vfs_lookup.c revision 1.19
1 /* $NetBSD: vfs_lookup.c,v 1.19 1996/10/13 02:32:52 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)vfs_lookup.c 8.6 (Berkeley) 11/21/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/syslimits.h> 46 #include <sys/time.h> 47 #include <sys/namei.h> 48 #include <sys/vnode.h> 49 #include <sys/mount.h> 50 #include <sys/errno.h> 51 #include <sys/malloc.h> 52 #include <sys/filedesc.h> 53 #include <sys/proc.h> 54 55 #ifdef KTRACE 56 #include <sys/ktrace.h> 57 #endif 58 59 /* 60 * Convert a pathname into a pointer to a locked inode. 61 * 62 * The FOLLOW flag is set when symbolic links are to be followed 63 * when they occur at the end of the name translation process. 64 * Symbolic links are always followed for all other pathname 65 * components other than the last. 66 * 67 * The segflg defines whether the name is to be copied from user 68 * space or kernel space. 69 * 70 * Overall outline of namei: 71 * 72 * copy in name 73 * get starting directory 74 * while (!done && !error) { 75 * call lookup to search path. 76 * if symbolic link, massage name in buffer and continue 77 * } 78 */ 79 int 80 namei(ndp) 81 register struct nameidata *ndp; 82 { 83 register struct filedesc *fdp; /* pointer to file descriptor state */ 84 register char *cp; /* pointer into pathname argument */ 85 register struct vnode *dp; /* the directory we are searching */ 86 struct iovec aiov; /* uio for reading symbolic links */ 87 struct uio auio; 88 int error, linklen; 89 struct componentname *cnp = &ndp->ni_cnd; 90 91 ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_proc->p_ucred; 92 #ifdef DIAGNOSTIC 93 if (!cnp->cn_cred || !cnp->cn_proc) 94 panic ("namei: bad cred/proc"); 95 if (cnp->cn_nameiop & (~OPMASK)) 96 panic ("namei: nameiop contaminated with flags"); 97 if (cnp->cn_flags & OPMASK) 98 panic ("namei: flags contaminated with nameiops"); 99 #endif 100 fdp = cnp->cn_proc->p_fd; 101 102 /* 103 * Get a buffer for the name to be translated, and copy the 104 * name into the buffer. 105 */ 106 if ((cnp->cn_flags & HASBUF) == 0) 107 MALLOC(cnp->cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK); 108 if (ndp->ni_segflg == UIO_SYSSPACE) 109 error = copystr(ndp->ni_dirp, cnp->cn_pnbuf, 110 MAXPATHLEN, &ndp->ni_pathlen); 111 else 112 error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, 113 MAXPATHLEN, &ndp->ni_pathlen); 114 if (error) { 115 free(cnp->cn_pnbuf, M_NAMEI); 116 ndp->ni_vp = NULL; 117 return (error); 118 } 119 ndp->ni_loopcnt = 0; 120 #ifdef KTRACE 121 if (KTRPOINT(cnp->cn_proc, KTR_NAMEI)) 122 ktrnamei(cnp->cn_proc->p_tracep, cnp->cn_pnbuf); 123 #endif 124 125 /* 126 * Get starting point for the translation. 127 */ 128 if ((ndp->ni_rootdir = fdp->fd_rdir) == NULL) 129 ndp->ni_rootdir = rootvnode; 130 dp = fdp->fd_cdir; 131 VREF(dp); 132 for (;;) { 133 /* 134 * Check if root directory should replace current directory. 135 * Done at start of translation and after symbolic link. 136 */ 137 cnp->cn_nameptr = cnp->cn_pnbuf; 138 if (*(cnp->cn_nameptr) == '/') { 139 vrele(dp); 140 while (*(cnp->cn_nameptr) == '/') { 141 cnp->cn_nameptr++; 142 ndp->ni_pathlen--; 143 } 144 dp = ndp->ni_rootdir; 145 VREF(dp); 146 } 147 ndp->ni_startdir = dp; 148 if ((error = lookup(ndp)) != 0) { 149 FREE(cnp->cn_pnbuf, M_NAMEI); 150 return (error); 151 } 152 /* 153 * Check for symbolic link 154 */ 155 if ((cnp->cn_flags & ISSYMLINK) == 0) { 156 if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) 157 FREE(cnp->cn_pnbuf, M_NAMEI); 158 else 159 cnp->cn_flags |= HASBUF; 160 return (0); 161 } 162 if ((cnp->cn_flags & LOCKPARENT) && ndp->ni_pathlen == 1) 163 VOP_UNLOCK(ndp->ni_dvp); 164 if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { 165 error = ELOOP; 166 break; 167 } 168 if (ndp->ni_pathlen > 1) 169 MALLOC(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); 170 else 171 cp = cnp->cn_pnbuf; 172 aiov.iov_base = cp; 173 aiov.iov_len = MAXPATHLEN; 174 auio.uio_iov = &aiov; 175 auio.uio_iovcnt = 1; 176 auio.uio_offset = 0; 177 auio.uio_rw = UIO_READ; 178 auio.uio_segflg = UIO_SYSSPACE; 179 auio.uio_procp = (struct proc *)0; 180 auio.uio_resid = MAXPATHLEN; 181 error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred); 182 if (error) { 183 if (ndp->ni_pathlen > 1) 184 free(cp, M_NAMEI); 185 break; 186 } 187 linklen = MAXPATHLEN - auio.uio_resid; 188 if (linklen + ndp->ni_pathlen >= MAXPATHLEN) { 189 if (ndp->ni_pathlen > 1) 190 free(cp, M_NAMEI); 191 error = ENAMETOOLONG; 192 break; 193 } 194 if (ndp->ni_pathlen > 1) { 195 bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen); 196 FREE(cnp->cn_pnbuf, M_NAMEI); 197 cnp->cn_pnbuf = cp; 198 } else 199 cnp->cn_pnbuf[linklen] = '\0'; 200 ndp->ni_pathlen += linklen; 201 vput(ndp->ni_vp); 202 dp = ndp->ni_dvp; 203 } 204 FREE(cnp->cn_pnbuf, M_NAMEI); 205 vrele(ndp->ni_dvp); 206 vput(ndp->ni_vp); 207 ndp->ni_vp = NULL; 208 return (error); 209 } 210 211 /* 212 * Search a pathname. 213 * This is a very central and rather complicated routine. 214 * 215 * The pathname is pointed to by ni_ptr and is of length ni_pathlen. 216 * The starting directory is taken from ni_startdir. The pathname is 217 * descended until done, or a symbolic link is encountered. The variable 218 * ni_more is clear if the path is completed; it is set to one if a 219 * symbolic link needing interpretation is encountered. 220 * 221 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on 222 * whether the name is to be looked up, created, renamed, or deleted. 223 * When CREATE, RENAME, or DELETE is specified, information usable in 224 * creating, renaming, or deleting a directory entry may be calculated. 225 * If flag has LOCKPARENT or'ed into it, the parent directory is returned 226 * locked. If flag has WANTPARENT or'ed into it, the parent directory is 227 * returned unlocked. Otherwise the parent directory is not returned. If 228 * the target of the pathname exists and LOCKLEAF is or'ed into the flag 229 * the target is returned locked, otherwise it is returned unlocked. 230 * When creating or renaming and LOCKPARENT is specified, the target may not 231 * be ".". When deleting and LOCKPARENT is specified, the target may be ".". 232 * 233 * Overall outline of lookup: 234 * 235 * dirloop: 236 * identify next component of name at ndp->ni_ptr 237 * handle degenerate case where name is null string 238 * if .. and crossing mount points and on mounted filesys, find parent 239 * call VOP_LOOKUP routine for next component name 240 * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set 241 * component vnode returned in ni_vp (if it exists), locked. 242 * if result vnode is mounted on and crossing mount points, 243 * find mounted on vnode 244 * if more components of name, do next level at dirloop 245 * return the answer in ni_vp, locked if LOCKLEAF set 246 * if LOCKPARENT set, return locked parent in ni_dvp 247 * if WANTPARENT set, return unlocked parent in ni_dvp 248 */ 249 int 250 lookup(ndp) 251 register struct nameidata *ndp; 252 { 253 register char *cp; /* pointer into pathname argument */ 254 register struct vnode *dp = 0; /* the directory we are searching */ 255 struct vnode *tdp; /* saved dp */ 256 struct mount *mp; /* mount table entry */ 257 int docache; /* == 0 do not cache last component */ 258 int wantparent; /* 1 => wantparent or lockparent flag */ 259 int rdonly; /* lookup read-only flag bit */ 260 int error = 0; 261 struct componentname *cnp = &ndp->ni_cnd; 262 263 /* 264 * Setup: break out flag bits into variables. 265 */ 266 wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); 267 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; 268 if (cnp->cn_nameiop == DELETE || 269 (wantparent && cnp->cn_nameiop != CREATE)) 270 docache = 0; 271 rdonly = cnp->cn_flags & RDONLY; 272 ndp->ni_dvp = NULL; 273 cnp->cn_flags &= ~ISSYMLINK; 274 dp = ndp->ni_startdir; 275 ndp->ni_startdir = NULLVP; 276 VOP_LOCK(dp); 277 278 dirloop: 279 /* 280 * Search a new directory. 281 * 282 * The cn_hash value is for use by vfs_cache. 283 * The last component of the filename is left accessible via 284 * cnp->cn_nameptr for callers that need the name. Callers needing 285 * the name set the SAVENAME flag. When done, they assume 286 * responsibility for freeing the pathname buffer. 287 */ 288 cnp->cn_consume = 0; 289 cnp->cn_hash = 0; 290 for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) 291 cnp->cn_hash += (unsigned char)*cp; 292 cnp->cn_namelen = cp - cnp->cn_nameptr; 293 if (cnp->cn_namelen > NAME_MAX) { 294 error = ENAMETOOLONG; 295 goto bad; 296 } 297 #ifdef NAMEI_DIAGNOSTIC 298 { char c = *cp; 299 *cp = '\0'; 300 printf("{%s}: ", cnp->cn_nameptr); 301 *cp = c; } 302 #endif 303 ndp->ni_pathlen -= cnp->cn_namelen; 304 ndp->ni_next = cp; 305 cnp->cn_flags |= MAKEENTRY; 306 if (*cp == '\0' && docache == 0) 307 cnp->cn_flags &= ~MAKEENTRY; 308 if (cnp->cn_namelen == 2 && 309 cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') 310 cnp->cn_flags |= ISDOTDOT; 311 else 312 cnp->cn_flags &= ~ISDOTDOT; 313 if (*ndp->ni_next == 0) 314 cnp->cn_flags |= ISLASTCN; 315 else 316 cnp->cn_flags &= ~ISLASTCN; 317 318 319 /* 320 * Check for degenerate name (e.g. / or "") 321 * which is a way of talking about a directory, 322 * e.g. like "/." or ".". 323 */ 324 if (cnp->cn_nameptr[0] == '\0') { 325 if (dp->v_type != VDIR) { 326 error = ENOTDIR; 327 goto bad; 328 } 329 if (cnp->cn_nameiop != LOOKUP) { 330 error = EISDIR; 331 goto bad; 332 } 333 if (wantparent) { 334 ndp->ni_dvp = dp; 335 VREF(dp); 336 } 337 ndp->ni_vp = dp; 338 if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF))) 339 VOP_UNLOCK(dp); 340 if (cnp->cn_flags & SAVESTART) 341 panic("lookup: SAVESTART"); 342 return (0); 343 } 344 345 /* 346 * Handle "..": two special cases. 347 * 1. If at root directory (e.g. after chroot) 348 * or at absolute root directory 349 * then ignore it so can't get out. 350 * 2. If this vnode is the root of a mounted 351 * filesystem, then replace it with the 352 * vnode which was mounted on so we take the 353 * .. in the other file system. 354 */ 355 if (cnp->cn_flags & ISDOTDOT) { 356 for (;;) { 357 if (dp == ndp->ni_rootdir || dp == rootvnode) { 358 ndp->ni_dvp = dp; 359 ndp->ni_vp = dp; 360 VREF(dp); 361 goto nextname; 362 } 363 if ((dp->v_flag & VROOT) == 0 || 364 (cnp->cn_flags & NOCROSSMOUNT)) 365 break; 366 tdp = dp; 367 dp = dp->v_mount->mnt_vnodecovered; 368 vput(tdp); 369 VREF(dp); 370 VOP_LOCK(dp); 371 } 372 } 373 374 /* 375 * We now have a segment name to search for, and a directory to search. 376 */ 377 unionlookup: 378 ndp->ni_dvp = dp; 379 if ((error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp)) != 0) { 380 #ifdef DIAGNOSTIC 381 if (ndp->ni_vp != NULL) 382 panic("leaf should be empty"); 383 #endif 384 #ifdef NAMEI_DIAGNOSTIC 385 printf("not found\n"); 386 #endif 387 if ((error == ENOENT) && 388 (dp->v_flag & VROOT) && 389 (dp->v_mount->mnt_flag & MNT_UNION)) { 390 tdp = dp; 391 dp = dp->v_mount->mnt_vnodecovered; 392 vput(tdp); 393 VREF(dp); 394 VOP_LOCK(dp); 395 goto unionlookup; 396 } 397 398 if (error != EJUSTRETURN) 399 goto bad; 400 /* 401 * If creating and at end of pathname, then can consider 402 * allowing file to be created. 403 */ 404 if (rdonly || (ndp->ni_dvp->v_mount->mnt_flag & MNT_RDONLY)) { 405 error = EROFS; 406 goto bad; 407 } 408 /* 409 * We return with ni_vp NULL to indicate that the entry 410 * doesn't currently exist, leaving a pointer to the 411 * (possibly locked) directory inode in ndp->ni_dvp. 412 */ 413 if (cnp->cn_flags & SAVESTART) { 414 ndp->ni_startdir = ndp->ni_dvp; 415 VREF(ndp->ni_startdir); 416 } 417 return (0); 418 } 419 #ifdef NAMEI_DIAGNOSTIC 420 printf("found\n"); 421 #endif 422 423 /* 424 * Take into account any additional components consumed by 425 * the underlying filesystem. 426 */ 427 if (cnp->cn_consume > 0) { 428 cnp->cn_nameptr += cnp->cn_consume; 429 ndp->ni_next += cnp->cn_consume; 430 ndp->ni_pathlen -= cnp->cn_consume; 431 cnp->cn_consume = 0; 432 } 433 434 dp = ndp->ni_vp; 435 /* 436 * Check to see if the vnode has been mounted on; 437 * if so find the root of the mounted file system. 438 */ 439 while (dp->v_type == VDIR && (mp = dp->v_mountedhere) && 440 (cnp->cn_flags & NOCROSSMOUNT) == 0) { 441 if (mp->mnt_flag & MNT_MLOCK) { 442 mp->mnt_flag |= MNT_MWAIT; 443 sleep((caddr_t)mp, PVFS); 444 continue; 445 } 446 if ((error = VFS_ROOT(dp->v_mountedhere, &tdp)) != 0) 447 goto bad2; 448 vput(dp); 449 ndp->ni_vp = dp = tdp; 450 } 451 452 /* 453 * Check for symbolic link 454 */ 455 if ((dp->v_type == VLNK) && 456 ((cnp->cn_flags & FOLLOW) || *ndp->ni_next == '/')) { 457 cnp->cn_flags |= ISSYMLINK; 458 return (0); 459 } 460 461 nextname: 462 /* 463 * Not a symbolic link. If more pathname, 464 * continue at next component, else return. 465 */ 466 if (*ndp->ni_next == '/') { 467 cnp->cn_nameptr = ndp->ni_next; 468 while (*cnp->cn_nameptr == '/') { 469 cnp->cn_nameptr++; 470 ndp->ni_pathlen--; 471 } 472 vrele(ndp->ni_dvp); 473 goto dirloop; 474 } 475 /* 476 * Check for read-only file systems. 477 */ 478 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 479 /* 480 * Disallow directory write attempts on read-only 481 * file systems. 482 */ 483 if (rdonly || (dp->v_mount->mnt_flag & MNT_RDONLY) || 484 (wantparent && 485 (ndp->ni_dvp->v_mount->mnt_flag & MNT_RDONLY))) { 486 error = EROFS; 487 goto bad2; 488 } 489 } 490 if (cnp->cn_flags & SAVESTART) { 491 ndp->ni_startdir = ndp->ni_dvp; 492 VREF(ndp->ni_startdir); 493 } 494 if (!wantparent) 495 vrele(ndp->ni_dvp); 496 if ((cnp->cn_flags & LOCKLEAF) == 0) 497 VOP_UNLOCK(dp); 498 return (0); 499 500 bad2: 501 if ((cnp->cn_flags & LOCKPARENT) && *ndp->ni_next == '\0') 502 VOP_UNLOCK(ndp->ni_dvp); 503 vrele(ndp->ni_dvp); 504 bad: 505 vput(dp); 506 ndp->ni_vp = NULL; 507 return (error); 508 } 509 510 /* 511 * Reacquire a path name component. 512 */ 513 int 514 relookup(dvp, vpp, cnp) 515 struct vnode *dvp, **vpp; 516 struct componentname *cnp; 517 { 518 register struct vnode *dp = 0; /* the directory we are searching */ 519 int docache; /* == 0 do not cache last component */ 520 int wantparent; /* 1 => wantparent or lockparent flag */ 521 int rdonly; /* lookup read-only flag bit */ 522 int error = 0; 523 #ifdef NAMEI_DIAGNOSTIC 524 int newhash; /* DEBUG: check name hash */ 525 char *cp; /* DEBUG: check name ptr/len */ 526 #endif 527 528 /* 529 * Setup: break out flag bits into variables. 530 */ 531 wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT); 532 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; 533 if (cnp->cn_nameiop == DELETE || 534 (wantparent && cnp->cn_nameiop != CREATE)) 535 docache = 0; 536 rdonly = cnp->cn_flags & RDONLY; 537 cnp->cn_flags &= ~ISSYMLINK; 538 dp = dvp; 539 VOP_LOCK(dp); 540 541 /* dirloop: */ 542 /* 543 * Search a new directory. 544 * 545 * The cn_hash value is for use by vfs_cache. 546 * The last component of the filename is left accessible via 547 * cnp->cn_nameptr for callers that need the name. Callers needing 548 * the name set the SAVENAME flag. When done, they assume 549 * responsibility for freeing the pathname buffer. 550 */ 551 #ifdef NAMEI_DIAGNOSTIC 552 for (newhash = 0, cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) 553 newhash += (unsigned char)*cp; 554 if (newhash != cnp->cn_hash) 555 panic("relookup: bad hash"); 556 if (cnp->cn_namelen != cp - cnp->cn_nameptr) 557 panic ("relookup: bad len"); 558 if (*cp != 0) 559 panic("relookup: not last component"); 560 printf("{%s}: ", cnp->cn_nameptr); 561 #endif 562 563 /* 564 * Check for degenerate name (e.g. / or "") 565 * which is a way of talking about a directory, 566 * e.g. like "/." or ".". 567 */ 568 if (cnp->cn_nameptr[0] == '\0') { 569 if (dp->v_type != VDIR) { 570 error = ENOTDIR; 571 goto bad; 572 } 573 if (cnp->cn_nameiop != LOOKUP || wantparent) { 574 error = EISDIR; 575 goto bad; 576 } 577 if (!(cnp->cn_flags & LOCKLEAF)) 578 VOP_UNLOCK(dp); 579 *vpp = dp; 580 if (cnp->cn_flags & SAVESTART) 581 panic("lookup: SAVESTART"); 582 return (0); 583 } 584 585 if (cnp->cn_flags & ISDOTDOT) 586 panic ("relookup: lookup on dot-dot"); 587 588 /* 589 * We now have a segment name to search for, and a directory to search. 590 */ 591 if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) { 592 #ifdef DIAGNOSTIC 593 if (*vpp != NULL) 594 panic("leaf should be empty"); 595 #endif 596 if (error != EJUSTRETURN) 597 goto bad; 598 /* 599 * If creating and at end of pathname, then can consider 600 * allowing file to be created. 601 */ 602 if (rdonly || (dvp->v_mount->mnt_flag & MNT_RDONLY)) { 603 error = EROFS; 604 goto bad; 605 } 606 /* ASSERT(dvp == ndp->ni_startdir) */ 607 if (cnp->cn_flags & SAVESTART) 608 VREF(dvp); 609 /* 610 * We return with ni_vp NULL to indicate that the entry 611 * doesn't currently exist, leaving a pointer to the 612 * (possibly locked) directory inode in ndp->ni_dvp. 613 */ 614 return (0); 615 } 616 dp = *vpp; 617 618 #ifdef DIAGNOSTIC 619 /* 620 * Check for symbolic link 621 */ 622 if (dp->v_type == VLNK && (cnp->cn_flags & FOLLOW)) 623 panic ("relookup: symlink found.\n"); 624 #endif 625 626 /* 627 * Check for read-only file systems. 628 */ 629 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 630 /* 631 * Disallow directory write attempts on read-only 632 * file systems. 633 */ 634 if (rdonly || (dp->v_mount->mnt_flag & MNT_RDONLY) || 635 (wantparent && 636 (dvp->v_mount->mnt_flag & MNT_RDONLY))) { 637 error = EROFS; 638 goto bad2; 639 } 640 } 641 /* ASSERT(dvp == ndp->ni_startdir) */ 642 if (cnp->cn_flags & SAVESTART) 643 VREF(dvp); 644 645 if (!wantparent) 646 vrele(dvp); 647 if ((cnp->cn_flags & LOCKLEAF) == 0) 648 VOP_UNLOCK(dp); 649 return (0); 650 651 bad2: 652 if ((cnp->cn_flags & LOCKPARENT) && (cnp->cn_flags & ISLASTCN)) 653 VOP_UNLOCK(dvp); 654 vrele(dvp); 655 bad: 656 vput(dp); 657 *vpp = NULL; 658 return (error); 659 } 660
Indexes created Sat Sep 20 22:09:52 GMT 2025