1 /* $FreeBSD: src/sys/msdosfs/msdosfs_denode.c,v 1.47.2.3 2002/08/22 16:20:15 trhodes Exp $ */
2 /* $DragonFly: src/sys/vfs/msdosfs/msdosfs_denode.c,v 1.18 2004/10/27 08:57:48 dillon Exp $ */
3 /* $NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $ */
6 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
7 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
9 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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.
37 * Written by Paul Popelka (paulp@uts.amdahl.com)
39 * You can do anything you want with this software, just don't say you wrote
40 * it, and don't remove this notice.
42 * This software is provided "as is".
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.
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/kernel.h>
55 #include <sys/mount.h>
56 #include <sys/malloc.h>
59 #include <sys/vnode.h>
62 #include <vm/vm_extern.h>
65 #include "msdosfsmount.h"
70 static int msdosfs_hashins (struct denode *dep);
71 static void msdosfs_hashrem (struct denode *dep);
73 static MALLOC_DEFINE(M_MSDOSFSNODE, "MSDOSFS node", "MSDOSFS vnode private part");
75 static struct denode **dehashtbl;
76 static u_long dehash; /* size of hash table - 1 */
77 #define DEHASH(dev, dcl, doff) (dehashtbl[(minor(dev) + (dcl) + (doff) / \
78 sizeof(struct direntry)) & dehash])
79 static struct lwkt_token dehash_token;
85 #define SETHIGH(q, h) { \
88 tmp.val[_QUAD_HIGHWORD] = (h); \
91 #define SETLOW(q, l) { \
94 tmp.val[_QUAD_LOWWORD] = (l); \
98 static struct denode *
99 msdosfs_hashget (dev_t dev, u_long dirclust, u_long diroff);
103 msdosfs_init(struct vfsconf *vfsp)
106 while (dehash < desiredvnodes)
108 dehashtbl = malloc(sizeof(void *) * dehash, M_MSDOSFSMNT,
111 lwkt_token_init(&dehash_token);
116 msdosfs_uninit(struct vfsconf *vfsp)
120 free(dehashtbl, M_MSDOSFSMNT);
124 static struct denode *
125 msdosfs_hashget(dev_t dev, u_long dirclust, u_long diroff)
127 struct thread *td = curthread; /* XXX */
132 lwkt_gettoken(&ilock, &dehash_token);
134 for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
135 if (dirclust != dep->de_dirclust
136 || diroff != dep->de_diroffset
137 || dev != dep->de_dev
138 || dep->de_refcnt == 0) {
142 if (vget(vp, LK_EXCLUSIVE, td))
146 * We must check to see if the inode has been ripped
147 * out from under us after blocking.
149 for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
150 if (dirclust == dep->de_dirclust
151 && diroff == dep->de_diroffset
152 && dev == dep->de_dev
153 && dep->de_refcnt != 0) {
157 if (dep == NULL || DETOV(dep) != vp) {
161 lwkt_reltoken(&ilock);
164 lwkt_reltoken(&ilock);
170 msdosfs_hashins(struct denode *dep)
172 struct denode **depp, *deq;
175 lwkt_gettoken(&ilock, &dehash_token);
176 depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
177 while ((deq = *depp) != NULL) {
178 if (deq->de_dev == dep->de_dev &&
179 deq->de_dirclust == dep->de_dirclust &&
180 deq->de_diroffset == dep->de_diroffset) {
181 lwkt_reltoken(&ilock);
184 depp = &deq->de_next;
188 lwkt_reltoken(&ilock);
194 msdosfs_hashrem(struct denode *dep)
196 struct denode **depp, *deq;
199 lwkt_gettoken(&ilock, &dehash_token);
200 depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
201 while ((deq = *depp) != NULL) {
204 depp = &deq->de_next;
206 KKASSERT(dep == deq);
207 *depp = dep->de_next;
209 lwkt_reltoken(&ilock);
213 msdosfs_reinsert(struct denode *ip, u_long new_dirclust, u_long new_diroffset)
217 lwkt_gettoken(&ilock, &dehash_token);
219 ip->de_dirclust = new_dirclust;
220 ip->de_diroffset = new_diroffset;
222 lwkt_reltoken(&ilock);
226 * If deget() succeeds it returns with the gotten denode locked().
228 * pmp - address of msdosfsmount structure of the filesystem containing
229 * the denode of interest. The pm_dev field and the address of
230 * the msdosfsmount structure are used.
231 * dirclust - which cluster bp contains, if dirclust is 0 (root directory)
232 * diroffset is relative to the beginning of the root directory,
233 * otherwise it is cluster relative.
234 * diroffset - offset past begin of cluster of denode we want
235 * depp - returns the address of the gotten denode.
238 deget(struct msdosfsmount *pmp, /* so we know the maj/min number */
239 u_long dirclust, /* cluster this dir entry came from */
240 u_long diroffset, /* index of entry within the cluster */
241 struct denode **depp) /* returns the addr of the gotten denode */
244 dev_t dev = pmp->pm_dev;
245 struct mount *mntp = pmp->pm_mountp;
246 struct direntry *direntptr;
253 printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
254 pmp, dirclust, diroffset, depp);
258 * On FAT32 filesystems, root is a (more or less) normal
261 if (FAT32(pmp) && dirclust == MSDOSFSROOT)
262 dirclust = pmp->pm_rootdirblk;
266 * See if the denode is in the denode cache. Use the location of
267 * the directory entry to compute the hash value. For subdir use
268 * address of "." entry. For root dir (if not FAT32) use cluster
269 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
271 * NOTE: The check for de_refcnt > 0 below insures the denode being
272 * examined does not represent an unlinked but still open file.
273 * These files are not to be accessible even when the directory
274 * entry that represented the file happens to be reused while the
275 * deleted file is still open.
277 ldep = msdosfs_hashget(dev, dirclust, diroffset);
284 * Do the MALLOC before the getnewvnode since doing so afterward
285 * might cause a bogus v_data pointer to get dereferenced
286 * elsewhere if MALLOC should block.
288 MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK);
291 * Directory entry was not in cache, have to create a vnode and
292 * copy it from the passed disk buffer.
295 /* getnewvnode() does a vref() on the vnode */
296 error = getnewvnode(VT_MSDOSFS, mntp, mntp->mnt_vn_ops, &nvp,
300 FREE(ldep, M_MSDOSFSNODE);
304 bzero((caddr_t)ldep, sizeof *ldep);
305 ldep->de_vnode = nvp;
309 ldep->de_dirclust = dirclust;
310 ldep->de_diroffset = diroffset;
311 fc_purge(ldep, 0); /* init the fat cache for this denode */
314 * Insert the denode into the hash queue. If a collision occurs
315 * throw away the vnode and try again.
317 if (msdosfs_hashins(ldep) != 0) {
318 printf("debug: msdosfs: hashins collision, retrying\n");
320 free(ldep, M_MSDOSFSNODE);
327 * Copy the directory entry into the denode area of the vnode.
329 if ((dirclust == MSDOSFSROOT
330 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
331 && diroffset == MSDOSFSROOT_OFS) {
333 * Directory entry for the root directory. There isn't one,
334 * so we manufacture one. We should probably rummage
335 * through the root directory and find a label entry (if it
336 * exists), and then use the time and date from that entry
337 * as the time and date for the root denode.
339 nvp->v_flag |= VROOT; /* should be further down XXX */
341 ldep->de_Attributes = ATTR_DIRECTORY;
342 ldep->de_LowerCase = 0;
344 ldep->de_StartCluster = pmp->pm_rootdirblk;
345 /* de_FileSize will be filled in further down */
347 ldep->de_StartCluster = MSDOSFSROOT;
348 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
351 * fill in time and date so that dos2unixtime() doesn't
352 * spit up when called from msdosfs_getattr() with root
356 ldep->de_CTime = 0x0000; /* 00:00:00 */
357 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
358 | (1 << DD_DAY_SHIFT);
360 ldep->de_ADate = ldep->de_CDate;
361 ldep->de_MTime = ldep->de_CTime;
362 ldep->de_MDate = ldep->de_CDate;
363 /* leave the other fields as garbage */
365 error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
368 * The denode does not contain anything useful, so
369 * it would be wrong to leave it on its hash chain.
370 * Arrange for vput() to just forget about it.
372 ldep->de_Name[0] = SLOT_DELETED;
378 DE_INTERNALIZE(ldep, direntptr);
383 * Fill in a few fields of the vnode and finish filling in the
384 * denode. Then return the address of the found denode.
386 if (ldep->de_Attributes & ATTR_DIRECTORY) {
388 * Since DOS directory entries that describe directories
389 * have 0 in the filesize field, we take this opportunity
390 * to find out the length of the directory and plug it into
391 * the denode structure.
396 * XXX Sometimes, these arrives that . entry have cluster
397 * number 0, when it shouldn't. Use real cluster number
398 * instead of what is written in directory entry.
400 if ((diroffset == 0) && (ldep->de_StartCluster != dirclust)) {
401 printf("deget(): . entry at clust %ld != %ld\n",
402 dirclust, ldep->de_StartCluster);
403 ldep->de_StartCluster = dirclust;
407 if (ldep->de_StartCluster != MSDOSFSROOT) {
408 error = pcbmap(ldep, 0xffff, 0, &size, 0);
409 if (error == E2BIG) {
410 ldep->de_FileSize = de_cn2off(pmp, size);
413 printf("deget(): pcbmap returned %d\n", error);
419 SETHIGH(ldep->de_modrev, tv.tv_sec);
420 SETLOW(ldep->de_modrev, tv.tv_usec * 4294);
421 ldep->de_devvp = pmp->pm_devvp;
422 vref(ldep->de_devvp);
424 * Leave nvp locked and refd so the returned inode is effectively
432 deupdat(struct denode *dep, int waitfor)
436 struct direntry *dirp;
439 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
442 DETIMES(dep, &ts, &ts, &ts);
443 if ((dep->de_flag & DE_MODIFIED) == 0)
445 dep->de_flag &= ~DE_MODIFIED;
446 if (dep->de_Attributes & ATTR_DIRECTORY)
448 if (dep->de_refcnt <= 0)
450 error = readde(dep, &bp, &dirp);
453 DE_EXTERNALIZE(dirp, dep);
463 * Truncate the file described by dep to the length specified by length.
466 detrunc(struct denode *dep, u_long length, int flags, struct thread *td)
474 int isadir = dep->de_Attributes & ATTR_DIRECTORY;
476 struct msdosfsmount *pmp = dep->de_pmp;
479 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
483 * Disallow attempts to truncate the root directory since it is of
484 * fixed size. That's just the way dos filesystems are. We use
485 * the VROOT bit in the vnode because checking for the directory
486 * bit and a startcluster of 0 in the denode is not adequate to
487 * recognize the root directory at this point in a file or
490 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
491 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
492 dep->de_dirclust, dep->de_diroffset);
497 if (dep->de_FileSize < length) {
498 vnode_pager_setsize(DETOV(dep), length);
499 return deextend(dep, length);
503 * If the desired length is 0 then remember the starting cluster of
504 * the file and set the StartCluster field in the directory entry
505 * to 0. If the desired length is not zero, then get the number of
506 * the last cluster in the shortened file. Then get the number of
507 * the first cluster in the part of the file that is to be freed.
508 * Then set the next cluster pointer in the last cluster of the
509 * file to CLUST_EOFE.
512 chaintofree = dep->de_StartCluster;
513 dep->de_StartCluster = 0;
516 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
520 printf("detrunc(): pcbmap fails %d\n", error);
526 fc_purge(dep, de_clcount(pmp, length));
529 * If the new length is not a multiple of the cluster size then we
530 * must zero the tail end of the new last cluster in case it
531 * becomes part of the file again because of a seek.
533 if ((boff = length & pmp->pm_crbomask) != 0) {
535 bn = cntobn(pmp, eofentry);
536 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, &bp);
538 bn = de_blk(pmp, length);
539 error = bread(DETOV(dep), bn, pmp->pm_bpcluster, &bp);
544 printf("detrunc(): bread fails %d\n", error);
549 * is this the right place for it?
551 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
559 * Write out the updated directory entry. Even if the update fails
560 * we free the trailing clusters.
562 dep->de_FileSize = length;
564 dep->de_flag |= DE_UPDATE|DE_MODIFIED;
565 allerror = vtruncbuf(DETOV(dep), td, length, pmp->pm_bpcluster);
568 printf("detrunc(): vtruncbuf error %d\n", allerror);
570 error = deupdat(dep, 1);
571 if (error && (allerror == 0))
574 printf("detrunc(): allerror %d, eofentry %lu\n",
579 * If we need to break the cluster chain for the file then do it
582 if (eofentry != ~0) {
583 error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
584 &chaintofree, CLUST_EOFE);
587 printf("detrunc(): fatentry errors %d\n", error);
591 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
596 * Now free the clusters removed from the file because of the
599 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
600 freeclusterchain(pmp, chaintofree);
606 * Extend the file described by dep to length specified by length.
609 deextend(struct denode *dep, u_long length)
611 struct msdosfsmount *pmp = dep->de_pmp;
616 * The root of a DOS filesystem cannot be extended.
618 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
622 * Directories cannot be extended.
624 if (dep->de_Attributes & ATTR_DIRECTORY)
627 if (length <= dep->de_FileSize)
628 panic("deextend: file too large");
631 * Compute the number of clusters to allocate.
633 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
635 if (count > pmp->pm_freeclustercount)
637 error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
639 /* truncate the added clusters away again */
640 (void) detrunc(dep, dep->de_FileSize, 0, NULL);
644 dep->de_FileSize = length;
645 dep->de_flag |= DE_UPDATE|DE_MODIFIED;
646 return (deupdat(dep, 1));
650 * msdosfs_reclaim(struct vnode *a_vp)
653 msdosfs_reclaim(struct vop_reclaim_args *ap)
655 struct vnode *vp = ap->a_vp;
656 struct denode *dep = VTODE(vp);
659 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
660 dep, dep ? dep->de_Name : "?", dep ? dep->de_refcnt : -1);
663 if (prtactive && vp->v_usecount != 0)
664 vprint("msdosfs_reclaim(): pushing active", vp);
666 * Remove the denode from its hash chain.
670 msdosfs_hashrem(dep);
672 vrele(dep->de_devvp);
675 free(dep, M_MSDOSFSNODE);
681 * msdosfs_inactive(struct vnode *a_vp, struct thread *a_td)
684 msdosfs_inactive(struct vop_inactive_args *ap)
686 struct vnode *vp = ap->a_vp;
687 struct denode *dep = VTODE(vp);
691 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
694 if (prtactive && vp->v_usecount != 0)
695 vprint("msdosfs_inactive(): pushing active", vp);
698 * Ignore denodes related to stale file handles.
700 if (dep->de_Name[0] == SLOT_DELETED)
704 * If the file has been deleted and it is on a read/write
705 * filesystem, then truncate the file, and mark the directory slot
706 * as empty. (This may not be necessary for the dos filesystem.)
709 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
710 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
712 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
713 error = detrunc(dep, (u_long) 0, 0, ap->a_td);
714 dep->de_flag |= DE_UPDATE;
715 dep->de_Name[0] = SLOT_DELETED;
721 * If we are done with the denode, reclaim it
722 * so that it can be reused immediately.
725 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", vp->v_usecount,
728 if (dep->de_Name[0] == SLOT_DELETED)
729 vrecycle(vp, ap->a_td);