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 msdosfs_integrity_error(pmp); 162 return (EBADF); 163 } 164 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO); 165 166 /* 167 * Directory entry was not in cache, have to create a vnode and 168 * copy it from the passed disk buffer. 169 */ 170 /* getnewvnode() does a VREF() on the vnode */ 171 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp); 172 if (error) { 173 *depp = NULL; 174 free(ldep, M_MSDOSFSNODE); 175 return error; 176 } 177 nvp->v_data = ldep; 178 ldep->de_vnode = nvp; 179 ldep->de_flag = 0; 180 ldep->de_dirclust = dirclust; 181 ldep->de_diroffset = diroffset; 182 ldep->de_inode = inode; 183 cluster_init_vn(&ldep->de_clusterw); 184 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL); 185 VN_LOCK_AREC(nvp); /* for doscheckpath */ 186 fc_purge(ldep, 0); /* init the FAT cache for this denode */ 187 error = insmntque(nvp, mntp); 188 if (error != 0) { 189 free(ldep, M_MSDOSFSNODE); 190 *depp = NULL; 191 return (error); 192 } 193 error = vfs_hash_insert(nvp, inode, lkflags, curthread, &xvp, 194 de_vncmpf, &inode); 195 if (error) { 196 *depp = NULL; 197 return (error); 198 } 199 if (xvp != NULL) { 200 *depp = xvp->v_data; 201 return (0); 202 } 203 204 ldep->de_pmp = pmp; 205 ldep->de_refcnt = 1; 206 /* 207 * Copy the directory entry into the denode area of the vnode. 208 */ 209 if ((dirclust == MSDOSFSROOT || 210 (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) && 211 diroffset == MSDOSFSROOT_OFS) { 212 /* 213 * Directory entry for the root directory. There isn't one, 214 * so we manufacture one. We should probably rummage 215 * through the root directory and find a label entry (if it 216 * exists), and then use the time and date from that entry 217 * as the time and date for the root denode. 218 */ 219 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */ 220 221 ldep->de_Attributes = ATTR_DIRECTORY; 222 ldep->de_LowerCase = 0; 223 if (FAT32(pmp)) 224 ldep->de_StartCluster = pmp->pm_rootdirblk; 225 /* de_FileSize will be filled in further down */ 226 else { 227 ldep->de_StartCluster = MSDOSFSROOT; 228 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE; 229 } 230 /* 231 * fill in time and date so that fattime2timespec() doesn't 232 * spit up when called from msdosfs_getattr() with root 233 * denode 234 */ 235 ldep->de_CHun = 0; 236 ldep->de_CTime = 0x0000; /* 00:00:00 */ 237 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 238 | (1 << DD_DAY_SHIFT); 239 /* Jan 1, 1980 */ 240 ldep->de_ADate = ldep->de_CDate; 241 ldep->de_MTime = ldep->de_CTime; 242 ldep->de_MDate = ldep->de_CDate; 243 /* leave the other fields as garbage */ 244 } else { 245 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 246 if (error) { 247 /* 248 * The denode does not contain anything useful, so 249 * it would be wrong to leave it on its hash chain. 250 * Arrange for vput() to just forget about it. 251 */ 252 ldep->de_Name[0] = SLOT_DELETED; 253 vgone(nvp); 254 vput(nvp); 255 *depp = NULL; 256 return (error); 257 } 258 (void)DE_INTERNALIZE(ldep, direntptr); 259 brelse(bp); 260 } 261 262 /* 263 * Fill in a few fields of the vnode and finish filling in the 264 * denode. Then return the address of the found denode. 265 */ 266 if (ldep->de_Attributes & ATTR_DIRECTORY) { 267 /* 268 * Since DOS directory entries that describe directories 269 * have 0 in the filesize field, we take this opportunity 270 * to find out the length of the directory and plug it into 271 * the denode structure. 272 */ 273 u_long size; 274 275 /* 276 * XXX it sometimes happens that the "." entry has cluster 277 * number 0 when it shouldn't. Use the actual cluster number 278 * instead of what is written in directory entry. 279 */ 280 if (diroffset == 0 && ldep->de_StartCluster != dirclust) { 281 #ifdef MSDOSFS_DEBUG 282 printf("deget(): \".\" entry at clust %lu != %lu\n", 283 dirclust, ldep->de_StartCluster); 284 #endif 285 ldep->de_StartCluster = dirclust; 286 } 287 288 nvp->v_type = VDIR; 289 if (ldep->de_StartCluster != MSDOSFSROOT) { 290 error = pcbmap(ldep, 0xffff, 0, &size, 0); 291 if (error == E2BIG) { 292 ldep->de_FileSize = de_cn2off(pmp, size); 293 error = 0; 294 } else { 295 #ifdef MSDOSFS_DEBUG 296 printf("deget(): pcbmap returned %d\n", error); 297 #endif 298 } 299 } 300 } else 301 nvp->v_type = VREG; 302 ldep->de_modrev = init_va_filerev(); 303 *depp = ldep; 304 return (0); 305 } 306 307 int 308 deupdat(struct denode *dep, int waitfor) 309 { 310 struct direntry dir; 311 struct timespec ts; 312 struct buf *bp; 313 struct direntry *dirp; 314 int error; 315 316 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) { 317 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS | 318 DE_MODIFIED); 319 return (0); 320 } 321 vfs_timestamp(&ts); 322 DETIMES(dep, &ts, &ts, &ts); 323 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0) 324 return (0); 325 dep->de_flag &= ~DE_MODIFIED; 326 if (DETOV(dep)->v_vflag & VV_ROOT) 327 return (EINVAL); 328 if (dep->de_refcnt <= 0) 329 return (0); 330 error = readde(dep, &bp, &dirp); 331 if (error) 332 return (error); 333 DE_EXTERNALIZE(&dir, dep); 334 if (bcmp(dirp, &dir, sizeof(dir)) == 0) { 335 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) { 336 brelse(bp); 337 return (0); 338 } 339 } else 340 *dirp = dir; 341 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) 342 bp->b_flags |= B_CLUSTEROK; 343 if (waitfor) 344 error = bwrite(bp); 345 else if (vm_page_count_severe() || buf_dirty_count_severe()) 346 bawrite(bp); 347 else 348 bdwrite(bp); 349 return (error); 350 } 351 352 /* 353 * Truncate the file described by dep to the length specified by length. 354 */ 355 int 356 detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred) 357 { 358 int error; 359 int allerror; 360 u_long eofentry; 361 u_long chaintofree; 362 daddr_t bn; 363 int boff; 364 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 365 struct buf *bp; 366 struct msdosfsmount *pmp = dep->de_pmp; 367 368 #ifdef MSDOSFS_DEBUG 369 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags); 370 #endif 371 372 /* 373 * Disallow attempts to truncate the root directory since it is of 374 * fixed size. That's just the way dos filesystems are. We use 375 * the VROOT bit in the vnode because checking for the directory 376 * bit and a startcluster of 0 in the denode is not adequate to 377 * recognize the root directory at this point in a file or 378 * directory's life. 379 */ 380 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) { 381 #ifdef MSDOSFS_DEBUG 382 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 383 dep->de_dirclust, dep->de_diroffset); 384 #endif 385 return (EINVAL); 386 } 387 388 if (dep->de_FileSize < length) { 389 vnode_pager_setsize(DETOV(dep), length); 390 return (deextend(dep, length, cred)); 391 } 392 393 /* 394 * If the desired length is 0 then remember the starting cluster of 395 * the file and set the StartCluster field in the directory entry 396 * to 0. If the desired length is not zero, then get the number of 397 * the last cluster in the shortened file. Then get the number of 398 * the first cluster in the part of the file that is to be freed. 399 * Then set the next cluster pointer in the last cluster of the 400 * file to CLUST_EOFE. 401 */ 402 if (length == 0) { 403 chaintofree = dep->de_StartCluster; 404 dep->de_StartCluster = 0; 405 eofentry = ~0; 406 } else { 407 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 408 &eofentry, 0); 409 if (error) { 410 #ifdef MSDOSFS_DEBUG 411 printf("detrunc(): pcbmap fails %d\n", error); 412 #endif 413 return (error); 414 } 415 } 416 417 fc_purge(dep, de_clcount(pmp, length)); 418 419 /* 420 * If the new length is not a multiple of the cluster size then we 421 * must zero the tail end of the new last cluster in case it 422 * becomes part of the file again because of a seek. 423 */ 424 if ((boff = length & pmp->pm_crbomask) != 0) { 425 if (isadir) { 426 bn = cntobn(pmp, eofentry); 427 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 428 NOCRED, &bp); 429 } else { 430 error = bread(DETOV(dep), de_cluster(pmp, length), 431 pmp->pm_bpcluster, cred, &bp); 432 } 433 if (error) { 434 #ifdef MSDOSFS_DEBUG 435 printf("detrunc(): bread fails %d\n", error); 436 #endif 437 return (error); 438 } 439 memset(bp->b_data + boff, 0, pmp->pm_bpcluster - boff); 440 if ((flags & IO_SYNC) != 0) 441 bwrite(bp); 442 else 443 bdwrite(bp); 444 } 445 446 /* 447 * Write out the updated directory entry. Even if the update fails 448 * we free the trailing clusters. 449 */ 450 dep->de_FileSize = length; 451 if (!isadir) 452 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 453 allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster); 454 #ifdef MSDOSFS_DEBUG 455 if (allerror) 456 printf("detrunc(): vtruncbuf error %d\n", allerror); 457 #endif 458 error = deupdat(dep, !DOINGASYNC((DETOV(dep)))); 459 if (error != 0 && allerror == 0) 460 allerror = error; 461 #ifdef MSDOSFS_DEBUG 462 printf("detrunc(): allerror %d, eofentry %lu\n", 463 allerror, eofentry); 464 #endif 465 466 /* 467 * If we need to break the cluster chain for the file then do it 468 * now. 469 */ 470 if (eofentry != ~0) { 471 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 472 &chaintofree, CLUST_EOFE); 473 if (error) { 474 #ifdef MSDOSFS_DEBUG 475 printf("detrunc(): fatentry errors %d\n", error); 476 #endif 477 return (error); 478 } 479 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 480 eofentry); 481 } 482 483 /* 484 * Now free the clusters removed from the file because of the 485 * truncation. 486 */ 487 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 488 freeclusterchain(pmp, chaintofree); 489 490 return (allerror); 491 } 492 493 /* 494 * Extend the file described by dep to length specified by length. 495 */ 496 int 497 deextend(struct denode *dep, u_long length, struct ucred *cred) 498 { 499 struct msdosfsmount *pmp = dep->de_pmp; 500 u_long count; 501 int error; 502 503 /* 504 * The root of a DOS filesystem cannot be extended. 505 */ 506 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) 507 return (EINVAL); 508 509 /* 510 * Directories cannot be extended. 511 */ 512 if (dep->de_Attributes & ATTR_DIRECTORY) 513 return (EISDIR); 514 515 if (length <= dep->de_FileSize) 516 panic("deextend: file too large"); 517 518 /* 519 * Compute the number of clusters to allocate. 520 */ 521 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 522 if (count > 0) { 523 if (count > pmp->pm_freeclustercount) 524 return (ENOSPC); 525 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 526 if (error) { 527 /* truncate the added clusters away again */ 528 (void) detrunc(dep, dep->de_FileSize, 0, cred); 529 return (error); 530 } 531 } 532 dep->de_FileSize = length; 533 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 534 return (deupdat(dep, !DOINGASYNC(DETOV(dep)))); 535 } 536 537 /* 538 * Move a denode to its correct hash queue after the file it represents has 539 * been moved to a new directory. 540 */ 541 void 542 reinsert(struct denode *dep) 543 { 544 struct vnode *vp; 545 546 /* 547 * Fix up the denode cache. If the denode is for a directory, 548 * there is nothing to do since the hash is based on the starting 549 * cluster of the directory file and that hasn't changed. If for a 550 * file the hash is based on the location of the directory entry, 551 * so we must remove it from the cache and re-enter it with the 552 * hash based on the new location of the directory entry. 553 */ 554 #if 0 555 if (dep->de_Attributes & ATTR_DIRECTORY) 556 return; 557 #endif 558 vp = DETOV(dep); 559 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust + 560 dep->de_diroffset; 561 vfs_hash_rehash(vp, dep->de_inode); 562 } 563 564 int 565 msdosfs_reclaim(struct vop_reclaim_args *ap) 566 { 567 struct vnode *vp = ap->a_vp; 568 struct denode *dep = VTODE(vp); 569 570 #ifdef MSDOSFS_DEBUG 571 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n", 572 dep, dep->de_Name, dep->de_refcnt); 573 #endif 574 575 /* 576 * Remove the denode from its hash chain. 577 */ 578 vfs_hash_remove(vp); 579 /* 580 * Purge old data structures associated with the denode. 581 */ 582 #if 0 /* XXX */ 583 dep->de_flag = 0; 584 #endif 585 free(dep, M_MSDOSFSNODE); 586 vp->v_data = NULL; 587 588 return (0); 589 } 590 591 int 592 msdosfs_inactive(struct vop_inactive_args *ap) 593 { 594 struct vnode *vp = ap->a_vp; 595 struct denode *dep = VTODE(vp); 596 int error = 0; 597 598 #ifdef MSDOSFS_DEBUG 599 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]); 600 #endif 601 602 /* 603 * Ignore denodes related to stale file handles. 604 */ 605 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 606 goto out; 607 608 /* 609 * If the file has been deleted and it is on a read/write 610 * filesystem, then truncate the file, and mark the directory slot 611 * as empty. (This may not be necessary for the dos filesystem.) 612 */ 613 #ifdef MSDOSFS_DEBUG 614 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %llx, MNT_RDONLY %llx\n", 615 dep, dep->de_refcnt, (unsigned long long)vp->v_mount->mnt_flag, 616 (unsigned long long)MNT_RDONLY); 617 #endif 618 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 619 error = detrunc(dep, (u_long) 0, 0, NOCRED); 620 dep->de_flag |= DE_UPDATE; 621 dep->de_Name[0] = SLOT_DELETED; 622 } 623 deupdat(dep, 0); 624 625 out: 626 /* 627 * If we are done with the denode, reclaim it 628 * so that it can be reused immediately. 629 */ 630 #ifdef MSDOSFS_DEBUG 631 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 632 vrefcnt(vp), dep->de_Name[0]); 633 #endif 634 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 635 vrecycle(vp); 636 return (error); 637 } 638