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sys/fs/ext2fs/ext2_lookup.c
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1 /*- 2 * modified for Lites 1.1 3 * 4 * Aug 1995, Godmar Back (gback@cs.utah.edu) 5 * University of Utah, Department of Computer Science 6 */ 7 /*- 8 * SPDX-License-Identifier: BSD-3-Clause 9 * 10 * Copyright (c) 1989, 1993 11 * The Regents of the University of California. All rights reserved. 12 * (c) UNIX System Laboratories, Inc. 13 * All or some portions of this file are derived from material licensed 14 * to the University of California by American Telephone and Telegraph 15 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 16 * the permission of UNIX System Laboratories, Inc. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 3. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)ufs_lookup.c 8.6 (Berkeley) 4/1/94 43 * $FreeBSD: releng/12.0/sys/fs/ext2fs/ext2_lookup.c 341085 2018-11-27 17:58:25Z markj $ 44 */ 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/namei.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/endian.h> 52 #include <sys/mount.h> 53 #include <sys/vnode.h> 54 #include <sys/malloc.h> 55 #include <sys/dirent.h> 56 #include <sys/sysctl.h> 57 58 #include <ufs/ufs/dir.h> 59 60 #include <fs/ext2fs/fs.h> 61 #include <fs/ext2fs/inode.h> 62 #include <fs/ext2fs/ext2_mount.h> 63 #include <fs/ext2fs/ext2fs.h> 64 #include <fs/ext2fs/ext2_dinode.h> 65 #include <fs/ext2fs/ext2_dir.h> 66 #include <fs/ext2fs/ext2_extern.h> 67 #include <fs/ext2fs/fs.h> 68 69 #ifdef INVARIANTS 70 static int dirchk = 1; 71 #else 72 static int dirchk = 0; 73 #endif 74 75 static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD, 0, "EXT2FS filesystem"); 76 SYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, ""); 77 78 /* 79 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) 80 while it is the native blocksize in ext2fs - thus, a #define 81 is no longer appropriate 82 */ 83 #undef DIRBLKSIZ 84 85 static u_char ext2_ft_to_dt[] = { 86 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ 87 DT_REG, /* EXT2_FT_REG_FILE */ 88 DT_DIR, /* EXT2_FT_DIR */ 89 DT_CHR, /* EXT2_FT_CHRDEV */ 90 DT_BLK, /* EXT2_FT_BLKDEV */ 91 DT_FIFO, /* EXT2_FT_FIFO */ 92 DT_SOCK, /* EXT2_FT_SOCK */ 93 DT_LNK, /* EXT2_FT_SYMLINK */ 94 }; 95 #define FTTODT(ft) \ 96 ((ft) < nitems(ext2_ft_to_dt) ? ext2_ft_to_dt[(ft)] : DT_UNKNOWN) 97 98 static u_char dt_to_ext2_ft[] = { 99 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ 100 EXT2_FT_FIFO, /* DT_FIFO */ 101 EXT2_FT_CHRDEV, /* DT_CHR */ 102 EXT2_FT_UNKNOWN, /* unused */ 103 EXT2_FT_DIR, /* DT_DIR */ 104 EXT2_FT_UNKNOWN, /* unused */ 105 EXT2_FT_BLKDEV, /* DT_BLK */ 106 EXT2_FT_UNKNOWN, /* unused */ 107 EXT2_FT_REG_FILE, /* DT_REG */ 108 EXT2_FT_UNKNOWN, /* unused */ 109 EXT2_FT_SYMLINK, /* DT_LNK */ 110 EXT2_FT_UNKNOWN, /* unused */ 111 EXT2_FT_SOCK, /* DT_SOCK */ 112 EXT2_FT_UNKNOWN, /* unused */ 113 EXT2_FT_UNKNOWN, /* DT_WHT */ 114 }; 115 #define DTTOFT(dt) \ 116 ((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN) 117 118 static int ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2 *de, 119 int entryoffsetinblock); 120 static int ext2_is_dot_entry(struct componentname *cnp); 121 static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, 122 struct componentname *cnp, ino_t *dd_ino); 123 124 static int 125 ext2_is_dot_entry(struct componentname *cnp) 126 { 127 if (cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' && 128 (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0')) 129 return (1); 130 return (0); 131 } 132 133 /* 134 * Vnode op for reading directories. 135 */ 136 int 137 ext2_readdir(struct vop_readdir_args *ap) 138 { 139 struct vnode *vp = ap->a_vp; 140 struct uio *uio = ap->a_uio; 141 struct buf *bp; 142 struct inode *ip; 143 struct ext2fs_direct_2 *dp, *edp; 144 u_long *cookies; 145 struct dirent dstdp; 146 off_t offset, startoffset; 147 size_t readcnt, skipcnt; 148 ssize_t startresid; 149 u_int ncookies; 150 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->e2fs_bsize; 151 int error; 152 153 if (uio->uio_offset < 0) 154 return (EINVAL); 155 ip = VTOI(vp); 156 if (ap->a_ncookies != NULL) { 157 if (uio->uio_resid < 0) 158 ncookies = 0; 159 else 160 ncookies = uio->uio_resid; 161 if (uio->uio_offset >= ip->i_size) 162 ncookies = 0; 163 else if (ip->i_size - uio->uio_offset < ncookies) 164 ncookies = ip->i_size - uio->uio_offset; 165 ncookies = ncookies / (offsetof(struct ext2fs_direct_2, 166 e2d_namlen) + 4) + 1; 167 cookies = malloc(ncookies * sizeof(*cookies), M_TEMP, M_WAITOK); 168 *ap->a_ncookies = ncookies; 169 *ap->a_cookies = cookies; 170 } else { 171 ncookies = 0; 172 cookies = NULL; 173 } 174 offset = startoffset = uio->uio_offset; 175 startresid = uio->uio_resid; 176 error = 0; 177 while (error == 0 && uio->uio_resid > 0 && 178 uio->uio_offset < ip->i_size) { 179 error = ext2_blkatoff(vp, uio->uio_offset, NULL, &bp); 180 if (error) 181 break; 182 if (bp->b_offset + bp->b_bcount > ip->i_size) 183 readcnt = ip->i_size - bp->b_offset; 184 else 185 readcnt = bp->b_bcount; 186 skipcnt = (size_t)(uio->uio_offset - bp->b_offset) & 187 ~(size_t)(DIRBLKSIZ - 1); 188 offset = bp->b_offset + skipcnt; 189 dp = (struct ext2fs_direct_2 *)&bp->b_data[skipcnt]; 190 edp = (struct ext2fs_direct_2 *)&bp->b_data[readcnt]; 191 while (error == 0 && uio->uio_resid > 0 && dp < edp) { 192 if (dp->e2d_reclen <= offsetof(struct ext2fs_direct_2, 193 e2d_namlen) || (caddr_t)dp + dp->e2d_reclen > 194 (caddr_t)edp) { 195 error = EIO; 196 break; 197 } 198 /*- 199 * "New" ext2fs directory entries differ in 3 ways 200 * from ufs on-disk ones: 201 * - the name is not necessarily NUL-terminated. 202 * - the file type field always exists and always 203 * follows the name length field. 204 * - the file type is encoded in a different way. 205 * 206 * "Old" ext2fs directory entries need no special 207 * conversions, since they are binary compatible 208 * with "new" entries having a file type of 0 (i.e., 209 * EXT2_FT_UNKNOWN). Splitting the old name length 210 * field didn't make a mess like it did in ufs, 211 * because ext2fs uses a machine-independent disk 212 * layout. 213 */ 214 dstdp.d_namlen = dp->e2d_namlen; 215 dstdp.d_type = FTTODT(dp->e2d_type); 216 if (offsetof(struct ext2fs_direct_2, e2d_namlen) + 217 dstdp.d_namlen > dp->e2d_reclen) { 218 error = EIO; 219 break; 220 } 221 if (offset < startoffset || dp->e2d_ino == 0) 222 goto nextentry; 223 dstdp.d_fileno = dp->e2d_ino; 224 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); 225 bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen); 226 dirent_terminate(&dstdp); 227 if (dstdp.d_reclen > uio->uio_resid) { 228 if (uio->uio_resid == startresid) 229 error = EINVAL; 230 else 231 error = EJUSTRETURN; 232 break; 233 } 234 /* Advance dp. */ 235 error = uiomove((caddr_t)&dstdp, dstdp.d_reclen, uio); 236 if (error) 237 break; 238 if (cookies != NULL) { 239 KASSERT(ncookies > 0, 240 ("ext2_readdir: cookies buffer too small")); 241 *cookies = offset + dp->e2d_reclen; 242 cookies++; 243 ncookies--; 244 } 245 nextentry: 246 offset += dp->e2d_reclen; 247 dp = (struct ext2fs_direct_2 *)((caddr_t)dp + 248 dp->e2d_reclen); 249 } 250 bqrelse(bp); 251 uio->uio_offset = offset; 252 } 253 /* We need to correct uio_offset. */ 254 uio->uio_offset = offset; 255 if (error == EJUSTRETURN) 256 error = 0; 257 if (ap->a_ncookies != NULL) { 258 if (error == 0) { 259 ap->a_ncookies -= ncookies; 260 } else { 261 free(*ap->a_cookies, M_TEMP); 262 *ap->a_ncookies = 0; 263 *ap->a_cookies = NULL; 264 } 265 } 266 if (error == 0 && ap->a_eofflag) 267 *ap->a_eofflag = ip->i_size <= uio->uio_offset; 268 return (error); 269 } 270 271 /* 272 * Convert a component of a pathname into a pointer to a locked inode. 273 * This is a very central and rather complicated routine. 274 * If the file system is not maintained in a strict tree hierarchy, 275 * this can result in a deadlock situation (see comments in code below). 276 * 277 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending 278 * on whether the name is to be looked up, created, renamed, or deleted. 279 * When CREATE, RENAME, or DELETE is specified, information usable in 280 * creating, renaming, or deleting a directory entry may be calculated. 281 * If flag has LOCKPARENT or'ed into it and the target of the pathname 282 * exists, lookup returns both the target and its parent directory locked. 283 * When creating or renaming and LOCKPARENT is specified, the target may 284 * not be ".". When deleting and LOCKPARENT is specified, the target may 285 * be "."., but the caller must check to ensure it does an vrele and vput 286 * instead of two vputs. 287 * 288 * Overall outline of ext2_lookup: 289 * 290 * search for name in directory, to found or notfound 291 * notfound: 292 * if creating, return locked directory, leaving info on available slots 293 * else return error 294 * found: 295 * if at end of path and deleting, return information to allow delete 296 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target 297 * inode and return info to allow rewrite 298 * if not at end, add name to cache; if at end and neither creating 299 * nor deleting, add name to cache 300 */ 301 int 302 ext2_lookup(struct vop_cachedlookup_args *ap) 303 { 304 305 return (ext2_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL)); 306 } 307 308 static int 309 ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp, 310 ino_t *dd_ino) 311 { 312 struct inode *dp; /* inode for directory being searched */ 313 struct buf *bp; /* a buffer of directory entries */ 314 struct ext2fs_direct_2 *ep; /* the current directory entry */ 315 int entryoffsetinblock; /* offset of ep in bp's buffer */ 316 struct ext2fs_searchslot ss; 317 doff_t i_diroff; /* cached i_diroff value */ 318 doff_t i_offset; /* cached i_offset value */ 319 int numdirpasses; /* strategy for directory search */ 320 doff_t endsearch; /* offset to end directory search */ 321 doff_t prevoff; /* prev entry dp->i_offset */ 322 struct vnode *pdp; /* saved dp during symlink work */ 323 struct vnode *tdp; /* returned by VFS_VGET */ 324 doff_t enduseful; /* pointer past last used dir slot */ 325 u_long bmask; /* block offset mask */ 326 int error; 327 struct ucred *cred = cnp->cn_cred; 328 int flags = cnp->cn_flags; 329 int nameiop = cnp->cn_nameiop; 330 ino_t ino, ino1; 331 int ltype; 332 int entry_found = 0; 333 334 int DIRBLKSIZ = VTOI(vdp)->i_e2fs->e2fs_bsize; 335 336 if (vpp != NULL) 337 *vpp = NULL; 338 339 dp = VTOI(vdp); 340 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; 341 restart: 342 bp = NULL; 343 ss.slotoffset = -1; 344 345 /* 346 * We now have a segment name to search for, and a directory to search. 347 * 348 * Suppress search for slots unless creating 349 * file and at end of pathname, in which case 350 * we watch for a place to put the new file in 351 * case it doesn't already exist. 352 */ 353 i_diroff = dp->i_diroff; 354 ss.slotstatus = FOUND; 355 ss.slotfreespace = ss.slotsize = ss.slotneeded = 0; 356 if ((nameiop == CREATE || nameiop == RENAME) && 357 (flags & ISLASTCN)) { 358 ss.slotstatus = NONE; 359 ss.slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); 360 /* 361 * was ss.slotneeded = (sizeof(struct direct) - MAXNAMLEN + 362 * cnp->cn_namelen + 3) &~ 3; 363 */ 364 } 365 /* 366 * Try to lookup dir entry using htree directory index. 367 * 368 * If we got an error or we want to find '.' or '..' entry, 369 * we will fall back to linear search. 370 */ 371 if (!ext2_is_dot_entry(cnp) && ext2_htree_has_idx(dp)) { 372 numdirpasses = 1; 373 entryoffsetinblock = 0; 374 switch (ext2_htree_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen, 375 &bp, &entryoffsetinblock, &i_offset, &prevoff, 376 &enduseful, &ss)) { 377 case 0: 378 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 379 (i_offset & bmask)); 380 goto foundentry; 381 case ENOENT: 382 i_offset = roundup2(dp->i_size, DIRBLKSIZ); 383 goto notfound; 384 default: 385 /* 386 * Something failed; just fallback to do a linear 387 * search. 388 */ 389 break; 390 } 391 } 392 393 /* 394 * If there is cached information on a previous search of 395 * this directory, pick up where we last left off. 396 * We cache only lookups as these are the most common 397 * and have the greatest payoff. Caching CREATE has little 398 * benefit as it usually must search the entire directory 399 * to determine that the entry does not exist. Caching the 400 * location of the last DELETE or RENAME has not reduced 401 * profiling time and hence has been removed in the interest 402 * of simplicity. 403 */ 404 if (nameiop != LOOKUP || i_diroff == 0 || 405 i_diroff > dp->i_size) { 406 entryoffsetinblock = 0; 407 i_offset = 0; 408 numdirpasses = 1; 409 } else { 410 i_offset = i_diroff; 411 if ((entryoffsetinblock = i_offset & bmask) && 412 (error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, 413 &bp))) 414 return (error); 415 numdirpasses = 2; 416 nchstats.ncs_2passes++; 417 } 418 prevoff = i_offset; 419 endsearch = roundup2(dp->i_size, DIRBLKSIZ); 420 enduseful = 0; 421 422 searchloop: 423 while (i_offset < endsearch) { 424 /* 425 * If necessary, get the next directory block. 426 */ 427 if (bp != NULL) 428 brelse(bp); 429 error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, &bp); 430 if (error != 0) 431 return (error); 432 433 entryoffsetinblock = 0; 434 if (ss.slotstatus == NONE) { 435 ss.slotoffset = -1; 436 ss.slotfreespace = 0; 437 } 438 439 error = ext2_search_dirblock(dp, bp->b_data, &entry_found, 440 cnp->cn_nameptr, cnp->cn_namelen, 441 &entryoffsetinblock, &i_offset, &prevoff, 442 &enduseful, &ss); 443 if (error != 0) { 444 brelse(bp); 445 return (error); 446 } 447 if (entry_found) { 448 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 449 (entryoffsetinblock & bmask)); 450 foundentry: 451 ino = ep->e2d_ino; 452 goto found; 453 } 454 } 455 notfound: 456 /* 457 * If we started in the middle of the directory and failed 458 * to find our target, we must check the beginning as well. 459 */ 460 if (numdirpasses == 2) { 461 numdirpasses--; 462 i_offset = 0; 463 endsearch = i_diroff; 464 goto searchloop; 465 } 466 if (bp != NULL) 467 brelse(bp); 468 /* 469 * If creating, and at end of pathname and current 470 * directory has not been removed, then can consider 471 * allowing file to be created. 472 */ 473 if ((nameiop == CREATE || nameiop == RENAME) && 474 (flags & ISLASTCN) && dp->i_nlink != 0) { 475 /* 476 * Access for write is interpreted as allowing 477 * creation of files in the directory. 478 */ 479 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 480 return (error); 481 /* 482 * Return an indication of where the new directory 483 * entry should be put. If we didn't find a slot, 484 * then set dp->i_count to 0 indicating 485 * that the new slot belongs at the end of the 486 * directory. If we found a slot, then the new entry 487 * can be put in the range from dp->i_offset to 488 * dp->i_offset + dp->i_count. 489 */ 490 if (ss.slotstatus == NONE) { 491 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); 492 dp->i_count = 0; 493 enduseful = dp->i_offset; 494 } else { 495 dp->i_offset = ss.slotoffset; 496 dp->i_count = ss.slotsize; 497 if (enduseful < ss.slotoffset + ss.slotsize) 498 enduseful = ss.slotoffset + ss.slotsize; 499 } 500 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ); 501 /* 502 * We return with the directory locked, so that 503 * the parameters we set up above will still be 504 * valid if we actually decide to do a direnter(). 505 * We return ni_vp == NULL to indicate that the entry 506 * does not currently exist; we leave a pointer to 507 * the (locked) directory inode in ndp->ni_dvp. 508 * The pathname buffer is saved so that the name 509 * can be obtained later. 510 * 511 * NB - if the directory is unlocked, then this 512 * information cannot be used. 513 */ 514 cnp->cn_flags |= SAVENAME; 515 return (EJUSTRETURN); 516 } 517 /* 518 * Insert name into cache (as non-existent) if appropriate. 519 */ 520 if ((cnp->cn_flags & MAKEENTRY) != 0) 521 cache_enter(vdp, NULL, cnp); 522 return (ENOENT); 523 524 found: 525 if (dd_ino != NULL) 526 *dd_ino = ino; 527 if (numdirpasses == 2) 528 nchstats.ncs_pass2++; 529 /* 530 * Check that directory length properly reflects presence 531 * of this entry. 532 */ 533 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen) 534 > dp->i_size) { 535 ext2_dirbad(dp, i_offset, "i_size too small"); 536 dp->i_size = entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen); 537 dp->i_flag |= IN_CHANGE | IN_UPDATE; 538 } 539 brelse(bp); 540 541 /* 542 * Found component in pathname. 543 * If the final component of path name, save information 544 * in the cache as to where the entry was found. 545 */ 546 if ((flags & ISLASTCN) && nameiop == LOOKUP) 547 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ); 548 /* 549 * If deleting, and at end of pathname, return 550 * parameters which can be used to remove file. 551 */ 552 if (nameiop == DELETE && (flags & ISLASTCN)) { 553 if (flags & LOCKPARENT) 554 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__); 555 /* 556 * Write access to directory required to delete files. 557 */ 558 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 559 return (error); 560 /* 561 * Return pointer to current entry in dp->i_offset, 562 * and distance past previous entry (if there 563 * is a previous entry in this block) in dp->i_count. 564 * Save directory inode pointer in ndp->ni_dvp for dirremove(). 565 * 566 * Technically we shouldn't be setting these in the 567 * WANTPARENT case (first lookup in rename()), but any 568 * lookups that will result in directory changes will 569 * overwrite these. 570 */ 571 dp->i_offset = i_offset; 572 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) 573 dp->i_count = 0; 574 else 575 dp->i_count = dp->i_offset - prevoff; 576 if (dd_ino != NULL) 577 return (0); 578 if (dp->i_number == ino) { 579 VREF(vdp); 580 *vpp = vdp; 581 return (0); 582 } 583 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, 584 &tdp)) != 0) 585 return (error); 586 /* 587 * If directory is "sticky", then user must own 588 * the directory, or the file in it, else she 589 * may not delete it (unless she's root). This 590 * implements append-only directories. 591 */ 592 if ((dp->i_mode & ISVTX) && 593 cred->cr_uid != 0 && 594 cred->cr_uid != dp->i_uid && 595 VTOI(tdp)->i_uid != cred->cr_uid) { 596 vput(tdp); 597 return (EPERM); 598 } 599 *vpp = tdp; 600 return (0); 601 } 602 603 /* 604 * If rewriting (RENAME), return the inode and the 605 * information required to rewrite the present directory 606 * Must get inode of directory entry to verify it's a 607 * regular file, or empty directory. 608 */ 609 if (nameiop == RENAME && (flags & ISLASTCN)) { 610 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 611 return (error); 612 /* 613 * Careful about locking second inode. 614 * This can only occur if the target is ".". 615 */ 616 dp->i_offset = i_offset; 617 if (dp->i_number == ino) 618 return (EISDIR); 619 if (dd_ino != NULL) 620 return (0); 621 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, 622 &tdp)) != 0) 623 return (error); 624 *vpp = tdp; 625 cnp->cn_flags |= SAVENAME; 626 return (0); 627 } 628 if (dd_ino != NULL) 629 return (0); 630 631 /* 632 * Step through the translation in the name. We do not `vput' the 633 * directory because we may need it again if a symbolic link 634 * is relative to the current directory. Instead we save it 635 * unlocked as "pdp". We must get the target inode before unlocking 636 * the directory to insure that the inode will not be removed 637 * before we get it. We prevent deadlock by always fetching 638 * inodes from the root, moving down the directory tree. Thus 639 * when following backward pointers ".." we must unlock the 640 * parent directory before getting the requested directory. 641 * There is a potential race condition here if both the current 642 * and parent directories are removed before the VFS_VGET for the 643 * inode associated with ".." returns. We hope that this occurs 644 * infrequently since we cannot avoid this race condition without 645 * implementing a sophisticated deadlock detection algorithm. 646 * Note also that this simple deadlock detection scheme will not 647 * work if the file system has any hard links other than ".." 648 * that point backwards in the directory structure. 649 */ 650 pdp = vdp; 651 if (flags & ISDOTDOT) { 652 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp); 653 if (pdp->v_iflag & VI_DOOMED) { 654 if (error == 0) 655 vput(tdp); 656 error = ENOENT; 657 } 658 if (error) 659 return (error); 660 /* 661 * Recheck that ".." entry in the vdp directory points 662 * to the inode we looked up before vdp lock was 663 * dropped. 664 */ 665 error = ext2_lookup_ino(pdp, NULL, cnp, &ino1); 666 if (error) { 667 vput(tdp); 668 return (error); 669 } 670 if (ino1 != ino) { 671 vput(tdp); 672 goto restart; 673 } 674 *vpp = tdp; 675 } else if (dp->i_number == ino) { 676 VREF(vdp); /* we want ourself, ie "." */ 677 /* 678 * When we lookup "." we still can be asked to lock it 679 * differently. 680 */ 681 ltype = cnp->cn_lkflags & LK_TYPE_MASK; 682 if (ltype != VOP_ISLOCKED(vdp)) { 683 if (ltype == LK_EXCLUSIVE) 684 vn_lock(vdp, LK_UPGRADE | LK_RETRY); 685 else /* if (ltype == LK_SHARED) */ 686 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY); 687 } 688 *vpp = vdp; 689 } else { 690 if ((error = VFS_VGET(vdp->v_mount, ino, cnp->cn_lkflags, 691 &tdp)) != 0) 692 return (error); 693 *vpp = tdp; 694 } 695 696 /* 697 * Insert name into cache if appropriate. 698 */ 699 if (cnp->cn_flags & MAKEENTRY) 700 cache_enter(vdp, *vpp, cnp); 701 return (0); 702 } 703 704 int 705 ext2_search_dirblock(struct inode *ip, void *data, int *foundp, 706 const char *name, int namelen, int *entryoffsetinblockp, 707 doff_t *offp, doff_t *prevoffp, doff_t *endusefulp, 708 struct ext2fs_searchslot *ssp) 709 { 710 struct vnode *vdp; 711 struct ext2fs_direct_2 *ep, *top; 712 uint32_t bsize = ip->i_e2fs->e2fs_bsize; 713 int offset = *entryoffsetinblockp; 714 int namlen; 715 716 vdp = ITOV(ip); 717 718 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 719 top = (struct ext2fs_direct_2 *)((char *)data + bsize); 720 while (ep < top) { 721 /* 722 * Full validation checks are slow, so we only check 723 * enough to insure forward progress through the 724 * directory. Complete checks can be run by setting 725 * "vfs.e2fs.dirchk" to be true. 726 */ 727 if (ep->e2d_reclen == 0 || 728 (dirchk && ext2_dirbadentry(vdp, ep, offset))) { 729 int i; 730 731 ext2_dirbad(ip, *offp, "mangled entry"); 732 i = bsize - (offset & (bsize - 1)); 733 *offp += i; 734 offset += i; 735 continue; 736 } 737 738 /* 739 * If an appropriate sized slot has not yet been found, 740 * check to see if one is available. Also accumulate space 741 * in the current block so that we can determine if 742 * compaction is viable. 743 */ 744 if (ssp->slotstatus != FOUND) { 745 int size = ep->e2d_reclen; 746 747 if (ep->e2d_ino != 0) 748 size -= EXT2_DIR_REC_LEN(ep->e2d_namlen); 749 else if (ext2_is_dirent_tail(ip, ep)) 750 size -= sizeof(struct ext2fs_direct_tail); 751 if (size > 0) { 752 if (size >= ssp->slotneeded) { 753 ssp->slotstatus = FOUND; 754 ssp->slotoffset = *offp; 755 ssp->slotsize = ep->e2d_reclen; 756 } else if (ssp->slotstatus == NONE) { 757 ssp->slotfreespace += size; 758 if (ssp->slotoffset == -1) 759 ssp->slotoffset = *offp; 760 if (ssp->slotfreespace >= ssp->slotneeded) { 761 ssp->slotstatus = COMPACT; 762 ssp->slotsize = *offp + 763 ep->e2d_reclen - 764 ssp->slotoffset; 765 } 766 } 767 } 768 } 769 /* 770 * Check for a name match. 771 */ 772 if (ep->e2d_ino) { 773 namlen = ep->e2d_namlen; 774 if (namlen == namelen && 775 !bcmp(name, ep->e2d_name, (unsigned)namlen)) { 776 /* 777 * Save directory entry's inode number and 778 * reclen in ndp->ni_ufs area, and release 779 * directory buffer. 780 */ 781 *foundp = 1; 782 return (0); 783 } 784 } 785 *prevoffp = *offp; 786 *offp += ep->e2d_reclen; 787 offset += ep->e2d_reclen; 788 *entryoffsetinblockp = offset; 789 if (ep->e2d_ino) 790 *endusefulp = *offp; 791 /* 792 * Get pointer to the next entry. 793 */ 794 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 795 } 796 797 return (0); 798 } 799 800 void 801 ext2_dirbad(struct inode *ip, doff_t offset, char *how) 802 { 803 struct mount *mp; 804 805 mp = ITOV(ip)->v_mount; 806 if ((mp->mnt_flag & MNT_RDONLY) == 0) 807 panic("ext2_dirbad: %s: bad dir ino %ju at offset %ld: %s\n", 808 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, 809 (long)offset, how); 810 else 811 (void)printf("%s: bad dir ino %ju at offset %ld: %s\n", 812 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, 813 (long)offset, how); 814 815 } 816 817 /* 818 * Do consistency checking on a directory entry: 819 * record length must be multiple of 4 820 * entry must fit in rest of its DIRBLKSIZ block 821 * record must be large enough to contain entry 822 * name is not longer than MAXNAMLEN 823 * name must be as long as advertised, and null terminated 824 */ 825 /* 826 * changed so that it confirms to ext2_check_dir_entry 827 */ 828 static int 829 ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2 *de, 830 int entryoffsetinblock) 831 { 832 int DIRBLKSIZ = VTOI(dp)->i_e2fs->e2fs_bsize; 833 834 char *error_msg = NULL; 835 836 if (de->e2d_reclen < EXT2_DIR_REC_LEN(1)) 837 error_msg = "rec_len is smaller than minimal"; 838 else if (de->e2d_reclen % 4 != 0) 839 error_msg = "rec_len % 4 != 0"; 840 else if (de->e2d_reclen < EXT2_DIR_REC_LEN(de->e2d_namlen)) 841 error_msg = "reclen is too small for name_len"; 842 else if (entryoffsetinblock + de->e2d_reclen > DIRBLKSIZ) 843 error_msg = "directory entry across blocks"; 844 /* else LATER 845 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count) 846 error_msg = "inode out of bounds"; 847 */ 848 849 if (error_msg != NULL) { 850 printf("bad directory entry: %s\n", error_msg); 851 printf("offset=%d, inode=%lu, rec_len=%u, name_len=%u\n", 852 entryoffsetinblock, (unsigned long)de->e2d_ino, 853 de->e2d_reclen, de->e2d_namlen); 854 } 855 return error_msg == NULL ? 0 : 1; 856 } 857 858 /* 859 * Insert an entry into the fresh directory block. 860 * Initialize entry tail if the metadata_csum feature is turned on. 861 */ 862 static int 863 ext2_add_first_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry, 864 struct componentname *cnp) 865 { 866 struct inode *dp; 867 struct iovec aiov; 868 struct uio auio; 869 char* buf = NULL; 870 int dirblksize, error; 871 872 dp = VTOI(dvp); 873 dirblksize = dp->i_e2fs->e2fs_bsize; 874 875 if (dp->i_offset & (dirblksize - 1)) 876 panic("ext2_add_first_entry: bad directory offset"); 877 878 if (EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs, 879 EXT2F_ROCOMPAT_METADATA_CKSUM)) { 880 entry->e2d_reclen = dirblksize - sizeof(struct ext2fs_direct_tail); 881 buf = malloc(dirblksize, M_TEMP, M_WAITOK); 882 if (!buf) { 883 error = ENOMEM; 884 goto out; 885 } 886 memcpy(buf, entry, EXT2_DIR_REC_LEN(entry->e2d_namlen)); 887 ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, dirblksize)); 888 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)buf); 889 890 auio.uio_offset = dp->i_offset; 891 auio.uio_resid = dirblksize; 892 aiov.iov_len = auio.uio_resid; 893 aiov.iov_base = (caddr_t)buf; 894 } else { 895 entry->e2d_reclen = dirblksize; 896 auio.uio_offset = dp->i_offset; 897 auio.uio_resid = EXT2_DIR_REC_LEN(entry->e2d_namlen); 898 aiov.iov_len = auio.uio_resid; 899 aiov.iov_base = (caddr_t)entry; 900 } 901 902 auio.uio_iov = &aiov; 903 auio.uio_iovcnt = 1; 904 auio.uio_rw = UIO_WRITE; 905 auio.uio_segflg = UIO_SYSSPACE; 906 auio.uio_td = (struct thread *)0; 907 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); 908 if (error) 909 goto out; 910 911 dp->i_size = roundup2(dp->i_size, dirblksize); 912 dp->i_flag |= IN_CHANGE; 913 914 out: 915 free(buf, M_TEMP); 916 return (error); 917 918 } 919 920 /* 921 * Write a directory entry after a call to namei, using the parameters 922 * that it left in nameidata. The argument ip is the inode which the new 923 * directory entry will refer to. Dvp is a pointer to the directory to 924 * be written, which was left locked by namei. Remaining parameters 925 * (dp->i_offset, dp->i_count) indicate how the space for the new 926 * entry is to be obtained. 927 */ 928 int 929 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp) 930 { 931 struct inode *dp; 932 struct ext2fs_direct_2 newdir; 933 int DIRBLKSIZ = ip->i_e2fs->e2fs_bsize; 934 int error; 935 936 937 #ifdef INVARIANTS 938 if ((cnp->cn_flags & SAVENAME) == 0) 939 panic("ext2_direnter: missing name"); 940 #endif 941 dp = VTOI(dvp); 942 newdir.e2d_ino = ip->i_number; 943 newdir.e2d_namlen = cnp->cn_namelen; 944 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 945 EXT2F_INCOMPAT_FTYPE)) 946 newdir.e2d_type = DTTOFT(IFTODT(ip->i_mode)); 947 else 948 newdir.e2d_type = EXT2_FT_UNKNOWN; 949 bcopy(cnp->cn_nameptr, newdir.e2d_name, (unsigned)cnp->cn_namelen + 1); 950 951 if (ext2_htree_has_idx(dp)) { 952 error = ext2_htree_add_entry(dvp, &newdir, cnp); 953 if (error) { 954 dp->i_flag &= ~IN_E3INDEX; 955 dp->i_flag |= IN_CHANGE | IN_UPDATE; 956 } 957 return (error); 958 } 959 960 if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) && 961 !ext2_htree_has_idx(dp)) { 962 if ((dp->i_size / DIRBLKSIZ) == 1 && 963 dp->i_offset == DIRBLKSIZ) { 964 /* 965 * Making indexed directory when one block is not 966 * enough to save all entries. 967 */ 968 return ext2_htree_create_index(dvp, cnp, &newdir); 969 } 970 } 971 972 /* 973 * If dp->i_count is 0, then namei could find no 974 * space in the directory. Here, dp->i_offset will 975 * be on a directory block boundary and we will write the 976 * new entry into a fresh block. 977 */ 978 if (dp->i_count == 0) 979 return ext2_add_first_entry(dvp, &newdir, cnp); 980 981 error = ext2_add_entry(dvp, &newdir); 982 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) 983 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, 984 cnp->cn_cred, cnp->cn_thread); 985 return (error); 986 } 987 988 /* 989 * Insert an entry into the directory block. 990 * Compact the contents. 991 */ 992 int 993 ext2_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry) 994 { 995 struct ext2fs_direct_2 *ep, *nep; 996 struct inode *dp; 997 struct buf *bp; 998 u_int dsize; 999 int error, loc, newentrysize, spacefree; 1000 char *dirbuf; 1001 1002 dp = VTOI(dvp); 1003 1004 /* 1005 * If dp->i_count is non-zero, then namei found space 1006 * for the new entry in the range dp->i_offset to 1007 * dp->i_offset + dp->i_count in the directory. 1008 * To use this space, we may have to compact the entries located 1009 * there, by copying them together towards the beginning of the 1010 * block, leaving the free space in one usable chunk at the end. 1011 */ 1012 1013 /* 1014 * Increase size of directory if entry eats into new space. 1015 * This should never push the size past a new multiple of 1016 * DIRBLKSIZE. 1017 * 1018 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. 1019 */ 1020 if (dp->i_offset + dp->i_count > dp->i_size) 1021 dp->i_size = dp->i_offset + dp->i_count; 1022 /* 1023 * Get the block containing the space for the new directory entry. 1024 */ 1025 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, 1026 &bp)) != 0) 1027 return (error); 1028 /* 1029 * Find space for the new entry. In the simple case, the entry at 1030 * offset base will have the space. If it does not, then namei 1031 * arranged that compacting the region dp->i_offset to 1032 * dp->i_offset + dp->i_count would yield the 1033 * space. 1034 */ 1035 newentrysize = EXT2_DIR_REC_LEN(entry->e2d_namlen); 1036 ep = (struct ext2fs_direct_2 *)dirbuf; 1037 dsize = EXT2_DIR_REC_LEN(ep->e2d_namlen); 1038 spacefree = ep->e2d_reclen - dsize; 1039 for (loc = ep->e2d_reclen; loc < dp->i_count; ) { 1040 nep = (struct ext2fs_direct_2 *)(dirbuf + loc); 1041 if (ep->e2d_ino) { 1042 /* trim the existing slot */ 1043 ep->e2d_reclen = dsize; 1044 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1045 } else { 1046 /* overwrite; nothing there; header is ours */ 1047 spacefree += dsize; 1048 } 1049 dsize = EXT2_DIR_REC_LEN(nep->e2d_namlen); 1050 spacefree += nep->e2d_reclen - dsize; 1051 loc += nep->e2d_reclen; 1052 bcopy((caddr_t)nep, (caddr_t)ep, dsize); 1053 } 1054 /* 1055 * Update the pointer fields in the previous entry (if any), 1056 * copy in the new entry, and write out the block. 1057 */ 1058 if (ep->e2d_ino == 0) { 1059 if (spacefree + dsize < newentrysize) 1060 panic("ext2_direnter: compact1"); 1061 entry->e2d_reclen = spacefree + dsize; 1062 } else { 1063 if (spacefree < newentrysize) 1064 panic("ext2_direnter: compact2"); 1065 entry->e2d_reclen = spacefree; 1066 ep->e2d_reclen = dsize; 1067 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1068 } 1069 bcopy((caddr_t)entry, (caddr_t)ep, (u_int)newentrysize); 1070 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1071 if (DOINGASYNC(dvp)) { 1072 bdwrite(bp); 1073 error = 0; 1074 } else { 1075 error = bwrite(bp); 1076 } 1077 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1078 return (error); 1079 } 1080 1081 /* 1082 * Remove a directory entry after a call to namei, using 1083 * the parameters which it left in nameidata. The entry 1084 * dp->i_offset contains the offset into the directory of the 1085 * entry to be eliminated. The dp->i_count field contains the 1086 * size of the previous record in the directory. If this 1087 * is 0, the first entry is being deleted, so we need only 1088 * zero the inode number to mark the entry as free. If the 1089 * entry is not the first in the directory, we must reclaim 1090 * the space of the now empty record by adding the record size 1091 * to the size of the previous entry. 1092 */ 1093 int 1094 ext2_dirremove(struct vnode *dvp, struct componentname *cnp) 1095 { 1096 struct inode *dp; 1097 struct ext2fs_direct_2 *ep, *rep; 1098 struct buf *bp; 1099 int error; 1100 1101 dp = VTOI(dvp); 1102 if (dp->i_count == 0) { 1103 /* 1104 * First entry in block: set d_ino to zero. 1105 */ 1106 if ((error = 1107 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, 1108 &bp)) != 0) 1109 return (error); 1110 ep->e2d_ino = 0; 1111 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1112 error = bwrite(bp); 1113 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1114 return (error); 1115 } 1116 /* 1117 * Collapse new free space into previous entry. 1118 */ 1119 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), 1120 (char **)&ep, &bp)) != 0) 1121 return (error); 1122 1123 /* Set 'rep' to the entry being removed. */ 1124 if (dp->i_count == 0) 1125 rep = ep; 1126 else 1127 rep = (struct ext2fs_direct_2 *)((char *)ep + ep->e2d_reclen); 1128 ep->e2d_reclen += rep->e2d_reclen; 1129 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1130 if (DOINGASYNC(dvp) && dp->i_count != 0) 1131 bdwrite(bp); 1132 else 1133 error = bwrite(bp); 1134 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1135 return (error); 1136 } 1137 1138 /* 1139 * Rewrite an existing directory entry to point at the inode 1140 * supplied. The parameters describing the directory entry are 1141 * set up by a call to namei. 1142 */ 1143 int 1144 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp) 1145 { 1146 struct buf *bp; 1147 struct ext2fs_direct_2 *ep; 1148 struct vnode *vdp = ITOV(dp); 1149 int error; 1150 1151 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, 1152 &bp)) != 0) 1153 return (error); 1154 ep->e2d_ino = ip->i_number; 1155 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 1156 EXT2F_INCOMPAT_FTYPE)) 1157 ep->e2d_type = DTTOFT(IFTODT(ip->i_mode)); 1158 else 1159 ep->e2d_type = EXT2_FT_UNKNOWN; 1160 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1161 error = bwrite(bp); 1162 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1163 return (error); 1164 } 1165 1166 /* 1167 * Check if a directory is empty or not. 1168 * Inode supplied must be locked. 1169 * 1170 * Using a struct dirtemplate here is not precisely 1171 * what we want, but better than using a struct direct. 1172 * 1173 * NB: does not handle corrupted directories. 1174 */ 1175 int 1176 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) 1177 { 1178 off_t off; 1179 struct dirtemplate dbuf; 1180 struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf; 1181 int error, namlen; 1182 ssize_t count; 1183 #define MINDIRSIZ (sizeof(struct dirtemplate) / 2) 1184 1185 for (off = 0; off < ip->i_size; off += dp->e2d_reclen) { 1186 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, 1187 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred, 1188 NOCRED, &count, (struct thread *)0); 1189 /* 1190 * Since we read MINDIRSIZ, residual must 1191 * be 0 unless we're at end of file. 1192 */ 1193 if (error || count != 0) 1194 return (0); 1195 /* avoid infinite loops */ 1196 if (dp->e2d_reclen == 0) 1197 return (0); 1198 /* skip empty entries */ 1199 if (dp->e2d_ino == 0) 1200 continue; 1201 /* accept only "." and ".." */ 1202 namlen = dp->e2d_namlen; 1203 if (namlen > 2) 1204 return (0); 1205 if (dp->e2d_name[0] != '.') 1206 return (0); 1207 /* 1208 * At this point namlen must be 1 or 2. 1209 * 1 implies ".", 2 implies ".." if second 1210 * char is also "." 1211 */ 1212 if (namlen == 1) 1213 continue; 1214 if (dp->e2d_name[1] == '.' && dp->e2d_ino == parentino) 1215 continue; 1216 return (0); 1217 } 1218 return (1); 1219 } 1220 1221 /* 1222 * Check if source directory is in the path of the target directory. 1223 * Target is supplied locked, source is unlocked. 1224 * The target is always vput before returning. 1225 */ 1226 int 1227 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred) 1228 { 1229 struct vnode *vp; 1230 int error, namlen; 1231 struct dirtemplate dirbuf; 1232 1233 vp = ITOV(target); 1234 if (target->i_number == source->i_number) { 1235 error = EEXIST; 1236 goto out; 1237 } 1238 if (target->i_number == EXT2_ROOTINO) { 1239 error = 0; 1240 goto out; 1241 } 1242 1243 for (;;) { 1244 if (vp->v_type != VDIR) { 1245 error = ENOTDIR; 1246 break; 1247 } 1248 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, 1249 sizeof(struct dirtemplate), (off_t)0, UIO_SYSSPACE, 1250 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, 1251 NULL); 1252 if (error != 0) 1253 break; 1254 namlen = dirbuf.dotdot_type; /* like ufs little-endian */ 1255 if (namlen != 2 || 1256 dirbuf.dotdot_name[0] != '.' || 1257 dirbuf.dotdot_name[1] != '.') { 1258 error = ENOTDIR; 1259 break; 1260 } 1261 if (dirbuf.dotdot_ino == source->i_number) { 1262 error = EINVAL; 1263 break; 1264 } 1265 if (dirbuf.dotdot_ino == EXT2_ROOTINO) 1266 break; 1267 vput(vp); 1268 if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino, 1269 LK_EXCLUSIVE, &vp)) != 0) { 1270 vp = NULL; 1271 break; 1272 } 1273 } 1274 1275 out: 1276 if (error == ENOTDIR) 1277 printf("checkpath: .. not a directory\n"); 1278 if (vp != NULL) 1279 vput(vp); 1280 return (error); 1281 }
Cache object: 87cf82d8c84d55f9fcf0eb0bfd1436ad
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