1 /* $FreeBSD$ */ 2 /* $NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $ */ 3 4 /*- 5 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 6 * Copyright (C) 1994, 1995, 1997 TooLs GmbH. 7 * All rights reserved. 8 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below). 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by TooLs GmbH. 21 * 4. The name of TooLs GmbH may not be used to endorse or promote products 22 * derived from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 29 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 30 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 32 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 33 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 /*- 36 * Written by Paul Popelka (paulp@uts.amdahl.com) 37 * 38 * You can do anything you want with this software, just don't say you wrote 39 * it, and don't remove this notice. 40 * 41 * This software is provided "as is". 42 * 43 * The author supplies this software to be publicly redistributed on the 44 * understanding that the author is not responsible for the correct 45 * functioning of this software in any circumstances and is not liable for 46 * any damages caused by this software. 47 * 48 * October 1992 49 */ 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/buf.h> 54 #include <sys/clock.h> 55 #include <sys/kernel.h> 56 #include <sys/malloc.h> 57 #include <sys/mount.h> 58 #include <sys/vnode.h> 59 60 #include <vm/vm.h> 61 #include <vm/vm_extern.h> 62 63 #include <fs/msdosfs/bpb.h> 64 #include <fs/msdosfs/direntry.h> 65 #include <fs/msdosfs/denode.h> 66 #include <fs/msdosfs/fat.h> 67 #include <fs/msdosfs/msdosfsmount.h> 68 69 static MALLOC_DEFINE(M_MSDOSFSNODE, "msdosfs_node", "MSDOSFS vnode private part"); 70 71 static int 72 de_vncmpf(struct vnode *vp, void *arg) 73 { 74 struct denode *de; 75 uint64_t *a; 76 77 a = arg; 78 de = VTODE(vp); 79 return (de->de_inode != *a); 80 } 81 82 /* 83 * If deget() succeeds it returns with the gotten denode locked(). 84 * 85 * pmp - address of msdosfsmount structure of the filesystem containing 86 * the denode of interest. The address of 87 * the msdosfsmount structure are used. 88 * dirclust - which cluster bp contains, if dirclust is 0 (root directory) 89 * diroffset is relative to the beginning of the root directory, 90 * otherwise it is cluster relative. 91 * diroffset - offset past begin of cluster of denode we want 92 * depp - returns the address of the gotten denode. 93 */ 94 int 95 deget(pmp, dirclust, diroffset, depp) 96 struct msdosfsmount *pmp; /* so we know the maj/min number */ 97 u_long dirclust; /* cluster this dir entry came from */ 98 u_long diroffset; /* index of entry within the cluster */ 99 struct denode **depp; /* returns the addr of the gotten denode */ 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(dep, waitfor) 288 struct denode *dep; 289 int waitfor; 290 { 291 struct direntry dir; 292 struct timespec ts; 293 struct buf *bp; 294 struct direntry *dirp; 295 int error; 296 297 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) { 298 dep->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS | 299 DE_MODIFIED); 300 return (0); 301 } 302 getnanotime(&ts); 303 DETIMES(dep, &ts, &ts, &ts); 304 if ((dep->de_flag & DE_MODIFIED) == 0 && waitfor == 0) 305 return (0); 306 dep->de_flag &= ~DE_MODIFIED; 307 if (dep->de_Attributes & ATTR_DIRECTORY) 308 return (0); 309 if (dep->de_refcnt <= 0) 310 return (0); 311 error = readde(dep, &bp, &dirp); 312 if (error) 313 return (error); 314 DE_EXTERNALIZE(&dir, dep); 315 if (bcmp(dirp, &dir, sizeof(dir)) == 0) { 316 if (waitfor == 0 || (bp->b_flags & B_DELWRI) == 0) { 317 brelse(bp); 318 return (0); 319 } 320 } else 321 *dirp = dir; 322 if ((DETOV(dep)->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) 323 bp->b_flags |= B_CLUSTEROK; 324 if (waitfor) 325 error = bwrite(bp); 326 else if (vm_page_count_severe() || buf_dirty_count_severe()) 327 bawrite(bp); 328 else 329 bdwrite(bp); 330 return (error); 331 } 332 333 /* 334 * Truncate the file described by dep to the length specified by length. 335 */ 336 int 337 detrunc(dep, length, flags, cred) 338 struct denode *dep; 339 u_long length; 340 int flags; 341 struct ucred *cred; 342 { 343 int error; 344 int allerror; 345 u_long eofentry; 346 u_long chaintofree; 347 daddr_t bn; 348 int boff; 349 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 350 struct buf *bp; 351 struct msdosfsmount *pmp = dep->de_pmp; 352 353 #ifdef MSDOSFS_DEBUG 354 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags); 355 #endif 356 357 /* 358 * Disallow attempts to truncate the root directory since it is of 359 * fixed size. That's just the way dos filesystems are. We use 360 * the VROOT bit in the vnode because checking for the directory 361 * bit and a startcluster of 0 in the denode is not adequate to 362 * recognize the root directory at this point in a file or 363 * directory's life. 364 */ 365 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) { 366 #ifdef MSDOSFS_DEBUG 367 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 368 dep->de_dirclust, dep->de_diroffset); 369 #endif 370 return (EINVAL); 371 } 372 373 if (dep->de_FileSize < length) { 374 vnode_pager_setsize(DETOV(dep), length); 375 return deextend(dep, length, cred); 376 } 377 378 /* 379 * If the desired length is 0 then remember the starting cluster of 380 * the file and set the StartCluster field in the directory entry 381 * to 0. If the desired length is not zero, then get the number of 382 * the last cluster in the shortened file. Then get the number of 383 * the first cluster in the part of the file that is to be freed. 384 * Then set the next cluster pointer in the last cluster of the 385 * file to CLUST_EOFE. 386 */ 387 if (length == 0) { 388 chaintofree = dep->de_StartCluster; 389 dep->de_StartCluster = 0; 390 eofentry = ~0; 391 } else { 392 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 393 &eofentry, 0); 394 if (error) { 395 #ifdef MSDOSFS_DEBUG 396 printf("detrunc(): pcbmap fails %d\n", error); 397 #endif 398 return (error); 399 } 400 } 401 402 fc_purge(dep, de_clcount(pmp, length)); 403 404 /* 405 * If the new length is not a multiple of the cluster size then we 406 * must zero the tail end of the new last cluster in case it 407 * becomes part of the file again because of a seek. 408 */ 409 if ((boff = length & pmp->pm_crbomask) != 0) { 410 if (isadir) { 411 bn = cntobn(pmp, eofentry); 412 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 413 NOCRED, &bp); 414 if (error) { 415 brelse(bp); 416 #ifdef MSDOSFS_DEBUG 417 printf("detrunc(): bread fails %d\n", error); 418 #endif 419 return (error); 420 } 421 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff); 422 if (flags & IO_SYNC) 423 bwrite(bp); 424 else 425 bdwrite(bp); 426 } 427 } 428 429 /* 430 * Write out the updated directory entry. Even if the update fails 431 * we free the trailing clusters. 432 */ 433 dep->de_FileSize = length; 434 if (!isadir) 435 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 436 allerror = vtruncbuf(DETOV(dep), cred, length, pmp->pm_bpcluster); 437 #ifdef MSDOSFS_DEBUG 438 if (allerror) 439 printf("detrunc(): vtruncbuf error %d\n", allerror); 440 #endif 441 error = deupdat(dep, !DOINGASYNC((DETOV(dep)))); 442 if (error != 0 && allerror == 0) 443 allerror = error; 444 #ifdef MSDOSFS_DEBUG 445 printf("detrunc(): allerror %d, eofentry %lu\n", 446 allerror, eofentry); 447 #endif 448 449 /* 450 * If we need to break the cluster chain for the file then do it 451 * now. 452 */ 453 if (eofentry != ~0) { 454 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 455 &chaintofree, CLUST_EOFE); 456 if (error) { 457 #ifdef MSDOSFS_DEBUG 458 printf("detrunc(): fatentry errors %d\n", error); 459 #endif 460 return (error); 461 } 462 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 463 eofentry); 464 } 465 466 /* 467 * Now free the clusters removed from the file because of the 468 * truncation. 469 */ 470 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 471 freeclusterchain(pmp, chaintofree); 472 473 return (allerror); 474 } 475 476 /* 477 * Extend the file described by dep to length specified by length. 478 */ 479 int 480 deextend(dep, length, cred) 481 struct denode *dep; 482 u_long length; 483 struct ucred *cred; 484 { 485 struct msdosfsmount *pmp = dep->de_pmp; 486 u_long count; 487 int error; 488 489 /* 490 * The root of a DOS filesystem cannot be extended. 491 */ 492 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) 493 return (EINVAL); 494 495 /* 496 * Directories cannot be extended. 497 */ 498 if (dep->de_Attributes & ATTR_DIRECTORY) 499 return (EISDIR); 500 501 if (length <= dep->de_FileSize) 502 panic("deextend: file too large"); 503 504 /* 505 * Compute the number of clusters to allocate. 506 */ 507 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 508 if (count > 0) { 509 if (count > pmp->pm_freeclustercount) 510 return (ENOSPC); 511 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 512 if (error) { 513 /* truncate the added clusters away again */ 514 (void) detrunc(dep, dep->de_FileSize, 0, cred); 515 return (error); 516 } 517 } 518 dep->de_FileSize = length; 519 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 520 return (deupdat(dep, !DOINGASYNC(DETOV(dep)))); 521 } 522 523 /* 524 * Move a denode to its correct hash queue after the file it represents has 525 * been moved to a new directory. 526 */ 527 void 528 reinsert(dep) 529 struct denode *dep; 530 { 531 struct vnode *vp; 532 533 /* 534 * Fix up the denode cache. If the denode is for a directory, 535 * there is nothing to do since the hash is based on the starting 536 * cluster of the directory file and that hasn't changed. If for a 537 * file the hash is based on the location of the directory entry, 538 * so we must remove it from the cache and re-enter it with the 539 * hash based on the new location of the directory entry. 540 */ 541 #if 0 542 if (dep->de_Attributes & ATTR_DIRECTORY) 543 return; 544 #endif 545 vp = DETOV(dep); 546 dep->de_inode = (uint64_t)dep->de_pmp->pm_bpcluster * dep->de_dirclust + 547 dep->de_diroffset; 548 vfs_hash_rehash(vp, dep->de_inode); 549 } 550 551 int 552 msdosfs_reclaim(ap) 553 struct vop_reclaim_args /* { 554 struct vnode *a_vp; 555 } */ *ap; 556 { 557 struct vnode *vp = ap->a_vp; 558 struct denode *dep = VTODE(vp); 559 560 #ifdef MSDOSFS_DEBUG 561 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n", 562 dep, dep->de_Name, dep->de_refcnt); 563 #endif 564 565 /* 566 * Destroy the vm object and flush associated pages. 567 */ 568 vnode_destroy_vobject(vp); 569 /* 570 * Remove the denode from its hash chain. 571 */ 572 vfs_hash_remove(vp); 573 /* 574 * Purge old data structures associated with the denode. 575 */ 576 #if 0 /* XXX */ 577 dep->de_flag = 0; 578 #endif 579 free(dep, M_MSDOSFSNODE); 580 vp->v_data = NULL; 581 582 return (0); 583 } 584 585 int 586 msdosfs_inactive(ap) 587 struct vop_inactive_args /* { 588 struct vnode *a_vp; 589 struct thread *a_td; 590 } */ *ap; 591 { 592 struct vnode *vp = ap->a_vp; 593 struct denode *dep = VTODE(vp); 594 int error = 0; 595 596 #ifdef MSDOSFS_DEBUG 597 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]); 598 #endif 599 600 /* 601 * Ignore denodes related to stale file handles. 602 */ 603 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 604 goto out; 605 606 /* 607 * If the file has been deleted and it is on a read/write 608 * filesystem, then truncate the file, and mark the directory slot 609 * as empty. (This may not be necessary for the dos filesystem.) 610 */ 611 #ifdef MSDOSFS_DEBUG 612 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n", 613 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY); 614 #endif 615 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 616 error = detrunc(dep, (u_long) 0, 0, NOCRED); 617 dep->de_flag |= DE_UPDATE; 618 dep->de_Name[0] = SLOT_DELETED; 619 } 620 deupdat(dep, 0); 621 622 out: 623 /* 624 * If we are done with the denode, reclaim it 625 * so that it can be reused immediately. 626 */ 627 #ifdef MSDOSFS_DEBUG 628 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 629 vrefcnt(vp), dep->de_Name[0]); 630 #endif 631 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 632 vrecycle(vp); 633 return (error); 634 } 635