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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: head/sys/fs/ext2fs/ext2_lookup.c 346267 2019-04-16 11:20:10Z fsu $ 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 #ifdef INVARIANTS 83 static int dirchk = 1; 84 #else 85 static int dirchk = 0; 86 #endif 87 88 static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD, 0, "EXT2FS filesystem"); 89 SYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, ""); 90 91 /* 92 DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512) 93 while it is the native blocksize in ext2fs - thus, a #define 94 is no longer appropriate 95 */ 96 #undef DIRBLKSIZ 97 98 static u_char ext2_ft_to_dt[] = { 99 DT_UNKNOWN, /* EXT2_FT_UNKNOWN */ 100 DT_REG, /* EXT2_FT_REG_FILE */ 101 DT_DIR, /* EXT2_FT_DIR */ 102 DT_CHR, /* EXT2_FT_CHRDEV */ 103 DT_BLK, /* EXT2_FT_BLKDEV */ 104 DT_FIFO, /* EXT2_FT_FIFO */ 105 DT_SOCK, /* EXT2_FT_SOCK */ 106 DT_LNK, /* EXT2_FT_SYMLINK */ 107 }; 108 #define FTTODT(ft) \ 109 ((ft) < nitems(ext2_ft_to_dt) ? ext2_ft_to_dt[(ft)] : DT_UNKNOWN) 110 111 static u_char dt_to_ext2_ft[] = { 112 EXT2_FT_UNKNOWN, /* DT_UNKNOWN */ 113 EXT2_FT_FIFO, /* DT_FIFO */ 114 EXT2_FT_CHRDEV, /* DT_CHR */ 115 EXT2_FT_UNKNOWN, /* unused */ 116 EXT2_FT_DIR, /* DT_DIR */ 117 EXT2_FT_UNKNOWN, /* unused */ 118 EXT2_FT_BLKDEV, /* DT_BLK */ 119 EXT2_FT_UNKNOWN, /* unused */ 120 EXT2_FT_REG_FILE, /* DT_REG */ 121 EXT2_FT_UNKNOWN, /* unused */ 122 EXT2_FT_SYMLINK, /* DT_LNK */ 123 EXT2_FT_UNKNOWN, /* unused */ 124 EXT2_FT_SOCK, /* DT_SOCK */ 125 EXT2_FT_UNKNOWN, /* unused */ 126 EXT2_FT_UNKNOWN, /* DT_WHT */ 127 }; 128 #define DTTOFT(dt) \ 129 ((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN) 130 131 static int ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2 *de, 132 int entryoffsetinblock); 133 static int ext2_is_dot_entry(struct componentname *cnp); 134 static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, 135 struct componentname *cnp, ino_t *dd_ino); 136 137 static int 138 ext2_is_dot_entry(struct componentname *cnp) 139 { 140 if (cnp->cn_namelen <= 2 && cnp->cn_nameptr[0] == '.' && 141 (cnp->cn_nameptr[1] == '.' || cnp->cn_nameptr[1] == '\0')) 142 return (1); 143 return (0); 144 } 145 146 /* 147 * Vnode op for reading directories. 148 */ 149 int 150 ext2_readdir(struct vop_readdir_args *ap) 151 { 152 struct vnode *vp = ap->a_vp; 153 struct uio *uio = ap->a_uio; 154 struct buf *bp; 155 struct inode *ip; 156 struct ext2fs_direct_2 *dp, *edp; 157 u_long *cookies; 158 struct dirent dstdp; 159 off_t offset, startoffset; 160 size_t readcnt, skipcnt; 161 ssize_t startresid; 162 u_int ncookies; 163 int DIRBLKSIZ = VTOI(ap->a_vp)->i_e2fs->e2fs_bsize; 164 int error; 165 166 if (uio->uio_offset < 0) 167 return (EINVAL); 168 ip = VTOI(vp); 169 if (ap->a_ncookies != NULL) { 170 if (uio->uio_resid < 0) 171 ncookies = 0; 172 else 173 ncookies = uio->uio_resid; 174 if (uio->uio_offset >= ip->i_size) 175 ncookies = 0; 176 else if (ip->i_size - uio->uio_offset < ncookies) 177 ncookies = ip->i_size - uio->uio_offset; 178 ncookies = ncookies / (offsetof(struct ext2fs_direct_2, 179 e2d_namlen) + 4) + 1; 180 cookies = malloc(ncookies * sizeof(*cookies), M_TEMP, M_WAITOK); 181 *ap->a_ncookies = ncookies; 182 *ap->a_cookies = cookies; 183 } else { 184 ncookies = 0; 185 cookies = NULL; 186 } 187 offset = startoffset = uio->uio_offset; 188 startresid = uio->uio_resid; 189 error = 0; 190 while (error == 0 && uio->uio_resid > 0 && 191 uio->uio_offset < ip->i_size) { 192 error = ext2_blkatoff(vp, uio->uio_offset, NULL, &bp); 193 if (error) 194 break; 195 if (bp->b_offset + bp->b_bcount > ip->i_size) 196 readcnt = ip->i_size - bp->b_offset; 197 else 198 readcnt = bp->b_bcount; 199 skipcnt = (size_t)(uio->uio_offset - bp->b_offset) & 200 ~(size_t)(DIRBLKSIZ - 1); 201 offset = bp->b_offset + skipcnt; 202 dp = (struct ext2fs_direct_2 *)&bp->b_data[skipcnt]; 203 edp = (struct ext2fs_direct_2 *)&bp->b_data[readcnt]; 204 while (error == 0 && uio->uio_resid > 0 && dp < edp) { 205 if (dp->e2d_reclen <= offsetof(struct ext2fs_direct_2, 206 e2d_namlen) || (caddr_t)dp + dp->e2d_reclen > 207 (caddr_t)edp) { 208 error = EIO; 209 break; 210 } 211 /*- 212 * "New" ext2fs directory entries differ in 3 ways 213 * from ufs on-disk ones: 214 * - the name is not necessarily NUL-terminated. 215 * - the file type field always exists and always 216 * follows the name length field. 217 * - the file type is encoded in a different way. 218 * 219 * "Old" ext2fs directory entries need no special 220 * conversions, since they are binary compatible 221 * with "new" entries having a file type of 0 (i.e., 222 * EXT2_FT_UNKNOWN). Splitting the old name length 223 * field didn't make a mess like it did in ufs, 224 * because ext2fs uses a machine-independent disk 225 * layout. 226 */ 227 dstdp.d_namlen = dp->e2d_namlen; 228 dstdp.d_type = FTTODT(dp->e2d_type); 229 if (offsetof(struct ext2fs_direct_2, e2d_namlen) + 230 dstdp.d_namlen > dp->e2d_reclen) { 231 error = EIO; 232 break; 233 } 234 if (offset < startoffset || dp->e2d_ino == 0) 235 goto nextentry; 236 dstdp.d_fileno = dp->e2d_ino; 237 dstdp.d_reclen = GENERIC_DIRSIZ(&dstdp); 238 bcopy(dp->e2d_name, dstdp.d_name, dstdp.d_namlen); 239 /* NOTE: d_off is the offset of the *next* entry. */ 240 dstdp.d_off = offset + dp->e2d_reclen; 241 dirent_terminate(&dstdp); 242 if (dstdp.d_reclen > uio->uio_resid) { 243 if (uio->uio_resid == startresid) 244 error = EINVAL; 245 else 246 error = EJUSTRETURN; 247 break; 248 } 249 /* Advance dp. */ 250 error = uiomove((caddr_t)&dstdp, dstdp.d_reclen, uio); 251 if (error) 252 break; 253 if (cookies != NULL) { 254 KASSERT(ncookies > 0, 255 ("ext2_readdir: cookies buffer too small")); 256 *cookies = offset + dp->e2d_reclen; 257 cookies++; 258 ncookies--; 259 } 260 nextentry: 261 offset += dp->e2d_reclen; 262 dp = (struct ext2fs_direct_2 *)((caddr_t)dp + 263 dp->e2d_reclen); 264 } 265 bqrelse(bp); 266 uio->uio_offset = offset; 267 } 268 /* We need to correct uio_offset. */ 269 uio->uio_offset = offset; 270 if (error == EJUSTRETURN) 271 error = 0; 272 if (ap->a_ncookies != NULL) { 273 if (error == 0) { 274 ap->a_ncookies -= ncookies; 275 } else { 276 free(*ap->a_cookies, M_TEMP); 277 *ap->a_ncookies = 0; 278 *ap->a_cookies = NULL; 279 } 280 } 281 if (error == 0 && ap->a_eofflag) 282 *ap->a_eofflag = ip->i_size <= uio->uio_offset; 283 return (error); 284 } 285 286 /* 287 * Convert a component of a pathname into a pointer to a locked inode. 288 * This is a very central and rather complicated routine. 289 * If the file system is not maintained in a strict tree hierarchy, 290 * this can result in a deadlock situation (see comments in code below). 291 * 292 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending 293 * on whether the name is to be looked up, created, renamed, or deleted. 294 * When CREATE, RENAME, or DELETE is specified, information usable in 295 * creating, renaming, or deleting a directory entry may be calculated. 296 * If flag has LOCKPARENT or'ed into it and the target of the pathname 297 * exists, lookup returns both the target and its parent directory locked. 298 * When creating or renaming and LOCKPARENT is specified, the target may 299 * not be ".". When deleting and LOCKPARENT is specified, the target may 300 * be "."., but the caller must check to ensure it does an vrele and vput 301 * instead of two vputs. 302 * 303 * Overall outline of ext2_lookup: 304 * 305 * search for name in directory, to found or notfound 306 * notfound: 307 * if creating, return locked directory, leaving info on available slots 308 * else return error 309 * found: 310 * if at end of path and deleting, return information to allow delete 311 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target 312 * inode and return info to allow rewrite 313 * if not at end, add name to cache; if at end and neither creating 314 * nor deleting, add name to cache 315 */ 316 int 317 ext2_lookup(struct vop_cachedlookup_args *ap) 318 { 319 320 return (ext2_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL)); 321 } 322 323 static int 324 ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp, 325 ino_t *dd_ino) 326 { 327 struct inode *dp; /* inode for directory being searched */ 328 struct buf *bp; /* a buffer of directory entries */ 329 struct ext2fs_direct_2 *ep; /* the current directory entry */ 330 int entryoffsetinblock; /* offset of ep in bp's buffer */ 331 struct ext2fs_searchslot ss; 332 doff_t i_diroff; /* cached i_diroff value */ 333 doff_t i_offset; /* cached i_offset value */ 334 int numdirpasses; /* strategy for directory search */ 335 doff_t endsearch; /* offset to end directory search */ 336 doff_t prevoff; /* prev entry dp->i_offset */ 337 struct vnode *pdp; /* saved dp during symlink work */ 338 struct vnode *tdp; /* returned by VFS_VGET */ 339 doff_t enduseful; /* pointer past last used dir slot */ 340 u_long bmask; /* block offset mask */ 341 int error; 342 struct ucred *cred = cnp->cn_cred; 343 int flags = cnp->cn_flags; 344 int nameiop = cnp->cn_nameiop; 345 ino_t ino, ino1; 346 int ltype; 347 int entry_found = 0; 348 349 int DIRBLKSIZ = VTOI(vdp)->i_e2fs->e2fs_bsize; 350 351 if (vpp != NULL) 352 *vpp = NULL; 353 354 dp = VTOI(vdp); 355 bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1; 356 restart: 357 bp = NULL; 358 ss.slotoffset = -1; 359 360 /* 361 * We now have a segment name to search for, and a directory to search. 362 * 363 * Suppress search for slots unless creating 364 * file and at end of pathname, in which case 365 * we watch for a place to put the new file in 366 * case it doesn't already exist. 367 */ 368 i_diroff = dp->i_diroff; 369 ss.slotstatus = FOUND; 370 ss.slotfreespace = ss.slotsize = ss.slotneeded = 0; 371 if ((nameiop == CREATE || nameiop == RENAME) && 372 (flags & ISLASTCN)) { 373 ss.slotstatus = NONE; 374 ss.slotneeded = EXT2_DIR_REC_LEN(cnp->cn_namelen); 375 /* 376 * was ss.slotneeded = (sizeof(struct direct) - MAXNAMLEN + 377 * cnp->cn_namelen + 3) &~ 3; 378 */ 379 } 380 /* 381 * Try to lookup dir entry using htree directory index. 382 * 383 * If we got an error or we want to find '.' or '..' entry, 384 * we will fall back to linear search. 385 */ 386 if (!ext2_is_dot_entry(cnp) && ext2_htree_has_idx(dp)) { 387 numdirpasses = 1; 388 entryoffsetinblock = 0; 389 switch (ext2_htree_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen, 390 &bp, &entryoffsetinblock, &i_offset, &prevoff, 391 &enduseful, &ss)) { 392 case 0: 393 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 394 (i_offset & bmask)); 395 goto foundentry; 396 case ENOENT: 397 i_offset = roundup2(dp->i_size, DIRBLKSIZ); 398 goto notfound; 399 default: 400 /* 401 * Something failed; just fallback to do a linear 402 * search. 403 */ 404 break; 405 } 406 } 407 408 /* 409 * If there is cached information on a previous search of 410 * this directory, pick up where we last left off. 411 * We cache only lookups as these are the most common 412 * and have the greatest payoff. Caching CREATE has little 413 * benefit as it usually must search the entire directory 414 * to determine that the entry does not exist. Caching the 415 * location of the last DELETE or RENAME has not reduced 416 * profiling time and hence has been removed in the interest 417 * of simplicity. 418 */ 419 if (nameiop != LOOKUP || i_diroff == 0 || 420 i_diroff > dp->i_size) { 421 entryoffsetinblock = 0; 422 i_offset = 0; 423 numdirpasses = 1; 424 } else { 425 i_offset = i_diroff; 426 if ((entryoffsetinblock = i_offset & bmask) && 427 (error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, 428 &bp))) 429 return (error); 430 numdirpasses = 2; 431 nchstats.ncs_2passes++; 432 } 433 prevoff = i_offset; 434 endsearch = roundup2(dp->i_size, DIRBLKSIZ); 435 enduseful = 0; 436 437 searchloop: 438 while (i_offset < endsearch) { 439 /* 440 * If necessary, get the next directory block. 441 */ 442 if (bp != NULL) 443 brelse(bp); 444 error = ext2_blkatoff(vdp, (off_t)i_offset, NULL, &bp); 445 if (error != 0) 446 return (error); 447 448 entryoffsetinblock = 0; 449 if (ss.slotstatus == NONE) { 450 ss.slotoffset = -1; 451 ss.slotfreespace = 0; 452 } 453 454 error = ext2_search_dirblock(dp, bp->b_data, &entry_found, 455 cnp->cn_nameptr, cnp->cn_namelen, 456 &entryoffsetinblock, &i_offset, &prevoff, 457 &enduseful, &ss); 458 if (error != 0) { 459 brelse(bp); 460 return (error); 461 } 462 if (entry_found) { 463 ep = (struct ext2fs_direct_2 *)((char *)bp->b_data + 464 (entryoffsetinblock & bmask)); 465 foundentry: 466 ino = ep->e2d_ino; 467 goto found; 468 } 469 } 470 notfound: 471 /* 472 * If we started in the middle of the directory and failed 473 * to find our target, we must check the beginning as well. 474 */ 475 if (numdirpasses == 2) { 476 numdirpasses--; 477 i_offset = 0; 478 endsearch = i_diroff; 479 goto searchloop; 480 } 481 if (bp != NULL) 482 brelse(bp); 483 /* 484 * If creating, and at end of pathname and current 485 * directory has not been removed, then can consider 486 * allowing file to be created. 487 */ 488 if ((nameiop == CREATE || nameiop == RENAME) && 489 (flags & ISLASTCN) && dp->i_nlink != 0) { 490 /* 491 * Access for write is interpreted as allowing 492 * creation of files in the directory. 493 */ 494 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 495 return (error); 496 /* 497 * Return an indication of where the new directory 498 * entry should be put. If we didn't find a slot, 499 * then set dp->i_count to 0 indicating 500 * that the new slot belongs at the end of the 501 * directory. If we found a slot, then the new entry 502 * can be put in the range from dp->i_offset to 503 * dp->i_offset + dp->i_count. 504 */ 505 if (ss.slotstatus == NONE) { 506 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ); 507 dp->i_count = 0; 508 enduseful = dp->i_offset; 509 } else { 510 dp->i_offset = ss.slotoffset; 511 dp->i_count = ss.slotsize; 512 if (enduseful < ss.slotoffset + ss.slotsize) 513 enduseful = ss.slotoffset + ss.slotsize; 514 } 515 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ); 516 /* 517 * We return with the directory locked, so that 518 * the parameters we set up above will still be 519 * valid if we actually decide to do a direnter(). 520 * We return ni_vp == NULL to indicate that the entry 521 * does not currently exist; we leave a pointer to 522 * the (locked) directory inode in ndp->ni_dvp. 523 * The pathname buffer is saved so that the name 524 * can be obtained later. 525 * 526 * NB - if the directory is unlocked, then this 527 * information cannot be used. 528 */ 529 cnp->cn_flags |= SAVENAME; 530 return (EJUSTRETURN); 531 } 532 /* 533 * Insert name into cache (as non-existent) if appropriate. 534 */ 535 if ((cnp->cn_flags & MAKEENTRY) != 0) 536 cache_enter(vdp, NULL, cnp); 537 return (ENOENT); 538 539 found: 540 if (dd_ino != NULL) 541 *dd_ino = ino; 542 if (numdirpasses == 2) 543 nchstats.ncs_pass2++; 544 /* 545 * Check that directory length properly reflects presence 546 * of this entry. 547 */ 548 if (entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen) 549 > dp->i_size) { 550 ext2_dirbad(dp, i_offset, "i_size too small"); 551 dp->i_size = entryoffsetinblock + EXT2_DIR_REC_LEN(ep->e2d_namlen); 552 dp->i_flag |= IN_CHANGE | IN_UPDATE; 553 } 554 brelse(bp); 555 556 /* 557 * Found component in pathname. 558 * If the final component of path name, save information 559 * in the cache as to where the entry was found. 560 */ 561 if ((flags & ISLASTCN) && nameiop == LOOKUP) 562 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ); 563 /* 564 * If deleting, and at end of pathname, return 565 * parameters which can be used to remove file. 566 */ 567 if (nameiop == DELETE && (flags & ISLASTCN)) { 568 if (flags & LOCKPARENT) 569 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__); 570 /* 571 * Write access to directory required to delete files. 572 */ 573 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 574 return (error); 575 /* 576 * Return pointer to current entry in dp->i_offset, 577 * and distance past previous entry (if there 578 * is a previous entry in this block) in dp->i_count. 579 * Save directory inode pointer in ndp->ni_dvp for dirremove(). 580 * 581 * Technically we shouldn't be setting these in the 582 * WANTPARENT case (first lookup in rename()), but any 583 * lookups that will result in directory changes will 584 * overwrite these. 585 */ 586 dp->i_offset = i_offset; 587 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0) 588 dp->i_count = 0; 589 else 590 dp->i_count = dp->i_offset - prevoff; 591 if (dd_ino != NULL) 592 return (0); 593 if (dp->i_number == ino) { 594 VREF(vdp); 595 *vpp = vdp; 596 return (0); 597 } 598 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, 599 &tdp)) != 0) 600 return (error); 601 /* 602 * If directory is "sticky", then user must own 603 * the directory, or the file in it, else she 604 * may not delete it (unless she's root). This 605 * implements append-only directories. 606 */ 607 if ((dp->i_mode & ISVTX) && 608 cred->cr_uid != 0 && 609 cred->cr_uid != dp->i_uid && 610 VTOI(tdp)->i_uid != cred->cr_uid) { 611 vput(tdp); 612 return (EPERM); 613 } 614 *vpp = tdp; 615 return (0); 616 } 617 618 /* 619 * If rewriting (RENAME), return the inode and the 620 * information required to rewrite the present directory 621 * Must get inode of directory entry to verify it's a 622 * regular file, or empty directory. 623 */ 624 if (nameiop == RENAME && (flags & ISLASTCN)) { 625 if ((error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread)) != 0) 626 return (error); 627 /* 628 * Careful about locking second inode. 629 * This can only occur if the target is ".". 630 */ 631 dp->i_offset = i_offset; 632 if (dp->i_number == ino) 633 return (EISDIR); 634 if (dd_ino != NULL) 635 return (0); 636 if ((error = VFS_VGET(vdp->v_mount, ino, LK_EXCLUSIVE, 637 &tdp)) != 0) 638 return (error); 639 *vpp = tdp; 640 cnp->cn_flags |= SAVENAME; 641 return (0); 642 } 643 if (dd_ino != NULL) 644 return (0); 645 646 /* 647 * Step through the translation in the name. We do not `vput' the 648 * directory because we may need it again if a symbolic link 649 * is relative to the current directory. Instead we save it 650 * unlocked as "pdp". We must get the target inode before unlocking 651 * the directory to insure that the inode will not be removed 652 * before we get it. We prevent deadlock by always fetching 653 * inodes from the root, moving down the directory tree. Thus 654 * when following backward pointers ".." we must unlock the 655 * parent directory before getting the requested directory. 656 * There is a potential race condition here if both the current 657 * and parent directories are removed before the VFS_VGET for the 658 * inode associated with ".." returns. We hope that this occurs 659 * infrequently since we cannot avoid this race condition without 660 * implementing a sophisticated deadlock detection algorithm. 661 * Note also that this simple deadlock detection scheme will not 662 * work if the file system has any hard links other than ".." 663 * that point backwards in the directory structure. 664 */ 665 pdp = vdp; 666 if (flags & ISDOTDOT) { 667 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp); 668 if (pdp->v_iflag & VI_DOOMED) { 669 if (error == 0) 670 vput(tdp); 671 error = ENOENT; 672 } 673 if (error) 674 return (error); 675 /* 676 * Recheck that ".." entry in the vdp directory points 677 * to the inode we looked up before vdp lock was 678 * dropped. 679 */ 680 error = ext2_lookup_ino(pdp, NULL, cnp, &ino1); 681 if (error) { 682 vput(tdp); 683 return (error); 684 } 685 if (ino1 != ino) { 686 vput(tdp); 687 goto restart; 688 } 689 *vpp = tdp; 690 } else if (dp->i_number == ino) { 691 VREF(vdp); /* we want ourself, ie "." */ 692 /* 693 * When we lookup "." we still can be asked to lock it 694 * differently. 695 */ 696 ltype = cnp->cn_lkflags & LK_TYPE_MASK; 697 if (ltype != VOP_ISLOCKED(vdp)) { 698 if (ltype == LK_EXCLUSIVE) 699 vn_lock(vdp, LK_UPGRADE | LK_RETRY); 700 else /* if (ltype == LK_SHARED) */ 701 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY); 702 } 703 *vpp = vdp; 704 } else { 705 if ((error = VFS_VGET(vdp->v_mount, ino, cnp->cn_lkflags, 706 &tdp)) != 0) 707 return (error); 708 *vpp = tdp; 709 } 710 711 /* 712 * Insert name into cache if appropriate. 713 */ 714 if (cnp->cn_flags & MAKEENTRY) 715 cache_enter(vdp, *vpp, cnp); 716 return (0); 717 } 718 719 int 720 ext2_search_dirblock(struct inode *ip, void *data, int *foundp, 721 const char *name, int namelen, int *entryoffsetinblockp, 722 doff_t *offp, doff_t *prevoffp, doff_t *endusefulp, 723 struct ext2fs_searchslot *ssp) 724 { 725 struct vnode *vdp; 726 struct ext2fs_direct_2 *ep, *top; 727 uint32_t bsize = ip->i_e2fs->e2fs_bsize; 728 int offset = *entryoffsetinblockp; 729 int namlen; 730 731 vdp = ITOV(ip); 732 733 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 734 top = (struct ext2fs_direct_2 *)((char *)data + bsize); 735 while (ep < top) { 736 /* 737 * Full validation checks are slow, so we only check 738 * enough to insure forward progress through the 739 * directory. Complete checks can be run by setting 740 * "vfs.e2fs.dirchk" to be true. 741 */ 742 if (ep->e2d_reclen == 0 || 743 (dirchk && ext2_dirbadentry(vdp, ep, offset))) { 744 int i; 745 746 ext2_dirbad(ip, *offp, "mangled entry"); 747 i = bsize - (offset & (bsize - 1)); 748 *offp += i; 749 offset += i; 750 continue; 751 } 752 753 /* 754 * If an appropriate sized slot has not yet been found, 755 * check to see if one is available. Also accumulate space 756 * in the current block so that we can determine if 757 * compaction is viable. 758 */ 759 if (ssp->slotstatus != FOUND) { 760 int size = ep->e2d_reclen; 761 762 if (ep->e2d_ino != 0) 763 size -= EXT2_DIR_REC_LEN(ep->e2d_namlen); 764 else if (ext2_is_dirent_tail(ip, ep)) 765 size -= sizeof(struct ext2fs_direct_tail); 766 if (size > 0) { 767 if (size >= ssp->slotneeded) { 768 ssp->slotstatus = FOUND; 769 ssp->slotoffset = *offp; 770 ssp->slotsize = ep->e2d_reclen; 771 } else if (ssp->slotstatus == NONE) { 772 ssp->slotfreespace += size; 773 if (ssp->slotoffset == -1) 774 ssp->slotoffset = *offp; 775 if (ssp->slotfreespace >= ssp->slotneeded) { 776 ssp->slotstatus = COMPACT; 777 ssp->slotsize = *offp + 778 ep->e2d_reclen - 779 ssp->slotoffset; 780 } 781 } 782 } 783 } 784 /* 785 * Check for a name match. 786 */ 787 if (ep->e2d_ino) { 788 namlen = ep->e2d_namlen; 789 if (namlen == namelen && 790 !bcmp(name, ep->e2d_name, (unsigned)namlen)) { 791 /* 792 * Save directory entry's inode number and 793 * reclen in ndp->ni_ufs area, and release 794 * directory buffer. 795 */ 796 *foundp = 1; 797 return (0); 798 } 799 } 800 *prevoffp = *offp; 801 *offp += ep->e2d_reclen; 802 offset += ep->e2d_reclen; 803 *entryoffsetinblockp = offset; 804 if (ep->e2d_ino) 805 *endusefulp = *offp; 806 /* 807 * Get pointer to the next entry. 808 */ 809 ep = (struct ext2fs_direct_2 *)((char *)data + offset); 810 } 811 812 return (0); 813 } 814 815 void 816 ext2_dirbad(struct inode *ip, doff_t offset, char *how) 817 { 818 struct mount *mp; 819 820 mp = ITOV(ip)->v_mount; 821 if ((mp->mnt_flag & MNT_RDONLY) == 0) 822 panic("ext2_dirbad: %s: bad dir ino %ju at offset %ld: %s\n", 823 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number, 824 (long)offset, how); 825 else 826 SDT_PROBE4(ext2fs, , trace, ext2_dirbad_error, 827 mp->mnt_stat.f_mntonname, ip->i_number, offset, how); 828 } 829 830 /* 831 * Do consistency checking on a directory entry: 832 * record length must be multiple of 4 833 * entry must fit in rest of its DIRBLKSIZ block 834 * record must be large enough to contain entry 835 * name is not longer than MAXNAMLEN 836 * name must be as long as advertised, and null terminated 837 */ 838 /* 839 * changed so that it confirms to ext2_check_dir_entry 840 */ 841 static int 842 ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2 *de, 843 int entryoffsetinblock) 844 { 845 int DIRBLKSIZ = VTOI(dp)->i_e2fs->e2fs_bsize; 846 847 char *error_msg = NULL; 848 849 if (de->e2d_reclen < EXT2_DIR_REC_LEN(1)) 850 error_msg = "rec_len is smaller than minimal"; 851 else if (de->e2d_reclen % 4 != 0) 852 error_msg = "rec_len % 4 != 0"; 853 else if (de->e2d_reclen < EXT2_DIR_REC_LEN(de->e2d_namlen)) 854 error_msg = "reclen is too small for name_len"; 855 else if (entryoffsetinblock + de->e2d_reclen > DIRBLKSIZ) 856 error_msg = "directory entry across blocks"; 857 /* else LATER 858 if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count) 859 error_msg = "inode out of bounds"; 860 */ 861 862 if (error_msg != NULL) { 863 SDT_PROBE5(ext2fs, , trace, ext2_dirbadentry_error, 864 error_msg, entryoffsetinblock, 865 de->e2d_ino, de->e2d_reclen, de->e2d_namlen); 866 } 867 return error_msg == NULL ? 0 : 1; 868 } 869 870 /* 871 * Insert an entry into the fresh directory block. 872 * Initialize entry tail if the metadata_csum feature is turned on. 873 */ 874 static int 875 ext2_add_first_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry, 876 struct componentname *cnp) 877 { 878 struct inode *dp; 879 struct iovec aiov; 880 struct uio auio; 881 char* buf = NULL; 882 int dirblksize, error; 883 884 dp = VTOI(dvp); 885 dirblksize = dp->i_e2fs->e2fs_bsize; 886 887 if (dp->i_offset & (dirblksize - 1)) 888 panic("ext2_add_first_entry: bad directory offset"); 889 890 if (EXT2_HAS_RO_COMPAT_FEATURE(dp->i_e2fs, 891 EXT2F_ROCOMPAT_METADATA_CKSUM)) { 892 entry->e2d_reclen = dirblksize - sizeof(struct ext2fs_direct_tail); 893 buf = malloc(dirblksize, M_TEMP, M_WAITOK); 894 if (!buf) { 895 error = ENOMEM; 896 goto out; 897 } 898 memcpy(buf, entry, EXT2_DIR_REC_LEN(entry->e2d_namlen)); 899 ext2_init_dirent_tail(EXT2_DIRENT_TAIL(buf, dirblksize)); 900 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)buf); 901 902 auio.uio_offset = dp->i_offset; 903 auio.uio_resid = dirblksize; 904 aiov.iov_len = auio.uio_resid; 905 aiov.iov_base = (caddr_t)buf; 906 } else { 907 entry->e2d_reclen = dirblksize; 908 auio.uio_offset = dp->i_offset; 909 auio.uio_resid = EXT2_DIR_REC_LEN(entry->e2d_namlen); 910 aiov.iov_len = auio.uio_resid; 911 aiov.iov_base = (caddr_t)entry; 912 } 913 914 auio.uio_iov = &aiov; 915 auio.uio_iovcnt = 1; 916 auio.uio_rw = UIO_WRITE; 917 auio.uio_segflg = UIO_SYSSPACE; 918 auio.uio_td = (struct thread *)0; 919 error = VOP_WRITE(dvp, &auio, IO_SYNC, cnp->cn_cred); 920 if (error) 921 goto out; 922 923 dp->i_size = roundup2(dp->i_size, dirblksize); 924 dp->i_flag |= IN_CHANGE; 925 926 out: 927 free(buf, M_TEMP); 928 return (error); 929 930 } 931 932 /* 933 * Write a directory entry after a call to namei, using the parameters 934 * that it left in nameidata. The argument ip is the inode which the new 935 * directory entry will refer to. Dvp is a pointer to the directory to 936 * be written, which was left locked by namei. Remaining parameters 937 * (dp->i_offset, dp->i_count) indicate how the space for the new 938 * entry is to be obtained. 939 */ 940 int 941 ext2_direnter(struct inode *ip, struct vnode *dvp, struct componentname *cnp) 942 { 943 struct inode *dp; 944 struct ext2fs_direct_2 newdir; 945 int DIRBLKSIZ = ip->i_e2fs->e2fs_bsize; 946 int error; 947 948 949 #ifdef INVARIANTS 950 if ((cnp->cn_flags & SAVENAME) == 0) 951 panic("ext2_direnter: missing name"); 952 #endif 953 dp = VTOI(dvp); 954 newdir.e2d_ino = ip->i_number; 955 newdir.e2d_namlen = cnp->cn_namelen; 956 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 957 EXT2F_INCOMPAT_FTYPE)) 958 newdir.e2d_type = DTTOFT(IFTODT(ip->i_mode)); 959 else 960 newdir.e2d_type = EXT2_FT_UNKNOWN; 961 bcopy(cnp->cn_nameptr, newdir.e2d_name, (unsigned)cnp->cn_namelen + 1); 962 963 if (ext2_htree_has_idx(dp)) { 964 error = ext2_htree_add_entry(dvp, &newdir, cnp); 965 if (error) { 966 dp->i_flag &= ~IN_E3INDEX; 967 dp->i_flag |= IN_CHANGE | IN_UPDATE; 968 } 969 return (error); 970 } 971 972 if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) && 973 !ext2_htree_has_idx(dp)) { 974 if ((dp->i_size / DIRBLKSIZ) == 1 && 975 dp->i_offset == DIRBLKSIZ) { 976 /* 977 * Making indexed directory when one block is not 978 * enough to save all entries. 979 */ 980 return ext2_htree_create_index(dvp, cnp, &newdir); 981 } 982 } 983 984 /* 985 * If dp->i_count is 0, then namei could find no 986 * space in the directory. Here, dp->i_offset will 987 * be on a directory block boundary and we will write the 988 * new entry into a fresh block. 989 */ 990 if (dp->i_count == 0) 991 return ext2_add_first_entry(dvp, &newdir, cnp); 992 993 error = ext2_add_entry(dvp, &newdir); 994 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size) 995 error = ext2_truncate(dvp, (off_t)dp->i_endoff, IO_SYNC, 996 cnp->cn_cred, cnp->cn_thread); 997 return (error); 998 } 999 1000 /* 1001 * Insert an entry into the directory block. 1002 * Compact the contents. 1003 */ 1004 int 1005 ext2_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry) 1006 { 1007 struct ext2fs_direct_2 *ep, *nep; 1008 struct inode *dp; 1009 struct buf *bp; 1010 u_int dsize; 1011 int error, loc, newentrysize, spacefree; 1012 char *dirbuf; 1013 1014 dp = VTOI(dvp); 1015 1016 /* 1017 * If dp->i_count is non-zero, then namei found space 1018 * for the new entry in the range dp->i_offset to 1019 * dp->i_offset + dp->i_count in the directory. 1020 * To use this space, we may have to compact the entries located 1021 * there, by copying them together towards the beginning of the 1022 * block, leaving the free space in one usable chunk at the end. 1023 */ 1024 1025 /* 1026 * Increase size of directory if entry eats into new space. 1027 * This should never push the size past a new multiple of 1028 * DIRBLKSIZE. 1029 * 1030 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN. 1031 */ 1032 if (dp->i_offset + dp->i_count > dp->i_size) 1033 dp->i_size = dp->i_offset + dp->i_count; 1034 /* 1035 * Get the block containing the space for the new directory entry. 1036 */ 1037 if ((error = ext2_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, 1038 &bp)) != 0) 1039 return (error); 1040 /* 1041 * Find space for the new entry. In the simple case, the entry at 1042 * offset base will have the space. If it does not, then namei 1043 * arranged that compacting the region dp->i_offset to 1044 * dp->i_offset + dp->i_count would yield the 1045 * space. 1046 */ 1047 newentrysize = EXT2_DIR_REC_LEN(entry->e2d_namlen); 1048 ep = (struct ext2fs_direct_2 *)dirbuf; 1049 dsize = EXT2_DIR_REC_LEN(ep->e2d_namlen); 1050 spacefree = ep->e2d_reclen - dsize; 1051 for (loc = ep->e2d_reclen; loc < dp->i_count; ) { 1052 nep = (struct ext2fs_direct_2 *)(dirbuf + loc); 1053 if (ep->e2d_ino) { 1054 /* trim the existing slot */ 1055 ep->e2d_reclen = dsize; 1056 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1057 } else { 1058 /* overwrite; nothing there; header is ours */ 1059 spacefree += dsize; 1060 } 1061 dsize = EXT2_DIR_REC_LEN(nep->e2d_namlen); 1062 spacefree += nep->e2d_reclen - dsize; 1063 loc += nep->e2d_reclen; 1064 bcopy((caddr_t)nep, (caddr_t)ep, dsize); 1065 } 1066 /* 1067 * Update the pointer fields in the previous entry (if any), 1068 * copy in the new entry, and write out the block. 1069 */ 1070 if (ep->e2d_ino == 0) { 1071 if (spacefree + dsize < newentrysize) 1072 panic("ext2_direnter: compact1"); 1073 entry->e2d_reclen = spacefree + dsize; 1074 } else { 1075 if (spacefree < newentrysize) 1076 panic("ext2_direnter: compact2"); 1077 entry->e2d_reclen = spacefree; 1078 ep->e2d_reclen = dsize; 1079 ep = (struct ext2fs_direct_2 *)((char *)ep + dsize); 1080 } 1081 bcopy((caddr_t)entry, (caddr_t)ep, (u_int)newentrysize); 1082 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1083 if (DOINGASYNC(dvp)) { 1084 bdwrite(bp); 1085 error = 0; 1086 } else { 1087 error = bwrite(bp); 1088 } 1089 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1090 return (error); 1091 } 1092 1093 /* 1094 * Remove a directory entry after a call to namei, using 1095 * the parameters which it left in nameidata. The entry 1096 * dp->i_offset contains the offset into the directory of the 1097 * entry to be eliminated. The dp->i_count field contains the 1098 * size of the previous record in the directory. If this 1099 * is 0, the first entry is being deleted, so we need only 1100 * zero the inode number to mark the entry as free. If the 1101 * entry is not the first in the directory, we must reclaim 1102 * the space of the now empty record by adding the record size 1103 * to the size of the previous entry. 1104 */ 1105 int 1106 ext2_dirremove(struct vnode *dvp, struct componentname *cnp) 1107 { 1108 struct inode *dp; 1109 struct ext2fs_direct_2 *ep, *rep; 1110 struct buf *bp; 1111 int error; 1112 1113 dp = VTOI(dvp); 1114 if (dp->i_count == 0) { 1115 /* 1116 * First entry in block: set d_ino to zero. 1117 */ 1118 if ((error = 1119 ext2_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, 1120 &bp)) != 0) 1121 return (error); 1122 ep->e2d_ino = 0; 1123 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1124 error = bwrite(bp); 1125 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1126 return (error); 1127 } 1128 /* 1129 * Collapse new free space into previous entry. 1130 */ 1131 if ((error = ext2_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count), 1132 (char **)&ep, &bp)) != 0) 1133 return (error); 1134 1135 /* Set 'rep' to the entry being removed. */ 1136 if (dp->i_count == 0) 1137 rep = ep; 1138 else 1139 rep = (struct ext2fs_direct_2 *)((char *)ep + ep->e2d_reclen); 1140 ep->e2d_reclen += rep->e2d_reclen; 1141 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1142 if (DOINGASYNC(dvp) && dp->i_count != 0) 1143 bdwrite(bp); 1144 else 1145 error = bwrite(bp); 1146 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1147 return (error); 1148 } 1149 1150 /* 1151 * Rewrite an existing directory entry to point at the inode 1152 * supplied. The parameters describing the directory entry are 1153 * set up by a call to namei. 1154 */ 1155 int 1156 ext2_dirrewrite(struct inode *dp, struct inode *ip, struct componentname *cnp) 1157 { 1158 struct buf *bp; 1159 struct ext2fs_direct_2 *ep; 1160 struct vnode *vdp = ITOV(dp); 1161 int error; 1162 1163 if ((error = ext2_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, 1164 &bp)) != 0) 1165 return (error); 1166 ep->e2d_ino = ip->i_number; 1167 if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs, 1168 EXT2F_INCOMPAT_FTYPE)) 1169 ep->e2d_type = DTTOFT(IFTODT(ip->i_mode)); 1170 else 1171 ep->e2d_type = EXT2_FT_UNKNOWN; 1172 ext2_dirent_csum_set(dp, (struct ext2fs_direct_2 *)bp->b_data); 1173 error = bwrite(bp); 1174 dp->i_flag |= IN_CHANGE | IN_UPDATE; 1175 return (error); 1176 } 1177 1178 /* 1179 * Check if a directory is empty or not. 1180 * Inode supplied must be locked. 1181 * 1182 * Using a struct dirtemplate here is not precisely 1183 * what we want, but better than using a struct direct. 1184 * 1185 * NB: does not handle corrupted directories. 1186 */ 1187 int 1188 ext2_dirempty(struct inode *ip, ino_t parentino, struct ucred *cred) 1189 { 1190 off_t off; 1191 struct dirtemplate dbuf; 1192 struct ext2fs_direct_2 *dp = (struct ext2fs_direct_2 *)&dbuf; 1193 int error, namlen; 1194 ssize_t count; 1195 #define MINDIRSIZ (sizeof(struct dirtemplate) / 2) 1196 1197 for (off = 0; off < ip->i_size; off += dp->e2d_reclen) { 1198 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, 1199 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred, 1200 NOCRED, &count, (struct thread *)0); 1201 /* 1202 * Since we read MINDIRSIZ, residual must 1203 * be 0 unless we're at end of file. 1204 */ 1205 if (error || count != 0) 1206 return (0); 1207 /* avoid infinite loops */ 1208 if (dp->e2d_reclen == 0) 1209 return (0); 1210 /* skip empty entries */ 1211 if (dp->e2d_ino == 0) 1212 continue; 1213 /* accept only "." and ".." */ 1214 namlen = dp->e2d_namlen; 1215 if (namlen > 2) 1216 return (0); 1217 if (dp->e2d_name[0] != '.') 1218 return (0); 1219 /* 1220 * At this point namlen must be 1 or 2. 1221 * 1 implies ".", 2 implies ".." if second 1222 * char is also "." 1223 */ 1224 if (namlen == 1) 1225 continue; 1226 if (dp->e2d_name[1] == '.' && dp->e2d_ino == parentino) 1227 continue; 1228 return (0); 1229 } 1230 return (1); 1231 } 1232 1233 /* 1234 * Check if source directory is in the path of the target directory. 1235 * Target is supplied locked, source is unlocked. 1236 * The target is always vput before returning. 1237 */ 1238 int 1239 ext2_checkpath(struct inode *source, struct inode *target, struct ucred *cred) 1240 { 1241 struct vnode *vp; 1242 int error, namlen; 1243 struct dirtemplate dirbuf; 1244 1245 vp = ITOV(target); 1246 if (target->i_number == source->i_number) { 1247 error = EEXIST; 1248 goto out; 1249 } 1250 if (target->i_number == EXT2_ROOTINO) { 1251 error = 0; 1252 goto out; 1253 } 1254 1255 for (;;) { 1256 if (vp->v_type != VDIR) { 1257 error = ENOTDIR; 1258 break; 1259 } 1260 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf, 1261 sizeof(struct dirtemplate), (off_t)0, UIO_SYSSPACE, 1262 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, 1263 NULL); 1264 if (error != 0) 1265 break; 1266 namlen = dirbuf.dotdot_type; /* like ufs little-endian */ 1267 if (namlen != 2 || 1268 dirbuf.dotdot_name[0] != '.' || 1269 dirbuf.dotdot_name[1] != '.') { 1270 error = ENOTDIR; 1271 break; 1272 } 1273 if (dirbuf.dotdot_ino == source->i_number) { 1274 error = EINVAL; 1275 break; 1276 } 1277 if (dirbuf.dotdot_ino == EXT2_ROOTINO) 1278 break; 1279 vput(vp); 1280 if ((error = VFS_VGET(vp->v_mount, dirbuf.dotdot_ino, 1281 LK_EXCLUSIVE, &vp)) != 0) { 1282 vp = NULL; 1283 break; 1284 } 1285 } 1286 1287 out: 1288 if (error == ENOTDIR) 1289 SDT_PROBE2(ext2fs, , lookup, trace, 1, 1290 "checkpath: .. not a directory"); 1291 if (vp != NULL) 1292 vput(vp); 1293 return (error); 1294 }
Cache object: 9f7f2582e9bc92744252df54ea09bf2f
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