1 /* $FreeBSD$ */
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(pmp, dirclust, diroffset, depp)
96 struct msdosfsmount *pmp; /* so we know the maj/min number */
97 u_long dirclust; /* cluster this dir entry came from */
98 u_long diroffset; /* index of entry within the cluster */
99 struct denode **depp; /* returns the addr of the gotten denode */
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
146 /*
147 * Do the malloc before the getnewvnode since doing so afterward
148 * might cause a bogus v_data pointer to get dereferenced
149 * elsewhere if malloc should block.
150 */
151 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO);
152
153 /*
154 * Directory entry was not in cache, have to create a vnode and
155 * copy it from the passed disk buffer.
156 */
157 /* getnewvnode() does a VREF() on the vnode */
158 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp);
159 if (error) {
160 *depp = NULL;
161 free(ldep, M_MSDOSFSNODE);
162 return error;
163 }
164 nvp->v_data = ldep;
165 ldep->de_vnode = nvp;
166 ldep->de_flag = 0;
167 ldep->de_dirclust = dirclust;
168 ldep->de_diroffset = diroffset;
169 ldep->de_inode = inode;
170 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL);
171 fc_purge(ldep, 0); /* init the fat cache for this denode */
172 error = insmntque(nvp, mntp);
173 if (error != 0) {
174 free(ldep, M_MSDOSFSNODE);
175 *depp = NULL;
176 return (error);
177 }
178 error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp,
179 de_vncmpf, &inode);
180 if (error) {
181 *depp = NULL;
182 return (error);
183 }
184 if (xvp != NULL) {
185 *depp = xvp->v_data;
186 return (0);
187 }
188
189 ldep->de_pmp = pmp;
190 ldep->de_refcnt = 1;
191 /*
192 * Copy the directory entry into the denode area of the vnode.
193 */
194 if ((dirclust == MSDOSFSROOT
195 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
196 && diroffset == MSDOSFSROOT_OFS) {
197 /*
198 * Directory entry for the root directory. There isn't one,
199 * so we manufacture one. We should probably rummage
200 * through the root directory and find a label entry (if it
201 * exists), and then use the time and date from that entry
202 * as the time and date for the root denode.
203 */
204 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
205
206 ldep->de_Attributes = ATTR_DIRECTORY;
207 ldep->de_LowerCase = 0;
208 if (FAT32(pmp))
209 ldep->de_StartCluster = pmp->pm_rootdirblk;
210 /* de_FileSize will be filled in further down */
211 else {
212 ldep->de_StartCluster = MSDOSFSROOT;
213 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
214 }
215 /*
216 * fill in time and date so that fattime2timespec() doesn't
217 * spit up when called from msdosfs_getattr() with root
218 * denode
219 */
220 ldep->de_CHun = 0;
221 ldep->de_CTime = 0x0000; /* 00:00:00 */
222 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
223 | (1 << DD_DAY_SHIFT);
224 /* Jan 1, 1980 */
225 ldep->de_ADate = ldep->de_CDate;
226 ldep->de_MTime = ldep->de_CTime;
227 ldep->de_MDate = ldep->de_CDate;
228 /* leave the other fields as garbage */
229 } else {
230 error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
231 if (error) {
232 /*
233 * The denode does not contain anything useful, so
234 * it would be wrong to leave it on its hash chain.
235 * Arrange for vput() to just forget about it.
236 */
237 ldep->de_Name[0] = SLOT_DELETED;
238
239 vput(nvp);
240 *depp = NULL;
241 return (error);
242 }
243 (void)DE_INTERNALIZE(ldep, direntptr);
244 brelse(bp);
245 }
246
247 /*
248 * Fill in a few fields of the vnode and finish filling in the
249 * denode. Then return the address of the found denode.
250 */
251 if (ldep->de_Attributes & ATTR_DIRECTORY) {
252 /*
253 * Since DOS directory entries that describe directories
254 * have 0 in the filesize field, we take this opportunity
255 * to find out the length of the directory and plug it into
256 * the denode structure.
257 */
258 u_long size;
259
260 /*
261 * XXX it sometimes happens that the "." entry has cluster
262 * number 0 when it shouldn't. Use the actual cluster number
263 * instead of what is written in directory entry.
264 */
265 if (diroffset == 0 && ldep->de_StartCluster != dirclust) {
266 #ifdef MSDOSFS_DEBUG
267 printf("deget(): \".\" entry at clust %lu != %lu\n",
268 dirclust, ldep->de_StartCluster);
269 #endif
270 ldep->de_StartCluster = dirclust;
271 }
272
273 nvp->v_type = VDIR;
274 if (ldep->de_StartCluster != MSDOSFSROOT) {
275 error = pcbmap(ldep, 0xffff, 0, &size, 0);
276 if (error == E2BIG) {
277 ldep->de_FileSize = de_cn2off(pmp, size);
278 error = 0;
279 } else {
280 #ifdef MSDOSFS_DEBUG
281 printf("deget(): pcbmap returned %d\n", error);
282 #endif
283 }
284 }
285 } else
286 nvp->v_type = VREG;
287 ldep->de_modrev = init_va_filerev();
288 *depp = ldep;
289 return (0);
290 }
291
292 int
293 deupdat(dep, waitfor)
294 struct denode *dep;
295 int waitfor;
296 {
297 struct direntry dir;
298 struct timespec ts;
299 struct buf *bp;
300 struct direntry *dirp;
301 int error;
302
303 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) {
304 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS |
305 DE_MODIFIED);
306 return (0);
307 }
308 getnanotime(&ts);
309 DETIMES(dep, &ts, &ts, &ts);
310 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0)
311 return (0);
312 dep->de_flag &= ~DE_MODIFIED;
313 if (dep->de_Attributes & ATTR_DIRECTORY)
314 return (0);
315 if (dep->de_refcnt <= 0)
316 return (0);
317 error = readde(dep, &bp, &dirp);
318 if (error)
319 return (error);
320 DE_EXTERNALIZE(&dir, dep);
321 if (bcmp(dirp, &dir, sizeof(dir)) == 0) {
322 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) {
323 brelse(bp);
324 return (0);
325 }
326 } else
327 *dirp = dir;
328 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0)
329 bp->b_flags |= B_CLUSTEROK;
330 if (waitfor)
331 error = bwrite(bp);
332 else if (vm_page_count_severe() || buf_dirty_count_severe())
333 bawrite(bp);
334 else
335 bdwrite(bp);
336 return (error);
337 }
338
339 /*
340 * Truncate the file described by dep to the length specified by length.
341 */
342 int
343 detrunc(dep, length, flags, cred, td)
344 struct denode *dep;
345 u_long length;
346 int flags;
347 struct ucred *cred;
348 struct thread *td;
349 {
350 int error;
351 int allerror;
352 u_long eofentry;
353 u_long chaintofree;
354 daddr_t bn;
355 int boff;
356 int isadir = dep->de_Attributes & ATTR_DIRECTORY;
357 struct buf *bp;
358 struct msdosfsmount *pmp = dep->de_pmp;
359
360 #ifdef MSDOSFS_DEBUG
361 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
362 #endif
363
364 /*
365 * Disallow attempts to truncate the root directory since it is of
366 * fixed size. That's just the way dos filesystems are. We use
367 * the VROOT bit in the vnode because checking for the directory
368 * bit and a startcluster of 0 in the denode is not adequate to
369 * recognize the root directory at this point in a file or
370 * directory's life.
371 */
372 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
373 #ifdef MSDOSFS_DEBUG
374 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
375 dep->de_dirclust, dep->de_diroffset);
376 #endif
377 return (EINVAL);
378 }
379
380 if (dep->de_FileSize < length) {
381 vnode_pager_setsize(DETOV(dep), length);
382 return deextend(dep, length, cred);
383 }
384
385 /*
386 * If the desired length is 0 then remember the starting cluster of
387 * the file and set the StartCluster field in the directory entry
388 * to 0. If the desired length is not zero, then get the number of
389 * the last cluster in the shortened file. Then get the number of
390 * the first cluster in the part of the file that is to be freed.
391 * Then set the next cluster pointer in the last cluster of the
392 * file to CLUST_EOFE.
393 */
394 if (length == 0) {
395 chaintofree = dep->de_StartCluster;
396 dep->de_StartCluster = 0;
397 eofentry = ~0;
398 } else {
399 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
400 &eofentry, 0);
401 if (error) {
402 #ifdef MSDOSFS_DEBUG
403 printf("detrunc(): pcbmap fails %d\n", error);
404 #endif
405 return (error);
406 }
407 }
408
409 fc_purge(dep, de_clcount(pmp, length));
410
411 /*
412 * If the new length is not a multiple of the cluster size then we
413 * must zero the tail end of the new last cluster in case it
414 * becomes part of the file again because of a seek.
415 */
416 if ((boff = length & pmp->pm_crbomask) != 0) {
417 if (isadir) {
418 bn = cntobn(pmp, eofentry);
419 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
420 NOCRED, &bp);
421 if (error) {
422 brelse(bp);
423 #ifdef MSDOSFS_DEBUG
424 printf("detrunc(): bread fails %d\n", error);
425 #endif
426 return (error);
427 }
428 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
429 if (flags & IO_SYNC)
430 bwrite(bp);
431 else
432 bdwrite(bp);
433 }
434 }
435
436 /*
437 * Write out the updated directory entry. Even if the update fails
438 * we free the trailing clusters.
439 */
440 dep->de_FileSize = length;
441 if (!isadir)
442 dep->de_flag |= DE_UPDATE | DE_MODIFIED;
443 allerror = vtruncbuf(DETOV(dep), cred, td, length, pmp->pm_bpcluster);
444 #ifdef MSDOSFS_DEBUG
445 if (allerror)
446 printf("detrunc(): vtruncbuf error %d\n", allerror);
447 #endif
448 error = deupdat(dep, !DOINGASYNC((DETOV(dep))));
449 if (error != 0 && allerror == 0)
450 allerror = error;
451 #ifdef MSDOSFS_DEBUG
452 printf("detrunc(): allerror %d, eofentry %lu\n",
453 allerror, eofentry);
454 #endif
455
456 /*
457 * If we need to break the cluster chain for the file then do it
458 * now.
459 */
460 if (eofentry != ~0) {
461 error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
462 &chaintofree, CLUST_EOFE);
463 if (error) {
464 #ifdef MSDOSFS_DEBUG
465 printf("detrunc(): fatentry errors %d\n", error);
466 #endif
467 return (error);
468 }
469 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
470 eofentry);
471 }
472
473 /*
474 * Now free the clusters removed from the file because of the
475 * truncation.
476 */
477 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
478 freeclusterchain(pmp, chaintofree);
479
480 return (allerror);
481 }
482
483 /*
484 * Extend the file described by dep to length specified by length.
485 */
486 int
487 deextend(dep, length, cred)
488 struct denode *dep;
489 u_long length;
490 struct ucred *cred;
491 {
492 struct msdosfsmount *pmp = dep->de_pmp;
493 u_long count;
494 int error;
495
496 /*
497 * The root of a DOS filesystem cannot be extended.
498 */
499 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
500 return (EINVAL);
501
502 /*
503 * Directories cannot be extended.
504 */
505 if (dep->de_Attributes & ATTR_DIRECTORY)
506 return (EISDIR);
507
508 if (length <= dep->de_FileSize)
509 panic("deextend: file too large");
510
511 /*
512 * Compute the number of clusters to allocate.
513 */
514 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
515 if (count > 0) {
516 if (count > pmp->pm_freeclustercount)
517 return (ENOSPC);
518 error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
519 if (error) {
520 /* truncate the added clusters away again */
521 (void) detrunc(dep, dep->de_FileSize, 0, cred, NULL);
522 return (error);
523 }
524 }
525 dep->de_FileSize = length;
526 dep->de_flag |= DE_UPDATE | DE_MODIFIED;
527 return (deupdat(dep, !DOINGASYNC(DETOV(dep))));
528 }
529
530 /*
531 * Move a denode to its correct hash queue after the file it represents has
532 * been moved to a new directory.
533 */
534 void
535 reinsert(dep)
536 struct denode *dep;
537 {
538 struct vnode *vp;
539
540 /*
541 * Fix up the denode cache. If the denode is for a directory,
542 * there is nothing to do since the hash is based on the starting
543 * cluster of the directory file and that hasn't changed. If for a
544 * file the hash is based on the location of the directory entry,
545 * so we must remove it from the cache and re-enter it with the
546 * hash based on the new location of the directory entry.
547 */
548 #if 0
549 if (dep->de_Attributes & ATTR_DIRECTORY)
550 return;
551 #endif
552 vp = DETOV(dep);
553 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust +
554 dep->de_diroffset;
555 vfs_hash_rehash(vp, dep->de_inode);
556 }
557
558 int
559 msdosfs_reclaim(ap)
560 struct vop_reclaim_args /* {
561 struct vnode *a_vp;
562 } */ *ap;
563 {
564 struct vnode *vp = ap->a_vp;
565 struct denode *dep = VTODE(vp);
566
567 #ifdef MSDOSFS_DEBUG
568 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
569 dep, dep->de_Name, dep->de_refcnt);
570 #endif
571
572 /*
573 * Destroy the vm object and flush associated pages.
574 */
575 vnode_destroy_vobject(vp);
576 /*
577 * Remove the denode from its hash chain.
578 */
579 vfs_hash_remove(vp);
580 /*
581 * Purge old data structures associated with the denode.
582 */
583 #if 0 /* XXX */
584 dep->de_flag = 0;
585 #endif
586 free(dep, M_MSDOSFSNODE);
587 vp->v_data = NULL;
588
589 return (0);
590 }
591
592 int
593 msdosfs_inactive(ap)
594 struct vop_inactive_args /* {
595 struct vnode *a_vp;
596 struct thread *a_td;
597 } */ *ap;
598 {
599 struct vnode *vp = ap->a_vp;
600 struct denode *dep = VTODE(vp);
601 struct thread *td = ap->a_td;
602 int error = 0;
603
604 #ifdef MSDOSFS_DEBUG
605 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
606 #endif
607
608 /*
609 * Ignore denodes related to stale file handles.
610 */
611 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
612 goto out;
613
614 /*
615 * If the file has been deleted and it is on a read/write
616 * filesystem, then truncate the file, and mark the directory slot
617 * as empty. (This may not be necessary for the dos filesystem.)
618 */
619 #ifdef MSDOSFS_DEBUG
620 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
621 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
622 #endif
623 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
624 error = detrunc(dep, (u_long) 0, 0, NOCRED, td);
625 dep->de_flag |= DE_UPDATE;
626 dep->de_Name[0] = SLOT_DELETED;
627 }
628 deupdat(dep, 0);
629
630 out:
631 /*
632 * If we are done with the denode, reclaim it
633 * so that it can be reused immediately.
634 */
635 #ifdef MSDOSFS_DEBUG
636 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n",
637 vrefcnt(vp), dep->de_Name[0]);
638 #endif
639 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
640 vrecycle(vp, td);
641 return (error);
642 }
Cache object: 38437278266928d9c570a82be728a689
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