vfs_lookup.c revision 1.14
1 /* $NetBSD: vfs_lookup.c,v 1.14 1994/12/14 19:41:23 mycroft 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/syslimits.h> 45 #include <sys/time.h> 46 #include <sys/namei.h> 47 #include <sys/vnode.h> 48 #include <sys/mount.h> 49 #include <sys/errno.h> 50 #include <sys/malloc.h> 51 #include <sys/filedesc.h> 52 #include <sys/proc.h> 53 54 #ifdef KTRACE 55 #include <sys/ktrace.h> 56 #endif 57 58 /* 59 * Convert a pathname into a pointer to a locked inode. 60 * 61 * The FOLLOW flag is set when symbolic links are to be followed 62 * when they occur at the end of the name translation process. 63 * Symbolic links are always followed for all other pathname 64 * components other than the last. 65 * 66 * The segflg defines whether the name is to be copied from user 67 * space or kernel space. 68 * 69 * Overall outline of namei: 70 * 71 * copy in name 72 * get starting directory 73 * while (!done && !error) { 74 * call lookup to search path. 75 * if symbolic link, massage name in buffer and continue 76 * } 77 */ 78 int 79 namei(ndp) 80 register struct nameidata *ndp; 81 { 82 register struct filedesc *fdp; /* pointer to file descriptor state */ 83 register char *cp; /* pointer into pathname argument */ 84 register struct vnode *dp; /* the directory we are searching */ 85 struct iovec aiov; /* uio for reading symbolic links */ 86 struct uio auio; 87 int error, linklen; 88 struct componentname *cnp = &ndp->ni_cnd; 89 90 ndp->ni_cnd.cn_cred = ndp->ni_cnd.cn_proc->p_ucred; 91 #ifdef DIAGNOSTIC 92 if (!cnp->cn_cred || !cnp->cn_proc) 93 panic ("namei: bad cred/proc"); 94 if (cnp->cn_nameiop & (~OPMASK)) 95 panic ("namei: nameiop contaminated with flags"); 96 if (cnp->cn_flags & OPMASK) 97 panic ("namei: flags contaminated with nameiops"); 98 #endif 99 fdp = cnp->cn_proc->p_fd; 100 101 /* 102 * Get a buffer for the name to be translated, and copy the 103 * name into the buffer. 104 */ 105 if ((cnp->cn_flags & HASBUF) == 0) 106 MALLOC(cnp->cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK); 107 if (ndp->ni_segflg == UIO_SYSSPACE) 108 error = copystr(ndp->ni_dirp, cnp->cn_pnbuf, 109 MAXPATHLEN, &ndp->ni_pathlen); 110 else 111 error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf, 112 MAXPATHLEN, &ndp->ni_pathlen); 113 if (error) { 114 free(cnp->cn_pnbuf, M_NAMEI); 115 ndp->ni_vp = NULL; 116 return (error); 117 } 118 ndp->ni_loopcnt = 0; 119 #ifdef KTRACE 120 if (KTRPOINT(cnp->cn_proc, KTR_NAMEI)) 121 ktrnamei(cnp->cn_proc->p_tracep, cnp->cn_pnbuf); 122 #endif 123 124 /* 125 * Get starting point for the translation. 126 */ 127 if ((ndp->ni_rootdir = fdp->fd_rdir) == NULL) 128 ndp->ni_rootdir = rootvnode; 129 dp = fdp->fd_cdir; 130 VREF(dp); 131 for (;;) { 132 /* 133 * Check if root directory should replace current directory. 134 * Done at start of translation and after symbolic link. 135 */ 136 cnp->cn_nameptr = cnp->cn_pnbuf; 137 if (*(cnp->cn_nameptr) == '/') { 138 vrele(dp); 139 while (*(cnp->cn_nameptr) == '/') { 140 cnp->cn_nameptr++; 141 ndp->ni_pathlen--; 142 } 143 dp = ndp->ni_rootdir; 144 VREF(dp); 145 } 146 ndp->ni_startdir = dp; 147 if (error = lookup(ndp)) { 148 FREE(cnp->cn_pnbuf, M_NAMEI); 149 return (error); 150 } 151 /* 152 * Check for symbolic link 153 */ 154 if ((cnp->cn_flags & ISSYMLINK) == 0) { 155 if ((cnp->cn_flags & (SAVENAME | SAVESTART)) == 0) 156 FREE(cnp->cn_pnbuf, M_NAMEI); 157 else 158 cnp->cn_flags |= HASBUF; 159 return (0); 160 } 161 if ((cnp->cn_flags & LOCKPARENT) && ndp->ni_pathlen == 1) 162 VOP_UNLOCK(ndp->ni_dvp); 163 if (ndp->ni_loopcnt++ >= MAXSYMLINKS) { 164 error = ELOOP; 165 break; 166 } 167 if (ndp->ni_pathlen > 1) 168 MALLOC(cp, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); 169 else 170 cp = cnp->cn_pnbuf; 171 aiov.iov_base = cp; 172 aiov.iov_len = MAXPATHLEN; 173 auio.uio_iov = &aiov; 174 auio.uio_iovcnt = 1; 175 auio.uio_offset = 0; 176 auio.uio_rw = UIO_READ; 177 auio.uio_segflg = UIO_SYSSPACE; 178 auio.uio_procp = (struct proc *)0; 179 auio.uio_resid = MAXPATHLEN; 180 if (error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred)) { 181 if (ndp->ni_pathlen > 1) 182 free(cp, M_NAMEI); 183 break; 184 } 185 linklen = MAXPATHLEN - auio.uio_resid; 186 if (linklen + ndp->ni_pathlen >= MAXPATHLEN) { 187 if (ndp->ni_pathlen > 1) 188 free(cp, M_NAMEI); 189 error = ENAMETOOLONG; 190 break; 191 } 192 if (ndp->ni_pathlen > 1) { 193 bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen); 194 FREE(cnp->cn_pnbuf, M_NAMEI); 195 cnp->cn_pnbuf = cp; 196 } else 197 cnp->cn_pnbuf[linklen] = '\0'; 198 ndp->ni_pathlen += linklen; 199 vput(ndp->ni_vp); 200 dp = ndp->ni_dvp; 201 } 202 FREE(cnp->cn_pnbuf, M_NAMEI); 203 vrele(ndp->ni_dvp); 204 vput(ndp->ni_vp); 205 ndp->ni_vp = NULL; 206 return (error); 207 } 208 209 /* 210 * Search a pathname. 211 * This is a very central and rather complicated routine. 212 * 213 * The pathname is pointed to by ni_ptr and is of length ni_pathlen. 214 * The starting directory is taken from ni_startdir. The pathname is 215 * descended until done, or a symbolic link is encountered. The variable 216 * ni_more is clear if the path is completed; it is set to one if a 217 * symbolic link needing interpretation is encountered. 218 * 219 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on 220 * whether the name is to be looked up, created, renamed, or deleted. 221 * When CREATE, RENAME, or DELETE is specified, information usable in 222 * creating, renaming, or deleting a directory entry may be calculated. 223 * If flag has LOCKPARENT or'ed into it, the parent directory is returned 224 * locked. If flag has WANTPARENT or'ed into it, the parent directory is 225 * returned unlocked. Otherwise the parent directory is not returned. If 226 * the target of the pathname exists and LOCKLEAF is or'ed into the flag 227 * the target is returned locked, otherwise it is returned unlocked. 228 * When creating or renaming and LOCKPARENT is specified, the target may not 229 * be ".". When deleting and LOCKPARENT is specified, the target may be ".". 230 * 231 * Overall outline of lookup: 232 * 233 * dirloop: 234 * identify next component of name at ndp->ni_ptr 235 * handle degenerate case where name is null string 236 * if .. and crossing mount points and on mounted filesys, find parent 237 * call VOP_LOOKUP routine for next component name 238 * directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set 239 * component vnode returned in ni_vp (if it exists), locked. 240 * if result vnode is mounted on and crossing mount points, 241 * find mounted on vnode 242 * if more components of name, do next level at dirloop 243 * return the answer in ni_vp, locked if LOCKLEAF set 244 * if LOCKPARENT set, return locked parent in ni_dvp 245 * if WANTPARENT set, return unlocked parent in ni_dvp 246 */ 247 int 248 lookup(ndp) 249 register struct nameidata *ndp; 250 { 251 register char *cp; /* pointer into pathname argument */ 252 register struct vnode *dp = 0; /* the directory we are searching */ 253 struct vnode *tdp; /* saved dp */ 254 struct mount *mp; /* mount table entry */ 255 int docache; /* == 0 do not cache last component */ 256 int wantparent; /* 1 => wantparent or lockparent flag */ 257 int rdonly; /* lookup read-only flag bit */ 258 int error = 0; 259 struct componentname *cnp = &ndp->ni_cnd; 260 261 /* 262 * Setup: break out flag bits into variables. 263 */ 264 wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); 265 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; 266 if (cnp->cn_nameiop == DELETE || 267 (wantparent && cnp->cn_nameiop != CREATE)) 268 docache = 0; 269 rdonly = cnp->cn_flags & RDONLY; 270 ndp->ni_dvp = NULL; 271 cnp->cn_flags &= ~ISSYMLINK; 272 dp = ndp->ni_startdir; 273 ndp->ni_startdir = NULLVP; 274 VOP_LOCK(dp); 275 276 dirloop: 277 /* 278 * Search a new directory. 279 * 280 * The cn_hash value is for use by vfs_cache. 281 * The last component of the filename is left accessible via 282 * cnp->cn_nameptr for callers that need the name. Callers needing 283 * the name set the SAVENAME flag. When done, they assume 284 * responsibility for freeing the pathname buffer. 285 */ 286 cnp->cn_consume = 0; 287 cnp->cn_hash = 0; 288 for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) 289 cnp->cn_hash += (unsigned char)*cp; 290 cnp->cn_namelen = cp - cnp->cn_nameptr; 291 if (cnp->cn_namelen > NAME_MAX) { 292 error = ENAMETOOLONG; 293 goto bad; 294 } 295 #ifdef NAMEI_DIAGNOSTIC 296 { char c = *cp; 297 *cp = '\0'; 298 printf("{%s}: ", cnp->cn_nameptr); 299 *cp = c; } 300 #endif 301 ndp->ni_pathlen -= cnp->cn_namelen; 302 ndp->ni_next = cp; 303 cnp->cn_flags |= MAKEENTRY; 304 if (*cp == '\0' && docache == 0) 305 cnp->cn_flags &= ~MAKEENTRY; 306 if (cnp->cn_namelen == 2 && 307 cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.') 308 cnp->cn_flags |= ISDOTDOT; 309 else 310 cnp->cn_flags &= ~ISDOTDOT; 311 if (*ndp->ni_next == 0) 312 cnp->cn_flags |= ISLASTCN; 313 else 314 cnp->cn_flags &= ~ISLASTCN; 315 316 317 /* 318 * Check for degenerate name (e.g. / or "") 319 * which is a way of talking about a directory, 320 * e.g. like "/." or ".". 321 */ 322 if (cnp->cn_nameptr[0] == '\0') { 323 if (dp->v_type != VDIR) { 324 error = ENOTDIR; 325 goto bad; 326 } 327 if (cnp->cn_nameiop != LOOKUP) { 328 error = EISDIR; 329 goto bad; 330 } 331 if (wantparent) { 332 ndp->ni_dvp = dp; 333 VREF(dp); 334 } 335 ndp->ni_vp = dp; 336 if (!(cnp->cn_flags & (LOCKPARENT | LOCKLEAF))) 337 VOP_UNLOCK(dp); 338 if (cnp->cn_flags & SAVESTART) 339 panic("lookup: SAVESTART"); 340 return (0); 341 } 342 343 /* 344 * Handle "..": two special cases. 345 * 1. If at root directory (e.g. after chroot) 346 * or at absolute root directory 347 * then ignore it so can't get out. 348 * 2. If this vnode is the root of a mounted 349 * filesystem, then replace it with the 350 * vnode which was mounted on so we take the 351 * .. in the other file system. 352 */ 353 if (cnp->cn_flags & ISDOTDOT) { 354 for (;;) { 355 if (dp == ndp->ni_rootdir || dp == rootvnode) { 356 ndp->ni_dvp = dp; 357 ndp->ni_vp = dp; 358 VREF(dp); 359 goto nextname; 360 } 361 if ((dp->v_flag & VROOT) == 0 || 362 (cnp->cn_flags & NOCROSSMOUNT)) 363 break; 364 tdp = dp; 365 dp = dp->v_mount->mnt_vnodecovered; 366 vput(tdp); 367 VREF(dp); 368 VOP_LOCK(dp); 369 } 370 } 371 372 /* 373 * We now have a segment name to search for, and a directory to search. 374 */ 375 unionlookup: 376 ndp->ni_dvp = dp; 377 if (error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp)) { 378 #ifdef DIAGNOSTIC 379 if (ndp->ni_vp != NULL) 380 panic("leaf should be empty"); 381 #endif 382 #ifdef NAMEI_DIAGNOSTIC 383 printf("not found\n"); 384 #endif 385 if ((error == ENOENT) && 386 (dp->v_flag & VROOT) && 387 (dp->v_mount->mnt_flag & MNT_UNION)) { 388 tdp = dp; 389 dp = dp->v_mount->mnt_vnodecovered; 390 vput(tdp); 391 VREF(dp); 392 VOP_LOCK(dp); 393 goto unionlookup; 394 } 395 396 if (error != EJUSTRETURN) 397 goto bad; 398 /* 399 * If creating and at end of pathname, then can consider 400 * allowing file to be created. 401 */ 402 if (rdonly || (ndp->ni_dvp->v_mount->mnt_flag & MNT_RDONLY)) { 403 error = EROFS; 404 goto bad; 405 } 406 /* 407 * We return with ni_vp NULL to indicate that the entry 408 * doesn't currently exist, leaving a pointer to the 409 * (possibly locked) directory inode in ndp->ni_dvp. 410 */ 411 if (cnp->cn_flags & SAVESTART) { 412 ndp->ni_startdir = ndp->ni_dvp; 413 VREF(ndp->ni_startdir); 414 } 415 return (0); 416 } 417 #ifdef NAMEI_DIAGNOSTIC 418 printf("found\n"); 419 #endif 420 421 /* 422 * Take into account any additional components consumed by 423 * the underlying filesystem. 424 */ 425 if (cnp->cn_consume > 0) { 426 cnp->cn_nameptr += cnp->cn_consume; 427 ndp->ni_next += cnp->cn_consume; 428 ndp->ni_pathlen -= cnp->cn_consume; 429 cnp->cn_consume = 0; 430 } 431 432 dp = ndp->ni_vp; 433 /* 434 * Check to see if the vnode has been mounted on; 435 * if so find the root of the mounted file system. 436 */ 437 while (dp->v_type == VDIR && (mp = dp->v_mountedhere) && 438 (cnp->cn_flags & NOCROSSMOUNT) == 0) { 439 if (mp->mnt_flag & MNT_MLOCK) { 440 mp->mnt_flag |= MNT_MWAIT; 441 sleep((caddr_t)mp, PVFS); 442 continue; 443 } 444 if (error = VFS_ROOT(dp->v_mountedhere, &tdp)) 445 goto bad2; 446 vput(dp); 447 ndp->ni_vp = dp = tdp; 448 } 449 450 /* 451 * Check for symbolic link 452 */ 453 if ((dp->v_type == VLNK) && 454 ((cnp->cn_flags & FOLLOW) || *ndp->ni_next == '/')) { 455 cnp->cn_flags |= ISSYMLINK; 456 return (0); 457 } 458 459 nextname: 460 /* 461 * Not a symbolic link. If more pathname, 462 * continue at next component, else return. 463 */ 464 if (*ndp->ni_next == '/') { 465 cnp->cn_nameptr = ndp->ni_next; 466 while (*cnp->cn_nameptr == '/') { 467 cnp->cn_nameptr++; 468 ndp->ni_pathlen--; 469 } 470 vrele(ndp->ni_dvp); 471 goto dirloop; 472 } 473 /* 474 * Check for read-only file systems. 475 */ 476 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 477 /* 478 * Disallow directory write attempts on read-only 479 * file systems. 480 */ 481 if (rdonly || (dp->v_mount->mnt_flag & MNT_RDONLY) || 482 (wantparent && 483 (ndp->ni_dvp->v_mount->mnt_flag & MNT_RDONLY))) { 484 error = EROFS; 485 goto bad2; 486 } 487 } 488 if (cnp->cn_flags & SAVESTART) { 489 ndp->ni_startdir = ndp->ni_dvp; 490 VREF(ndp->ni_startdir); 491 } 492 if (!wantparent) 493 vrele(ndp->ni_dvp); 494 if ((cnp->cn_flags & LOCKLEAF) == 0) 495 VOP_UNLOCK(dp); 496 return (0); 497 498 bad2: 499 if ((cnp->cn_flags & LOCKPARENT) && *ndp->ni_next == '\0') 500 VOP_UNLOCK(ndp->ni_dvp); 501 vrele(ndp->ni_dvp); 502 bad: 503 vput(dp); 504 ndp->ni_vp = NULL; 505 return (error); 506 } 507 508 /* 509 * Reacquire a path name component. 510 */ 511 int 512 relookup(dvp, vpp, cnp) 513 struct vnode *dvp, **vpp; 514 struct componentname *cnp; 515 { 516 register struct vnode *dp = 0; /* the directory we are searching */ 517 int docache; /* == 0 do not cache last component */ 518 int wantparent; /* 1 => wantparent or lockparent flag */ 519 int rdonly; /* lookup read-only flag bit */ 520 int error = 0; 521 #ifdef NAMEI_DIAGNOSTIC 522 int newhash; /* DEBUG: check name hash */ 523 char *cp; /* DEBUG: check name ptr/len */ 524 #endif 525 526 /* 527 * Setup: break out flag bits into variables. 528 */ 529 wantparent = cnp->cn_flags & (LOCKPARENT|WANTPARENT); 530 docache = (cnp->cn_flags & NOCACHE) ^ NOCACHE; 531 if (cnp->cn_nameiop == DELETE || 532 (wantparent && cnp->cn_nameiop != CREATE)) 533 docache = 0; 534 rdonly = cnp->cn_flags & RDONLY; 535 cnp->cn_flags &= ~ISSYMLINK; 536 dp = dvp; 537 VOP_LOCK(dp); 538 539 /* dirloop: */ 540 /* 541 * Search a new directory. 542 * 543 * The cn_hash value is for use by vfs_cache. 544 * The last component of the filename is left accessible via 545 * cnp->cn_nameptr for callers that need the name. Callers needing 546 * the name set the SAVENAME flag. When done, they assume 547 * responsibility for freeing the pathname buffer. 548 */ 549 #ifdef NAMEI_DIAGNOSTIC 550 for (newhash = 0, cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++) 551 newhash += (unsigned char)*cp; 552 if (newhash != cnp->cn_hash) 553 panic("relookup: bad hash"); 554 if (cnp->cn_namelen != cp - cnp->cn_nameptr) 555 panic ("relookup: bad len"); 556 if (*cp != 0) 557 panic("relookup: not last component"); 558 printf("{%s}: ", cnp->cn_nameptr); 559 #endif 560 561 /* 562 * Check for degenerate name (e.g. / or "") 563 * which is a way of talking about a directory, 564 * e.g. like "/." or ".". 565 */ 566 if (cnp->cn_nameptr[0] == '\0') { 567 if (dp->v_type != VDIR) { 568 error = ENOTDIR; 569 goto bad; 570 } 571 if (cnp->cn_nameiop != LOOKUP || wantparent) { 572 error = EISDIR; 573 goto bad; 574 } 575 if (!(cnp->cn_flags & LOCKLEAF)) 576 VOP_UNLOCK(dp); 577 *vpp = dp; 578 if (cnp->cn_flags & SAVESTART) 579 panic("lookup: SAVESTART"); 580 return (0); 581 } 582 583 if (cnp->cn_flags & ISDOTDOT) 584 panic ("relookup: lookup on dot-dot"); 585 586 /* 587 * We now have a segment name to search for, and a directory to search. 588 */ 589 if (error = VOP_LOOKUP(dp, vpp, cnp)) { 590 #ifdef DIAGNOSTIC 591 if (*vpp != NULL) 592 panic("leaf should be empty"); 593 #endif 594 if (error != EJUSTRETURN) 595 goto bad; 596 /* 597 * If creating and at end of pathname, then can consider 598 * allowing file to be created. 599 */ 600 if (rdonly || (dvp->v_mount->mnt_flag & MNT_RDONLY)) { 601 error = EROFS; 602 goto bad; 603 } 604 /* ASSERT(dvp == ndp->ni_startdir) */ 605 if (cnp->cn_flags & SAVESTART) 606 VREF(dvp); 607 /* 608 * We return with ni_vp NULL to indicate that the entry 609 * doesn't currently exist, leaving a pointer to the 610 * (possibly locked) directory inode in ndp->ni_dvp. 611 */ 612 return (0); 613 } 614 dp = *vpp; 615 616 #ifdef DIAGNOSTIC 617 /* 618 * Check for symbolic link 619 */ 620 if (dp->v_type == VLNK && (cnp->cn_flags & FOLLOW)) 621 panic ("relookup: symlink found.\n"); 622 #endif 623 624 /* 625 * Check for read-only file systems. 626 */ 627 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 628 /* 629 * Disallow directory write attempts on read-only 630 * file systems. 631 */ 632 if (rdonly || (dp->v_mount->mnt_flag & MNT_RDONLY) || 633 (wantparent && 634 (dvp->v_mount->mnt_flag & MNT_RDONLY))) { 635 error = EROFS; 636 goto bad2; 637 } 638 } 639 /* ASSERT(dvp == ndp->ni_startdir) */ 640 if (cnp->cn_flags & SAVESTART) 641 VREF(dvp); 642 643 if (!wantparent) 644 vrele(dvp); 645 if ((cnp->cn_flags & LOCKLEAF) == 0) 646 VOP_UNLOCK(dp); 647 return (0); 648 649 bad2: 650 if ((cnp->cn_flags & LOCKPARENT) && (cnp->cn_flags & ISLASTCN)) 651 VOP_UNLOCK(dvp); 652 vrele(dvp); 653 bad: 654 vput(dp); 655 *vpp = NULL; 656 return (error); 657 } 658
Indexes created Sat Sep 20 22:09:52 GMT 2025