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 } 145 146 /* 147 * Do the malloc before the getnewvnode since doing so afterward 148 * might cause a bogus v_data pointer to get dereferenced 149 * elsewhere if malloc should block. 150 */ 151 ldep = malloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO); 152 153 /* 154 * Directory entry was not in cache, have to create a vnode and 155 * copy it from the passed disk buffer. 156 */ 157 /* getnewvnode() does a VREF() on the vnode */ 158 error = getnewvnode("msdosfs", mntp, &msdosfs_vnodeops, &nvp); 159 if (error) { 160 *depp = NULL; 161 free(ldep, M_MSDOSFSNODE); 162 return error; 163 } 164 nvp->v_data = ldep; 165 ldep->de_vnode = nvp; 166 ldep->de_flag = 0; 167 ldep->de_dirclust = dirclust; 168 ldep->de_diroffset = diroffset; 169 ldep->de_inode = inode; 170 lockmgr(nvp->v_vnlock, LK_EXCLUSIVE, NULL); 171 fc_purge(ldep, 0); /* init the fat cache for this denode */ 172 error = insmntque(nvp, mntp); 173 if (error != 0) { 174 free(ldep, M_MSDOSFSNODE); 175 *depp = NULL; 176 return (error); 177 } 178 error = vfs_hash_insert(nvp, inode, LK_EXCLUSIVE, curthread, &xvp, 179 de_vncmpf, &inode); 180 if (error) { 181 *depp = NULL; 182 return (error); 183 } 184 if (xvp != NULL) { 185 *depp = xvp->v_data; 186 return (0); 187 } 188 189 ldep->de_pmp = pmp; 190 ldep->de_refcnt = 1; 191 /* 192 * Copy the directory entry into the denode area of the vnode. 193 */ 194 if ((dirclust == MSDOSFSROOT 195 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) 196 && diroffset == MSDOSFSROOT_OFS) { 197 /* 198 * Directory entry for the root directory. There isn't one, 199 * so we manufacture one. We should probably rummage 200 * through the root directory and find a label entry (if it 201 * exists), and then use the time and date from that entry 202 * as the time and date for the root denode. 203 */ 204 nvp->v_vflag |= VV_ROOT; /* should be further down XXX */ 205 206 ldep->de_Attributes = ATTR_DIRECTORY; 207 ldep->de_LowerCase = 0; 208 if (FAT32(pmp)) 209 ldep->de_StartCluster = pmp->pm_rootdirblk; 210 /* de_FileSize will be filled in further down */ 211 else { 212 ldep->de_StartCluster = MSDOSFSROOT; 213 ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE; 214 } 215 /* 216 * fill in time and date so that fattime2timespec() doesn't 217 * spit up when called from msdosfs_getattr() with root 218 * denode 219 */ 220 ldep->de_CHun = 0; 221 ldep->de_CTime = 0x0000; /* 00:00:00 */ 222 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 223 | (1 << DD_DAY_SHIFT); 224 /* Jan 1, 1980 */ 225 ldep->de_ADate = ldep->de_CDate; 226 ldep->de_MTime = ldep->de_CTime; 227 ldep->de_MDate = ldep->de_CDate; 228 /* leave the other fields as garbage */ 229 } else { 230 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 231 if (error) { 232 /* 233 * The denode does not contain anything useful, so 234 * it would be wrong to leave it on its hash chain. 235 * Arrange for vput() to just forget about it. 236 */ 237 ldep->de_Name[0] = SLOT_DELETED; 238 239 vput(nvp); 240 *depp = NULL; 241 return (error); 242 } 243 (void)DE_INTERNALIZE(ldep, direntptr); 244 brelse(bp); 245 } 246 247 /* 248 * Fill in a few fields of the vnode and finish filling in the 249 * denode. Then return the address of the found denode. 250 */ 251 if (ldep->de_Attributes & ATTR_DIRECTORY) { 252 /* 253 * Since DOS directory entries that describe directories 254 * have 0 in the filesize field, we take this opportunity 255 * to find out the length of the directory and plug it into 256 * the denode structure. 257 */ 258 u_long size; 259 260 /* 261 * XXX it sometimes happens that the "." entry has cluster 262 * number 0 when it shouldn't. Use the actual cluster number 263 * instead of what is written in directory entry. 264 */ 265 if (diroffset == 0 && ldep->de_StartCluster != dirclust) { 266 #ifdef MSDOSFS_DEBUG 267 printf("deget(): \".\" entry at clust %lu != %lu\n", 268 dirclust, ldep->de_StartCluster); 269 #endif 270 ldep->de_StartCluster = dirclust; 271 } 272 273 nvp->v_type = VDIR; 274 if (ldep->de_StartCluster != MSDOSFSROOT) { 275 error = pcbmap(ldep, 0xffff, 0, &size, 0); 276 if (error == E2BIG) { 277 ldep->de_FileSize = de_cn2off(pmp, size); 278 error = 0; 279 } else { 280 #ifdef MSDOSFS_DEBUG 281 printf("deget(): pcbmap returned %d\n", error); 282 #endif 283 } 284 } 285 } else 286 nvp->v_type = VREG; 287 ldep->de_modrev = init_va_filerev(); 288 *depp = ldep; 289 return (0); 290 } 291 292 int 293 deupdat(dep, waitfor) 294 struct denode *dep; 295 int waitfor; 296 { 297 int error; 298 struct buf *bp; 299 struct direntry *dirp; 300 struct timespec ts; 301 302 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) 303 return (0); 304 getnanotime(&ts); 305 DETIMES(dep, &ts, &ts, &ts); 306 if ((dep->de_flag & DE_MODIFIED) == 0) 307 return (0); 308 dep->de_flag &= ~DE_MODIFIED; 309 if (dep->de_Attributes & ATTR_DIRECTORY) 310 return (0); 311 if (dep->de_refcnt <= 0) 312 return (0); 313 error = readde(dep, &bp, &dirp); 314 if (error) 315 return (error); 316 DE_EXTERNALIZE(dirp, dep); 317 if (waitfor) 318 return (bwrite(bp)); 319 else { 320 bdwrite(bp); 321 return (0); 322 } 323 } 324 325 /* 326 * Truncate the file described by dep to the length specified by length. 327 */ 328 int 329 detrunc(dep, length, flags, cred, td) 330 struct denode *dep; 331 u_long length; 332 int flags; 333 struct ucred *cred; 334 struct thread *td; 335 { 336 int error; 337 int allerror; 338 u_long eofentry; 339 u_long chaintofree; 340 daddr_t bn; 341 int boff; 342 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 343 struct buf *bp; 344 struct msdosfsmount *pmp = dep->de_pmp; 345 346 #ifdef MSDOSFS_DEBUG 347 printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags); 348 #endif 349 350 /* 351 * Disallow attempts to truncate the root directory since it is of 352 * fixed size. That's just the way dos filesystems are. We use 353 * the VROOT bit in the vnode because checking for the directory 354 * bit and a startcluster of 0 in the denode is not adequate to 355 * recognize the root directory at this point in a file or 356 * directory's life. 357 */ 358 if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) { 359 #ifdef MSDOSFS_DEBUG 360 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 361 dep->de_dirclust, dep->de_diroffset); 362 #endif 363 return (EINVAL); 364 } 365 366 if (dep->de_FileSize < length) { 367 vnode_pager_setsize(DETOV(dep), length); 368 return deextend(dep, length, cred); 369 } 370 371 /* 372 * If the desired length is 0 then remember the starting cluster of 373 * the file and set the StartCluster field in the directory entry 374 * to 0. If the desired length is not zero, then get the number of 375 * the last cluster in the shortened file. Then get the number of 376 * the first cluster in the part of the file that is to be freed. 377 * Then set the next cluster pointer in the last cluster of the 378 * file to CLUST_EOFE. 379 */ 380 if (length == 0) { 381 chaintofree = dep->de_StartCluster; 382 dep->de_StartCluster = 0; 383 eofentry = ~0; 384 } else { 385 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 386 &eofentry, 0); 387 if (error) { 388 #ifdef MSDOSFS_DEBUG 389 printf("detrunc(): pcbmap fails %d\n", error); 390 #endif 391 return (error); 392 } 393 } 394 395 fc_purge(dep, de_clcount(pmp, length)); 396 397 /* 398 * If the new length is not a multiple of the cluster size then we 399 * must zero the tail end of the new last cluster in case it 400 * becomes part of the file again because of a seek. 401 */ 402 if ((boff = length & pmp->pm_crbomask) != 0) { 403 if (isadir) { 404 bn = cntobn(pmp, eofentry); 405 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 406 NOCRED, &bp); 407 if (error) { 408 brelse(bp); 409 #ifdef MSDOSFS_DEBUG 410 printf("detrunc(): bread fails %d\n", error); 411 #endif 412 return (error); 413 } 414 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff); 415 if (flags & IO_SYNC) 416 bwrite(bp); 417 else 418 bdwrite(bp); 419 } 420 } 421 422 /* 423 * Write out the updated directory entry. Even if the update fails 424 * we free the trailing clusters. 425 */ 426 dep->de_FileSize = length; 427 if (!isadir) 428 dep->de_flag |= DE_UPDATE | DE_MODIFIED; 429 allerror = vtruncbuf(DETOV(dep), cred, td, length, pmp->pm_bpcluster); 430 #ifdef MSDOSFS_DEBUG 431 if (allerror) 432 printf("detrunc(): vtruncbuf error %d\n", allerror); 433 #endif 434 error = deupdat(dep, !DOINGASYNC((DETOV(dep)))); 435 if (error != 0 && allerror == 0) 436 allerror = error; 437 #ifdef MSDOSFS_DEBUG 438 printf("detrunc(): allerror %d, eofentry %lu\n", 439 allerror, eofentry); 440 #endif 441 442 /* 443 * If we need to break the cluster chain for the file then do it 444 * now. 445 */ 446 if (eofentry != ~0) { 447 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 448 &chaintofree, CLUST_EOFE); 449 if (error) { 450 #ifdef MSDOSFS_DEBUG 451 printf("detrunc(): fatentry errors %d\n", error); 452 #endif 453 return (error); 454 } 455 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 456 eofentry); 457 } 458 459 /* 460 * Now free the clusters removed from the file because of the 461 * truncation. 462 */ 463 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 464 freeclusterchain(pmp, chaintofree); 465 466 return (allerror); 467 } 468 469 /* 470 * Extend the file described by dep to length specified by length. 471 */ 472 int 473 deextend(dep, length, cred) 474 struct denode *dep; 475 u_long length; 476 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, NULL); 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(dep) 522 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(ap) 546 struct vop_reclaim_args /* { 547 struct vnode *a_vp; 548 } */ *ap; 549 { 550 struct vnode *vp = ap->a_vp; 551 struct denode *dep = VTODE(vp); 552 553 #ifdef MSDOSFS_DEBUG 554 printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n", 555 dep, dep->de_Name, dep->de_refcnt); 556 #endif 557 558 /* 559 * Destroy the vm object and flush associated pages. 560 */ 561 vnode_destroy_vobject(vp); 562 /* 563 * Remove the denode from its hash chain. 564 */ 565 vfs_hash_remove(vp); 566 /* 567 * Purge old data structures associated with the denode. 568 */ 569 #if 0 /* XXX */ 570 dep->de_flag = 0; 571 #endif 572 free(dep, M_MSDOSFSNODE); 573 vp->v_data = NULL; 574 575 return (0); 576 } 577 578 int 579 msdosfs_inactive(ap) 580 struct vop_inactive_args /* { 581 struct vnode *a_vp; 582 struct thread *a_td; 583 } */ *ap; 584 { 585 struct vnode *vp = ap->a_vp; 586 struct denode *dep = VTODE(vp); 587 struct thread *td = ap->a_td; 588 int error = 0; 589 590 #ifdef MSDOSFS_DEBUG 591 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]); 592 #endif 593 594 /* 595 * Ignore denodes related to stale file handles. 596 */ 597 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 598 goto out; 599 600 /* 601 * If the file has been deleted and it is on a read/write 602 * filesystem, then truncate the file, and mark the directory slot 603 * as empty. (This may not be necessary for the dos filesystem.) 604 */ 605 #ifdef MSDOSFS_DEBUG 606 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n", 607 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY); 608 #endif 609 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 610 error = detrunc(dep, (u_long) 0, 0, NOCRED, td); 611 dep->de_flag |= DE_UPDATE; 612 dep->de_Name[0] = SLOT_DELETED; 613 } 614 deupdat(dep, 0); 615 616 out: 617 /* 618 * If we are done with the denode, reclaim it 619 * so that it can be reused immediately. 620 */ 621 #ifdef MSDOSFS_DEBUG 622 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 623 vrefcnt(vp), dep->de_Name[0]); 624 #endif 625 if (dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY) 626 vrecycle(vp, td); 627 return (error); 628 } 629