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