1 /* $NetBSD: msdosfs_vnops.c,v 1.19 2017/04/13 17:10:12 christos Exp $ */
4 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
5 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by TooLs GmbH.
20 * 4. The name of TooLs GmbH may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 * Written by Paul Popelka (paulp@uts.amdahl.com)
37 * You can do anything you want with this software, just don't say you wrote
38 * it, and don't remove this notice.
40 * This software is provided "as is".
42 * The author supplies this software to be publicly redistributed on the
43 * understanding that the author is not responsible for the correct
44 * functioning of this software in any circumstances and is not liable for
45 * any damages caused by this software.
49 #if HAVE_NBTOOL_CONFIG_H
50 #include "nbtool_config.h"
53 #include <sys/cdefs.h>
54 __FBSDID("$FreeBSD$");
56 #include <sys/param.h>
63 #include <fs/msdosfs/bpb.h>
64 #include <fs/msdosfs/direntry.h>
65 #include <fs/msdosfs/denode.h>
66 #include <fs/msdosfs/msdosfsmount.h>
67 #include <fs/msdosfs/fat.h>
73 #define DPRINTF(a) printf a
80 * In the ufs filesystem the inodes, superblocks, and indirect blocks are
81 * read/written using the vnode for the filesystem. Blocks that represent
82 * the contents of a file are read/written using the vnode for the file
83 * (including directories when they are read/written as files). This
84 * presents problems for the dos filesystem because data that should be in
85 * an inode (if dos had them) resides in the directory itself. Since we
86 * must update directory entries without the benefit of having the vnode
87 * for the directory we must use the vnode for the filesystem. This means
88 * that when a directory is actually read/written (via read, write, or
89 * readdir, or seek) we must use the vnode for the filesystem instead of
90 * the vnode for the directory as would happen in ufs. This is to insure we
91 * retrieve the correct block from the buffer cache since the hash value is
92 * based upon the vnode address and the desired block number.
95 static int msdosfs_wfile(const char *, struct denode *, fsnode *);
98 msdosfs_times(struct msdosfsmount *pmp, struct denode *dep,
99 const struct stat *st)
107 #ifndef HAVE_NBTOOL_CONFIG_H
108 at = st->st_atimespec;
109 mt = st->st_mtimespec;
111 at.tv_sec = st->st_atime;
113 mt.tv_sec = st->st_mtime;
116 unix2dostime(&at, pmp->pm_gmtoff, &dep->de_ADate, NULL, NULL);
117 unix2dostime(&mt, pmp->pm_gmtoff, &dep->de_MDate, &dep->de_MTime, NULL);
121 * When we search a directory the blocks containing directory entries are
122 * read and examined. The directory entries contain information that would
123 * normally be in the inode of a unix filesystem. This means that some of
124 * a directory's contents may also be in memory resident denodes (sort of
125 * an inode). This can cause problems if we are searching while some other
126 * process is modifying a directory. To prevent one process from accessing
127 * incompletely modified directory information we depend upon being the
128 * sole owner of a directory block. bread/brelse provide this service.
129 * This being the case, when a process modifies a directory it must first
130 * acquire the disk block that contains the directory entry to be modified.
131 * Then update the disk block and the denode, and then write the disk block
132 * out to disk. This way disk blocks containing directory entries and in
133 * memory denode's will be in synch.
136 msdosfs_findslot(struct denode *dp, struct componentname *cnp)
147 struct msdosfsmount *pmp;
149 struct direntry *dep;
150 u_char dosfilename[12];
152 int chksum = -1, chksum_ok;
157 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename,
158 cnp->cn_namelen, 0)) {
164 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
165 cnp->cn_namelen, pmp->pm_flags & MSDOSFSMNT_UTF8) + 1;
169 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr,
170 cnp->cn_namelen, pmp->pm_flags & MSDOSFSMNT_UTF8) + 1;
174 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
178 * Suppress search for slots unless creating
179 * file and at end of pathname, in which case
180 * we watch for a place to put the new file in
181 * case it doesn't already exist.
184 DPRINTF(("%s(): dos filename: %s\n", __func__, dosfilename));
186 * Search the directory pointed at by vdp for the name pointed at
187 * by cnp->cn_nameptr.
190 * The outer loop ranges over the clusters that make up the
191 * directory. Note that the root directory is different from all
192 * other directories. It has a fixed number of blocks that are not
193 * part of the pool of allocatable clusters. So, we treat it a
194 * little differently. The root directory starts at "cluster" 0.
197 for (frcn = 0; diroff < dp->de_FileSize; frcn++) {
198 if ((error = pcbmap(dp, frcn, &bn, &cluster, &blsize)) != 0) {
203 error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn), blsize,
208 for (blkoff = 0; blkoff < blsize;
209 blkoff += sizeof(struct direntry),
210 diroff += sizeof(struct direntry)) {
211 dep = (struct direntry *)((char *)bp->b_data + blkoff);
213 * If the slot is empty and we are still looking
214 * for an empty then remember this one. If the
215 * slot is not empty then check to see if it
216 * matches what we are looking for. If the slot
217 * has never been filled with anything, then the
218 * remainder of the directory has never been used,
219 * so there is no point in searching it.
221 if (dep->deName[0] == SLOT_EMPTY ||
222 dep->deName[0] == SLOT_DELETED) {
224 * Drop memory of previous long matches
228 if (slotcount < wincnt) {
232 if (dep->deName[0] == SLOT_EMPTY) {
238 * If there wasn't enough space for our
239 * winentries, forget about the empty space
241 if (slotcount < wincnt)
245 * Check for Win95 long filename entry
247 if (dep->deAttributes == ATTR_WIN95) {
248 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
251 chksum = winChkName((const u_char *)cnp->cn_nameptr,
253 (struct winentry *)dep,
255 pmp->pm_flags & MSDOSFSMNT_UTF8);
260 * Ignore volume labels (anywhere, not just
261 * the root directory).
263 if (dep->deAttributes & ATTR_VOLUME) {
269 * Check for a checksum or name match
271 chksum_ok = (chksum == winChksum(dep->deName));
273 && (!olddos || memcmp(dosfilename, dep->deName, 11))) {
277 DPRINTF(("%s(): match blkoff %d, diroff %d\n",
278 __func__, blkoff, diroff));
280 * Remember where this directory
281 * entry came from for whoever did
284 dp->de_fndoffset = diroff;
289 } /* for (blkoff = 0; .... */
291 * Release the buffer holding the directory cluster just
295 } /* for (frcn = 0; ; frcn++) */
299 * We hold no disk buffers at this point.
303 * If we get here we didn't find the entry we were looking for. But
304 * that's ok if we are creating or renaming and are at the end of
305 * the pathname and the directory hasn't been removed.
307 DPRINTF(("%s(): refcnt %ld, slotcount %d, slotoffset %d\n",
308 __func__, dp->de_refcnt, slotcount, slotoffset));
310 * Fixup the slot description to point to the place where
311 * we might put the new DOS direntry (putting the Win95
312 * long name entries before that)
318 if (wincnt > slotcount) {
319 slotoffset += sizeof(struct direntry) * (wincnt - slotcount);
323 * Return an indication of where the new directory
324 * entry should be put.
326 dp->de_fndoffset = slotoffset;
327 dp->de_fndcnt = wincnt - 1;
330 * We return with the directory locked, so that
331 * the parameters we set up above will still be
332 * valid if we actually decide to do a direnter().
333 * We return ni_vp == NULL to indicate that the entry
334 * does not currently exist; we leave a pointer to
335 * the (locked) directory inode in ndp->ni_dvp.
337 * NB - if the directory is unlocked, then this
338 * information cannot be used.
344 * Create a regular file. On entry the directory to contain the file being
345 * created is locked. We must release before we return.
348 msdosfs_mkfile(const char *path, struct denode *pdep, fsnode *node)
350 struct componentname cn;
351 struct denode ndirent;
354 struct stat *st = &node->inode->st;
355 struct msdosfsmount *pmp = pdep->de_pmp;
357 cn.cn_nameptr = node->name;
358 cn.cn_namelen = strlen(node->name);
360 DPRINTF(("%s(name %s, mode 0%o size %zu)\n", __func__, node->name,
361 st->st_mode, (size_t)st->st_size));
364 * If this is the root directory and there is no space left we
365 * can't do anything. This is because the root directory can not
368 if (pdep->de_StartCluster == MSDOSFSROOT
369 && pdep->de_fndoffset >= pdep->de_FileSize) {
375 * Create a directory entry for the file, then call createde() to
376 * have it installed. NOTE: DOS files are always executable. We
377 * use the absence of the owner write bit to make the file
380 memset(&ndirent, 0, sizeof(ndirent));
381 if ((error = uniqdosname(pdep, &cn, ndirent.de_Name)) != 0)
384 ndirent.de_Attributes = (st->st_mode & S_IWUSR) ?
385 ATTR_ARCHIVE : ATTR_ARCHIVE | ATTR_READONLY;
386 ndirent.de_StartCluster = 0;
387 ndirent.de_FileSize = 0;
388 ndirent.de_dev = pdep->de_dev;
389 ndirent.de_devvp = pdep->de_devvp;
390 ndirent.de_pmp = pdep->de_pmp;
391 ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
392 msdosfs_times(pmp, &ndirent, st);
393 if ((error = msdosfs_findslot(pdep, &cn)) != 0)
395 if ((error = createde(&ndirent, pdep, &dep, &cn)) != 0)
397 if ((error = msdosfs_wfile(path, dep, node)) != 0)
406 msdosfs_updatede(struct denode *dep)
409 struct direntry *dirp;
412 dep->de_flag &= ~DE_MODIFIED;
413 error = readde(dep, &bp, &dirp);
416 DE_EXTERNALIZE(dirp, dep);
422 * Write data to a file or directory.
425 msdosfs_wfile(const char *path, struct denode *dep, fsnode *node)
428 size_t osize = dep->de_FileSize;
429 struct stat *st = &node->inode->st;
431 struct msdosfsmount *pmp = dep->de_pmp;
436 error = 0; /* XXX: gcc/vax */
437 DPRINTF(("%s(diroff %lu, dirclust %lu, startcluster %lu)\n", __func__,
438 dep->de_diroffset, dep->de_dirclust, dep->de_StartCluster));
439 if (st->st_size == 0)
442 /* Don't bother to try to write files larger than the fs limit */
443 if (st->st_size > MSDOSFS_FILESIZE_MAX)
447 DPRINTF(("%s(nsize=%zu, osize=%zu)\n", __func__, nsize, osize));
449 if ((error = deextend(dep, nsize, NULL)) != 0)
451 if ((error = msdosfs_updatede(dep)) != 0)
455 if ((fd = open(path, O_RDONLY)) == -1) {
457 DPRINTF((1, "open %s: %s", path, strerror(error)));
461 if ((dat = mmap(0, nsize, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, 0))
464 DPRINTF(("%s: mmap %s: %s", __func__, node->name,
471 for (offs = 0; offs < nsize;) {
474 u_long on = offs & pmp->pm_crbomask;
476 cn = dep->de_StartCluster;
477 if (cn == MSDOSFSROOT) {
478 DPRINTF(("%s: bad lbn %lu", __func__, cn));
482 bn = cntobn(pmp, cn);
483 blsize = pmp->pm_bpcluster;
485 if ((error = pcbmap(dep, cn++, &bn, NULL, &blsize)) != 0) {
486 DPRINTF(("%s: pcbmap %lu", __func__, bn));
490 DPRINTF(("%s(cn=%lu, bn=%llu/%llu, blsize=%d)\n", __func__,
491 cn, (unsigned long long)bn,
492 (unsigned long long)de_bn2kb(pmp, bn), blsize));
493 if ((error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn), blsize,
495 DPRINTF(("bread %d\n", error));
498 cpsize = MIN((nsize - offs), blsize - on);
499 memcpy((char *)bp->b_data + on, dat + offs, cpsize);
512 static const struct {
514 struct direntry dotdot;
516 { ". ", " ", /* the . entry */
517 ATTR_DIRECTORY, /* file attribute */
519 0, { 0, 0 }, { 0, 0 }, /* create time & date */
520 { 0, 0 }, /* access date */
521 { 0, 0 }, /* high bits of start cluster */
522 { 210, 4 }, { 210, 4 }, /* modify time & date */
523 { 0, 0 }, /* startcluster */
524 { 0, 0, 0, 0 } /* filesize */
526 { ".. ", " ", /* the .. entry */
527 ATTR_DIRECTORY, /* file attribute */
529 0, { 0, 0 }, { 0, 0 }, /* create time & date */
530 { 0, 0 }, /* access date */
531 { 0, 0 }, /* high bits of start cluster */
532 { 210, 4 }, { 210, 4 }, /* modify time & date */
533 { 0, 0 }, /* startcluster */
534 { 0, 0, 0, 0 } /* filesize */
539 msdosfs_mkdire(const char *path, struct denode *pdep, fsnode *node) {
540 struct denode ndirent;
542 struct componentname cn;
543 struct stat *st = &node->inode->st;
544 struct msdosfsmount *pmp = pdep->de_pmp;
546 u_long newcluster, pcl, bn;
548 struct direntry *denp;
551 cn.cn_nameptr = node->name;
552 cn.cn_namelen = strlen(node->name);
554 * If this is the root directory and there is no space left we
555 * can't do anything. This is because the root directory can not
558 if (pdep->de_StartCluster == MSDOSFSROOT
559 && pdep->de_fndoffset >= pdep->de_FileSize) {
565 * Allocate a cluster to hold the about to be created directory.
567 error = clusteralloc(pmp, 0, 1, &newcluster, NULL);
571 memset(&ndirent, 0, sizeof(ndirent));
572 ndirent.de_pmp = pmp;
573 ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
574 msdosfs_times(pmp, &ndirent, st);
577 * Now fill the cluster with the "." and ".." entries. And write
578 * the cluster to disk. This way it is there for the parent
579 * directory to be pointing at if there were a crash.
581 bn = cntobn(pmp, newcluster);
582 lbn = de_bn2kb(pmp, bn);
583 DPRINTF(("%s(newcluster %lu, bn=%lu, lbn=%lu)\n", __func__, newcluster,
585 /* always succeeds */
586 bp = getblk(pmp->pm_devvp, lbn, pmp->pm_bpcluster, 0, 0);
587 memset(bp->b_data, 0, pmp->pm_bpcluster);
588 memcpy(bp->b_data, &dosdirtemplate, sizeof dosdirtemplate);
589 denp = (struct direntry *)bp->b_data;
590 putushort(denp[0].deStartCluster, newcluster);
591 putushort(denp[0].deCDate, ndirent.de_CDate);
592 putushort(denp[0].deCTime, ndirent.de_CTime);
593 denp[0].deCHundredth = ndirent.de_CHun;
594 putushort(denp[0].deADate, ndirent.de_ADate);
595 putushort(denp[0].deMDate, ndirent.de_MDate);
596 putushort(denp[0].deMTime, ndirent.de_MTime);
597 pcl = pdep->de_StartCluster;
598 DPRINTF(("%s(pcl %lu, rootdirblk=%lu)\n", __func__, pcl,
599 pmp->pm_rootdirblk));
600 if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
602 putushort(denp[1].deStartCluster, pcl);
603 putushort(denp[1].deCDate, ndirent.de_CDate);
604 putushort(denp[1].deCTime, ndirent.de_CTime);
605 denp[1].deCHundredth = ndirent.de_CHun;
606 putushort(denp[1].deADate, ndirent.de_ADate);
607 putushort(denp[1].deMDate, ndirent.de_MDate);
608 putushort(denp[1].deMTime, ndirent.de_MTime);
610 putushort(denp[0].deHighClust, newcluster >> 16);
611 putushort(denp[1].deHighClust, pdep->de_StartCluster >> 16);
613 putushort(denp[0].deHighClust, 0);
614 putushort(denp[1].deHighClust, 0);
617 if ((error = bwrite(bp)) != 0)
621 * Now build up a directory entry pointing to the newly allocated
622 * cluster. This will be written to an empty slot in the parent
625 if ((error = uniqdosname(pdep, &cn, ndirent.de_Name)) != 0)
628 ndirent.de_Attributes = ATTR_DIRECTORY;
629 ndirent.de_StartCluster = newcluster;
630 ndirent.de_FileSize = 0;
631 ndirent.de_dev = pdep->de_dev;
632 ndirent.de_devvp = pdep->de_devvp;
633 ndirent.de_pmp = pdep->de_pmp;
634 if ((error = msdosfs_findslot(pdep, &cn)) != 0)
636 if ((error = createde(&ndirent, pdep, &dep, &cn)) != 0)
638 if ((error = msdosfs_updatede(dep)) != 0)
643 clusterfree(pmp, newcluster, NULL);