vfs_lookup.c revision 1.16
1 /* $NetBSD: vfs_lookup.c,v 1.16 1996/02/04 02:18:25 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 #include <kern/kern_extern.h> 60 61 /* 62 * Convert a pathname into a pointer to a locked inode. 63 * 64 * The FOLLOW flag is set when symbolic links are to be followed 65 * when they occur at the end of the name translation process. 66 * Symbolic links are always followed for all other pathname 67 * components other than the last. 68 * 69 * The segflg defines whether the name is to be copied from user 70 * space or kernel space. 71 * 72 * Overall outline of namei: 73 * 74 * copy in name 75 * get starting directory 76 * while (!done && !error) { 77 * call lookup to search path. 78 * if symbolic link, massage name in buffer and continue 79 * } 80 */ 81 int 82 namei(ndp) 83 register struct nameidata *ndp; 84 { 85 register struct filedesc *fdp; /* pointer to file descriptor state */ 86 register char *cp; /* pointer into pathname argument */ 87 register struct vnode *dp; /* the directory we are searching */ 88 struct iovec aiov; /* uio for reading symbolic links */ 89 struct uio auio; 90 int error, linklen; 91 struct componentname *cnp = &ndp->ni_cnd; 92 93 ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_proc->p_ucred; 94 #ifdef DIAGNOSTIC 95 if (!cnp->cn_cred || !cnp->cn_proc) 96 panic ("namei: bad cred/proc"); 97 if (cnp->cn_nameiop & (~OPMASK)) 98 panic ("namei: nameiop contaminated with flags"); 99 if (cnp->cn_flags & OPMASK) 100 panic ("namei: flags contaminated with nameiops"); 101 #endif 102 fdp = cnp->cn_proc->p_fd; 103 104 /* 105 * Get a buffer for the name to be translated, and copy the 106 * name into the buffer. 107 */ 108 if ((cnp->cn_flags & HASBUF) == 0) 109 MALLOC(cnp->cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK); 110 if (ndp->ni_segflg == UIO_SYSSPACE) 111 error = copystr(ndp->ni_dirp, cnp->cn_pnbuf, 112 MAXPATHLEN, &ndp->ni_pathlen); 113 else 114 error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, 115 MAXPATHLEN, &ndp->ni_pathlen); 116 if (error) { 117 free(cnp->cn_pnbuf, M_NAMEI); 118 ndp->ni_vp = NULL; 119 return (error); 120 } 121 ndp->ni_loopcnt = 0; 122 #ifdef KTRACE 123 if (KTRPOINT(cnp->cn_proc, KTR_NAMEI)) 124 ktrnamei(cnp->cn_proc->p_tracep, cnp->cn_pnbuf); 125 #endif 126 127 /* 128 * Get starting point for the translation. 129 */ 130 if ((ndp->ni_rootdir = fdp->fd_rdir) == NULL) 131 ndp->ni_rootdir = rootvnode; 132 dp = fdp->fd_cdir; 133 VREF(dp); 134 for (;;) { 135 /* 136 * Check if root directory should replace current directory. 137 * Done at start of translation and after symbolic link. 138 */ 139 cnp->cn_nameptr = cnp->cn_pnbuf; 140 if (*(cnp->cn_nameptr) == '/') { 141 vrele(dp); 142 while (*(cnp->cn_nameptr) == '/') { 143 cnp->cn_nameptr++; 144 ndp->ni_pathlen--; 145 } 146 dp = ndp->ni_rootdir; 147 VREF(dp); 148 } 149 ndp->ni_startdir = dp; 150 if ((error = lookup(ndp)) != 0) { 151 FREE(cnp->cn_pnbuf, M_NAMEI); 152 return (error); 153 } 154 /* 155 * Check for symbolic link 156 */ 157 if ((cnp->cn_flags & ISSYMLINK) == 0) { 158 if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) 159 FREE(cnp->cn_pnbuf, M_NAMEI); 160 else 161 cnp->cn_flags |= HASBUF; 162 return (0); 163 } 164 if ((cnp->cn_flags & LOCKPARENT) && ndp->ni_pathlen == 1) 165 VOP_UNLOCK(ndp->ni_dvp); 166 if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { 167 error = ELOOP; 168 break; 169 } 170 if (ndp->ni_pathlen > 1) 171 MALLOC(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); 172 else 173 cp = cnp->cn_pnbuf; 174 aiov.iov_base = cp; 175 aiov.iov_len = MAXPATHLEN; 176 auio.uio_iov = &aiov; 177 auio.uio_iovcnt = 1; 178 auio.uio_offset = 0; 179 auio.uio_rw = UIO_READ; 180 auio.uio_segflg = UIO_SYSSPACE; 181 auio.uio_procp = (struct proc *)0; 182 auio.uio_resid = MAXPATHLEN; 183 error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred); 184 if (error) { 185 if (ndp->ni_pathlen > 1) 186 free(cp, M_NAMEI); 187 break; 188 } 189 linklen = MAXPATHLEN - auio.uio_resid; 190 if (linklen + ndp->ni_pathlen >= MAXPATHLEN) { 191 if (ndp->ni_pathlen > 1) 192 free(cp, M_NAMEI); 193 error = ENAMETOOLONG; 194 break; 195 } 196 if (ndp->ni_pathlen > 1) { 197 bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen); 198 FREE(cnp->cn_pnbuf, M_NAMEI); 199 cnp->cn_pnbuf = cp; 200 } else 201 cnp->cn_pnbuf[linklen] = '\0'; 202 ndp->ni_pathlen += linklen; 203 vput(ndp->ni_vp); 204 dp = ndp->ni_dvp; 205 } 206 FREE(cnp->cn_pnbuf, M_NAMEI); 207 vrele(ndp->ni_dvp); 208 vput(ndp->ni_vp); 209 ndp->ni_vp = NULL; 210 return (error); 211 } 212 213 /* 214 * Search a pathname. 215 * This is a very central and rather complicated routine. 216 * 217 * The pathname is pointed to by ni_ptr and is of length ni_pathlen. 218 * The starting directory is taken from ni_startdir. The pathname is 219 * descended until done, or a symbolic link is encountered. The variable 220 * ni_more is clear if the path is completed; it is set to one if a 221 * symbolic link needing interpretation is encountered. 222 * 223 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on 224 * whether the name is to be looked up, created, renamed, or deleted. 225 * When CREATE, RENAME, or DELETE is specified, information usable in 226 * creating, renaming, or deleting a directory entry may be calculated. 227 * If flag has LOCKPARENT or'ed into it, the parent directory is returned 228 * locked. If flag has WANTPARENT or'ed into it, the parent directory is 229 * returned unlocked. Otherwise the parent directory is not returned. If 230 * the target of the pathname exists and LOCKLEAF is or'ed into the flag 231 * the target is returned locked, otherwise it is returned unlocked. 232 * When creating or renaming and LOCKPARENT is specified, the target may not 233 * be ".". When deleting and LOCKPARENT is specified, the target may be ".". 234 * 235 * Overall outline of lookup: 236 * 237 * dirloop: 238 * identify next component of name at ndp->ni_ptr 239 * handle degenerate case where name is null string 240 * if .. and crossing mount points and on mounted filesys, find parent 241 * call VOP_LOOKUP routine for next component name 242 * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set 243 * component vnode returned in ni_vp (if it exists), locked. 244 * if result vnode is mounted on and crossing mount points, 245 * find mounted on vnode 246 * if more components of name, do next level at dirloop 247 * return the answer in ni_vp, locked if LOCKLEAF set 248 * if LOCKPARENT set, return locked parent in ni_dvp 249 * if WANTPARENT set, return unlocked parent in ni_dvp 250 */ 251 int 252 lookup(ndp) 253 register struct nameidata *ndp; 254 { 255 register char *cp; /* pointer into pathname argument */ 256 register struct vnode *dp = 0; /* the directory we are searching */ 257 struct vnode *tdp; /* saved dp */ 258 struct mount *mp; /* mount table entry */ 259 int docache; /* == 0 do not cache last component */ 260 int wantparent; /* 1 => wantparent or lockparent flag */ 261 int rdonly; /* lookup read-only flag bit */ 262 int error = 0; 263 struct componentname *cnp = &ndp->ni_cnd; 264 265 /* 266 * Setup: break out flag bits into variables. 267 */ 268 wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); 269 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; 270 if (cnp->cn_nameiop == DELETE || 271 (wantparent && cnp->cn_nameiop != CREATE)) 272 docache = 0; 273 rdonly = cnp->cn_flags & RDONLY; 274 ndp->ni_dvp = NULL; 275 cnp->cn_flags &= ~ISSYMLINK; 276 dp = ndp->ni_startdir; 277 ndp->ni_startdir = NULLVP; 278 VOP_LOCK(dp); 279 280 dirloop: 281 /* 282 * Search a new directory. 283 * 284 * The cn_hash value is for use by vfs_cache. 285 * The last component of the filename is left accessible via 286 * cnp->cn_nameptr for callers that need the name. Callers needing 287 * the name set the SAVENAME flag. When done, they assume 288 * responsibility for freeing the pathname buffer. 289 */ 290 cnp->cn_consume = 0; 291 cnp->cn_hash = 0; 292 for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) 293 cnp->cn_hash += (unsigned char)*cp; 294 cnp->cn_namelen = cp - cnp->cn_nameptr; 295 if (cnp->cn_namelen > NAME_MAX) { 296 error = ENAMETOOLONG; 297 goto bad; 298 } 299 #ifdef NAMEI_DIAGNOSTIC 300 { char c = *cp; 301 *cp = '\0'; 302 printf("{%s}: ", cnp->cn_nameptr); 303 *cp = c; } 304 #endif 305 ndp->ni_pathlen -= cnp->cn_namelen; 306 ndp->ni_next = cp; 307 cnp->cn_flags |= MAKEENTRY; 308 if (*cp == '\0' && docache == 0) 309 cnp->cn_flags &= ~MAKEENTRY; 310 if (cnp->cn_namelen == 2 && 311 cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') 312 cnp->cn_flags |= ISDOTDOT; 313 else 314 cnp->cn_flags &= ~ISDOTDOT; 315 if (*ndp->ni_next == 0) 316 cnp->cn_flags |= ISLASTCN; 317 else 318 cnp->cn_flags &= ~ISLASTCN; 319 320 321 /* 322 * Check for degenerate name (e.g. / or "") 323 * which is a way of talking about a directory, 324 * e.g. like "/." or ".". 325 */ 326 if (cnp->cn_nameptr[0] == '\0') { 327 if (dp->v_type != VDIR) { 328 error = ENOTDIR; 329 goto bad; 330 } 331 if (cnp->cn_nameiop != LOOKUP) { 332 error = EISDIR; 333 goto bad; 334 } 335 if (wantparent) { 336 ndp->ni_dvp = dp; 337 VREF(dp); 338 } 339 ndp->ni_vp = dp; 340 if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF))) 341 VOP_UNLOCK(dp); 342 if (cnp->cn_flags & SAVESTART) 343 panic("lookup: SAVESTART"); 344 return (0); 345 } 346 347 /* 348 * Handle "..": two special cases. 349 * 1. If at root directory (e.g. after chroot) 350 * or at absolute root directory 351 * then ignore it so can't get out. 352 * 2. If this vnode is the root of a mounted 353 * filesystem, then replace it with the 354 * vnode which was mounted on so we take the 355 * .. in the other file system. 356 */ 357 if (cnp->cn_flags & ISDOTDOT) { 358 for (;;) { 359 if (dp == ndp->ni_rootdir || dp == rootvnode) { 360 ndp->ni_dvp = dp; 361 ndp->ni_vp = dp; 362 VREF(dp); 363 goto nextname; 364 } 365 if ((dp->v_flag & VROOT) == 0 || 366 (cnp->cn_flags & NOCROSSMOUNT)) 367 break; 368 tdp = dp; 369 dp = dp->v_mount->mnt_vnodecovered; 370 vput(tdp); 371 VREF(dp); 372 VOP_LOCK(dp); 373 } 374 } 375 376 /* 377 * We now have a segment name to search for, and a directory to search. 378 */ 379 unionlookup: 380 ndp->ni_dvp = dp; 381 if ((error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp)) != 0) { 382 #ifdef DIAGNOSTIC 383 if (ndp->ni_vp != NULL) 384 panic("leaf should be empty"); 385 #endif 386 #ifdef NAMEI_DIAGNOSTIC 387 printf("not found\n"); 388 #endif 389 if ((error == ENOENT) && 390 (dp->v_flag & VROOT) && 391 (dp->v_mount->mnt_flag & MNT_UNION)) { 392 tdp = dp; 393 dp = dp->v_mount->mnt_vnodecovered; 394 vput(tdp); 395 VREF(dp); 396 VOP_LOCK(dp); 397 goto unionlookup; 398 } 399 400 if (error != EJUSTRETURN) 401 goto bad; 402 /* 403 * If creating and at end of pathname, then can consider 404 * allowing file to be created. 405 */ 406 if (rdonly || (ndp->ni_dvp->v_mount->mnt_flag & MNT_RDONLY)) { 407 error = EROFS; 408 goto bad; 409 } 410 /* 411 * We return with ni_vp NULL to indicate that the entry 412 * doesn't currently exist, leaving a pointer to the 413 * (possibly locked) directory inode in ndp->ni_dvp. 414 */ 415 if (cnp->cn_flags & SAVESTART) { 416 ndp->ni_startdir = ndp->ni_dvp; 417 VREF(ndp->ni_startdir); 418 } 419 return (0); 420 } 421 #ifdef NAMEI_DIAGNOSTIC 422 printf("found\n"); 423 #endif 424 425 /* 426 * Take into account any additional components consumed by 427 * the underlying filesystem. 428 */ 429 if (cnp->cn_consume > 0) { 430 cnp->cn_nameptr += cnp->cn_consume; 431 ndp->ni_next += cnp->cn_consume; 432 ndp->ni_pathlen -= cnp->cn_consume; 433 cnp->cn_consume = 0; 434 } 435 436 dp = ndp->ni_vp; 437 /* 438 * Check to see if the vnode has been mounted on; 439 * if so find the root of the mounted file system. 440 */ 441 while (dp->v_type == VDIR && (mp = dp->v_mountedhere) && 442 (cnp->cn_flags & NOCROSSMOUNT) == 0) { 443 if (mp->mnt_flag & MNT_MLOCK) { 444 mp->mnt_flag |= MNT_MWAIT; 445 sleep((caddr_t)mp, PVFS); 446 continue; 447 } 448 if ((error = VFS_ROOT(dp->v_mountedhere, &tdp)) != 0) 449 goto bad2; 450 vput(dp); 451 ndp->ni_vp = dp = tdp; 452 } 453 454 /* 455 * Check for symbolic link 456 */ 457 if ((dp->v_type == VLNK) && 458 ((cnp->cn_flags & FOLLOW) || *ndp->ni_next == '/')) { 459 cnp->cn_flags |= ISSYMLINK; 460 return (0); 461 } 462 463 nextname: 464 /* 465 * Not a symbolic link. If more pathname, 466 * continue at next component, else return. 467 */ 468 if (*ndp->ni_next == '/') { 469 cnp->cn_nameptr = ndp->ni_next; 470 while (*cnp->cn_nameptr == '/') { 471 cnp->cn_nameptr++; 472 ndp->ni_pathlen--; 473 } 474 vrele(ndp->ni_dvp); 475 goto dirloop; 476 } 477 /* 478 * Check for read-only file systems. 479 */ 480 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 481 /* 482 * Disallow directory write attempts on read-only 483 * file systems. 484 */ 485 if (rdonly || (dp->v_mount->mnt_flag & MNT_RDONLY) || 486 (wantparent && 487 (ndp->ni_dvp->v_mount->mnt_flag & MNT_RDONLY))) { 488 error = EROFS; 489 goto bad2; 490 } 491 } 492 if (cnp->cn_flags & SAVESTART) { 493 ndp->ni_startdir = ndp->ni_dvp; 494 VREF(ndp->ni_startdir); 495 } 496 if (!wantparent) 497 vrele(ndp->ni_dvp); 498 if ((cnp->cn_flags & LOCKLEAF) == 0) 499 VOP_UNLOCK(dp); 500 return (0); 501 502 bad2: 503 if ((cnp->cn_flags & LOCKPARENT) && *ndp->ni_next == '\0') 504 VOP_UNLOCK(ndp->ni_dvp); 505 vrele(ndp->ni_dvp); 506 bad: 507 vput(dp); 508 ndp->ni_vp = NULL; 509 return (error); 510 } 511 512 /* 513 * Reacquire a path name component. 514 */ 515 int 516 relookup(dvp, vpp, cnp) 517 struct vnode *dvp, **vpp; 518 struct componentname *cnp; 519 { 520 register struct vnode *dp = 0; /* the directory we are searching */ 521 int docache; /* == 0 do not cache last component */ 522 int wantparent; /* 1 => wantparent or lockparent flag */ 523 int rdonly; /* lookup read-only flag bit */ 524 int error = 0; 525 #ifdef NAMEI_DIAGNOSTIC 526 int newhash; /* DEBUG: check name hash */ 527 char *cp; /* DEBUG: check name ptr/len */ 528 #endif 529 530 /* 531 * Setup: break out flag bits into variables. 532 */ 533 wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT); 534 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; 535 if (cnp->cn_nameiop == DELETE || 536 (wantparent && cnp->cn_nameiop != CREATE)) 537 docache = 0; 538 rdonly = cnp->cn_flags & RDONLY; 539 cnp->cn_flags &= ~ISSYMLINK; 540 dp = dvp; 541 VOP_LOCK(dp); 542 543 /* dirloop: */ 544 /* 545 * Search a new directory. 546 * 547 * The cn_hash value is for use by vfs_cache. 548 * The last component of the filename is left accessible via 549 * cnp->cn_nameptr for callers that need the name. Callers needing 550 * the name set the SAVENAME flag. When done, they assume 551 * responsibility for freeing the pathname buffer. 552 */ 553 #ifdef NAMEI_DIAGNOSTIC 554 for (newhash = 0, cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) 555 newhash += (unsigned char)*cp; 556 if (newhash != cnp->cn_hash) 557 panic("relookup: bad hash"); 558 if (cnp->cn_namelen != cp - cnp->cn_nameptr) 559 panic ("relookup: bad len"); 560 if (*cp != 0) 561 panic("relookup: not last component"); 562 printf("{%s}: ", cnp->cn_nameptr); 563 #endif 564 565 /* 566 * Check for degenerate name (e.g. / or "") 567 * which is a way of talking about a directory, 568 * e.g. like "/." or ".". 569 */ 570 if (cnp->cn_nameptr[0] == '\0') { 571 if (dp->v_type != VDIR) { 572 error = ENOTDIR; 573 goto bad; 574 } 575 if (cnp->cn_nameiop != LOOKUP || wantparent) { 576 error = EISDIR; 577 goto bad; 578 } 579 if (!(cnp->cn_flags & LOCKLEAF)) 580 VOP_UNLOCK(dp); 581 *vpp = dp; 582 if (cnp->cn_flags & SAVESTART) 583 panic("lookup: SAVESTART"); 584 return (0); 585 } 586 587 if (cnp->cn_flags & ISDOTDOT) 588 panic ("relookup: lookup on dot-dot"); 589 590 /* 591 * We now have a segment name to search for, and a directory to search. 592 */ 593 if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) { 594 #ifdef DIAGNOSTIC 595 if (*vpp != NULL) 596 panic("leaf should be empty"); 597 #endif 598 if (error != EJUSTRETURN) 599 goto bad; 600 /* 601 * If creating and at end of pathname, then can consider 602 * allowing file to be created. 603 */ 604 if (rdonly || (dvp->v_mount->mnt_flag & MNT_RDONLY)) { 605 error = EROFS; 606 goto bad; 607 } 608 /* ASSERT(dvp == ndp->ni_startdir) */ 609 if (cnp->cn_flags & SAVESTART) 610 VREF(dvp); 611 /* 612 * We return with ni_vp NULL to indicate that the entry 613 * doesn't currently exist, leaving a pointer to the 614 * (possibly locked) directory inode in ndp->ni_dvp. 615 */ 616 return (0); 617 } 618 dp = *vpp; 619 620 #ifdef DIAGNOSTIC 621 /* 622 * Check for symbolic link 623 */ 624 if (dp->v_type == VLNK && (cnp->cn_flags & FOLLOW)) 625 panic ("relookup: symlink found.\n"); 626 #endif 627 628 /* 629 * Check for read-only file systems. 630 */ 631 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 632 /* 633 * Disallow directory write attempts on read-only 634 * file systems. 635 */ 636 if (rdonly || (dp->v_mount->mnt_flag & MNT_RDONLY) || 637 (wantparent && 638 (dvp->v_mount->mnt_flag & MNT_RDONLY))) { 639 error = EROFS; 640 goto bad2; 641 } 642 } 643 /* ASSERT(dvp == ndp->ni_startdir) */ 644 if (cnp->cn_flags & SAVESTART) 645 VREF(dvp); 646 647 if (!wantparent) 648 vrele(dvp); 649 if ((cnp->cn_flags & LOCKLEAF) == 0) 650 VOP_UNLOCK(dp); 651 return (0); 652 653 bad2: 654 if ((cnp->cn_flags & LOCKPARENT) && (cnp->cn_flags & ISLASTCN)) 655 VOP_UNLOCK(dvp); 656 vrele(dvp); 657 bad: 658 vput(dp); 659 *vpp = NULL; 660 return (error); 661 } 662
Indexes created Mon Sep 22 13:09:51 GMT 2025