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[dragonfly.git] / sys / vfs / msdosfs / msdosfs_lookup.c
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984263bc 1/* $FreeBSD: src/sys/msdosfs/msdosfs_lookup.c,v 1.30.2.1 2000/11/03 15:55:39 bp Exp $ */
5fd012e0 2/* $DragonFly: src/sys/vfs/msdosfs/msdosfs_lookup.c,v 1.12 2004/10/12 19:21:00 dillon Exp $ */
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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>
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54#include <sys/buf.h>
55#include <sys/vnode.h>
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56#include <sys/proc.h>
57#include <sys/namei.h>
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58#include <sys/mount.h>
59
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60#include "bpb.h"
61#include "direntry.h"
62#include "denode.h"
63#include "msdosfsmount.h"
64#include "fat.h"
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65
66/*
67 * When we search a directory the blocks containing directory entries are
68 * read and examined. The directory entries contain information that would
69 * normally be in the inode of a unix filesystem. This means that some of
70 * a directory's contents may also be in memory resident denodes (sort of
71 * an inode). This can cause problems if we are searching while some other
72 * process is modifying a directory. To prevent one process from accessing
73 * incompletely modified directory information we depend upon being the
74 * sole owner of a directory block. bread/brelse provide this service.
75 * This being the case, when a process modifies a directory it must first
76 * acquire the disk block that contains the directory entry to be modified.
77 * Then update the disk block and the denode, and then write the disk block
78 * out to disk. This way disk blocks containing directory entries and in
79 * memory denode's will be in synch.
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80 *
81 * msdosfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
82 * struct componentname *a_cnp)
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83 */
84int
4625f023 85msdosfs_lookup(struct vop_cachedlookup_args *ap)
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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 lockparent;
93 int wantparent;
94 int slotcount;
95 int slotoffset = 0;
96 int frcn;
97 u_long cluster;
98 int blkoff;
99 int diroff;
100 int blsize;
101 int isadir; /* ~0 if found direntry is a directory */
102 u_long scn; /* starting cluster number */
103 struct vnode *pdp;
104 struct denode *dp;
105 struct denode *tdp;
106 struct msdosfsmount *pmp;
107 struct buf *bp = 0;
108 struct direntry *dep = NULL;
109 u_char dosfilename[12];
110 int flags = cnp->cn_flags;
111 int nameiop = cnp->cn_nameiop;
dadab5e9 112 struct thread *td = cnp->cn_td;
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113 int unlen;
114
115 int wincnt = 1;
116 int chksum = -1;
117 int olddos = 1;
2b69e610 118 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
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119
120#ifdef MSDOSFS_DEBUG
121 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr);
122#endif
123 dp = VTODE(vdp);
124 pmp = dp->de_pmp;
125 *vpp = NULL;
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126 lockparent = flags & CNP_LOCKPARENT;
127 wantparent = flags & (CNP_LOCKPARENT | CNP_WANTPARENT);
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128#ifdef MSDOSFS_DEBUG
129 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n",
130 vdp, dp, dp->de_Attributes);
131#endif
132
133 /*
134 * If they are going after the . or .. entry in the root directory,
135 * they won't find it. DOS filesystems don't have them in the root
136 * directory. So, we fake it. deget() is in on this scam too.
137 */
138 if ((vdp->v_flag & VROOT) && cnp->cn_nameptr[0] == '.' &&
139 (cnp->cn_namelen == 1 ||
140 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) {
141 isadir = ATTR_DIRECTORY;
142 scn = MSDOSFSROOT;
143#ifdef MSDOSFS_DEBUG
144 printf("msdosfs_lookup(): looking for . or .. in root directory\n");
145#endif
146 cluster = MSDOSFSROOT;
147 blkoff = MSDOSFSROOT_OFS;
148 goto foundroot;
149 }
150
151 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename,
152 cnp->cn_namelen, 0,
153 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d,
154 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu)) {
155 case 0:
156 return (EINVAL);
157 case 1:
158 break;
159 case 2:
160 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
161 cnp->cn_namelen) + 1;
162 break;
163 case 3:
164 olddos = 0;
165 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
166 cnp->cn_namelen) + 1;
167 break;
168 }
169 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) {
170 wincnt = 1;
171 olddos = 1;
172 }
173 unlen = winLenFixup(cnp->cn_nameptr, cnp->cn_namelen);
174
175 /*
176 * Suppress search for slots unless creating
177 * file and at end of pathname, in which case
178 * we watch for a place to put the new file in
179 * case it doesn't already exist.
180 */
181 slotcount = wincnt;
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182 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) &&
183 (flags & CNP_ISLASTCN))
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184 slotcount = 0;
185
186#ifdef MSDOSFS_DEBUG
187 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n",
188 dosfilename, cnp->cn_namelen);
189#endif
190 /*
191 * Search the directory pointed at by vdp for the name pointed at
192 * by cnp->cn_nameptr.
193 */
194 tdp = NULL;
195 /*
196 * The outer loop ranges over the clusters that make up the
197 * directory. Note that the root directory is different from all
198 * other directories. It has a fixed number of blocks that are not
199 * part of the pool of allocatable clusters. So, we treat it a
200 * little differently. The root directory starts at "cluster" 0.
201 */
202 diroff = 0;
203 for (frcn = 0;; frcn++) {
204 error = pcbmap(dp, frcn, &bn, &cluster, &blsize);
205 if (error) {
206 if (error == E2BIG)
207 break;
208 return (error);
209 }
3b568787 210 error = bread(pmp->pm_devvp, bn, blsize, &bp);
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211 if (error) {
212 brelse(bp);
213 return (error);
214 }
215 for (blkoff = 0; blkoff < blsize;
216 blkoff += sizeof(struct direntry),
217 diroff += sizeof(struct direntry)) {
218 dep = (struct direntry *)(bp->b_data + blkoff);
219 /*
220 * If the slot is empty and we are still looking
221 * for an empty then remember this one. If the
222 * slot is not empty then check to see if it
223 * matches what we are looking for. If the slot
224 * has never been filled with anything, then the
225 * remainder of the directory has never been used,
226 * so there is no point in searching it.
227 */
228 if (dep->deName[0] == SLOT_EMPTY ||
229 dep->deName[0] == SLOT_DELETED) {
230 /*
231 * Drop memory of previous long matches
232 */
233 chksum = -1;
234
235 if (slotcount < wincnt) {
236 slotcount++;
237 slotoffset = diroff;
238 }
239 if (dep->deName[0] == SLOT_EMPTY) {
240 brelse(bp);
241 goto notfound;
242 }
243 } else {
244 /*
245 * If there wasn't enough space for our winentries,
246 * forget about the empty space
247 */
248 if (slotcount < wincnt)
249 slotcount = 0;
250
251 /*
252 * Check for Win95 long filename entry
253 */
254 if (dep->deAttributes == ATTR_WIN95) {
255 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
256 continue;
257
258 chksum = winChkName((const u_char *)cnp->cn_nameptr,
259 unlen,
260 (struct winentry *)dep,
261 chksum,
262 pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
263 pmp->pm_u2w,
264 pmp->pm_flags & MSDOSFSMNT_ULTABLE,
265 pmp->pm_ul);
266 continue;
267 }
268
269 /*
270 * Ignore volume labels (anywhere, not just
271 * the root directory).
272 */
273 if (dep->deAttributes & ATTR_VOLUME) {
274 chksum = -1;
275 continue;
276 }
277
278 /*
279 * Check for a checksum or name match
280 */
281 if (chksum != winChksum(dep->deName)
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 dp->de_fndcnt = wincnt - 1;
297
298 goto found;
299 }
300 } /* for (blkoff = 0; .... */
301 /*
302 * Release the buffer holding the directory cluster just
303 * searched.
304 */
305 brelse(bp);
306 } /* for (frcn = 0; ; frcn++) */
307
308notfound:
309 /*
310 * We hold no disk buffers at this point.
311 */
312
313 /*
314 * Fixup the slot description to point to the place where
315 * we might put the new DOS direntry (putting the Win95
316 * long name entries before that)
317 */
318 if (!slotcount) {
319 slotcount = 1;
320 slotoffset = diroff;
321 }
322 if (wincnt > slotcount)
323 slotoffset += sizeof(struct direntry) * (wincnt - slotcount);
324
325 /*
326 * If we get here we didn't find the entry we were looking for. But
327 * that's ok if we are creating or renaming and are at the end of
328 * the pathname and the directory hasn't been removed.
329 */
330#ifdef MSDOSFS_DEBUG
331 printf("msdosfs_lookup(): op %d, refcnt %ld\n",
332 nameiop, dp->de_refcnt);
333 printf(" slotcount %d, slotoffset %d\n",
334 slotcount, slotoffset);
335#endif
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336 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) &&
337 (flags & CNP_ISLASTCN) && dp->de_refcnt != 0) {
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338 /*
339 * Access for write is interpreted as allowing
340 * creation of files in the directory.
341 */
dadab5e9 342 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_td);
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343 if (error)
344 return (error);
345 /*
346 * Return an indication of where the new directory
347 * entry should be put.
348 */
349 dp->de_fndoffset = slotoffset;
350 dp->de_fndcnt = wincnt - 1;
351
352 /*
353 * We return with the directory locked, so that
354 * the parameters we set up above will still be
355 * valid if we actually decide to do a direnter().
356 * We return ni_vp == NULL to indicate that the entry
357 * does not currently exist; we leave a pointer to
358 * the (locked) directory inode in ndp->ni_dvp.
359 * The pathname buffer is saved so that the name
360 * can be obtained later.
361 *
362 * NB - if the directory is unlocked, then this
363 * information cannot be used.
364 */
2b69e610 365 cnp->cn_flags |= CNP_SAVENAME;
984263bc 366 if (!lockparent) {
5fd012e0 367 VOP_UNLOCK(vdp, 0, td);
2b69e610 368 cnp->cn_flags |= CNP_PDIRUNLOCK;
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369 }
370 return (EJUSTRETURN);
371 }
372 /*
373 * Insert name into cache (as non-existent) if appropriate.
374 */
2b69e610 375 if ((cnp->cn_flags & CNP_MAKEENTRY) && nameiop != NAMEI_CREATE)
21739618 376 cache_enter(vdp, *vpp, cnp);
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377 return (ENOENT);
378
379found:
380 /*
381 * NOTE: We still have the buffer with matched directory entry at
382 * this point.
383 */
384 isadir = dep->deAttributes & ATTR_DIRECTORY;
385 scn = getushort(dep->deStartCluster);
386 if (FAT32(pmp)) {
387 scn |= getushort(dep->deHighClust) << 16;
388 if (scn == pmp->pm_rootdirblk) {
389 /*
390 * There should actually be 0 here.
391 * Just ignore the error.
392 */
393 scn = MSDOSFSROOT;
394 }
395 }
396
397 if (isadir) {
398 cluster = scn;
399 if (cluster == MSDOSFSROOT)
400 blkoff = MSDOSFSROOT_OFS;
401 else
402 blkoff = 0;
403 } else if (cluster == MSDOSFSROOT)
404 blkoff = diroff;
405
406 /*
407 * Now release buf to allow deget to read the entry again.
408 * Reserving it here and giving it to deget could result
409 * in a deadlock.
410 */
411 brelse(bp);
412 bp = 0;
413
414foundroot:
415 /*
416 * If we entered at foundroot, then we are looking for the . or ..
417 * entry of the filesystems root directory. isadir and scn were
418 * setup before jumping here. And, bp is already null.
419 */
420 if (FAT32(pmp) && scn == MSDOSFSROOT)
421 scn = pmp->pm_rootdirblk;
422
423 /*
424 * If deleting, and at end of pathname, return
425 * parameters which can be used to remove file.
426 * If the wantparent flag isn't set, we return only
427 * the directory (in ndp->ni_dvp), otherwise we go
428 * on and lock the inode, being careful with ".".
429 */
2b69e610 430 if (nameiop == NAMEI_DELETE && (flags & CNP_ISLASTCN)) {
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431 /*
432 * Don't allow deleting the root.
433 */
434 if (blkoff == MSDOSFSROOT_OFS)
435 return EROFS; /* really? XXX */
436
437 /*
438 * Write access to directory required to delete files.
439 */
dadab5e9 440 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_td);
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441 if (error)
442 return (error);
443
444 /*
445 * Return pointer to current entry in dp->i_offset.
446 * Save directory inode pointer in ndp->ni_dvp for dirremove().
447 */
448 if (dp->de_StartCluster == scn && isadir) { /* "." */
597aea93 449 vref(vdp);
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450 *vpp = vdp;
451 return (0);
452 }
453 error = deget(pmp, cluster, blkoff, &tdp);
454 if (error)
455 return (error);
456 *vpp = DETOV(tdp);
457 if (!lockparent) {
5fd012e0 458 VOP_UNLOCK(vdp, 0, td);
2b69e610 459 cnp->cn_flags |= CNP_PDIRUNLOCK;
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460 }
461 return (0);
462 }
463
464 /*
465 * If rewriting (RENAME), return the inode and the
466 * information required to rewrite the present directory
467 * Must get inode of directory entry to verify it's a
468 * regular file, or empty directory.
469 */
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MD
470 if (nameiop == NAMEI_RENAME && wantparent &&
471 (flags & CNP_ISLASTCN)) {
984263bc 472 if (blkoff == MSDOSFSROOT_OFS)
2b69e610 473 return EROFS; /* really? XXX */
984263bc 474
dadab5e9 475 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_td);
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476 if (error)
477 return (error);
478
479 /*
480 * Careful about locking second inode.
481 * This can only occur if the target is ".".
482 */
483 if (dp->de_StartCluster == scn && isadir)
484 return (EISDIR);
485
486 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
487 return (error);
488 *vpp = DETOV(tdp);
2b69e610 489 cnp->cn_flags |= CNP_SAVENAME;
984263bc 490 if (!lockparent) {
5fd012e0 491 VOP_UNLOCK(vdp, 0, td);
2b69e610 492 cnp->cn_flags |= CNP_PDIRUNLOCK;
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493 }
494 return (0);
495 }
496
497 /*
498 * Step through the translation in the name. We do not `vput' the
499 * directory because we may need it again if a symbolic link
500 * is relative to the current directory. Instead we save it
501 * unlocked as "pdp". We must get the target inode before unlocking
502 * the directory to insure that the inode will not be removed
503 * before we get it. We prevent deadlock by always fetching
504 * inodes from the root, moving down the directory tree. Thus
505 * when following backward pointers ".." we must unlock the
506 * parent directory before getting the requested directory.
507 * There is a potential race condition here if both the current
508 * and parent directories are removed before the VFS_VGET for the
509 * inode associated with ".." returns. We hope that this occurs
510 * infrequently since we cannot avoid this race condition without
511 * implementing a sophisticated deadlock detection algorithm.
512 * Note also that this simple deadlock detection scheme will not
513 * work if the file system has any hard links other than ".."
514 * that point backwards in the directory structure.
515 */
516 pdp = vdp;
2b69e610 517 if (flags & CNP_ISDOTDOT) {
5fd012e0 518 VOP_UNLOCK(pdp, 0, td);
2b69e610 519 cnp->cn_flags |= CNP_PDIRUNLOCK;
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520 error = deget(pmp, cluster, blkoff, &tdp);
521 if (error) {
5fd012e0 522 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
2b69e610 523 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
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524 return (error);
525 }
2b69e610 526 if (lockparent && (flags & CNP_ISLASTCN)) {
5fd012e0 527 error = vn_lock(pdp, LK_EXCLUSIVE, td);
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528 if (error) {
529 vput(DETOV(tdp));
530 return (error);
531 }
2b69e610 532 cnp->cn_flags &= ~CNP_PDIRUNLOCK;
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533 }
534 *vpp = DETOV(tdp);
535 } else if (dp->de_StartCluster == scn && isadir) {
597aea93 536 vref(vdp); /* we want ourself, ie "." */
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537 *vpp = vdp;
538 } else {
539 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0)
540 return (error);
2b69e610 541 if (!lockparent || !(flags & CNP_ISLASTCN)) {
5fd012e0 542 VOP_UNLOCK(pdp, 0, td);
2b69e610 543 cnp->cn_flags |= CNP_PDIRUNLOCK;
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544 }
545 *vpp = DETOV(tdp);
546 }
547
548 /*
549 * Insert name into cache if appropriate.
550 */
2b69e610 551 if (cnp->cn_flags & CNP_MAKEENTRY)
21739618 552 cache_enter(vdp, *vpp, cnp);
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553 return (0);
554}
555
556/*
557 * dep - directory entry to copy into the directory
558 * ddep - directory to add to
559 * depp - return the address of the denode for the created directory entry
560 * if depp != 0
561 * cnp - componentname needed for Win95 long filenames
562 */
563int
4625f023
CP
564createde(struct denode *dep, struct denode *ddep, struct denode **depp,
565 struct componentname *cnp)
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566{
567 int error;
568 u_long dirclust, diroffset;
569 struct direntry *ndep;
570 struct msdosfsmount *pmp = ddep->de_pmp;
571 struct buf *bp;
572 daddr_t bn;
573 int blsize;
574
575#ifdef MSDOSFS_DEBUG
576 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n",
577 dep, ddep, depp, cnp);
578#endif
579
580 /*
581 * If no space left in the directory then allocate another cluster
582 * and chain it onto the end of the file. There is one exception
583 * to this. That is, if the root directory has no more space it
584 * can NOT be expanded. extendfile() checks for and fails attempts
585 * to extend the root directory. We just return an error in that
586 * case.
587 */
588 if (ddep->de_fndoffset >= ddep->de_FileSize) {
589 diroffset = ddep->de_fndoffset + sizeof(struct direntry)
590 - ddep->de_FileSize;
591 dirclust = de_clcount(pmp, diroffset);
592 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR);
593 if (error) {
3b568787 594 (void)detrunc(ddep, ddep->de_FileSize, 0, NULL);
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595 return error;
596 }
597
598 /*
599 * Update the size of the directory
600 */
601 ddep->de_FileSize += de_cn2off(pmp, dirclust);
602 }
603
604 /*
605 * We just read in the cluster with space. Copy the new directory
606 * entry in. Then write it to disk. NOTE: DOS directories
607 * do not get smaller as clusters are emptied.
608 */
609 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset),
610 &bn, &dirclust, &blsize);
611 if (error)
612 return error;
613 diroffset = ddep->de_fndoffset;
614 if (dirclust != MSDOSFSROOT)
615 diroffset &= pmp->pm_crbomask;
3b568787 616 if ((error = bread(pmp->pm_devvp, bn, blsize, &bp)) != 0) {
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617 brelse(bp);
618 return error;
619 }
620 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
621
622 DE_EXTERNALIZE(ndep, dep);
623
624 /*
625 * Now write the Win95 long name
626 */
627 if (ddep->de_fndcnt > 0) {
628 u_int8_t chksum = winChksum(ndep->deName);
629 const u_char *un = (const u_char *)cnp->cn_nameptr;
630 int unlen = cnp->cn_namelen;
631 int cnt = 1;
632
633 while (--ddep->de_fndcnt >= 0) {
634 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) {
635 if ((error = bwrite(bp)) != 0)
636 return error;
637
638 ddep->de_fndoffset -= sizeof(struct direntry);
639 error = pcbmap(ddep,
640 de_cluster(pmp,
641 ddep->de_fndoffset),
642 &bn, 0, &blsize);
643 if (error)
644 return error;
645
3b568787 646 error = bread(pmp->pm_devvp, bn, blsize, &bp);
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647 if (error) {
648 brelse(bp);
649 return error;
650 }
651 ndep = bptoep(pmp, bp, ddep->de_fndoffset);
652 } else {
653 ndep--;
654 ddep->de_fndoffset -= sizeof(struct direntry);
655 }
656 if (!unix2winfn(un, unlen, (struct winentry *)ndep,
657 cnt++, chksum,
658 pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
659 pmp->pm_u2w))
660 break;
661 }
662 }
663
664 if ((error = bwrite(bp)) != 0)
665 return error;
666
667 /*
668 * If they want us to return with the denode gotten.
669 */
670 if (depp) {
671 if (dep->de_Attributes & ATTR_DIRECTORY) {
672 dirclust = dep->de_StartCluster;
673 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)
674 dirclust = MSDOSFSROOT;
675 if (dirclust == MSDOSFSROOT)
676 diroffset = MSDOSFSROOT_OFS;
677 else
678 diroffset = 0;
679 }
680 return deget(pmp, dirclust, diroffset, depp);
681 }
682
683 return 0;
684}
685
686/*
687 * Be sure a directory is empty except for "." and "..". Return 1 if empty,
688 * return 0 if not empty or error.
689 */
690int
4625f023 691dosdirempty(struct denode *dep)
984263bc
MD
692{
693 int blsize;
694 int error;
695 u_long cn;
696 daddr_t bn;
697 struct buf *bp;
698 struct msdosfsmount *pmp = dep->de_pmp;
699 struct direntry *dentp;
700
701 /*
702 * Since the filesize field in directory entries for a directory is
703 * zero, we just have to feel our way through the directory until
704 * we hit end of file.
705 */
706 for (cn = 0;; cn++) {
707 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
708 if (error == E2BIG)
709 return (1); /* it's empty */
710 return (0);
711 }
3b568787 712 error = bread(pmp->pm_devvp, bn, blsize, &bp);
984263bc
MD
713 if (error) {
714 brelse(bp);
715 return (0);
716 }
717 for (dentp = (struct direntry *)bp->b_data;
718 (char *)dentp < bp->b_data + blsize;
719 dentp++) {
720 if (dentp->deName[0] != SLOT_DELETED &&
721 (dentp->deAttributes & ATTR_VOLUME) == 0) {
722 /*
723 * In dos directories an entry whose name
724 * starts with SLOT_EMPTY (0) starts the
725 * beginning of the unused part of the
726 * directory, so we can just return that it
727 * is empty.
728 */
729 if (dentp->deName[0] == SLOT_EMPTY) {
730 brelse(bp);
731 return (1);
732 }
733 /*
734 * Any names other than "." and ".." in a
735 * directory mean it is not empty.
736 */
737 if (bcmp(dentp->deName, ". ", 11) &&
738 bcmp(dentp->deName, ".. ", 11)) {
739 brelse(bp);
740#ifdef MSDOSFS_DEBUG
741 printf("dosdirempty(): entry found %02x, %02x\n",
742 dentp->deName[0], dentp->deName[1]);
743#endif
744 return (0); /* not empty */
745 }
746 }
747 }
748 brelse(bp);
749 }
750 /* NOTREACHED */
751}
752
753/*
754 * Check to see if the directory described by target is in some
755 * subdirectory of source. This prevents something like the following from
756 * succeeding and leaving a bunch or files and directories orphaned. mv
757 * /a/b/c /a/b/c/d/e/f Where c and f are directories.
758 *
759 * source - the inode for /a/b/c
760 * target - the inode for /a/b/c/d/e/f
761 *
762 * Returns 0 if target is NOT a subdirectory of source.
763 * Otherwise returns a non-zero error number.
764 * The target inode is always unlocked on return.
765 */
766int
4625f023 767doscheckpath(struct denode *source, struct denode *target)
984263bc
MD
768{
769 daddr_t scn;
770 struct msdosfsmount *pmp;
771 struct direntry *ep;
772 struct denode *dep;
773 struct buf *bp = NULL;
774 int error = 0;
775
776 dep = target;
777 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 ||
778 (source->de_Attributes & ATTR_DIRECTORY) == 0) {
779 error = ENOTDIR;
780 goto out;
781 }
782 if (dep->de_StartCluster == source->de_StartCluster) {
783 error = EEXIST;
784 goto out;
785 }
786 if (dep->de_StartCluster == MSDOSFSROOT)
787 goto out;
788 pmp = dep->de_pmp;
789#ifdef DIAGNOSTIC
790 if (pmp != source->de_pmp)
791 panic("doscheckpath: source and target on different filesystems");
792#endif
793 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)
794 goto out;
795
796 for (;;) {
797 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
798 error = ENOTDIR;
799 break;
800 }
801 scn = dep->de_StartCluster;
802 error = bread(pmp->pm_devvp, cntobn(pmp, scn),
3b568787 803 pmp->pm_bpcluster, &bp);
984263bc
MD
804 if (error)
805 break;
806
807 ep = (struct direntry *) bp->b_data + 1;
808 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 ||
809 bcmp(ep->deName, ".. ", 11) != 0) {
810 error = ENOTDIR;
811 break;
812 }
813 scn = getushort(ep->deStartCluster);
814 if (FAT32(pmp))
815 scn |= getushort(ep->deHighClust) << 16;
816
817 if (scn == source->de_StartCluster) {
818 error = EINVAL;
819 break;
820 }
821 if (scn == MSDOSFSROOT)
822 break;
823 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) {
824 /*
825 * scn should be 0 in this case,
826 * but we silently ignore the error.
827 */
828 break;
829 }
830
831 vput(DETOV(dep));
832 brelse(bp);
833 bp = NULL;
834 /* NOTE: deget() clears dep on error */
835 if ((error = deget(pmp, scn, 0, &dep)) != 0)
836 break;
837 }
838out:;
839 if (bp)
840 brelse(bp);
841 if (error == ENOTDIR)
842 printf("doscheckpath(): .. not a directory?\n");
843 if (dep != NULL)
844 vput(DETOV(dep));
845 return (error);
846}
847
848/*
849 * Read in the disk block containing the directory entry (dirclu, dirofs)
850 * and return the address of the buf header, and the address of the
851 * directory entry within the block.
852 */
853int
4625f023
CP
854readep(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
855 struct buf **bpp, struct direntry **epp)
984263bc
MD
856{
857 int error;
858 daddr_t bn;
859 int blsize;
860
861 blsize = pmp->pm_bpcluster;
862 if (dirclust == MSDOSFSROOT
863 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize)
864 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask;
865 bn = detobn(pmp, dirclust, diroffset);
3b568787 866 if ((error = bread(pmp->pm_devvp, bn, blsize, bpp)) != 0) {
984263bc
MD
867 brelse(*bpp);
868 *bpp = NULL;
869 return (error);
870 }
871 if (epp)
872 *epp = bptoep(pmp, *bpp, diroffset);
873 return (0);
874}
875
876/*
877 * Read in the disk block containing the directory entry dep came from and
878 * return the address of the buf header, and the address of the directory
879 * entry within the block.
880 */
881int
4625f023 882readde(struct denode *dep, struct buf **bpp, struct direntry **epp)
984263bc 883{
984263bc
MD
884 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset,
885 bpp, epp));
886}
887
888/*
889 * Remove a directory entry. At this point the file represented by the
890 * directory entry to be removed is still full length until noone has it
891 * open. When the file no longer being used msdosfs_inactive() is called
892 * and will truncate the file to 0 length. When the vnode containing the
893 * denode is needed for some other purpose by VFS it will call
894 * msdosfs_reclaim() which will remove the denode from the denode cache.
895 */
896int
4625f023
CP
897removede(struct denode *pdep, /* directory where the entry is removed */
898 struct denode *dep) /* file to be removed */
984263bc
MD
899{
900 int error;
901 struct direntry *ep;
902 struct buf *bp;
903 daddr_t bn;
904 int blsize;
905 struct msdosfsmount *pmp = pdep->de_pmp;
906 u_long offset = pdep->de_fndoffset;
907
908#ifdef MSDOSFS_DEBUG
909 printf("removede(): filename %s, dep %p, offset %08lx\n",
910 dep->de_Name, dep, offset);
911#endif
912
913 dep->de_refcnt--;
914 offset += sizeof(struct direntry);
915 do {
916 offset -= sizeof(struct direntry);
917 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize);
918 if (error)
919 return error;
3b568787 920 error = bread(pmp->pm_devvp, bn, blsize, &bp);
984263bc
MD
921 if (error) {
922 brelse(bp);
923 return error;
924 }
925 ep = bptoep(pmp, bp, offset);
926 /*
927 * Check whether, if we came here the second time, i.e.
928 * when underflowing into the previous block, the last
929 * entry in this block is a longfilename entry, too.
930 */
931 if (ep->deAttributes != ATTR_WIN95
932 && offset != pdep->de_fndoffset) {
933 brelse(bp);
934 break;
935 }
936 offset += sizeof(struct direntry);
937 while (1) {
938 /*
939 * We are a bit agressive here in that we delete any Win95
940 * entries preceding this entry, not just the ones we "own".
941 * Since these presumably aren't valid anyway,
942 * there should be no harm.
943 */
944 offset -= sizeof(struct direntry);
945 ep--->deName[0] = SLOT_DELETED;
946 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95)
947 || !(offset & pmp->pm_crbomask)
948 || ep->deAttributes != ATTR_WIN95)
949 break;
950 }
951 if ((error = bwrite(bp)) != 0)
952 return error;
953 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95)
954 && !(offset & pmp->pm_crbomask)
955 && offset);
956 return 0;
957}
958
959/*
960 * Create a unique DOS name in dvp
961 */
962int
4625f023 963uniqdosname(struct denode *dep, struct componentname *cnp, u_char *cp)
984263bc
MD
964{
965 struct msdosfsmount *pmp = dep->de_pmp;
966 struct direntry *dentp;
967 int gen;
968 int blsize;
969 u_long cn;
970 daddr_t bn;
971 struct buf *bp;
972 int error;
973
974 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
975 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
976 cnp->cn_namelen, 0,
977 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d,
978 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu) ?
979 0 : EINVAL);
980
981 for (gen = 1;; gen++) {
982 /*
983 * Generate DOS name with generation number
984 */
985 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp,
986 cnp->cn_namelen, gen,
987 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d,
988 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu))
989 return gen == 1 ? EINVAL : EEXIST;
990
991 /*
992 * Now look for a dir entry with this exact name
993 */
994 for (cn = error = 0; !error; cn++) {
995 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) {
996 if (error == E2BIG) /* EOF reached and not found */
997 return 0;
998 return error;
999 }
3b568787 1000 error = bread(pmp->pm_devvp, bn, blsize, &bp);
984263bc
MD
1001 if (error) {
1002 brelse(bp);
1003 return error;
1004 }
1005 for (dentp = (struct direntry *)bp->b_data;
1006 (char *)dentp < bp->b_data + blsize;
1007 dentp++) {
1008 if (dentp->deName[0] == SLOT_EMPTY) {
1009 /*
1010 * Last used entry and not found
1011 */
1012 brelse(bp);
1013 return 0;
1014 }
1015 /*
1016 * Ignore volume labels and Win95 entries
1017 */
1018 if (dentp->deAttributes & ATTR_VOLUME)
1019 continue;
1020 if (!bcmp(dentp->deName, cp, 11)) {
1021 error = EEXIST;
1022 break;
1023 }
1024 }
1025 brelse(bp);
1026 }
1027 }
1028}
1029
1030/*
1031 * Find any Win'95 long filename entry in directory dep
1032 */
1033int
4625f023 1034findwin95(struct denode *dep)
984263bc
MD
1035{
1036 struct msdosfsmount *pmp = dep->de_pmp;
1037 struct direntry *dentp;
1038 int blsize, win95;
1039 u_long cn;
1040 daddr_t bn;
1041 struct buf *bp;
1042
1043 win95 = 1;
1044 /*
1045 * Read through the directory looking for Win'95 entries
1046 * Note: Error currently handled just as EOF XXX
1047 */
1048 for (cn = 0;; cn++) {
1049 if (pcbmap(dep, cn, &bn, 0, &blsize))
1050 return (win95);
3b568787 1051 if (bread(pmp->pm_devvp, bn, blsize, &bp)) {
984263bc
MD
1052 brelse(bp);
1053 return (win95);
1054 }
1055 for (dentp = (struct direntry *)bp->b_data;
1056 (char *)dentp < bp->b_data + blsize;
1057 dentp++) {
1058 if (dentp->deName[0] == SLOT_EMPTY) {
1059 /*
1060 * Last used entry and not found
1061 */
1062 brelse(bp);
1063 return (win95);
1064 }
1065 if (dentp->deName[0] == SLOT_DELETED) {
1066 /*
1067 * Ignore deleted files
1068 * Note: might be an indication of Win'95 anyway XXX
1069 */
1070 continue;
1071 }
1072 if (dentp->deAttributes == ATTR_WIN95) {
1073 brelse(bp);
1074 return 1;
1075 }
1076 win95 = 0;
1077 }
1078 brelse(bp);
1079 }
1080}