1 /* $FreeBSD: releng/11.0/sys/fs/msdosfs/msdosfs_denode.c 276887 2015-01-09 14:50:08Z emaste $ */
2 /* $NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $ */
3
4 /*-
5 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
6 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7 * All rights reserved.
8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by TooLs GmbH.
21 * 4. The name of TooLs GmbH may not be used to endorse or promote products
22 * derived from this software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35 /*-
36 * Written by Paul Popelka (paulp@uts.amdahl.com)
37 *
38 * You can do anything you want with this software, just don't say you wrote
39 * it, and don't remove this notice.
40 *
41 * This software is provided "as is".
42 *
43 * The author supplies this software to be publicly redistributed on the
44 * understanding that the author is not responsible for the correct
45 * functioning of this software in any circumstances and is not liable for
46 * any damages caused by this software.
47 *
48 * October 1992
49 */
50
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/buf.h>
54 #include <sys/clock.h>
55 #include <sys/kernel.h>
56 #include <sys/malloc.h>
57 #include <sys/mount.h>
58 #include <sys/vnode.h>
59
60 #include <vm/vm.h>
61 #include <vm/vm_extern.h>
62
63 #include <fs/msdosfs/bpb.h>
64 #include <fs/msdosfs/direntry.h>
65 #include <fs/msdosfs/denode.h>
66 #include <fs/msdosfs/fat.h>
67 #include <fs/msdosfs/msdosfsmount.h>
68
69 static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part");
70
71 static int
72 de_vncmpf(struct vnode *vp, void *arg)
73 {
74 struct denode *de;
75 uint64_t *a;
76
77 a = arg;
78 de = VTODE(vp);
79 return (de->de_inode != *a);
80 }
81
82 /*
83 * If deget() succeeds it returns with the gotten denode locked().
84 *
85 * pmp - address of msdosfsmount structure of the filesystem containing
86 * the denode of interest. The address of
87 * the msdosfsmount structure are used.
88 * dirclust - which cluster bp contains, if dirclust is 0 (root directory)
89 * diroffset is relative to the beginning of the root directory,
90 * otherwise it is cluster relative.
91 * diroffset - offset past begin of cluster of denode we want
92 * depp - returns the address of the gotten denode.
93 */
94 int
95 deget(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
96 struct denode **depp)
97 {
98 int error;
99 uint64_t inode;
100 struct mount *mntp = pmp->pm_mountp;
101 struct direntry *direntptr;
102 struct denode *ldep;
103 struct vnode *nvp, *xvp;
104 struct buf *bp;
105
106 #ifdef MSDOSFS_DEBUG
107 printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
108 pmp, dirclust, diroffset, depp);
109 #endif
110
111 /*
112 * On FAT32 filesystems, root is a (more or less) normal
113 * directory
114 */
115 if (FAT32(pmp) && dirclust == MSDOSFSROOT)
116 dirclust = pmp->pm_rootdirblk;
117
118 /*
119 * See if the denode is in the denode cache. Use the location of
120 * the directory entry to compute the hash value. For subdir use
121 * address of "." entry. For root dir (if not FAT32) use cluster
122 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
123 *
124 * NOTE: The check for de_refcnt > 0 below insures the denode being
125 * examined does not represent an unlinked but still open file.
126 * These files are not to be accessible even when the directory
127 * entry that represented the file happens to be reused while the
128 * deleted file is still open.
129 */
130 inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset;
131
132 error = vfs_hash_get(mntp, inode, LK_EXCLUSIVE, curthread, &nvp,
133 de_vncmpf, &inode);
134 if (error)
135 return (error);
136 if (nvp != NULL) {
137 *depp = VTODE(nvp);
138 KASSERT((*depp)->de_dirclust == dirclust, ("wrong dirclust"));
139 KASSERT((*depp)->de_diroffset == diroffset, ("wrong diroffset"));
140 return (0);
141 }
142 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO);
143
144 /*
145 * Directory entry was not in cache, have to create a vnode and
146 * copy it from the passed disk buffer.
147 */
148 /* getnewvnode() does a VREF() on the vnode */
149 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp);
150 if (error) {
151 *depp = NULL;
152 free(ldep, M_MSDOSFSNODE);
153 return error;
154 }
155 nvp->v_data = ldep;
156 ldep->de_vnode = nvp;
157 ldep->de_flag = 0;
158 ldep->de_dirclust = dirclust;
159 ldep->de_diroffset = diroffset;
160 ldep->de_inode = inode;
161 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL);
162 fc_purge(ldep, 0); /* init the fat cache for this denode */
163 error = insmntque(nvp, mntp);
164 if (error != 0) {
165 free(ldep, M_MSDOSFSNODE);
166 *depp = NULL;
167 return (error);
168 }
169 error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp,
170 de_vncmpf, &inode);
171 if (error) {
172 *depp = NULL;
173 return (error);
174 }
175 if (xvp != NULL) {
176 *depp = xvp->v_data;
177 return (0);
178 }
179
180 ldep->de_pmp = pmp;
181 ldep->de_refcnt = 1;
182 /*
183 * Copy the directory entry into the denode area of the vnode.
184 */
185 if ((dirclust == MSDOSFSROOT
186 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
187 && diroffset == MSDOSFSROOT_OFS) {
188 /*
189 * Directory entry for the root directory. There isn't one,
190 * so we manufacture one. We should probably rummage
191 * through the root directory and find a label entry (if it
192 * exists), and then use the time and date from that entry
193 * as the time and date for the root denode.
194 */
195 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
196
197 ldep->de_Attributes = ATTR_DIRECTORY;
198 ldep->de_LowerCase = 0;
199 if (FAT32(pmp))
200 ldep->de_StartCluster = pmp->pm_rootdirblk;
201 /* de_FileSize will be filled in further down */
202 else {
203 ldep->de_StartCluster = MSDOSFSROOT;
204 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
205 }
206 /*
207 * fill in time and date so that fattime2timespec() doesn't
208 * spit up when called from msdosfs_getattr() with root
209 * denode
210 */
211 ldep->de_CHun = 0;
212 ldep->de_CTime = 0x0000; /* 00:00:00 */
213 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
214 | (1 << DD_DAY_SHIFT);
215 /* Jan 1, 1980 */
216 ldep->de_ADate = ldep->de_CDate;
217 ldep->de_MTime = ldep->de_CTime;
218 ldep->de_MDate = ldep->de_CDate;
219 /* leave the other fields as garbage */
220 } else {
221 error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
222 if (error) {
223 /*
224 * The denode does not contain anything useful, so
225 * it would be wrong to leave it on its hash chain.
226 * Arrange for vput() to just forget about it.
227 */
228 ldep->de_Name[0] = SLOT_DELETED;
229
230 vput(nvp);
231 *depp = NULL;
232 return (error);
233 }
234 (void)DE_INTERNALIZE(ldep, direntptr);
235 brelse(bp);
236 }
237
238 /*
239 * Fill in a few fields of the vnode and finish filling in the
240 * denode. Then return the address of the found denode.
241 */
242 if (ldep->de_Attributes & ATTR_DIRECTORY) {
243 /*
244 * Since DOS directory entries that describe directories
245 * have 0 in the filesize field, we take this opportunity
246 * to find out the length of the directory and plug it into
247 * the denode structure.
248 */
249 u_long size;
250
251 /*
252 * XXX it sometimes happens that the "." entry has cluster
253 * number 0 when it shouldn't. Use the actual cluster number
254 * instead of what is written in directory entry.
255 */
256 if (diroffset == 0 && ldep->de_StartCluster != dirclust) {
257 #ifdef MSDOSFS_DEBUG
258 printf("deget(): \".\" entry at clust %lu != %lu\n",
259 dirclust, ldep->de_StartCluster);
260 #endif
261 ldep->de_StartCluster = dirclust;
262 }
263
264 nvp->v_type = VDIR;
265 if (ldep->de_StartCluster != MSDOSFSROOT) {
266 error = pcbmap(ldep, 0xffff, 0, &size, 0);
267 if (error == E2BIG) {
268 ldep->de_FileSize = de_cn2off(pmp, size);
269 error = 0;
270 } else {
271 #ifdef MSDOSFS_DEBUG
272 printf("deget(): pcbmap returned %d\n", error);
273 #endif
274 }
275 }
276 } else
277 nvp->v_type = VREG;
278 ldep->de_modrev = init_va_filerev();
279 *depp = ldep;
280 return (0);
281 }
282
283 int
284 deupdat(struct denode *dep, int waitfor)
285 {
286 struct direntry dir;
287 struct timespec ts;
288 struct buf *bp;
289 struct direntry *dirp;
290 int error;
291
292 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) {
293 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS |
294 DE_MODIFIED);
295 return (0);
296 }
297 getnanotime(&ts);
298 DETIMES(dep, &ts, &ts, &ts);
299 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0)
300 return (0);
301 dep->de_flag &= ~DE_MODIFIED;
302 if (DETOV(dep)->v_vflag & VV_ROOT)
303 return (EINVAL);
304 if (dep->de_refcnt <= 0)
305 return (0);
306 error = readde(dep, &bp, &dirp);
307 if (error)
308 return (error);
309 DE_EXTERNALIZE(&dir, dep);
310 if (bcmp(dirp, &dir, sizeof(dir)) == 0) {
311 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) {
312 brelse(bp);
313 return (0);
314 }
315 } else
316 *dirp = dir;
317 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0)
318 bp->b_flags |= B_CLUSTEROK;
319 if (waitfor)
320 error = bwrite(bp);
321 else if (vm_page_count_severe() || buf_dirty_count_severe())
322 bawrite(bp);
323 else
324 bdwrite(bp);
325 return (error);
326 }
327
328 /*
329 * Truncate the file described by dep to the length specified by length.
330 */
331 int
332 detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred)
333 {
334 int error;
335 int allerror;
336 u_long eofentry;
337 u_long chaintofree;
338 daddr_t bn;
339 int boff;
340 int isadir = dep->de_Attributes & ATTR_DIRECTORY;
341 struct buf *bp;
342 struct msdosfsmount *pmp = dep->de_pmp;
343
344 #ifdef MSDOSFS_DEBUG
345 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
346 #endif
347
348 /*
349 * Disallow attempts to truncate the root directory since it is of
350 * fixed size. That's just the way dos filesystems are. We use
351 * the VROOT bit in the vnode because checking for the directory
352 * bit and a startcluster of 0 in the denode is not adequate to
353 * recognize the root directory at this point in a file or
354 * directory's life.
355 */
356 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
357 #ifdef MSDOSFS_DEBUG
358 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
359 dep->de_dirclust, dep->de_diroffset);
360 #endif
361 return (EINVAL);
362 }
363
364 if (dep->de_FileSize < length) {
365 vnode_pager_setsize(DETOV(dep), length);
366 return deextend(dep, length, cred);
367 }
368
369 /*
370 * If the desired length is 0 then remember the starting cluster of
371 * the file and set the StartCluster field in the directory entry
372 * to 0. If the desired length is not zero, then get the number of
373 * the last cluster in the shortened file. Then get the number of
374 * the first cluster in the part of the file that is to be freed.
375 * Then set the next cluster pointer in the last cluster of the
376 * file to CLUST_EOFE.
377 */
378 if (length == 0) {
379 chaintofree = dep->de_StartCluster;
380 dep->de_StartCluster = 0;
381 eofentry = ~0;
382 } else {
383 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
384 &eofentry, 0);
385 if (error) {
386 #ifdef MSDOSFS_DEBUG
387 printf("detrunc(): pcbmap fails %d\n", error);
388 #endif
389 return (error);
390 }
391 }
392
393 fc_purge(dep, de_clcount(pmp, length));
394
395 /*
396 * If the new length is not a multiple of the cluster size then we
397 * must zero the tail end of the new last cluster in case it
398 * becomes part of the file again because of a seek.
399 */
400 if ((boff = length & pmp->pm_crbomask) != 0) {
401 if (isadir) {
402 bn = cntobn(pmp, eofentry);
403 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
404 NOCRED, &bp);
405 if (error) {
406 brelse(bp);
407 #ifdef MSDOSFS_DEBUG
408 printf("detrunc(): bread fails %d\n", error);
409 #endif
410 return (error);
411 }
412 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
413 if (flags & IO_SYNC)
414 bwrite(bp);
415 else
416 bdwrite(bp);
417 }
418 }
419
420 /*
421 * Write out the updated directory entry. Even if the update fails
422 * we free the trailing clusters.
423 */
424 dep->de_FileSize = length;
425 if (!isadir)
426 dep->de_flag |= DE_UPDATE | DE_MODIFIED;
427 allerror = vtruncbuf(DETOV(dep), cred, length, pmp->pm_bpcluster);
428 #ifdef MSDOSFS_DEBUG
429 if (allerror)
430 printf("detrunc(): vtruncbuf error %d\n", allerror);
431 #endif
432 error = deupdat(dep, !DOINGASYNC((DETOV(dep))));
433 if (error != 0 && allerror == 0)
434 allerror = error;
435 #ifdef MSDOSFS_DEBUG
436 printf("detrunc(): allerror %d, eofentry %lu\n",
437 allerror, eofentry);
438 #endif
439
440 /*
441 * If we need to break the cluster chain for the file then do it
442 * now.
443 */
444 if (eofentry != ~0) {
445 error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
446 &chaintofree, CLUST_EOFE);
447 if (error) {
448 #ifdef MSDOSFS_DEBUG
449 printf("detrunc(): fatentry errors %d\n", error);
450 #endif
451 return (error);
452 }
453 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
454 eofentry);
455 }
456
457 /*
458 * Now free the clusters removed from the file because of the
459 * truncation.
460 */
461 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
462 freeclusterchain(pmp, chaintofree);
463
464 return (allerror);
465 }
466
467 /*
468 * Extend the file described by dep to length specified by length.
469 */
470 int
471 deextend(struct denode *dep, u_long length, struct ucred *cred)
472 {
473 struct msdosfsmount *pmp = dep->de_pmp;
474 u_long count;
475 int error;
476
477 /*
478 * The root of a DOS filesystem cannot be extended.
479 */
480 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
481 return (EINVAL);
482
483 /*
484 * Directories cannot be extended.
485 */
486 if (dep->de_Attributes & ATTR_DIRECTORY)
487 return (EISDIR);
488
489 if (length <= dep->de_FileSize)
490 panic("deextend: file too large");
491
492 /*
493 * Compute the number of clusters to allocate.
494 */
495 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
496 if (count > 0) {
497 if (count > pmp->pm_freeclustercount)
498 return (ENOSPC);
499 error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
500 if (error) {
501 /* truncate the added clusters away again */
502 (void) detrunc(dep, dep->de_FileSize, 0, cred);
503 return (error);
504 }
505 }
506 dep->de_FileSize = length;
507 dep->de_flag |= DE_UPDATE | DE_MODIFIED;
508 return (deupdat(dep, !DOINGASYNC(DETOV(dep))));
509 }
510
511 /*
512 * Move a denode to its correct hash queue after the file it represents has
513 * been moved to a new directory.
514 */
515 void
516 reinsert(struct denode *dep)
517 {
518 struct vnode *vp;
519
520 /*
521 * Fix up the denode cache. If the denode is for a directory,
522 * there is nothing to do since the hash is based on the starting
523 * cluster of the directory file and that hasn't changed. If for a
524 * file the hash is based on the location of the directory entry,
525 * so we must remove it from the cache and re-enter it with the
526 * hash based on the new location of the directory entry.
527 */
528 #if 0
529 if (dep->de_Attributes & ATTR_DIRECTORY)
530 return;
531 #endif
532 vp = DETOV(dep);
533 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust +
534 dep->de_diroffset;
535 vfs_hash_rehash(vp, dep->de_inode);
536 }
537
538 int
539 msdosfs_reclaim(struct vop_reclaim_args *ap)
540 {
541 struct vnode *vp = ap->a_vp;
542 struct denode *dep = VTODE(vp);
543
544 #ifdef MSDOSFS_DEBUG
545 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
546 dep, dep->de_Name, dep->de_refcnt);
547 #endif
548
549 /*
550 * Destroy the vm object and flush associated pages.
551 */
552 vnode_destroy_vobject(vp);
553 /*
554 * Remove the denode from its hash chain.
555 */
556 vfs_hash_remove(vp);
557 /*
558 * Purge old data structures associated with the denode.
559 */
560 #if 0 /* XXX */
561 dep->de_flag = 0;
562 #endif
563 free(dep, M_MSDOSFSNODE);
564 vp->v_data = NULL;
565
566 return (0);
567 }
568
569 int
570 msdosfs_inactive(struct vop_inactive_args *ap)
571 {
572 struct vnode *vp = ap->a_vp;
573 struct denode *dep = VTODE(vp);
574 int error = 0;
575
576 #ifdef MSDOSFS_DEBUG
577 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
578 #endif
579
580 /*
581 * Ignore denodes related to stale file handles.
582 */
583 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
584 goto out;
585
586 /*
587 * If the file has been deleted and it is on a read/write
588 * filesystem, then truncate the file, and mark the directory slot
589 * as empty. (This may not be necessary for the dos filesystem.)
590 */
591 #ifdef MSDOSFS_DEBUG
592 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
593 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
594 #endif
595 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
596 error = detrunc(dep, (u_long) 0, 0, NOCRED);
597 dep->de_flag |= DE_UPDATE;
598 dep->de_Name[0] = SLOT_DELETED;
599 }
600 deupdat(dep, 0);
601
602 out:
603 /*
604 * If we are done with the denode, reclaim it
605 * so that it can be reused immediately.
606 */
607 #ifdef MSDOSFS_DEBUG
608 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n",
609 vrefcnt(vp), dep->de_Name[0]);
610 #endif
611 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
612 vrecycle(vp);
613 return (error);
614 }
Cache object: 89095cb41da0889f9d9b90ccfa321224
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