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 1.27 2006/12/23 00:41:29 swildner 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 (cdev_t dev, u_long dirclust, u_long diroff);
103 msdosfs_init(struct vfsconf *vfsp)
106 while (dehash < desiredvnodes)
108 dehashtbl = kmalloc(sizeof(void *) * dehash, M_MSDOSFSMNT,
111 lwkt_token_init(&dehash_token);
116 msdosfs_uninit(struct vfsconf *vfsp)
120 kfree(dehashtbl, M_MSDOSFSMNT);
124 static struct denode *
125 msdosfs_hashget(cdev_t dev, u_long dirclust, u_long diroff)
131 lwkt_gettoken(&ilock, &dehash_token);
133 for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
134 if (dirclust != dep->de_dirclust
135 || diroff != dep->de_diroffset
136 || dev != dep->de_dev
137 || dep->de_refcnt == 0) {
141 if (vget(vp, LK_EXCLUSIVE))
145 * We must check to see if the inode has been ripped
146 * out from under us after blocking.
148 for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
149 if (dirclust == dep->de_dirclust
150 && diroff == dep->de_diroffset
151 && dev == dep->de_dev
152 && dep->de_refcnt != 0) {
156 if (dep == NULL || DETOV(dep) != vp) {
160 lwkt_reltoken(&ilock);
163 lwkt_reltoken(&ilock);
169 msdosfs_hashins(struct denode *dep)
171 struct denode **depp, *deq;
174 lwkt_gettoken(&ilock, &dehash_token);
175 depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
176 while ((deq = *depp) != NULL) {
177 if (deq->de_dev == dep->de_dev &&
178 deq->de_dirclust == dep->de_dirclust &&
179 deq->de_diroffset == dep->de_diroffset) {
180 lwkt_reltoken(&ilock);
183 depp = &deq->de_next;
187 lwkt_reltoken(&ilock);
193 msdosfs_hashrem(struct denode *dep)
195 struct denode **depp, *deq;
198 lwkt_gettoken(&ilock, &dehash_token);
199 depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
200 while ((deq = *depp) != NULL) {
203 depp = &deq->de_next;
205 KKASSERT(dep == deq);
206 *depp = dep->de_next;
208 lwkt_reltoken(&ilock);
212 msdosfs_reinsert(struct denode *ip, u_long new_dirclust, u_long new_diroffset)
216 lwkt_gettoken(&ilock, &dehash_token);
218 ip->de_dirclust = new_dirclust;
219 ip->de_diroffset = new_diroffset;
221 lwkt_reltoken(&ilock);
225 * If deget() succeeds it returns with the gotten denode locked().
227 * pmp - address of msdosfsmount structure of the filesystem containing
228 * the denode of interest. The pm_dev field and the address of
229 * the msdosfsmount structure are used.
230 * dirclust - which cluster bp contains, if dirclust is 0 (root directory)
231 * diroffset is relative to the beginning of the root directory,
232 * otherwise it is cluster relative.
233 * diroffset - offset past begin of cluster of denode we want
234 * depp - returns the address of the gotten denode.
237 deget(struct msdosfsmount *pmp, /* so we know the maj/min number */
238 u_long dirclust, /* cluster this dir entry came from */
239 u_long diroffset, /* index of entry within the cluster */
240 struct denode **depp) /* returns the addr of the gotten denode */
243 cdev_t dev = pmp->pm_dev;
244 struct mount *mntp = pmp->pm_mountp;
245 struct direntry *direntptr;
252 kprintf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
253 pmp, dirclust, diroffset, depp);
257 * On FAT32 filesystems, root is a (more or less) normal
260 if (FAT32(pmp) && dirclust == MSDOSFSROOT)
261 dirclust = pmp->pm_rootdirblk;
265 * See if the denode is in the denode cache. Use the location of
266 * the directory entry to compute the hash value. For subdir use
267 * address of "." entry. For root dir (if not FAT32) use cluster
268 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
270 * NOTE: The check for de_refcnt > 0 below insures the denode being
271 * examined does not represent an unlinked but still open file.
272 * These files are not to be accessible even when the directory
273 * entry that represented the file happens to be reused while the
274 * deleted file is still open.
276 ldep = msdosfs_hashget(dev, dirclust, diroffset);
283 * Do the MALLOC before the getnewvnode since doing so afterward
284 * might cause a bogus v_data pointer to get dereferenced
285 * elsewhere if MALLOC should block.
287 MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK);
290 * Directory entry was not in cache, have to create a vnode and
291 * copy it from the passed disk buffer.
294 /* getnewvnode() does a vref() on the vnode */
295 error = getnewvnode(VT_MSDOSFS, mntp, &nvp, VLKTIMEOUT, 0);
298 FREE(ldep, M_MSDOSFSNODE);
302 bzero((caddr_t)ldep, sizeof *ldep);
303 ldep->de_vnode = nvp;
307 ldep->de_dirclust = dirclust;
308 ldep->de_diroffset = diroffset;
309 fc_purge(ldep, 0); /* init the fat cache for this denode */
312 * Insert the denode into the hash queue. If a collision occurs
313 * throw away the vnode and try again.
315 if (msdosfs_hashins(ldep) != 0) {
316 kprintf("debug: msdosfs: hashins collision, retrying\n");
318 kfree(ldep, M_MSDOSFSNODE);
325 * Copy the directory entry into the denode area of the vnode.
327 if ((dirclust == MSDOSFSROOT
328 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
329 && diroffset == MSDOSFSROOT_OFS) {
331 * Directory entry for the root directory. There isn't one,
332 * so we manufacture one. We should probably rummage
333 * through the root directory and find a label entry (if it
334 * exists), and then use the time and date from that entry
335 * as the time and date for the root denode.
337 nvp->v_flag |= VROOT; /* should be further down XXX */
339 ldep->de_Attributes = ATTR_DIRECTORY;
340 ldep->de_LowerCase = 0;
342 ldep->de_StartCluster = pmp->pm_rootdirblk;
343 /* de_FileSize will be filled in further down */
345 ldep->de_StartCluster = MSDOSFSROOT;
346 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
349 * fill in time and date so that dos2unixtime() doesn't
350 * spit up when called from msdosfs_getattr() with root
354 ldep->de_CTime = 0x0000; /* 00:00:00 */
355 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
356 | (1 << DD_DAY_SHIFT);
358 ldep->de_ADate = ldep->de_CDate;
359 ldep->de_MTime = ldep->de_CTime;
360 ldep->de_MDate = ldep->de_CDate;
361 /* leave the other fields as garbage */
363 error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
366 * The denode does not contain anything useful, so
367 * it would be wrong to leave it on its hash chain.
368 * Arrange for vput() to just forget about it.
370 ldep->de_Name[0] = SLOT_DELETED;
376 DE_INTERNALIZE(ldep, direntptr);
381 * Fill in a few fields of the vnode and finish filling in the
382 * denode. Then return the address of the found denode.
384 if (ldep->de_Attributes & ATTR_DIRECTORY) {
386 * Since DOS directory entries that describe directories
387 * have 0 in the filesize field, we take this opportunity
388 * to find out the length of the directory and plug it into
389 * the denode structure.
394 * XXX Sometimes, these arrives that . entry have cluster
395 * number 0, when it shouldn't. Use real cluster number
396 * instead of what is written in directory entry.
398 if ((diroffset == 0) && (ldep->de_StartCluster != dirclust)) {
399 kprintf("deget(): . entry at clust %ld != %ld\n",
400 dirclust, ldep->de_StartCluster);
401 ldep->de_StartCluster = dirclust;
405 if (ldep->de_StartCluster != MSDOSFSROOT) {
406 error = pcbmap(ldep, 0xffff, NULL, &size, NULL);
407 if (error == E2BIG) {
408 ldep->de_FileSize = de_cn2off(pmp, size);
411 kprintf("deget(): pcbmap returned %d\n", error);
417 SETHIGH(ldep->de_modrev, tv.tv_sec);
418 SETLOW(ldep->de_modrev, tv.tv_usec * 4294);
419 ldep->de_devvp = pmp->pm_devvp;
420 vref(ldep->de_devvp);
421 vinitvmio(nvp, ldep->de_FileSize);
423 * Leave nvp locked and refd so the returned inode is effectively
431 deupdat(struct denode *dep, int waitfor)
435 struct direntry *dirp;
438 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
441 DETIMES(dep, &ts, &ts, &ts);
442 if ((dep->de_flag & DE_MODIFIED) == 0)
444 dep->de_flag &= ~DE_MODIFIED;
445 if (dep->de_Attributes & ATTR_DIRECTORY)
447 if (dep->de_refcnt <= 0)
449 error = readde(dep, &bp, &dirp);
452 DE_EXTERNALIZE(dirp, dep);
462 * Truncate the file described by dep to the length specified by length.
465 detrunc(struct denode *dep, u_long length, int flags)
473 int isadir = dep->de_Attributes & ATTR_DIRECTORY;
475 struct msdosfsmount *pmp = dep->de_pmp;
478 kprintf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
482 * Disallow attempts to truncate the root directory since it is of
483 * fixed size. That's just the way dos filesystems are. We use
484 * the VROOT bit in the vnode because checking for the directory
485 * bit and a startcluster of 0 in the denode is not adequate to
486 * recognize the root directory at this point in a file or
489 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
490 kprintf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
491 dep->de_dirclust, dep->de_diroffset);
496 if (dep->de_FileSize < length) {
497 vnode_pager_setsize(DETOV(dep), length);
498 return deextend(dep, length);
502 * If the desired length is 0 then remember the starting cluster of
503 * the file and set the StartCluster field in the directory entry
504 * to 0. If the desired length is not zero, then get the number of
505 * the last cluster in the shortened file. Then get the number of
506 * the first cluster in the part of the file that is to be freed.
507 * Then set the next cluster pointer in the last cluster of the
508 * file to CLUST_EOFE.
511 chaintofree = dep->de_StartCluster;
512 dep->de_StartCluster = 0;
515 error = pcbmap(dep, de_clcount(pmp, length) - 1,
516 NULL, &eofentry, NULL);
519 kprintf("detrunc(): pcbmap fails %d\n", error);
525 fc_purge(dep, de_clcount(pmp, length));
528 * If the new length is not a multiple of the cluster size then we
529 * must zero the tail end of the new last cluster in case it
530 * becomes part of the file again because of a seek.
532 if ((boff = length & pmp->pm_crbomask) != 0) {
534 bn = xcntobn(pmp, eofentry);
535 error = bread(pmp->pm_devvp, de_bntodoff(pmp, bn), pmp->pm_bpcluster, &bp);
537 cn = de_cluster(pmp, length);
538 error = bread(DETOV(dep), de_cn2doff(pmp, cn), pmp->pm_bpcluster, &bp);
543 kprintf("detrunc(): bread fails %d\n", error);
548 * is this the right place for it?
550 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
558 * Write out the updated directory entry. Even if the update fails
559 * we free the trailing clusters.
561 dep->de_FileSize = length;
563 dep->de_flag |= DE_UPDATE|DE_MODIFIED;
564 allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster);
567 kprintf("detrunc(): vtruncbuf error %d\n", allerror);
569 error = deupdat(dep, 1);
570 if (error && (allerror == 0))
573 kprintf("detrunc(): allerror %d, eofentry %lu\n",
578 * If we need to break the cluster chain for the file then do it
581 if (eofentry != ~0) {
582 error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
583 &chaintofree, CLUST_EOFE);
586 kprintf("detrunc(): fatentry errors %d\n", error);
590 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
595 * Now free the clusters removed from the file because of the
598 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
599 freeclusterchain(pmp, chaintofree);
605 * Extend the file described by dep to length specified by length.
608 deextend(struct denode *dep, u_long length)
610 struct msdosfsmount *pmp = dep->de_pmp;
615 * The root of a DOS filesystem cannot be extended.
617 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
621 * Directories cannot be extended.
623 if (dep->de_Attributes & ATTR_DIRECTORY)
626 if (length <= dep->de_FileSize)
627 panic("deextend: file too large");
630 * Compute the number of clusters to allocate.
632 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
634 if (count > pmp->pm_freeclustercount)
636 error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
638 /* truncate the added clusters away again */
639 detrunc(dep, dep->de_FileSize, 0);
643 dep->de_FileSize = length;
644 dep->de_flag |= DE_UPDATE|DE_MODIFIED;
645 return (deupdat(dep, 1));
649 * msdosfs_reclaim(struct vnode *a_vp)
652 msdosfs_reclaim(struct vop_reclaim_args *ap)
654 struct vnode *vp = ap->a_vp;
655 struct denode *dep = VTODE(vp);
658 kprintf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
659 dep, dep ? dep->de_Name : "?", dep ? dep->de_refcnt : -1);
662 if (prtactive && vp->v_usecount != 0)
663 vprint("msdosfs_reclaim(): pushing active", vp);
665 * Remove the denode from its hash chain.
669 msdosfs_hashrem(dep);
671 vrele(dep->de_devvp);
674 kfree(dep, M_MSDOSFSNODE);
680 * msdosfs_inactive(struct vnode *a_vp, struct thread *a_td)
683 msdosfs_inactive(struct vop_inactive_args *ap)
685 struct vnode *vp = ap->a_vp;
686 struct denode *dep = VTODE(vp);
690 kprintf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
693 if (prtactive && vp->v_usecount != 0)
694 vprint("msdosfs_inactive(): pushing active", vp);
697 * Ignore denodes related to stale file handles.
699 if (dep->de_Name[0] == SLOT_DELETED)
703 * If the file has been deleted and it is on a read/write
704 * filesystem, then truncate the file, and mark the directory slot
705 * as empty. (This may not be necessary for the dos filesystem.)
708 kprintf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
709 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
711 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
712 error = detrunc(dep, (u_long) 0, 0);
713 dep->de_flag |= DE_UPDATE;
714 dep->de_Name[0] = SLOT_DELETED;
720 * If we are done with the denode, reclaim it
721 * so that it can be reused immediately.
724 kprintf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", vp->v_usecount,
727 if (dep->de_Name[0] == SLOT_DELETED)