1 /* $OpenBSD: msdosfs_denode.c,v 1.35 2008/01/13 21:27:09 krw Exp $ */ 2 /* $NetBSD: msdosfs_denode.c,v 1.23 1997/10/17 11:23:58 ws 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/mount.h> 54 #include <sys/malloc.h> 55 #include <sys/proc.h> 56 #include <sys/buf.h> 57 #include <sys/vnode.h> 58 #include <sys/kernel.h> /* defines "time" */ 59 #include <sys/dirent.h> 60 #include <sys/namei.h> 61 62 #include <uvm/uvm_extern.h> 63 64 #include <msdosfs/bpb.h> 65 #include <msdosfs/msdosfsmount.h> 66 #include <msdosfs/direntry.h> 67 #include <msdosfs/denode.h> 68 #include <msdosfs/fat.h> 69 70 struct denode **dehashtbl; 71 u_long dehash; /* size of hash table - 1 */ 72 #define DEHASH(dev, dcl, doff) (((dev) + (dcl) + (doff) / sizeof(struct direntry)) \ 73 & dehash) 74 75 static struct denode *msdosfs_hashget(dev_t, uint32_t, uint32_t); 76 static int msdosfs_hashins(struct denode *); 77 static void msdosfs_hashrem(struct denode *); 78 79 /*ARGSUSED*/ 80 int 81 msdosfs_init(vfsp) 82 struct vfsconf *vfsp; 83 { 84 dehashtbl = hashinit(desiredvnodes/2, M_MSDOSFSMNT, M_WAITOK, &dehash); 85 return (0); 86 } 87 88 static struct denode * 89 msdosfs_hashget(dev, dirclust, diroff) 90 dev_t dev; 91 uint32_t dirclust; 92 uint32_t diroff; 93 { 94 struct denode *dep; 95 struct proc *p = curproc; /* XXX */ 96 97 for (;;) 98 for (dep = dehashtbl[DEHASH(dev, dirclust, diroff)];; 99 dep = dep->de_next) { 100 if (dep == NULL) 101 return (NULL); 102 if (dirclust == dep->de_dirclust && 103 diroff == dep->de_diroffset && 104 dev == dep->de_dev && 105 dep->de_refcnt != 0) { 106 struct vnode *vp = DETOV(dep); 107 108 if (!vget(vp, LK_EXCLUSIVE, p)) 109 return (dep); 110 break; 111 } 112 } 113 /* NOTREACHED */ 114 } 115 116 static int 117 msdosfs_hashins(dep) 118 struct denode *dep; 119 { 120 struct denode **depp, *deq; 121 122 depp = &dehashtbl[DEHASH(dep->de_dev, dep->de_dirclust, 123 dep->de_diroffset)]; 124 125 for (deq = *depp; deq; deq = deq->de_next) { 126 if (dep->de_dirclust == deq->de_dirclust && 127 dep->de_diroffset == deq->de_diroffset && 128 dep->de_dev == deq->de_dev && 129 deq->de_refcnt != 0) { 130 return (EEXIST); 131 } 132 } 133 134 if ((deq = *depp) != NULL) 135 deq->de_prev = &dep->de_next; 136 dep->de_next = deq; 137 dep->de_prev = depp; 138 *depp = dep; 139 return (0); 140 } 141 142 static void 143 msdosfs_hashrem(dep) 144 struct denode *dep; 145 { 146 struct denode *deq; 147 148 if (dep->de_prev == NULL) 149 return; 150 151 if ((deq = dep->de_next) != NULL) 152 deq->de_prev = dep->de_prev; 153 *dep->de_prev = deq; 154 #ifdef DIAGNOSTIC 155 dep->de_next = NULL; 156 dep->de_prev = NULL; 157 #endif 158 } 159 160 /* 161 * If deget() succeeds it returns with the gotten denode locked(). 162 * 163 * pmp - address of msdosfsmount structure of the filesystem containing 164 * the denode of interest. The pm_dev field and the address of 165 * the msdosfsmount structure are used. 166 * dirclust - which cluster bp contains, if dirclust is 0 (root directory) 167 * diroffset is relative to the beginning of the root directory, 168 * otherwise it is cluster relative. 169 * diroffset - offset past begin of cluster of denode we want 170 * depp - returns the address of the gotten denode. 171 */ 172 int 173 deget(pmp, dirclust, diroffset, depp) 174 struct msdosfsmount *pmp; /* so we know the maj/min number */ 175 uint32_t dirclust; /* cluster this dir entry came from */ 176 uint32_t diroffset; /* index of entry within the cluster */ 177 struct denode **depp; /* returns the addr of the gotten denode */ 178 { 179 int error; 180 extern int (**msdosfs_vnodeop_p)(void *); 181 struct direntry *direntptr; 182 struct denode *ldep; 183 struct vnode *nvp; 184 struct buf *bp; 185 struct proc *p = curproc; /* XXX */ 186 187 #ifdef MSDOSFS_DEBUG 188 printf("deget(pmp %08x, dirclust %d, diroffset %x, depp %08x)\n", 189 pmp, dirclust, diroffset, depp); 190 #endif 191 192 /* 193 * On FAT32 filesystems, root is a (more or less) normal 194 * directory 195 */ 196 if (FAT32(pmp) && dirclust == MSDOSFSROOT) 197 dirclust = pmp->pm_rootdirblk; 198 199 /* 200 * See if the denode is in the denode cache. Use the location of 201 * the directory entry to compute the hash value. For subdir use 202 * address of "." entry. For root dir (if not FAT32) use cluster 203 * MSDOSFSROOT, offset MSDOSFSROOT_OFS 204 * 205 * NOTE: The check for de_refcnt > 0 below insures the denode being 206 * examined does not represent an unlinked but still open file. 207 * These files are not to be accessible even when the directory 208 * entry that represented the file happens to be reused while the 209 * deleted file is still open. 210 */ 211 retry: 212 ldep = msdosfs_hashget(pmp->pm_dev, dirclust, diroffset); 213 if (ldep) { 214 *depp = ldep; 215 return (0); 216 } 217 218 /* 219 * Directory entry was not in cache, have to create a vnode and 220 * copy it from the passed disk buffer. 221 */ 222 /* getnewvnode() does a VREF() on the vnode */ 223 error = getnewvnode(VT_MSDOSFS, pmp->pm_mountp, 224 msdosfs_vnodeop_p, &nvp); 225 if (error) { 226 *depp = 0; 227 return (error); 228 } 229 ldep = malloc(sizeof(*ldep), M_MSDOSFSNODE, M_WAITOK | M_ZERO); 230 lockinit(&ldep->de_lock, PINOD, "denode", 0, 0); 231 nvp->v_data = ldep; 232 ldep->de_vnode = nvp; 233 ldep->de_flag = 0; 234 ldep->de_devvp = 0; 235 ldep->de_lockf = 0; 236 ldep->de_dev = pmp->pm_dev; 237 ldep->de_dirclust = dirclust; 238 ldep->de_diroffset = diroffset; 239 fc_purge(ldep, 0); /* init the fat cache for this denode */ 240 241 /* 242 * Insert the denode into the hash queue and lock the denode so it 243 * can't be accessed until we've read it in and have done what we 244 * need to it. 245 */ 246 vn_lock(nvp, LK_EXCLUSIVE | LK_RETRY, p); 247 error = msdosfs_hashins(ldep); 248 249 if (error) { 250 vput (nvp); 251 252 if (error == EEXIST) 253 goto retry; 254 255 return (error); 256 } 257 258 ldep->de_pmp = pmp; 259 ldep->de_devvp = pmp->pm_devvp; 260 ldep->de_refcnt = 1; 261 /* 262 * Copy the directory entry into the denode area of the vnode. 263 */ 264 if ((dirclust == MSDOSFSROOT 265 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) 266 && diroffset == MSDOSFSROOT_OFS) { 267 /* 268 * Directory entry for the root directory. There isn't one, 269 * so we manufacture one. We should probably rummage 270 * through the root directory and find a label entry (if it 271 * exists), and then use the time and date from that entry 272 * as the time and date for the root denode. 273 */ 274 nvp->v_flag |= VROOT; /* should be further down XXX */ 275 276 ldep->de_Attributes = ATTR_DIRECTORY; 277 if (FAT32(pmp)) 278 ldep->de_StartCluster = pmp->pm_rootdirblk; 279 /* de_FileSize will be filled in further down */ 280 else { 281 ldep->de_StartCluster = MSDOSFSROOT; 282 ldep->de_FileSize = pmp->pm_rootdirsize * pmp->pm_BytesPerSec; 283 } 284 /* 285 * fill in time and date so that dos2unixtime() doesn't 286 * spit up when called from msdosfs_getattr() with root 287 * denode 288 */ 289 ldep->de_CTime = 0x0000; /* 00:00:00 */ 290 ldep->de_CTimeHundredth = 0; 291 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 292 | (1 << DD_DAY_SHIFT); 293 /* Jan 1, 1980 */ 294 ldep->de_ADate = ldep->de_CDate; 295 ldep->de_MTime = ldep->de_CTime; 296 ldep->de_MDate = ldep->de_CDate; 297 /* leave the other fields as garbage */ 298 } else { 299 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 300 if (error) 301 return (error); 302 DE_INTERNALIZE(ldep, direntptr); 303 brelse(bp); 304 } 305 306 /* 307 * Fill in a few fields of the vnode and finish filling in the 308 * denode. Then return the address of the found denode. 309 */ 310 if (ldep->de_Attributes & ATTR_DIRECTORY) { 311 /* 312 * Since DOS directory entries that describe directories 313 * have 0 in the filesize field, we take this opportunity 314 * to find out the length of the directory and plug it into 315 * the denode structure. 316 */ 317 uint32_t size; 318 319 nvp->v_type = VDIR; 320 if (ldep->de_StartCluster != MSDOSFSROOT) { 321 error = pcbmap(ldep, 0xffff, 0, &size, 0); 322 if (error == E2BIG) { 323 ldep->de_FileSize = de_cn2off(pmp, size); 324 error = 0; 325 } else { 326 printf("deget(): pcbmap returned %d\n", error); 327 return (error); 328 } 329 } 330 } else 331 nvp->v_type = VREG; 332 VREF(ldep->de_devvp); 333 *depp = ldep; 334 return (0); 335 } 336 337 int 338 deupdat(dep, waitfor) 339 struct denode *dep; 340 int waitfor; 341 { 342 struct buf *bp; 343 struct direntry *dirp; 344 int error; 345 struct timespec ts; 346 347 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) 348 return (0); 349 getnanotime(&ts); 350 DETIMES(dep, &ts, &ts, &ts); 351 if ((dep->de_flag & DE_MODIFIED) == 0) 352 return (0); 353 dep->de_flag &= ~DE_MODIFIED; 354 if (dep->de_Attributes & ATTR_DIRECTORY) 355 return (0); 356 if (dep->de_refcnt <= 0) 357 return (0); 358 error = readde(dep, &bp, &dirp); 359 if (error) 360 return (error); 361 DE_EXTERNALIZE(dirp, dep); 362 if (waitfor) 363 return (bwrite(bp)); 364 else { 365 bdwrite(bp); 366 return (0); 367 } 368 } 369 370 /* 371 * Truncate the file described by dep to the length specified by length. 372 */ 373 int 374 detrunc(dep, length, flags, cred, p) 375 struct denode *dep; 376 uint32_t length; 377 int flags; 378 struct ucred *cred; 379 struct proc *p; 380 { 381 int error; 382 int allerror; 383 int vflags; 384 uint32_t eofentry; 385 uint32_t chaintofree; 386 daddr64_t bn; 387 int boff; 388 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 389 struct buf *bp; 390 struct msdosfsmount *pmp = dep->de_pmp; 391 392 #ifdef MSDOSFS_DEBUG 393 printf("detrunc(): file %s, length %ld, flags %d\n", dep->de_Name, length, flags); 394 #endif 395 396 /* 397 * Disallow attempts to truncate the root directory since it is of 398 * fixed size. That's just the way dos filesystems are. We use 399 * the VROOT bit in the vnode because checking for the directory 400 * bit and a startcluster of 0 in the denode is not adequate to 401 * recognize the root directory at this point in a file or 402 * directory's life. 403 */ 404 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) { 405 printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n", 406 dep->de_dirclust, dep->de_diroffset); 407 return (EINVAL); 408 } 409 410 uvm_vnp_setsize(DETOV(dep), length); 411 412 if (dep->de_FileSize < length) 413 return (deextend(dep, length, cred)); 414 415 /* 416 * If the desired length is 0 then remember the starting cluster of 417 * the file and set the StartCluster field in the directory entry 418 * to 0. If the desired length is not zero, then get the number of 419 * the last cluster in the shortened file. Then get the number of 420 * the first cluster in the part of the file that is to be freed. 421 * Then set the next cluster pointer in the last cluster of the 422 * file to CLUST_EOFE. 423 */ 424 if (length == 0) { 425 chaintofree = dep->de_StartCluster; 426 dep->de_StartCluster = 0; 427 eofentry = ~0; 428 } else { 429 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 430 &eofentry, 0); 431 if (error) { 432 #ifdef MSDOSFS_DEBUG 433 printf("detrunc(): pcbmap fails %d\n", error); 434 #endif 435 return (error); 436 } 437 } 438 439 fc_purge(dep, de_clcount(pmp, length)); 440 441 /* 442 * If the new length is not a multiple of the cluster size then we 443 * must zero the tail end of the new last cluster in case it 444 * becomes part of the file again because of a seek. 445 */ 446 if ((boff = length & pmp->pm_crbomask) != 0) { 447 if (isadir) { 448 bn = cntobn(pmp, eofentry); 449 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, 450 NOCRED, &bp); 451 } else { 452 bn = de_blk(pmp, length); 453 error = bread(DETOV(dep), bn, pmp->pm_bpcluster, 454 NOCRED, &bp); 455 } 456 if (error) { 457 brelse(bp); 458 #ifdef MSDOSFS_DEBUG 459 printf("detrunc(): bread fails %d\n", error); 460 #endif 461 return (error); 462 } 463 uvm_vnp_uncache(DETOV(dep)); 464 /* 465 * is this the right place for it? 466 */ 467 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff); 468 if (flags & IO_SYNC) 469 bwrite(bp); 470 else 471 bdwrite(bp); 472 } 473 474 /* 475 * Write out the updated directory entry. Even if the update fails 476 * we free the trailing clusters. 477 */ 478 dep->de_FileSize = length; 479 if (!isadir) 480 dep->de_flag |= DE_UPDATE|DE_MODIFIED; 481 vflags = (length > 0 ? V_SAVE : 0) | V_SAVEMETA; 482 vinvalbuf(DETOV(dep), vflags, cred, p, 0, 0); 483 allerror = deupdat(dep, 1); 484 #ifdef MSDOSFS_DEBUG 485 printf("detrunc(): allerror %d, eofentry %d\n", 486 allerror, eofentry); 487 #endif 488 489 /* 490 * If we need to break the cluster chain for the file then do it 491 * now. 492 */ 493 if (eofentry != ~0) { 494 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 495 &chaintofree, CLUST_EOFE); 496 if (error) { 497 #ifdef MSDOSFS_DEBUG 498 printf("detrunc(): fatentry errors %d\n", error); 499 #endif 500 return (error); 501 } 502 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 503 eofentry); 504 } 505 506 /* 507 * Now free the clusters removed from the file because of the 508 * truncation. 509 */ 510 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 511 freeclusterchain(pmp, chaintofree); 512 513 return (allerror); 514 } 515 516 /* 517 * Extend the file described by dep to length specified by length. 518 */ 519 int 520 deextend(dep, length, cred) 521 struct denode *dep; 522 uint32_t length; 523 struct ucred *cred; 524 { 525 struct msdosfsmount *pmp = dep->de_pmp; 526 uint32_t count; 527 int error; 528 529 /* 530 * The root of a DOS filesystem cannot be extended. 531 */ 532 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) 533 return (EINVAL); 534 535 /* 536 * Directories cannot be extended. 537 */ 538 if (dep->de_Attributes & ATTR_DIRECTORY) 539 return (EISDIR); 540 541 if (length <= dep->de_FileSize) 542 panic("deextend: file too large"); 543 544 /* 545 * Compute the number of clusters to allocate. 546 */ 547 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 548 if (count > 0) { 549 if (count > pmp->pm_freeclustercount) 550 return (ENOSPC); 551 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 552 if (error) { 553 /* truncate the added clusters away again */ 554 (void) detrunc(dep, dep->de_FileSize, 0, cred, NULL); 555 return (error); 556 } 557 } 558 559 dep->de_FileSize = length; 560 dep->de_flag |= DE_UPDATE|DE_MODIFIED; 561 return (deupdat(dep, 1)); 562 } 563 564 /* 565 * Move a denode to its correct hash queue after the file it represents has 566 * been moved to a new directory. 567 */ 568 void 569 reinsert(dep) 570 struct denode *dep; 571 { 572 /* 573 * Fix up the denode cache. If the denode is for a directory, 574 * there is nothing to do since the hash is based on the starting 575 * cluster of the directory file and that hasn't changed. If for a 576 * file the hash is based on the location of the directory entry, 577 * so we must remove it from the cache and re-enter it with the 578 * hash based on the new location of the directory entry. 579 */ 580 if (dep->de_Attributes & ATTR_DIRECTORY) 581 return; 582 msdosfs_hashrem(dep); 583 msdosfs_hashins(dep); 584 } 585 586 int 587 msdosfs_reclaim(v) 588 void *v; 589 { 590 struct vop_reclaim_args *ap = v; 591 struct vnode *vp = ap->a_vp; 592 struct denode *dep = VTODE(vp); 593 #ifdef DIAGNOSTIC 594 extern int prtactive; 595 596 if (prtactive && vp->v_usecount != 0) 597 vprint("msdosfs_reclaim(): pushing active", vp); 598 #endif 599 600 #ifdef MSDOSFS_DEBUG 601 printf("msdosfs_reclaim(): dep %08x, file %s, refcnt %d\n", 602 dep, dep->de_Name, dep->de_refcnt); 603 #endif 604 605 /* 606 * Remove the denode from its hash chain. 607 */ 608 msdosfs_hashrem(dep); 609 /* 610 * Purge old data structures associated with the denode. 611 */ 612 cache_purge(vp); 613 if (dep->de_devvp) { 614 vrele(dep->de_devvp); 615 dep->de_devvp = 0; 616 } 617 #if 0 /* XXX */ 618 dep->de_flag = 0; 619 #endif 620 free(dep, M_MSDOSFSNODE); 621 vp->v_data = NULL; 622 return (0); 623 } 624 625 int 626 msdosfs_inactive(v) 627 void *v; 628 { 629 struct vop_inactive_args *ap = v; 630 struct vnode *vp = ap->a_vp; 631 struct denode *dep = VTODE(vp); 632 struct proc *p = ap->a_p; 633 int error; 634 #ifdef DIAGNOSTIC 635 extern int prtactive; 636 637 if (prtactive && vp->v_usecount != 0) 638 vprint("msdosfs_inactive(): pushing active", vp); 639 #endif 640 641 #ifdef MSDOSFS_DEBUG 642 printf("msdosfs_inactive(): dep %08x, de_Name[0] %x\n", dep, dep->de_Name[0]); 643 #endif 644 645 error = 0; 646 647 /* 648 * Get rid of denodes related to stale file handles. 649 */ 650 if (dep->de_Name[0] == SLOT_DELETED) 651 goto out; 652 653 /* 654 * If the file has been deleted and it is on a read/write 655 * filesystem, then truncate the file, and mark the directory slot 656 * as empty. (This may not be necessary for the dos filesystem.) 657 */ 658 #ifdef MSDOSFS_DEBUG 659 printf("msdosfs_inactive(): dep %08x, refcnt %d, mntflag %x, MNT_RDONLY %x\n", 660 dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY); 661 #endif 662 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 663 error = detrunc(dep, (uint32_t)0, 0, NOCRED, NULL); 664 dep->de_Name[0] = SLOT_DELETED; 665 } 666 deupdat(dep, 0); 667 668 out: 669 VOP_UNLOCK(vp, 0, p); 670 /* 671 * If we are done with the denode, reclaim it 672 * so that it can be reused immediately. 673 */ 674 #ifdef MSDOSFS_DEBUG 675 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", vp->v_usecount, 676 dep->de_Name[0]); 677 #endif 678 if (dep->de_Name[0] == SLOT_DELETED) 679 vrecycle(vp, p); 680 return (error); 681 } 682