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/sysctl.h> 57 #include <sys/uio.h> 58 59 #include <vfs/ufs/dir.h> 60 61 #include <vfs/ext2fs/fs.h> 62 #include <vfs/ext2fs/inode.h> 63 #include <vfs/ext2fs/ext2_mount.h> 64 #include <vfs/ext2fs/ext2fs.h> 65 #include <vfs/ext2fs/ext2_dinode.h> 66 #include <vfs/ext2fs/ext2_dir.h> 67 #include <vfs/ext2fs/ext2_extern.h> 68 #include <vfs/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, 0, "EXT2FS filesystem"); 83 84 /* 85 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) 86 while it is the native blocksize in ext2fs - thus, a #define 87 is no longer appropriate 88 */ 89 #undef DIRBLKSIZ 90 91 static u_char ext2_ft_to_dt[] = { 92 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ 93 DT_REG, /* EXT2_FT_REG_FILE */ 94 DT_DIR, /* EXT2_FT_DIR */ 95 DT_CHR, /* EXT2_FT_CHRDEV */ 96 DT_BLK, /* EXT2_FT_BLKDEV */ 97 DT_FIFO, /* EXT2_FT_FIFO */ 98 DT_SOCK, /* EXT2_FT_SOCK */ 99 DT_LNK, /* EXT2_FT_SYMLINK */ 100 }; 101 #define FTTODT(ft) \ 102 ((ft) < nitems(ext2_ft_to_dt) ? ext2_ft_to_dt[(ft)] : DT_UNKNOWN) 103 104 static u_char dt_to_ext2_ft[] = { 105 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ 106 EXT2_FT_FIFO, /* DT_FIFO */ 107 EXT2_FT_CHRDEV, /* DT_CHR */ 108 EXT2_FT_UNKNOWN, /* unused */ 109 EXT2_FT_DIR, /* DT_DIR */ 110 EXT2_FT_UNKNOWN, /* unused */ 111 EXT2_FT_BLKDEV, /* DT_BLK */ 112 EXT2_FT_UNKNOWN, /* unused */ 113 EXT2_FT_REG_FILE, /* DT_REG */ 114 EXT2_FT_UNKNOWN, /* unused */ 115 EXT2_FT_SYMLINK, /* DT_LNK */ 116 EXT2_FT_UNKNOWN, /* unused */ 117 EXT2_FT_SOCK, /* DT_SOCK */ 118 EXT2_FT_UNKNOWN, /* unused */ 119 EXT2_FT_UNKNOWN, /* DT_WHT */ 120 }; 121 #define DTTOFT(dt) \ 122 ((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN) 123 124 static int ext2_check_direntry(struct vnode *dp, 125 struct ext2fs_direct_2 *de, int entryoffsetinblock); 126 static int ext2_is_dot_entry(struct componentname *cnp); 127 static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, 128 struct componentname *cnp, ino_t *dd_ino); 129 130 static int 131 ext2_is_dot_entry(struct componentname *cnp) 132 { 133 if (cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' && 134 (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0')) 135 return (1); 136 return (0); 137 } 138 139 /* 140 * Vnode op for reading directories. 141 */ 142 int 143 ext2_readdir(struct vop_readdir_args *ap) 144 { 145 struct vnode *vp = ap->a_vp; 146 struct uio *uio = ap->a_uio; 147 struct buf *bp; 148 struct inode *ip; 149 struct ext2fs_direct_2 *dp, *edp; 150 u_long *cookies; 151 struct dirent dstdp; 152 off_t offset, startoffset; 153 size_t readcnt, skipcnt; 154 ssize_t startresid; 155 u_int ncookies; 156 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->e2fs_bsize; 157 int error; 158 159 if (uio->uio_offset < 0) 160 return (EINVAL); 161 ip = VTOI(vp); 162 if (ap->a_ncookies != NULL) { 163 if (uio->uio_resid < 0) 164 ncookies = 0; 165 else 166 ncookies = uio->uio_resid; 167 if (uio->uio_offset >= ip->i_size) 168 ncookies = 0; 169 else if (ip->i_size - uio->uio_offset < ncookies) 170 ncookies = ip->i_size - uio->uio_offset; 171 ncookies = ncookies / (offsetof(struct ext2fs_direct_2, 172 e2d_namlen) + 4) + 1; 173 cookies = malloc(ncookies * sizeof(*cookies), M_TEMP, M_WAITOK); 174 *ap->a_ncookies = ncookies; 175 *ap->a_cookies = cookies; 176 } else { 177 ncookies = 0; 178 cookies = NULL; 179 } 180 offset = startoffset = uio->uio_offset; 181 startresid = uio->uio_resid; 182 error = 0; 183 while (error == 0 && uio->uio_resid > 0 && 184 uio->uio_offset < ip->i_size) { 185 error = ext2_blkatoff(vp, uio->uio_offset, NULL, &bp); 186 if (error) 187 break; 188 if (bp->b_loffset + bp->b_bcount > ip->i_size) 189 readcnt = ip->i_size - bp->b_loffset; 190 else 191 readcnt = bp->b_bcount; 192 skipcnt = (size_t)(uio->uio_offset - bp->b_loffset) & 193 ~(size_t)(DIRBLKSIZ - 1); 194 offset = bp->b_loffset + skipcnt; 195 dp = (struct ext2fs_direct_2 *)&bp->b_data[skipcnt]; 196 edp = (struct ext2fs_direct_2 *)&bp->b_data[readcnt]; 197 while (error == 0 && uio->uio_resid > 0 && dp < edp) { 198 if (le16toh(dp->e2d_reclen) <= offsetof(struct ext2fs_direct_2, 199 e2d_namlen) || (caddr_t)dp + le16toh(dp->e2d_reclen) > 200 (caddr_t)edp) { 201 error = EIO; 202 break; 203 } 204 /*- 205 * "New" ext2fs directory entries differ in 3 ways 206 * from ufs on-disk ones: 207 * - the name is not necessarily NUL-terminated. 208 * - the file type field always exists and always 209 * follows the name length field. 210 * - the file type is encoded in a different way. 211 * 212 * "Old" ext2fs directory entries need no special 213 * conversions, since they are binary compatible 214 * with "new" entries having a file type of 0 (i.e., 215 * EXT2_FT_UNKNOWN). Splitting the old name length 216 * field didn't make a mess like it did in ufs, 217 * because ext2fs uses a machine-independent disk 218 * layout. 219 */ 220 dstdp.d_namlen = dp->e2d_namlen; 221 dstdp.d_type = FTTODT(dp->e2d_type); 222 if (offsetof(struct ext2fs_direct_2, e2d_namlen) + 223 dstdp.d_namlen > le16toh(dp->e2d_reclen)) { 224 error = EIO; 225 break; 226 } 227 if (offset < startoffset || le32toh(dp->e2d_ino) == 0) 228 goto nextentry; 229 dstdp.d_ino = le32toh(dp->e2d_ino); 230 bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen); 231 if (vop_write_dirent(&error, uio, dstdp.d_ino, 232 dstdp.d_type, dstdp.d_namlen, dstdp.d_name)) { 233 if (uio->uio_resid == startresid) 234 error = EINVAL; 235 else 236 error = EJUSTRETURN; 237 break; 238 } 239 if (error) 240 break; 241 if (cookies != NULL) { 242 KASSERT(ncookies > 0, 243 ("ext2_readdir: cookies buffer too small")); 244 *cookies = offset + le16toh(dp->e2d_reclen); 245 cookies++; 246 ncookies--; 247 } 248 nextentry: 249 offset += le16toh(dp->e2d_reclen); 250 dp = (struct ext2fs_direct_2 *)((caddr_t)dp + 251 le16toh(dp->e2d_reclen)); 252 } 253 bqrelse(bp); 254 uio->uio_offset = offset; 255 } 256 /* We need to correct uio_offset. */ 257 uio->uio_offset = offset; 258 if (error == EJUSTRETURN) 259 error = 0; 260 if (ap->a_ncookies != NULL) { 261 if (error == 0) { 262 ap->a_ncookies -= ncookies; 263 } else { 264 free(*ap->a_cookies, M_TEMP); 265 *ap->a_ncookies = 0; 266 *ap->a_cookies = NULL; 267 } 268 } 269 if (error == 0 && ap->a_eofflag) 270 *ap->a_eofflag = ip->i_size <= uio->uio_offset; 271 return (error); 272 } 273 274 /* 275 * Convert a component of a pathname into a pointer to a locked inode. 276 * This is a very central and rather complicated routine. 277 * If the file system is not maintained in a strict tree hierarchy, 278 * this can result in a deadlock situation (see comments in code below). 279 * 280 * The cnp->cn_nameiop argument is NAMEI_LOOKUP, NAMEI_CREATE, NAMEI_RENAME, or NAMEI_DELETE depending 281 * on whether the name is to be looked up, created, renamed, or deleted. 282 * When NAMEI_CREATE, NAMEI_RENAME, or NAMEI_DELETE is specified, information usable in 283 * creating, renaming, or deleting a directory entry may be calculated. 284 * If flag has LOCKPARENT or'ed into it and the target of the pathname 285 * exists, lookup returns both the target and its parent directory locked. 286 * When creating or renaming and LOCKPARENT is specified, the target may 287 * not be ".". When deleting and LOCKPARENT is specified, the target may 288 * be "."., but the caller must check to ensure it does an vrele and vput 289 * instead of two vputs. 290 * 291 * Overall outline of ext2_lookup: 292 * 293 * search for name in directory, to found or notfound 294 * notfound: 295 * if creating, return locked directory, leaving info on available slots 296 * else return error 297 * found: 298 * if at end of path and deleting, return information to allow delete 299 * if at end of path and rewriting (NAMEI_RENAME and LOCKPARENT), lock target 300 * inode and return info to allow rewrite 301 * if not at end, add name to cache; if at end and neither creating 302 * nor deleting, add name to cache 303 */ 304 int 305 ext2_lookup(struct vop_old_lookup_args *ap) 306 { 307 308 return (ext2_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL)); 309 } 310 311 static int 312 ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp, 313 ino_t *dd_ino) 314 { 315 struct inode *dp; /* inode for directory being searched */ 316 struct buf *bp; /* a buffer of directory entries */ 317 struct ext2fs_direct_2 *ep; /* the current directory entry */ 318 int entryoffsetinblock; /* offset of ep in bp's buffer */ 319 struct ext2fs_searchslot ss; 320 doff_t i_diroff; /* cached i_diroff value */ 321 doff_t i_offset; /* cached i_offset value */ 322 int numdirpasses; /* strategy for directory search */ 323 doff_t endsearch; /* offset to end directory search */ 324 doff_t prevoff; /* prev entry dp->i_offset */ 325 struct vnode *pdp; /* saved dp during symlink work */ 326 struct vnode *tdp; /* returned by VFS_VGET */ 327 doff_t enduseful; /* pointer past last used dir slot */ 328 u_long bmask; /* block offset mask */ 329 int error; 330 struct ucred *cred = cnp->cn_cred; 331 int flags = cnp->cn_flags; 332 int nameiop = cnp->cn_nameiop; 333 ino_t ino; 334 int entry_found = 0; 335 int lockparent; /* 1 => lockparent flag is set */ 336 int wantparent; /* 1 => wantparent or lockparent flag */ 337 338 int DIRBLKSIZ = VTOI(vdp)->i_e2fs->e2fs_bsize; 339 tdp = NULL; 340 341 if (vpp != NULL) 342 *vpp = NULL; 343 344 dp = VTOI(vdp); 345 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; 346 lockparent = flags & CNP_LOCKPARENT; 347 wantparent = flags & (CNP_LOCKPARENT | CNP_WANTPARENT); 348 349 bp = NULL; 350 ss.slotoffset = -1; 351 352 /* 353 * We now have a segment name to search for, and a directory to search. 354 * 355 * Suppress search for slots unless creating 356 * file and at end of pathname, in which case 357 * we watch for a place to put the new file in 358 * case it doesn't already exist. 359 */ 360 i_diroff = dp->i_diroff; 361 ss.slotstatus = FOUND; 362 ss.slotfreespace = ss.slotsize = ss.slotneeded = 0; 363 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME)) { 364 ss.slotstatus = NONE; 365 ss.slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); 366 /* 367 * was ss.slotneeded = (sizeof(struct direct) - MAXNAMLEN + 368 * cnp->cn_namelen + 3) &~ 3; 369 */ 370 } 371 /* 372 * Try to lookup dir entry using htree directory index. 373 * 374 * If we got an error or we want to find '.' or '..' entry, 375 * we will fall back to linear search. 376 */ 377 if (!ext2_is_dot_entry(cnp) && ext2_htree_has_idx(dp)) { 378 numdirpasses = 1; 379 entryoffsetinblock = 0; 380 switch (ext2_htree_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen, 381 &bp, &entryoffsetinblock, &i_offset, &prevoff, 382 &enduseful, &ss)) { 383 case 0: 384 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 385 (i_offset & bmask)); 386 goto foundentry; 387 case ENOENT: 388 i_offset = roundup2(dp->i_size, DIRBLKSIZ); 389 goto notfound; 390 default: 391 /* 392 * Something failed; just fallback to do a linear 393 * search. 394 */ 395 break; 396 } 397 } 398 399 /* 400 * If there is cached information on a previous search of 401 * this directory, pick up where we last left off. 402 * We cache only lookups as these are the most common 403 * and have the greatest payoff. Caching NAMEI_CREATE has little 404 * benefit as it usually must search the entire directory 405 * to determine that the entry does not exist. Caching the 406 * location of the last NAMEI_DELETE or NAMEI_RENAME has not reduced 407 * profiling time and hence has been removed in the interest 408 * of simplicity. 409 */ 410 if (nameiop != NAMEI_LOOKUP || i_diroff == 0 || 411 i_diroff > dp->i_size) { 412 entryoffsetinblock = 0; 413 i_offset = 0; 414 numdirpasses = 1; 415 } else { 416 i_offset = i_diroff; 417 if ((entryoffsetinblock = i_offset & bmask) && 418 (error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, 419 &bp))) 420 return (error); 421 numdirpasses = 2; 422 } 423 prevoff = i_offset; 424 endsearch = roundup2(dp->i_size, DIRBLKSIZ); 425 enduseful = 0; 426 427 searchloop: 428 while (i_offset < endsearch) { 429 /* 430 * If necessary, get the next directory block. 431 */ 432 if (bp != NULL) 433 brelse(bp); 434 error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, &bp); 435 if (error != 0) 436 return (error); 437 438 entryoffsetinblock = 0; 439 if (ss.slotstatus == NONE) { 440 ss.slotoffset = -1; 441 ss.slotfreespace = 0; 442 } 443 444 error = ext2_search_dirblock(dp, bp->b_data, &entry_found, 445 cnp->cn_nameptr, cnp->cn_namelen, 446 &entryoffsetinblock, &i_offset, &prevoff, 447 &enduseful, &ss); 448 if (error != 0) { 449 brelse(bp); 450 return (error); 451 } 452 if (entry_found) { 453 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 454 (entryoffsetinblock & bmask)); 455 foundentry: 456 ino = le32toh(ep->e2d_ino); 457 goto found; 458 } 459 } 460 notfound: 461 /* 462 * If we started in the middle of the directory and failed 463 * to find our target, we must check the beginning as well. 464 */ 465 if (numdirpasses == 2) { 466 numdirpasses--; 467 i_offset = 0; 468 endsearch = i_diroff; 469 goto searchloop; 470 } 471 if (bp != NULL) 472 brelse(bp); 473 /* 474 * If creating, and at end of pathname and current 475 * directory has not been removed, then can consider 476 * allowing file to be created. 477 */ 478 if ((nameiop == NAMEI_CREATE || nameiop == NAMEI_RENAME) && 479 dp->i_nlink != 0) { 480 /* 481 * Access for write is interpreted as allowing 482 * creation of files in the directory. 483 */ 484 if ((error = VOP_ACCESS(vdp, VWRITE, cred)) != 0) 485 return (error); 486 /* 487 * Return an indication of where the new directory 488 * entry should be put. If we didn't find a slot, 489 * then set dp->i_count to 0 indicating 490 * that the new slot belongs at the end of the 491 * directory. If we found a slot, then the new entry 492 * can be put in the range from dp->i_offset to 493 * dp->i_offset + dp->i_count. 494 */ 495 if (ss.slotstatus == NONE) { 496 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); 497 dp->i_count = 0; 498 enduseful = dp->i_offset; 499 } else { 500 dp->i_offset = ss.slotoffset; 501 dp->i_count = ss.slotsize; 502 if (enduseful < ss.slotoffset + ss.slotsize) 503 enduseful = ss.slotoffset + ss.slotsize; 504 } 505 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ); 506 /* 507 * We return with the directory locked, so that 508 * the parameters we set up above will still be 509 * valid if we actually decide to do a direnter(). 510 * We return ni_vp == NULL to indicate that the entry 511 * does not currently exist; we leave a pointer to 512 * the (locked) directory inode in ndp->ni_dvp. 513 * The pathname buffer is saved so that the name 514 * can be obtained later. 515 * 516 * NB - if the directory is unlocked, then this 517 * information cannot be used. 518 */ 519 if (!lockparent) 520 vn_unlock(vdp); 521 return (EJUSTRETURN); 522 } 523 return (ENOENT); 524 525 found: 526 if (dd_ino != NULL) 527 *dd_ino = ino; 528 /* 529 * Check that directory length properly reflects presence 530 * of this entry. 531 */ 532 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen) > 533 dp->i_size) { 534 ext2_dirbad(dp, i_offset, "i_size too small"); 535 dp->i_size = entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen); 536 dp->i_flag |= IN_CHANGE | IN_UPDATE; 537 } 538 brelse(bp); 539 540 /* 541 * Found component in pathname. 542 * If the final component of path name, save information 543 * in the cache as to where the entry was found. 544 */ 545 if (nameiop == NAMEI_LOOKUP) 546 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ); 547 /* 548 * If deleting, and at end of pathname, return 549 * parameters which can be used to remove file. 550 */ 551 if (nameiop == NAMEI_DELETE) { 552 if (lockparent) 553 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__); 554 /* 555 * Write access to directory required to delete files. 556 */ 557 if ((error = VOP_ACCESS(vdp, VWRITE, cred)) != 0) 558 return (error); 559 /* 560 * Return pointer to current entry in dp->i_offset, 561 * and distance past previous entry (if there 562 * is a previous entry in this block) in dp->i_count. 563 * Save directory inode pointer in ndp->ni_dvp for dirremove(). 564 * 565 * Technically we shouldn't be setting these in the 566 * WANTPARENT case (first lookup in rename()), but any 567 * lookups that will result in directory changes will 568 * overwrite these. 569 */ 570 dp->i_offset = i_offset; 571 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) 572 dp->i_count = 0; 573 else 574 dp->i_count = dp->i_offset - prevoff; 575 if (dd_ino != NULL) 576 return (0); 577 if (dp->i_number == ino) { 578 vref(vdp); 579 *vpp = vdp; 580 return (0); 581 } 582 if ((error = VFS_VGET(vdp->v_mount, NULL, ino, &tdp)) != 0) 583 return (error); 584 /* 585 * If directory is "sticky", then user must own 586 * the directory, or the file in it, else she 587 * may not delete it (unless she's root). This 588 * implements append-only directories. 589 */ 590 if ((dp->i_mode & ISVTX) && 591 cred->cr_uid != 0 && 592 cred->cr_uid != dp->i_uid && 593 VTOI(tdp)->i_uid != cred->cr_uid) { 594 vput(tdp); 595 return (EPERM); 596 } 597 *vpp = tdp; 598 if (!lockparent) 599 vn_unlock(vdp); 600 return (0); 601 } 602 603 /* 604 * If rewriting (NAMEI_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 == NAMEI_RENAME && wantparent) { 610 if ((error = VOP_ACCESS(vdp, VWRITE, cred)) != 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, NULL, ino, &tdp)) != 0) 622 return (error); 623 *vpp = tdp; 624 if (!lockparent) 625 vn_unlock(vdp); 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 & CNP_ISDOTDOT) { 652 vn_unlock(pdp); /* race to get the inode */ 653 error = VFS_VGET(vdp->v_mount, NULL, ino, &tdp); 654 if (error) { 655 vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY); 656 return (error); 657 } 658 if (lockparent) { 659 error = vn_lock(pdp, LK_EXCLUSIVE | LK_FAILRECLAIM); 660 if (error) { 661 vput(tdp); 662 return (error); 663 } 664 } 665 *vpp = tdp; 666 } else if (dp->i_number == ino) { 667 vref(vdp); /* we want ourself, ie "." */ 668 *vpp = vdp; 669 } else { 670 if ((error = VFS_VGET(vdp->v_mount, NULL, ino, &tdp)) != 0) 671 return (error); 672 if (!lockparent) { 673 vn_unlock(pdp); 674 cnp->cn_flags |= CNP_PDIRUNLOCK; 675 } 676 *vpp = tdp; 677 } 678 return (0); 679 } 680 681 int 682 ext2_search_dirblock(struct inode *ip, void *data, int *foundp, 683 const char *name, int namelen, int *entryoffsetinblockp, 684 doff_t *offp, doff_t *prevoffp, doff_t *endusefulp, 685 struct ext2fs_searchslot *ssp) 686 { 687 struct vnode *vdp; 688 struct ext2fs_direct_2 *ep, *top; 689 uint32_t bsize = ip->i_e2fs->e2fs_bsize; 690 int offset = *entryoffsetinblockp; 691 int namlen; 692 693 vdp = ITOV(ip); 694 695 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 696 top = (struct ext2fs_direct_2 *)((char *)data + bsize); 697 while (ep < top) { 698 if (ext2_check_direntry(vdp, ep, offset)) { 699 int i; 700 701 ext2_dirbad(ip, *offp, "mangled entry"); 702 i = bsize - (offset & (bsize - 1)); 703 *offp += i; 704 offset += i; 705 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 706 continue; 707 } 708 709 /* 710 * If an appropriate sized slot has not yet been found, 711 * check to see if one is available. Also accumulate space 712 * in the current block so that we can determine if 713 * compaction is viable. 714 */ 715 if (ssp->slotstatus != FOUND) { 716 int size = le16toh(ep->e2d_reclen); 717 718 if (ep->e2d_ino != 0) 719 size -= EXT2_DIR_REC_LEN(ep->e2d_namlen); 720 else if (ext2_is_dirent_tail(ip, ep)) 721 size -= sizeof(struct ext2fs_direct_tail); 722 if (size > 0) { 723 if (size >= ssp->slotneeded) { 724 ssp->slotstatus = FOUND; 725 ssp->slotoffset = *offp; 726 ssp->slotsize = le16toh(ep->e2d_reclen); 727 } else if (ssp->slotstatus == NONE) { 728 ssp->slotfreespace += size; 729 if (ssp->slotoffset == -1) 730 ssp->slotoffset = *offp; 731 if (ssp->slotfreespace >= ssp->slotneeded) { 732 ssp->slotstatus = COMPACT; 733 ssp->slotsize = *offp + 734 le16toh(ep->e2d_reclen) - 735 ssp->slotoffset; 736 } 737 } 738 } 739 } 740 /* 741 * Check for a name match. 742 */ 743 if (ep->e2d_ino != 0) { 744 namlen = ep->e2d_namlen; 745 if (namlen == namelen && 746 !bcmp(name, ep->e2d_name, (unsigned)namlen)) { 747 /* 748 * Save directory entry's inode number and 749 * reclen in ndp->ni_ufs area, and release 750 * directory buffer. 751 */ 752 *foundp = 1; 753 return (0); 754 } 755 } 756 *prevoffp = *offp; 757 *offp += le16toh(ep->e2d_reclen); 758 offset += le16toh(ep->e2d_reclen); 759 *entryoffsetinblockp = offset; 760 if (ep->e2d_ino != 0) 761 *endusefulp = *offp; 762 /* 763 * Get pointer to the next entry. 764 */ 765 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 766 } 767 768 return (0); 769 } 770 771 void 772 ext2_dirbad(struct inode *ip, doff_t offset, char *how) 773 { 774 struct mount *mp; 775 776 mp = ITOV(ip)->v_mount; 777 if ((mp->mnt_flag & MNT_RDONLY) == 0) 778 panic("ext2_dirbad: %s: bad dir ino %ju at offset %ld: %s\n", 779 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, 780 (long)offset, how); 781 else 782 SDT_PROBE4(ext2fs, , trace, ext2_dirbad_error, 783 mp->mnt_stat.f_mntonname, ip->i_number, offset, how); 784 } 785 786 /* 787 * Do consistency checking on a directory entry: 788 * record length must be multiple of 4 789 * entry must fit in rest of its DIRBLKSIZ block 790 * record must be large enough to contain entry 791 * name is not longer than MAXNAMLEN 792 * name must be as long as advertised, and null terminated 793 */ 794 static int 795 ext2_check_direntry(struct vnode *dp, struct ext2fs_direct_2 *de, 796 int entryoffsetinblock) 797 { 798 struct m_ext2fs *fs = VTOI(dp)->i_e2fs; 799 char *error_msg = NULL; 800 801 if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(1)) 802 error_msg = "rec_len is smaller than minimal"; 803 else if (le16toh(de->e2d_reclen) % 4 != 0) 804 error_msg = "rec_len % 4 != 0"; 805 else if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(de->e2d_namlen)) 806 error_msg = "reclen is too small for name_len"; 807 else if (entryoffsetinblock + le16toh(de->e2d_reclen)> fs->e2fs_bsize) 808 error_msg = "directory entry across blocks"; 809 else if (le32toh(de->e2d_ino) > fs->e2fs->e2fs_icount) 810 error_msg = "directory entry inode out of bounds"; 811 812 if (error_msg != NULL) { 813 SDT_PROBE5(ext2fs, , trace, ext2_dirbadentry_error, 814 error_msg, entryoffsetinblock, 815 le32toh(de->e2d_ino), le16toh(de->e2d_reclen), 816 de->e2d_namlen); 817 } 818 return (error_msg == NULL ? 0 : EINVAL); 819 } 820 821 /* 822 * Insert an entry into the fresh directory block. 823 * Initialize entry tail if the metadata_csum feature is turned on. 824 */ 825 static int 826 ext2_add_first_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry, 827 struct componentname *cnp) 828 { 829 struct inode *dp; 830 struct iovec aiov; 831 struct uio auio; 832 char* buf = NULL; 833 int dirblksize, error; 834 835 dp = VTOI(dvp); 836 dirblksize = dp->i_e2fs->e2fs_bsize; 837 838 if (dp->i_offset & (dirblksize - 1)) 839 panic("ext2_add_first_entry: bad directory offset"); 840 841 if (EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs, 842 EXT2F_ROCOMPAT_METADATA_CKSUM)) { 843 entry->e2d_reclen = htole16(dirblksize - 844 sizeof(struct ext2fs_direct_tail)); 845 buf = malloc(dirblksize, M_TEMP, M_WAITOK); 846 memcpy(buf, entry, EXT2_DIR_REC_LEN(entry->e2d_namlen)); 847 ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, dirblksize)); 848 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)buf); 849 850 auio.uio_offset = dp->i_offset; 851 auio.uio_resid = dirblksize; 852 aiov.iov_len = auio.uio_resid; 853 aiov.iov_base = (caddr_t)buf; 854 } else { 855 entry->e2d_reclen = htole16(dirblksize); 856 auio.uio_offset = dp->i_offset; 857 auio.uio_resid = EXT2_DIR_REC_LEN(entry->e2d_namlen); 858 aiov.iov_len = auio.uio_resid; 859 aiov.iov_base = (caddr_t)entry; 860 } 861 862 auio.uio_iov = &aiov; 863 auio.uio_iovcnt = 1; 864 auio.uio_rw = UIO_WRITE; 865 auio.uio_segflg = UIO_SYSSPACE; 866 auio.uio_td = (struct thread *)0; 867 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); 868 if (error) 869 goto out; 870 871 dp->i_size = roundup2(dp->i_size, dirblksize); 872 dp->i_flag |= IN_CHANGE; 873 874 out: 875 if (buf) 876 free(buf, M_TEMP); 877 return (error); 878 } 879 880 /* 881 * Write a directory entry after a call to namei, using the parameters 882 * that it left in nameidata. The argument ip is the inode which the new 883 * directory entry will refer to. Dvp is a pointer to the directory to 884 * be written, which was left locked by namei. Remaining parameters 885 * (dp->i_offset, dp->i_count) indicate how the space for the new 886 * entry is to be obtained. 887 */ 888 int 889 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp) 890 { 891 struct inode *dp; 892 struct ext2fs_direct_2 newdir; 893 //int DIRBLKSIZ = ip->i_e2fs->e2fs_bsize; 894 int error; 895 896 dp = VTOI(dvp); 897 newdir.e2d_ino = htole32(ip->i_number); 898 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 899 EXT2F_INCOMPAT_FTYPE)) { 900 newdir.e2d_namlen = cnp->cn_namelen; 901 newdir.e2d_type = DTTOFT(IFTODT(ip->i_mode)); 902 } else 903 newdir.e2d_namlen = htole16(cnp->cn_namelen); 904 905 bcopy(cnp->cn_nameptr, newdir.e2d_name, (unsigned)cnp->cn_namelen + 1); 906 907 /* 908 * XXX HTree dirents sometimes get lost (or not visible via readdir). 909 * This is reproducible by copying a directory with enough regular files 910 * (e.g. contrib/libarchive/libarchive) from somewhere to ext2 for 911 * several times until it reproduces. dumpe2fs shows same allocation as 912 * successful case. e2fsck says ext2 is clean with correct number of 913 * files. 914 * 915 * If that same image is mounted on Linux, some of the lost files are 916 * visible. E2fsck initially doesn't complain on Linux either, but 917 * after unmount, e2fsck starts to complain and files get recovered with 918 * a few sent to lost+found. 919 */ 920 #if 0 921 if (ext2_htree_has_idx(dp)) { 922 error = ext2_htree_add_entry(dvp, &newdir, cnp); 923 if (error) { 924 dp->i_flag &= ~IN_E3INDEX; 925 dp->i_flag |= IN_CHANGE | IN_UPDATE; 926 } 927 return (error); 928 } 929 930 if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) && 931 !ext2_htree_has_idx(dp)) { 932 if ((dp->i_size / DIRBLKSIZ) == 1 && 933 dp->i_offset == DIRBLKSIZ) { 934 /* 935 * Making indexed directory when one block is not 936 * enough to save all entries. 937 */ 938 return ext2_htree_create_index(dvp, cnp, &newdir); 939 } 940 } 941 #endif 942 /* 943 * If dp->i_count is 0, then namei could find no 944 * space in the directory. Here, dp->i_offset will 945 * be on a directory block boundary and we will write the 946 * new entry into a fresh block. 947 */ 948 if (dp->i_count == 0) 949 return ext2_add_first_entry(dvp, &newdir, cnp); 950 951 error = ext2_add_entry(dvp, &newdir); 952 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) 953 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, 954 cnp->cn_cred); 955 return (error); 956 } 957 958 /* 959 * Insert an entry into the directory block. 960 * Compact the contents. 961 */ 962 int 963 ext2_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry) 964 { 965 struct ext2fs_direct_2 *ep, *nep; 966 struct inode *dp; 967 struct buf *bp; 968 u_int dsize; 969 int error, loc, newentrysize, spacefree; 970 char *dirbuf; 971 972 dp = VTOI(dvp); 973 974 /* 975 * If dp->i_count is non-zero, then namei found space 976 * for the new entry in the range dp->i_offset to 977 * dp->i_offset + dp->i_count in the directory. 978 * To use this space, we may have to compact the entries located 979 * there, by copying them together towards the beginning of the 980 * block, leaving the free space in one usable chunk at the end. 981 */ 982 983 /* 984 * Increase size of directory if entry eats into new space. 985 * This should never push the size past a new multiple of 986 * DIRBLKSIZE. 987 * 988 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. 989 */ 990 if (dp->i_offset + dp->i_count > dp->i_size) 991 dp->i_size = dp->i_offset + dp->i_count; 992 /* 993 * Get the block containing the space for the new directory entry. 994 */ 995 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, 996 &bp)) != 0) 997 return (error); 998 /* 999 * Find space for the new entry. In the simple case, the entry at 1000 * offset base will have the space. If it does not, then namei 1001 * arranged that compacting the region dp->i_offset to 1002 * dp->i_offset + dp->i_count would yield the 1003 * space. 1004 */ 1005 newentrysize = EXT2_DIR_REC_LEN(entry->e2d_namlen); 1006 ep = (struct ext2fs_direct_2 *)dirbuf; 1007 dsize = EXT2_DIR_REC_LEN(ep->e2d_namlen); 1008 spacefree = le16toh(ep->e2d_reclen) - dsize; 1009 for (loc = le16toh(ep->e2d_reclen); loc < dp->i_count; ) { 1010 nep = (struct ext2fs_direct_2 *)(dirbuf + loc); 1011 if (le32toh(ep->e2d_ino)) { 1012 /* trim the existing slot */ 1013 ep->e2d_reclen = htole16(dsize); 1014 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1015 } else { 1016 /* overwrite; nothing there; header is ours */ 1017 spacefree += dsize; 1018 } 1019 dsize = EXT2_DIR_REC_LEN(nep->e2d_namlen); 1020 spacefree += le16toh(nep->e2d_reclen) - dsize; 1021 loc += le16toh(nep->e2d_reclen); 1022 bcopy((caddr_t)nep, (caddr_t)ep, dsize); 1023 } 1024 /* 1025 * Update the pointer fields in the previous entry (if any), 1026 * copy in the new entry, and write out the block. 1027 */ 1028 if (ep->e2d_ino == 0) { 1029 if (spacefree + dsize < newentrysize) 1030 panic("ext2_direnter: compact1"); 1031 entry->e2d_reclen = htole16(spacefree + dsize); 1032 } else { 1033 if (spacefree < newentrysize) 1034 panic("ext2_direnter: compact2"); 1035 entry->e2d_reclen = htole16(spacefree); 1036 ep->e2d_reclen = htole16(dsize); 1037 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1038 } 1039 bcopy((caddr_t)entry, (caddr_t)ep, (u_int)newentrysize); 1040 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1041 if (DOINGASYNC(dvp)) { 1042 bdwrite(bp); 1043 error = 0; 1044 } else { 1045 error = bwrite(bp); 1046 } 1047 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1048 return (error); 1049 } 1050 1051 /* 1052 * Remove a directory entry after a call to namei, using 1053 * the parameters which it left in nameidata. The entry 1054 * dp->i_offset contains the offset into the directory of the 1055 * entry to be eliminated. The dp->i_count field contains the 1056 * size of the previous record in the directory. If this 1057 * is 0, the first entry is being deleted, so we need only 1058 * zero the inode number to mark the entry as free. If the 1059 * entry is not the first in the directory, we must reclaim 1060 * the space of the now empty record by adding the record size 1061 * to the size of the previous entry. 1062 */ 1063 int 1064 ext2_dirremove(struct vnode *dvp, struct componentname *cnp) 1065 { 1066 struct inode *dp; 1067 struct ext2fs_direct_2 *ep, *rep; 1068 struct buf *bp; 1069 int error; 1070 1071 dp = VTOI(dvp); 1072 if (dp->i_count == 0) { 1073 /* 1074 * First entry in block: set d_ino to zero. 1075 */ 1076 if ((error = 1077 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, 1078 &bp)) != 0) 1079 return (error); 1080 ep->e2d_ino = 0; 1081 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1082 error = bwrite(bp); 1083 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1084 return (error); 1085 } 1086 /* 1087 * Collapse new free space into previous entry. 1088 */ 1089 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), 1090 (char **)&ep, &bp)) != 0) 1091 return (error); 1092 1093 /* Set 'rep' to the entry being removed. */ 1094 if (dp->i_count == 0) 1095 rep = ep; 1096 else 1097 rep = (struct ext2fs_direct_2 *)((char *)ep + 1098 le16toh(ep->e2d_reclen)); 1099 ep->e2d_reclen += rep->e2d_reclen; 1100 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1101 if (DOINGASYNC(dvp) && dp->i_count != 0) 1102 bdwrite(bp); 1103 else 1104 error = bwrite(bp); 1105 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1106 return (error); 1107 } 1108 1109 /* 1110 * Rewrite an existing directory entry to point at the inode 1111 * supplied. The parameters describing the directory entry are 1112 * set up by a call to namei. 1113 */ 1114 int 1115 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp) 1116 { 1117 struct buf *bp; 1118 struct ext2fs_direct_2 *ep; 1119 struct vnode *vdp = ITOV(dp); 1120 int error; 1121 1122 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, 1123 &bp)) != 0) 1124 return (error); 1125 ep->e2d_ino = htole32(ip->i_number); 1126 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 1127 EXT2F_INCOMPAT_FTYPE)) 1128 ep->e2d_type = DTTOFT(IFTODT(ip->i_mode)); 1129 else 1130 ep->e2d_type = EXT2_FT_UNKNOWN; 1131 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1132 error = bwrite(bp); 1133 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1134 return (error); 1135 } 1136 1137 /* 1138 * Check if a directory is empty or not. 1139 * Inode supplied must be locked. 1140 * 1141 * Using a struct dirtemplate here is not precisely 1142 * what we want, but better than using a struct direct. 1143 * 1144 * NB: does not handle corrupted directories. 1145 */ 1146 int 1147 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) 1148 { 1149 off_t off; 1150 struct dirtemplate dbuf; 1151 struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf; 1152 int error, count, namlen; 1153 #define MINDIRSIZ (sizeof(struct dirtemplate) / 2) 1154 1155 for (off = 0; off < ip->i_size; off += le16toh(dp->e2d_reclen)) { 1156 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, 1157 off, UIO_SYSSPACE, IO_NODELOCKED, cred, &count); 1158 /* 1159 * Since we read MINDIRSIZ, residual must 1160 * be 0 unless we're at end of file. 1161 */ 1162 if (error || count != 0) 1163 return (0); 1164 /* avoid infinite loops */ 1165 if (dp->e2d_reclen == 0) 1166 return (0); 1167 /* skip empty entries */ 1168 if (dp->e2d_ino == 0) 1169 continue; 1170 /* accept only "." and ".." */ 1171 namlen = dp->e2d_namlen; 1172 if (namlen > 2) 1173 return (0); 1174 if (dp->e2d_name[0] != '.') 1175 return (0); 1176 /* 1177 * At this point namlen must be 1 or 2. 1178 * 1 implies ".", 2 implies ".." if second 1179 * char is also "." 1180 */ 1181 if (namlen == 1) 1182 continue; 1183 if (dp->e2d_name[1] == '.' && le32toh(dp->e2d_ino) == parentino) 1184 continue; 1185 return (0); 1186 } 1187 return (1); 1188 } 1189 1190 /* 1191 * Check if source directory is in the path of the target directory. 1192 * Target is supplied locked, source is unlocked. 1193 * The target is always vput before returning. 1194 */ 1195 int 1196 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred) 1197 { 1198 struct vnode *vp; 1199 int error, namlen; 1200 struct dirtemplate dirbuf; 1201 1202 vp = ITOV(target); 1203 if (target->i_number == source->i_number) { 1204 error = EEXIST; 1205 goto out; 1206 } 1207 if (target->i_number == EXT2_ROOTINO) { 1208 error = 0; 1209 goto out; 1210 } 1211 1212 for (;;) { 1213 if (vp->v_type != VDIR) { 1214 error = ENOTDIR; 1215 break; 1216 } 1217 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, 1218 sizeof(struct dirtemplate), (off_t)0, 1219 UIO_SYSSPACE, IO_NODELOCKED, cred, NULL); 1220 if (error != 0) 1221 break; 1222 namlen = dirbuf.dotdot_type; /* like ufs little-endian */ 1223 if (namlen != 2 || 1224 dirbuf.dotdot_name[0] != '.' || 1225 dirbuf.dotdot_name[1] != '.') { 1226 error = ENOTDIR; 1227 break; 1228 } 1229 if (le32toh(dirbuf.dotdot_ino) == source->i_number) { 1230 error = EINVAL; 1231 break; 1232 } 1233 if (le32toh(dirbuf.dotdot_ino) == EXT2_ROOTINO) 1234 break; 1235 vput(vp); 1236 if ((error = VFS_VGET(vp->v_mount, NULL, 1237 le32toh(dirbuf.dotdot_ino), &vp)) != 0) { 1238 vp = NULL; 1239 break; 1240 } 1241 } 1242 1243 out: 1244 if (error == ENOTDIR) 1245 SDT_PROBE2(ext2fs, , lookup, trace, 1, 1246 "checkpath: .. not a directory"); 1247 if (vp != NULL) 1248 vput(vp); 1249 return (error); 1250 } 1251