1/* $FreeBSD$ */
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
72static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part");
73
74static int
75de_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) || (de->de_refcnt <= 0);
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 */
97int
98deget(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: de_vncmpf will explicitly skip any denodes that do not have
128	 * a de_refcnt > 0.  This insures that that we do not attempt to use
129	 * a denode that represents an unlinked but still open file.
130	 * These files are not to be accessible even when the directory
131	 * entry that represented the file happens to be reused while the
132	 * deleted file is still open.
133	 */
134	inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset;
135
136	error = vfs_hash_get(mntp, inode, LK_EXCLUSIVE, curthread, &nvp,
137	    de_vncmpf, &inode);
138	if (error)
139		return (error);
140	if (nvp != NULL) {
141		*depp = VTODE(nvp);
142		KASSERT((*depp)->de_dirclust == dirclust, ("wrong dirclust"));
143		KASSERT((*depp)->de_diroffset == diroffset, ("wrong diroffset"));
144		return (0);
145	}
146	ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO);
147
148	/*
149	 * Directory entry was not in cache, have to create a vnode and
150	 * copy it from the passed disk buffer.
151	 */
152	/* getnewvnode() does a VREF() on the vnode */
153	error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp);
154	if (error) {
155		*depp = NULL;
156		free(ldep, M_MSDOSFSNODE);
157		return error;
158	}
159	nvp->v_data = ldep;
160	ldep->de_vnode = nvp;
161	ldep->de_flag = 0;
162	ldep->de_dirclust = dirclust;
163	ldep->de_diroffset = diroffset;
164	ldep->de_inode = inode;
165	lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL);
166	fc_purge(ldep, 0);	/* init the FAT cache for this denode */
167	error = insmntque(nvp, mntp);
168	if (error != 0) {
169		free(ldep, M_MSDOSFSNODE);
170		*depp = NULL;
171		return (error);
172	}
173	error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp,
174	    de_vncmpf, &inode);
175	if (error) {
176		*depp = NULL;
177		return (error);
178	}
179	if (xvp != NULL) {
180		*depp = xvp->v_data;
181		return (0);
182	}
183
184	ldep->de_pmp = pmp;
185	ldep->de_refcnt = 1;
186	/*
187	 * Copy the directory entry into the denode area of the vnode.
188	 */
189	if ((dirclust == MSDOSFSROOT
190	     || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
191	    && diroffset == MSDOSFSROOT_OFS) {
192		/*
193		 * Directory entry for the root directory. There isn't one,
194		 * so we manufacture one. We should probably rummage
195		 * through the root directory and find a label entry (if it
196		 * exists), and then use the time and date from that entry
197		 * as the time and date for the root denode.
198		 */
199		nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
200
201		ldep->de_Attributes = ATTR_DIRECTORY;
202		ldep->de_LowerCase = 0;
203		if (FAT32(pmp))
204			ldep->de_StartCluster = pmp->pm_rootdirblk;
205			/* de_FileSize will be filled in further down */
206		else {
207			ldep->de_StartCluster = MSDOSFSROOT;
208			ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
209		}
210		/*
211		 * fill in time and date so that fattime2timespec() doesn't
212		 * spit up when called from msdosfs_getattr() with root
213		 * denode
214		 */
215		ldep->de_CHun = 0;
216		ldep->de_CTime = 0x0000;	/* 00:00:00	 */
217		ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
218		    | (1 << DD_DAY_SHIFT);
219		/* Jan 1, 1980	 */
220		ldep->de_ADate = ldep->de_CDate;
221		ldep->de_MTime = ldep->de_CTime;
222		ldep->de_MDate = ldep->de_CDate;
223		/* leave the other fields as garbage */
224	} else {
225		error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
226		if (error) {
227			/*
228			 * The denode does not contain anything useful, so
229			 * it would be wrong to leave it on its hash chain.
230			 * Arrange for vput() to just forget about it.
231			 */
232			ldep->de_Name[0] = SLOT_DELETED;
233
234			vput(nvp);
235			*depp = NULL;
236			return (error);
237		}
238		(void)DE_INTERNALIZE(ldep, direntptr);
239		brelse(bp);
240	}
241
242	/*
243	 * Fill in a few fields of the vnode and finish filling in the
244	 * denode.  Then return the address of the found denode.
245	 */
246	if (ldep->de_Attributes & ATTR_DIRECTORY) {
247		/*
248		 * Since DOS directory entries that describe directories
249		 * have 0 in the filesize field, we take this opportunity
250		 * to find out the length of the directory and plug it into
251		 * the denode structure.
252		 */
253		u_long size;
254
255		/*
256		 * XXX it sometimes happens that the "." entry has cluster
257		 * number 0 when it shouldn't.  Use the actual cluster number
258		 * instead of what is written in directory entry.
259		 */
260		if (diroffset == 0 && ldep->de_StartCluster != dirclust) {
261#ifdef MSDOSFS_DEBUG
262			printf("deget(): \".\" entry at clust %lu != %lu\n",
263			    dirclust, ldep->de_StartCluster);
264#endif
265			ldep->de_StartCluster = dirclust;
266		}
267
268		nvp->v_type = VDIR;
269		if (ldep->de_StartCluster != MSDOSFSROOT) {
270			error = pcbmap(ldep, 0xffff, 0, &size, 0);
271			if (error == E2BIG) {
272				ldep->de_FileSize = de_cn2off(pmp, size);
273				error = 0;
274			} else {
275#ifdef MSDOSFS_DEBUG
276				printf("deget(): pcbmap returned %d\n", error);
277#endif
278			}
279		}
280	} else
281		nvp->v_type = VREG;
282	ldep->de_modrev = init_va_filerev();
283	*depp = ldep;
284	return (0);
285}
286
287int
288deupdat(struct denode *dep, int waitfor)
289{
290	struct direntry dir;
291	struct timespec ts;
292	struct buf *bp;
293	struct direntry *dirp;
294	int error;
295
296	if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) {
297		dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS |
298		    DE_MODIFIED);
299		return (0);
300	}
301	vfs_timestamp(&ts);
302	DETIMES(dep, &ts, &ts, &ts);
303	if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0)
304		return (0);
305	dep->de_flag &= ~DE_MODIFIED;
306	if (DETOV(dep)->v_vflag & VV_ROOT)
307		return (EINVAL);
308	if (dep->de_refcnt <= 0)
309		return (0);
310	error = readde(dep, &bp, &dirp);
311	if (error)
312		return (error);
313	DE_EXTERNALIZE(&dir, dep);
314	if (bcmp(dirp, &dir, sizeof(dir)) == 0) {
315		if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) {
316			brelse(bp);
317			return (0);
318		}
319	} else
320		*dirp = dir;
321	if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0)
322		bp->b_flags |= B_CLUSTEROK;
323	if (waitfor)
324		error = bwrite(bp);
325	else if (vm_page_count_severe() || buf_dirty_count_severe())
326		bawrite(bp);
327	else
328		bdwrite(bp);
329	return (error);
330}
331
332/*
333 * Truncate the file described by dep to the length specified by length.
334 */
335int
336detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred)
337{
338	int error;
339	int allerror;
340	u_long eofentry;
341	u_long chaintofree;
342	daddr_t bn;
343	int boff;
344	int isadir = dep->de_Attributes & ATTR_DIRECTORY;
345	struct buf *bp;
346	struct msdosfsmount *pmp = dep->de_pmp;
347
348#ifdef MSDOSFS_DEBUG
349	printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
350#endif
351
352	/*
353	 * Disallow attempts to truncate the root directory since it is of
354	 * fixed size.  That's just the way dos filesystems are.  We use
355	 * the VROOT bit in the vnode because checking for the directory
356	 * bit and a startcluster of 0 in the denode is not adequate to
357	 * recognize the root directory at this point in a file or
358	 * directory's life.
359	 */
360	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
361#ifdef MSDOSFS_DEBUG
362		printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
363		    dep->de_dirclust, dep->de_diroffset);
364#endif
365		return (EINVAL);
366	}
367
368	if (dep->de_FileSize < length) {
369		vnode_pager_setsize(DETOV(dep), length);
370		return deextend(dep, length, cred);
371	}
372
373	/*
374	 * If the desired length is 0 then remember the starting cluster of
375	 * the file and set the StartCluster field in the directory entry
376	 * to 0.  If the desired length is not zero, then get the number of
377	 * the last cluster in the shortened file.  Then get the number of
378	 * the first cluster in the part of the file that is to be freed.
379	 * Then set the next cluster pointer in the last cluster of the
380	 * file to CLUST_EOFE.
381	 */
382	if (length == 0) {
383		chaintofree = dep->de_StartCluster;
384		dep->de_StartCluster = 0;
385		eofentry = ~0;
386	} else {
387		error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
388			       &eofentry, 0);
389		if (error) {
390#ifdef MSDOSFS_DEBUG
391			printf("detrunc(): pcbmap fails %d\n", error);
392#endif
393			return (error);
394		}
395	}
396
397	fc_purge(dep, de_clcount(pmp, length));
398
399	/*
400	 * If the new length is not a multiple of the cluster size then we
401	 * must zero the tail end of the new last cluster in case it
402	 * becomes part of the file again because of a seek.
403	 */
404	if ((boff = length & pmp->pm_crbomask) != 0) {
405		if (isadir) {
406			bn = cntobn(pmp, eofentry);
407			error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
408			    NOCRED, &bp);
409		} else {
410			error = bread(DETOV(dep), de_cluster(pmp, length),
411			    pmp->pm_bpcluster, cred, &bp);
412		}
413		if (error) {
414#ifdef MSDOSFS_DEBUG
415			printf("detrunc(): bread fails %d\n", error);
416#endif
417			return (error);
418		}
419		memset(bp->b_data + boff, 0, pmp->pm_bpcluster - boff);
420		if ((flags & IO_SYNC) != 0)
421			bwrite(bp);
422		else
423			bdwrite(bp);
424	}
425
426	/*
427	 * Write out the updated directory entry.  Even if the update fails
428	 * we free the trailing clusters.
429	 */
430	dep->de_FileSize = length;
431	if (!isadir)
432		dep->de_flag |= DE_UPDATE | DE_MODIFIED;
433	allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster);
434#ifdef MSDOSFS_DEBUG
435	if (allerror)
436		printf("detrunc(): vtruncbuf error %d\n", allerror);
437#endif
438	error = deupdat(dep, !DOINGASYNC((DETOV(dep))));
439	if (error != 0 && allerror == 0)
440		allerror = error;
441#ifdef MSDOSFS_DEBUG
442	printf("detrunc(): allerror %d, eofentry %lu\n",
443	       allerror, eofentry);
444#endif
445
446	/*
447	 * If we need to break the cluster chain for the file then do it
448	 * now.
449	 */
450	if (eofentry != ~0) {
451		error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
452				 &chaintofree, CLUST_EOFE);
453		if (error) {
454#ifdef MSDOSFS_DEBUG
455			printf("detrunc(): fatentry errors %d\n", error);
456#endif
457			return (error);
458		}
459		fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
460			    eofentry);
461	}
462
463	/*
464	 * Now free the clusters removed from the file because of the
465	 * truncation.
466	 */
467	if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
468		freeclusterchain(pmp, chaintofree);
469
470	return (allerror);
471}
472
473/*
474 * Extend the file described by dep to length specified by length.
475 */
476int
477deextend(struct denode *dep, u_long length, struct ucred *cred)
478{
479	struct msdosfsmount *pmp = dep->de_pmp;
480	u_long count;
481	int error;
482
483	/*
484	 * The root of a DOS filesystem cannot be extended.
485	 */
486	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
487		return (EINVAL);
488
489	/*
490	 * Directories cannot be extended.
491	 */
492	if (dep->de_Attributes & ATTR_DIRECTORY)
493		return (EISDIR);
494
495	if (length <= dep->de_FileSize)
496		panic("deextend: file too large");
497
498	/*
499	 * Compute the number of clusters to allocate.
500	 */
501	count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
502	if (count > 0) {
503		if (count > pmp->pm_freeclustercount)
504			return (ENOSPC);
505		error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
506		if (error) {
507			/* truncate the added clusters away again */
508			(void) detrunc(dep, dep->de_FileSize, 0, cred);
509			return (error);
510		}
511	}
512	dep->de_FileSize = length;
513	dep->de_flag |= DE_UPDATE | DE_MODIFIED;
514	return (deupdat(dep, !DOINGASYNC(DETOV(dep))));
515}
516
517/*
518 * Move a denode to its correct hash queue after the file it represents has
519 * been moved to a new directory.
520 */
521void
522reinsert(struct denode *dep)
523{
524	struct vnode *vp;
525
526	/*
527	 * Fix up the denode cache.  If the denode is for a directory,
528	 * there is nothing to do since the hash is based on the starting
529	 * cluster of the directory file and that hasn't changed.  If for a
530	 * file the hash is based on the location of the directory entry,
531	 * so we must remove it from the cache and re-enter it with the
532	 * hash based on the new location of the directory entry.
533	 */
534#if 0
535	if (dep->de_Attributes & ATTR_DIRECTORY)
536		return;
537#endif
538	vp = DETOV(dep);
539	dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust +
540	    dep->de_diroffset;
541	vfs_hash_rehash(vp, dep->de_inode);
542}
543
544int
545msdosfs_reclaim(struct vop_reclaim_args *ap)
546{
547	struct vnode *vp = ap->a_vp;
548	struct denode *dep = VTODE(vp);
549
550#ifdef MSDOSFS_DEBUG
551	printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
552	    dep, dep->de_Name, dep->de_refcnt);
553#endif
554
555	/*
556	 * Destroy the vm object and flush associated pages.
557	 */
558	vnode_destroy_vobject(vp);
559	/*
560	 * Remove the denode from its hash chain.
561	 */
562	vfs_hash_remove(vp);
563	/*
564	 * Purge old data structures associated with the denode.
565	 */
566#if 0 /* XXX */
567	dep->de_flag = 0;
568#endif
569	free(dep, M_MSDOSFSNODE);
570	vp->v_data = NULL;
571
572	return (0);
573}
574
575int
576msdosfs_inactive(struct vop_inactive_args *ap)
577{
578	struct vnode *vp = ap->a_vp;
579	struct denode *dep = VTODE(vp);
580	int error = 0;
581
582#ifdef MSDOSFS_DEBUG
583	printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
584#endif
585
586	/*
587	 * Ignore denodes related to stale file handles.
588	 */
589	if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
590		goto out;
591
592	/*
593	 * If the file has been deleted and it is on a read/write
594	 * filesystem, then truncate the file, and mark the directory slot
595	 * as empty.  (This may not be necessary for the dos filesystem.)
596	 */
597#ifdef MSDOSFS_DEBUG
598	printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %llx, MNT_RDONLY %llx\n",
599	    dep, dep->de_refcnt, (unsigned long long)vp->v_mount->mnt_flag,
600	    (unsigned long long)MNT_RDONLY);
601#endif
602	if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
603		error = detrunc(dep, (u_long) 0, 0, NOCRED);
604		dep->de_flag |= DE_UPDATE;
605		dep->de_Name[0] = SLOT_DELETED;
606	}
607	deupdat(dep, 0);
608
609out:
610	/*
611	 * If we are done with the denode, reclaim it
612	 * so that it can be reused immediately.
613	 */
614#ifdef MSDOSFS_DEBUG
615	printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n",
616	       vrefcnt(vp), dep->de_Name[0]);
617#endif
618	if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
619		vrecycle(vp);
620	return (error);
621}
622