1/* $OpenBSD: msdosfs_denode.c,v 1.68 2023/03/08 04:43:08 guenther 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/buf.h> 56#include <sys/vnode.h> 57#include <sys/lock.h> 58#include <sys/kernel.h> /* defines "time" */ 59#include <sys/dirent.h> 60#include <sys/namei.h> 61 62#include <crypto/siphash.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 70u_int msdosfs_dehash(dev_t, uint32_t, uint32_t); 71 72struct denode **dehashtbl; 73SIPHASH_KEY dehashkey; 74u_long dehash; /* size of hash table - 1 */ 75#define DEHASH(dev, dcl, doff) msdosfs_dehash((dev), (dcl), (doff)) 76 77static struct denode *msdosfs_hashget(dev_t, uint32_t, uint32_t); 78static int msdosfs_hashins(struct denode *); 79static void msdosfs_hashrem(struct denode *); 80 81int 82msdosfs_init(struct vfsconf *vfsp) 83{ 84 dehashtbl = hashinit(initialvnodes / 2, M_MSDOSFSMNT, M_WAITOK, &dehash); 85 arc4random_buf(&dehashkey, sizeof(dehashkey)); 86 return (0); 87} 88 89u_int 90msdosfs_dehash(dev_t dev, uint32_t dirclust, uint32_t diroff) 91{ 92 SIPHASH_CTX ctx; 93 94 SipHash24_Init(&ctx, &dehashkey); 95 SipHash24_Update(&ctx, &dev, sizeof(dev)); 96 SipHash24_Update(&ctx, &dirclust, sizeof(dirclust)); 97 SipHash24_Update(&ctx, &diroff, sizeof(diroff)); 98 99 return (SipHash24_End(&ctx) & dehash); 100} 101 102static struct denode * 103msdosfs_hashget(dev_t dev, uint32_t dirclust, uint32_t diroff) 104{ 105 struct denode *dep; 106 107 for (;;) 108 for (dep = dehashtbl[DEHASH(dev, dirclust, diroff)]; ; 109 dep = dep->de_next) { 110 if (dep == NULL) 111 return (NULL); 112 if (dirclust == dep->de_dirclust && 113 diroff == dep->de_diroffset && 114 dev == dep->de_dev && 115 dep->de_refcnt != 0) { 116 struct vnode *vp = DETOV(dep); 117 118 if (!vget(vp, LK_EXCLUSIVE)) 119 return (dep); 120 break; 121 } 122 } 123 /* NOTREACHED */ 124} 125 126static int 127msdosfs_hashins(struct denode *dep) 128{ 129 struct denode **depp, *deq; 130 131 depp = &dehashtbl[DEHASH(dep->de_dev, dep->de_dirclust, 132 dep->de_diroffset)]; 133 134 for (deq = *depp; deq; deq = deq->de_next) { 135 if (dep->de_dirclust == deq->de_dirclust && 136 dep->de_diroffset == deq->de_diroffset && 137 dep->de_dev == deq->de_dev && 138 deq->de_refcnt != 0) { 139 return (EEXIST); 140 } 141 } 142 143 if ((deq = *depp) != NULL) 144 deq->de_prev = &dep->de_next; 145 dep->de_next = deq; 146 dep->de_prev = depp; 147 *depp = dep; 148 return (0); 149} 150 151static void 152msdosfs_hashrem(struct denode *dep) 153{ 154 struct denode *deq; 155 156 if (dep->de_prev == NULL) 157 return; 158 159 if ((deq = dep->de_next) != NULL) 160 deq->de_prev = dep->de_prev; 161 *dep->de_prev = deq; 162#ifdef DIAGNOSTIC 163 dep->de_next = NULL; 164 dep->de_prev = NULL; 165#endif 166} 167 168/* 169 * If deget() succeeds it returns with the gotten denode locked(). 170 * 171 * pmp - address of msdosfsmount structure of the filesystem containing 172 * the denode of interest. The pm_dev field and the address of 173 * the msdosfsmount structure are used. 174 * dirclust - which cluster bp contains, if dirclust is 0 (root directory) 175 * diroffset is relative to the beginning of the root directory, 176 * otherwise it is cluster relative. 177 * diroffset - offset past begin of cluster of denode we want 178 * depp - returns the address of the gotten denode. 179 */ 180int 181deget(struct msdosfsmount *pmp, uint32_t dirclust, uint32_t diroffset, 182 struct denode **depp) 183{ 184 int error; 185 extern const struct vops msdosfs_vops; 186 struct direntry *direntptr; 187 struct denode *ldep; 188 struct vnode *nvp; 189 struct buf *bp; 190 191#ifdef MSDOSFS_DEBUG 192 printf("deget(pmp %p, dirclust %d, diroffset %x, depp %p)\n", 193 pmp, dirclust, diroffset, depp); 194#endif 195 196 /* 197 * On FAT32 filesystems, root is a (more or less) normal 198 * directory 199 */ 200 if (FAT32(pmp) && dirclust == MSDOSFSROOT) 201 dirclust = pmp->pm_rootdirblk; 202 203 /* 204 * See if the denode is in the denode cache. Use the location of 205 * the directory entry to compute the hash value. For subdir use 206 * address of "." entry. For root dir (if not FAT32) use cluster 207 * MSDOSFSROOT, offset MSDOSFSROOT_OFS 208 * 209 * NOTE: The check for de_refcnt > 0 below insures the denode being 210 * examined does not represent an unlinked but still open file. 211 * These files are not to be accessible even when the directory 212 * entry that represented the file happens to be reused while the 213 * deleted file is still open. 214 */ 215retry: 216 ldep = msdosfs_hashget(pmp->pm_dev, dirclust, diroffset); 217 if (ldep) { 218 *depp = ldep; 219 return (0); 220 } 221 222 /* 223 * Directory entry was not in cache, have to create a vnode and 224 * copy it from the passed disk buffer. 225 */ 226 /* getnewvnode() does a vref() on the vnode */ 227 error = getnewvnode(VT_MSDOSFS, pmp->pm_mountp, &msdosfs_vops, &nvp); 228 if (error) { 229 *depp = 0; 230 return (error); 231 } 232 ldep = malloc(sizeof(*ldep), M_MSDOSFSNODE, M_WAITOK | M_ZERO); 233 rrw_init_flags(&ldep->de_lock, "denode", RWL_DUPOK | RWL_IS_VNODE); 234 nvp->v_data = ldep; 235 ldep->de_vnode = nvp; 236 ldep->de_flag = 0; 237 ldep->de_devvp = 0; 238 ldep->de_lockf = 0; 239 ldep->de_dev = pmp->pm_dev; 240 ldep->de_dirclust = dirclust; 241 ldep->de_diroffset = diroffset; 242 fc_purge(ldep, 0); /* init the fat cache for this denode */ 243 244 /* 245 * Insert the denode into the hash queue and lock the denode so it 246 * can't be accessed until we've read it in and have done what we 247 * need to it. 248 */ 249 vn_lock(nvp, LK_EXCLUSIVE | LK_RETRY); 250 error = msdosfs_hashins(ldep); 251 252 if (error) { 253 vput (nvp); 254 255 if (error == EEXIST) 256 goto retry; 257 258 return (error); 259 } 260 261 ldep->de_pmp = pmp; 262 ldep->de_devvp = pmp->pm_devvp; 263 ldep->de_refcnt = 1; 264 /* 265 * Copy the directory entry into the denode area of the vnode. 266 */ 267 if ((dirclust == MSDOSFSROOT 268 || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk)) 269 && diroffset == MSDOSFSROOT_OFS) { 270 /* 271 * Directory entry for the root directory. There isn't one, 272 * so we manufacture one. We should probably rummage 273 * through the root directory and find a label entry (if it 274 * exists), and then use the time and date from that entry 275 * as the time and date for the root denode. 276 */ 277 nvp->v_flag |= VROOT; /* should be further down XXX */ 278 279 ldep->de_Attributes = ATTR_DIRECTORY; 280 if (FAT32(pmp)) 281 ldep->de_StartCluster = pmp->pm_rootdirblk; 282 /* de_FileSize will be filled in further down */ 283 else { 284 ldep->de_StartCluster = MSDOSFSROOT; 285 ldep->de_FileSize = pmp->pm_rootdirsize * pmp->pm_BytesPerSec; 286 } 287 /* 288 * fill in time and date so that dos2unixtime() doesn't 289 * spit up when called from msdosfs_getattr() with root 290 * denode 291 */ 292 ldep->de_CTime = 0x0000; /* 00:00:00 */ 293 ldep->de_CTimeHundredth = 0; 294 ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT) 295 | (1 << DD_DAY_SHIFT); 296 /* Jan 1, 1980 */ 297 ldep->de_ADate = ldep->de_CDate; 298 ldep->de_MTime = ldep->de_CTime; 299 ldep->de_MDate = ldep->de_CDate; 300 /* leave the other fields as garbage */ 301 } else { 302 error = readep(pmp, dirclust, diroffset, &bp, &direntptr); 303 if (error) 304 return (error); 305 DE_INTERNALIZE(ldep, direntptr); 306 brelse(bp); 307 } 308 309 /* 310 * Fill in a few fields of the vnode and finish filling in the 311 * denode. Then return the address of the found denode. 312 */ 313 if (ldep->de_Attributes & ATTR_DIRECTORY) { 314 /* 315 * Since DOS directory entries that describe directories 316 * have 0 in the filesize field, we take this opportunity 317 * to find out the length of the directory and plug it into 318 * the denode structure. 319 */ 320 uint32_t size; 321 322 nvp->v_type = VDIR; 323 if (ldep->de_StartCluster != MSDOSFSROOT) { 324 error = pcbmap(ldep, CLUST_END, 0, &size, 0); 325 if (error == E2BIG) { 326 ldep->de_FileSize = de_cn2off(pmp, size); 327 error = 0; 328 } else if (error) { 329 printf("deget(): pcbmap returned %d\n", error); 330 return (error); 331 } 332 } 333 } else 334 nvp->v_type = VREG; 335 vref(ldep->de_devvp); 336 *depp = ldep; 337 return (0); 338} 339 340int 341deupdat(struct denode *dep, int waitfor) 342{ 343 struct buf *bp; 344 struct direntry *dirp; 345 int error; 346 struct timespec ts; 347 348 if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY) 349 return (0); 350 getnanotime(&ts); 351 DETIMES(dep, &ts, &ts, &ts); 352 if ((dep->de_flag & DE_MODIFIED) == 0) 353 return (0); 354 dep->de_flag &= ~DE_MODIFIED; 355 if (dep->de_Attributes & ATTR_DIRECTORY) 356 return (0); 357 if (dep->de_refcnt <= 0) 358 return (0); 359 error = readde(dep, &bp, &dirp); 360 if (error) 361 return (error); 362 DE_EXTERNALIZE(dirp, dep); 363 if (waitfor) 364 return (bwrite(bp)); 365 else { 366 bdwrite(bp); 367 return (0); 368 } 369} 370 371/* 372 * Truncate the file described by dep to the length specified by length. 373 */ 374int 375detrunc(struct denode *dep, uint32_t length, int flags, struct ucred *cred, 376 struct proc *p) 377{ 378 int error; 379 int allerror; 380 int vflags; 381 uint32_t eofentry; 382 uint32_t chaintofree = 0; 383 daddr_t bn; 384 int boff; 385 int isadir = dep->de_Attributes & ATTR_DIRECTORY; 386 struct buf *bp; 387 struct msdosfsmount *pmp = dep->de_pmp; 388 389#ifdef MSDOSFS_DEBUG 390 printf("detrunc(): file %.11s, length %u, flags %d\n", 391 dep->de_Name, length, flags); 392#endif 393 394 /* 395 * Disallow attempts to truncate the root directory since it is of 396 * fixed size. That's just the way dos filesystems are. We use 397 * the VROOT bit in the vnode because checking for the directory 398 * bit and a startcluster of 0 in the denode is not adequate to 399 * recognize the root directory at this point in a file or 400 * directory's life. 401 */ 402 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) { 403 printf("detrunc(): can't truncate root directory, clust %u, offset %u\n", 404 dep->de_dirclust, dep->de_diroffset); 405 return (EINVAL); 406 } 407 408 uvm_vnp_setsize(DETOV(dep), length); 409 410 if (dep->de_FileSize < length) 411 return (deextend(dep, length, cred)); 412 413 /* 414 * If the desired length is 0 then remember the starting cluster of 415 * the file and set the StartCluster field in the directory entry 416 * to 0. If the desired length is not zero, then get the number of 417 * the last cluster in the shortened file. Then get the number of 418 * the first cluster in the part of the file that is to be freed. 419 * Then set the next cluster pointer in the last cluster of the 420 * file to CLUST_EOFE. 421 */ 422 if (length == 0) { 423 chaintofree = dep->de_StartCluster; 424 dep->de_StartCluster = 0; 425 eofentry = ~0; 426 } else { 427 error = pcbmap(dep, de_clcount(pmp, length) - 1, 0, 428 &eofentry, 0); 429 if (error) { 430#ifdef MSDOSFS_DEBUG 431 printf("detrunc(): pcbmap fails %d\n", error); 432#endif 433 return (error); 434 } 435 } 436 437 fc_purge(dep, de_clcount(pmp, length)); 438 439 /* 440 * If the new length is not a multiple of the cluster size then we 441 * must zero the tail end of the new last cluster in case it 442 * becomes part of the file again because of a seek. 443 */ 444 if ((boff = length & pmp->pm_crbomask) != 0) { 445 if (isadir) { 446 bn = cntobn(pmp, eofentry); 447 error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster, &bp); 448 } else { 449 bn = de_blk(pmp, length); 450 error = bread(DETOV(dep), bn, pmp->pm_bpcluster, &bp); 451 } 452 if (error) { 453 brelse(bp); 454#ifdef MSDOSFS_DEBUG 455 printf("detrunc(): bread fails %d\n", error); 456#endif 457 return (error); 458 } 459 uvm_vnp_uncache(DETOV(dep)); 460 /* 461 * is this the right place for it? 462 */ 463 bzero(bp->b_data + boff, pmp->pm_bpcluster - boff); 464 if (flags & IO_SYNC) 465 bwrite(bp); 466 else 467 bdwrite(bp); 468 } 469 470 /* 471 * Write out the updated directory entry. Even if the update fails 472 * we free the trailing clusters. 473 */ 474 dep->de_FileSize = length; 475 if (!isadir) 476 dep->de_flag |= DE_UPDATE|DE_MODIFIED; 477 vflags = (length > 0 ? V_SAVE : 0) | V_SAVEMETA; 478 vinvalbuf(DETOV(dep), vflags, cred, p, 0, INFSLP); 479 allerror = deupdat(dep, 1); 480#ifdef MSDOSFS_DEBUG 481 printf("detrunc(): allerror %d, eofentry %d\n", 482 allerror, eofentry); 483#endif 484 485 /* 486 * If we need to break the cluster chain for the file then do it 487 * now. 488 */ 489 if (eofentry != ~0) { 490 error = fatentry(FAT_GET_AND_SET, pmp, eofentry, 491 &chaintofree, CLUST_EOFE); 492 if (error) { 493#ifdef MSDOSFS_DEBUG 494 printf("detrunc(): fatentry errors %d\n", error); 495#endif 496 return (error); 497 } 498 fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1), 499 eofentry); 500 } 501 502 /* 503 * Now free the clusters removed from the file because of the 504 * truncation. 505 */ 506 if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree)) 507 freeclusterchain(pmp, chaintofree); 508 509 return (allerror); 510} 511 512/* 513 * Extend the file described by dep to length specified by length. 514 */ 515int 516deextend(struct denode *dep, uint32_t length, struct ucred *cred) 517{ 518 struct msdosfsmount *pmp = dep->de_pmp; 519 uint32_t count; 520 int error; 521 522 /* 523 * The root of a DOS filesystem cannot be extended. 524 */ 525 if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) 526 return (EINVAL); 527 528 /* 529 * Directories cannot be extended. 530 */ 531 if (dep->de_Attributes & ATTR_DIRECTORY) 532 return (EISDIR); 533 534 if (length <= dep->de_FileSize) 535 panic("deextend: file too large"); 536 537 /* 538 * Compute the number of clusters to allocate. 539 */ 540 count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize); 541 if (count > 0) { 542 if (count > pmp->pm_freeclustercount) 543 return (ENOSPC); 544 error = extendfile(dep, count, NULL, NULL, DE_CLEAR); 545 if (error) { 546 /* truncate the added clusters away again */ 547 (void) detrunc(dep, dep->de_FileSize, 0, cred, curproc); 548 return (error); 549 } 550 } 551 552 dep->de_FileSize = length; 553 dep->de_flag |= DE_UPDATE|DE_MODIFIED; 554 return (deupdat(dep, 1)); 555} 556 557/* 558 * Move a denode to its correct hash queue after the file it represents has 559 * been moved to a new directory. 560 */ 561void 562reinsert(struct denode *dep) 563{ 564 /* 565 * Fix up the denode cache. If the denode is for a directory, 566 * there is nothing to do since the hash is based on the starting 567 * cluster of the directory file and that hasn't changed. If for a 568 * file the hash is based on the location of the directory entry, 569 * so we must remove it from the cache and re-enter it with the 570 * hash based on the new location of the directory entry. 571 */ 572 if (dep->de_Attributes & ATTR_DIRECTORY) 573 return; 574 msdosfs_hashrem(dep); 575 msdosfs_hashins(dep); 576} 577 578int 579msdosfs_reclaim(void *v) 580{ 581 struct vop_reclaim_args *ap = v; 582 struct vnode *vp = ap->a_vp; 583 struct denode *dep = VTODE(vp); 584#ifdef DIAGNOSTIC 585 extern int prtactive; 586 587 if (prtactive && vp->v_usecount != 0) 588 vprint("msdosfs_reclaim(): pushing active", vp); 589#endif 590 591#ifdef MSDOSFS_DEBUG 592 printf("msdosfs_reclaim(): dep %p, file %.11s, refcnt %ld\n", 593 dep, dep->de_Name, dep->de_refcnt); 594#endif 595 596 /* 597 * Remove the denode from its hash chain. 598 */ 599 msdosfs_hashrem(dep); 600 /* 601 * Purge old data structures associated with the denode. 602 */ 603 cache_purge(vp); 604 if (dep->de_devvp) { 605 vrele(dep->de_devvp); 606 dep->de_devvp = 0; 607 } 608#if 0 /* XXX */ 609 dep->de_flag = 0; 610#endif 611 free(dep, M_MSDOSFSNODE, 0); 612 vp->v_data = NULL; 613 return (0); 614} 615 616int 617msdosfs_inactive(void *v) 618{ 619 struct vop_inactive_args *ap = v; 620 struct vnode *vp = ap->a_vp; 621 struct denode *dep = VTODE(vp); 622 int error; 623#ifdef DIAGNOSTIC 624 extern int prtactive; 625 626 if (prtactive && vp->v_usecount != 0) 627 vprint("msdosfs_inactive(): pushing active", vp); 628#endif 629 630#ifdef MSDOSFS_DEBUG 631 printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, 632 dep->de_Name[0]); 633#endif 634 635 error = 0; 636 637 /* 638 * Get rid of denodes related to stale file handles. 639 */ 640 if (dep->de_Name[0] == SLOT_DELETED) 641 goto out; 642 643 /* 644 * If the file has been deleted and it is on a read/write 645 * filesystem, then truncate the file, and mark the directory slot 646 * as empty. (This may not be necessary for the dos filesystem.) 647 */ 648#ifdef MSDOSFS_DEBUG 649 printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, " 650 "MNT_RDONLY %x\n", dep, dep->de_refcnt, vp->v_mount->mnt_flag, 651 MNT_RDONLY); 652#endif 653 if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) { 654 error = detrunc(dep, (uint32_t)0, 0, NOCRED, ap->a_p); 655 dep->de_Name[0] = SLOT_DELETED; 656 } 657 deupdat(dep, 0); 658 659out: 660 VOP_UNLOCK(vp); 661 /* 662 * If we are done with the denode, reclaim it 663 * so that it can be reused immediately. 664 */ 665#ifdef MSDOSFS_DEBUG 666 printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n", 667 vp->v_usecount, dep->de_Name[0]); 668#endif 669 if (dep->de_Name[0] == SLOT_DELETED) 670 vrecycle(vp, ap->a_p); 671 return (error); 672} 673