1 /* $OpenBSD: msdosfs_vnops.c,v 1.143 2024/10/18 05:52:32 miod Exp $ */
2 /* $NetBSD: msdosfs_vnops.c,v 1.63 1997/10/17 11:24:19 ws Exp $ */
3
4 /*-
5 * Copyright (C) 2005 Thomas Wang.
6 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
7 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
8 * All rights reserved.
9 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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.
24 *
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.
35 */
36 /*
37 * Written by Paul Popelka (paulp@uts.amdahl.com)
38 *
39 * You can do anything you want with this software, just don't say you wrote
40 * it, and don't remove this notice.
41 *
42 * This software is provided "as is".
43 *
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.
48 *
49 * October 1992
50 */
51
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/namei.h>
55 #include <sys/resourcevar.h> /* defines plimit structure in proc struct */
56 #include <sys/fcntl.h> /* define FWRITE ... */
57 #include <sys/file.h>
58 #include <sys/stat.h>
59 #include <sys/buf.h>
60 #include <sys/proc.h>
61 #include <sys/mount.h>
62 #include <sys/vnode.h>
63 #include <sys/lock.h>
64 #include <sys/signalvar.h>
65 #include <sys/specdev.h> /* XXX */ /* defines v_rdev */
66 #include <sys/malloc.h>
67 #include <sys/pool.h>
68 #include <sys/dirent.h> /* defines dirent structure */
69 #include <sys/lockf.h>
70 #include <sys/unistd.h>
71
72 #include <msdosfs/bpb.h>
73 #include <msdosfs/direntry.h>
74 #include <msdosfs/denode.h>
75 #include <msdosfs/msdosfsmount.h>
76 #include <msdosfs/fat.h>
77
78 static uint32_t fileidhash(uint64_t);
79
80 int msdosfs_bmaparray(struct vnode *, uint32_t, daddr_t *, int *);
81 int msdosfs_kqfilter(void *);
82 int filt_msdosfsread(struct knote *, long);
83 int filt_msdosfswrite(struct knote *, long);
84 int filt_msdosfsvnode(struct knote *, long);
85 void filt_msdosfsdetach(struct knote *);
86
87 /*
88 * Some general notes:
89 *
90 * In the ufs filesystem the inodes, superblocks, and indirect blocks are
91 * read/written using the vnode for the filesystem. Blocks that represent
92 * the contents of a file are read/written using the vnode for the file
93 * (including directories when they are read/written as files). This
94 * presents problems for the dos filesystem because data that should be in
95 * an inode (if dos had them) resides in the directory itself. Since we
96 * must update directory entries without the benefit of having the vnode
97 * for the directory we must use the vnode for the filesystem. This means
98 * that when a directory is actually read/written (via read, write, or
99 * readdir, or seek) we must use the vnode for the filesystem instead of
100 * the vnode for the directory as would happen in ufs. This is to insure we
101 * retrieve the correct block from the buffer cache since the hash value is
102 * based upon the vnode address and the desired block number.
103 */
104
105 /*
106 * Create a regular file. On entry the directory to contain the file being
107 * created is locked. We must release before we return. We must also free
108 * the pathname buffer pointed at by cnp->cn_pnbuf, always on error, or
109 * only if the SAVESTART bit in cn_flags is clear on success.
110 */
111 int
msdosfs_create(void * v)112 msdosfs_create(void *v)
113 {
114 struct vop_create_args *ap = v;
115 struct componentname *cnp = ap->a_cnp;
116 struct denode ndirent;
117 struct denode *dep;
118 struct denode *pdep = VTODE(ap->a_dvp);
119 int error;
120 struct timespec ts;
121
122 #ifdef MSDOSFS_DEBUG
123 printf("msdosfs_create(cnp %p, vap %p\n", cnp, ap->a_vap);
124 #endif
125
126 /*
127 * If this is the root directory and there is no space left we
128 * can't do anything. This is because the root directory can not
129 * change size.
130 */
131 if (pdep->de_StartCluster == MSDOSFSROOT
132 && pdep->de_fndoffset >= pdep->de_FileSize) {
133 error = ENOSPC;
134 goto bad;
135 }
136
137 /*
138 * Create a directory entry for the file, then call createde() to
139 * have it installed. NOTE: DOS files are always executable. We
140 * use the absence of the owner write bit to make the file
141 * readonly.
142 */
143 #ifdef DIAGNOSTIC
144 if ((cnp->cn_flags & HASBUF) == 0)
145 panic("msdosfs_create: no name");
146 #endif
147 bzero(&ndirent, sizeof(ndirent));
148 if ((error = uniqdosname(pdep, cnp, ndirent.de_Name)) != 0)
149 goto bad;
150
151 ndirent.de_Attributes = (ap->a_vap->va_mode & VWRITE) ?
152 ATTR_ARCHIVE : ATTR_ARCHIVE | ATTR_READONLY;
153 ndirent.de_StartCluster = 0;
154 ndirent.de_FileSize = 0;
155 ndirent.de_dev = pdep->de_dev;
156 ndirent.de_devvp = pdep->de_devvp;
157 ndirent.de_pmp = pdep->de_pmp;
158 ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
159 getnanotime(&ts);
160 DETIMES(&ndirent, &ts, &ts, &ts);
161 if ((error = createde(&ndirent, pdep, &dep, cnp)) != 0)
162 goto bad;
163 if ((cnp->cn_flags & SAVESTART) == 0)
164 pool_put(&namei_pool, cnp->cn_pnbuf);
165 VN_KNOTE(ap->a_dvp, NOTE_WRITE);
166 *ap->a_vpp = DETOV(dep);
167 return (0);
168
169 bad:
170 pool_put(&namei_pool, cnp->cn_pnbuf);
171 return (error);
172 }
173
174 int
msdosfs_mknod(void * v)175 msdosfs_mknod(void *v)
176 {
177 struct vop_mknod_args *ap = v;
178
179 pool_put(&namei_pool, ap->a_cnp->cn_pnbuf);
180 VN_KNOTE(ap->a_dvp, NOTE_WRITE);
181 return (EINVAL);
182 }
183
184 int
msdosfs_open(void * v)185 msdosfs_open(void *v)
186 {
187 return (0);
188 }
189
190 int
msdosfs_close(void * v)191 msdosfs_close(void *v)
192 {
193 struct vop_close_args *ap = v;
194 struct vnode *vp = ap->a_vp;
195 struct denode *dep = VTODE(vp);
196 struct timespec ts;
197
198 if (vp->v_usecount > 1 && !VOP_ISLOCKED(vp)) {
199 getnanotime(&ts);
200 DETIMES(dep, &ts, &ts, &ts);
201 }
202 return (0);
203 }
204
205 int
msdosfs_access(void * v)206 msdosfs_access(void *v)
207 {
208 struct vop_access_args *ap = v;
209 struct denode *dep = VTODE(ap->a_vp);
210 struct msdosfsmount *pmp = dep->de_pmp;
211 mode_t dosmode;
212
213 dosmode = (S_IRUSR | S_IRGRP | S_IROTH);
214 if ((dep->de_Attributes & ATTR_READONLY) == 0)
215 dosmode |= (S_IWUSR | S_IWGRP | S_IWOTH);
216 if (dep->de_Attributes & ATTR_DIRECTORY)
217 dosmode |= (S_IXUSR | S_IXGRP | S_IXOTH);
218 dosmode &= pmp->pm_mask;
219
220 return (vaccess(ap->a_vp->v_type, dosmode, pmp->pm_uid, pmp->pm_gid,
221 ap->a_mode, ap->a_cred));
222 }
223
224 int
msdosfs_getattr(void * v)225 msdosfs_getattr(void *v)
226 {
227 struct vop_getattr_args *ap = v;
228 struct denode *dep = VTODE(ap->a_vp);
229 struct msdosfsmount *pmp = dep->de_pmp;
230 struct vattr *vap = ap->a_vap;
231 struct timespec ts;
232 uint32_t fileid;
233
234 getnanotime(&ts);
235 DETIMES(dep, &ts, &ts, &ts);
236 vap->va_fsid = dep->de_dev;
237
238 /*
239 * The following computation of the fileid must be the same as
240 * that used in msdosfs_readdir() to compute d_fileno. If not,
241 * pwd doesn't work.
242 *
243 * We now use the starting cluster number as the fileid/fileno.
244 * This works for both files and directories (including the root
245 * directory, on FAT32). Even on FAT32, this will at most be a
246 * 28-bit number, as the high 4 bits of FAT32 cluster numbers
247 * are reserved.
248 *
249 * However, we do need to do something for 0-length files, which
250 * will not have a starting cluster number.
251 *
252 * These files cannot be directories, since (except for /, which
253 * is special-cased anyway) directories contain entries for . and
254 * .., so must have non-zero length.
255 *
256 * In this case, we just create a non-cryptographic hash of the
257 * original fileid calculation, and set the top bit.
258 *
259 * This algorithm has the benefit that all directories, and all
260 * non-zero-length files, will have fileids that are persistent
261 * across mounts and reboots, and that cannot collide (as long
262 * as the filesystem is not corrupt). Zero-length files will
263 * have fileids that are persistent, but that may collide. We
264 * will just have to live with that.
265 */
266 fileid = dep->de_StartCluster;
267
268 if (dep->de_Attributes & ATTR_DIRECTORY) {
269 /* Special-case root */
270 if (dep->de_StartCluster == MSDOSFSROOT)
271 fileid = FAT32(pmp) ? pmp->pm_rootdirblk : 1;
272 } else {
273 if (dep->de_FileSize == 0) {
274 uint32_t dirsperblk;
275 uint64_t fileid64;
276
277 dirsperblk = pmp->pm_BytesPerSec /
278 sizeof(struct direntry);
279
280 fileid64 = (dep->de_dirclust == MSDOSFSROOT) ?
281 roottobn(pmp, 0) : cntobn(pmp, dep->de_dirclust);
282 fileid64 *= dirsperblk;
283 fileid64 += dep->de_diroffset / sizeof(struct direntry);
284
285 fileid = fileidhash(fileid64);
286 }
287 }
288
289 vap->va_fileid = fileid;
290 vap->va_mode = (S_IRUSR|S_IRGRP|S_IROTH);
291 if ((dep->de_Attributes & ATTR_READONLY) == 0)
292 vap->va_mode |= (S_IWUSR|S_IWGRP|S_IWOTH);
293 if (dep->de_Attributes & ATTR_DIRECTORY) {
294 vap->va_mode |= S_IFDIR;
295 vap->va_mode |= (vap->va_mode & S_IRUSR) ? S_IXUSR : 0;
296 vap->va_mode |= (vap->va_mode & S_IRGRP) ? S_IXGRP : 0;
297 vap->va_mode |= (vap->va_mode & S_IROTH) ? S_IXOTH : 0;
298 }
299 vap->va_mode &= dep->de_pmp->pm_mask;
300 vap->va_nlink = 1;
301 vap->va_gid = dep->de_pmp->pm_gid;
302 vap->va_uid = dep->de_pmp->pm_uid;
303 vap->va_rdev = 0;
304 vap->va_size = dep->de_FileSize;
305 dos2unixtime(dep->de_MDate, dep->de_MTime, 0, &vap->va_mtime);
306 if (dep->de_pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
307 dos2unixtime(dep->de_ADate, 0, 0, &vap->va_atime);
308 dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CTimeHundredth, &vap->va_ctime);
309 } else {
310 vap->va_atime = vap->va_mtime;
311 vap->va_ctime = vap->va_mtime;
312 }
313 vap->va_flags = 0;
314 if ((dep->de_Attributes & ATTR_ARCHIVE) == 0)
315 vap->va_flags |= SF_ARCHIVED;
316 vap->va_gen = 0;
317 vap->va_blocksize = dep->de_pmp->pm_bpcluster;
318 vap->va_bytes = (dep->de_FileSize + dep->de_pmp->pm_crbomask) &
319 ~(dep->de_pmp->pm_crbomask);
320 vap->va_type = ap->a_vp->v_type;
321 return (0);
322 }
323
324 int
msdosfs_setattr(void * v)325 msdosfs_setattr(void *v)
326 {
327 struct vop_setattr_args *ap = v;
328 struct vnode *vp = ap->a_vp;
329 struct denode *dep = VTODE(ap->a_vp);
330 struct msdosfsmount *pmp = dep->de_pmp;
331 struct vattr *vap = ap->a_vap;
332 struct ucred *cred = ap->a_cred;
333 int error = 0;
334
335 #ifdef MSDOSFS_DEBUG
336 printf("msdosfs_setattr(): vp %p, vap %p, cred %p, p %p\n",
337 ap->a_vp, vap, cred, ap->a_p);
338 #endif
339 if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
340 (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
341 (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
342 (vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
343 #ifdef MSDOSFS_DEBUG
344 printf("msdosfs_setattr(): returning EINVAL\n");
345 printf(" va_type %d, va_nlink %x, va_fsid %ld, "
346 "va_fileid %llx\n", vap->va_type, vap->va_nlink,
347 vap->va_fsid, (unsigned long long)vap->va_fileid);
348 printf(" va_blocksize %lx, va_rdev %x, va_bytes %llx, "
349 "va_gen %lx\n", vap->va_blocksize,
350 (unsigned int)vap->va_rdev,
351 (unsigned long long)vap->va_bytes, vap->va_gen);
352 #endif
353 return (EINVAL);
354 }
355 if (vap->va_flags != VNOVAL) {
356 if (vp->v_mount->mnt_flag & MNT_RDONLY)
357 return (EINVAL);
358 if (cred->cr_uid != pmp->pm_uid) {
359 error = suser_ucred(cred);
360 if (error)
361 return (error);
362 }
363 /*
364 * We are very inconsistent about handling unsupported
365 * attributes. We ignored the access time and the
366 * read and execute bits. We were strict for the other
367 * attributes.
368 *
369 * Here we are strict, stricter than ufs in not allowing
370 * users to attempt to set SF_SETTABLE bits or anyone to
371 * set unsupported bits. However, we ignore attempts to
372 * set ATTR_ARCHIVE for directories `cp -pr' from a more
373 * sensible filesystem attempts it a lot.
374 */
375 if (vap->va_flags & SF_SETTABLE) {
376 error = suser_ucred(cred);
377 if (error)
378 return (error);
379 }
380 if (vap->va_flags & ~SF_ARCHIVED)
381 return EOPNOTSUPP;
382 if (vap->va_flags & SF_ARCHIVED)
383 dep->de_Attributes &= ~ATTR_ARCHIVE;
384 else if (!(dep->de_Attributes & ATTR_DIRECTORY))
385 dep->de_Attributes |= ATTR_ARCHIVE;
386 dep->de_flag |= DE_MODIFIED;
387 }
388
389 if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
390 uid_t uid;
391 gid_t gid;
392
393 if (vp->v_mount->mnt_flag & MNT_RDONLY)
394 return (EINVAL);
395 uid = vap->va_uid;
396 if (uid == (uid_t)VNOVAL)
397 uid = pmp->pm_uid;
398 gid = vap->va_gid;
399 if (gid == (gid_t)VNOVAL)
400 gid = pmp->pm_gid;
401 if (cred->cr_uid != pmp->pm_uid || uid != pmp->pm_uid ||
402 (gid != pmp->pm_gid && !groupmember(gid, cred))) {
403 error = suser_ucred(cred);
404 if (error)
405 return (error);
406 }
407 if (uid != pmp->pm_uid || gid != pmp->pm_gid)
408 return EINVAL;
409 }
410
411 if (vap->va_size != VNOVAL) {
412 switch (vp->v_type) {
413 case VDIR:
414 return (EISDIR);
415 case VREG:
416 /*
417 * Truncation is only supported for regular files,
418 * Disallow it if the filesystem is read-only.
419 */
420 if (vp->v_mount->mnt_flag & MNT_RDONLY)
421 return (EINVAL);
422 break;
423 default:
424 /*
425 * According to POSIX, the result is unspecified
426 * for file types other than regular files,
427 * directories and shared memory objects. We
428 * don't support any file types except regular
429 * files and directories in this file system, so
430 * this (default) case is unreachable and can do
431 * anything. Keep falling through to detrunc()
432 * for now.
433 */
434 break;
435 }
436 error = detrunc(dep, vap->va_size, 0, cred, ap->a_p);
437 if (error)
438 return error;
439 }
440 if ((vap->va_vaflags & VA_UTIMES_CHANGE) ||
441 vap->va_atime.tv_nsec != VNOVAL ||
442 vap->va_mtime.tv_nsec != VNOVAL) {
443 if (vp->v_mount->mnt_flag & MNT_RDONLY)
444 return (EINVAL);
445 if (cred->cr_uid != pmp->pm_uid &&
446 (error = suser_ucred(cred)) &&
447 ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
448 (error = VOP_ACCESS(ap->a_vp, VWRITE, cred, ap->a_p))))
449 return (error);
450 if (vp->v_type != VDIR) {
451 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) == 0 &&
452 vap->va_atime.tv_nsec != VNOVAL) {
453 dep->de_flag &= ~DE_ACCESS;
454 unix2dostime(&vap->va_atime, &dep->de_ADate,
455 NULL, NULL);
456 }
457 if (vap->va_mtime.tv_nsec != VNOVAL) {
458 dep->de_flag &= ~DE_UPDATE;
459 unix2dostime(&vap->va_mtime, &dep->de_MDate,
460 &dep->de_MTime, NULL);
461 }
462 dep->de_Attributes |= ATTR_ARCHIVE;
463 dep->de_flag |= DE_MODIFIED;
464 }
465 }
466 /*
467 * DOS files only have the ability to have their writability
468 * attribute set, so we use the owner write bit to set the readonly
469 * attribute.
470 */
471 if (vap->va_mode != (mode_t)VNOVAL) {
472 if (vp->v_mount->mnt_flag & MNT_RDONLY)
473 return (EINVAL);
474 if (cred->cr_uid != pmp->pm_uid) {
475 error = suser_ucred(cred);
476 if (error)
477 return (error);
478 }
479 if (vp->v_type != VDIR) {
480 /* We ignore the read and execute bits. */
481 if (vap->va_mode & VWRITE)
482 dep->de_Attributes &= ~ATTR_READONLY;
483 else
484 dep->de_Attributes |= ATTR_READONLY;
485 dep->de_Attributes |= ATTR_ARCHIVE;
486 dep->de_flag |= DE_MODIFIED;
487 }
488 }
489 VN_KNOTE(ap->a_vp, NOTE_ATTRIB);
490 return (deupdat(dep, 1));
491 }
492
493 int
msdosfs_read(void * v)494 msdosfs_read(void *v)
495 {
496 struct vop_read_args *ap = v;
497 struct vnode *vp = ap->a_vp;
498 struct denode *dep = VTODE(vp);
499 struct msdosfsmount *pmp = dep->de_pmp;
500 struct uio *uio = ap->a_uio;
501 int isadir, error = 0;
502 uint32_t n, diff, size, on;
503 struct buf *bp;
504 uint32_t cn;
505 daddr_t bn;
506
507 /*
508 * If they didn't ask for any data, then we are done.
509 */
510 if (uio->uio_resid == 0)
511 return (0);
512 if (uio->uio_offset < 0)
513 return (EINVAL);
514
515 isadir = dep->de_Attributes & ATTR_DIRECTORY;
516 do {
517 if (uio->uio_offset >= dep->de_FileSize)
518 return (0);
519
520 cn = de_cluster(pmp, uio->uio_offset);
521 size = pmp->pm_bpcluster;
522 on = uio->uio_offset & pmp->pm_crbomask;
523 n = ulmin(pmp->pm_bpcluster - on, uio->uio_resid);
524
525 /*
526 * de_FileSize is uint32_t, and we know that uio_offset <
527 * de_FileSize, so uio->uio_offset < 2^32. Therefore
528 * the cast to uint32_t on the next line is safe.
529 */
530 diff = dep->de_FileSize - (uint32_t)uio->uio_offset;
531 if (diff < n)
532 n = diff;
533
534 /*
535 * If we are operating on a directory file then be sure to
536 * do i/o with the vnode for the filesystem instead of the
537 * vnode for the directory.
538 */
539 if (isadir) {
540 /* convert cluster # to block # */
541 error = pcbmap(dep, cn, &bn, 0, &size);
542 if (error)
543 return (error);
544 error = bread(pmp->pm_devvp, bn, size, &bp);
545 } else {
546 if (de_cn2off(pmp, cn + 1) >= dep->de_FileSize)
547 error = bread(vp, cn, size, &bp);
548 else
549 error = bread_cluster(vp, cn, size, &bp);
550 }
551 n = min(n, pmp->pm_bpcluster - bp->b_resid);
552 if (error) {
553 brelse(bp);
554 return (error);
555 }
556 error = uiomove(bp->b_data + on, n, uio);
557 brelse(bp);
558 } while (error == 0 && uio->uio_resid > 0 && n != 0);
559 if (!isadir && !(vp->v_mount->mnt_flag & MNT_NOATIME))
560 dep->de_flag |= DE_ACCESS;
561 return (error);
562 }
563
564 /*
565 * Write data to a file or directory.
566 */
567 int
msdosfs_write(void * v)568 msdosfs_write(void *v)
569 {
570 struct vop_write_args *ap = v;
571 uint32_t n, croffset;
572 size_t resid;
573 ssize_t overrun;
574 int extended = 0;
575 uint32_t osize;
576 int error = 0;
577 uint32_t count, lastcn, cn;
578 struct buf *bp;
579 int ioflag = ap->a_ioflag;
580 struct uio *uio = ap->a_uio;
581 struct vnode *vp = ap->a_vp;
582 struct vnode *thisvp;
583 struct denode *dep = VTODE(vp);
584 struct msdosfsmount *pmp = dep->de_pmp;
585 struct ucred *cred = ap->a_cred;
586
587 #ifdef MSDOSFS_DEBUG
588 printf("msdosfs_write(vp %p, uio %p, ioflag %08x, cred %p\n",
589 vp, uio, ioflag, cred);
590 printf("msdosfs_write(): diroff %d, dirclust %d, startcluster %d\n",
591 dep->de_diroffset, dep->de_dirclust, dep->de_StartCluster);
592 #endif
593
594 switch (vp->v_type) {
595 case VREG:
596 if (ioflag & IO_APPEND)
597 uio->uio_offset = dep->de_FileSize;
598 thisvp = vp;
599 break;
600 case VDIR:
601 return EISDIR;
602 default:
603 panic("msdosfs_write(): bad file type");
604 }
605
606 if (uio->uio_offset < 0)
607 return (EINVAL);
608
609 if (uio->uio_resid == 0)
610 return (0);
611
612 /* Don't bother to try to write files larger than the f/s limit */
613 if (uio->uio_offset > MSDOSFS_FILESIZE_MAX ||
614 uio->uio_resid > (MSDOSFS_FILESIZE_MAX - uio->uio_offset))
615 return (EFBIG);
616
617 /* do the filesize rlimit check */
618 if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
619 return (error);
620
621 /*
622 * If the offset we are starting the write at is beyond the end of
623 * the file, then they've done a seek. Unix filesystems allow
624 * files with holes in them, DOS doesn't so we must fill the hole
625 * with zeroed blocks.
626 */
627 if (uio->uio_offset > dep->de_FileSize) {
628 if ((error = deextend(dep, uio->uio_offset, cred)) != 0)
629 goto out;
630 }
631
632 /*
633 * Remember some values in case the write fails.
634 */
635 resid = uio->uio_resid;
636 osize = dep->de_FileSize;
637
638 /*
639 * If we write beyond the end of the file, extend it to its ultimate
640 * size ahead of the time to hopefully get a contiguous area.
641 */
642 if (uio->uio_offset + resid > osize) {
643 extended = 1;
644 count = de_clcount(pmp, uio->uio_offset + resid) -
645 de_clcount(pmp, osize);
646 if ((error = extendfile(dep, count, NULL, NULL, 0)) &&
647 (error != ENOSPC || (ioflag & IO_UNIT)))
648 goto errexit;
649 lastcn = dep->de_fc[FC_LASTFC].fc_frcn;
650 } else
651 lastcn = de_clcount(pmp, osize) - 1;
652
653 do {
654 croffset = uio->uio_offset & pmp->pm_crbomask;
655 cn = de_cluster(pmp, uio->uio_offset);
656
657 if (cn > lastcn) {
658 error = ENOSPC;
659 break;
660 }
661
662 if (croffset == 0 &&
663 (de_cluster(pmp, uio->uio_offset + uio->uio_resid) > cn ||
664 (uio->uio_offset + uio->uio_resid) >= dep->de_FileSize)) {
665 /*
666 * If either the whole cluster gets written,
667 * or we write the cluster from its start beyond EOF,
668 * then no need to read data from disk.
669 */
670 bp = getblk(thisvp, cn, pmp->pm_bpcluster, 0, INFSLP);
671 clrbuf(bp);
672 /*
673 * Do the bmap now, since pcbmap needs buffers
674 * for the fat table. (see msdosfs_strategy)
675 */
676 if (bp->b_blkno == bp->b_lblkno) {
677 error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno, 0, 0);
678 if (error)
679 bp->b_blkno = -1;
680 }
681 if (bp->b_blkno == -1) {
682 brelse(bp);
683 if (!error)
684 error = EIO; /* XXX */
685 break;
686 }
687 } else {
688 /*
689 * The block we need to write into exists, so
690 * read it in.
691 */
692 error = bread(thisvp, cn, pmp->pm_bpcluster, &bp);
693 if (error) {
694 brelse(bp);
695 break;
696 }
697 }
698
699 n = ulmin(uio->uio_resid, pmp->pm_bpcluster - croffset);
700 if (uio->uio_offset + n > dep->de_FileSize) {
701 dep->de_FileSize = uio->uio_offset + n;
702 uvm_vnp_setsize(vp, dep->de_FileSize);
703 }
704 uvm_vnp_uncache(vp);
705 /*
706 * Should these vnode_pager_* functions be done on dir
707 * files?
708 */
709
710 /*
711 * Copy the data from user space into the buf header.
712 */
713 error = uiomove(bp->b_data + croffset, n, uio);
714
715 /*
716 * If they want this synchronous then write it and wait for
717 * it. Otherwise, if on a cluster boundary write it
718 * asynchronously so we can move on to the next block
719 * without delay. Otherwise do a delayed write because we
720 * may want to write some more into the block later.
721 */
722 #if 0
723 if (ioflag & IO_NOCACHE)
724 bp->b_flags |= B_NOCACHE;
725 #endif
726 if (ioflag & IO_SYNC)
727 (void) bwrite(bp);
728 else if (n + croffset == pmp->pm_bpcluster)
729 bawrite(bp);
730 else
731 bdwrite(bp);
732 dep->de_flag |= DE_UPDATE;
733 } while (error == 0 && uio->uio_resid > 0);
734
735 if (resid > uio->uio_resid)
736 VN_KNOTE(ap->a_vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
737
738 if (dep->de_FileSize < osize)
739 VN_KNOTE(ap->a_vp, NOTE_TRUNCATE);
740
741 /*
742 * If the write failed and they want us to, truncate the file back
743 * to the size it was before the write was attempted.
744 */
745 errexit:
746 if (error) {
747 if (ioflag & IO_UNIT) {
748 detrunc(dep, osize, ioflag & IO_SYNC, NOCRED, curproc);
749 uio->uio_offset -= resid - uio->uio_resid;
750 uio->uio_resid = resid;
751 } else {
752 detrunc(dep, dep->de_FileSize, ioflag & IO_SYNC, NOCRED, curproc);
753 if (uio->uio_resid != resid)
754 error = 0;
755 }
756 } else if (ioflag & IO_SYNC)
757 error = deupdat(dep, 1);
758
759 out:
760 /* correct the result for writes clamped by vn_fsizechk() */
761 uio->uio_resid += overrun;
762 return (error);
763 }
764
765 int
msdosfs_ioctl(void * v)766 msdosfs_ioctl(void *v)
767 {
768 return (ENOTTY);
769 }
770
771 /*
772 * Flush the blocks of a file to disk.
773 *
774 * This function is worthless for vnodes that represent directories. Maybe we
775 * could just do a sync if they try an fsync on a directory file.
776 */
777 int
msdosfs_fsync(void * v)778 msdosfs_fsync(void *v)
779 {
780 struct vop_fsync_args *ap = v;
781 struct vnode *vp = ap->a_vp;
782
783 vflushbuf(vp, ap->a_waitfor == MNT_WAIT);
784 return (deupdat(VTODE(vp), ap->a_waitfor == MNT_WAIT));
785 }
786
787 /*
788 * Flush the blocks of a file to disk.
789 *
790 * This function is worthless for vnodes that represent directories. Maybe we
791 * could just do a sync if they try an fsync on a directory file.
792 */
793 int
msdosfs_remove(void * v)794 msdosfs_remove(void *v)
795 {
796 struct vop_remove_args *ap = v;
797 struct denode *dep = VTODE(ap->a_vp);
798 struct denode *ddep = VTODE(ap->a_dvp);
799 int error;
800
801 if (ap->a_vp->v_type == VDIR)
802 error = EPERM;
803 else
804 error = removede(ddep, dep);
805
806 VN_KNOTE(ap->a_vp, NOTE_DELETE);
807 VN_KNOTE(ap->a_dvp, NOTE_WRITE);
808
809 #ifdef MSDOSFS_DEBUG
810 printf("msdosfs_remove(), dep %p, v_usecount %d\n", dep,
811 ap->a_vp->v_usecount);
812 #endif
813 return (error);
814 }
815
816 /*
817 * DOS filesystems don't know what links are. But since we already called
818 * msdosfs_lookup() with create and lockparent, the parent is locked so we
819 * have to free it before we return the error.
820 */
821 int
msdosfs_link(void * v)822 msdosfs_link(void *v)
823 {
824 struct vop_link_args *ap = v;
825
826 VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
827 vput(ap->a_dvp);
828 return (EOPNOTSUPP);
829 }
830
831 /*
832 * Renames on files require moving the denode to a new hash queue since the
833 * denode's location is used to compute which hash queue to put the file
834 * in. Unless it is a rename in place. For example "mv a b".
835 *
836 * What follows is the basic algorithm:
837 *
838 * if (file move) {
839 * if (dest file exists) {
840 * remove dest file
841 * }
842 * if (dest and src in same directory) {
843 * rewrite name in existing directory slot
844 * } else {
845 * write new entry in dest directory
846 * update offset and dirclust in denode
847 * move denode to new hash chain
848 * clear old directory entry
849 * }
850 * } else {
851 * directory move
852 * if (dest directory exists) {
853 * if (dest is not empty) {
854 * return ENOTEMPTY
855 * }
856 * remove dest directory
857 * }
858 * if (dest and src in same directory) {
859 * rewrite name in existing entry
860 * } else {
861 * be sure dest is not a child of src directory
862 * write entry in dest directory
863 * update "." and ".." in moved directory
864 * update offset and dirclust in denode
865 * move denode to new hash chain
866 * clear old directory entry for moved directory
867 * }
868 * }
869 *
870 * On entry:
871 * source's parent directory is unlocked
872 * source file or directory is unlocked
873 * destination's parent directory is locked
874 * destination file or directory is locked if it exists
875 *
876 * On exit:
877 * all denodes should be released
878 *
879 * Notes:
880 * I'm not sure how the memory containing the pathnames pointed at by the
881 * componentname structures is freed, there may be some memory bleeding
882 * for each rename done.
883 */
884 int
msdosfs_rename(void * v)885 msdosfs_rename(void *v)
886 {
887 struct vop_rename_args *ap = v;
888 struct vnode *tvp = ap->a_tvp;
889 struct vnode *tdvp = ap->a_tdvp;
890 struct vnode *fvp = ap->a_fvp;
891 struct vnode *fdvp = ap->a_fdvp;
892 struct componentname *tcnp = ap->a_tcnp;
893 struct componentname *fcnp = ap->a_fcnp;
894 struct denode *ip, *xp, *dp, *zp;
895 u_char toname[11], oldname[11];
896 uint32_t from_diroffset, to_diroffset;
897 u_char to_count;
898 int doingdirectory = 0, newparent = 0;
899 int error;
900 uint32_t cn, pcl;
901 daddr_t bn;
902 struct msdosfsmount *pmp;
903 struct direntry *dotdotp;
904 struct buf *bp;
905
906 pmp = VFSTOMSDOSFS(fdvp->v_mount);
907
908 #ifdef DIAGNOSTIC
909 if ((tcnp->cn_flags & HASBUF) == 0 ||
910 (fcnp->cn_flags & HASBUF) == 0)
911 panic("msdosfs_rename: no name");
912 #endif
913 /*
914 * Check for cross-device rename.
915 */
916 if ((fvp->v_mount != tdvp->v_mount) ||
917 (tvp && (fvp->v_mount != tvp->v_mount))) {
918 error = EXDEV;
919 abortit:
920 VOP_ABORTOP(tdvp, tcnp);
921 if (tdvp == tvp)
922 vrele(tdvp);
923 else
924 vput(tdvp);
925 if (tvp)
926 vput(tvp);
927 VOP_ABORTOP(fdvp, fcnp);
928 vrele(fdvp);
929 vrele(fvp);
930 return (error);
931 }
932
933 /*
934 * If source and dest are the same, do nothing.
935 */
936 if (tvp == fvp) {
937 error = 0;
938 goto abortit;
939 }
940
941 /* */
942 if ((error = vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY)) != 0)
943 goto abortit;
944 dp = VTODE(fdvp);
945 ip = VTODE(fvp);
946
947 /*
948 * Be sure we are not renaming ".", "..", or an alias of ".". This
949 * leads to a crippled directory tree. It's pretty tough to do a
950 * "ls" or "pwd" with the "." directory entry missing, and "cd .."
951 * doesn't work if the ".." entry is missing.
952 */
953 if (ip->de_Attributes & ATTR_DIRECTORY) {
954 /*
955 * Avoid ".", "..", and aliases of "." for obvious reasons.
956 */
957 if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
958 dp == ip ||
959 (fcnp->cn_flags & ISDOTDOT) ||
960 (tcnp->cn_flags & ISDOTDOT) ||
961 (ip->de_flag & DE_RENAME)) {
962 VOP_UNLOCK(fvp);
963 error = EINVAL;
964 goto abortit;
965 }
966 ip->de_flag |= DE_RENAME;
967 doingdirectory++;
968 }
969 VN_KNOTE(fdvp, NOTE_WRITE); /* XXX right place? */
970
971 /*
972 * When the target exists, both the directory
973 * and target vnodes are returned locked.
974 */
975 dp = VTODE(tdvp);
976 xp = tvp ? VTODE(tvp) : NULL;
977 /*
978 * Remember direntry place to use for destination
979 */
980 to_diroffset = dp->de_fndoffset;
981 to_count = dp->de_fndcnt;
982
983 /*
984 * If ".." must be changed (ie the directory gets a new
985 * parent) then the source directory must not be in the
986 * directory hierarchy above the target, as this would
987 * orphan everything below the source directory. Also
988 * the user must have write permission in the source so
989 * as to be able to change "..". We must repeat the call
990 * to namei, as the parent directory is unlocked by the
991 * call to doscheckpath().
992 */
993 error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
994 VOP_UNLOCK(fvp);
995 if (VTODE(fdvp)->de_StartCluster != VTODE(tdvp)->de_StartCluster)
996 newparent = 1;
997 vrele(fdvp);
998 if (doingdirectory && newparent) {
999 if (error) /* write access check above */
1000 goto bad1;
1001 if (xp != NULL)
1002 vput(tvp);
1003 /*
1004 * doscheckpath() vput()'s dp,
1005 * so we have to do a relookup afterwards
1006 */
1007 if ((error = doscheckpath(ip, dp)) != 0)
1008 goto out;
1009 if ((tcnp->cn_flags & SAVESTART) == 0)
1010 panic("msdosfs_rename: lost to startdir");
1011 if ((error = vfs_relookup(tdvp, &tvp, tcnp)) != 0)
1012 goto out;
1013 dp = VTODE(tdvp);
1014 xp = tvp ? VTODE(tvp) : NULL;
1015 }
1016
1017 VN_KNOTE(tdvp, NOTE_WRITE);
1018
1019 if (xp != NULL) {
1020 /*
1021 * Target must be empty if a directory and have no links
1022 * to it. Also, ensure source and target are compatible
1023 * (both directories, or both not directories).
1024 */
1025 if (xp->de_Attributes & ATTR_DIRECTORY) {
1026 if (!dosdirempty(xp)) {
1027 error = ENOTEMPTY;
1028 goto bad1;
1029 }
1030 if (!doingdirectory) {
1031 error = ENOTDIR;
1032 goto bad1;
1033 }
1034 cache_purge(tdvp);
1035 } else if (doingdirectory) {
1036 error = EISDIR;
1037 goto bad1;
1038 }
1039 if ((error = removede(dp, xp)) != 0)
1040 goto bad1;
1041 VN_KNOTE(tvp, NOTE_DELETE);
1042 vput(tvp);
1043 xp = NULL;
1044 }
1045
1046 /*
1047 * Convert the filename in tcnp into a dos filename. We copy this
1048 * into the denode and directory entry for the destination
1049 * file/directory.
1050 */
1051 if ((error = uniqdosname(VTODE(tdvp), tcnp, toname)) != 0)
1052 goto bad1;
1053
1054 /*
1055 * Since from wasn't locked at various places above,
1056 * have to do a relookup here.
1057 */
1058 fcnp->cn_flags &= ~MODMASK;
1059 fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
1060 if ((fcnp->cn_flags & SAVESTART) == 0)
1061 panic("msdosfs_rename: lost from startdir");
1062 if (!newparent)
1063 VOP_UNLOCK(tdvp);
1064 (void) vfs_relookup(fdvp, &fvp, fcnp);
1065 if (fvp == NULL) {
1066 /*
1067 * From name has disappeared.
1068 */
1069 if (doingdirectory)
1070 panic("rename: lost dir entry");
1071 vrele(ap->a_fvp);
1072 if (newparent)
1073 VOP_UNLOCK(tdvp);
1074 vrele(tdvp);
1075 return 0;
1076 }
1077 xp = VTODE(fvp);
1078 zp = VTODE(fdvp);
1079 from_diroffset = zp->de_fndoffset;
1080
1081 /*
1082 * Ensure that the directory entry still exists and has not
1083 * changed till now. If the source is a file the entry may
1084 * have been unlinked or renamed. In either case there is
1085 * no further work to be done. If the source is a directory
1086 * then it cannot have been rmdir'ed or renamed; this is
1087 * prohibited by the DE_RENAME flag.
1088 */
1089 if (xp != ip) {
1090 if (doingdirectory)
1091 panic("rename: lost dir entry");
1092 vrele(ap->a_fvp);
1093 if (newparent)
1094 VOP_UNLOCK(fdvp);
1095 xp = NULL;
1096 } else {
1097 vrele(fvp);
1098 xp = NULL;
1099
1100 /*
1101 * First write a new entry in the destination
1102 * directory and mark the entry in the source directory
1103 * as deleted. Then move the denode to the correct hash
1104 * chain for its new location in the filesystem. And, if
1105 * we moved a directory, then update its .. entry to point
1106 * to the new parent directory.
1107 */
1108 bcopy(ip->de_Name, oldname, 11);
1109 bcopy(toname, ip->de_Name, 11); /* update denode */
1110 dp->de_fndoffset = to_diroffset;
1111 dp->de_fndcnt = to_count;
1112 error = createde(ip, dp, NULL, tcnp);
1113 if (error) {
1114 bcopy(oldname, ip->de_Name, 11);
1115 if (newparent)
1116 VOP_UNLOCK(fdvp);
1117 goto bad;
1118 }
1119 ip->de_refcnt++;
1120 zp->de_fndoffset = from_diroffset;
1121 if ((error = removede(zp, ip)) != 0) {
1122 /* XXX should really panic here, fs is corrupt */
1123 if (newparent)
1124 VOP_UNLOCK(fdvp);
1125 goto bad;
1126 }
1127
1128 cache_purge(fvp);
1129
1130 if (!doingdirectory) {
1131 error = pcbmap(dp, de_cluster(pmp, to_diroffset), 0,
1132 &ip->de_dirclust, 0);
1133 if (error) {
1134 /* XXX should really panic here, fs is corrupt */
1135 if (newparent)
1136 VOP_UNLOCK(fdvp);
1137 goto bad;
1138 }
1139 ip->de_diroffset = to_diroffset;
1140 if (ip->de_dirclust != MSDOSFSROOT)
1141 ip->de_diroffset &= pmp->pm_crbomask;
1142 }
1143 reinsert(ip);
1144 if (newparent)
1145 VOP_UNLOCK(fdvp);
1146 }
1147
1148 /*
1149 * If we moved a directory to a new parent directory, then we must
1150 * fixup the ".." entry in the moved directory.
1151 */
1152 if (doingdirectory && newparent) {
1153 cn = ip->de_StartCluster;
1154 if (cn == MSDOSFSROOT) {
1155 /* this should never happen */
1156 panic("msdosfs_rename: updating .. in root directory?");
1157 } else
1158 bn = cntobn(pmp, cn);
1159 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, &bp);
1160 if (error) {
1161 /* XXX should really panic here, fs is corrupt */
1162 brelse(bp);
1163 goto bad;
1164 }
1165 dotdotp = (struct direntry *)bp->b_data;
1166 putushort(dotdotp[0].deStartCluster, cn);
1167 pcl = dp->de_StartCluster;
1168 if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
1169 pcl = 0;
1170 putushort(dotdotp[1].deStartCluster, pcl);
1171 if (FAT32(pmp)) {
1172 putushort(dotdotp[0].deHighClust, cn >> 16);
1173 putushort(dotdotp[1].deHighClust, pcl >> 16);
1174 }
1175 if ((error = bwrite(bp)) != 0) {
1176 /* XXX should really panic here, fs is corrupt */
1177 goto bad;
1178 }
1179 }
1180
1181 VN_KNOTE(fvp, NOTE_RENAME);
1182
1183 bad:
1184 VOP_UNLOCK(fvp);
1185 vrele(fdvp);
1186 bad1:
1187 if (xp)
1188 vput(tvp);
1189 vput(tdvp);
1190 out:
1191 ip->de_flag &= ~DE_RENAME;
1192 vrele(fvp);
1193 return (error);
1194
1195 }
1196
1197 struct {
1198 struct direntry dot;
1199 struct direntry dotdot;
1200 } dosdirtemplate = {
1201 { ". ", " ", /* the . entry */
1202 ATTR_DIRECTORY, /* file attribute */
1203 CASE_LOWER_BASE | CASE_LOWER_EXT, /* lower case */
1204 0, /* create time 100ths */
1205 { 0, 0 }, { 0, 0 }, /* create time & date */
1206 { 0, 0 }, /* access date */
1207 { 0, 0 }, /* high bits of start cluster */
1208 { 210, 4 }, { 210, 4 }, /* modify time & date */
1209 { 0, 0 }, /* startcluster */
1210 { 0, 0, 0, 0 } /* filesize */
1211 },
1212 { ".. ", " ", /* the .. entry */
1213 ATTR_DIRECTORY, /* file attribute */
1214 CASE_LOWER_BASE | CASE_LOWER_EXT, /* lower case */
1215 0, /* create time 100ths */
1216 { 0, 0 }, { 0, 0 }, /* create time & date */
1217 { 0, 0 }, /* access date */
1218 { 0, 0 }, /* high bits of start cluster */
1219 { 210, 4 }, { 210, 4 }, /* modify time & date */
1220 { 0, 0 }, /* startcluster */
1221 { 0, 0, 0, 0 } /* filesize */
1222 }
1223 };
1224
1225 int
msdosfs_mkdir(void * v)1226 msdosfs_mkdir(void *v)
1227 {
1228 struct vop_mkdir_args *ap = v;
1229 struct componentname *cnp = ap->a_cnp;
1230 struct denode ndirent;
1231 struct denode *dep;
1232 struct denode *pdep = VTODE(ap->a_dvp);
1233 int error;
1234 daddr_t bn;
1235 uint32_t newcluster, pcl;
1236 struct direntry *denp;
1237 struct msdosfsmount *pmp = pdep->de_pmp;
1238 struct buf *bp;
1239 struct timespec ts;
1240
1241 /*
1242 * If this is the root directory and there is no space left we
1243 * can't do anything. This is because the root directory can not
1244 * change size.
1245 */
1246 if (pdep->de_StartCluster == MSDOSFSROOT
1247 && pdep->de_fndoffset >= pdep->de_FileSize) {
1248 error = ENOSPC;
1249 goto bad2;
1250 }
1251
1252 /*
1253 * Allocate a cluster to hold the about to be created directory.
1254 */
1255 error = clusteralloc(pmp, 0, 1, &newcluster, NULL);
1256 if (error)
1257 goto bad2;
1258
1259 bzero(&ndirent, sizeof(ndirent));
1260 ndirent.de_pmp = pmp;
1261 ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
1262 getnanotime(&ts);
1263 DETIMES(&ndirent, &ts, &ts, &ts);
1264
1265 /*
1266 * Now fill the cluster with the "." and ".." entries. And write
1267 * the cluster to disk. This way it is there for the parent
1268 * directory to be pointing at if there were a crash.
1269 */
1270 bn = cntobn(pmp, newcluster);
1271 /* always succeeds */
1272 bp = getblk(pmp->pm_devvp, bn, pmp->pm_bpcluster, 0, INFSLP);
1273 bzero(bp->b_data, pmp->pm_bpcluster);
1274 bcopy(&dosdirtemplate, bp->b_data, sizeof dosdirtemplate);
1275 denp = (struct direntry *)bp->b_data;
1276 putushort(denp[0].deStartCluster, newcluster);
1277 putushort(denp[0].deCDate, ndirent.de_CDate);
1278 putushort(denp[0].deCTime, ndirent.de_CTime);
1279 denp[0].deCTimeHundredth = ndirent.de_CTimeHundredth;
1280 putushort(denp[0].deADate, ndirent.de_ADate);
1281 putushort(denp[0].deMDate, ndirent.de_MDate);
1282 putushort(denp[0].deMTime, ndirent.de_MTime);
1283 pcl = pdep->de_StartCluster;
1284 if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
1285 pcl = 0;
1286 putushort(denp[1].deStartCluster, pcl);
1287 putushort(denp[1].deCDate, ndirent.de_CDate);
1288 putushort(denp[1].deCTime, ndirent.de_CTime);
1289 denp[1].deCTimeHundredth = ndirent.de_CTimeHundredth;
1290 putushort(denp[1].deADate, ndirent.de_ADate);
1291 putushort(denp[1].deMDate, ndirent.de_MDate);
1292 putushort(denp[1].deMTime, ndirent.de_MTime);
1293 if (FAT32(pmp)) {
1294 putushort(denp[0].deHighClust, newcluster >> 16);
1295 putushort(denp[1].deHighClust, pdep->de_StartCluster >> 16);
1296 }
1297
1298 if ((error = bwrite(bp)) != 0)
1299 goto bad;
1300
1301 /*
1302 * Now build up a directory entry pointing to the newly allocated
1303 * cluster. This will be written to an empty slot in the parent
1304 * directory.
1305 */
1306 #ifdef DIAGNOSTIC
1307 if ((cnp->cn_flags & HASBUF) == 0)
1308 panic("msdosfs_mkdir: no name");
1309 #endif
1310 if ((error = uniqdosname(pdep, cnp, ndirent.de_Name)) != 0)
1311 goto bad;
1312
1313 ndirent.de_Attributes = ATTR_DIRECTORY;
1314 ndirent.de_StartCluster = newcluster;
1315 ndirent.de_FileSize = 0;
1316 ndirent.de_dev = pdep->de_dev;
1317 ndirent.de_devvp = pdep->de_devvp;
1318 if ((error = createde(&ndirent, pdep, &dep, cnp)) != 0)
1319 goto bad;
1320 if ((cnp->cn_flags & SAVESTART) == 0)
1321 pool_put(&namei_pool, cnp->cn_pnbuf);
1322 VN_KNOTE(ap->a_dvp, NOTE_WRITE | NOTE_LINK);
1323 vput(ap->a_dvp);
1324 *ap->a_vpp = DETOV(dep);
1325 return (0);
1326
1327 bad:
1328 clusterfree(pmp, newcluster, NULL);
1329 bad2:
1330 pool_put(&namei_pool, cnp->cn_pnbuf);
1331 vput(ap->a_dvp);
1332 return (error);
1333 }
1334
1335 int
msdosfs_rmdir(void * v)1336 msdosfs_rmdir(void *v)
1337 {
1338 struct vop_rmdir_args *ap = v;
1339 struct vnode *vp = ap->a_vp;
1340 struct vnode *dvp = ap->a_dvp;
1341 struct componentname *cnp = ap->a_cnp;
1342 struct denode *ip, *dp;
1343 int error;
1344
1345 ip = VTODE(vp);
1346 dp = VTODE(dvp);
1347 /*
1348 * Verify the directory is empty (and valid).
1349 * (Rmdir ".." won't be valid since
1350 * ".." will contain a reference to
1351 * the current directory and thus be
1352 * non-empty.)
1353 */
1354 error = 0;
1355 if (!dosdirempty(ip) || ip->de_flag & DE_RENAME) {
1356 error = ENOTEMPTY;
1357 goto out;
1358 }
1359
1360 VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
1361
1362 /*
1363 * Delete the entry from the directory. For dos filesystems this
1364 * gets rid of the directory entry on disk, the in memory copy
1365 * still exists but the de_refcnt is <= 0. This prevents it from
1366 * being found by deget(). When the vput() on dep is done we give
1367 * up access and eventually msdosfs_reclaim() will be called which
1368 * will remove it from the denode cache.
1369 */
1370 if ((error = removede(dp, ip)) != 0)
1371 goto out;
1372 /*
1373 * This is where we decrement the link count in the parent
1374 * directory. Since dos filesystems don't do this we just purge
1375 * the name cache and let go of the parent directory denode.
1376 */
1377 cache_purge(dvp);
1378 vput(dvp);
1379 dvp = NULL;
1380 /*
1381 * Truncate the directory that is being deleted.
1382 */
1383 error = detrunc(ip, (uint32_t)0, IO_SYNC, cnp->cn_cred, cnp->cn_proc);
1384 cache_purge(vp);
1385 out:
1386 if (dvp)
1387 vput(dvp);
1388 VN_KNOTE(vp, NOTE_DELETE);
1389 vput(vp);
1390 return (error);
1391 }
1392
1393 /*
1394 * DOS filesystems don't know what symlinks are.
1395 */
1396 int
msdosfs_symlink(void * v)1397 msdosfs_symlink(void *v)
1398 {
1399 struct vop_symlink_args *ap = v;
1400
1401 VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
1402 vput(ap->a_dvp);
1403 return (EOPNOTSUPP);
1404 }
1405
1406 int
msdosfs_readdir(void * v)1407 msdosfs_readdir(void *v)
1408 {
1409 struct vop_readdir_args *ap = v;
1410 int error = 0;
1411 int diff;
1412 long n;
1413 int blsize;
1414 long on;
1415 long lost;
1416 long count;
1417 uint32_t dirsperblk;
1418 uint32_t cn, lbn;
1419 uint32_t fileno;
1420 long bias = 0;
1421 daddr_t bn;
1422 struct buf *bp;
1423 struct denode *dep = VTODE(ap->a_vp);
1424 struct msdosfsmount *pmp = dep->de_pmp;
1425 struct direntry *dentp;
1426 struct dirent dirbuf;
1427 struct uio *uio = ap->a_uio;
1428 off_t offset, wlast = -1;
1429 int chksum = -1;
1430
1431 #ifdef MSDOSFS_DEBUG
1432 printf("msdosfs_readdir(): vp %p, uio %p, cred %p, eofflagp %p\n",
1433 ap->a_vp, uio, ap->a_cred, ap->a_eofflag);
1434 #endif
1435
1436 /*
1437 * msdosfs_readdir() won't operate properly on regular files since
1438 * it does i/o only with the filesystem vnode, and hence can
1439 * retrieve the wrong block from the buffer cache for a plain file.
1440 * So, fail attempts to readdir() on a plain file.
1441 */
1442 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0)
1443 return (ENOTDIR);
1444
1445 /*
1446 * To be safe, initialize dirbuf
1447 */
1448 bzero(&dirbuf, sizeof(dirbuf));
1449
1450 /*
1451 * If the user buffer is smaller than the size of one dos directory
1452 * entry or the file offset is not a multiple of the size of a
1453 * directory entry, then we fail the read.
1454 */
1455 count = uio->uio_resid & ~(sizeof(struct direntry) - 1);
1456 offset = uio->uio_offset;
1457 if (count < sizeof(struct direntry) ||
1458 (offset & (sizeof(struct direntry) - 1)))
1459 return (EINVAL);
1460 lost = uio->uio_resid - count;
1461 uio->uio_resid = count;
1462
1463 dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
1464
1465 /*
1466 * If they are reading from the root directory then, we simulate
1467 * the . and .. entries since these don't exist in the root
1468 * directory. We also set the offset bias to make up for having to
1469 * simulate these entries. By this I mean that at file offset 64 we
1470 * read the first entry in the root directory that lives on disk.
1471 */
1472 if (dep->de_StartCluster == MSDOSFSROOT
1473 || (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)) {
1474 #if 0
1475 printf("msdosfs_readdir(): going after . or .. in root dir, offset %d\n",
1476 offset);
1477 #endif
1478 bias = 2 * sizeof(struct direntry);
1479 if (offset < bias) {
1480 for (n = (int)offset / sizeof(struct direntry);
1481 n < 2; n++) {
1482 if (FAT32(pmp))
1483 dirbuf.d_fileno = pmp->pm_rootdirblk;
1484 else
1485 dirbuf.d_fileno = 1;
1486 dirbuf.d_type = DT_DIR;
1487 switch (n) {
1488 case 0:
1489 dirbuf.d_namlen = 1;
1490 strlcpy(dirbuf.d_name, ".",
1491 sizeof dirbuf.d_name);
1492 break;
1493 case 1:
1494 dirbuf.d_namlen = 2;
1495 strlcpy(dirbuf.d_name, "..",
1496 sizeof dirbuf.d_name);
1497 break;
1498 }
1499 dirbuf.d_reclen = DIRENT_SIZE(&dirbuf);
1500 dirbuf.d_off = offset +
1501 sizeof(struct direntry);
1502 if (uio->uio_resid < dirbuf.d_reclen)
1503 goto out;
1504 error = uiomove(&dirbuf, dirbuf.d_reclen, uio);
1505 if (error)
1506 goto out;
1507 offset = dirbuf.d_off;
1508 }
1509 }
1510 }
1511
1512 while (uio->uio_resid > 0) {
1513 lbn = de_cluster(pmp, offset - bias);
1514 on = (offset - bias) & pmp->pm_crbomask;
1515 n = min(pmp->pm_bpcluster - on, uio->uio_resid);
1516 diff = dep->de_FileSize - (offset - bias);
1517 if (diff <= 0)
1518 break;
1519 n = min(n, diff);
1520 if ((error = pcbmap(dep, lbn, &bn, &cn, &blsize)) != 0)
1521 break;
1522 error = bread(pmp->pm_devvp, bn, blsize, &bp);
1523 if (error) {
1524 brelse(bp);
1525 return (error);
1526 }
1527 n = min(n, blsize - bp->b_resid);
1528
1529 /*
1530 * Convert from dos directory entries to fs-independent
1531 * directory entries.
1532 */
1533 for (dentp = (struct direntry *)(bp->b_data + on);
1534 (char *)dentp < bp->b_data + on + n;
1535 dentp++, offset += sizeof(struct direntry)) {
1536 #if 0
1537 printf("rd: dentp %08x prev %08x crnt %08x deName %02x attr %02x\n",
1538 dentp, prev, crnt, dentp->deName[0], dentp->deAttributes);
1539 #endif
1540 /*
1541 * If this is an unused entry, we can stop.
1542 */
1543 if (dentp->deName[0] == SLOT_EMPTY) {
1544 brelse(bp);
1545 goto out;
1546 }
1547 /*
1548 * Skip deleted entries.
1549 */
1550 if (dentp->deName[0] == SLOT_DELETED) {
1551 chksum = -1;
1552 wlast = -1;
1553 continue;
1554 }
1555
1556 /*
1557 * Handle Win95 long directory entries
1558 */
1559 if (dentp->deAttributes == ATTR_WIN95) {
1560 struct winentry *wep;
1561 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
1562 continue;
1563 wep = (struct winentry *)dentp;
1564 chksum = win2unixfn(wep, &dirbuf, chksum);
1565 if (wep->weCnt & WIN_LAST)
1566 wlast = offset;
1567 continue;
1568 }
1569
1570 /*
1571 * Skip volume labels
1572 */
1573 if (dentp->deAttributes & ATTR_VOLUME) {
1574 chksum = -1;
1575 wlast = -1;
1576 continue;
1577 }
1578
1579 /*
1580 * This computation of d_fileno must match
1581 * the computation of va_fileid in
1582 * msdosfs_getattr.
1583 */
1584 fileno = getushort(dentp->deStartCluster);
1585 if (FAT32(pmp))
1586 fileno |= getushort(dentp->deHighClust) << 16;
1587
1588 if (dentp->deAttributes & ATTR_DIRECTORY) {
1589 /* Special-case root */
1590 if (fileno == MSDOSFSROOT) {
1591 fileno = FAT32(pmp) ?
1592 pmp->pm_rootdirblk : 1;
1593 }
1594
1595 dirbuf.d_fileno = fileno;
1596 dirbuf.d_type = DT_DIR;
1597 } else {
1598 if (getulong(dentp->deFileSize) == 0) {
1599 uint64_t fileno64;
1600
1601 fileno64 = (cn == MSDOSFSROOT) ?
1602 roottobn(pmp, 0) : cntobn(pmp, cn);
1603
1604 fileno64 *= dirsperblk;
1605 fileno64 += dentp -
1606 (struct direntry *)bp->b_data;
1607
1608 fileno = fileidhash(fileno64);
1609 }
1610
1611 dirbuf.d_fileno = fileno;
1612 dirbuf.d_type = DT_REG;
1613 }
1614
1615 if (chksum != winChksum(dentp->deName))
1616 dirbuf.d_namlen = dos2unixfn(dentp->deName,
1617 (u_char *)dirbuf.d_name,
1618 pmp->pm_flags & MSDOSFSMNT_SHORTNAME);
1619 else
1620 dirbuf.d_name[dirbuf.d_namlen] = 0;
1621 chksum = -1;
1622 dirbuf.d_reclen = DIRENT_SIZE(&dirbuf);
1623 dirbuf.d_off = offset + sizeof(struct direntry);
1624 if (uio->uio_resid < dirbuf.d_reclen) {
1625 brelse(bp);
1626 /* Remember long-name offset. */
1627 if (wlast != -1)
1628 offset = wlast;
1629 goto out;
1630 }
1631 wlast = -1;
1632 error = uiomove(&dirbuf, dirbuf.d_reclen, uio);
1633 if (error) {
1634 brelse(bp);
1635 goto out;
1636 }
1637 }
1638 brelse(bp);
1639 }
1640
1641 out:
1642 uio->uio_offset = offset;
1643 uio->uio_resid += lost;
1644 if (dep->de_FileSize - (offset - bias) <= 0)
1645 *ap->a_eofflag = 1;
1646 else
1647 *ap->a_eofflag = 0;
1648 return (error);
1649 }
1650
1651 /*
1652 * DOS filesystems don't know what symlinks are.
1653 */
1654 int
msdosfs_readlink(void * v)1655 msdosfs_readlink(void *v)
1656 {
1657 #if 0
1658 struct vop_readlink_args /* {
1659 struct vnode *a_vp;
1660 struct uio *a_uio;
1661 struct ucred *a_cred;
1662 } */ *ap;
1663 #endif
1664
1665 return (EINVAL);
1666 }
1667
1668 int
msdosfs_lock(void * v)1669 msdosfs_lock(void *v)
1670 {
1671 struct vop_lock_args *ap = v;
1672 struct vnode *vp = ap->a_vp;
1673
1674 return rrw_enter(&VTODE(vp)->de_lock, ap->a_flags & LK_RWFLAGS);
1675 }
1676
1677 int
msdosfs_unlock(void * v)1678 msdosfs_unlock(void *v)
1679 {
1680 struct vop_unlock_args *ap = v;
1681 struct vnode *vp = ap->a_vp;
1682
1683 rrw_exit(&VTODE(vp)->de_lock);
1684 return 0;
1685 }
1686
1687 int
msdosfs_islocked(void * v)1688 msdosfs_islocked(void *v)
1689 {
1690 struct vop_islocked_args *ap = v;
1691
1692 return rrw_status(&VTODE(ap->a_vp)->de_lock);
1693 }
1694
1695 /*
1696 * vp - address of vnode file the file
1697 * bn - which cluster we are interested in mapping to a filesystem block number
1698 * vpp - returns the vnode for the block special file holding the filesystem
1699 * containing the file of interest
1700 * bnp - address of where to return the filesystem relative block number
1701 */
1702 int
msdosfs_bmap(void * v)1703 msdosfs_bmap(void *v)
1704 {
1705 struct vop_bmap_args *ap = v;
1706 struct denode *dep = VTODE(ap->a_vp);
1707 uint32_t cn;
1708
1709 if (ap->a_vpp != NULL)
1710 *ap->a_vpp = dep->de_devvp;
1711 if (ap->a_bnp == NULL)
1712 return (0);
1713
1714 cn = ap->a_bn;
1715 if (cn != ap->a_bn)
1716 return (EFBIG);
1717
1718 return (msdosfs_bmaparray(ap->a_vp, cn, ap->a_bnp, ap->a_runp));
1719 }
1720
1721 int
msdosfs_bmaparray(struct vnode * vp,uint32_t cn,daddr_t * bnp,int * runp)1722 msdosfs_bmaparray(struct vnode *vp, uint32_t cn, daddr_t *bnp, int *runp)
1723 {
1724 struct denode *dep = VTODE(vp);
1725 struct msdosfsmount *pmp = dep->de_pmp;
1726 struct mount *mp;
1727 int error, maxrun = 0, run;
1728 daddr_t runbn;
1729
1730 mp = vp->v_mount;
1731
1732 if (runp) {
1733 /*
1734 * XXX
1735 * If MAXBSIZE is the largest transfer the disks can handle,
1736 * we probably want maxrun to be 1 block less so that we
1737 * don't create a block larger than the device can handle.
1738 */
1739 *runp = 0;
1740 maxrun = min(MAXBSIZE / mp->mnt_stat.f_iosize - 1,
1741 pmp->pm_maxcluster - cn);
1742 }
1743
1744 if ((error = pcbmap(dep, cn, bnp, 0, 0)) != 0)
1745 return (error);
1746
1747 for (run = 1; run <= maxrun; run++) {
1748 error = pcbmap(dep, cn + run, &runbn, 0, 0);
1749 if (error != 0 || (runbn != *bnp + de_cn2bn(pmp, run)))
1750 break;
1751 }
1752
1753 if (runp)
1754 *runp = run - 1;
1755
1756 return (0);
1757 }
1758
1759 int
msdosfs_strategy(void * v)1760 msdosfs_strategy(void *v)
1761 {
1762 struct vop_strategy_args *ap = v;
1763 struct buf *bp = ap->a_bp;
1764 struct denode *dep = VTODE(bp->b_vp);
1765 struct vnode *vp;
1766 int error = 0;
1767 int s;
1768
1769 if (bp->b_vp->v_type == VBLK || bp->b_vp->v_type == VCHR)
1770 panic("msdosfs_strategy: spec");
1771 /*
1772 * If we don't already know the filesystem relative block number
1773 * then get it using pcbmap(). If pcbmap() returns the block
1774 * number as -1 then we've got a hole in the file. DOS filesystems
1775 * don't allow files with holes, so we shouldn't ever see this.
1776 */
1777 if (bp->b_blkno == bp->b_lblkno) {
1778 error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno, 0, 0);
1779 if (error)
1780 bp->b_blkno = -1;
1781 if (bp->b_blkno == -1)
1782 clrbuf(bp);
1783 }
1784 if (bp->b_blkno == -1) {
1785 s = splbio();
1786 biodone(bp);
1787 splx(s);
1788 return (error);
1789 }
1790
1791 /*
1792 * Read/write the block from/to the disk that contains the desired
1793 * file block.
1794 */
1795
1796 vp = dep->de_devvp;
1797 bp->b_dev = vp->v_rdev;
1798 VOP_STRATEGY(vp, bp);
1799 return (0);
1800 }
1801
1802 int
msdosfs_print(void * v)1803 msdosfs_print(void *v)
1804 {
1805 #if defined(DEBUG) || defined(DIAGNOSTIC) || defined(VFSLCKDEBUG)
1806 struct vop_print_args *ap = v;
1807 struct denode *dep = VTODE(ap->a_vp);
1808
1809 printf(
1810 "tag VT_MSDOSFS, startcluster %u, dircluster %u, diroffset %u ",
1811 dep->de_StartCluster, dep->de_dirclust, dep->de_diroffset);
1812 printf(" dev %d, %d, %s\n",
1813 major(dep->de_dev), minor(dep->de_dev),
1814 VOP_ISLOCKED(ap->a_vp) ? "(LOCKED)" : "");
1815 #ifdef DIAGNOSTIC
1816 printf("\n");
1817 #endif
1818 #endif
1819
1820 return (0);
1821 }
1822
1823 int
msdosfs_advlock(void * v)1824 msdosfs_advlock(void *v)
1825 {
1826 struct vop_advlock_args *ap = v;
1827 struct denode *dep = VTODE(ap->a_vp);
1828
1829 return (lf_advlock(&dep->de_lockf, dep->de_FileSize, ap->a_id, ap->a_op,
1830 ap->a_fl, ap->a_flags));
1831 }
1832
1833 int
msdosfs_pathconf(void * v)1834 msdosfs_pathconf(void *v)
1835 {
1836 struct vop_pathconf_args *ap = v;
1837 struct msdosfsmount *pmp = VTODE(ap->a_vp)->de_pmp;
1838 int error = 0;
1839
1840 switch (ap->a_name) {
1841 case _PC_LINK_MAX:
1842 *ap->a_retval = 1;
1843 break;
1844 case _PC_NAME_MAX:
1845 *ap->a_retval = pmp->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12;
1846 break;
1847 case _PC_CHOWN_RESTRICTED:
1848 *ap->a_retval = 1;
1849 break;
1850 case _PC_NO_TRUNC:
1851 *ap->a_retval = 0;
1852 break;
1853 case _PC_TIMESTAMP_RESOLUTION:
1854 *ap->a_retval = 2000000000; /* 2 billion nanoseconds */
1855 break;
1856 default:
1857 error = EINVAL;
1858 break;
1859 }
1860
1861 return (error);
1862 }
1863
1864 /*
1865 * Thomas Wang's hash function, severely hacked to always set the high
1866 * bit on the number it returns (so no longer a proper hash function).
1867 */
1868 static uint32_t
fileidhash(uint64_t fileid)1869 fileidhash(uint64_t fileid)
1870 {
1871 uint64_t c1 = 0x6e5ea73858134343LL;
1872 uint64_t c2 = 0xb34e8f99a2ec9ef5LL;
1873
1874 /*
1875 * We now have the original fileid value, as 64-bit value.
1876 * We need to reduce it to 32-bits, with the top bit set.
1877 */
1878 fileid ^= ((c1 ^ fileid) >> 32);
1879 fileid *= c1;
1880 fileid ^= ((c2 ^ fileid) >> 31);
1881 fileid *= c2;
1882 fileid ^= ((c1 ^ fileid) >> 32);
1883
1884 return (uint32_t)(fileid | 0x80000000);
1885 }
1886
1887 /* Global vfs data structures for msdosfs */
1888 const struct vops msdosfs_vops = {
1889 .vop_lookup = msdosfs_lookup,
1890 .vop_create = msdosfs_create,
1891 .vop_mknod = msdosfs_mknod,
1892 .vop_open = msdosfs_open,
1893 .vop_close = msdosfs_close,
1894 .vop_access = msdosfs_access,
1895 .vop_getattr = msdosfs_getattr,
1896 .vop_setattr = msdosfs_setattr,
1897 .vop_read = msdosfs_read,
1898 .vop_write = msdosfs_write,
1899 .vop_ioctl = msdosfs_ioctl,
1900 .vop_kqfilter = msdosfs_kqfilter,
1901 .vop_fsync = msdosfs_fsync,
1902 .vop_remove = msdosfs_remove,
1903 .vop_link = msdosfs_link,
1904 .vop_rename = msdosfs_rename,
1905 .vop_mkdir = msdosfs_mkdir,
1906 .vop_rmdir = msdosfs_rmdir,
1907 .vop_symlink = msdosfs_symlink,
1908 .vop_readdir = msdosfs_readdir,
1909 .vop_readlink = msdosfs_readlink,
1910 .vop_abortop = vop_generic_abortop,
1911 .vop_inactive = msdosfs_inactive,
1912 .vop_reclaim = msdosfs_reclaim,
1913 .vop_lock = msdosfs_lock,
1914 .vop_unlock = msdosfs_unlock,
1915 .vop_bmap = msdosfs_bmap,
1916 .vop_strategy = msdosfs_strategy,
1917 .vop_print = msdosfs_print,
1918 .vop_islocked = msdosfs_islocked,
1919 .vop_pathconf = msdosfs_pathconf,
1920 .vop_advlock = msdosfs_advlock,
1921 .vop_bwrite = vop_generic_bwrite,
1922 .vop_revoke = vop_generic_revoke,
1923 };
1924
1925 const struct filterops msdosfsread_filtops = {
1926 .f_flags = FILTEROP_ISFD,
1927 .f_attach = NULL,
1928 .f_detach = filt_msdosfsdetach,
1929 .f_event = filt_msdosfsread,
1930 };
1931
1932 const struct filterops msdosfswrite_filtops = {
1933 .f_flags = FILTEROP_ISFD,
1934 .f_attach = NULL,
1935 .f_detach = filt_msdosfsdetach,
1936 .f_event = filt_msdosfswrite,
1937 };
1938
1939 const struct filterops msdosfsvnode_filtops = {
1940 .f_flags = FILTEROP_ISFD,
1941 .f_attach = NULL,
1942 .f_detach = filt_msdosfsdetach,
1943 .f_event = filt_msdosfsvnode,
1944 };
1945
1946 int
msdosfs_kqfilter(void * v)1947 msdosfs_kqfilter(void *v)
1948 {
1949 struct vop_kqfilter_args *ap = v;
1950 struct vnode *vp = ap->a_vp;
1951 struct knote *kn = ap->a_kn;
1952
1953 switch (kn->kn_filter) {
1954 case EVFILT_READ:
1955 kn->kn_fop = &msdosfsread_filtops;
1956 break;
1957 case EVFILT_WRITE:
1958 kn->kn_fop = &msdosfswrite_filtops;
1959 break;
1960 case EVFILT_VNODE:
1961 kn->kn_fop = &msdosfsvnode_filtops;
1962 break;
1963 default:
1964 return (EINVAL);
1965 }
1966
1967 kn->kn_hook = (caddr_t)vp;
1968
1969 klist_insert_locked(&vp->v_klist, kn);
1970
1971 return (0);
1972 }
1973
1974 void
filt_msdosfsdetach(struct knote * kn)1975 filt_msdosfsdetach(struct knote *kn)
1976 {
1977 struct vnode *vp = (struct vnode *)kn->kn_hook;
1978
1979 klist_remove_locked(&vp->v_klist, kn);
1980 }
1981
1982 int
filt_msdosfsread(struct knote * kn,long hint)1983 filt_msdosfsread(struct knote *kn, long hint)
1984 {
1985 struct vnode *vp = (struct vnode *)kn->kn_hook;
1986 struct denode *dep = VTODE(vp);
1987
1988 /*
1989 * filesystem is gone, so set the EOF flag and schedule
1990 * the knote for deletion.
1991 */
1992 if (hint == NOTE_REVOKE) {
1993 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
1994 return (1);
1995 }
1996
1997 kn->kn_data = dep->de_FileSize - foffset(kn->kn_fp);
1998 if (kn->kn_data == 0 && kn->kn_sfflags & NOTE_EOF) {
1999 kn->kn_fflags |= NOTE_EOF;
2000 return (1);
2001 }
2002
2003 if (kn->kn_flags & (__EV_POLL | __EV_SELECT))
2004 return (1);
2005
2006 return (kn->kn_data != 0);
2007 }
2008
2009 int
filt_msdosfswrite(struct knote * kn,long hint)2010 filt_msdosfswrite(struct knote *kn, long hint)
2011 {
2012 /*
2013 * filesystem is gone, so set the EOF flag and schedule
2014 * the knote for deletion.
2015 */
2016 if (hint == NOTE_REVOKE) {
2017 kn->kn_flags |= (EV_EOF | EV_ONESHOT);
2018 return (1);
2019 }
2020
2021 kn->kn_data = 0;
2022 return (1);
2023 }
2024
2025 int
filt_msdosfsvnode(struct knote * kn,long hint)2026 filt_msdosfsvnode(struct knote *kn, long hint)
2027 {
2028 if (kn->kn_sfflags & hint)
2029 kn->kn_fflags |= hint;
2030 if (hint == NOTE_REVOKE) {
2031 kn->kn_flags |= EV_EOF;
2032 return (1);
2033 }
2034 return (kn->kn_fflags != 0);
2035 }
2036