msdosfs_lookup.c revision 204474
1/* $FreeBSD: head/sys/fs/msdosfs/msdosfs_lookup.c 204474 2010-02-28 17:17:29Z kib $ */ 2/* $NetBSD: msdosfs_lookup.c,v 1.37 1997/11/17 15:36:54 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/buf.h> 54#include <sys/mount.h> 55#include <sys/namei.h> 56#include <sys/vnode.h> 57 58#include <fs/msdosfs/bpb.h> 59#include <fs/msdosfs/direntry.h> 60#include <fs/msdosfs/denode.h> 61#include <fs/msdosfs/fat.h> 62#include <fs/msdosfs/msdosfsmount.h> 63 64static int msdosfs_lookup_(struct vnode *vdp, struct vnode **vpp, 65 struct componentname *cnp, u_int64_t *inum); 66static int msdosfs_deget_dotdot(struct vnode *vp, u_long cluster, int blkoff, 67 struct vnode **rvp); 68 69int 70msdosfs_lookup(struct vop_cachedlookup_args *ap) 71{ 72 73 return (msdosfs_lookup_(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL)); 74} 75 76/* 77 * When we search a directory the blocks containing directory entries are 78 * read and examined. The directory entries contain information that would 79 * normally be in the inode of a unix filesystem. This means that some of 80 * a directory's contents may also be in memory resident denodes (sort of 81 * an inode). This can cause problems if we are searching while some other 82 * process is modifying a directory. To prevent one process from accessing 83 * incompletely modified directory information we depend upon being the 84 * sole owner of a directory block. bread/brelse provide this service. 85 * This being the case, when a process modifies a directory it must first 86 * acquire the disk block that contains the directory entry to be modified. 87 * Then update the disk block and the denode, and then write the disk block 88 * out to disk. This way disk blocks containing directory entries and in 89 * memory denode's will be in synch. 90 */ 91static int 92msdosfs_lookup_(struct vnode *vdp, struct vnode **vpp, 93 struct componentname *cnp, u_int64_t *dd_inum) 94{ 95 struct mbnambuf nb; 96 daddr_t bn; 97 int error; 98 int slotcount; 99 int slotoffset = 0; 100 int frcn; 101 u_long cluster; 102 int blkoff; 103 int diroff; 104 int blsize; 105 int isadir; /* ~0 if found direntry is a directory */ 106 u_long scn; /* starting cluster number */ 107 struct vnode *pdp; 108 struct denode *dp; 109 struct denode *tdp; 110 struct msdosfsmount *pmp; 111 struct buf *bp = 0; 112 struct direntry *dep = NULL; 113 u_char dosfilename[12]; 114 int flags = cnp->cn_flags; 115 int nameiop = cnp->cn_nameiop; 116 int unlen; 117 u_int64_t inode1; 118 119 int wincnt = 1; 120 int chksum = -1, chksum_ok; 121 int olddos = 1; 122 123#ifdef MSDOSFS_DEBUG 124 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr); 125#endif 126 dp = VTODE(vdp); 127 pmp = dp->de_pmp; 128 if (vpp != NULL) 129 *vpp = NULL; 130#ifdef MSDOSFS_DEBUG 131 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n", 132 vdp, dp, dp->de_Attributes); 133#endif 134 135 restart: 136 /* 137 * If they are going after the . or .. entry in the root directory, 138 * they won't find it. DOS filesystems don't have them in the root 139 * directory. So, we fake it. deget() is in on this scam too. 140 */ 141 if ((vdp->v_vflag & VV_ROOT) && cnp->cn_nameptr[0] == '.' && 142 (cnp->cn_namelen == 1 || 143 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) { 144 isadir = ATTR_DIRECTORY; 145 scn = MSDOSFSROOT; 146#ifdef MSDOSFS_DEBUG 147 printf("msdosfs_lookup(): looking for . or .. in root directory\n"); 148#endif 149 cluster = MSDOSFSROOT; 150 blkoff = MSDOSFSROOT_OFS; 151 goto foundroot; 152 } 153 154 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename, 155 cnp->cn_namelen, 0, pmp)) { 156 case 0: 157 return (EINVAL); 158 case 1: 159 break; 160 case 2: 161 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr, 162 cnp->cn_namelen, pmp) + 1; 163 break; 164 case 3: 165 olddos = 0; 166 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr, 167 cnp->cn_namelen, pmp) + 1; 168 break; 169 } 170 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) { 171 wincnt = 1; 172 olddos = 1; 173 } 174 unlen = winLenFixup(cnp->cn_nameptr, cnp->cn_namelen); 175 176 /* 177 * Suppress search for slots unless creating 178 * file and at end of pathname, in which case 179 * we watch for a place to put the new file in 180 * case it doesn't already exist. 181 */ 182 slotcount = wincnt; 183 if ((nameiop == CREATE || nameiop == RENAME) && 184 (flags & ISLASTCN)) 185 slotcount = 0; 186 187#ifdef MSDOSFS_DEBUG 188 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n", 189 dosfilename, cnp->cn_namelen); 190#endif 191 /* 192 * Search the directory pointed at by vdp for the name pointed at 193 * by cnp->cn_nameptr. 194 */ 195 tdp = NULL; 196 mbnambuf_init(&nb); 197 /* 198 * The outer loop ranges over the clusters that make up the 199 * directory. Note that the root directory is different from all 200 * other directories. It has a fixed number of blocks that are not 201 * part of the pool of allocatable clusters. So, we treat it a 202 * little differently. The root directory starts at "cluster" 0. 203 */ 204 diroff = 0; 205 for (frcn = 0;; frcn++) { 206 error = pcbmap(dp, frcn, &bn, &cluster, &blsize); 207 if (error) { 208 if (error == E2BIG) 209 break; 210 return (error); 211 } 212 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 213 if (error) { 214 brelse(bp); 215 return (error); 216 } 217 for (blkoff = 0; blkoff < blsize; 218 blkoff += sizeof(struct direntry), 219 diroff += sizeof(struct direntry)) { 220 dep = (struct direntry *)(bp->b_data + blkoff); 221 /* 222 * If the slot is empty and we are still looking 223 * for an empty then remember this one. If the 224 * slot is not empty then check to see if it 225 * matches what we are looking for. If the slot 226 * has never been filled with anything, then the 227 * remainder of the directory has never been used, 228 * so there is no point in searching it. 229 */ 230 if (dep->deName[0] == SLOT_EMPTY || 231 dep->deName[0] == SLOT_DELETED) { 232 /* 233 * Drop memory of previous long matches 234 */ 235 chksum = -1; 236 mbnambuf_init(&nb); 237 238 if (slotcount < wincnt) { 239 slotcount++; 240 slotoffset = diroff; 241 } 242 if (dep->deName[0] == SLOT_EMPTY) { 243 brelse(bp); 244 goto notfound; 245 } 246 } else { 247 /* 248 * If there wasn't enough space for our winentries, 249 * forget about the empty space 250 */ 251 if (slotcount < wincnt) 252 slotcount = 0; 253 254 /* 255 * Check for Win95 long filename entry 256 */ 257 if (dep->deAttributes == ATTR_WIN95) { 258 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) 259 continue; 260 261 chksum = win2unixfn(&nb, 262 (struct winentry *)dep, chksum, 263 pmp); 264 continue; 265 } 266 267 chksum = winChkName(&nb, 268 (const u_char *)cnp->cn_nameptr, unlen, 269 chksum, pmp); 270 if (chksum == -2) { 271 chksum = -1; 272 continue; 273 } 274 275 /* 276 * Ignore volume labels (anywhere, not just 277 * the root directory). 278 */ 279 if (dep->deAttributes & ATTR_VOLUME) { 280 chksum = -1; 281 continue; 282 } 283 284 /* 285 * Check for a checksum or name match 286 */ 287 chksum_ok = (chksum == winChksum(dep->deName)); 288 if (!chksum_ok 289 && (!olddos || bcmp(dosfilename, dep->deName, 11))) { 290 chksum = -1; 291 continue; 292 } 293#ifdef MSDOSFS_DEBUG 294 printf("msdosfs_lookup(): match blkoff %d, diroff %d\n", 295 blkoff, diroff); 296#endif 297 /* 298 * Remember where this directory 299 * entry came from for whoever did 300 * this lookup. 301 */ 302 dp->de_fndoffset = diroff; 303 if (chksum_ok && nameiop == RENAME) { 304 /* 305 * Target had correct long name 306 * directory entries, reuse them 307 * as needed. 308 */ 309 dp->de_fndcnt = wincnt - 1; 310 } else { 311 /* 312 * Long name directory entries 313 * not present or corrupt, can only 314 * reuse dos directory entry. 315 */ 316 dp->de_fndcnt = 0; 317 } 318 319 goto found; 320 } 321 } /* for (blkoff = 0; .... */ 322 /* 323 * Release the buffer holding the directory cluster just 324 * searched. 325 */ 326 brelse(bp); 327 } /* for (frcn = 0; ; frcn++) */ 328 329notfound: 330 /* 331 * We hold no disk buffers at this point. 332 */ 333 334 /* 335 * Fixup the slot description to point to the place where 336 * we might put the new DOS direntry (putting the Win95 337 * long name entries before that) 338 */ 339 if (!slotcount) { 340 slotcount = 1; 341 slotoffset = diroff; 342 } 343 if (wincnt > slotcount) 344 slotoffset += sizeof(struct direntry) * (wincnt - slotcount); 345 346 /* 347 * If we get here we didn't find the entry we were looking for. But 348 * that's ok if we are creating or renaming and are at the end of 349 * the pathname and the directory hasn't been removed. 350 */ 351#ifdef MSDOSFS_DEBUG 352 printf("msdosfs_lookup(): op %d, refcnt %ld\n", 353 nameiop, dp->de_refcnt); 354 printf(" slotcount %d, slotoffset %d\n", 355 slotcount, slotoffset); 356#endif 357 if ((nameiop == CREATE || nameiop == RENAME) && 358 (flags & ISLASTCN) && dp->de_refcnt != 0) { 359 /* 360 * Access for write is interpreted as allowing 361 * creation of files in the directory. 362 */ 363 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread); 364 if (error) 365 return (error); 366 /* 367 * Return an indication of where the new directory 368 * entry should be put. 369 */ 370 dp->de_fndoffset = slotoffset; 371 dp->de_fndcnt = wincnt - 1; 372 373 /* 374 * We return with the directory locked, so that 375 * the parameters we set up above will still be 376 * valid if we actually decide to do a direnter(). 377 * We return ni_vp == NULL to indicate that the entry 378 * does not currently exist; we leave a pointer to 379 * the (locked) directory inode in ndp->ni_dvp. 380 * The pathname buffer is saved so that the name 381 * can be obtained later. 382 * 383 * NB - if the directory is unlocked, then this 384 * information cannot be used. 385 */ 386 cnp->cn_flags |= SAVENAME; 387 return (EJUSTRETURN); 388 } 389#if 0 390 /* 391 * Insert name into cache (as non-existent) if appropriate. 392 * 393 * XXX Negative caching is broken for msdosfs because the name 394 * cache doesn't understand peculiarities such as case insensitivity 395 * and 8.3 filenames. Hence, it may not invalidate all negative 396 * entries if a file with this name is later created. 397 */ 398 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) 399 cache_enter(vdp, *vpp, cnp); 400#endif 401 return (ENOENT); 402 403found: 404 /* 405 * NOTE: We still have the buffer with matched directory entry at 406 * this point. 407 */ 408 isadir = dep->deAttributes & ATTR_DIRECTORY; 409 scn = getushort(dep->deStartCluster); 410 if (FAT32(pmp)) { 411 scn |= getushort(dep->deHighClust) << 16; 412 if (scn == pmp->pm_rootdirblk) { 413 /* 414 * There should actually be 0 here. 415 * Just ignore the error. 416 */ 417 scn = MSDOSFSROOT; 418 } 419 } 420 421 if (isadir) { 422 cluster = scn; 423 if (cluster == MSDOSFSROOT) 424 blkoff = MSDOSFSROOT_OFS; 425 else 426 blkoff = 0; 427 } else if (cluster == MSDOSFSROOT) 428 blkoff = diroff; 429 430 /* 431 * Now release buf to allow deget to read the entry again. 432 * Reserving it here and giving it to deget could result 433 * in a deadlock. 434 */ 435 brelse(bp); 436 bp = 0; 437 438foundroot: 439 /* 440 * If we entered at foundroot, then we are looking for the . or .. 441 * entry of the filesystems root directory. isadir and scn were 442 * setup before jumping here. And, bp is already null. 443 */ 444 if (FAT32(pmp) && scn == MSDOSFSROOT) 445 scn = pmp->pm_rootdirblk; 446 447 if (dd_inum != NULL) { 448 *dd_inum = (uint64_t)pmp->pm_bpcluster * scn + blkoff; 449 return (0); 450 } 451 452 /* 453 * If deleting, and at end of pathname, return 454 * parameters which can be used to remove file. 455 */ 456 if (nameiop == DELETE && (flags & ISLASTCN)) { 457 /* 458 * Don't allow deleting the root. 459 */ 460 if (blkoff == MSDOSFSROOT_OFS) 461 return EROFS; /* really? XXX */ 462 463 /* 464 * Write access to directory required to delete files. 465 */ 466 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread); 467 if (error) 468 return (error); 469 470 /* 471 * Return pointer to current entry in dp->i_offset. 472 * Save directory inode pointer in ndp->ni_dvp for dirremove(). 473 */ 474 if (dp->de_StartCluster == scn && isadir) { /* "." */ 475 VREF(vdp); 476 *vpp = vdp; 477 return (0); 478 } 479 error = deget(pmp, cluster, blkoff, &tdp); 480 if (error) 481 return (error); 482 *vpp = DETOV(tdp); 483 return (0); 484 } 485 486 /* 487 * If rewriting (RENAME), return the inode and the 488 * information required to rewrite the present directory 489 * Must get inode of directory entry to verify it's a 490 * regular file, or empty directory. 491 */ 492 if (nameiop == RENAME && (flags & ISLASTCN)) { 493 if (blkoff == MSDOSFSROOT_OFS) 494 return EROFS; /* really? XXX */ 495 496 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_thread); 497 if (error) 498 return (error); 499 500 /* 501 * Careful about locking second inode. 502 * This can only occur if the target is ".". 503 */ 504 if (dp->de_StartCluster == scn && isadir) 505 return (EISDIR); 506 507 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) 508 return (error); 509 *vpp = DETOV(tdp); 510 cnp->cn_flags |= SAVENAME; 511 return (0); 512 } 513 514 /* 515 * Step through the translation in the name. We do not `vput' the 516 * directory because we may need it again if a symbolic link 517 * is relative to the current directory. Instead we save it 518 * unlocked as "pdp". We must get the target inode before unlocking 519 * the directory to insure that the inode will not be removed 520 * before we get it. We prevent deadlock by always fetching 521 * inodes from the root, moving down the directory tree. Thus 522 * when following backward pointers ".." we must unlock the 523 * parent directory before getting the requested directory. 524 */ 525 pdp = vdp; 526 if (flags & ISDOTDOT) { 527 error = msdosfs_deget_dotdot(pdp, cluster, blkoff, vpp); 528 if (error) 529 return (error); 530 /* 531 * Recheck that ".." still points to the inode we 532 * looked up before pdp lock was dropped. 533 */ 534 error = msdosfs_lookup_(pdp, NULL, cnp, &inode1); 535 if (error) { 536 vput(*vpp); 537 return (error); 538 } 539 if (VTODE(*vpp)->de_inode != inode1) { 540 vput(*vpp); 541 goto restart; 542 } 543 } else if (dp->de_StartCluster == scn && isadir) { 544 VREF(vdp); /* we want ourself, ie "." */ 545 *vpp = vdp; 546 } else { 547 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) 548 return (error); 549 *vpp = DETOV(tdp); 550 } 551 552 /* 553 * Insert name into cache if appropriate. 554 */ 555 if (cnp->cn_flags & MAKEENTRY) 556 cache_enter(vdp, *vpp, cnp); 557 return (0); 558} 559 560static int 561msdosfs_deget_dotdot(struct vnode *vp, u_long cluster, int blkoff, 562 struct vnode **rvp) 563{ 564 struct mount *mp; 565 struct msdosfsmount *pmp; 566 struct denode *rdp; 567 int ltype, error; 568 569 mp = vp->v_mount; 570 pmp = VFSTOMSDOSFS(mp); 571 ltype = VOP_ISLOCKED(vp); 572 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 573 ("msdosfs_deget_dotdot: vp not locked")); 574 575 error = vfs_busy(mp, MBF_NOWAIT); 576 if (error != 0) { 577 vfs_ref(mp); 578 VOP_UNLOCK(vp, 0); 579 error = vfs_busy(mp, 0); 580 vn_lock(vp, ltype | LK_RETRY); 581 vfs_rel(mp); 582 if (error != 0) 583 return (ENOENT); 584 if (vp->v_iflag & VI_DOOMED) { 585 vfs_unbusy(mp); 586 return (ENOENT); 587 } 588 } 589 VOP_UNLOCK(vp, 0); 590 error = deget(pmp, cluster, blkoff, &rdp); 591 vfs_unbusy(mp); 592 if (error == 0) 593 *rvp = DETOV(rdp); 594 vn_lock(vp, ltype | LK_RETRY); 595 if (vp->v_iflag & VI_DOOMED) { 596 if (error == 0) 597 vput(*rvp); 598 error = ENOENT; 599 } 600 return (error); 601} 602 603/* 604 * dep - directory entry to copy into the directory 605 * ddep - directory to add to 606 * depp - return the address of the denode for the created directory entry 607 * if depp != 0 608 * cnp - componentname needed for Win95 long filenames 609 */ 610int 611createde(dep, ddep, depp, cnp) 612 struct denode *dep; 613 struct denode *ddep; 614 struct denode **depp; 615 struct componentname *cnp; 616{ 617 int error; 618 u_long dirclust, diroffset; 619 struct direntry *ndep; 620 struct msdosfsmount *pmp = ddep->de_pmp; 621 struct buf *bp; 622 daddr_t bn; 623 int blsize; 624 625#ifdef MSDOSFS_DEBUG 626 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n", 627 dep, ddep, depp, cnp); 628#endif 629 630 /* 631 * If no space left in the directory then allocate another cluster 632 * and chain it onto the end of the file. There is one exception 633 * to this. That is, if the root directory has no more space it 634 * can NOT be expanded. extendfile() checks for and fails attempts 635 * to extend the root directory. We just return an error in that 636 * case. 637 */ 638 if (ddep->de_fndoffset >= ddep->de_FileSize) { 639 diroffset = ddep->de_fndoffset + sizeof(struct direntry) 640 - ddep->de_FileSize; 641 dirclust = de_clcount(pmp, diroffset); 642 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR); 643 if (error) { 644 (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED, NULL); 645 return error; 646 } 647 648 /* 649 * Update the size of the directory 650 */ 651 ddep->de_FileSize += de_cn2off(pmp, dirclust); 652 } 653 654 /* 655 * We just read in the cluster with space. Copy the new directory 656 * entry in. Then write it to disk. NOTE: DOS directories 657 * do not get smaller as clusters are emptied. 658 */ 659 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset), 660 &bn, &dirclust, &blsize); 661 if (error) 662 return error; 663 diroffset = ddep->de_fndoffset; 664 if (dirclust != MSDOSFSROOT) 665 diroffset &= pmp->pm_crbomask; 666 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) { 667 brelse(bp); 668 return error; 669 } 670 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 671 672 DE_EXTERNALIZE(ndep, dep); 673 674 /* 675 * Now write the Win95 long name 676 */ 677 if (ddep->de_fndcnt > 0) { 678 u_int8_t chksum = winChksum(ndep->deName); 679 const u_char *un = (const u_char *)cnp->cn_nameptr; 680 int unlen = cnp->cn_namelen; 681 int cnt = 1; 682 683 while (--ddep->de_fndcnt >= 0) { 684 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) { 685 if (DETOV(ddep)->v_mount->mnt_flag & MNT_ASYNC) 686 bdwrite(bp); 687 else if ((error = bwrite(bp)) != 0) 688 return error; 689 690 ddep->de_fndoffset -= sizeof(struct direntry); 691 error = pcbmap(ddep, 692 de_cluster(pmp, 693 ddep->de_fndoffset), 694 &bn, 0, &blsize); 695 if (error) 696 return error; 697 698 error = bread(pmp->pm_devvp, bn, blsize, 699 NOCRED, &bp); 700 if (error) { 701 brelse(bp); 702 return error; 703 } 704 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 705 } else { 706 ndep--; 707 ddep->de_fndoffset -= sizeof(struct direntry); 708 } 709 if (!unix2winfn(un, unlen, (struct winentry *)ndep, 710 cnt++, chksum, pmp)) 711 break; 712 } 713 } 714 715 if (DETOV(ddep)->v_mount->mnt_flag & MNT_ASYNC) 716 bdwrite(bp); 717 else if ((error = bwrite(bp)) != 0) 718 return error; 719 720 /* 721 * If they want us to return with the denode gotten. 722 */ 723 if (depp) { 724 if (dep->de_Attributes & ATTR_DIRECTORY) { 725 dirclust = dep->de_StartCluster; 726 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk) 727 dirclust = MSDOSFSROOT; 728 if (dirclust == MSDOSFSROOT) 729 diroffset = MSDOSFSROOT_OFS; 730 else 731 diroffset = 0; 732 } 733 return deget(pmp, dirclust, diroffset, depp); 734 } 735 736 return 0; 737} 738 739/* 740 * Be sure a directory is empty except for "." and "..". Return 1 if empty, 741 * return 0 if not empty or error. 742 */ 743int 744dosdirempty(dep) 745 struct denode *dep; 746{ 747 int blsize; 748 int error; 749 u_long cn; 750 daddr_t bn; 751 struct buf *bp; 752 struct msdosfsmount *pmp = dep->de_pmp; 753 struct direntry *dentp; 754 755 /* 756 * Since the filesize field in directory entries for a directory is 757 * zero, we just have to feel our way through the directory until 758 * we hit end of file. 759 */ 760 for (cn = 0;; cn++) { 761 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 762 if (error == E2BIG) 763 return (1); /* it's empty */ 764 return (0); 765 } 766 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 767 if (error) { 768 brelse(bp); 769 return (0); 770 } 771 for (dentp = (struct direntry *)bp->b_data; 772 (char *)dentp < bp->b_data + blsize; 773 dentp++) { 774 if (dentp->deName[0] != SLOT_DELETED && 775 (dentp->deAttributes & ATTR_VOLUME) == 0) { 776 /* 777 * In dos directories an entry whose name 778 * starts with SLOT_EMPTY (0) starts the 779 * beginning of the unused part of the 780 * directory, so we can just return that it 781 * is empty. 782 */ 783 if (dentp->deName[0] == SLOT_EMPTY) { 784 brelse(bp); 785 return (1); 786 } 787 /* 788 * Any names other than "." and ".." in a 789 * directory mean it is not empty. 790 */ 791 if (bcmp(dentp->deName, ". ", 11) && 792 bcmp(dentp->deName, ".. ", 11)) { 793 brelse(bp); 794#ifdef MSDOSFS_DEBUG 795 printf("dosdirempty(): entry found %02x, %02x\n", 796 dentp->deName[0], dentp->deName[1]); 797#endif 798 return (0); /* not empty */ 799 } 800 } 801 } 802 brelse(bp); 803 } 804 /* NOTREACHED */ 805} 806 807/* 808 * Check to see if the directory described by target is in some 809 * subdirectory of source. This prevents something like the following from 810 * succeeding and leaving a bunch or files and directories orphaned. mv 811 * /a/b/c /a/b/c/d/e/f Where c and f are directories. 812 * 813 * source - the inode for /a/b/c 814 * target - the inode for /a/b/c/d/e/f 815 * 816 * Returns 0 if target is NOT a subdirectory of source. 817 * Otherwise returns a non-zero error number. 818 * The target inode is always unlocked on return. 819 */ 820int 821doscheckpath(source, target) 822 struct denode *source; 823 struct denode *target; 824{ 825 daddr_t scn; 826 struct msdosfsmount *pmp; 827 struct direntry *ep; 828 struct denode *dep; 829 struct buf *bp = NULL; 830 int error = 0; 831 832 dep = target; 833 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 || 834 (source->de_Attributes & ATTR_DIRECTORY) == 0) { 835 error = ENOTDIR; 836 goto out; 837 } 838 if (dep->de_StartCluster == source->de_StartCluster) { 839 error = EEXIST; 840 goto out; 841 } 842 if (dep->de_StartCluster == MSDOSFSROOT) 843 goto out; 844 pmp = dep->de_pmp; 845#ifdef DIAGNOSTIC 846 if (pmp != source->de_pmp) 847 panic("doscheckpath: source and target on different filesystems"); 848#endif 849 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk) 850 goto out; 851 852 for (;;) { 853 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) { 854 error = ENOTDIR; 855 break; 856 } 857 scn = dep->de_StartCluster; 858 error = bread(pmp->pm_devvp, cntobn(pmp, scn), 859 pmp->pm_bpcluster, NOCRED, &bp); 860 if (error) 861 break; 862 863 ep = (struct direntry *) bp->b_data + 1; 864 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 || 865 bcmp(ep->deName, ".. ", 11) != 0) { 866 error = ENOTDIR; 867 break; 868 } 869 scn = getushort(ep->deStartCluster); 870 if (FAT32(pmp)) 871 scn |= getushort(ep->deHighClust) << 16; 872 873 if (scn == source->de_StartCluster) { 874 error = EINVAL; 875 break; 876 } 877 if (scn == MSDOSFSROOT) 878 break; 879 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) { 880 /* 881 * scn should be 0 in this case, 882 * but we silently ignore the error. 883 */ 884 break; 885 } 886 887 vput(DETOV(dep)); 888 brelse(bp); 889 bp = NULL; 890 /* NOTE: deget() clears dep on error */ 891 if ((error = deget(pmp, scn, 0, &dep)) != 0) 892 break; 893 } 894out:; 895 if (bp) 896 brelse(bp); 897 if (error == ENOTDIR) 898 printf("doscheckpath(): .. not a directory?\n"); 899 if (dep != NULL) 900 vput(DETOV(dep)); 901 return (error); 902} 903 904/* 905 * Read in the disk block containing the directory entry (dirclu, dirofs) 906 * and return the address of the buf header, and the address of the 907 * directory entry within the block. 908 */ 909int 910readep(pmp, dirclust, diroffset, bpp, epp) 911 struct msdosfsmount *pmp; 912 u_long dirclust, diroffset; 913 struct buf **bpp; 914 struct direntry **epp; 915{ 916 int error; 917 daddr_t bn; 918 int blsize; 919 920 blsize = pmp->pm_bpcluster; 921 if (dirclust == MSDOSFSROOT 922 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize) 923 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask; 924 bn = detobn(pmp, dirclust, diroffset); 925 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) { 926 brelse(*bpp); 927 *bpp = NULL; 928 return (error); 929 } 930 if (epp) 931 *epp = bptoep(pmp, *bpp, diroffset); 932 return (0); 933} 934 935/* 936 * Read in the disk block containing the directory entry dep came from and 937 * return the address of the buf header, and the address of the directory 938 * entry within the block. 939 */ 940int 941readde(dep, bpp, epp) 942 struct denode *dep; 943 struct buf **bpp; 944 struct direntry **epp; 945{ 946 947 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset, 948 bpp, epp)); 949} 950 951/* 952 * Remove a directory entry. At this point the file represented by the 953 * directory entry to be removed is still full length until noone has it 954 * open. When the file no longer being used msdosfs_inactive() is called 955 * and will truncate the file to 0 length. When the vnode containing the 956 * denode is needed for some other purpose by VFS it will call 957 * msdosfs_reclaim() which will remove the denode from the denode cache. 958 */ 959int 960removede(pdep, dep) 961 struct denode *pdep; /* directory where the entry is removed */ 962 struct denode *dep; /* file to be removed */ 963{ 964 int error; 965 struct direntry *ep; 966 struct buf *bp; 967 daddr_t bn; 968 int blsize; 969 struct msdosfsmount *pmp = pdep->de_pmp; 970 u_long offset = pdep->de_fndoffset; 971 972#ifdef MSDOSFS_DEBUG 973 printf("removede(): filename %s, dep %p, offset %08lx\n", 974 dep->de_Name, dep, offset); 975#endif 976 977 dep->de_refcnt--; 978 offset += sizeof(struct direntry); 979 do { 980 offset -= sizeof(struct direntry); 981 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize); 982 if (error) 983 return error; 984 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 985 if (error) { 986 brelse(bp); 987 return error; 988 } 989 ep = bptoep(pmp, bp, offset); 990 /* 991 * Check whether, if we came here the second time, i.e. 992 * when underflowing into the previous block, the last 993 * entry in this block is a longfilename entry, too. 994 */ 995 if (ep->deAttributes != ATTR_WIN95 996 && offset != pdep->de_fndoffset) { 997 brelse(bp); 998 break; 999 } 1000 offset += sizeof(struct direntry); 1001 while (1) { 1002 /* 1003 * We are a bit agressive here in that we delete any Win95 1004 * entries preceding this entry, not just the ones we "own". 1005 * Since these presumably aren't valid anyway, 1006 * there should be no harm. 1007 */ 1008 offset -= sizeof(struct direntry); 1009 ep--->deName[0] = SLOT_DELETED; 1010 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) 1011 || !(offset & pmp->pm_crbomask) 1012 || ep->deAttributes != ATTR_WIN95) 1013 break; 1014 } 1015 if (DETOV(pdep)->v_mount->mnt_flag & MNT_ASYNC) 1016 bdwrite(bp); 1017 else if ((error = bwrite(bp)) != 0) 1018 return error; 1019 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95) 1020 && !(offset & pmp->pm_crbomask) 1021 && offset); 1022 return 0; 1023} 1024 1025/* 1026 * Create a unique DOS name in dvp 1027 */ 1028int 1029uniqdosname(dep, cnp, cp) 1030 struct denode *dep; 1031 struct componentname *cnp; 1032 u_char *cp; 1033{ 1034 struct msdosfsmount *pmp = dep->de_pmp; 1035 struct direntry *dentp; 1036 int gen; 1037 int blsize; 1038 u_long cn; 1039 daddr_t bn; 1040 struct buf *bp; 1041 int error; 1042 1043 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) 1044 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 1045 cnp->cn_namelen, 0, pmp) ? 0 : EINVAL); 1046 1047 for (gen = 1;; gen++) { 1048 /* 1049 * Generate DOS name with generation number 1050 */ 1051 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 1052 cnp->cn_namelen, gen, pmp)) 1053 return gen == 1 ? EINVAL : EEXIST; 1054 1055 /* 1056 * Now look for a dir entry with this exact name 1057 */ 1058 for (cn = error = 0; !error; cn++) { 1059 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 1060 if (error == E2BIG) /* EOF reached and not found */ 1061 return 0; 1062 return error; 1063 } 1064 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 1065 if (error) { 1066 brelse(bp); 1067 return error; 1068 } 1069 for (dentp = (struct direntry *)bp->b_data; 1070 (char *)dentp < bp->b_data + blsize; 1071 dentp++) { 1072 if (dentp->deName[0] == SLOT_EMPTY) { 1073 /* 1074 * Last used entry and not found 1075 */ 1076 brelse(bp); 1077 return 0; 1078 } 1079 /* 1080 * Ignore volume labels and Win95 entries 1081 */ 1082 if (dentp->deAttributes & ATTR_VOLUME) 1083 continue; 1084 if (!bcmp(dentp->deName, cp, 11)) { 1085 error = EEXIST; 1086 break; 1087 } 1088 } 1089 brelse(bp); 1090 } 1091 } 1092} 1093 1094/* 1095 * Find any Win'95 long filename entry in directory dep 1096 */ 1097int 1098findwin95(dep) 1099 struct denode *dep; 1100{ 1101 struct msdosfsmount *pmp = dep->de_pmp; 1102 struct direntry *dentp; 1103 int blsize, win95; 1104 u_long cn; 1105 daddr_t bn; 1106 struct buf *bp; 1107 1108 win95 = 1; 1109 /* 1110 * Read through the directory looking for Win'95 entries 1111 * Note: Error currently handled just as EOF XXX 1112 */ 1113 for (cn = 0;; cn++) { 1114 if (pcbmap(dep, cn, &bn, 0, &blsize)) 1115 return (win95); 1116 if (bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) { 1117 brelse(bp); 1118 return (win95); 1119 } 1120 for (dentp = (struct direntry *)bp->b_data; 1121 (char *)dentp < bp->b_data + blsize; 1122 dentp++) { 1123 if (dentp->deName[0] == SLOT_EMPTY) { 1124 /* 1125 * Last used entry and not found 1126 */ 1127 brelse(bp); 1128 return (win95); 1129 } 1130 if (dentp->deName[0] == SLOT_DELETED) { 1131 /* 1132 * Ignore deleted files 1133 * Note: might be an indication of Win'95 anyway XXX 1134 */ 1135 continue; 1136 } 1137 if (dentp->deAttributes == ATTR_WIN95) { 1138 brelse(bp); 1139 return 1; 1140 } 1141 win95 = 0; 1142 } 1143 brelse(bp); 1144 } 1145} 1146