1 /* $FreeBSD: releng/12.0/sys/fs/msdosfs/msdosfs_denode.c 336966 2018-07-31 12:44:28Z emaste $ */
2 /* $NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $ */
3
4 /*-
5 * SPDX-License-Identifier: BSD-4-Clause
6 *
7 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
8 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
9 * All rights reserved.
10 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by TooLs GmbH.
23 * 4. The name of TooLs GmbH may not be used to endorse or promote products
24 * derived from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
32 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
33 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
34 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
35 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37 /*-
38 * Written by Paul Popelka (paulp@uts.amdahl.com)
39 *
40 * You can do anything you want with this software, just don't say you wrote
41 * it, and don't remove this notice.
42 *
43 * This software is provided "as is".
44 *
45 * The author supplies this software to be publicly redistributed on the
46 * understanding that the author is not responsible for the correct
47 * functioning of this software in any circumstances and is not liable for
48 * any damages caused by this software.
49 *
50 * October 1992
51 */
52
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/buf.h>
56 #include <sys/clock.h>
57 #include <sys/kernel.h>
58 #include <sys/malloc.h>
59 #include <sys/mount.h>
60 #include <sys/vmmeter.h>
61 #include <sys/vnode.h>
62
63 #include <vm/vm.h>
64 #include <vm/vm_extern.h>
65
66 #include <fs/msdosfs/bpb.h>
67 #include <fs/msdosfs/direntry.h>
68 #include <fs/msdosfs/denode.h>
69 #include <fs/msdosfs/fat.h>
70 #include <fs/msdosfs/msdosfsmount.h>
71
72 static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part");
73
74 static int
75 de_vncmpf(struct vnode *vp, void *arg)
76 {
77 struct denode *de;
78 uint64_t *a;
79
80 a = arg;
81 de = VTODE(vp);
82 return (de->de_inode != *a);
83 }
84
85 /*
86 * If deget() succeeds it returns with the gotten denode locked().
87 *
88 * pmp - address of msdosfsmount structure of the filesystem containing
89 * the denode of interest. The address of
90 * the msdosfsmount structure are used.
91 * dirclust - which cluster bp contains, if dirclust is 0 (root directory)
92 * diroffset is relative to the beginning of the root directory,
93 * otherwise it is cluster relative.
94 * diroffset - offset past begin of cluster of denode we want
95 * depp - returns the address of the gotten denode.
96 */
97 int
98 deget(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
99 struct denode **depp)
100 {
101 int error;
102 uint64_t inode;
103 struct mount *mntp = pmp->pm_mountp;
104 struct direntry *direntptr;
105 struct denode *ldep;
106 struct vnode *nvp, *xvp;
107 struct buf *bp;
108
109 #ifdef MSDOSFS_DEBUG
110 printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
111 pmp, dirclust, diroffset, depp);
112 #endif
113
114 /*
115 * On FAT32 filesystems, root is a (more or less) normal
116 * directory
117 */
118 if (FAT32(pmp) && dirclust == MSDOSFSROOT)
119 dirclust = pmp->pm_rootdirblk;
120
121 /*
122 * See if the denode is in the denode cache. Use the location of
123 * the directory entry to compute the hash value. For subdir use
124 * address of "." entry. For root dir (if not FAT32) use cluster
125 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
126 *
127 * NOTE: The check for de_refcnt > 0 below insures the denode being
128 * examined does not represent an unlinked but still open file.
129 * These files are not to be accessible even when the directory
130 * entry that represented the file happens to be reused while the
131 * deleted file is still open.
132 */
133 inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset;
134
135 error = vfs_hash_get(mntp, inode, LK_EXCLUSIVE, curthread, &nvp,
136 de_vncmpf, &inode);
137 if (error)
138 return (error);
139 if (nvp != NULL) {
140 *depp = VTODE(nvp);
141 KASSERT((*depp)->de_dirclust == dirclust, ("wrong dirclust"));
142 KASSERT((*depp)->de_diroffset == diroffset, ("wrong diroffset"));
143 return (0);
144 }
145 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO);
146
147 /*
148 * Directory entry was not in cache, have to create a vnode and
149 * copy it from the passed disk buffer.
150 */
151 /* getnewvnode() does a VREF() on the vnode */
152 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp);
153 if (error) {
154 *depp = NULL;
155 free(ldep, M_MSDOSFSNODE);
156 return error;
157 }
158 nvp->v_data = ldep;
159 ldep->de_vnode = nvp;
160 ldep->de_flag = 0;
161 ldep->de_dirclust = dirclust;
162 ldep->de_diroffset = diroffset;
163 ldep->de_inode = inode;
164 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL);
165 fc_purge(ldep, 0); /* init the FAT cache for this denode */
166 error = insmntque(nvp, mntp);
167 if (error != 0) {
168 free(ldep, M_MSDOSFSNODE);
169 *depp = NULL;
170 return (error);
171 }
172 error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp,
173 de_vncmpf, &inode);
174 if (error) {
175 *depp = NULL;
176 return (error);
177 }
178 if (xvp != NULL) {
179 *depp = xvp->v_data;
180 return (0);
181 }
182
183 ldep->de_pmp = pmp;
184 ldep->de_refcnt = 1;
185 /*
186 * Copy the directory entry into the denode area of the vnode.
187 */
188 if ((dirclust == MSDOSFSROOT
189 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
190 && diroffset == MSDOSFSROOT_OFS) {
191 /*
192 * Directory entry for the root directory. There isn't one,
193 * so we manufacture one. We should probably rummage
194 * through the root directory and find a label entry (if it
195 * exists), and then use the time and date from that entry
196 * as the time and date for the root denode.
197 */
198 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
199
200 ldep->de_Attributes = ATTR_DIRECTORY;
201 ldep->de_LowerCase = 0;
202 if (FAT32(pmp))
203 ldep->de_StartCluster = pmp->pm_rootdirblk;
204 /* de_FileSize will be filled in further down */
205 else {
206 ldep->de_StartCluster = MSDOSFSROOT;
207 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
208 }
209 /*
210 * fill in time and date so that fattime2timespec() doesn't
211 * spit up when called from msdosfs_getattr() with root
212 * denode
213 */
214 ldep->de_CHun = 0;
215 ldep->de_CTime = 0x0000; /* 00:00:00 */
216 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
217 | (1 << DD_DAY_SHIFT);
218 /* Jan 1, 1980 */
219 ldep->de_ADate = ldep->de_CDate;
220 ldep->de_MTime = ldep->de_CTime;
221 ldep->de_MDate = ldep->de_CDate;
222 /* leave the other fields as garbage */
223 } else {
224 error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
225 if (error) {
226 /*
227 * The denode does not contain anything useful, so
228 * it would be wrong to leave it on its hash chain.
229 * Arrange for vput() to just forget about it.
230 */
231 ldep->de_Name[0] = SLOT_DELETED;
232
233 vput(nvp);
234 *depp = NULL;
235 return (error);
236 }
237 (void)DE_INTERNALIZE(ldep, direntptr);
238 brelse(bp);
239 }
240
241 /*
242 * Fill in a few fields of the vnode and finish filling in the
243 * denode. Then return the address of the found denode.
244 */
245 if (ldep->de_Attributes & ATTR_DIRECTORY) {
246 /*
247 * Since DOS directory entries that describe directories
248 * have 0 in the filesize field, we take this opportunity
249 * to find out the length of the directory and plug it into
250 * the denode structure.
251 */
252 u_long size;
253
254 /*
255 * XXX it sometimes happens that the "." entry has cluster
256 * number 0 when it shouldn't. Use the actual cluster number
257 * instead of what is written in directory entry.
258 */
259 if (diroffset == 0 && ldep->de_StartCluster != dirclust) {
260 #ifdef MSDOSFS_DEBUG
261 printf("deget(): \".\" entry at clust %lu != %lu\n",
262 dirclust, ldep->de_StartCluster);
263 #endif
264 ldep->de_StartCluster = dirclust;
265 }
266
267 nvp->v_type = VDIR;
268 if (ldep->de_StartCluster != MSDOSFSROOT) {
269 error = pcbmap(ldep, 0xffff, 0, &size, 0);
270 if (error == E2BIG) {
271 ldep->de_FileSize = de_cn2off(pmp, size);
272 error = 0;
273 } else {
274 #ifdef MSDOSFS_DEBUG
275 printf("deget(): pcbmap returned %d\n", error);
276 #endif
277 }
278 }
279 } else
280 nvp->v_type = VREG;
281 ldep->de_modrev = init_va_filerev();
282 *depp = ldep;
283 return (0);
284 }
285
286 int
287 deupdat(struct denode *dep, int waitfor)
288 {
289 struct direntry dir;
290 struct timespec ts;
291 struct buf *bp;
292 struct direntry *dirp;
293 int error;
294
295 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) {
296 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS |
297 DE_MODIFIED);
298 return (0);
299 }
300 vfs_timestamp(&ts);
301 DETIMES(dep, &ts, &ts, &ts);
302 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0)
303 return (0);
304 dep->de_flag &= ~DE_MODIFIED;
305 if (DETOV(dep)->v_vflag & VV_ROOT)
306 return (EINVAL);
307 if (dep->de_refcnt <= 0)
308 return (0);
309 error = readde(dep, &bp, &dirp);
310 if (error)
311 return (error);
312 DE_EXTERNALIZE(&dir, dep);
313 if (bcmp(dirp, &dir, sizeof(dir)) == 0) {
314 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) {
315 brelse(bp);
316 return (0);
317 }
318 } else
319 *dirp = dir;
320 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0)
321 bp->b_flags |= B_CLUSTEROK;
322 if (waitfor)
323 error = bwrite(bp);
324 else if (vm_page_count_severe() || buf_dirty_count_severe())
325 bawrite(bp);
326 else
327 bdwrite(bp);
328 return (error);
329 }
330
331 /*
332 * Truncate the file described by dep to the length specified by length.
333 */
334 int
335 detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred)
336 {
337 int error;
338 int allerror;
339 u_long eofentry;
340 u_long chaintofree;
341 daddr_t bn;
342 int boff;
343 int isadir = dep->de_Attributes & ATTR_DIRECTORY;
344 struct buf *bp;
345 struct msdosfsmount *pmp = dep->de_pmp;
346
347 #ifdef MSDOSFS_DEBUG
348 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
349 #endif
350
351 /*
352 * Disallow attempts to truncate the root directory since it is of
353 * fixed size. That's just the way dos filesystems are. We use
354 * the VROOT bit in the vnode because checking for the directory
355 * bit and a startcluster of 0 in the denode is not adequate to
356 * recognize the root directory at this point in a file or
357 * directory's life.
358 */
359 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
360 #ifdef MSDOSFS_DEBUG
361 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
362 dep->de_dirclust, dep->de_diroffset);
363 #endif
364 return (EINVAL);
365 }
366
367 if (dep->de_FileSize < length) {
368 vnode_pager_setsize(DETOV(dep), length);
369 return deextend(dep, length, cred);
370 }
371
372 /*
373 * If the desired length is 0 then remember the starting cluster of
374 * the file and set the StartCluster field in the directory entry
375 * to 0. If the desired length is not zero, then get the number of
376 * the last cluster in the shortened file. Then get the number of
377 * the first cluster in the part of the file that is to be freed.
378 * Then set the next cluster pointer in the last cluster of the
379 * file to CLUST_EOFE.
380 */
381 if (length == 0) {
382 chaintofree = dep->de_StartCluster;
383 dep->de_StartCluster = 0;
384 eofentry = ~0;
385 } else {
386 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
387 &eofentry, 0);
388 if (error) {
389 #ifdef MSDOSFS_DEBUG
390 printf("detrunc(): pcbmap fails %d\n", error);
391 #endif
392 return (error);
393 }
394 }
395
396 fc_purge(dep, de_clcount(pmp, length));
397
398 /*
399 * If the new length is not a multiple of the cluster size then we
400 * must zero the tail end of the new last cluster in case it
401 * becomes part of the file again because of a seek.
402 */
403 if ((boff = length & pmp->pm_crbomask) != 0) {
404 if (isadir) {
405 bn = cntobn(pmp, eofentry);
406 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
407 NOCRED, &bp);
408 if (error) {
409 brelse(bp);
410 #ifdef MSDOSFS_DEBUG
411 printf("detrunc(): bread fails %d\n", error);
412 #endif
413 return (error);
414 }
415 memset(bp->b_data + boff, 0, pmp->pm_bpcluster - boff);
416 if (flags & IO_SYNC)
417 bwrite(bp);
418 else
419 bdwrite(bp);
420 }
421 }
422
423 /*
424 * Write out the updated directory entry. Even if the update fails
425 * we free the trailing clusters.
426 */
427 dep->de_FileSize = length;
428 if (!isadir)
429 dep->de_flag |= DE_UPDATE | DE_MODIFIED;
430 allerror = vtruncbuf(DETOV(dep), cred, length, pmp->pm_bpcluster);
431 #ifdef MSDOSFS_DEBUG
432 if (allerror)
433 printf("detrunc(): vtruncbuf error %d\n", allerror);
434 #endif
435 error = deupdat(dep, !DOINGASYNC((DETOV(dep))));
436 if (error != 0 && allerror == 0)
437 allerror = error;
438 #ifdef MSDOSFS_DEBUG
439 printf("detrunc(): allerror %d, eofentry %lu\n",
440 allerror, eofentry);
441 #endif
442
443 /*
444 * If we need to break the cluster chain for the file then do it
445 * now.
446 */
447 if (eofentry != ~0) {
448 error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
449 &chaintofree, CLUST_EOFE);
450 if (error) {
451 #ifdef MSDOSFS_DEBUG
452 printf("detrunc(): fatentry errors %d\n", error);
453 #endif
454 return (error);
455 }
456 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
457 eofentry);
458 }
459
460 /*
461 * Now free the clusters removed from the file because of the
462 * truncation.
463 */
464 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
465 freeclusterchain(pmp, chaintofree);
466
467 return (allerror);
468 }
469
470 /*
471 * Extend the file described by dep to length specified by length.
472 */
473 int
474 deextend(struct denode *dep, u_long length, struct ucred *cred)
475 {
476 struct msdosfsmount *pmp = dep->de_pmp;
477 u_long count;
478 int error;
479
480 /*
481 * The root of a DOS filesystem cannot be extended.
482 */
483 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
484 return (EINVAL);
485
486 /*
487 * Directories cannot be extended.
488 */
489 if (dep->de_Attributes & ATTR_DIRECTORY)
490 return (EISDIR);
491
492 if (length <= dep->de_FileSize)
493 panic("deextend: file too large");
494
495 /*
496 * Compute the number of clusters to allocate.
497 */
498 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
499 if (count > 0) {
500 if (count > pmp->pm_freeclustercount)
501 return (ENOSPC);
502 error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
503 if (error) {
504 /* truncate the added clusters away again */
505 (void) detrunc(dep, dep->de_FileSize, 0, cred);
506 return (error);
507 }
508 }
509 dep->de_FileSize = length;
510 dep->de_flag |= DE_UPDATE | DE_MODIFIED;
511 return (deupdat(dep, !DOINGASYNC(DETOV(dep))));
512 }
513
514 /*
515 * Move a denode to its correct hash queue after the file it represents has
516 * been moved to a new directory.
517 */
518 void
519 reinsert(struct denode *dep)
520 {
521 struct vnode *vp;
522
523 /*
524 * Fix up the denode cache. If the denode is for a directory,
525 * there is nothing to do since the hash is based on the starting
526 * cluster of the directory file and that hasn't changed. If for a
527 * file the hash is based on the location of the directory entry,
528 * so we must remove it from the cache and re-enter it with the
529 * hash based on the new location of the directory entry.
530 */
531 #if 0
532 if (dep->de_Attributes & ATTR_DIRECTORY)
533 return;
534 #endif
535 vp = DETOV(dep);
536 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust +
537 dep->de_diroffset;
538 vfs_hash_rehash(vp, dep->de_inode);
539 }
540
541 int
542 msdosfs_reclaim(struct vop_reclaim_args *ap)
543 {
544 struct vnode *vp = ap->a_vp;
545 struct denode *dep = VTODE(vp);
546
547 #ifdef MSDOSFS_DEBUG
548 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
549 dep, dep->de_Name, dep->de_refcnt);
550 #endif
551
552 /*
553 * Destroy the vm object and flush associated pages.
554 */
555 vnode_destroy_vobject(vp);
556 /*
557 * Remove the denode from its hash chain.
558 */
559 vfs_hash_remove(vp);
560 /*
561 * Purge old data structures associated with the denode.
562 */
563 #if 0 /* XXX */
564 dep->de_flag = 0;
565 #endif
566 free(dep, M_MSDOSFSNODE);
567 vp->v_data = NULL;
568
569 return (0);
570 }
571
572 int
573 msdosfs_inactive(struct vop_inactive_args *ap)
574 {
575 struct vnode *vp = ap->a_vp;
576 struct denode *dep = VTODE(vp);
577 int error = 0;
578
579 #ifdef MSDOSFS_DEBUG
580 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
581 #endif
582
583 /*
584 * Ignore denodes related to stale file handles.
585 */
586 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
587 goto out;
588
589 /*
590 * If the file has been deleted and it is on a read/write
591 * filesystem, then truncate the file, and mark the directory slot
592 * as empty. (This may not be necessary for the dos filesystem.)
593 */
594 #ifdef MSDOSFS_DEBUG
595 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %llx, MNT_RDONLY %llx\n",
596 dep, dep->de_refcnt, (unsigned long long)vp->v_mount->mnt_flag,
597 (unsigned long long)MNT_RDONLY);
598 #endif
599 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
600 error = detrunc(dep, (u_long) 0, 0, NOCRED);
601 dep->de_flag |= DE_UPDATE;
602 dep->de_Name[0] = SLOT_DELETED;
603 }
604 deupdat(dep, 0);
605
606 out:
607 /*
608 * If we are done with the denode, reclaim it
609 * so that it can be reused immediately.
610 */
611 #ifdef MSDOSFS_DEBUG
612 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n",
613 vrefcnt(vp), dep->de_Name[0]);
614 #endif
615 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
616 vrecycle(vp);
617 return (error);
618 }
Cache object: f2b40296f2802c1530c37e72668c99b5
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