685 return deget(pmp, dirclust, diroffset, depp);
686 }
687
688 return 0;
689}
690
691/*
692 * Be sure a directory is empty except for "." and "..". Return 1 if empty,
693 * return 0 if not empty or error.
694 */
695int
696dosdirempty(dep)
697 struct denode *dep;
698{
699 int blsize;
700 int error;
701 u_long cn;
702 daddr_t bn;
703 struct buf *bp;
704 struct msdosfsmount *pmp = dep->de_pmp;
705 struct direntry *dentp;
706
707 /*
708 * Since the filesize field in directory entries for a directory is
709 * zero, we just have to feel our way through the directory until
710 * we hit end of file.
711 */
712 for (cn = 0;; cn++) {
713 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
714 if (error == E2BIG)
715 return (1); /* it's empty */
716 return (0);
717 }
718 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
719 if (error) {
720 brelse(bp);
721 return (0);
722 }
723 for (dentp = (struct direntry *)bp->b_data;
724 (char *)dentp < bp->b_data + blsize;
725 dentp++) {
726 if (dentp->deName[0] != SLOT_DELETED &&
727 (dentp->deAttributes & ATTR_VOLUME) == 0) {
728 /*
729 * In dos directories an entry whose name
730 * starts with SLOT_EMPTY (0) starts the
731 * beginning of the unused part of the
732 * directory, so we can just return that it
733 * is empty.
734 */
735 if (dentp->deName[0] == SLOT_EMPTY) {
736 brelse(bp);
737 return (1);
738 }
739 /*
740 * Any names other than "." and ".." in a
741 * directory mean it is not empty.
742 */
743 if (bcmp(dentp->deName, ". ", 11) &&
744 bcmp(dentp->deName, ".. ", 11)) {
745 brelse(bp);
746#ifdef MSDOSFS_DEBUG
747 printf("dosdirempty(): entry found %02x, %02x\n",
748 dentp->deName[0], dentp->deName[1]);
749#endif
750 return (0); /* not empty */
751 }
752 }
753 }
754 brelse(bp);
755 }
756 /* NOTREACHED */
757}
758
759/*
760 * Check to see if the directory described by target is in some
761 * subdirectory of source. This prevents something like the following from
762 * succeeding and leaving a bunch or files and directories orphaned. mv
763 * /a/b/c /a/b/c/d/e/f Where c and f are directories.
764 *
765 * source - the inode for /a/b/c
766 * target - the inode for /a/b/c/d/e/f
767 *
768 * Returns 0 if target is NOT a subdirectory of source.
769 * Otherwise returns a non-zero error number.
770 * The target inode is always unlocked on return.
771 */
772int
773doscheckpath(source, target)
774 struct denode *source;
775 struct denode *target;
776{
777 daddr_t scn;
778 struct msdosfsmount *pmp;
779 struct direntry *ep;
780 struct denode *dep;
781 struct buf *bp = NULL;
782 int error = 0;
783
784 dep = target;
785 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
786 (source->de_Attributes & ATTR_DIRECTORY) == 0) {
787 error = ENOTDIR;
788 goto out;
789 }
790 if (dep->de_StartCluster == source->de_StartCluster) {
791 error = EEXIST;
792 goto out;
793 }
794 if (dep->de_StartCluster == MSDOSFSROOT)
795 goto out;
796 pmp = dep->de_pmp;
797#ifdef DIAGNOSTIC
798 if (pmp != source->de_pmp)
799 panic("doscheckpath: source and target on different filesystems");
800#endif
801 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)
802 goto out;
803
804 for (;;) {
805 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
806 error = ENOTDIR;
807 break;
808 }
809 scn = dep->de_StartCluster;
810 error = bread(pmp->pm_devvp, cntobn(pmp, scn),
811 pmp->pm_bpcluster, NOCRED, &bp);
812 if (error)
813 break;
814
815 ep = (struct direntry *) bp->b_data + 1;
816 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
817 bcmp(ep->deName, ".. ", 11) != 0) {
818 error = ENOTDIR;
819 break;
820 }
821 scn = getushort(ep->deStartCluster);
822 if (FAT32(pmp))
823 scn |= getushort(ep->deHighClust) << 16;
824
825 if (scn == source->de_StartCluster) {
826 error = EINVAL;
827 break;
828 }
829 if (scn == MSDOSFSROOT)
830 break;
831 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) {
832 /*
833 * scn should be 0 in this case,
834 * but we silently ignore the error.
835 */
836 break;
837 }
838
839 vput(DETOV(dep));
840 brelse(bp);
841 bp = NULL;
842 /* NOTE: deget() clears dep on error */
843 if ((error = deget(pmp, scn, 0, &dep)) != 0)
844 break;
845 }
846out:;
847 if (bp)
848 brelse(bp);
849 if (error == ENOTDIR)
850 printf("doscheckpath(): .. not a directory?\n");
851 if (dep != NULL)
852 vput(DETOV(dep));
853 return (error);
854}
855
856/*
857 * Read in the disk block containing the directory entry (dirclu, dirofs)
858 * and return the address of the buf header, and the address of the
859 * directory entry within the block.
860 */
861int
862readep(pmp, dirclust, diroffset, bpp, epp)
863 struct msdosfsmount *pmp;
864 u_long dirclust, diroffset;
865 struct buf **bpp;
866 struct direntry **epp;
867{
868 int error;
869 daddr_t bn;
870 int blsize;
871
872 blsize = pmp->pm_bpcluster;
873 if (dirclust == MSDOSFSROOT
874 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize)
875 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask;
876 bn = detobn(pmp, dirclust, diroffset);
877 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) {
878 brelse(*bpp);
879 *bpp = NULL;
880 return (error);
881 }
882 if (epp)
883 *epp = bptoep(pmp, *bpp, diroffset);
884 return (0);
885}
886
887/*
888 * Read in the disk block containing the directory entry dep came from and
889 * return the address of the buf header, and the address of the directory
890 * entry within the block.
891 */
892int
893readde(dep, bpp, epp)
894 struct denode *dep;
895 struct buf **bpp;
896 struct direntry **epp;
897{
898
899 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
900 bpp, epp));
901}
902
903/*
904 * Remove a directory entry. At this point the file represented by the
905 * directory entry to be removed is still full length until noone has it
906 * open. When the file no longer being used msdosfs_inactive() is called
907 * and will truncate the file to 0 length. When the vnode containing the
908 * denode is needed for some other purpose by VFS it will call
909 * msdosfs_reclaim() which will remove the denode from the denode cache.
910 */
911int
912removede(pdep, dep)
913 struct denode *pdep; /* directory where the entry is removed */
914 struct denode *dep; /* file to be removed */
915{
916 int error;
917 struct direntry *ep;
918 struct buf *bp;
919 daddr_t bn;
920 int blsize;
921 struct msdosfsmount *pmp = pdep->de_pmp;
922 u_long offset = pdep->de_fndoffset;
923
924#ifdef MSDOSFS_DEBUG
925 printf("removede(): filename %s, dep %p, offset %08lx\n",
926 dep->de_Name, dep, offset);
927#endif
928
929 dep->de_refcnt--;
930 offset += sizeof(struct direntry);
931 do {
932 offset -= sizeof(struct direntry);
933 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize);
934 if (error)
935 return error;
936 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
937 if (error) {
938 brelse(bp);
939 return error;
940 }
941 ep = bptoep(pmp, bp, offset);
942 /*
943 * Check whether, if we came here the second time, i.e.
944 * when underflowing into the previous block, the last
945 * entry in this block is a longfilename entry, too.
946 */
947 if (ep->deAttributes != ATTR_WIN95
948 && offset != pdep->de_fndoffset) {
949 brelse(bp);
950 break;
951 }
952 offset += sizeof(struct direntry);
953 while (1) {
954 /*
955 * We are a bit agressive here in that we delete any Win95
956 * entries preceding this entry, not just the ones we "own".
957 * Since these presumably aren't valid anyway,
958 * there should be no harm.
959 */
960 offset -= sizeof(struct direntry);
961 ep--->deName[0] = SLOT_DELETED;
962 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95)
963 || !(offset & pmp->pm_crbomask)
964 || ep->deAttributes != ATTR_WIN95)
965 break;
966 }
967 if ((error = bwrite(bp)) != 0)
968 return error;
969 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95)
970 && !(offset & pmp->pm_crbomask)
971 && offset);
972 return 0;
973}
974
975/*
976 * Create a unique DOS name in dvp
977 */
978int
979uniqdosname(dep, cnp, cp)
980 struct denode *dep;
981 struct componentname *cnp;
982 u_char *cp;
983{
984 struct msdosfsmount *pmp = dep->de_pmp;
985 struct direntry *dentp;
986 int gen;
987 int blsize;
988 u_long cn;
989 daddr_t bn;
990 struct buf *bp;
991 int error;
992
993 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
994 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
995 cnp->cn_namelen, 0,
996 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d,
997 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu) ?
998 0 : EINVAL);
999
1000 for (gen = 1;; gen++) {
1001 /*
1002 * Generate DOS name with generation number
1003 */
1004 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
1005 cnp->cn_namelen, gen,
1006 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d,
1007 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu))
1008 return gen == 1 ? EINVAL : EEXIST;
1009
1010 /*
1011 * Now look for a dir entry with this exact name
1012 */
1013 for (cn = error = 0; !error; cn++) {
1014 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
1015 if (error == E2BIG) /* EOF reached and not found */
1016 return 0;
1017 return error;
1018 }
1019 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
1020 if (error) {
1021 brelse(bp);
1022 return error;
1023 }
1024 for (dentp = (struct direntry *)bp->b_data;
1025 (char *)dentp < bp->b_data + blsize;
1026 dentp++) {
1027 if (dentp->deName[0] == SLOT_EMPTY) {
1028 /*
1029 * Last used entry and not found
1030 */
1031 brelse(bp);
1032 return 0;
1033 }
1034 /*
1035 * Ignore volume labels and Win95 entries
1036 */
1037 if (dentp->deAttributes & ATTR_VOLUME)
1038 continue;
1039 if (!bcmp(dentp->deName, cp, 11)) {
1040 error = EEXIST;
1041 break;
1042 }
1043 }
1044 brelse(bp);
1045 }
1046 }
1047}
1048
1049/*
1050 * Find any Win'95 long filename entry in directory dep
1051 */
1052int
1053findwin95(dep)
1054 struct denode *dep;
1055{
1056 struct msdosfsmount *pmp = dep->de_pmp;
1057 struct direntry *dentp;
1058 int blsize, win95;
1059 u_long cn;
1060 daddr_t bn;
1061 struct buf *bp;
1062
1063 win95 = 1;
1064 /*
1065 * Read through the directory looking for Win'95 entries
1066 * Note: Error currently handled just as EOF XXX
1067 */
1068 for (cn = 0;; cn++) {
1069 if (pcbmap(dep, cn, &bn, 0, &blsize))
1070 return (win95);
1071 if (bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) {
1072 brelse(bp);
1073 return (win95);
1074 }
1075 for (dentp = (struct direntry *)bp->b_data;
1076 (char *)dentp < bp->b_data + blsize;
1077 dentp++) {
1078 if (dentp->deName[0] == SLOT_EMPTY) {
1079 /*
1080 * Last used entry and not found
1081 */
1082 brelse(bp);
1083 return (win95);
1084 }
1085 if (dentp->deName[0] == SLOT_DELETED) {
1086 /*
1087 * Ignore deleted files
1088 * Note: might be an indication of Win'95 anyway XXX
1089 */
1090 continue;
1091 }
1092 if (dentp->deAttributes == ATTR_WIN95) {
1093 brelse(bp);
1094 return 1;
1095 }
1096 win95 = 0;
1097 }
1098 brelse(bp);
1099 }
1100}