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); 83 } 84 85 /* 86 * If deget() succeeds it returns with the gotten denode locked(). 87 * 88 * pmp - address of msdosfsmount structure of the filesystem containing 89 * the denode of interest. The address of 90 * the msdosfsmount structure are used. 91 * dirclust - which cluster bp contains, if dirclust is 0 (root directory) 92 * diroffset is relative to the beginning of the root directory, 93 * otherwise it is cluster relative. 94 * diroffset - offset past begin of cluster of denode we want 95 * depp - returns the address of the gotten denode. 96 */ 97 int 98 deget(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset, 99 struct denode **depp) 100 { 101 int error; 102 uint64_t inode; 103 struct mount *mntp = pmp->pm_mountp; 104 struct direntry *direntptr; 105 struct denode *ldep; 106 struct vnode *nvp, *xvp; 107 struct buf *bp; 108 109 #ifdef MSDOSFS_DEBUG 110 printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n", 111 pmp, dirclust, diroffset, depp); 112 #endif 113 114 /* 115 * On FAT32 filesystems, root is a (more or less) normal 116 * directory 117 */ 118 if (FAT32(pmp) && dirclust == MSDOSFSROOT) 119 dirclust = pmp->pm_rootdirblk; 120 121 /* 122 * See if the denode is in the denode cache. Use the location of 123 * the directory entry to compute the hash value. For subdir use 124 * address of "." entry. For root dir (if not FAT32) use cluster 125 * MSDOSFSROOT, offset MSDOSFSROOT_OFS 126 * 127 * NOTE: The check for de_refcnt > 0 below insures the denode being 128 * examined does not represent an unlinked but still open file. 129 * These files are not to be accessible even when the directory 130 * entry that represented the file happens to be reused while the 131 * deleted file is still open. 132 */ 133 inode = (uint64_t)pmp->pm_bpcluster * dirclust + diroffset; 134 135 error = vfs_hash_get(mntp, inode, LK_EXCLUSIVE, curthread, &nvp, 136 de_vncmpf, &inode); 137 if (error) 138 return (error); 139 if (nvp != NULL) { 140 *depp = VTODE(nvp); 141 KASSERT((*depp)->de_dirclust == dirclust, ("wrong dirclust")); 142 KASSERT((*depp)->de_diroffset == diroffset, ("wrong diroffset")); 143 return (0); 144 } 145 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO); 146 147 /* 148 * Directory entry was not in cache, have to create a vnode and 149 * copy it from the passed disk buffer. 150 */ 151 /* getnewvnode() does a VREF() on the vnode */ 152 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp); 153 if (error) { 154 *depp = NULL; 155 free(ldep, M_MSDOSFSNODE); 156 return error; 157 } 158 nvp->v_data = ldep; 159 ldep->de_vnode = nvp; 160 ldep->de_flag = 0; 161 ldep->de_dirclust = dirclust; 162 ldep->de_diroffset = diroffset; 163 ldep->de_inode = inode; 164 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL); 165 fc_purge(ldep, 0); /* init the FAT cache for this denode */ 166 error = insmntque(nvp, mntp); 167 if (error != 0) { 168 free(ldep, M_MSDOSFSNODE); 169 *depp = NULL; 170 return (error); 171 } 172 error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp, 173 de_vncmpf, &inode); 174 if (error) { 175 *depp = NULL; 176 return (error); 177 } 178 if (xvp != NULL) { 179 *depp = xvp->v_data; 180 return (0); 181 } 182 183 ldep->de_pmp = pmp; 184 ldep->de_refcnt = 1; 185 /* 186 * Copy the directory entry into the denode area of the vnode. 187 */ 188 if ((dirclust == MSDOSFSROOT 189 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) 190 && diroffset == MSDOSFSROOT_OFS) { 191 /* 192 * Directory entry for the root directory. There isn't one, 193 * so we manufacture one. We should probably rummage 194 * through the root directory and find a label entry (if it 195 * exists), and then use the time and date from that entry 196 * as the time and date for the root denode. 197 */ 198 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */ 199 200 ldep->de_Attributes = ATTR_DIRECTORY; 201 ldep->de_LowerCase = 0; 202 if (FAT32(pmp)) 203 ldep->de_StartCluster = pmp->pm_rootdirblk; 204 /* de_FileSize will be filled in further down */ 205 else { 206 ldep->de_StartCluster = MSDOSFSROOT; 207 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE; 208 } 209 /* 210 * fill in time and date so that fattime2timespec() doesn't 211 * spit up when called from msdosfs_getattr() with root 212 * denode 213 */ 214 ldep->de_CHun = 0; 215 ldep->de_CTime = 0x0000; /* 00:00:00 */ 216 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 217 | (1 << DD_DAY_SHIFT); 218 /* Jan 1, 1980 */ 219 ldep->de_ADate = ldep->de_CDate; 220 ldep->de_MTime = ldep->de_CTime; 221 ldep->de_MDate = ldep->de_CDate; 222 /* leave the other fields as garbage */ 223 } else { 224 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 225 if (error) { 226 /* 227 * The denode does not contain anything useful, so 228 * it would be wrong to leave it on its hash chain. 229 * Arrange for vput() to just forget about it. 230 */ 231 ldep->de_Name[0] = SLOT_DELETED; 232 233 vput(nvp); 234 *depp = NULL; 235 return (error); 236 } 237 (void)DE_INTERNALIZE(ldep, direntptr); 238 brelse(bp); 239 } 240 241 /* 242 * Fill in a few fields of the vnode and finish filling in the 243 * denode. Then return the address of the found denode. 244 */ 245 if (ldep->de_Attributes & ATTR_DIRECTORY) { 246 /* 247 * Since DOS directory entries that describe directories 248 * have 0 in the filesize field, we take this opportunity 249 * to find out the length of the directory and plug it into 250 * the denode structure. 251 */ 252 u_long size; 253 254 /* 255 * XXX it sometimes happens that the "." entry has cluster 256 * number 0 when it shouldn't. Use the actual cluster number 257 * instead of what is written in directory entry. 258 */ 259 if (diroffset == 0 && ldep->de_StartCluster != dirclust) { 260 #ifdef MSDOSFS_DEBUG 261 printf("deget(): \".\" entry at clust %lu != %lu\n", 262 dirclust, ldep->de_StartCluster); 263 #endif 264 ldep->de_StartCluster = dirclust; 265 } 266 267 nvp->v_type = VDIR; 268 if (ldep->de_StartCluster != MSDOSFSROOT) { 269 error = pcbmap(ldep, 0xffff, 0, &size, 0); 270 if (error == E2BIG) { 271 ldep->de_FileSize = de_cn2off(pmp, size); 272 error = 0; 273 } else { 274 #ifdef MSDOSFS_DEBUG 275 printf("deget(): pcbmap returned %d\n", error); 276 #endif 277 } 278 } 279 } else 280 nvp->v_type = VREG; 281 ldep->de_modrev = init_va_filerev(); 282 *depp = ldep; 283 return (0); 284 } 285 286 int 287 deupdat(struct denode *dep, int waitfor) 288 { 289 struct direntry dir; 290 struct timespec ts; 291 struct buf *bp; 292 struct direntry *dirp; 293 int error; 294 295 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) { 296 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS | 297 DE_MODIFIED); 298 return (0); 299 } 300 vfs_timestamp(&ts); 301 DETIMES(dep, &ts, &ts, &ts); 302 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0) 303 return (0); 304 dep->de_flag &= ~DE_MODIFIED; 305 if (DETOV(dep)->v_vflag & VV_ROOT) 306 return (EINVAL); 307 if (dep->de_refcnt <= 0) 308 return (0); 309 error = readde(dep, &bp, &dirp); 310 if (error) 311 return (error); 312 DE_EXTERNALIZE(&dir, dep); 313 if (bcmp(dirp, &dir, sizeof(dir)) == 0) { 314 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) { 315 brelse(bp); 316 return (0); 317 } 318 } else 319 *dirp = dir; 320 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) 321 bp->b_flags |= B_CLUSTEROK; 322 if (waitfor) 323 error = bwrite(bp); 324 else if (vm_page_count_severe() || buf_dirty_count_severe()) 325 bawrite(bp); 326 else 327 bdwrite(bp); 328 return (error); 329 } 330 331 /* 332 * Truncate the file described by dep to the length specified by length. 333 */ 334 int 335 detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred) 336 { 337 int error; 338 int allerror; 339 u_long eofentry; 340 u_long chaintofree; 341 daddr_t bn; 342 int boff; 343 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 344 struct buf *bp; 345 struct msdosfsmount *pmp = dep->de_pmp; 346 347 #ifdef MSDOSFS_DEBUG 348 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags); 349 #endif 350 351 /* 352 * Disallow attempts to truncate the root directory since it is of 353 * fixed size. That's just the way dos filesystems are. We use 354 * the VROOT bit in the vnode because checking for the directory 355 * bit and a startcluster of 0 in the denode is not adequate to 356 * recognize the root directory at this point in a file or 357 * directory's life. 358 */ 359 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) { 360 #ifdef MSDOSFS_DEBUG 361 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 362 dep->de_dirclust, dep->de_diroffset); 363 #endif 364 return (EINVAL); 365 } 366 367 if (dep->de_FileSize < length) { 368 vnode_pager_setsize(DETOV(dep), length); 369 return deextend(dep, length, cred); 370 } 371 372 /* 373 * If the desired length is 0 then remember the starting cluster of 374 * the file and set the StartCluster field in the directory entry 375 * to 0. If the desired length is not zero, then get the number of 376 * the last cluster in the shortened file. Then get the number of 377 * the first cluster in the part of the file that is to be freed. 378 * Then set the next cluster pointer in the last cluster of the 379 * file to CLUST_EOFE. 380 */ 381 if (length == 0) { 382 chaintofree = dep->de_StartCluster; 383 dep->de_StartCluster = 0; 384 eofentry = ~0; 385 } else { 386 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 387 &eofentry, 0); 388 if (error) { 389 #ifdef MSDOSFS_DEBUG 390 printf("detrunc(): pcbmap fails %d\n", error); 391 #endif 392 return (error); 393 } 394 } 395 396 fc_purge(dep, de_clcount(pmp, length)); 397 398 /* 399 * If the new length is not a multiple of the cluster size then we 400 * must zero the tail end of the new last cluster in case it 401 * becomes part of the file again because of a seek. 402 */ 403 if ((boff = length & pmp->pm_crbomask) != 0) { 404 if (isadir) { 405 bn = cntobn(pmp, eofentry); 406 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 407 NOCRED, &bp); 408 } else { 409 error = bread(DETOV(dep), de_cluster(pmp, length), 410 pmp->pm_bpcluster, cred, &bp); 411 } 412 if (error) { 413 #ifdef MSDOSFS_DEBUG 414 printf("detrunc(): bread fails %d\n", error); 415 #endif 416 return (error); 417 } 418 memset(bp->b_data + boff, 0, pmp->pm_bpcluster - boff); 419 if ((flags & IO_SYNC) != 0) 420 bwrite(bp); 421 else 422 bdwrite(bp); 423 } 424 425 /* 426 * Write out the updated directory entry. Even if the update fails 427 * we free the trailing clusters. 428 */ 429 dep->de_FileSize = length; 430 if (!isadir) 431 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 432 allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster); 433 #ifdef MSDOSFS_DEBUG 434 if (allerror) 435 printf("detrunc(): vtruncbuf error %d\n", allerror); 436 #endif 437 error = deupdat(dep, !DOINGASYNC((DETOV(dep)))); 438 if (error != 0 && allerror == 0) 439 allerror = error; 440 #ifdef MSDOSFS_DEBUG 441 printf("detrunc(): allerror %d, eofentry %lu\n", 442 allerror, eofentry); 443 #endif 444 445 /* 446 * If we need to break the cluster chain for the file then do it 447 * now. 448 */ 449 if (eofentry != ~0) { 450 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 451 &chaintofree, CLUST_EOFE); 452 if (error) { 453 #ifdef MSDOSFS_DEBUG 454 printf("detrunc(): fatentry errors %d\n", error); 455 #endif 456 return (error); 457 } 458 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 459 eofentry); 460 } 461 462 /* 463 * Now free the clusters removed from the file because of the 464 * truncation. 465 */ 466 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 467 freeclusterchain(pmp, chaintofree); 468 469 return (allerror); 470 } 471 472 /* 473 * Extend the file described by dep to length specified by length. 474 */ 475 int 476 deextend(struct denode *dep, u_long length, struct ucred *cred) 477 { 478 struct msdosfsmount *pmp = dep->de_pmp; 479 u_long count; 480 int error; 481 482 /* 483 * The root of a DOS filesystem cannot be extended. 484 */ 485 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) 486 return (EINVAL); 487 488 /* 489 * Directories cannot be extended. 490 */ 491 if (dep->de_Attributes & ATTR_DIRECTORY) 492 return (EISDIR); 493 494 if (length <= dep->de_FileSize) 495 panic("deextend: file too large"); 496 497 /* 498 * Compute the number of clusters to allocate. 499 */ 500 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 501 if (count > 0) { 502 if (count > pmp->pm_freeclustercount) 503 return (ENOSPC); 504 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 505 if (error) { 506 /* truncate the added clusters away again */ 507 (void) detrunc(dep, dep->de_FileSize, 0, cred); 508 return (error); 509 } 510 } 511 dep->de_FileSize = length; 512 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 513 return (deupdat(dep, !DOINGASYNC(DETOV(dep)))); 514 } 515 516 /* 517 * Move a denode to its correct hash queue after the file it represents has 518 * been moved to a new directory. 519 */ 520 void 521 reinsert(struct denode *dep) 522 { 523 struct vnode *vp; 524 525 /* 526 * Fix up the denode cache. If the denode is for a directory, 527 * there is nothing to do since the hash is based on the starting 528 * cluster of the directory file and that hasn't changed. If for a 529 * file the hash is based on the location of the directory entry, 530 * so we must remove it from the cache and re-enter it with the 531 * hash based on the new location of the directory entry. 532 */ 533 #if 0 534 if (dep->de_Attributes & ATTR_DIRECTORY) 535 return; 536 #endif 537 vp = DETOV(dep); 538 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust + 539 dep->de_diroffset; 540 vfs_hash_rehash(vp, dep->de_inode); 541 } 542 543 int 544 msdosfs_reclaim(struct vop_reclaim_args *ap) 545 { 546 struct vnode *vp = ap->a_vp; 547 struct denode *dep = VTODE(vp); 548 549 #ifdef MSDOSFS_DEBUG 550 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n", 551 dep, dep->de_Name, dep->de_refcnt); 552 #endif 553 554 /* 555 * Remove the denode from its hash chain. 556 */ 557 vfs_hash_remove(vp); 558 /* 559 * Purge old data structures associated with the denode. 560 */ 561 #if 0 /* XXX */ 562 dep->de_flag = 0; 563 #endif 564 free(dep, M_MSDOSFSNODE); 565 vp->v_data = NULL; 566 567 return (0); 568 } 569 570 int 571 msdosfs_inactive(struct vop_inactive_args *ap) 572 { 573 struct vnode *vp = ap->a_vp; 574 struct denode *dep = VTODE(vp); 575 int error = 0; 576 577 #ifdef MSDOSFS_DEBUG 578 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]); 579 #endif 580 581 /* 582 * Ignore denodes related to stale file handles. 583 */ 584 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 585 goto out; 586 587 /* 588 * If the file has been deleted and it is on a read/write 589 * filesystem, then truncate the file, and mark the directory slot 590 * as empty. (This may not be necessary for the dos filesystem.) 591 */ 592 #ifdef MSDOSFS_DEBUG 593 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %llx, MNT_RDONLY %llx\n", 594 dep, dep->de_refcnt, (unsigned long long)vp->v_mount->mnt_flag, 595 (unsigned long long)MNT_RDONLY); 596 #endif 597 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 598 error = detrunc(dep, (u_long) 0, 0, NOCRED); 599 dep->de_flag |= DE_UPDATE; 600 dep->de_Name[0] = SLOT_DELETED; 601 } 602 deupdat(dep, 0); 603 604 out: 605 /* 606 * If we are done with the denode, reclaim it 607 * so that it can be reused immediately. 608 */ 609 #ifdef MSDOSFS_DEBUG 610 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 611 vrefcnt(vp), dep->de_Name[0]); 612 #endif 613 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 614 vrecycle(vp); 615 return (error); 616 } 617