Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mount.c
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1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * Copyright (c) 1999 Michael Smith 39 * All rights reserved. 40 * Copyright (c) 1999 Poul-Henning Kamp 41 * All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 * 64 * $FreeBSD: releng/5.1/sys/kern/vfs_mount.c 113958 2003-04-24 08:16:06Z tjr $ 65 */ 66 67 #include <sys/param.h> 68 #include <sys/conf.h> 69 #include <sys/cons.h> 70 #include <sys/kernel.h> 71 #include <sys/linker.h> 72 #include <sys/mac.h> 73 #include <sys/malloc.h> 74 #include <sys/mount.h> 75 #include <sys/mutex.h> 76 #include <sys/namei.h> 77 #include <sys/proc.h> 78 #include <sys/filedesc.h> 79 #include <sys/reboot.h> 80 #include <sys/sysproto.h> 81 #include <sys/sx.h> 82 #include <sys/sysctl.h> 83 #include <sys/sysent.h> 84 #include <sys/systm.h> 85 #include <sys/vnode.h> 86 87 #include <geom/geom.h> 88 89 #include <machine/stdarg.h> 90 91 #include "opt_rootdevname.h" 92 #include "opt_ddb.h" 93 #include "opt_mac.h" 94 95 #ifdef DDB 96 #include <ddb/ddb.h> 97 #endif 98 99 #define ROOTNAME "root_device" 100 101 static void checkdirs(struct vnode *olddp, struct vnode *newdp); 102 static int vfs_nmount(struct thread *td, int, struct uio *); 103 static int vfs_mountroot_try(char *mountfrom); 104 static int vfs_mountroot_ask(void); 105 static void gets(char *cp); 106 107 static int usermount = 0; /* if 1, non-root can mount fs. */ 108 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, ""); 109 110 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 111 112 /* List of mounted filesystems. */ 113 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 114 115 /* For any iteration/modification of mountlist */ 116 struct mtx mountlist_mtx; 117 118 /* For any iteration/modification of mnt_vnodelist */ 119 struct mtx mntvnode_mtx; 120 121 /* 122 * The vnode of the system's root (/ in the filesystem, without chroot 123 * active.) 124 */ 125 struct vnode *rootvnode; 126 127 /* 128 * The root filesystem is detailed in the kernel environment variable 129 * vfs.root.mountfrom, which is expected to be in the general format 130 * 131 * <vfsname>:[<path>] 132 * vfsname := the name of a VFS known to the kernel and capable 133 * of being mounted as root 134 * path := disk device name or other data used by the filesystem 135 * to locate its physical store 136 */ 137 138 /* 139 * The root specifiers we will try if RB_CDROM is specified. 140 */ 141 static char *cdrom_rootdevnames[] = { 142 "cd9660:cd0a", 143 "cd9660:acd0a", 144 "cd9660:wcd0a", 145 NULL 146 }; 147 148 /* legacy find-root code */ 149 char *rootdevnames[2] = {NULL, NULL}; 150 static int setrootbyname(char *name); 151 dev_t rootdev = NODEV; 152 153 /* 154 * Has to be dynamic as the value of rootdev can change; however, it can't 155 * change after the root is mounted, so a user process can't access this 156 * sysctl until after the value is unchangeable. 157 */ 158 static int 159 sysctl_rootdev(SYSCTL_HANDLER_ARGS) 160 { 161 int error; 162 163 /* _RD prevents this from happening. */ 164 KASSERT(req->newptr == NULL, ("Attempt to change root device name")); 165 166 if (rootdev != NODEV) 167 error = sysctl_handle_string(oidp, rootdev->si_name, 0, req); 168 else 169 error = sysctl_handle_string(oidp, "", 0, req); 170 171 return (error); 172 } 173 174 SYSCTL_PROC(_kern, OID_AUTO, rootdev, CTLTYPE_STRING | CTLFLAG_RD, 175 0, 0, sysctl_rootdev, "A", "Root file system device"); 176 177 /* Remove one mount option. */ 178 static void 179 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 180 { 181 182 TAILQ_REMOVE(opts, opt, link); 183 free(opt->name, M_MOUNT); 184 if (opt->value != NULL) 185 free(opt->value, M_MOUNT); 186 #ifdef INVARIANTS 187 else if (opt->len != 0) 188 panic("%s: mount option with NULL value but length != 0", 189 __func__); 190 #endif 191 free(opt, M_MOUNT); 192 } 193 194 /* Release all resources related to the mount options. */ 195 static void 196 vfs_freeopts(struct vfsoptlist *opts) 197 { 198 struct vfsopt *opt; 199 200 while (!TAILQ_EMPTY(opts)) { 201 opt = TAILQ_FIRST(opts); 202 vfs_freeopt(opts, opt); 203 } 204 free(opts, M_MOUNT); 205 } 206 207 /* 208 * If a mount option is specified several times, 209 * (with or without the "no" prefix) only keep 210 * the last occurence of it. 211 */ 212 static void 213 vfs_sanitizeopts(struct vfsoptlist *opts) 214 { 215 struct vfsopt *opt, *opt2, *tmp; 216 int noopt; 217 218 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 219 if (strncmp(opt->name, "no", 2) == 0) 220 noopt = 1; 221 else 222 noopt = 0; 223 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 224 while (opt2 != NULL) { 225 if (strcmp(opt2->name, opt->name) == 0 || 226 (noopt && strcmp(opt->name + 2, opt2->name) == 0) || 227 (!noopt && strncmp(opt2->name, "no", 2) == 0 && 228 strcmp(opt2->name + 2, opt->name) == 0)) { 229 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 230 vfs_freeopt(opts, opt2); 231 opt2 = tmp; 232 } else { 233 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 234 } 235 } 236 } 237 } 238 239 /* 240 * Build a linked list of mount options from a struct uio. 241 */ 242 static int 243 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 244 { 245 struct vfsoptlist *opts; 246 struct vfsopt *opt; 247 unsigned int i, iovcnt; 248 int error, namelen, optlen; 249 250 iovcnt = auio->uio_iovcnt; 251 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 252 TAILQ_INIT(opts); 253 for (i = 0; i < iovcnt; i += 2) { 254 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 255 namelen = auio->uio_iov[i].iov_len; 256 optlen = auio->uio_iov[i + 1].iov_len; 257 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 258 opt->value = NULL; 259 if (auio->uio_segflg == UIO_SYSSPACE) { 260 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 261 } else { 262 error = copyin(auio->uio_iov[i].iov_base, opt->name, 263 namelen); 264 if (error) 265 goto bad; 266 } 267 opt->len = optlen; 268 if (optlen != 0) { 269 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 270 if (auio->uio_segflg == UIO_SYSSPACE) { 271 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 272 optlen); 273 } else { 274 error = copyin(auio->uio_iov[i + 1].iov_base, 275 opt->value, optlen); 276 if (error) 277 goto bad; 278 } 279 } 280 TAILQ_INSERT_TAIL(opts, opt, link); 281 } 282 vfs_sanitizeopts(opts); 283 *options = opts; 284 return (0); 285 bad: 286 vfs_freeopts(opts); 287 return (error); 288 } 289 290 /* 291 * Merge the old mount options with the new ones passed 292 * in the MNT_UPDATE case. 293 */ 294 static void 295 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 296 { 297 struct vfsopt *opt, *opt2, *new; 298 299 TAILQ_FOREACH(opt, opts, link) { 300 /* 301 * Check that this option hasn't been redefined 302 * nor cancelled with a "no" mount option. 303 */ 304 opt2 = TAILQ_FIRST(toopts); 305 while (opt2 != NULL) { 306 if (strcmp(opt2->name, opt->name) == 0) 307 goto next; 308 if (strncmp(opt2->name, "no", 2) == 0 && 309 strcmp(opt2->name + 2, opt->name) == 0) { 310 vfs_freeopt(toopts, opt2); 311 goto next; 312 } 313 opt2 = TAILQ_NEXT(opt2, link); 314 } 315 /* We want this option, duplicate it. */ 316 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 317 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 318 strcpy(new->name, opt->name); 319 if (opt->len != 0) { 320 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 321 bcopy(opt->value, new->value, opt->len); 322 } else { 323 new->value = NULL; 324 } 325 new->len = opt->len; 326 TAILQ_INSERT_TAIL(toopts, new, link); 327 next: 328 continue; 329 } 330 } 331 332 /* 333 * New mount API. 334 */ 335 int 336 nmount(td, uap) 337 struct thread *td; 338 struct nmount_args /* { 339 struct iovec *iovp; 340 unsigned int iovcnt; 341 int flags; 342 } */ *uap; 343 { 344 struct uio auio; 345 struct iovec *iov, *needfree; 346 struct iovec aiov[UIO_SMALLIOV]; 347 unsigned int i; 348 int error; 349 u_int iovlen, iovcnt; 350 351 iovcnt = uap->iovcnt; 352 iovlen = iovcnt * sizeof (struct iovec); 353 /* 354 * Check that we have an even number of iovec's 355 * and that we have at least two options. 356 */ 357 if ((iovcnt & 1) || (iovcnt < 4) || (iovcnt > UIO_MAXIOV)) 358 return (EINVAL); 359 360 if (iovcnt > UIO_SMALLIOV) { 361 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 362 needfree = iov; 363 } else { 364 iov = aiov; 365 needfree = NULL; 366 } 367 auio.uio_iov = iov; 368 auio.uio_iovcnt = iovcnt; 369 auio.uio_segflg = UIO_USERSPACE; 370 if ((error = copyin(uap->iovp, iov, iovlen))) 371 goto finish; 372 373 for (i = 0; i < iovcnt; i++) { 374 if (iov->iov_len > MMAXOPTIONLEN) { 375 error = EINVAL; 376 goto finish; 377 } 378 iov++; 379 } 380 error = vfs_nmount(td, uap->flags, &auio); 381 finish: 382 if (needfree != NULL) 383 free(needfree, M_TEMP); 384 return (error); 385 } 386 387 int 388 kernel_mount(iovp, iovcnt, flags) 389 struct iovec *iovp; 390 unsigned int iovcnt; 391 int flags; 392 { 393 struct uio auio; 394 int error; 395 396 /* 397 * Check that we have an even number of iovec's 398 * and that we have at least two options. 399 */ 400 if ((iovcnt & 1) || (iovcnt < 4)) 401 return (EINVAL); 402 403 auio.uio_iov = iovp; 404 auio.uio_iovcnt = iovcnt; 405 auio.uio_segflg = UIO_SYSSPACE; 406 407 error = vfs_nmount(curthread, flags, &auio); 408 return (error); 409 } 410 411 int 412 kernel_vmount(int flags, ...) 413 { 414 struct iovec *iovp; 415 struct uio auio; 416 va_list ap; 417 unsigned int iovcnt, iovlen, len; 418 const char *cp; 419 char *buf, *pos; 420 size_t n; 421 int error, i; 422 423 len = 0; 424 va_start(ap, flags); 425 for (iovcnt = 0; (cp = va_arg(ap, const char *)) != NULL; iovcnt++) 426 len += strlen(cp) + 1; 427 va_end(ap); 428 429 if (iovcnt < 4 || iovcnt & 1) 430 return (EINVAL); 431 432 iovlen = iovcnt * sizeof (struct iovec); 433 MALLOC(iovp, struct iovec *, iovlen, M_MOUNT, M_WAITOK); 434 MALLOC(buf, char *, len, M_MOUNT, M_WAITOK); 435 pos = buf; 436 va_start(ap, flags); 437 for (i = 0; i < iovcnt; i++) { 438 cp = va_arg(ap, const char *); 439 copystr(cp, pos, len - (pos - buf), &n); 440 iovp[i].iov_base = pos; 441 iovp[i].iov_len = n; 442 pos += n; 443 } 444 va_end(ap); 445 446 auio.uio_iov = iovp; 447 auio.uio_iovcnt = iovcnt; 448 auio.uio_segflg = UIO_SYSSPACE; 449 450 error = vfs_nmount(curthread, flags, &auio); 451 FREE(iovp, M_MOUNT); 452 FREE(buf, M_MOUNT); 453 return (error); 454 } 455 456 /* 457 * vfs_nmount(): actually attempt a filesystem mount. 458 */ 459 static int 460 vfs_nmount(td, fsflags, fsoptions) 461 struct thread *td; 462 int fsflags; /* Flags common to all filesystems. */ 463 struct uio *fsoptions; /* Options local to the filesystem. */ 464 { 465 linker_file_t lf; 466 struct vnode *vp; 467 struct mount *mp; 468 struct vfsconf *vfsp; 469 struct vfsoptlist *optlist; 470 char *fstype, *fspath; 471 int error, flag = 0, kern_flag = 0; 472 int fstypelen, fspathlen; 473 struct vattr va; 474 struct nameidata nd; 475 476 error = vfs_buildopts(fsoptions, &optlist); 477 if (error) 478 return (error); 479 480 /* 481 * We need these two options before the others, 482 * and they are mandatory for any filesystem. 483 * Ensure they are NUL terminated as well. 484 */ 485 fstypelen = 0; 486 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 487 if (error || fstype[fstypelen - 1] != '\0') { 488 error = EINVAL; 489 goto bad; 490 } 491 fspathlen = 0; 492 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 493 if (error || fspath[fspathlen - 1] != '\0') { 494 error = EINVAL; 495 goto bad; 496 } 497 498 /* 499 * Be ultra-paranoid about making sure the type and fspath 500 * variables will fit in our mp buffers, including the 501 * terminating NUL. 502 */ 503 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 504 error = ENAMETOOLONG; 505 goto bad; 506 } 507 508 if (usermount == 0) { 509 error = suser(td); 510 if (error) 511 goto bad; 512 } 513 /* 514 * Do not allow NFS export by non-root users. 515 */ 516 if (fsflags & MNT_EXPORTED) { 517 error = suser(td); 518 if (error) 519 goto bad; 520 } 521 /* 522 * Silently enforce MNT_NOSUID and MNT_NODEV for non-root users. 523 */ 524 if (suser(td)) 525 fsflags |= MNT_NOSUID | MNT_NODEV; 526 /* 527 * Get vnode to be covered 528 */ 529 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 530 if ((error = namei(&nd)) != 0) 531 goto bad; 532 NDFREE(&nd, NDF_ONLY_PNBUF); 533 vp = nd.ni_vp; 534 if (fsflags & MNT_UPDATE) { 535 if ((vp->v_vflag & VV_ROOT) == 0) { 536 vput(vp); 537 error = EINVAL; 538 goto bad; 539 } 540 mp = vp->v_mount; 541 flag = mp->mnt_flag; 542 kern_flag = mp->mnt_kern_flag; 543 /* 544 * We only allow the filesystem to be reloaded if it 545 * is currently mounted read-only. 546 */ 547 if ((fsflags & MNT_RELOAD) && 548 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 549 vput(vp); 550 error = EOPNOTSUPP; /* Needs translation */ 551 goto bad; 552 } 553 /* 554 * Only root, or the user that did the original mount is 555 * permitted to update it. 556 */ 557 if (mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 558 error = suser(td); 559 if (error) { 560 vput(vp); 561 goto bad; 562 } 563 } 564 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 565 vput(vp); 566 error = EBUSY; 567 goto bad; 568 } 569 VI_LOCK(vp); 570 if ((vp->v_iflag & VI_MOUNT) != 0 || 571 vp->v_mountedhere != NULL) { 572 VI_UNLOCK(vp); 573 vfs_unbusy(mp, td); 574 vput(vp); 575 error = EBUSY; 576 goto bad; 577 } 578 vp->v_iflag |= VI_MOUNT; 579 VI_UNLOCK(vp); 580 mp->mnt_flag |= fsflags & 581 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT); 582 VOP_UNLOCK(vp, 0, td); 583 mp->mnt_optnew = optlist; 584 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 585 goto update; 586 } 587 /* 588 * If the user is not root, ensure that they own the directory 589 * onto which we are attempting to mount. 590 */ 591 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 592 if (error) { 593 vput(vp); 594 goto bad; 595 } 596 if (va.va_uid != td->td_ucred->cr_uid) { 597 error = suser(td); 598 if (error) { 599 vput(vp); 600 goto bad; 601 } 602 } 603 if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) { 604 vput(vp); 605 goto bad; 606 } 607 if (vp->v_type != VDIR) { 608 vput(vp); 609 error = ENOTDIR; 610 goto bad; 611 } 612 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 613 if (!strcmp(vfsp->vfc_name, fstype)) 614 break; 615 if (vfsp == NULL) { 616 /* Only load modules for root (very important!). */ 617 error = suser(td); 618 if (error) { 619 vput(vp); 620 goto bad; 621 } 622 error = securelevel_gt(td->td_ucred, 0); 623 if (error) { 624 vput(vp); 625 goto bad; 626 } 627 error = linker_load_module(NULL, fstype, NULL, NULL, &lf); 628 if (error || lf == NULL) { 629 vput(vp); 630 if (lf == NULL) 631 error = ENODEV; 632 goto bad; 633 } 634 lf->userrefs++; 635 /* Look up again to see if the VFS was loaded. */ 636 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 637 if (!strcmp(vfsp->vfc_name, fstype)) 638 break; 639 if (vfsp == NULL) { 640 lf->userrefs--; 641 linker_file_unload(lf); 642 vput(vp); 643 error = ENODEV; 644 goto bad; 645 } 646 } 647 VI_LOCK(vp); 648 if ((vp->v_iflag & VI_MOUNT) != 0 || 649 vp->v_mountedhere != NULL) { 650 VI_UNLOCK(vp); 651 vput(vp); 652 error = EBUSY; 653 goto bad; 654 } 655 vp->v_iflag |= VI_MOUNT; 656 VI_UNLOCK(vp); 657 658 /* 659 * Allocate and initialize the filesystem. 660 */ 661 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 662 TAILQ_INIT(&mp->mnt_nvnodelist); 663 TAILQ_INIT(&mp->mnt_reservedvnlist); 664 mp->mnt_nvnodelistsize = 0; 665 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 666 (void)vfs_busy(mp, LK_NOWAIT, 0, td); 667 mp->mnt_op = vfsp->vfc_vfsops; 668 mp->mnt_vfc = vfsp; 669 vfsp->vfc_refcount++; 670 mp->mnt_stat.f_type = vfsp->vfc_typenum; 671 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 672 strlcpy(mp->mnt_stat.f_fstypename, fstype, MFSNAMELEN); 673 mp->mnt_vnodecovered = vp; 674 mp->mnt_cred = crdup(td->td_ucred); 675 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 676 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 677 mp->mnt_iosize_max = DFLTPHYS; 678 #ifdef MAC 679 mac_init_mount(mp); 680 mac_create_mount(td->td_ucred, mp); 681 #endif 682 VOP_UNLOCK(vp, 0, td); 683 mp->mnt_optnew = optlist; /* XXXMAC: should this be above? */ 684 685 update: 686 /* 687 * Check if the fs implements the new VFS_NMOUNT() 688 * function, since the new system call was used. 689 */ 690 if (mp->mnt_op->vfs_mount != NULL) { 691 printf("%s doesn't support the new mount syscall\n", 692 mp->mnt_vfc->vfc_name); 693 VI_LOCK(vp); 694 vp->v_iflag &= ~VI_MOUNT; 695 VI_UNLOCK(vp); 696 if (mp->mnt_flag & MNT_UPDATE) 697 vfs_unbusy(mp, td); 698 else { 699 mp->mnt_vfc->vfc_refcount--; 700 vfs_unbusy(mp, td); 701 #ifdef MAC 702 mac_destroy_mount(mp); 703 #endif 704 crfree(mp->mnt_cred); 705 free(mp, M_MOUNT); 706 } 707 vrele(vp); 708 error = EOPNOTSUPP; 709 goto bad; 710 } 711 712 /* 713 * Set the mount level flags. 714 */ 715 if (fsflags & MNT_RDONLY) 716 mp->mnt_flag |= MNT_RDONLY; 717 else if (mp->mnt_flag & MNT_RDONLY) 718 mp->mnt_kern_flag |= MNTK_WANTRDWR; 719 mp->mnt_flag &=~ MNT_UPDATEMASK; 720 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE); 721 /* 722 * Mount the filesystem. 723 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 724 * get. No freeing of cn_pnbuf. 725 */ 726 error = VFS_NMOUNT(mp, &nd, td); 727 if (!error) { 728 if (mp->mnt_opt != NULL) 729 vfs_freeopts(mp->mnt_opt); 730 mp->mnt_opt = mp->mnt_optnew; 731 } 732 /* 733 * Prevent external consumers of mount 734 * options to read mnt_optnew. 735 */ 736 mp->mnt_optnew = NULL; 737 if (mp->mnt_flag & MNT_UPDATE) { 738 if (mp->mnt_kern_flag & MNTK_WANTRDWR) 739 mp->mnt_flag &= ~MNT_RDONLY; 740 mp->mnt_flag &=~ 741 (MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 742 mp->mnt_kern_flag &=~ MNTK_WANTRDWR; 743 if (error) { 744 mp->mnt_flag = flag; 745 mp->mnt_kern_flag = kern_flag; 746 } 747 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 748 if (mp->mnt_syncer == NULL) 749 error = vfs_allocate_syncvnode(mp); 750 } else { 751 if (mp->mnt_syncer != NULL) 752 vrele(mp->mnt_syncer); 753 mp->mnt_syncer = NULL; 754 } 755 vfs_unbusy(mp, td); 756 VI_LOCK(vp); 757 vp->v_iflag &= ~VI_MOUNT; 758 VI_UNLOCK(vp); 759 vrele(vp); 760 return (error); 761 } 762 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 763 /* 764 * Put the new filesystem on the mount list after root. 765 */ 766 cache_purge(vp); 767 if (!error) { 768 struct vnode *newdp; 769 770 VI_LOCK(vp); 771 vp->v_iflag &= ~VI_MOUNT; 772 VI_UNLOCK(vp); 773 vp->v_mountedhere = mp; 774 mtx_lock(&mountlist_mtx); 775 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 776 mtx_unlock(&mountlist_mtx); 777 if (VFS_ROOT(mp, &newdp)) 778 panic("mount: lost mount"); 779 checkdirs(vp, newdp); 780 vput(newdp); 781 VOP_UNLOCK(vp, 0, td); 782 if ((mp->mnt_flag & MNT_RDONLY) == 0) 783 error = vfs_allocate_syncvnode(mp); 784 vfs_unbusy(mp, td); 785 if ((error = VFS_START(mp, 0, td)) != 0) { 786 vrele(vp); 787 goto bad; 788 } 789 } else { 790 VI_LOCK(vp); 791 vp->v_iflag &= ~VI_MOUNT; 792 VI_UNLOCK(vp); 793 mp->mnt_vfc->vfc_refcount--; 794 vfs_unbusy(mp, td); 795 #ifdef MAC 796 mac_destroy_mount(mp); 797 #endif 798 crfree(mp->mnt_cred); 799 free(mp, M_MOUNT); 800 vput(vp); 801 goto bad; 802 } 803 return (0); 804 bad: 805 vfs_freeopts(optlist); 806 return (error); 807 } 808 809 /* 810 * Old mount API. 811 */ 812 #ifndef _SYS_SYSPROTO_H_ 813 struct mount_args { 814 char *type; 815 char *path; 816 int flags; 817 caddr_t data; 818 }; 819 #endif 820 /* ARGSUSED */ 821 int 822 mount(td, uap) 823 struct thread *td; 824 struct mount_args /* { 825 char *type; 826 char *path; 827 int flags; 828 caddr_t data; 829 } */ *uap; 830 { 831 char *fstype; 832 char *fspath; 833 int error; 834 835 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 836 fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK); 837 838 /* 839 * vfs_mount() actually takes a kernel string for `type' and 840 * `path' now, so extract them. 841 */ 842 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 843 if (error == 0) 844 error = copyinstr(uap->path, fspath, MNAMELEN, NULL); 845 if (error == 0) 846 error = vfs_mount(td, fstype, fspath, uap->flags, uap->data); 847 free(fstype, M_TEMP); 848 free(fspath, M_TEMP); 849 return (error); 850 } 851 852 /* 853 * vfs_mount(): actually attempt a filesystem mount. 854 * 855 * This routine is designed to be a "generic" entry point for routines 856 * that wish to mount a filesystem. All parameters except `fsdata' are 857 * pointers into kernel space. `fsdata' is currently still a pointer 858 * into userspace. 859 */ 860 int 861 vfs_mount(td, fstype, fspath, fsflags, fsdata) 862 struct thread *td; 863 const char *fstype; 864 char *fspath; 865 int fsflags; 866 void *fsdata; 867 { 868 linker_file_t lf; 869 struct vnode *vp; 870 struct mount *mp; 871 struct vfsconf *vfsp; 872 int error, flag = 0, kern_flag = 0; 873 struct vattr va; 874 struct nameidata nd; 875 876 /* 877 * Be ultra-paranoid about making sure the type and fspath 878 * variables will fit in our mp buffers, including the 879 * terminating NUL. 880 */ 881 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 882 return (ENAMETOOLONG); 883 884 if (usermount == 0) { 885 error = suser(td); 886 if (error) 887 return (error); 888 } 889 /* 890 * Do not allow NFS export by non-root users. 891 */ 892 if (fsflags & MNT_EXPORTED) { 893 error = suser(td); 894 if (error) 895 return (error); 896 } 897 /* 898 * Silently enforce MNT_NOSUID and MNT_NODEV for non-root users. 899 */ 900 if (suser(td)) 901 fsflags |= MNT_NOSUID | MNT_NODEV; 902 /* 903 * Get vnode to be covered 904 */ 905 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 906 if ((error = namei(&nd)) != 0) 907 return (error); 908 NDFREE(&nd, NDF_ONLY_PNBUF); 909 vp = nd.ni_vp; 910 if (fsflags & MNT_UPDATE) { 911 if ((vp->v_vflag & VV_ROOT) == 0) { 912 vput(vp); 913 return (EINVAL); 914 } 915 mp = vp->v_mount; 916 flag = mp->mnt_flag; 917 kern_flag = mp->mnt_kern_flag; 918 /* 919 * We only allow the filesystem to be reloaded if it 920 * is currently mounted read-only. 921 */ 922 if ((fsflags & MNT_RELOAD) && 923 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 924 vput(vp); 925 return (EOPNOTSUPP); /* Needs translation */ 926 } 927 /* 928 * Only root, or the user that did the original mount is 929 * permitted to update it. 930 */ 931 if (mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 932 error = suser(td); 933 if (error) { 934 vput(vp); 935 return (error); 936 } 937 } 938 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 939 vput(vp); 940 return (EBUSY); 941 } 942 VI_LOCK(vp); 943 if ((vp->v_iflag & VI_MOUNT) != 0 || 944 vp->v_mountedhere != NULL) { 945 VI_UNLOCK(vp); 946 vfs_unbusy(mp, td); 947 vput(vp); 948 return (EBUSY); 949 } 950 vp->v_iflag |= VI_MOUNT; 951 VI_UNLOCK(vp); 952 mp->mnt_flag |= fsflags & 953 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT); 954 VOP_UNLOCK(vp, 0, td); 955 goto update; 956 } 957 /* 958 * If the user is not root, ensure that they own the directory 959 * onto which we are attempting to mount. 960 */ 961 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 962 if (error) { 963 vput(vp); 964 return (error); 965 } 966 if (va.va_uid != td->td_ucred->cr_uid) { 967 error = suser(td); 968 if (error) { 969 vput(vp); 970 return (error); 971 } 972 } 973 if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) { 974 vput(vp); 975 return (error); 976 } 977 if (vp->v_type != VDIR) { 978 vput(vp); 979 return (ENOTDIR); 980 } 981 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 982 if (!strcmp(vfsp->vfc_name, fstype)) 983 break; 984 if (vfsp == NULL) { 985 /* Only load modules for root (very important!). */ 986 error = suser(td); 987 if (error) { 988 vput(vp); 989 return (error); 990 } 991 error = securelevel_gt(td->td_ucred, 0); 992 if (error) { 993 vput(vp); 994 return (error); 995 } 996 error = linker_load_module(NULL, fstype, NULL, NULL, &lf); 997 if (error || lf == NULL) { 998 vput(vp); 999 if (lf == NULL) 1000 error = ENODEV; 1001 return (error); 1002 } 1003 lf->userrefs++; 1004 /* Look up again to see if the VFS was loaded. */ 1005 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 1006 if (!strcmp(vfsp->vfc_name, fstype)) 1007 break; 1008 if (vfsp == NULL) { 1009 lf->userrefs--; 1010 linker_file_unload(lf); 1011 vput(vp); 1012 return (ENODEV); 1013 } 1014 } 1015 VI_LOCK(vp); 1016 if ((vp->v_iflag & VI_MOUNT) != 0 || 1017 vp->v_mountedhere != NULL) { 1018 VI_UNLOCK(vp); 1019 vput(vp); 1020 return (EBUSY); 1021 } 1022 vp->v_iflag |= VI_MOUNT; 1023 VI_UNLOCK(vp); 1024 1025 /* 1026 * Allocate and initialize the filesystem. 1027 */ 1028 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 1029 TAILQ_INIT(&mp->mnt_nvnodelist); 1030 TAILQ_INIT(&mp->mnt_reservedvnlist); 1031 mp->mnt_nvnodelistsize = 0; 1032 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 1033 (void)vfs_busy(mp, LK_NOWAIT, 0, td); 1034 mp->mnt_op = vfsp->vfc_vfsops; 1035 mp->mnt_vfc = vfsp; 1036 vfsp->vfc_refcount++; 1037 mp->mnt_stat.f_type = vfsp->vfc_typenum; 1038 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 1039 strlcpy(mp->mnt_stat.f_fstypename, fstype, MFSNAMELEN); 1040 mp->mnt_vnodecovered = vp; 1041 mp->mnt_cred = crdup(td->td_ucred); 1042 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 1043 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 1044 mp->mnt_iosize_max = DFLTPHYS; 1045 #ifdef MAC 1046 mac_init_mount(mp); 1047 mac_create_mount(td->td_ucred, mp); 1048 #endif 1049 VOP_UNLOCK(vp, 0, td); 1050 update: 1051 /* 1052 * Check if the fs implements the old VFS_MOUNT() 1053 * function, since the old system call was used. 1054 */ 1055 if (mp->mnt_op->vfs_mount == NULL) { 1056 printf("%s doesn't support the old mount syscall\n", 1057 mp->mnt_vfc->vfc_name); 1058 VI_LOCK(vp); 1059 vp->v_iflag &= ~VI_MOUNT; 1060 VI_UNLOCK(vp); 1061 if (mp->mnt_flag & MNT_UPDATE) 1062 vfs_unbusy(mp, td); 1063 else { 1064 mp->mnt_vfc->vfc_refcount--; 1065 vfs_unbusy(mp, td); 1066 #ifdef MAC 1067 mac_destroy_mount(mp); 1068 #endif 1069 crfree(mp->mnt_cred); 1070 free(mp, M_MOUNT); 1071 } 1072 vrele(vp); 1073 return (EOPNOTSUPP); 1074 } 1075 1076 /* 1077 * Set the mount level flags. 1078 */ 1079 if (fsflags & MNT_RDONLY) 1080 mp->mnt_flag |= MNT_RDONLY; 1081 else if (mp->mnt_flag & MNT_RDONLY) 1082 mp->mnt_kern_flag |= MNTK_WANTRDWR; 1083 mp->mnt_flag &=~ MNT_UPDATEMASK; 1084 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE); 1085 /* 1086 * Mount the filesystem. 1087 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1088 * get. No freeing of cn_pnbuf. 1089 */ 1090 error = VFS_MOUNT(mp, fspath, fsdata, &nd, td); 1091 if (mp->mnt_flag & MNT_UPDATE) { 1092 if (mp->mnt_kern_flag & MNTK_WANTRDWR) 1093 mp->mnt_flag &= ~MNT_RDONLY; 1094 mp->mnt_flag &=~ 1095 (MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 1096 mp->mnt_kern_flag &=~ MNTK_WANTRDWR; 1097 if (error) { 1098 mp->mnt_flag = flag; 1099 mp->mnt_kern_flag = kern_flag; 1100 } 1101 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1102 if (mp->mnt_syncer == NULL) 1103 error = vfs_allocate_syncvnode(mp); 1104 } else { 1105 if (mp->mnt_syncer != NULL) 1106 vrele(mp->mnt_syncer); 1107 mp->mnt_syncer = NULL; 1108 } 1109 vfs_unbusy(mp, td); 1110 VI_LOCK(vp); 1111 vp->v_iflag &= ~VI_MOUNT; 1112 VI_UNLOCK(vp); 1113 vrele(vp); 1114 return (error); 1115 } 1116 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1117 /* 1118 * Put the new filesystem on the mount list after root. 1119 */ 1120 cache_purge(vp); 1121 if (!error) { 1122 struct vnode *newdp; 1123 1124 VI_LOCK(vp); 1125 vp->v_iflag &= ~VI_MOUNT; 1126 VI_UNLOCK(vp); 1127 vp->v_mountedhere = mp; 1128 mtx_lock(&mountlist_mtx); 1129 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1130 mtx_unlock(&mountlist_mtx); 1131 if (VFS_ROOT(mp, &newdp)) 1132 panic("mount: lost mount"); 1133 checkdirs(vp, newdp); 1134 vput(newdp); 1135 VOP_UNLOCK(vp, 0, td); 1136 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1137 error = vfs_allocate_syncvnode(mp); 1138 vfs_unbusy(mp, td); 1139 if ((error = VFS_START(mp, 0, td)) != 0) 1140 vrele(vp); 1141 } else { 1142 VI_LOCK(vp); 1143 vp->v_iflag &= ~VI_MOUNT; 1144 VI_UNLOCK(vp); 1145 mp->mnt_vfc->vfc_refcount--; 1146 vfs_unbusy(mp, td); 1147 #ifdef MAC 1148 mac_destroy_mount(mp); 1149 #endif 1150 crfree(mp->mnt_cred); 1151 free(mp, M_MOUNT); 1152 vput(vp); 1153 } 1154 return (error); 1155 } 1156 1157 /* 1158 * Scan all active processes to see if any of them have a current 1159 * or root directory of `olddp'. If so, replace them with the new 1160 * mount point. 1161 */ 1162 static void 1163 checkdirs(olddp, newdp) 1164 struct vnode *olddp, *newdp; 1165 { 1166 struct filedesc *fdp; 1167 struct proc *p; 1168 int nrele; 1169 1170 if (vrefcnt(olddp) == 1) 1171 return; 1172 sx_slock(&allproc_lock); 1173 LIST_FOREACH(p, &allproc, p_list) { 1174 mtx_lock(&fdesc_mtx); 1175 fdp = p->p_fd; 1176 if (fdp == NULL) { 1177 mtx_unlock(&fdesc_mtx); 1178 continue; 1179 } 1180 nrele = 0; 1181 FILEDESC_LOCK(fdp); 1182 if (fdp->fd_cdir == olddp) { 1183 VREF(newdp); 1184 fdp->fd_cdir = newdp; 1185 nrele++; 1186 } 1187 if (fdp->fd_rdir == olddp) { 1188 VREF(newdp); 1189 fdp->fd_rdir = newdp; 1190 nrele++; 1191 } 1192 FILEDESC_UNLOCK(fdp); 1193 mtx_unlock(&fdesc_mtx); 1194 while (nrele--) 1195 vrele(olddp); 1196 } 1197 sx_sunlock(&allproc_lock); 1198 if (rootvnode == olddp) { 1199 vrele(rootvnode); 1200 VREF(newdp); 1201 rootvnode = newdp; 1202 } 1203 } 1204 1205 /* 1206 * Unmount a filesystem. 1207 * 1208 * Note: unmount takes a path to the vnode mounted on as argument, 1209 * not special file (as before). 1210 */ 1211 #ifndef _SYS_SYSPROTO_H_ 1212 struct unmount_args { 1213 char *path; 1214 int flags; 1215 }; 1216 #endif 1217 /* ARGSUSED */ 1218 int 1219 unmount(td, uap) 1220 struct thread *td; 1221 register struct unmount_args /* { 1222 char *path; 1223 int flags; 1224 } */ *uap; 1225 { 1226 register struct vnode *vp; 1227 struct mount *mp; 1228 int error; 1229 struct nameidata nd; 1230 1231 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, uap->path, td); 1232 if ((error = namei(&nd)) != 0) 1233 return (error); 1234 vp = nd.ni_vp; 1235 NDFREE(&nd, NDF_ONLY_PNBUF); 1236 mp = vp->v_mount; 1237 1238 /* 1239 * Only root, or the user that did the original mount is 1240 * permitted to unmount this filesystem. 1241 */ 1242 if (mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) { 1243 error = suser(td); 1244 if (error) { 1245 vput(vp); 1246 return (error); 1247 } 1248 } 1249 1250 /* 1251 * Don't allow unmounting the root filesystem. 1252 */ 1253 if (mp->mnt_flag & MNT_ROOTFS) { 1254 vput(vp); 1255 return (EINVAL); 1256 } 1257 1258 /* 1259 * Must be the root of the filesystem 1260 */ 1261 if ((vp->v_vflag & VV_ROOT) == 0) { 1262 vput(vp); 1263 return (EINVAL); 1264 } 1265 vput(vp); 1266 return (dounmount(mp, uap->flags, td)); 1267 } 1268 1269 /* 1270 * Do the actual filesystem unmount. 1271 */ 1272 int 1273 dounmount(mp, flags, td) 1274 struct mount *mp; 1275 int flags; 1276 struct thread *td; 1277 { 1278 struct vnode *coveredvp, *fsrootvp; 1279 int error; 1280 int async_flag; 1281 1282 mtx_lock(&mountlist_mtx); 1283 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1284 mtx_unlock(&mountlist_mtx); 1285 return (EBUSY); 1286 } 1287 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1288 /* Allow filesystems to detect that a forced unmount is in progress. */ 1289 if (flags & MNT_FORCE) 1290 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1291 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1292 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); 1293 if (error) { 1294 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1295 if (mp->mnt_kern_flag & MNTK_MWAIT) 1296 wakeup(mp); 1297 return (error); 1298 } 1299 vn_start_write(NULL, &mp, V_WAIT); 1300 1301 if (mp->mnt_flag & MNT_EXPUBLIC) 1302 vfs_setpublicfs(NULL, NULL, NULL); 1303 1304 vfs_msync(mp, MNT_WAIT); 1305 async_flag = mp->mnt_flag & MNT_ASYNC; 1306 mp->mnt_flag &=~ MNT_ASYNC; 1307 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1308 if (mp->mnt_syncer != NULL) 1309 vrele(mp->mnt_syncer); 1310 /* Move process cdir/rdir refs on fs root to underlying vnode. */ 1311 if (VFS_ROOT(mp, &fsrootvp) == 0) { 1312 if (mp->mnt_vnodecovered != NULL) 1313 checkdirs(fsrootvp, mp->mnt_vnodecovered); 1314 if (fsrootvp == rootvnode) { 1315 vrele(rootvnode); 1316 rootvnode = NULL; 1317 } 1318 vput(fsrootvp); 1319 } 1320 if (((mp->mnt_flag & MNT_RDONLY) || 1321 (error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) == 0) || 1322 (flags & MNT_FORCE)) { 1323 error = VFS_UNMOUNT(mp, flags, td); 1324 } 1325 vn_finished_write(mp); 1326 if (error) { 1327 /* Undo cdir/rdir and rootvnode changes made above. */ 1328 if (VFS_ROOT(mp, &fsrootvp) == 0) { 1329 if (mp->mnt_vnodecovered != NULL) 1330 checkdirs(mp->mnt_vnodecovered, fsrootvp); 1331 if (rootvnode == NULL) { 1332 rootvnode = fsrootvp; 1333 vref(rootvnode); 1334 } 1335 vput(fsrootvp); 1336 } 1337 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1338 (void) vfs_allocate_syncvnode(mp); 1339 mtx_lock(&mountlist_mtx); 1340 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1341 mp->mnt_flag |= async_flag; 1342 lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, 1343 &mountlist_mtx, td); 1344 if (mp->mnt_kern_flag & MNTK_MWAIT) 1345 wakeup(mp); 1346 return (error); 1347 } 1348 crfree(mp->mnt_cred); 1349 mtx_lock(&mountlist_mtx); 1350 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1351 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 1352 coveredvp->v_mountedhere = NULL; 1353 mp->mnt_vfc->vfc_refcount--; 1354 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 1355 panic("unmount: dangling vnode"); 1356 lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, &mountlist_mtx, td); 1357 lockdestroy(&mp->mnt_lock); 1358 if (coveredvp != NULL) 1359 vrele(coveredvp); 1360 if (mp->mnt_kern_flag & MNTK_MWAIT) 1361 wakeup(mp); 1362 #ifdef MAC 1363 mac_destroy_mount(mp); 1364 #endif 1365 if (mp->mnt_op->vfs_mount == NULL) 1366 vfs_freeopts(mp->mnt_opt); 1367 free(mp, M_MOUNT); 1368 return (0); 1369 } 1370 1371 /* 1372 * Lookup a filesystem type, and if found allocate and initialize 1373 * a mount structure for it. 1374 * 1375 * Devname is usually updated by mount(8) after booting. 1376 */ 1377 int 1378 vfs_rootmountalloc(fstypename, devname, mpp) 1379 char *fstypename; 1380 char *devname; 1381 struct mount **mpp; 1382 { 1383 struct thread *td = curthread; /* XXX */ 1384 struct vfsconf *vfsp; 1385 struct mount *mp; 1386 1387 if (fstypename == NULL) 1388 return (ENODEV); 1389 for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) 1390 if (!strcmp(vfsp->vfc_name, fstypename)) 1391 break; 1392 if (vfsp == NULL) 1393 return (ENODEV); 1394 mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 1395 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 1396 (void)vfs_busy(mp, LK_NOWAIT, 0, td); 1397 TAILQ_INIT(&mp->mnt_nvnodelist); 1398 TAILQ_INIT(&mp->mnt_reservedvnlist); 1399 mp->mnt_nvnodelistsize = 0; 1400 mp->mnt_vfc = vfsp; 1401 mp->mnt_op = vfsp->vfc_vfsops; 1402 mp->mnt_flag = MNT_RDONLY; 1403 mp->mnt_vnodecovered = NULLVP; 1404 mp->mnt_cred = crdup(td->td_ucred); 1405 vfsp->vfc_refcount++; 1406 mp->mnt_iosize_max = DFLTPHYS; 1407 mp->mnt_stat.f_type = vfsp->vfc_typenum; 1408 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 1409 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 1410 mp->mnt_stat.f_mntonname[0] = '/'; 1411 mp->mnt_stat.f_mntonname[1] = 0; 1412 strlcpy(mp->mnt_stat.f_mntfromname, devname, MNAMELEN); 1413 #ifdef MAC 1414 mac_init_mount(mp); 1415 mac_create_mount(td->td_ucred, mp); 1416 #endif 1417 *mpp = mp; 1418 return (0); 1419 } 1420 1421 /* 1422 * Find and mount the root filesystem 1423 */ 1424 void 1425 vfs_mountroot(void) 1426 { 1427 char *cp; 1428 int i, error; 1429 1430 g_waitidle(); 1431 1432 /* 1433 * The root filesystem information is compiled in, and we are 1434 * booted with instructions to use it. 1435 */ 1436 #ifdef ROOTDEVNAME 1437 if ((boothowto & RB_DFLTROOT) && 1438 !vfs_mountroot_try(ROOTDEVNAME)) 1439 return; 1440 #endif 1441 /* 1442 * We are booted with instructions to prompt for the root filesystem, 1443 * or to use the compiled-in default when it doesn't exist. 1444 */ 1445 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 1446 if (!vfs_mountroot_ask()) 1447 return; 1448 } 1449 1450 /* 1451 * We've been given the generic "use CDROM as root" flag. This is 1452 * necessary because one media may be used in many different 1453 * devices, so we need to search for them. 1454 */ 1455 if (boothowto & RB_CDROM) { 1456 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1457 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1458 return; 1459 } 1460 } 1461 1462 /* 1463 * Try to use the value read by the loader from /etc/fstab, or 1464 * supplied via some other means. This is the preferred 1465 * mechanism. 1466 */ 1467 if ((cp = getenv("vfs.root.mountfrom")) != NULL) { 1468 error = vfs_mountroot_try(cp); 1469 freeenv(cp); 1470 if (!error) 1471 return; 1472 } 1473 1474 /* 1475 * Try values that may have been computed by the machine-dependant 1476 * legacy code. 1477 */ 1478 if (!vfs_mountroot_try(rootdevnames[0])) 1479 return; 1480 if (!vfs_mountroot_try(rootdevnames[1])) 1481 return; 1482 1483 /* 1484 * If we have a compiled-in default, and haven't already tried it, try 1485 * it now. 1486 */ 1487 #ifdef ROOTDEVNAME 1488 if (!(boothowto & RB_DFLTROOT)) 1489 if (!vfs_mountroot_try(ROOTDEVNAME)) 1490 return; 1491 #endif 1492 1493 /* 1494 * Everything so far has failed, prompt on the console if we haven't 1495 * already tried that. 1496 */ 1497 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 1498 return; 1499 panic("Root mount failed, startup aborted."); 1500 } 1501 1502 /* 1503 * Mount (mountfrom) as the root filesystem. 1504 */ 1505 static int 1506 vfs_mountroot_try(char *mountfrom) 1507 { 1508 struct mount *mp; 1509 char *vfsname, *path; 1510 const char *devname; 1511 int error; 1512 char patt[32]; 1513 int s; 1514 1515 vfsname = NULL; 1516 path = NULL; 1517 mp = NULL; 1518 error = EINVAL; 1519 1520 if (mountfrom == NULL) 1521 return(error); /* don't complain */ 1522 1523 s = splcam(); /* Overkill, but annoying without it */ 1524 printf("Mounting root from %s\n", mountfrom); 1525 splx(s); 1526 1527 /* parse vfs name and path */ 1528 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1529 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1530 vfsname[0] = path[0] = 0; 1531 sprintf(patt, "%%%d[a-z0-9]:%%%zds", MFSNAMELEN, MNAMELEN); 1532 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1533 goto done; 1534 1535 /* allocate a root mount */ 1536 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 1537 &mp); 1538 if (error != 0) { 1539 printf("Can't allocate root mount for filesystem '%s': %d\n", 1540 vfsname, error); 1541 goto done; 1542 } 1543 mp->mnt_flag |= MNT_ROOTFS; 1544 1545 /* do our best to set rootdev */ 1546 if ((path[0] != 0) && setrootbyname(path)) 1547 printf("setrootbyname failed\n"); 1548 1549 /* If the root device is a type "memory disk", mount RW */ 1550 if (rootdev != NODEV && devsw(rootdev) != NULL) { 1551 devname = devtoname(rootdev); 1552 if (devname[0] == 'm' && devname[1] == 'd') 1553 mp->mnt_flag &= ~MNT_RDONLY; 1554 } 1555 1556 /* 1557 * Set the mount path to be something useful, because the 1558 * filesystem code isn't responsible now for initialising 1559 * f_mntonname unless they want to override the default 1560 * (which is `path'.) 1561 */ 1562 strlcpy(mp->mnt_stat.f_mntonname, "/", MNAMELEN); 1563 1564 error = VFS_MOUNT(mp, NULL, NULL, NULL, curthread); 1565 1566 done: 1567 if (vfsname != NULL) 1568 free(vfsname, M_MOUNT); 1569 if (path != NULL) 1570 free(path, M_MOUNT); 1571 if (error != 0) { 1572 if (mp != NULL) { 1573 vfs_unbusy(mp, curthread); 1574 #ifdef MAC 1575 mac_destroy_mount(mp); 1576 #endif 1577 crfree(mp->mnt_cred); 1578 free(mp, M_MOUNT); 1579 } 1580 printf("Root mount failed: %d\n", error); 1581 } else { 1582 1583 /* register with list of mounted filesystems */ 1584 mtx_lock(&mountlist_mtx); 1585 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1586 mtx_unlock(&mountlist_mtx); 1587 1588 /* sanity check system clock against root fs timestamp */ 1589 inittodr(mp->mnt_time); 1590 vfs_unbusy(mp, curthread); 1591 error = VFS_START(mp, 0, curthread); 1592 } 1593 return(error); 1594 } 1595 1596 /* 1597 * Spin prompting on the console for a suitable root filesystem 1598 */ 1599 static int 1600 vfs_mountroot_ask(void) 1601 { 1602 char name[128]; 1603 int i; 1604 dev_t dev; 1605 1606 for(;;) { 1607 printf("\nManual root filesystem specification:\n"); 1608 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1609 #if defined(__i386__) || defined(__ia64__) 1610 printf(" eg. ufs:da0s1a\n"); 1611 #else 1612 printf(" eg. ufs:/dev/da0a\n"); 1613 #endif 1614 printf(" ? List valid disk boot devices\n"); 1615 printf(" <empty line> Abort manual input\n"); 1616 printf("\nmountroot> "); 1617 gets(name); 1618 if (name[0] == 0) 1619 return(1); 1620 if (name[0] == '?') { 1621 if (!g_dev_print()) { 1622 printf("Possibly valid devices for 'ufs' root:\n"); 1623 for (i = 0; i < NUMCDEVSW; i++) { 1624 dev = makedev(i, 0); 1625 if (devsw(dev) != NULL) 1626 printf(" \"%s\"", devsw(dev)->d_name); 1627 } 1628 } 1629 printf("\n"); 1630 continue; 1631 } 1632 if (!vfs_mountroot_try(name)) 1633 return(0); 1634 } 1635 } 1636 1637 /* 1638 * Local helper function for vfs_mountroot_ask. 1639 */ 1640 static void 1641 gets(char *cp) 1642 { 1643 char *lp; 1644 int c; 1645 1646 lp = cp; 1647 for (;;) { 1648 printf("%c", c = cngetc() & 0177); 1649 switch (c) { 1650 case -1: 1651 case '\n': 1652 case '\r': 1653 *lp++ = '\0'; 1654 return; 1655 case '\b': 1656 case '\177': 1657 if (lp > cp) { 1658 printf(" \b"); 1659 lp--; 1660 } 1661 continue; 1662 case '#': 1663 lp--; 1664 if (lp < cp) 1665 lp = cp; 1666 continue; 1667 case '@': 1668 case 'u' & 037: 1669 lp = cp; 1670 printf("%c", '\n'); 1671 continue; 1672 default: 1673 *lp++ = c; 1674 } 1675 } 1676 } 1677 1678 /* 1679 * Convert a given name to the dev_t of the disk-like device 1680 * it refers to. 1681 */ 1682 dev_t 1683 getdiskbyname(char *name) { 1684 char *cp; 1685 dev_t dev; 1686 1687 cp = name; 1688 if (!bcmp(cp, "/dev/", 5)) 1689 cp += 5; 1690 1691 dev = NODEV; 1692 EVENTHANDLER_INVOKE(dev_clone, cp, strlen(cp), &dev); 1693 return (dev); 1694 } 1695 1696 /* 1697 * Set rootdev to match (name), given that we expect it to 1698 * refer to a disk-like device. 1699 */ 1700 static int 1701 setrootbyname(char *name) 1702 { 1703 dev_t diskdev; 1704 1705 diskdev = getdiskbyname(name); 1706 if (diskdev != NODEV) { 1707 rootdev = diskdev; 1708 return (0); 1709 } 1710 1711 return (1); 1712 } 1713 1714 /* Show the dev_t for a disk specified by name */ 1715 #ifdef DDB 1716 DB_SHOW_COMMAND(disk, db_getdiskbyname) 1717 { 1718 dev_t dev; 1719 1720 if (modif[0] == '\0') { 1721 db_error("usage: show disk/devicename"); 1722 return; 1723 } 1724 dev = getdiskbyname(modif); 1725 if (dev != NODEV) 1726 db_printf("dev_t = %p\n", dev); 1727 else 1728 db_printf("No disk device matched.\n"); 1729 } 1730 #endif 1731 1732 /* 1733 * Get a mount option by its name. 1734 * 1735 * Return 0 if the option was found, ENOENT otherwise. 1736 * If len is non-NULL it will be filled with the length 1737 * of the option. If buf is non-NULL, it will be filled 1738 * with the address of the option. 1739 */ 1740 int 1741 vfs_getopt(opts, name, buf, len) 1742 struct vfsoptlist *opts; 1743 const char *name; 1744 void **buf; 1745 int *len; 1746 { 1747 struct vfsopt *opt; 1748 1749 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1750 1751 TAILQ_FOREACH(opt, opts, link) { 1752 if (strcmp(name, opt->name) == 0) { 1753 if (len != NULL) 1754 *len = opt->len; 1755 if (buf != NULL) 1756 *buf = opt->value; 1757 return (0); 1758 } 1759 } 1760 return (ENOENT); 1761 } 1762 1763 /* 1764 * Find and copy a mount option. 1765 * 1766 * The size of the buffer has to be specified 1767 * in len, if it is not the same length as the 1768 * mount option, EINVAL is returned. 1769 * Returns ENOENT if the option is not found. 1770 */ 1771 int 1772 vfs_copyopt(opts, name, dest, len) 1773 struct vfsoptlist *opts; 1774 const char *name; 1775 void *dest; 1776 int len; 1777 { 1778 struct vfsopt *opt; 1779 1780 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1781 1782 TAILQ_FOREACH(opt, opts, link) { 1783 if (strcmp(name, opt->name) == 0) { 1784 if (len != opt->len) 1785 return (EINVAL); 1786 bcopy(opt->value, dest, opt->len); 1787 return (0); 1788 } 1789 } 1790 return (ENOENT); 1791 }
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