1 /* $FreeBSD: src/sys/msdosfs/msdosfs_lookup.c,v 1.30.2.1 2000/11/03 15:55:39 bp Exp $ */ 2 /* $DragonFly: src/sys/vfs/msdosfs/msdosfs_lookup.c,v 1.8 2004/03/01 06:33:21 dillon Exp $ */ 3 /* $NetBSD: msdosfs_lookup.c,v 1.37 1997/11/17 15:36:54 ws Exp $ */ 4 5 /*- 6 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank. 7 * Copyright (C) 1994, 1995, 1997 TooLs GmbH. 8 * All rights reserved. 9 * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below). 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by TooLs GmbH. 22 * 4. The name of TooLs GmbH may not be used to endorse or promote products 23 * derived from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 29 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 30 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 31 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 32 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 33 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 34 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 35 */ 36 /* 37 * Written by Paul Popelka (paulp@uts.amdahl.com) 38 * 39 * You can do anything you want with this software, just don't say you wrote 40 * it, and don't remove this notice. 41 * 42 * This software is provided "as is". 43 * 44 * The author supplies this software to be publicly redistributed on the 45 * understanding that the author is not responsible for the correct 46 * functioning of this software in any circumstances and is not liable for 47 * any damages caused by this software. 48 * 49 * October 1992 50 */ 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/buf.h> 55 #include <sys/vnode.h> 56 #include <sys/proc.h> 57 #include <sys/namei.h> 58 #include <sys/mount.h> 59 60 #include "bpb.h" 61 #include "direntry.h" 62 #include "denode.h" 63 #include "msdosfsmount.h" 64 #include "fat.h" 65 66 /* 67 * When we search a directory the blocks containing directory entries are 68 * read and examined. The directory entries contain information that would 69 * normally be in the inode of a unix filesystem. This means that some of 70 * a directory's contents may also be in memory resident denodes (sort of 71 * an inode). This can cause problems if we are searching while some other 72 * process is modifying a directory. To prevent one process from accessing 73 * incompletely modified directory information we depend upon being the 74 * sole owner of a directory block. bread/brelse provide this service. 75 * This being the case, when a process modifies a directory it must first 76 * acquire the disk block that contains the directory entry to be modified. 77 * Then update the disk block and the denode, and then write the disk block 78 * out to disk. This way disk blocks containing directory entries and in 79 * memory denode's will be in synch. 80 */ 81 int 82 msdosfs_lookup(ap) 83 struct vop_cachedlookup_args /* { 84 struct vnode *a_dvp; 85 struct vnode **a_vpp; 86 struct componentname *a_cnp; 87 } */ *ap; 88 { 89 struct vnode *vdp = ap->a_dvp; 90 struct vnode **vpp = ap->a_vpp; 91 struct componentname *cnp = ap->a_cnp; 92 daddr_t bn; 93 int error; 94 int lockparent; 95 int wantparent; 96 int slotcount; 97 int slotoffset = 0; 98 int frcn; 99 u_long cluster; 100 int blkoff; 101 int diroff; 102 int blsize; 103 int isadir; /* ~0 if found direntry is a directory */ 104 u_long scn; /* starting cluster number */ 105 struct vnode *pdp; 106 struct denode *dp; 107 struct denode *tdp; 108 struct msdosfsmount *pmp; 109 struct buf *bp = 0; 110 struct direntry *dep = NULL; 111 u_char dosfilename[12]; 112 int flags = cnp->cn_flags; 113 int nameiop = cnp->cn_nameiop; 114 struct thread *td = cnp->cn_td; 115 int unlen; 116 117 int wincnt = 1; 118 int chksum = -1; 119 int olddos = 1; 120 cnp->cn_flags &= ~CNP_PDIRUNLOCK; 121 122 #ifdef MSDOSFS_DEBUG 123 printf("msdosfs_lookup(): looking for %s\n", cnp->cn_nameptr); 124 #endif 125 dp = VTODE(vdp); 126 pmp = dp->de_pmp; 127 *vpp = NULL; 128 lockparent = flags & CNP_LOCKPARENT; 129 wantparent = flags & (CNP_LOCKPARENT | CNP_WANTPARENT); 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 /* 136 * If they are going after the . or .. entry in the root directory, 137 * they won't find it. DOS filesystems don't have them in the root 138 * directory. So, we fake it. deget() is in on this scam too. 139 */ 140 if ((vdp->v_flag & VROOT) && cnp->cn_nameptr[0] == '.' && 141 (cnp->cn_namelen == 1 || 142 (cnp->cn_namelen == 2 && cnp->cn_nameptr[1] == '.'))) { 143 isadir = ATTR_DIRECTORY; 144 scn = MSDOSFSROOT; 145 #ifdef MSDOSFS_DEBUG 146 printf("msdosfs_lookup(): looking for . or .. in root directory\n"); 147 #endif 148 cluster = MSDOSFSROOT; 149 blkoff = MSDOSFSROOT_OFS; 150 goto foundroot; 151 } 152 153 switch (unix2dosfn((const u_char *)cnp->cn_nameptr, dosfilename, 154 cnp->cn_namelen, 0, 155 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d, 156 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu)) { 157 case 0: 158 return (EINVAL); 159 case 1: 160 break; 161 case 2: 162 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr, 163 cnp->cn_namelen) + 1; 164 break; 165 case 3: 166 olddos = 0; 167 wincnt = winSlotCnt((const u_char *)cnp->cn_nameptr, 168 cnp->cn_namelen) + 1; 169 break; 170 } 171 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) { 172 wincnt = 1; 173 olddos = 1; 174 } 175 unlen = winLenFixup(cnp->cn_nameptr, cnp->cn_namelen); 176 177 /* 178 * Suppress search for slots unless creating 179 * file and at end of pathname, in which case 180 * we watch for a place to put the new file in 181 * case it doesn't already exist. 182 */ 183 slotcount = wincnt; 184 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) && 185 (flags & CNP_ISLASTCN)) 186 slotcount = 0; 187 188 #ifdef MSDOSFS_DEBUG 189 printf("msdosfs_lookup(): dos version of filename %s, length %ld\n", 190 dosfilename, cnp->cn_namelen); 191 #endif 192 /* 193 * Search the directory pointed at by vdp for the name pointed at 194 * by cnp->cn_nameptr. 195 */ 196 tdp = NULL; 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, &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; 236 237 if (slotcount < wincnt) { 238 slotcount++; 239 slotoffset = diroff; 240 } 241 if (dep->deName[0] == SLOT_EMPTY) { 242 brelse(bp); 243 goto notfound; 244 } 245 } else { 246 /* 247 * If there wasn't enough space for our winentries, 248 * forget about the empty space 249 */ 250 if (slotcount < wincnt) 251 slotcount = 0; 252 253 /* 254 * Check for Win95 long filename entry 255 */ 256 if (dep->deAttributes == ATTR_WIN95) { 257 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) 258 continue; 259 260 chksum = winChkName((const u_char *)cnp->cn_nameptr, 261 unlen, 262 (struct winentry *)dep, 263 chksum, 264 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, 265 pmp->pm_u2w, 266 pmp->pm_flags & MSDOSFSMNT_ULTABLE, 267 pmp->pm_ul); 268 continue; 269 } 270 271 /* 272 * Ignore volume labels (anywhere, not just 273 * the root directory). 274 */ 275 if (dep->deAttributes & ATTR_VOLUME) { 276 chksum = -1; 277 continue; 278 } 279 280 /* 281 * Check for a checksum or name match 282 */ 283 if (chksum != winChksum(dep->deName) 284 && (!olddos || bcmp(dosfilename, dep->deName, 11))) { 285 chksum = -1; 286 continue; 287 } 288 #ifdef MSDOSFS_DEBUG 289 printf("msdosfs_lookup(): match blkoff %d, diroff %d\n", 290 blkoff, diroff); 291 #endif 292 /* 293 * Remember where this directory 294 * entry came from for whoever did 295 * this lookup. 296 */ 297 dp->de_fndoffset = diroff; 298 dp->de_fndcnt = wincnt - 1; 299 300 goto found; 301 } 302 } /* for (blkoff = 0; .... */ 303 /* 304 * Release the buffer holding the directory cluster just 305 * searched. 306 */ 307 brelse(bp); 308 } /* for (frcn = 0; ; frcn++) */ 309 310 notfound: 311 /* 312 * We hold no disk buffers at this point. 313 */ 314 315 /* 316 * Fixup the slot description to point to the place where 317 * we might put the new DOS direntry (putting the Win95 318 * long name entries before that) 319 */ 320 if (!slotcount) { 321 slotcount = 1; 322 slotoffset = diroff; 323 } 324 if (wincnt > slotcount) 325 slotoffset += sizeof(struct direntry) * (wincnt - slotcount); 326 327 /* 328 * If we get here we didn't find the entry we were looking for. But 329 * that's ok if we are creating or renaming and are at the end of 330 * the pathname and the directory hasn't been removed. 331 */ 332 #ifdef MSDOSFS_DEBUG 333 printf("msdosfs_lookup(): op %d, refcnt %ld\n", 334 nameiop, dp->de_refcnt); 335 printf(" slotcount %d, slotoffset %d\n", 336 slotcount, slotoffset); 337 #endif 338 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) && 339 (flags & CNP_ISLASTCN) && dp->de_refcnt != 0) { 340 /* 341 * Access for write is interpreted as allowing 342 * creation of files in the directory. 343 */ 344 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_td); 345 if (error) 346 return (error); 347 /* 348 * Return an indication of where the new directory 349 * entry should be put. 350 */ 351 dp->de_fndoffset = slotoffset; 352 dp->de_fndcnt = wincnt - 1; 353 354 /* 355 * We return with the directory locked, so that 356 * the parameters we set up above will still be 357 * valid if we actually decide to do a direnter(). 358 * We return ni_vp == NULL to indicate that the entry 359 * does not currently exist; we leave a pointer to 360 * the (locked) directory inode in ndp->ni_dvp. 361 * The pathname buffer is saved so that the name 362 * can be obtained later. 363 * 364 * NB - if the directory is unlocked, then this 365 * information cannot be used. 366 */ 367 cnp->cn_flags |= CNP_SAVENAME; 368 if (!lockparent) { 369 VOP_UNLOCK(vdp, NULL, 0, td); 370 cnp->cn_flags |= CNP_PDIRUNLOCK; 371 } 372 return (EJUSTRETURN); 373 } 374 /* 375 * Insert name into cache (as non-existent) if appropriate. 376 */ 377 if ((cnp->cn_flags & CNP_MAKEENTRY) && nameiop != NAMEI_CREATE) 378 cache_enter(vdp, NCPNULL, *vpp, cnp); 379 return (ENOENT); 380 381 found: 382 /* 383 * NOTE: We still have the buffer with matched directory entry at 384 * this point. 385 */ 386 isadir = dep->deAttributes & ATTR_DIRECTORY; 387 scn = getushort(dep->deStartCluster); 388 if (FAT32(pmp)) { 389 scn |= getushort(dep->deHighClust) << 16; 390 if (scn == pmp->pm_rootdirblk) { 391 /* 392 * There should actually be 0 here. 393 * Just ignore the error. 394 */ 395 scn = MSDOSFSROOT; 396 } 397 } 398 399 if (isadir) { 400 cluster = scn; 401 if (cluster == MSDOSFSROOT) 402 blkoff = MSDOSFSROOT_OFS; 403 else 404 blkoff = 0; 405 } else if (cluster == MSDOSFSROOT) 406 blkoff = diroff; 407 408 /* 409 * Now release buf to allow deget to read the entry again. 410 * Reserving it here and giving it to deget could result 411 * in a deadlock. 412 */ 413 brelse(bp); 414 bp = 0; 415 416 foundroot: 417 /* 418 * If we entered at foundroot, then we are looking for the . or .. 419 * entry of the filesystems root directory. isadir and scn were 420 * setup before jumping here. And, bp is already null. 421 */ 422 if (FAT32(pmp) && scn == MSDOSFSROOT) 423 scn = pmp->pm_rootdirblk; 424 425 /* 426 * If deleting, and at end of pathname, return 427 * parameters which can be used to remove file. 428 * If the wantparent flag isn't set, we return only 429 * the directory (in ndp->ni_dvp), otherwise we go 430 * on and lock the inode, being careful with ".". 431 */ 432 if (nameiop == NAMEI_DELETE && (flags & CNP_ISLASTCN)) { 433 /* 434 * Don't allow deleting the root. 435 */ 436 if (blkoff == MSDOSFSROOT_OFS) 437 return EROFS; /* really? XXX */ 438 439 /* 440 * Write access to directory required to delete files. 441 */ 442 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_td); 443 if (error) 444 return (error); 445 446 /* 447 * Return pointer to current entry in dp->i_offset. 448 * Save directory inode pointer in ndp->ni_dvp for dirremove(). 449 */ 450 if (dp->de_StartCluster == scn && isadir) { /* "." */ 451 VREF(vdp); 452 *vpp = vdp; 453 return (0); 454 } 455 error = deget(pmp, cluster, blkoff, &tdp); 456 if (error) 457 return (error); 458 *vpp = DETOV(tdp); 459 if (!lockparent) { 460 VOP_UNLOCK(vdp, NULL, 0, td); 461 cnp->cn_flags |= CNP_PDIRUNLOCK; 462 } 463 return (0); 464 } 465 466 /* 467 * If rewriting (RENAME), return the inode and the 468 * information required to rewrite the present directory 469 * Must get inode of directory entry to verify it's a 470 * regular file, or empty directory. 471 */ 472 if (nameiop == NAMEI_RENAME && wantparent && 473 (flags & CNP_ISLASTCN)) { 474 if (blkoff == MSDOSFSROOT_OFS) 475 return EROFS; /* really? XXX */ 476 477 error = VOP_ACCESS(vdp, VWRITE, cnp->cn_cred, cnp->cn_td); 478 if (error) 479 return (error); 480 481 /* 482 * Careful about locking second inode. 483 * This can only occur if the target is ".". 484 */ 485 if (dp->de_StartCluster == scn && isadir) 486 return (EISDIR); 487 488 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) 489 return (error); 490 *vpp = DETOV(tdp); 491 cnp->cn_flags |= CNP_SAVENAME; 492 if (!lockparent) { 493 VOP_UNLOCK(vdp, NULL, 0, td); 494 cnp->cn_flags |= CNP_PDIRUNLOCK; 495 } 496 return (0); 497 } 498 499 /* 500 * Step through the translation in the name. We do not `vput' the 501 * directory because we may need it again if a symbolic link 502 * is relative to the current directory. Instead we save it 503 * unlocked as "pdp". We must get the target inode before unlocking 504 * the directory to insure that the inode will not be removed 505 * before we get it. We prevent deadlock by always fetching 506 * inodes from the root, moving down the directory tree. Thus 507 * when following backward pointers ".." we must unlock the 508 * parent directory before getting the requested directory. 509 * There is a potential race condition here if both the current 510 * and parent directories are removed before the VFS_VGET for the 511 * inode associated with ".." returns. We hope that this occurs 512 * infrequently since we cannot avoid this race condition without 513 * implementing a sophisticated deadlock detection algorithm. 514 * Note also that this simple deadlock detection scheme will not 515 * work if the file system has any hard links other than ".." 516 * that point backwards in the directory structure. 517 */ 518 pdp = vdp; 519 if (flags & CNP_ISDOTDOT) { 520 VOP_UNLOCK(pdp, NULL, 0, td); 521 cnp->cn_flags |= CNP_PDIRUNLOCK; 522 error = deget(pmp, cluster, blkoff, &tdp); 523 if (error) { 524 vn_lock(pdp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 525 cnp->cn_flags &= ~CNP_PDIRUNLOCK; 526 return (error); 527 } 528 if (lockparent && (flags & CNP_ISLASTCN)) { 529 error = vn_lock(pdp, NULL, LK_EXCLUSIVE, td); 530 if (error) { 531 vput(DETOV(tdp)); 532 return (error); 533 } 534 cnp->cn_flags &= ~CNP_PDIRUNLOCK; 535 } 536 *vpp = DETOV(tdp); 537 } else if (dp->de_StartCluster == scn && isadir) { 538 VREF(vdp); /* we want ourself, ie "." */ 539 *vpp = vdp; 540 } else { 541 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) 542 return (error); 543 if (!lockparent || !(flags & CNP_ISLASTCN)) { 544 VOP_UNLOCK(pdp, NULL, 0, td); 545 cnp->cn_flags |= CNP_PDIRUNLOCK; 546 } 547 *vpp = DETOV(tdp); 548 } 549 550 /* 551 * Insert name into cache if appropriate. 552 */ 553 if (cnp->cn_flags & CNP_MAKEENTRY) 554 cache_enter(vdp, NCPNULL, *vpp, cnp); 555 return (0); 556 } 557 558 /* 559 * dep - directory entry to copy into the directory 560 * ddep - directory to add to 561 * depp - return the address of the denode for the created directory entry 562 * if depp != 0 563 * cnp - componentname needed for Win95 long filenames 564 */ 565 int 566 createde(dep, ddep, depp, cnp) 567 struct denode *dep; 568 struct denode *ddep; 569 struct denode **depp; 570 struct componentname *cnp; 571 { 572 int error; 573 u_long dirclust, diroffset; 574 struct direntry *ndep; 575 struct msdosfsmount *pmp = ddep->de_pmp; 576 struct buf *bp; 577 daddr_t bn; 578 int blsize; 579 580 #ifdef MSDOSFS_DEBUG 581 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n", 582 dep, ddep, depp, cnp); 583 #endif 584 585 /* 586 * If no space left in the directory then allocate another cluster 587 * and chain it onto the end of the file. There is one exception 588 * to this. That is, if the root directory has no more space it 589 * can NOT be expanded. extendfile() checks for and fails attempts 590 * to extend the root directory. We just return an error in that 591 * case. 592 */ 593 if (ddep->de_fndoffset >= ddep->de_FileSize) { 594 diroffset = ddep->de_fndoffset + sizeof(struct direntry) 595 - ddep->de_FileSize; 596 dirclust = de_clcount(pmp, diroffset); 597 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR); 598 if (error) { 599 (void)detrunc(ddep, ddep->de_FileSize, 0, NULL); 600 return error; 601 } 602 603 /* 604 * Update the size of the directory 605 */ 606 ddep->de_FileSize += de_cn2off(pmp, dirclust); 607 } 608 609 /* 610 * We just read in the cluster with space. Copy the new directory 611 * entry in. Then write it to disk. NOTE: DOS directories 612 * do not get smaller as clusters are emptied. 613 */ 614 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset), 615 &bn, &dirclust, &blsize); 616 if (error) 617 return error; 618 diroffset = ddep->de_fndoffset; 619 if (dirclust != MSDOSFSROOT) 620 diroffset &= pmp->pm_crbomask; 621 if ((error = bread(pmp->pm_devvp, bn, blsize, &bp)) != 0) { 622 brelse(bp); 623 return error; 624 } 625 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 626 627 DE_EXTERNALIZE(ndep, dep); 628 629 /* 630 * Now write the Win95 long name 631 */ 632 if (ddep->de_fndcnt > 0) { 633 u_int8_t chksum = winChksum(ndep->deName); 634 const u_char *un = (const u_char *)cnp->cn_nameptr; 635 int unlen = cnp->cn_namelen; 636 int cnt = 1; 637 638 while (--ddep->de_fndcnt >= 0) { 639 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) { 640 if ((error = bwrite(bp)) != 0) 641 return error; 642 643 ddep->de_fndoffset -= sizeof(struct direntry); 644 error = pcbmap(ddep, 645 de_cluster(pmp, 646 ddep->de_fndoffset), 647 &bn, 0, &blsize); 648 if (error) 649 return error; 650 651 error = bread(pmp->pm_devvp, bn, blsize, &bp); 652 if (error) { 653 brelse(bp); 654 return error; 655 } 656 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 657 } else { 658 ndep--; 659 ddep->de_fndoffset -= sizeof(struct direntry); 660 } 661 if (!unix2winfn(un, unlen, (struct winentry *)ndep, 662 cnt++, chksum, 663 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, 664 pmp->pm_u2w)) 665 break; 666 } 667 } 668 669 if ((error = bwrite(bp)) != 0) 670 return error; 671 672 /* 673 * If they want us to return with the denode gotten. 674 */ 675 if (depp) { 676 if (dep->de_Attributes & ATTR_DIRECTORY) { 677 dirclust = dep->de_StartCluster; 678 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk) 679 dirclust = MSDOSFSROOT; 680 if (dirclust == MSDOSFSROOT) 681 diroffset = MSDOSFSROOT_OFS; 682 else 683 diroffset = 0; 684 } 685 return deget(pmp, dirclust, diroffset, depp); 686 } 687 688 return 0; 689 } 690 691 /* 692 * Be sure a directory is empty except for "." and "..". Return 1 if empty, 693 * return 0 if not empty or error. 694 */ 695 int 696 dosdirempty(dep) 697 struct denode *dep; 698 { 699 int blsize; 700 int error; 701 u_long cn; 702 daddr_t bn; 703 struct buf *bp; 704 struct msdosfsmount *pmp = dep->de_pmp; 705 struct direntry *dentp; 706 707 /* 708 * Since the filesize field in directory entries for a directory is 709 * zero, we just have to feel our way through the directory until 710 * we hit end of file. 711 */ 712 for (cn = 0;; cn++) { 713 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 714 if (error == E2BIG) 715 return (1); /* it's empty */ 716 return (0); 717 } 718 error = bread(pmp->pm_devvp, bn, blsize, &bp); 719 if (error) { 720 brelse(bp); 721 return (0); 722 } 723 for (dentp = (struct direntry *)bp->b_data; 724 (char *)dentp < bp->b_data + blsize; 725 dentp++) { 726 if (dentp->deName[0] != SLOT_DELETED && 727 (dentp->deAttributes & ATTR_VOLUME) == 0) { 728 /* 729 * In dos directories an entry whose name 730 * starts with SLOT_EMPTY (0) starts the 731 * beginning of the unused part of the 732 * directory, so we can just return that it 733 * is empty. 734 */ 735 if (dentp->deName[0] == SLOT_EMPTY) { 736 brelse(bp); 737 return (1); 738 } 739 /* 740 * Any names other than "." and ".." in a 741 * directory mean it is not empty. 742 */ 743 if (bcmp(dentp->deName, ". ", 11) && 744 bcmp(dentp->deName, ".. ", 11)) { 745 brelse(bp); 746 #ifdef MSDOSFS_DEBUG 747 printf("dosdirempty(): entry found %02x, %02x\n", 748 dentp->deName[0], dentp->deName[1]); 749 #endif 750 return (0); /* not empty */ 751 } 752 } 753 } 754 brelse(bp); 755 } 756 /* NOTREACHED */ 757 } 758 759 /* 760 * Check to see if the directory described by target is in some 761 * subdirectory of source. This prevents something like the following from 762 * succeeding and leaving a bunch or files and directories orphaned. mv 763 * /a/b/c /a/b/c/d/e/f Where c and f are directories. 764 * 765 * source - the inode for /a/b/c 766 * target - the inode for /a/b/c/d/e/f 767 * 768 * Returns 0 if target is NOT a subdirectory of source. 769 * Otherwise returns a non-zero error number. 770 * The target inode is always unlocked on return. 771 */ 772 int 773 doscheckpath(source, target) 774 struct denode *source; 775 struct denode *target; 776 { 777 daddr_t scn; 778 struct msdosfsmount *pmp; 779 struct direntry *ep; 780 struct denode *dep; 781 struct buf *bp = NULL; 782 int error = 0; 783 784 dep = target; 785 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 || 786 (source->de_Attributes & ATTR_DIRECTORY) == 0) { 787 error = ENOTDIR; 788 goto out; 789 } 790 if (dep->de_StartCluster == source->de_StartCluster) { 791 error = EEXIST; 792 goto out; 793 } 794 if (dep->de_StartCluster == MSDOSFSROOT) 795 goto out; 796 pmp = dep->de_pmp; 797 #ifdef DIAGNOSTIC 798 if (pmp != source->de_pmp) 799 panic("doscheckpath: source and target on different filesystems"); 800 #endif 801 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk) 802 goto out; 803 804 for (;;) { 805 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) { 806 error = ENOTDIR; 807 break; 808 } 809 scn = dep->de_StartCluster; 810 error = bread(pmp->pm_devvp, cntobn(pmp, scn), 811 pmp->pm_bpcluster, &bp); 812 if (error) 813 break; 814 815 ep = (struct direntry *) bp->b_data + 1; 816 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 || 817 bcmp(ep->deName, ".. ", 11) != 0) { 818 error = ENOTDIR; 819 break; 820 } 821 scn = getushort(ep->deStartCluster); 822 if (FAT32(pmp)) 823 scn |= getushort(ep->deHighClust) << 16; 824 825 if (scn == source->de_StartCluster) { 826 error = EINVAL; 827 break; 828 } 829 if (scn == MSDOSFSROOT) 830 break; 831 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) { 832 /* 833 * scn should be 0 in this case, 834 * but we silently ignore the error. 835 */ 836 break; 837 } 838 839 vput(DETOV(dep)); 840 brelse(bp); 841 bp = NULL; 842 /* NOTE: deget() clears dep on error */ 843 if ((error = deget(pmp, scn, 0, &dep)) != 0) 844 break; 845 } 846 out:; 847 if (bp) 848 brelse(bp); 849 if (error == ENOTDIR) 850 printf("doscheckpath(): .. not a directory?\n"); 851 if (dep != NULL) 852 vput(DETOV(dep)); 853 return (error); 854 } 855 856 /* 857 * Read in the disk block containing the directory entry (dirclu, dirofs) 858 * and return the address of the buf header, and the address of the 859 * directory entry within the block. 860 */ 861 int 862 readep(pmp, dirclust, diroffset, bpp, epp) 863 struct msdosfsmount *pmp; 864 u_long dirclust, diroffset; 865 struct buf **bpp; 866 struct direntry **epp; 867 { 868 int error; 869 daddr_t bn; 870 int blsize; 871 872 blsize = pmp->pm_bpcluster; 873 if (dirclust == MSDOSFSROOT 874 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize) 875 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask; 876 bn = detobn(pmp, dirclust, diroffset); 877 if ((error = bread(pmp->pm_devvp, bn, blsize, bpp)) != 0) { 878 brelse(*bpp); 879 *bpp = NULL; 880 return (error); 881 } 882 if (epp) 883 *epp = bptoep(pmp, *bpp, diroffset); 884 return (0); 885 } 886 887 /* 888 * Read in the disk block containing the directory entry dep came from and 889 * return the address of the buf header, and the address of the directory 890 * entry within the block. 891 */ 892 int 893 readde(dep, bpp, epp) 894 struct denode *dep; 895 struct buf **bpp; 896 struct direntry **epp; 897 { 898 899 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset, 900 bpp, epp)); 901 } 902 903 /* 904 * Remove a directory entry. At this point the file represented by the 905 * directory entry to be removed is still full length until noone has it 906 * open. When the file no longer being used msdosfs_inactive() is called 907 * and will truncate the file to 0 length. When the vnode containing the 908 * denode is needed for some other purpose by VFS it will call 909 * msdosfs_reclaim() which will remove the denode from the denode cache. 910 */ 911 int 912 removede(pdep, dep) 913 struct denode *pdep; /* directory where the entry is removed */ 914 struct denode *dep; /* file to be removed */ 915 { 916 int error; 917 struct direntry *ep; 918 struct buf *bp; 919 daddr_t bn; 920 int blsize; 921 struct msdosfsmount *pmp = pdep->de_pmp; 922 u_long offset = pdep->de_fndoffset; 923 924 #ifdef MSDOSFS_DEBUG 925 printf("removede(): filename %s, dep %p, offset %08lx\n", 926 dep->de_Name, dep, offset); 927 #endif 928 929 dep->de_refcnt--; 930 offset += sizeof(struct direntry); 931 do { 932 offset -= sizeof(struct direntry); 933 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize); 934 if (error) 935 return error; 936 error = bread(pmp->pm_devvp, bn, blsize, &bp); 937 if (error) { 938 brelse(bp); 939 return error; 940 } 941 ep = bptoep(pmp, bp, offset); 942 /* 943 * Check whether, if we came here the second time, i.e. 944 * when underflowing into the previous block, the last 945 * entry in this block is a longfilename entry, too. 946 */ 947 if (ep->deAttributes != ATTR_WIN95 948 && offset != pdep->de_fndoffset) { 949 brelse(bp); 950 break; 951 } 952 offset += sizeof(struct direntry); 953 while (1) { 954 /* 955 * We are a bit agressive here in that we delete any Win95 956 * entries preceding this entry, not just the ones we "own". 957 * Since these presumably aren't valid anyway, 958 * there should be no harm. 959 */ 960 offset -= sizeof(struct direntry); 961 ep--->deName[0] = SLOT_DELETED; 962 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) 963 || !(offset & pmp->pm_crbomask) 964 || ep->deAttributes != ATTR_WIN95) 965 break; 966 } 967 if ((error = bwrite(bp)) != 0) 968 return error; 969 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95) 970 && !(offset & pmp->pm_crbomask) 971 && offset); 972 return 0; 973 } 974 975 /* 976 * Create a unique DOS name in dvp 977 */ 978 int 979 uniqdosname(dep, cnp, cp) 980 struct denode *dep; 981 struct componentname *cnp; 982 u_char *cp; 983 { 984 struct msdosfsmount *pmp = dep->de_pmp; 985 struct direntry *dentp; 986 int gen; 987 int blsize; 988 u_long cn; 989 daddr_t bn; 990 struct buf *bp; 991 int error; 992 993 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) 994 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 995 cnp->cn_namelen, 0, 996 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d, 997 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu) ? 998 0 : EINVAL); 999 1000 for (gen = 1;; gen++) { 1001 /* 1002 * Generate DOS name with generation number 1003 */ 1004 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 1005 cnp->cn_namelen, gen, 1006 pmp->pm_flags & MSDOSFSMNT_U2WTABLE, pmp->pm_u2d, 1007 pmp->pm_flags & MSDOSFSMNT_ULTABLE, pmp->pm_lu)) 1008 return gen == 1 ? EINVAL : EEXIST; 1009 1010 /* 1011 * Now look for a dir entry with this exact name 1012 */ 1013 for (cn = error = 0; !error; cn++) { 1014 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 1015 if (error == E2BIG) /* EOF reached and not found */ 1016 return 0; 1017 return error; 1018 } 1019 error = bread(pmp->pm_devvp, bn, blsize, &bp); 1020 if (error) { 1021 brelse(bp); 1022 return error; 1023 } 1024 for (dentp = (struct direntry *)bp->b_data; 1025 (char *)dentp < bp->b_data + blsize; 1026 dentp++) { 1027 if (dentp->deName[0] == SLOT_EMPTY) { 1028 /* 1029 * Last used entry and not found 1030 */ 1031 brelse(bp); 1032 return 0; 1033 } 1034 /* 1035 * Ignore volume labels and Win95 entries 1036 */ 1037 if (dentp->deAttributes & ATTR_VOLUME) 1038 continue; 1039 if (!bcmp(dentp->deName, cp, 11)) { 1040 error = EEXIST; 1041 break; 1042 } 1043 } 1044 brelse(bp); 1045 } 1046 } 1047 } 1048 1049 /* 1050 * Find any Win'95 long filename entry in directory dep 1051 */ 1052 int 1053 findwin95(dep) 1054 struct denode *dep; 1055 { 1056 struct msdosfsmount *pmp = dep->de_pmp; 1057 struct direntry *dentp; 1058 int blsize, win95; 1059 u_long cn; 1060 daddr_t bn; 1061 struct buf *bp; 1062 1063 win95 = 1; 1064 /* 1065 * Read through the directory looking for Win'95 entries 1066 * Note: Error currently handled just as EOF XXX 1067 */ 1068 for (cn = 0;; cn++) { 1069 if (pcbmap(dep, cn, &bn, 0, &blsize)) 1070 return (win95); 1071 if (bread(pmp->pm_devvp, bn, blsize, &bp)) { 1072 brelse(bp); 1073 return (win95); 1074 } 1075 for (dentp = (struct direntry *)bp->b_data; 1076 (char *)dentp < bp->b_data + blsize; 1077 dentp++) { 1078 if (dentp->deName[0] == SLOT_EMPTY) { 1079 /* 1080 * Last used entry and not found 1081 */ 1082 brelse(bp); 1083 return (win95); 1084 } 1085 if (dentp->deName[0] == SLOT_DELETED) { 1086 /* 1087 * Ignore deleted files 1088 * Note: might be an indication of Win'95 anyway XXX 1089 */ 1090 continue; 1091 } 1092 if (dentp->deAttributes == ATTR_WIN95) { 1093 brelse(bp); 1094 return 1; 1095 } 1096 win95 = 0; 1097 } 1098 brelse(bp); 1099 } 1100 } 1101