| 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 1.5 2003/08/07 21:17:41 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 &= ~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 & LOCKPARENT; |
| 129 | wantparent = flags & (LOCKPARENT | 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 == CREATE || nameiop == RENAME) && |
| 185 | (flags & 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 == CREATE || nameiop == RENAME) && |
| 339 | (flags & 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 |= SAVENAME; |
| 368 | if (!lockparent) { |
| 369 | VOP_UNLOCK(vdp, 0, td); |
| 370 | cnp->cn_flags |= PDIRUNLOCK; |
| 371 | } |
| 372 | return (EJUSTRETURN); |
| 373 | } |
| 374 | /* |
| 375 | * Insert name into cache (as non-existent) if appropriate. |
| 376 | */ |
| 377 | if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) |
| 378 | cache_enter(vdp, *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 == DELETE && (flags & 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, 0, td); |
| 461 | cnp->cn_flags |= 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 == RENAME && wantparent && |
| 473 | (flags & 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 |= SAVENAME; |
| 492 | if (!lockparent) { |
| 493 | VOP_UNLOCK(vdp, 0, td); |
| 494 | cnp->cn_flags |= 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 & ISDOTDOT) { |
| 520 | VOP_UNLOCK(pdp, 0, td); |
| 521 | cnp->cn_flags |= PDIRUNLOCK; |
| 522 | error = deget(pmp, cluster, blkoff, &tdp); |
| 523 | if (error) { |
| 524 | vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td); |
| 525 | cnp->cn_flags &= ~PDIRUNLOCK; |
| 526 | return (error); |
| 527 | } |
| 528 | if (lockparent && (flags & ISLASTCN)) { |
| 529 | error = vn_lock(pdp, LK_EXCLUSIVE, td); |
| 530 | if (error) { |
| 531 | vput(DETOV(tdp)); |
| 532 | return (error); |
| 533 | } |
| 534 | cnp->cn_flags &= ~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 & ISLASTCN)) { |
| 544 | VOP_UNLOCK(pdp, 0, td); |
| 545 | cnp->cn_flags |= PDIRUNLOCK; |
| 546 | } |
| 547 | *vpp = DETOV(tdp); |
| 548 | } |
| 549 | |
| 550 | /* |
| 551 | * Insert name into cache if appropriate. |
| 552 | */ |
| 553 | if (cnp->cn_flags & MAKEENTRY) |
| 554 | cache_enter(vdp, *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 | } |