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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 * $FreeBSD$ 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/sdt.h> 57 #include <sys/sysctl.h> 58 59 #include <ufs/ufs/dir.h> 60 61 #include <fs/ext2fs/fs.h> 62 #include <fs/ext2fs/inode.h> 63 #include <fs/ext2fs/ext2_mount.h> 64 #include <fs/ext2fs/ext2fs.h> 65 #include <fs/ext2fs/ext2_dinode.h> 66 #include <fs/ext2fs/ext2_dir.h> 67 #include <fs/ext2fs/ext2_extern.h> 68 #include <fs/ext2fs/fs.h> 69 70 SDT_PROVIDER_DECLARE(ext2fs); 71 /* 72 * ext2fs trace probe: 73 * arg0: verbosity. Higher numbers give more verbose messages 74 * arg1: Textual message 75 */ 76 SDT_PROBE_DEFINE2(ext2fs, , lookup, trace, "int", "char*"); 77 SDT_PROBE_DEFINE4(ext2fs, , trace, ext2_dirbad_error, 78 "char*", "ino_t", "doff_t", "char*"); 79 SDT_PROBE_DEFINE5(ext2fs, , trace, ext2_dirbadentry_error, 80 "char*", "int", "uint32_t", "uint16_t", "uint8_t"); 81 82 static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 83 "EXT2FS filesystem"); 84 85 /* 86 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) 87 while it is the native blocksize in ext2fs - thus, a #define 88 is no longer appropriate 89 */ 90 #undef DIRBLKSIZ 91 92 static u_char ext2_ft_to_dt[] = { 93 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ 94 DT_REG, /* EXT2_FT_REG_FILE */ 95 DT_DIR, /* EXT2_FT_DIR */ 96 DT_CHR, /* EXT2_FT_CHRDEV */ 97 DT_BLK, /* EXT2_FT_BLKDEV */ 98 DT_FIFO, /* EXT2_FT_FIFO */ 99 DT_SOCK, /* EXT2_FT_SOCK */ 100 DT_LNK, /* EXT2_FT_SYMLINK */ 101 }; 102 #define FTTODT(ft) \ 103 ((ft) < nitems(ext2_ft_to_dt) ? ext2_ft_to_dt[(ft)] : DT_UNKNOWN) 104 105 static u_char dt_to_ext2_ft[] = { 106 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ 107 EXT2_FT_FIFO, /* DT_FIFO */ 108 EXT2_FT_CHRDEV, /* DT_CHR */ 109 EXT2_FT_UNKNOWN, /* unused */ 110 EXT2_FT_DIR, /* DT_DIR */ 111 EXT2_FT_UNKNOWN, /* unused */ 112 EXT2_FT_BLKDEV, /* DT_BLK */ 113 EXT2_FT_UNKNOWN, /* unused */ 114 EXT2_FT_REG_FILE, /* DT_REG */ 115 EXT2_FT_UNKNOWN, /* unused */ 116 EXT2_FT_SYMLINK, /* DT_LNK */ 117 EXT2_FT_UNKNOWN, /* unused */ 118 EXT2_FT_SOCK, /* DT_SOCK */ 119 EXT2_FT_UNKNOWN, /* unused */ 120 EXT2_FT_UNKNOWN, /* DT_WHT */ 121 }; 122 #define DTTOFT(dt) \ 123 ((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN) 124 125 static int ext2_check_direntry(struct vnode *dp, 126 struct ext2fs_direct_2 *de, int entryoffsetinblock); 127 static int ext2_is_dot_entry(struct componentname *cnp); 128 static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, 129 struct componentname *cnp, ino_t *dd_ino); 130 131 static int 132 ext2_is_dot_entry(struct componentname *cnp) 133 { 134 if (cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' && 135 (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0')) 136 return (1); 137 return (0); 138 } 139 140 /* 141 * Vnode op for reading directories. 142 */ 143 int 144 ext2_readdir(struct vop_readdir_args *ap) 145 { 146 struct vnode *vp = ap->a_vp; 147 struct uio *uio = ap->a_uio; 148 struct buf *bp; 149 struct inode *ip; 150 struct ext2fs_direct_2 *dp, *edp; 151 uint64_t *cookies; 152 struct dirent dstdp; 153 off_t offset, startoffset; 154 size_t readcnt, skipcnt; 155 ssize_t startresid; 156 u_int ncookies; 157 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->e2fs_bsize; 158 int error; 159 160 if (uio->uio_offset < 0) 161 return (EINVAL); 162 ip = VTOI(vp); 163 if (ap->a_ncookies != NULL) { 164 if (uio->uio_resid < 0) 165 ncookies = 0; 166 else 167 ncookies = uio->uio_resid; 168 if (uio->uio_offset >= ip->i_size) 169 ncookies = 0; 170 else if (ip->i_size - uio->uio_offset < ncookies) 171 ncookies = ip->i_size - uio->uio_offset; 172 ncookies = ncookies / (offsetof(struct ext2fs_direct_2, 173 e2d_namlen) + 4) + 1; 174 cookies = malloc(ncookies * sizeof(*cookies), M_TEMP, M_WAITOK); 175 *ap->a_ncookies = ncookies; 176 *ap->a_cookies = cookies; 177 } else { 178 ncookies = 0; 179 cookies = NULL; 180 } 181 offset = startoffset = uio->uio_offset; 182 startresid = uio->uio_resid; 183 error = 0; 184 while (error == 0 && uio->uio_resid > 0 && 185 uio->uio_offset < ip->i_size) { 186 error = ext2_blkatoff(vp, uio->uio_offset, NULL, &bp); 187 if (error) 188 break; 189 if (bp->b_offset + bp->b_bcount > ip->i_size) 190 readcnt = ip->i_size - bp->b_offset; 191 else 192 readcnt = bp->b_bcount; 193 skipcnt = (size_t)(uio->uio_offset - bp->b_offset) & 194 ~(size_t)(DIRBLKSIZ - 1); 195 offset = bp->b_offset + skipcnt; 196 dp = (struct ext2fs_direct_2 *)&bp->b_data[skipcnt]; 197 edp = (struct ext2fs_direct_2 *)&bp->b_data[readcnt]; 198 while (error == 0 && uio->uio_resid > 0 && dp < edp) { 199 if (le16toh(dp->e2d_reclen) <= offsetof(struct ext2fs_direct_2, 200 e2d_namlen) || (caddr_t)dp + le16toh(dp->e2d_reclen) > 201 (caddr_t)edp) { 202 error = EIO; 203 break; 204 } 205 /*- 206 * "New" ext2fs directory entries differ in 3 ways 207 * from ufs on-disk ones: 208 * - the name is not necessarily NUL-terminated. 209 * - the file type field always exists and always 210 * follows the name length field. 211 * - the file type is encoded in a different way. 212 * 213 * "Old" ext2fs directory entries need no special 214 * conversions, since they are binary compatible 215 * with "new" entries having a file type of 0 (i.e., 216 * EXT2_FT_UNKNOWN). Splitting the old name length 217 * field didn't make a mess like it did in ufs, 218 * because ext2fs uses a machine-independent disk 219 * layout. 220 */ 221 dstdp.d_namlen = dp->e2d_namlen; 222 dstdp.d_type = FTTODT(dp->e2d_type); 223 if (offsetof(struct ext2fs_direct_2, e2d_namlen) + 224 dstdp.d_namlen > le16toh(dp->e2d_reclen)) { 225 error = EIO; 226 break; 227 } 228 if (offset < startoffset || le32toh(dp->e2d_ino) == 0) 229 goto nextentry; 230 dstdp.d_fileno = le32toh(dp->e2d_ino); 231 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); 232 bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen); 233 /* NOTE: d_off is the offset of the *next* entry. */ 234 dstdp.d_off = offset + le16toh(dp->e2d_reclen); 235 dirent_terminate(&dstdp); 236 if (dstdp.d_reclen > uio->uio_resid) { 237 if (uio->uio_resid == startresid) 238 error = EINVAL; 239 else 240 error = EJUSTRETURN; 241 break; 242 } 243 /* Advance dp. */ 244 error = uiomove((caddr_t)&dstdp, dstdp.d_reclen, uio); 245 if (error) 246 break; 247 if (cookies != NULL) { 248 KASSERT(ncookies > 0, 249 ("ext2_readdir: cookies buffer too small")); 250 *cookies = offset + le16toh(dp->e2d_reclen); 251 cookies++; 252 ncookies--; 253 } 254 nextentry: 255 offset += le16toh(dp->e2d_reclen); 256 dp = (struct ext2fs_direct_2 *)((caddr_t)dp + 257 le16toh(dp->e2d_reclen)); 258 } 259 bqrelse(bp); 260 uio->uio_offset = offset; 261 } 262 /* We need to correct uio_offset. */ 263 uio->uio_offset = offset; 264 if (error == EJUSTRETURN) 265 error = 0; 266 if (ap->a_ncookies != NULL) { 267 if (error == 0) { 268 *ap->a_ncookies -= ncookies; 269 } else { 270 free(*ap->a_cookies, M_TEMP); 271 *ap->a_ncookies = 0; 272 *ap->a_cookies = NULL; 273 } 274 } 275 if (error == 0 && ap->a_eofflag) 276 *ap->a_eofflag = ip->i_size <= uio->uio_offset; 277 return (error); 278 } 279 280 /* 281 * Convert a component of a pathname into a pointer to a locked inode. 282 * This is a very central and rather complicated routine. 283 * If the file system is not maintained in a strict tree hierarchy, 284 * this can result in a deadlock situation (see comments in code below). 285 * 286 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending 287 * on whether the name is to be looked up, created, renamed, or deleted. 288 * When CREATE, RENAME, or DELETE is specified, information usable in 289 * creating, renaming, or deleting a directory entry may be calculated. 290 * If flag has LOCKPARENT or'ed into it and the target of the pathname 291 * exists, lookup returns both the target and its parent directory locked. 292 * When creating or renaming and LOCKPARENT is specified, the target may 293 * not be ".". When deleting and LOCKPARENT is specified, the target may 294 * be "."., but the caller must check to ensure it does an vrele and vput 295 * instead of two vputs. 296 * 297 * Overall outline of ext2_lookup: 298 * 299 * search for name in directory, to found or notfound 300 * notfound: 301 * if creating, return locked directory, leaving info on available slots 302 * else return error 303 * found: 304 * if at end of path and deleting, return information to allow delete 305 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target 306 * inode and return info to allow rewrite 307 * if not at end, add name to cache; if at end and neither creating 308 * nor deleting, add name to cache 309 */ 310 int 311 ext2_lookup(struct vop_cachedlookup_args *ap) 312 { 313 314 return (ext2_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL)); 315 } 316 317 static int 318 ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp, 319 ino_t *dd_ino) 320 { 321 struct inode *dp; /* inode for directory being searched */ 322 struct buf *bp; /* a buffer of directory entries */ 323 struct ext2fs_direct_2 *ep; /* the current directory entry */ 324 int entryoffsetinblock; /* offset of ep in bp's buffer */ 325 struct ext2fs_searchslot ss; 326 doff_t i_diroff; /* cached i_diroff value */ 327 doff_t i_offset; /* cached i_offset value */ 328 int numdirpasses; /* strategy for directory search */ 329 doff_t endsearch; /* offset to end directory search */ 330 doff_t prevoff; /* prev entry dp->i_offset */ 331 struct vnode *pdp; /* saved dp during symlink work */ 332 struct vnode *tdp; /* returned by VFS_VGET */ 333 doff_t enduseful; /* pointer past last used dir slot */ 334 u_long bmask; /* block offset mask */ 335 int error; 336 struct ucred *cred = cnp->cn_cred; 337 int flags = cnp->cn_flags; 338 int nameiop = cnp->cn_nameiop; 339 ino_t ino, ino1; 340 int ltype; 341 int entry_found = 0; 342 343 int DIRBLKSIZ = VTOI(vdp)->i_e2fs->e2fs_bsize; 344 345 if (vpp != NULL) 346 *vpp = NULL; 347 348 dp = VTOI(vdp); 349 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; 350 restart: 351 bp = NULL; 352 ss.slotoffset = -1; 353 354 /* 355 * We now have a segment name to search for, and a directory to search. 356 * 357 * Suppress search for slots unless creating 358 * file and at end of pathname, in which case 359 * we watch for a place to put the new file in 360 * case it doesn't already exist. 361 */ 362 i_diroff = dp->i_diroff; 363 ss.slotstatus = FOUND; 364 ss.slotfreespace = ss.slotsize = ss.slotneeded = 0; 365 if ((nameiop == CREATE || nameiop == RENAME) && 366 (flags & ISLASTCN)) { 367 ss.slotstatus = NONE; 368 ss.slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); 369 /* 370 * was ss.slotneeded = (sizeof(struct direct) - MAXNAMLEN + 371 * cnp->cn_namelen + 3) &~ 3; 372 */ 373 } 374 /* 375 * Try to lookup dir entry using htree directory index. 376 * 377 * If we got an error or we want to find '.' or '..' entry, 378 * we will fall back to linear search. 379 */ 380 if (!ext2_is_dot_entry(cnp) && ext2_htree_has_idx(dp)) { 381 numdirpasses = 1; 382 entryoffsetinblock = 0; 383 switch (ext2_htree_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen, 384 &bp, &entryoffsetinblock, &i_offset, &prevoff, 385 &enduseful, &ss)) { 386 case 0: 387 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 388 (i_offset & bmask)); 389 goto foundentry; 390 case ENOENT: 391 i_offset = roundup2(dp->i_size, DIRBLKSIZ); 392 goto notfound; 393 default: 394 /* 395 * Something failed; just fallback to do a linear 396 * search. 397 */ 398 break; 399 } 400 } 401 402 /* 403 * If there is cached information on a previous search of 404 * this directory, pick up where we last left off. 405 * We cache only lookups as these are the most common 406 * and have the greatest payoff. Caching CREATE has little 407 * benefit as it usually must search the entire directory 408 * to determine that the entry does not exist. Caching the 409 * location of the last DELETE or RENAME has not reduced 410 * profiling time and hence has been removed in the interest 411 * of simplicity. 412 */ 413 if (nameiop != LOOKUP || i_diroff == 0 || 414 i_diroff > dp->i_size) { 415 entryoffsetinblock = 0; 416 i_offset = 0; 417 numdirpasses = 1; 418 } else { 419 i_offset = i_diroff; 420 if ((entryoffsetinblock = i_offset & bmask) && 421 (error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, 422 &bp))) 423 return (error); 424 numdirpasses = 2; 425 nchstats.ncs_2passes++; 426 } 427 prevoff = i_offset; 428 endsearch = roundup2(dp->i_size, DIRBLKSIZ); 429 enduseful = 0; 430 431 searchloop: 432 while (i_offset < endsearch) { 433 /* 434 * If necessary, get the next directory block. 435 */ 436 if (bp != NULL) 437 brelse(bp); 438 error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, &bp); 439 if (error != 0) 440 return (error); 441 442 entryoffsetinblock = 0; 443 if (ss.slotstatus == NONE) { 444 ss.slotoffset = -1; 445 ss.slotfreespace = 0; 446 } 447 448 error = ext2_search_dirblock(dp, bp->b_data, &entry_found, 449 cnp->cn_nameptr, cnp->cn_namelen, 450 &entryoffsetinblock, &i_offset, &prevoff, 451 &enduseful, &ss); 452 if (error != 0) { 453 brelse(bp); 454 return (error); 455 } 456 if (entry_found) { 457 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 458 (entryoffsetinblock & bmask)); 459 foundentry: 460 ino = le32toh(ep->e2d_ino); 461 goto found; 462 } 463 } 464 notfound: 465 /* 466 * If we started in the middle of the directory and failed 467 * to find our target, we must check the beginning as well. 468 */ 469 if (numdirpasses == 2) { 470 numdirpasses--; 471 i_offset = 0; 472 endsearch = i_diroff; 473 goto searchloop; 474 } 475 if (bp != NULL) 476 brelse(bp); 477 /* 478 * If creating, and at end of pathname and current 479 * directory has not been removed, then can consider 480 * allowing file to be created. 481 */ 482 if ((nameiop == CREATE || nameiop == RENAME) && 483 (flags & ISLASTCN) && dp->i_nlink != 0) { 484 /* 485 * Access for write is interpreted as allowing 486 * creation of files in the directory. 487 */ 488 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0) 489 return (error); 490 /* 491 * Return an indication of where the new directory 492 * entry should be put. If we didn't find a slot, 493 * then set dp->i_count to 0 indicating 494 * that the new slot belongs at the end of the 495 * directory. If we found a slot, then the new entry 496 * can be put in the range from dp->i_offset to 497 * dp->i_offset + dp->i_count. 498 */ 499 if (ss.slotstatus == NONE) { 500 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); 501 dp->i_count = 0; 502 enduseful = dp->i_offset; 503 } else { 504 dp->i_offset = ss.slotoffset; 505 dp->i_count = ss.slotsize; 506 if (enduseful < ss.slotoffset + ss.slotsize) 507 enduseful = ss.slotoffset + ss.slotsize; 508 } 509 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ); 510 /* 511 * We return with the directory locked, so that 512 * the parameters we set up above will still be 513 * valid if we actually decide to do a direnter(). 514 * We return ni_vp == NULL to indicate that the entry 515 * does not currently exist; we leave a pointer to 516 * the (locked) directory inode in ndp->ni_dvp. 517 * 518 * NB - if the directory is unlocked, then this 519 * information cannot be used. 520 */ 521 return (EJUSTRETURN); 522 } 523 /* 524 * Insert name into cache (as non-existent) if appropriate. 525 */ 526 if ((cnp->cn_flags & MAKEENTRY) != 0) 527 cache_enter(vdp, NULL, cnp); 528 return (ENOENT); 529 530 found: 531 if (dd_ino != NULL) 532 *dd_ino = ino; 533 if (numdirpasses == 2) 534 nchstats.ncs_pass2++; 535 /* 536 * Check that directory length properly reflects presence 537 * of this entry. 538 */ 539 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen) > 540 dp->i_size) { 541 ext2_dirbad(dp, i_offset, "i_size too small"); 542 dp->i_size = entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen); 543 dp->i_flag |= IN_CHANGE | IN_UPDATE; 544 } 545 brelse(bp); 546 547 /* 548 * Found component in pathname. 549 * If the final component of path name, save information 550 * in the cache as to where the entry was found. 551 */ 552 if ((flags & ISLASTCN) && nameiop == LOOKUP) 553 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ); 554 /* 555 * If deleting, and at end of pathname, return 556 * parameters which can be used to remove file. 557 */ 558 if (nameiop == DELETE && (flags & ISLASTCN)) { 559 if (flags & LOCKPARENT) 560 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__); 561 /* 562 * Write access to directory required to delete files. 563 */ 564 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0) 565 return (error); 566 /* 567 * Return pointer to current entry in dp->i_offset, 568 * and distance past previous entry (if there 569 * is a previous entry in this block) in dp->i_count. 570 * Save directory inode pointer in ndp->ni_dvp for dirremove(). 571 * 572 * Technically we shouldn't be setting these in the 573 * WANTPARENT case (first lookup in rename()), but any 574 * lookups that will result in directory changes will 575 * overwrite these. 576 */ 577 dp->i_offset = i_offset; 578 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) 579 dp->i_count = 0; 580 else 581 dp->i_count = dp->i_offset - prevoff; 582 if (dd_ino != NULL) 583 return (0); 584 if (dp->i_number == ino) { 585 VREF(vdp); 586 *vpp = vdp; 587 return (0); 588 } 589 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, 590 &tdp)) != 0) 591 return (error); 592 /* 593 * If directory is "sticky", then user must own 594 * the directory, or the file in it, else she 595 * may not delete it (unless she's root). This 596 * implements append-only directories. 597 */ 598 if ((dp->i_mode & ISVTX) && 599 cred->cr_uid != 0 && 600 cred->cr_uid != dp->i_uid && 601 VTOI(tdp)->i_uid != cred->cr_uid) { 602 vput(tdp); 603 return (EPERM); 604 } 605 *vpp = tdp; 606 return (0); 607 } 608 609 /* 610 * If rewriting (RENAME), return the inode and the 611 * information required to rewrite the present directory 612 * Must get inode of directory entry to verify it's a 613 * regular file, or empty directory. 614 */ 615 if (nameiop == RENAME && (flags & ISLASTCN)) { 616 if ((error = VOP_ACCESS(vdp, VWRITE, cred, curthread)) != 0) 617 return (error); 618 /* 619 * Careful about locking second inode. 620 * This can only occur if the target is ".". 621 */ 622 dp->i_offset = i_offset; 623 if (dp->i_number == ino) 624 return (EISDIR); 625 if (dd_ino != NULL) 626 return (0); 627 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, 628 &tdp)) != 0) 629 return (error); 630 *vpp = tdp; 631 return (0); 632 } 633 if (dd_ino != NULL) 634 return (0); 635 636 /* 637 * Step through the translation in the name. We do not `vput' the 638 * directory because we may need it again if a symbolic link 639 * is relative to the current directory. Instead we save it 640 * unlocked as "pdp". We must get the target inode before unlocking 641 * the directory to insure that the inode will not be removed 642 * before we get it. We prevent deadlock by always fetching 643 * inodes from the root, moving down the directory tree. Thus 644 * when following backward pointers ".." we must unlock the 645 * parent directory before getting the requested directory. 646 * There is a potential race condition here if both the current 647 * and parent directories are removed before the VFS_VGET for the 648 * inode associated with ".." returns. We hope that this occurs 649 * infrequently since we cannot avoid this race condition without 650 * implementing a sophisticated deadlock detection algorithm. 651 * Note also that this simple deadlock detection scheme will not 652 * work if the file system has any hard links other than ".." 653 * that point backwards in the directory structure. 654 */ 655 pdp = vdp; 656 if (flags & ISDOTDOT) { 657 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp); 658 if (VN_IS_DOOMED(pdp)) { 659 if (error == 0) 660 vput(tdp); 661 error = ENOENT; 662 } 663 if (error) 664 return (error); 665 /* 666 * Recheck that ".." entry in the vdp directory points 667 * to the inode we looked up before vdp lock was 668 * dropped. 669 */ 670 error = ext2_lookup_ino(pdp, NULL, cnp, &ino1); 671 if (error) { 672 vput(tdp); 673 return (error); 674 } 675 if (ino1 != ino) { 676 vput(tdp); 677 goto restart; 678 } 679 *vpp = tdp; 680 } else if (dp->i_number == ino) { 681 VREF(vdp); /* we want ourself, ie "." */ 682 /* 683 * When we lookup "." we still can be asked to lock it 684 * differently. 685 */ 686 ltype = cnp->cn_lkflags & LK_TYPE_MASK; 687 if (ltype != VOP_ISLOCKED(vdp)) { 688 if (ltype == LK_EXCLUSIVE) 689 vn_lock(vdp, LK_UPGRADE | LK_RETRY); 690 else /* if (ltype == LK_SHARED) */ 691 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY); 692 } 693 *vpp = vdp; 694 } else { 695 if ((error = VFS_VGET(vdp->v_mount, ino, cnp->cn_lkflags, 696 &tdp)) != 0) 697 return (error); 698 *vpp = tdp; 699 } 700 701 /* 702 * Insert name into cache if appropriate. 703 */ 704 if (cnp->cn_flags & MAKEENTRY) 705 cache_enter(vdp, *vpp, cnp); 706 return (0); 707 } 708 709 int 710 ext2_search_dirblock(struct inode *ip, void *data, int *foundp, 711 const char *name, int namelen, int *entryoffsetinblockp, 712 doff_t *offp, doff_t *prevoffp, doff_t *endusefulp, 713 struct ext2fs_searchslot *ssp) 714 { 715 struct vnode *vdp; 716 struct ext2fs_direct_2 *ep, *top; 717 uint32_t bsize = ip->i_e2fs->e2fs_bsize; 718 int offset = *entryoffsetinblockp; 719 int namlen; 720 721 vdp = ITOV(ip); 722 723 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 724 top = (struct ext2fs_direct_2 *)((char *)data + bsize); 725 while (ep < top) { 726 if (ext2_check_direntry(vdp, ep, offset)) { 727 int i; 728 729 ext2_dirbad(ip, *offp, "mangled entry"); 730 i = bsize - (offset & (bsize - 1)); 731 *offp += i; 732 offset += i; 733 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 734 continue; 735 } 736 737 /* 738 * If an appropriate sized slot has not yet been found, 739 * check to see if one is available. Also accumulate space 740 * in the current block so that we can determine if 741 * compaction is viable. 742 */ 743 if (ssp->slotstatus != FOUND) { 744 int size = le16toh(ep->e2d_reclen); 745 746 if (ep->e2d_ino != 0) 747 size -= EXT2_DIR_REC_LEN(ep->e2d_namlen); 748 else if (ext2_is_dirent_tail(ip, ep)) 749 size -= sizeof(struct ext2fs_direct_tail); 750 if (size > 0) { 751 if (size >= ssp->slotneeded) { 752 ssp->slotstatus = FOUND; 753 ssp->slotoffset = *offp; 754 ssp->slotsize = le16toh(ep->e2d_reclen); 755 } else if (ssp->slotstatus == NONE) { 756 ssp->slotfreespace += size; 757 if (ssp->slotoffset == -1) 758 ssp->slotoffset = *offp; 759 if (ssp->slotfreespace >= ssp->slotneeded) { 760 ssp->slotstatus = COMPACT; 761 ssp->slotsize = *offp + 762 le16toh(ep->e2d_reclen) - 763 ssp->slotoffset; 764 } 765 } 766 } 767 } 768 /* 769 * Check for a name match. 770 */ 771 if (ep->e2d_ino != 0) { 772 namlen = ep->e2d_namlen; 773 if (namlen == namelen && 774 !bcmp(name, ep->e2d_name, (unsigned)namlen)) { 775 /* 776 * Save directory entry's inode number and 777 * reclen in ndp->ni_ufs area, and release 778 * directory buffer. 779 */ 780 *foundp = 1; 781 return (0); 782 } 783 } 784 *prevoffp = *offp; 785 *offp += le16toh(ep->e2d_reclen); 786 offset += le16toh(ep->e2d_reclen); 787 *entryoffsetinblockp = offset; 788 if (ep->e2d_ino != 0) 789 *endusefulp = *offp; 790 /* 791 * Get pointer to the next entry. 792 */ 793 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 794 } 795 796 return (0); 797 } 798 799 void 800 ext2_dirbad(struct inode *ip, doff_t offset, char *how) 801 { 802 struct mount *mp; 803 804 mp = ITOV(ip)->v_mount; 805 if ((mp->mnt_flag & MNT_RDONLY) == 0) 806 panic("ext2_dirbad: %s: bad dir ino %ju at offset %ld: %s\n", 807 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, 808 (long)offset, how); 809 else 810 SDT_PROBE4(ext2fs, , trace, ext2_dirbad_error, 811 mp->mnt_stat.f_mntonname, ip->i_number, offset, how); 812 } 813 814 /* 815 * Do consistency checking on a directory entry: 816 * record length must be multiple of 4 817 * entry must fit in rest of its DIRBLKSIZ block 818 * record must be large enough to contain entry 819 * name is not longer than MAXNAMLEN 820 * name must be as long as advertised, and null terminated 821 */ 822 static int 823 ext2_check_direntry(struct vnode *dp, struct ext2fs_direct_2 *de, 824 int entryoffsetinblock) 825 { 826 struct m_ext2fs *fs = VTOI(dp)->i_e2fs; 827 char *error_msg = NULL; 828 829 if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(1)) 830 error_msg = "rec_len is smaller than minimal"; 831 else if (le16toh(de->e2d_reclen) % 4 != 0) 832 error_msg = "rec_len % 4 != 0"; 833 else if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(de->e2d_namlen)) 834 error_msg = "reclen is too small for name_len"; 835 else if (entryoffsetinblock + le16toh(de->e2d_reclen)> fs->e2fs_bsize) 836 error_msg = "directory entry across blocks"; 837 else if (le32toh(de->e2d_ino) > fs->e2fs->e2fs_icount) 838 error_msg = "directory entry inode out of bounds"; 839 840 if (error_msg != NULL) { 841 SDT_PROBE5(ext2fs, , trace, ext2_dirbadentry_error, 842 error_msg, entryoffsetinblock, 843 le32toh(de->e2d_ino), le16toh(de->e2d_reclen), 844 de->e2d_namlen); 845 } 846 return (error_msg == NULL ? 0 : EINVAL); 847 } 848 849 /* 850 * Insert an entry into the fresh directory block. 851 * Initialize entry tail if the metadata_csum feature is turned on. 852 */ 853 static int 854 ext2_add_first_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry, 855 struct componentname *cnp) 856 { 857 struct inode *dp; 858 struct iovec aiov; 859 struct uio auio; 860 char* buf = NULL; 861 int dirblksize, error; 862 863 dp = VTOI(dvp); 864 dirblksize = dp->i_e2fs->e2fs_bsize; 865 866 if (dp->i_offset & (dirblksize - 1)) 867 panic("ext2_add_first_entry: bad directory offset"); 868 869 if (EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs, 870 EXT2F_ROCOMPAT_METADATA_CKSUM)) { 871 entry->e2d_reclen = htole16(dirblksize - 872 sizeof(struct ext2fs_direct_tail)); 873 buf = malloc(dirblksize, M_TEMP, M_WAITOK); 874 memcpy(buf, entry, EXT2_DIR_REC_LEN(entry->e2d_namlen)); 875 ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, dirblksize)); 876 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)buf); 877 878 auio.uio_offset = dp->i_offset; 879 auio.uio_resid = dirblksize; 880 aiov.iov_len = auio.uio_resid; 881 aiov.iov_base = (caddr_t)buf; 882 } else { 883 entry->e2d_reclen = htole16(dirblksize); 884 auio.uio_offset = dp->i_offset; 885 auio.uio_resid = EXT2_DIR_REC_LEN(entry->e2d_namlen); 886 aiov.iov_len = auio.uio_resid; 887 aiov.iov_base = (caddr_t)entry; 888 } 889 890 auio.uio_iov = &aiov; 891 auio.uio_iovcnt = 1; 892 auio.uio_rw = UIO_WRITE; 893 auio.uio_segflg = UIO_SYSSPACE; 894 auio.uio_td = (struct thread *)0; 895 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); 896 if (error) 897 goto out; 898 899 dp->i_size = roundup2(dp->i_size, dirblksize); 900 dp->i_flag |= IN_CHANGE; 901 902 out: 903 free(buf, M_TEMP); 904 return (error); 905 906 } 907 908 /* 909 * Write a directory entry after a call to namei, using the parameters 910 * that it left in nameidata. The argument ip is the inode which the new 911 * directory entry will refer to. Dvp is a pointer to the directory to 912 * be written, which was left locked by namei. Remaining parameters 913 * (dp->i_offset, dp->i_count) indicate how the space for the new 914 * entry is to be obtained. 915 */ 916 int 917 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp) 918 { 919 struct inode *dp; 920 struct ext2fs_direct_2 newdir; 921 int DIRBLKSIZ = ip->i_e2fs->e2fs_bsize; 922 int error; 923 924 dp = VTOI(dvp); 925 newdir.e2d_ino = htole32(ip->i_number); 926 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 927 EXT2F_INCOMPAT_FTYPE)) { 928 newdir.e2d_namlen = cnp->cn_namelen; 929 newdir.e2d_type = DTTOFT(IFTODT(ip->i_mode)); 930 } else 931 newdir.e2d_namlen = htole16(cnp->cn_namelen); 932 933 bcopy(cnp->cn_nameptr, newdir.e2d_name, (unsigned)cnp->cn_namelen + 1); 934 935 if (ext2_htree_has_idx(dp)) { 936 error = ext2_htree_add_entry(dvp, &newdir, cnp); 937 if (error) { 938 dp->i_flag &= ~IN_E3INDEX; 939 dp->i_flag |= IN_CHANGE | IN_UPDATE; 940 } 941 return (error); 942 } 943 944 if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) && 945 !ext2_htree_has_idx(dp)) { 946 if ((dp->i_size / DIRBLKSIZ) == 1 && 947 dp->i_offset == DIRBLKSIZ) { 948 /* 949 * Making indexed directory when one block is not 950 * enough to save all entries. 951 */ 952 return ext2_htree_create_index(dvp, cnp, &newdir); 953 } 954 } 955 956 /* 957 * If dp->i_count is 0, then namei could find no 958 * space in the directory. Here, dp->i_offset will 959 * be on a directory block boundary and we will write the 960 * new entry into a fresh block. 961 */ 962 if (dp->i_count == 0) 963 return ext2_add_first_entry(dvp, &newdir, cnp); 964 965 error = ext2_add_entry(dvp, &newdir); 966 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) 967 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, 968 cnp->cn_cred, curthread); 969 return (error); 970 } 971 972 /* 973 * Insert an entry into the directory block. 974 * Compact the contents. 975 */ 976 int 977 ext2_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry) 978 { 979 struct ext2fs_direct_2 *ep, *nep; 980 struct inode *dp; 981 struct buf *bp; 982 u_int dsize; 983 int error, loc, newentrysize, spacefree; 984 char *dirbuf; 985 986 dp = VTOI(dvp); 987 988 /* 989 * If dp->i_count is non-zero, then namei found space 990 * for the new entry in the range dp->i_offset to 991 * dp->i_offset + dp->i_count in the directory. 992 * To use this space, we may have to compact the entries located 993 * there, by copying them together towards the beginning of the 994 * block, leaving the free space in one usable chunk at the end. 995 */ 996 997 /* 998 * Increase size of directory if entry eats into new space. 999 * This should never push the size past a new multiple of 1000 * DIRBLKSIZE. 1001 * 1002 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. 1003 */ 1004 if (dp->i_offset + dp->i_count > dp->i_size) 1005 dp->i_size = dp->i_offset + dp->i_count; 1006 /* 1007 * Get the block containing the space for the new directory entry. 1008 */ 1009 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, 1010 &bp)) != 0) 1011 return (error); 1012 /* 1013 * Find space for the new entry. In the simple case, the entry at 1014 * offset base will have the space. If it does not, then namei 1015 * arranged that compacting the region dp->i_offset to 1016 * dp->i_offset + dp->i_count would yield the 1017 * space. 1018 */ 1019 newentrysize = EXT2_DIR_REC_LEN(entry->e2d_namlen); 1020 ep = (struct ext2fs_direct_2 *)dirbuf; 1021 dsize = EXT2_DIR_REC_LEN(ep->e2d_namlen); 1022 spacefree = le16toh(ep->e2d_reclen) - dsize; 1023 for (loc = le16toh(ep->e2d_reclen); loc < dp->i_count; ) { 1024 nep = (struct ext2fs_direct_2 *)(dirbuf + loc); 1025 if (le32toh(ep->e2d_ino)) { 1026 /* trim the existing slot */ 1027 ep->e2d_reclen = htole16(dsize); 1028 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1029 } else { 1030 /* overwrite; nothing there; header is ours */ 1031 spacefree += dsize; 1032 } 1033 dsize = EXT2_DIR_REC_LEN(nep->e2d_namlen); 1034 spacefree += le16toh(nep->e2d_reclen) - dsize; 1035 loc += le16toh(nep->e2d_reclen); 1036 bcopy((caddr_t)nep, (caddr_t)ep, dsize); 1037 } 1038 /* 1039 * Update the pointer fields in the previous entry (if any), 1040 * copy in the new entry, and write out the block. 1041 */ 1042 if (ep->e2d_ino == 0) { 1043 if (spacefree + dsize < newentrysize) 1044 panic("ext2_direnter: compact1"); 1045 entry->e2d_reclen = htole16(spacefree + dsize); 1046 } else { 1047 if (spacefree < newentrysize) 1048 panic("ext2_direnter: compact2"); 1049 entry->e2d_reclen = htole16(spacefree); 1050 ep->e2d_reclen = htole16(dsize); 1051 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1052 } 1053 bcopy((caddr_t)entry, (caddr_t)ep, (u_int)newentrysize); 1054 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1055 if (DOINGASYNC(dvp)) { 1056 bdwrite(bp); 1057 error = 0; 1058 } else { 1059 error = bwrite(bp); 1060 } 1061 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1062 return (error); 1063 } 1064 1065 /* 1066 * Remove a directory entry after a call to namei, using 1067 * the parameters which it left in nameidata. The entry 1068 * dp->i_offset contains the offset into the directory of the 1069 * entry to be eliminated. The dp->i_count field contains the 1070 * size of the previous record in the directory. If this 1071 * is 0, the first entry is being deleted, so we need only 1072 * zero the inode number to mark the entry as free. If the 1073 * entry is not the first in the directory, we must reclaim 1074 * the space of the now empty record by adding the record size 1075 * to the size of the previous entry. 1076 */ 1077 int 1078 ext2_dirremove(struct vnode *dvp, struct componentname *cnp) 1079 { 1080 struct inode *dp; 1081 struct ext2fs_direct_2 *ep, *rep; 1082 struct buf *bp; 1083 int error; 1084 1085 dp = VTOI(dvp); 1086 if (dp->i_count == 0) { 1087 /* 1088 * First entry in block: set d_ino to zero. 1089 */ 1090 if ((error = 1091 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, 1092 &bp)) != 0) 1093 return (error); 1094 ep->e2d_ino = 0; 1095 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1096 error = bwrite(bp); 1097 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1098 return (error); 1099 } 1100 /* 1101 * Collapse new free space into previous entry. 1102 */ 1103 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), 1104 (char **)&ep, &bp)) != 0) 1105 return (error); 1106 1107 /* Set 'rep' to the entry being removed. */ 1108 if (dp->i_count == 0) 1109 rep = ep; 1110 else 1111 rep = (struct ext2fs_direct_2 *)((char *)ep + 1112 le16toh(ep->e2d_reclen)); 1113 ep->e2d_reclen += rep->e2d_reclen; 1114 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1115 if (DOINGASYNC(dvp) && dp->i_count != 0) 1116 bdwrite(bp); 1117 else 1118 error = bwrite(bp); 1119 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1120 return (error); 1121 } 1122 1123 /* 1124 * Rewrite an existing directory entry to point at the inode 1125 * supplied. The parameters describing the directory entry are 1126 * set up by a call to namei. 1127 */ 1128 int 1129 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp) 1130 { 1131 struct buf *bp; 1132 struct ext2fs_direct_2 *ep; 1133 struct vnode *vdp = ITOV(dp); 1134 int error; 1135 1136 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, 1137 &bp)) != 0) 1138 return (error); 1139 ep->e2d_ino = htole32(ip->i_number); 1140 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 1141 EXT2F_INCOMPAT_FTYPE)) 1142 ep->e2d_type = DTTOFT(IFTODT(ip->i_mode)); 1143 else 1144 ep->e2d_type = EXT2_FT_UNKNOWN; 1145 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1146 error = bwrite(bp); 1147 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1148 return (error); 1149 } 1150 1151 /* 1152 * Check if a directory is empty or not. 1153 * Inode supplied must be locked. 1154 * 1155 * Using a struct dirtemplate here is not precisely 1156 * what we want, but better than using a struct direct. 1157 * 1158 * NB: does not handle corrupted directories. 1159 */ 1160 int 1161 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) 1162 { 1163 off_t off; 1164 struct dirtemplate dbuf; 1165 struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf; 1166 int error, namlen; 1167 ssize_t count; 1168 #define MINDIRSIZ (sizeof(struct dirtemplate) / 2) 1169 1170 for (off = 0; off < ip->i_size; off += le16toh(dp->e2d_reclen)) { 1171 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, 1172 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred, 1173 NOCRED, &count, (struct thread *)0); 1174 /* 1175 * Since we read MINDIRSIZ, residual must 1176 * be 0 unless we're at end of file. 1177 */ 1178 if (error || count != 0) 1179 return (0); 1180 /* avoid infinite loops */ 1181 if (dp->e2d_reclen == 0) 1182 return (0); 1183 /* skip empty entries */ 1184 if (dp->e2d_ino == 0) 1185 continue; 1186 /* accept only "." and ".." */ 1187 namlen = dp->e2d_namlen; 1188 if (namlen > 2) 1189 return (0); 1190 if (dp->e2d_name[0] != '.') 1191 return (0); 1192 /* 1193 * At this point namlen must be 1 or 2. 1194 * 1 implies ".", 2 implies ".." if second 1195 * char is also "." 1196 */ 1197 if (namlen == 1) 1198 continue; 1199 if (dp->e2d_name[1] == '.' && le32toh(dp->e2d_ino) == parentino) 1200 continue; 1201 return (0); 1202 } 1203 return (1); 1204 } 1205 1206 /* 1207 * Check if source directory is in the path of the target directory. 1208 * Target is supplied locked, source is unlocked. 1209 * The target is always vput before returning. 1210 */ 1211 int 1212 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred) 1213 { 1214 struct vnode *vp; 1215 int error, namlen; 1216 struct dirtemplate dirbuf; 1217 1218 vp = ITOV(target); 1219 if (target->i_number == source->i_number) { 1220 error = EEXIST; 1221 goto out; 1222 } 1223 if (target->i_number == EXT2_ROOTINO) { 1224 error = 0; 1225 goto out; 1226 } 1227 1228 for (;;) { 1229 if (vp->v_type != VDIR) { 1230 error = ENOTDIR; 1231 break; 1232 } 1233 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, 1234 sizeof(struct dirtemplate), (off_t)0, UIO_SYSSPACE, 1235 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, 1236 NULL); 1237 if (error != 0) 1238 break; 1239 namlen = dirbuf.dotdot_type; /* like ufs little-endian */ 1240 if (namlen != 2 || 1241 dirbuf.dotdot_name[0] != '.' || 1242 dirbuf.dotdot_name[1] != '.') { 1243 error = ENOTDIR; 1244 break; 1245 } 1246 if (le32toh(dirbuf.dotdot_ino) == source->i_number) { 1247 error = EINVAL; 1248 break; 1249 } 1250 if (le32toh(dirbuf.dotdot_ino) == EXT2_ROOTINO) 1251 break; 1252 vput(vp); 1253 if ((error = VFS_VGET(vp->v_mount, le32toh(dirbuf.dotdot_ino), 1254 LK_EXCLUSIVE, &vp)) != 0) { 1255 vp = NULL; 1256 break; 1257 } 1258 } 1259 1260 out: 1261 if (error == ENOTDIR) 1262 SDT_PROBE2(ext2fs, , lookup, trace, 1, 1263 "checkpath: .. not a directory"); 1264 if (vp != NULL) 1265 vput(vp); 1266 return (error); 1267 }
Cache object: 9f7f2582e9bc92744252df54ea09bf2f
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