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 72 static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part"); 73 74 static int 75 de_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 * lkflags - locking flags (LK_NOWAIT) 96 * depp - returns the address of the gotten denode. 97 */ 98 int 99 deget(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset, 100 int lkflags, struct denode **depp) 101 { 102 int error; 103 uint64_t inode; 104 struct mount *mntp = pmp->pm_mountp; 105 struct direntry *direntptr; 106 struct denode *ldep; 107 struct vnode *nvp, *xvp; 108 struct buf *bp; 109 110 #ifdef MSDOSFS_DEBUG 111 printf("deget(pmp %p, dirclust %lu, diroffset %lx, flags %#x, " 112 "depp %p)\n", 113 pmp, dirclust, diroffset, flags, depp); 114 #endif 115 MPASS((lkflags & LK_TYPE_MASK) == LK_EXCLUSIVE); 116 117 /* 118 * On FAT32 filesystems, root is a (more or less) normal 119 * directory 120 */ 121 if (FAT32(pmp) && dirclust == MSDOSFSROOT) 122 dirclust = pmp->pm_rootdirblk; 123 124 /* 125 * See if the denode is in the denode cache. Use the location of 126 * the directory entry to compute the hash value. For subdir use 127 * address of "." entry. For root dir (if not FAT32) use cluster 128 * MSDOSFSROOT, offset MSDOSFSROOT_OFS 129 * 130 * NOTE: de_vncmpf will explicitly skip any denodes that do not have 131 * a de_refcnt > 0. This insures that that we do not attempt to use 132 * a denode that represents an unlinked but still open file. 133 * These files are not to be accessible even when the directory 134 * entry that represented the file happens to be reused while the 135 * deleted file is still open. 136 */ 137 inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset; 138 139 error = vfs_hash_get(mntp, inode, lkflags, curthread, &nvp, 140 de_vncmpf, &inode); 141 if (error) 142 return (error); 143 if (nvp != NULL) { 144 *depp = VTODE(nvp); 145 if ((*depp)->de_dirclust != dirclust) { 146 printf("%s: wrong dir cluster %lu %lu\n", 147 pmp->pm_mountp->mnt_stat.f_mntonname, 148 (*depp)->de_dirclust, dirclust); 149 goto badoff; 150 } 151 if ((*depp)->de_diroffset != diroffset) { 152 printf("%s: wrong dir offset %lu %lu\n", 153 pmp->pm_mountp->mnt_stat.f_mntonname, 154 (*depp)->de_diroffset, diroffset); 155 goto badoff; 156 } 157 return (0); 158 badoff: 159 vgone(nvp); 160 vput(nvp); 161 return (EBADF); 162 } 163 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO); 164 165 /* 166 * Directory entry was not in cache, have to create a vnode and 167 * copy it from the passed disk buffer. 168 */ 169 /* getnewvnode() does a VREF() on the vnode */ 170 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp); 171 if (error) { 172 *depp = NULL; 173 free(ldep, M_MSDOSFSNODE); 174 return error; 175 } 176 nvp->v_data = ldep; 177 ldep->de_vnode = nvp; 178 ldep->de_flag = 0; 179 ldep->de_dirclust = dirclust; 180 ldep->de_diroffset = diroffset; 181 ldep->de_inode = inode; 182 cluster_init_vn(&ldep->de_clusterw); 183 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL); 184 VN_LOCK_AREC(nvp); /* for doscheckpath */ 185 fc_purge(ldep, 0); /* init the FAT cache for this denode */ 186 error = insmntque(nvp, mntp); 187 if (error != 0) { 188 free(ldep, M_MSDOSFSNODE); 189 *depp = NULL; 190 return (error); 191 } 192 error = vfs_hash_insert(nvp, inode, lkflags, curthread, &xvp, 193 de_vncmpf, &inode); 194 if (error) { 195 *depp = NULL; 196 return (error); 197 } 198 if (xvp != NULL) { 199 *depp = xvp->v_data; 200 return (0); 201 } 202 203 ldep->de_pmp = pmp; 204 ldep->de_refcnt = 1; 205 /* 206 * Copy the directory entry into the denode area of the vnode. 207 */ 208 if ((dirclust == MSDOSFSROOT 209 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) 210 && diroffset == MSDOSFSROOT_OFS) { 211 /* 212 * Directory entry for the root directory. There isn't one, 213 * so we manufacture one. We should probably rummage 214 * through the root directory and find a label entry (if it 215 * exists), and then use the time and date from that entry 216 * as the time and date for the root denode. 217 */ 218 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */ 219 220 ldep->de_Attributes = ATTR_DIRECTORY; 221 ldep->de_LowerCase = 0; 222 if (FAT32(pmp)) 223 ldep->de_StartCluster = pmp->pm_rootdirblk; 224 /* de_FileSize will be filled in further down */ 225 else { 226 ldep->de_StartCluster = MSDOSFSROOT; 227 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE; 228 } 229 /* 230 * fill in time and date so that fattime2timespec() doesn't 231 * spit up when called from msdosfs_getattr() with root 232 * denode 233 */ 234 ldep->de_CHun = 0; 235 ldep->de_CTime = 0x0000; /* 00:00:00 */ 236 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 237 | (1 << DD_DAY_SHIFT); 238 /* Jan 1, 1980 */ 239 ldep->de_ADate = ldep->de_CDate; 240 ldep->de_MTime = ldep->de_CTime; 241 ldep->de_MDate = ldep->de_CDate; 242 /* leave the other fields as garbage */ 243 } else { 244 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 245 if (error) { 246 /* 247 * The denode does not contain anything useful, so 248 * it would be wrong to leave it on its hash chain. 249 * Arrange for vput() to just forget about it. 250 */ 251 ldep->de_Name[0] = SLOT_DELETED; 252 vgone(nvp); 253 vput(nvp); 254 *depp = NULL; 255 return (error); 256 } 257 (void)DE_INTERNALIZE(ldep, direntptr); 258 brelse(bp); 259 } 260 261 /* 262 * Fill in a few fields of the vnode and finish filling in the 263 * denode. Then return the address of the found denode. 264 */ 265 if (ldep->de_Attributes & ATTR_DIRECTORY) { 266 /* 267 * Since DOS directory entries that describe directories 268 * have 0 in the filesize field, we take this opportunity 269 * to find out the length of the directory and plug it into 270 * the denode structure. 271 */ 272 u_long size; 273 274 /* 275 * XXX it sometimes happens that the "." entry has cluster 276 * number 0 when it shouldn't. Use the actual cluster number 277 * instead of what is written in directory entry. 278 */ 279 if (diroffset == 0 && ldep->de_StartCluster != dirclust) { 280 #ifdef MSDOSFS_DEBUG 281 printf("deget(): \".\" entry at clust %lu != %lu\n", 282 dirclust, ldep->de_StartCluster); 283 #endif 284 ldep->de_StartCluster = dirclust; 285 } 286 287 nvp->v_type = VDIR; 288 if (ldep->de_StartCluster != MSDOSFSROOT) { 289 error = pcbmap(ldep, 0xffff, 0, &size, 0); 290 if (error == E2BIG) { 291 ldep->de_FileSize = de_cn2off(pmp, size); 292 error = 0; 293 } else { 294 #ifdef MSDOSFS_DEBUG 295 printf("deget(): pcbmap returned %d\n", error); 296 #endif 297 } 298 } 299 } else 300 nvp->v_type = VREG; 301 ldep->de_modrev = init_va_filerev(); 302 *depp = ldep; 303 return (0); 304 } 305 306 int 307 deupdat(struct denode *dep, int waitfor) 308 { 309 struct direntry dir; 310 struct timespec ts; 311 struct buf *bp; 312 struct direntry *dirp; 313 int error; 314 315 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) { 316 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS | 317 DE_MODIFIED); 318 return (0); 319 } 320 vfs_timestamp(&ts); 321 DETIMES(dep, &ts, &ts, &ts); 322 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0) 323 return (0); 324 dep->de_flag &= ~DE_MODIFIED; 325 if (DETOV(dep)->v_vflag & VV_ROOT) 326 return (EINVAL); 327 if (dep->de_refcnt <= 0) 328 return (0); 329 error = readde(dep, &bp, &dirp); 330 if (error) 331 return (error); 332 DE_EXTERNALIZE(&dir, dep); 333 if (bcmp(dirp, &dir, sizeof(dir)) == 0) { 334 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) { 335 brelse(bp); 336 return (0); 337 } 338 } else 339 *dirp = dir; 340 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) 341 bp->b_flags |= B_CLUSTEROK; 342 if (waitfor) 343 error = bwrite(bp); 344 else if (vm_page_count_severe() || buf_dirty_count_severe()) 345 bawrite(bp); 346 else 347 bdwrite(bp); 348 return (error); 349 } 350 351 /* 352 * Truncate the file described by dep to the length specified by length. 353 */ 354 int 355 detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred) 356 { 357 int error; 358 int allerror; 359 u_long eofentry; 360 u_long chaintofree; 361 daddr_t bn; 362 int boff; 363 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 364 struct buf *bp; 365 struct msdosfsmount *pmp = dep->de_pmp; 366 367 #ifdef MSDOSFS_DEBUG 368 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags); 369 #endif 370 371 /* 372 * Disallow attempts to truncate the root directory since it is of 373 * fixed size. That's just the way dos filesystems are. We use 374 * the VROOT bit in the vnode because checking for the directory 375 * bit and a startcluster of 0 in the denode is not adequate to 376 * recognize the root directory at this point in a file or 377 * directory's life. 378 */ 379 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) { 380 #ifdef MSDOSFS_DEBUG 381 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 382 dep->de_dirclust, dep->de_diroffset); 383 #endif 384 return (EINVAL); 385 } 386 387 if (dep->de_FileSize < length) { 388 vnode_pager_setsize(DETOV(dep), length); 389 return deextend(dep, length, cred); 390 } 391 392 /* 393 * If the desired length is 0 then remember the starting cluster of 394 * the file and set the StartCluster field in the directory entry 395 * to 0. If the desired length is not zero, then get the number of 396 * the last cluster in the shortened file. Then get the number of 397 * the first cluster in the part of the file that is to be freed. 398 * Then set the next cluster pointer in the last cluster of the 399 * file to CLUST_EOFE. 400 */ 401 if (length == 0) { 402 chaintofree = dep->de_StartCluster; 403 dep->de_StartCluster = 0; 404 eofentry = ~0; 405 } else { 406 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 407 &eofentry, 0); 408 if (error) { 409 #ifdef MSDOSFS_DEBUG 410 printf("detrunc(): pcbmap fails %d\n", error); 411 #endif 412 return (error); 413 } 414 } 415 416 fc_purge(dep, de_clcount(pmp, length)); 417 418 /* 419 * If the new length is not a multiple of the cluster size then we 420 * must zero the tail end of the new last cluster in case it 421 * becomes part of the file again because of a seek. 422 */ 423 if ((boff = length & pmp->pm_crbomask) != 0) { 424 if (isadir) { 425 bn = cntobn(pmp, eofentry); 426 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 427 NOCRED, &bp); 428 } else { 429 error = bread(DETOV(dep), de_cluster(pmp, length), 430 pmp->pm_bpcluster, cred, &bp); 431 } 432 if (error) { 433 #ifdef MSDOSFS_DEBUG 434 printf("detrunc(): bread fails %d\n", error); 435 #endif 436 return (error); 437 } 438 memset(bp->b_data + boff, 0, pmp->pm_bpcluster - boff); 439 if ((flags & IO_SYNC) != 0) 440 bwrite(bp); 441 else 442 bdwrite(bp); 443 } 444 445 /* 446 * Write out the updated directory entry. Even if the update fails 447 * we free the trailing clusters. 448 */ 449 dep->de_FileSize = length; 450 if (!isadir) 451 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 452 allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster); 453 #ifdef MSDOSFS_DEBUG 454 if (allerror) 455 printf("detrunc(): vtruncbuf error %d\n", allerror); 456 #endif 457 error = deupdat(dep, !DOINGASYNC((DETOV(dep)))); 458 if (error != 0 && allerror == 0) 459 allerror = error; 460 #ifdef MSDOSFS_DEBUG 461 printf("detrunc(): allerror %d, eofentry %lu\n", 462 allerror, eofentry); 463 #endif 464 465 /* 466 * If we need to break the cluster chain for the file then do it 467 * now. 468 */ 469 if (eofentry != ~0) { 470 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 471 &chaintofree, CLUST_EOFE); 472 if (error) { 473 #ifdef MSDOSFS_DEBUG 474 printf("detrunc(): fatentry errors %d\n", error); 475 #endif 476 return (error); 477 } 478 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 479 eofentry); 480 } 481 482 /* 483 * Now free the clusters removed from the file because of the 484 * truncation. 485 */ 486 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 487 freeclusterchain(pmp, chaintofree); 488 489 return (allerror); 490 } 491 492 /* 493 * Extend the file described by dep to length specified by length. 494 */ 495 int 496 deextend(struct denode *dep, u_long length, struct ucred *cred) 497 { 498 struct msdosfsmount *pmp = dep->de_pmp; 499 u_long count; 500 int error; 501 502 /* 503 * The root of a DOS filesystem cannot be extended. 504 */ 505 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) 506 return (EINVAL); 507 508 /* 509 * Directories cannot be extended. 510 */ 511 if (dep->de_Attributes & ATTR_DIRECTORY) 512 return (EISDIR); 513 514 if (length <= dep->de_FileSize) 515 panic("deextend: file too large"); 516 517 /* 518 * Compute the number of clusters to allocate. 519 */ 520 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 521 if (count > 0) { 522 if (count > pmp->pm_freeclustercount) 523 return (ENOSPC); 524 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 525 if (error) { 526 /* truncate the added clusters away again */ 527 (void) detrunc(dep, dep->de_FileSize, 0, cred); 528 return (error); 529 } 530 } 531 dep->de_FileSize = length; 532 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 533 return (deupdat(dep, !DOINGASYNC(DETOV(dep)))); 534 } 535 536 /* 537 * Move a denode to its correct hash queue after the file it represents has 538 * been moved to a new directory. 539 */ 540 void 541 reinsert(struct denode *dep) 542 { 543 struct vnode *vp; 544 545 /* 546 * Fix up the denode cache. If the denode is for a directory, 547 * there is nothing to do since the hash is based on the starting 548 * cluster of the directory file and that hasn't changed. If for a 549 * file the hash is based on the location of the directory entry, 550 * so we must remove it from the cache and re-enter it with the 551 * hash based on the new location of the directory entry. 552 */ 553 #if 0 554 if (dep->de_Attributes & ATTR_DIRECTORY) 555 return; 556 #endif 557 vp = DETOV(dep); 558 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust + 559 dep->de_diroffset; 560 vfs_hash_rehash(vp, dep->de_inode); 561 } 562 563 int 564 msdosfs_reclaim(struct vop_reclaim_args *ap) 565 { 566 struct vnode *vp = ap->a_vp; 567 struct denode *dep = VTODE(vp); 568 569 #ifdef MSDOSFS_DEBUG 570 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n", 571 dep, dep->de_Name, dep->de_refcnt); 572 #endif 573 574 /* 575 * Remove the denode from its hash chain. 576 */ 577 vfs_hash_remove(vp); 578 /* 579 * Purge old data structures associated with the denode. 580 */ 581 #if 0 /* XXX */ 582 dep->de_flag = 0; 583 #endif 584 free(dep, M_MSDOSFSNODE); 585 vp->v_data = NULL; 586 587 return (0); 588 } 589 590 int 591 msdosfs_inactive(struct vop_inactive_args *ap) 592 { 593 struct vnode *vp = ap->a_vp; 594 struct denode *dep = VTODE(vp); 595 int error = 0; 596 597 #ifdef MSDOSFS_DEBUG 598 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]); 599 #endif 600 601 /* 602 * Ignore denodes related to stale file handles. 603 */ 604 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 605 goto out; 606 607 /* 608 * If the file has been deleted and it is on a read/write 609 * filesystem, then truncate the file, and mark the directory slot 610 * as empty. (This may not be necessary for the dos filesystem.) 611 */ 612 #ifdef MSDOSFS_DEBUG 613 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %llx, MNT_RDONLY %llx\n", 614 dep, dep->de_refcnt, (unsigned long long)vp->v_mount->mnt_flag, 615 (unsigned long long)MNT_RDONLY); 616 #endif 617 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 618 error = detrunc(dep, (u_long) 0, 0, NOCRED); 619 dep->de_flag |= DE_UPDATE; 620 dep->de_Name[0] = SLOT_DELETED; 621 } 622 deupdat(dep, 0); 623 624 out: 625 /* 626 * If we are done with the denode, reclaim it 627 * so that it can be reused immediately. 628 */ 629 #ifdef MSDOSFS_DEBUG 630 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 631 vrefcnt(vp), dep->de_Name[0]); 632 #endif 633 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 634 vrecycle(vp); 635 return (error); 636 } 637