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sys/fs/msdosfs/msdosfs_lookup.c
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1 /* $FreeBSD: releng/9.0/sys/fs/msdosfs/msdosfs_lookup.c 220014 2011-03-25 22:31:28Z 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 64 static int msdosfs_lookup_(struct vnode *vdp, struct vnode **vpp, 65 struct componentname *cnp, u_int64_t *inum); 66 static int msdosfs_deget_dotdot(struct vnode *vp, u_long cluster, int blkoff, 67 struct vnode **rvp); 68 69 int 70 msdosfs_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 */ 91 static int 92 msdosfs_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 #ifdef MSDOSFS_DEBUG 129 printf("msdosfs_lookup(): vdp %p, dp %p, Attr %02x\n", 130 vdp, dp, dp->de_Attributes); 131 #endif 132 133 restart: 134 if (vpp != NULL) 135 *vpp = NULL; 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++) */ 328 329 notfound: 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); 402 403 found: 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; 437 438 foundroot: 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 (EBUSY); 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 (EBUSY); 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 *vpp = NULL; 530 return (error); 531 } 532 /* 533 * Recheck that ".." still points to the inode we 534 * looked up before pdp lock was dropped. 535 */ 536 error = msdosfs_lookup_(pdp, NULL, cnp, &inode1); 537 if (error) { 538 vput(*vpp); 539 *vpp = NULL; 540 return (error); 541 } 542 if (VTODE(*vpp)->de_inode != inode1) { 543 vput(*vpp); 544 goto restart; 545 } 546 } else if (dp->de_StartCluster == scn && isadir) { 547 VREF(vdp); /* we want ourself, ie "." */ 548 *vpp = vdp; 549 } else { 550 if ((error = deget(pmp, cluster, blkoff, &tdp)) != 0) 551 return (error); 552 *vpp = DETOV(tdp); 553 } 554 555 /* 556 * Insert name into cache if appropriate. 557 */ 558 if (cnp->cn_flags & MAKEENTRY) 559 cache_enter(vdp, *vpp, cnp); 560 return (0); 561 } 562 563 static int 564 msdosfs_deget_dotdot(struct vnode *vp, u_long cluster, int blkoff, 565 struct vnode **rvp) 566 { 567 struct mount *mp; 568 struct msdosfsmount *pmp; 569 struct denode *rdp; 570 int ltype, error; 571 572 mp = vp->v_mount; 573 pmp = VFSTOMSDOSFS(mp); 574 ltype = VOP_ISLOCKED(vp); 575 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, 576 ("msdosfs_deget_dotdot: vp not locked")); 577 578 error = vfs_busy(mp, MBF_NOWAIT); 579 if (error != 0) { 580 vfs_ref(mp); 581 VOP_UNLOCK(vp, 0); 582 error = vfs_busy(mp, 0); 583 vn_lock(vp, ltype | LK_RETRY); 584 vfs_rel(mp); 585 if (error != 0) 586 return (ENOENT); 587 if (vp->v_iflag & VI_DOOMED) { 588 vfs_unbusy(mp); 589 return (ENOENT); 590 } 591 } 592 VOP_UNLOCK(vp, 0); 593 error = deget(pmp, cluster, blkoff, &rdp); 594 vfs_unbusy(mp); 595 if (error == 0) 596 *rvp = DETOV(rdp); 597 if (*rvp != vp) 598 vn_lock(vp, ltype | LK_RETRY); 599 if (vp->v_iflag & VI_DOOMED) { 600 if (error == 0) { 601 if (*rvp == vp) 602 vunref(*rvp); 603 else 604 vput(*rvp); 605 } 606 error = ENOENT; 607 } 608 return (error); 609 } 610 611 /* 612 * dep - directory entry to copy into the directory 613 * ddep - directory to add to 614 * depp - return the address of the denode for the created directory entry 615 * if depp != 0 616 * cnp - componentname needed for Win95 long filenames 617 */ 618 int 619 createde(dep, ddep, depp, cnp) 620 struct denode *dep; 621 struct denode *ddep; 622 struct denode **depp; 623 struct componentname *cnp; 624 { 625 int error; 626 u_long dirclust, diroffset; 627 struct direntry *ndep; 628 struct msdosfsmount *pmp = ddep->de_pmp; 629 struct buf *bp; 630 daddr_t bn; 631 int blsize; 632 633 #ifdef MSDOSFS_DEBUG 634 printf("createde(dep %p, ddep %p, depp %p, cnp %p)\n", 635 dep, ddep, depp, cnp); 636 #endif 637 638 /* 639 * If no space left in the directory then allocate another cluster 640 * and chain it onto the end of the file. There is one exception 641 * to this. That is, if the root directory has no more space it 642 * can NOT be expanded. extendfile() checks for and fails attempts 643 * to extend the root directory. We just return an error in that 644 * case. 645 */ 646 if (ddep->de_fndoffset >= ddep->de_FileSize) { 647 diroffset = ddep->de_fndoffset + sizeof(struct direntry) 648 - ddep->de_FileSize; 649 dirclust = de_clcount(pmp, diroffset); 650 error = extendfile(ddep, dirclust, 0, 0, DE_CLEAR); 651 if (error) { 652 (void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED, NULL); 653 return error; 654 } 655 656 /* 657 * Update the size of the directory 658 */ 659 ddep->de_FileSize += de_cn2off(pmp, dirclust); 660 } 661 662 /* 663 * We just read in the cluster with space. Copy the new directory 664 * entry in. Then write it to disk. NOTE: DOS directories 665 * do not get smaller as clusters are emptied. 666 */ 667 error = pcbmap(ddep, de_cluster(pmp, ddep->de_fndoffset), 668 &bn, &dirclust, &blsize); 669 if (error) 670 return error; 671 diroffset = ddep->de_fndoffset; 672 if (dirclust != MSDOSFSROOT) 673 diroffset &= pmp->pm_crbomask; 674 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) != 0) { 675 brelse(bp); 676 return error; 677 } 678 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 679 680 DE_EXTERNALIZE(ndep, dep); 681 682 /* 683 * Now write the Win95 long name 684 */ 685 if (ddep->de_fndcnt > 0) { 686 u_int8_t chksum = winChksum(ndep->deName); 687 const u_char *un = (const u_char *)cnp->cn_nameptr; 688 int unlen = cnp->cn_namelen; 689 int cnt = 1; 690 691 while (--ddep->de_fndcnt >= 0) { 692 if (!(ddep->de_fndoffset & pmp->pm_crbomask)) { 693 if (DETOV(ddep)->v_mount->mnt_flag & MNT_ASYNC) 694 bdwrite(bp); 695 else if ((error = bwrite(bp)) != 0) 696 return error; 697 698 ddep->de_fndoffset -= sizeof(struct direntry); 699 error = pcbmap(ddep, 700 de_cluster(pmp, 701 ddep->de_fndoffset), 702 &bn, 0, &blsize); 703 if (error) 704 return error; 705 706 error = bread(pmp->pm_devvp, bn, blsize, 707 NOCRED, &bp); 708 if (error) { 709 brelse(bp); 710 return error; 711 } 712 ndep = bptoep(pmp, bp, ddep->de_fndoffset); 713 } else { 714 ndep--; 715 ddep->de_fndoffset -= sizeof(struct direntry); 716 } 717 if (!unix2winfn(un, unlen, (struct winentry *)ndep, 718 cnt++, chksum, pmp)) 719 break; 720 } 721 } 722 723 if (DETOV(ddep)->v_mount->mnt_flag & MNT_ASYNC) 724 bdwrite(bp); 725 else if ((error = bwrite(bp)) != 0) 726 return error; 727 728 /* 729 * If they want us to return with the denode gotten. 730 */ 731 if (depp) { 732 if (dep->de_Attributes & ATTR_DIRECTORY) { 733 dirclust = dep->de_StartCluster; 734 if (FAT32(pmp) && dirclust == pmp->pm_rootdirblk) 735 dirclust = MSDOSFSROOT; 736 if (dirclust == MSDOSFSROOT) 737 diroffset = MSDOSFSROOT_OFS; 738 else 739 diroffset = 0; 740 } 741 return deget(pmp, dirclust, diroffset, depp); 742 } 743 744 return 0; 745 } 746 747 /* 748 * Be sure a directory is empty except for "." and "..". Return 1 if empty, 749 * return 0 if not empty or error. 750 */ 751 int 752 dosdirempty(dep) 753 struct denode *dep; 754 { 755 int blsize; 756 int error; 757 u_long cn; 758 daddr_t bn; 759 struct buf *bp; 760 struct msdosfsmount *pmp = dep->de_pmp; 761 struct direntry *dentp; 762 763 /* 764 * Since the filesize field in directory entries for a directory is 765 * zero, we just have to feel our way through the directory until 766 * we hit end of file. 767 */ 768 for (cn = 0;; cn++) { 769 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 770 if (error == E2BIG) 771 return (1); /* it's empty */ 772 return (0); 773 } 774 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 775 if (error) { 776 brelse(bp); 777 return (0); 778 } 779 for (dentp = (struct direntry *)bp->b_data; 780 (char *)dentp < bp->b_data + blsize; 781 dentp++) { 782 if (dentp->deName[0] != SLOT_DELETED && 783 (dentp->deAttributes & ATTR_VOLUME) == 0) { 784 /* 785 * In dos directories an entry whose name 786 * starts with SLOT_EMPTY (0) starts the 787 * beginning of the unused part of the 788 * directory, so we can just return that it 789 * is empty. 790 */ 791 if (dentp->deName[0] == SLOT_EMPTY) { 792 brelse(bp); 793 return (1); 794 } 795 /* 796 * Any names other than "." and ".." in a 797 * directory mean it is not empty. 798 */ 799 if (bcmp(dentp->deName, ". ", 11) && 800 bcmp(dentp->deName, ".. ", 11)) { 801 brelse(bp); 802 #ifdef MSDOSFS_DEBUG 803 printf("dosdirempty(): entry found %02x, %02x\n", 804 dentp->deName[0], dentp->deName[1]); 805 #endif 806 return (0); /* not empty */ 807 } 808 } 809 } 810 brelse(bp); 811 } 812 /* NOTREACHED */ 813 } 814 815 /* 816 * Check to see if the directory described by target is in some 817 * subdirectory of source. This prevents something like the following from 818 * succeeding and leaving a bunch or files and directories orphaned. mv 819 * /a/b/c /a/b/c/d/e/f Where c and f are directories. 820 * 821 * source - the inode for /a/b/c 822 * target - the inode for /a/b/c/d/e/f 823 * 824 * Returns 0 if target is NOT a subdirectory of source. 825 * Otherwise returns a non-zero error number. 826 * The target inode is always unlocked on return. 827 */ 828 int 829 doscheckpath(source, target) 830 struct denode *source; 831 struct denode *target; 832 { 833 daddr_t scn; 834 struct msdosfsmount *pmp; 835 struct direntry *ep; 836 struct denode *dep; 837 struct buf *bp = NULL; 838 int error = 0; 839 840 dep = target; 841 if ((target->de_Attributes & ATTR_DIRECTORY) == 0 || 842 (source->de_Attributes & ATTR_DIRECTORY) == 0) { 843 error = ENOTDIR; 844 goto out; 845 } 846 if (dep->de_StartCluster == source->de_StartCluster) { 847 error = EEXIST; 848 goto out; 849 } 850 if (dep->de_StartCluster == MSDOSFSROOT) 851 goto out; 852 pmp = dep->de_pmp; 853 #ifdef DIAGNOSTIC 854 if (pmp != source->de_pmp) 855 panic("doscheckpath: source and target on different filesystems"); 856 #endif 857 if (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk) 858 goto out; 859 860 for (;;) { 861 if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) { 862 error = ENOTDIR; 863 break; 864 } 865 scn = dep->de_StartCluster; 866 error = bread(pmp->pm_devvp, cntobn(pmp, scn), 867 pmp->pm_bpcluster, NOCRED, &bp); 868 if (error) 869 break; 870 871 ep = (struct direntry *) bp->b_data + 1; 872 if ((ep->deAttributes & ATTR_DIRECTORY) == 0 || 873 bcmp(ep->deName, ".. ", 11) != 0) { 874 error = ENOTDIR; 875 break; 876 } 877 scn = getushort(ep->deStartCluster); 878 if (FAT32(pmp)) 879 scn |= getushort(ep->deHighClust) << 16; 880 881 if (scn == source->de_StartCluster) { 882 error = EINVAL; 883 break; 884 } 885 if (scn == MSDOSFSROOT) 886 break; 887 if (FAT32(pmp) && scn == pmp->pm_rootdirblk) { 888 /* 889 * scn should be 0 in this case, 890 * but we silently ignore the error. 891 */ 892 break; 893 } 894 895 vput(DETOV(dep)); 896 brelse(bp); 897 bp = NULL; 898 /* NOTE: deget() clears dep on error */ 899 if ((error = deget(pmp, scn, 0, &dep)) != 0) 900 break; 901 } 902 out:; 903 if (bp) 904 brelse(bp); 905 if (error == ENOTDIR) 906 printf("doscheckpath(): .. not a directory?\n"); 907 if (dep != NULL) 908 vput(DETOV(dep)); 909 return (error); 910 } 911 912 /* 913 * Read in the disk block containing the directory entry (dirclu, dirofs) 914 * and return the address of the buf header, and the address of the 915 * directory entry within the block. 916 */ 917 int 918 readep(pmp, dirclust, diroffset, bpp, epp) 919 struct msdosfsmount *pmp; 920 u_long dirclust, diroffset; 921 struct buf **bpp; 922 struct direntry **epp; 923 { 924 int error; 925 daddr_t bn; 926 int blsize; 927 928 blsize = pmp->pm_bpcluster; 929 if (dirclust == MSDOSFSROOT 930 && de_blk(pmp, diroffset + blsize) > pmp->pm_rootdirsize) 931 blsize = de_bn2off(pmp, pmp->pm_rootdirsize) & pmp->pm_crbomask; 932 bn = detobn(pmp, dirclust, diroffset); 933 if ((error = bread(pmp->pm_devvp, bn, blsize, NOCRED, bpp)) != 0) { 934 brelse(*bpp); 935 *bpp = NULL; 936 return (error); 937 } 938 if (epp) 939 *epp = bptoep(pmp, *bpp, diroffset); 940 return (0); 941 } 942 943 /* 944 * Read in the disk block containing the directory entry dep came from and 945 * return the address of the buf header, and the address of the directory 946 * entry within the block. 947 */ 948 int 949 readde(dep, bpp, epp) 950 struct denode *dep; 951 struct buf **bpp; 952 struct direntry **epp; 953 { 954 955 return (readep(dep->de_pmp, dep->de_dirclust, dep->de_diroffset, 956 bpp, epp)); 957 } 958 959 /* 960 * Remove a directory entry. At this point the file represented by the 961 * directory entry to be removed is still full length until noone has it 962 * open. When the file no longer being used msdosfs_inactive() is called 963 * and will truncate the file to 0 length. When the vnode containing the 964 * denode is needed for some other purpose by VFS it will call 965 * msdosfs_reclaim() which will remove the denode from the denode cache. 966 */ 967 int 968 removede(pdep, dep) 969 struct denode *pdep; /* directory where the entry is removed */ 970 struct denode *dep; /* file to be removed */ 971 { 972 int error; 973 struct direntry *ep; 974 struct buf *bp; 975 daddr_t bn; 976 int blsize; 977 struct msdosfsmount *pmp = pdep->de_pmp; 978 u_long offset = pdep->de_fndoffset; 979 980 #ifdef MSDOSFS_DEBUG 981 printf("removede(): filename %s, dep %p, offset %08lx\n", 982 dep->de_Name, dep, offset); 983 #endif 984 985 dep->de_refcnt--; 986 offset += sizeof(struct direntry); 987 do { 988 offset -= sizeof(struct direntry); 989 error = pcbmap(pdep, de_cluster(pmp, offset), &bn, 0, &blsize); 990 if (error) 991 return error; 992 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 993 if (error) { 994 brelse(bp); 995 return error; 996 } 997 ep = bptoep(pmp, bp, offset); 998 /* 999 * Check whether, if we came here the second time, i.e. 1000 * when underflowing into the previous block, the last 1001 * entry in this block is a longfilename entry, too. 1002 */ 1003 if (ep->deAttributes != ATTR_WIN95 1004 && offset != pdep->de_fndoffset) { 1005 brelse(bp); 1006 break; 1007 } 1008 offset += sizeof(struct direntry); 1009 while (1) { 1010 /* 1011 * We are a bit agressive here in that we delete any Win95 1012 * entries preceding this entry, not just the ones we "own". 1013 * Since these presumably aren't valid anyway, 1014 * there should be no harm. 1015 */ 1016 offset -= sizeof(struct direntry); 1017 ep--->deName[0] = SLOT_DELETED; 1018 if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) 1019 || !(offset & pmp->pm_crbomask) 1020 || ep->deAttributes != ATTR_WIN95) 1021 break; 1022 } 1023 if (DETOV(pdep)->v_mount->mnt_flag & MNT_ASYNC) 1024 bdwrite(bp); 1025 else if ((error = bwrite(bp)) != 0) 1026 return error; 1027 } while (!(pmp->pm_flags & MSDOSFSMNT_NOWIN95) 1028 && !(offset & pmp->pm_crbomask) 1029 && offset); 1030 return 0; 1031 } 1032 1033 /* 1034 * Create a unique DOS name in dvp 1035 */ 1036 int 1037 uniqdosname(dep, cnp, cp) 1038 struct denode *dep; 1039 struct componentname *cnp; 1040 u_char *cp; 1041 { 1042 struct msdosfsmount *pmp = dep->de_pmp; 1043 struct direntry *dentp; 1044 int gen; 1045 int blsize; 1046 u_long cn; 1047 daddr_t bn; 1048 struct buf *bp; 1049 int error; 1050 1051 if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME) 1052 return (unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 1053 cnp->cn_namelen, 0, pmp) ? 0 : EINVAL); 1054 1055 for (gen = 1;; gen++) { 1056 /* 1057 * Generate DOS name with generation number 1058 */ 1059 if (!unix2dosfn((const u_char *)cnp->cn_nameptr, cp, 1060 cnp->cn_namelen, gen, pmp)) 1061 return gen == 1 ? EINVAL : EEXIST; 1062 1063 /* 1064 * Now look for a dir entry with this exact name 1065 */ 1066 for (cn = error = 0; !error; cn++) { 1067 if ((error = pcbmap(dep, cn, &bn, 0, &blsize)) != 0) { 1068 if (error == E2BIG) /* EOF reached and not found */ 1069 return 0; 1070 return error; 1071 } 1072 error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp); 1073 if (error) { 1074 brelse(bp); 1075 return error; 1076 } 1077 for (dentp = (struct direntry *)bp->b_data; 1078 (char *)dentp < bp->b_data + blsize; 1079 dentp++) { 1080 if (dentp->deName[0] == SLOT_EMPTY) { 1081 /* 1082 * Last used entry and not found 1083 */ 1084 brelse(bp); 1085 return 0; 1086 } 1087 /* 1088 * Ignore volume labels and Win95 entries 1089 */ 1090 if (dentp->deAttributes & ATTR_VOLUME) 1091 continue; 1092 if (!bcmp(dentp->deName, cp, 11)) { 1093 error = EEXIST; 1094 break; 1095 } 1096 } 1097 brelse(bp); 1098 } 1099 } 1100 } 1101 1102 /* 1103 * Find any Win'95 long filename entry in directory dep 1104 */ 1105 int 1106 findwin95(dep) 1107 struct denode *dep; 1108 { 1109 struct msdosfsmount *pmp = dep->de_pmp; 1110 struct direntry *dentp; 1111 int blsize, win95; 1112 u_long cn; 1113 daddr_t bn; 1114 struct buf *bp; 1115 1116 win95 = 1; 1117 /* 1118 * Read through the directory looking for Win'95 entries 1119 * Note: Error currently handled just as EOF XXX 1120 */ 1121 for (cn = 0;; cn++) { 1122 if (pcbmap(dep, cn, &bn, 0, &blsize)) 1123 return (win95); 1124 if (bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp)) { 1125 brelse(bp); 1126 return (win95); 1127 } 1128 for (dentp = (struct direntry *)bp->b_data; 1129 (char *)dentp < bp->b_data + blsize; 1130 dentp++) { 1131 if (dentp->deName[0] == SLOT_EMPTY) { 1132 /* 1133 * Last used entry and not found 1134 */ 1135 brelse(bp); 1136 return (win95); 1137 } 1138 if (dentp->deName[0] == SLOT_DELETED) { 1139 /* 1140 * Ignore deleted files 1141 * Note: might be an indication of Win'95 anyway XXX 1142 */ 1143 continue; 1144 } 1145 if (dentp->deAttributes == ATTR_WIN95) { 1146 brelse(bp); 1147 return 1; 1148 } 1149 win95 = 0; 1150 } 1151 brelse(bp); 1152 } 1153 }
Cache object: dcc25c8a840e0c923c55b4f8efc90bfd
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