vfs_mount.c revision 132710
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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * Copyright (c) 1999 Michael Smith 35 * All rights reserved. 36 * Copyright (c) 1999 Poul-Henning Kamp 37 * All rights reserved. 38 * 39 * Redistribution and use in source and binary forms, with or without 40 * modification, are permitted provided that the following conditions 41 * are met: 42 * 1. Redistributions of source code must retain the above copyright 43 * notice, this list of conditions and the following disclaimer. 44 * 2. Redistributions in binary form must reproduce the above copyright 45 * notice, this list of conditions and the following disclaimer in the 46 * documentation and/or other materials provided with the distribution. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 */ 60 61#include <sys/cdefs.h> 62__FBSDID("$FreeBSD: head/sys/kern/vfs_mount.c 132710 2004-07-27 22:32:01Z phk $"); 63 64#include <sys/param.h> 65#include <sys/conf.h> 66#include <sys/cons.h> 67#include <sys/jail.h> 68#include <sys/kernel.h> 69#include <sys/linker.h> 70#include <sys/mac.h> 71#include <sys/malloc.h> 72#include <sys/mount.h> 73#include <sys/mutex.h> 74#include <sys/namei.h> 75#include <sys/proc.h> 76#include <sys/filedesc.h> 77#include <sys/reboot.h> 78#include <sys/sysproto.h> 79#include <sys/sx.h> 80#include <sys/sysctl.h> 81#include <sys/sysent.h> 82#include <sys/systm.h> 83#include <sys/vnode.h> 84 85#include <geom/geom.h> 86 87#include <machine/stdarg.h> 88 89#include "opt_rootdevname.h" 90#include "opt_ddb.h" 91#include "opt_mac.h" 92 93#ifdef DDB 94#include <ddb/ddb.h> 95#endif 96 97#define ROOTNAME "root_device" 98#define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 99 100static void checkdirs(struct vnode *olddp, struct vnode *newdp); 101static void gets(char *cp); 102static int vfs_domount(struct thread *td, const char *fstype, 103 char *fspath, int fsflags, void *fsdata, int compat); 104static int vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp, 105 const char *fspath, struct thread *td, struct mount **mpp); 106static int vfs_mountroot_ask(void); 107static int vfs_mountroot_try(char *mountfrom); 108static int vfs_donmount(struct thread *td, int fsflags, 109 struct uio *fsoptions); 110 111static int usermount = 0; 112SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 113 "Unprivileged users may mount and unmount file systems"); 114 115MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 116 117/* List of mounted filesystems. */ 118struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 119 120/* For any iteration/modification of mountlist */ 121struct mtx mountlist_mtx; 122 123/* 124 * The vnode of the system's root (/ in the filesystem, without chroot 125 * active.) 126 */ 127struct vnode *rootvnode; 128 129/* 130 * The root filesystem is detailed in the kernel environment variable 131 * vfs.root.mountfrom, which is expected to be in the general format 132 * 133 * <vfsname>:[<path>] 134 * vfsname := the name of a VFS known to the kernel and capable 135 * of being mounted as root 136 * path := disk device name or other data used by the filesystem 137 * to locate its physical store 138 */ 139 140/* 141 * The root specifiers we will try if RB_CDROM is specified. 142 */ 143static char *cdrom_rootdevnames[] = { 144 "cd9660:cd0", 145 "cd9660:acd0", 146 NULL 147}; 148 149/* legacy find-root code */ 150char *rootdevnames[2] = {NULL, NULL}; 151static int setrootbyname(char *name); 152struct cdev *rootdev = NULL; 153 154/* 155 * Has to be dynamic as the value of rootdev can change; however, it can't 156 * change after the root is mounted, so a user process can't access this 157 * sysctl until after the value is unchangeable. 158 */ 159static int 160sysctl_rootdev(SYSCTL_HANDLER_ARGS) 161{ 162 int error; 163 164 /* _RD prevents this from happening. */ 165 KASSERT(req->newptr == NULL, ("Attempt to change root device name")); 166 167 if (rootdev != NULL) 168 error = sysctl_handle_string(oidp, rootdev->si_name, 0, req); 169 else 170 error = sysctl_handle_string(oidp, "", 0, req); 171 172 return (error); 173} 174 175SYSCTL_PROC(_kern, OID_AUTO, rootdev, CTLTYPE_STRING | CTLFLAG_RD, 176 0, 0, sysctl_rootdev, "A", "Root file system device"); 177 178/* Remove one mount option. */ 179static void 180vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 181{ 182 183 TAILQ_REMOVE(opts, opt, link); 184 free(opt->name, M_MOUNT); 185 if (opt->value != NULL) 186 free(opt->value, M_MOUNT); 187#ifdef INVARIANTS 188 else if (opt->len != 0) 189 panic("%s: mount option with NULL value but length != 0", 190 __func__); 191#endif 192 free(opt, M_MOUNT); 193} 194 195/* Release all resources related to the mount options. */ 196static void 197vfs_freeopts(struct vfsoptlist *opts) 198{ 199 struct vfsopt *opt; 200 201 while (!TAILQ_EMPTY(opts)) { 202 opt = TAILQ_FIRST(opts); 203 vfs_freeopt(opts, opt); 204 } 205 free(opts, M_MOUNT); 206} 207 208/* 209 * Check if options are equal (with or without the "no" prefix). 210 */ 211static int 212vfs_equalopts(const char *opt1, const char *opt2) 213{ 214 215 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 216 if (strcmp(opt1, opt2) == 0) 217 return (1); 218 /* "noopt" vs. "opt" */ 219 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 220 return (1); 221 /* "opt" vs. "noopt" */ 222 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 223 return (1); 224 return (0); 225} 226 227/* 228 * If a mount option is specified several times, 229 * (with or without the "no" prefix) only keep 230 * the last occurence of it. 231 */ 232static void 233vfs_sanitizeopts(struct vfsoptlist *opts) 234{ 235 struct vfsopt *opt, *opt2, *tmp; 236 237 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 238 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 239 while (opt2 != NULL) { 240 if (vfs_equalopts(opt->name, opt2->name)) { 241 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 242 vfs_freeopt(opts, opt2); 243 opt2 = tmp; 244 } else { 245 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 246 } 247 } 248 } 249} 250 251/* 252 * Build a linked list of mount options from a struct uio. 253 */ 254static int 255vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 256{ 257 struct vfsoptlist *opts; 258 struct vfsopt *opt; 259 size_t memused; 260 unsigned int i, iovcnt; 261 int error, namelen, optlen; 262 263 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 264 TAILQ_INIT(opts); 265 memused = 0; 266 iovcnt = auio->uio_iovcnt; 267 for (i = 0; i < iovcnt; i += 2) { 268 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 269 namelen = auio->uio_iov[i].iov_len; 270 optlen = auio->uio_iov[i + 1].iov_len; 271 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 272 opt->value = NULL; 273 opt->len = optlen; 274 275 /* 276 * Do this early, so jumps to "bad" will free the current 277 * option. 278 */ 279 TAILQ_INSERT_TAIL(opts, opt, link); 280 memused += sizeof(struct vfsopt) + optlen + namelen; 281 282 /* 283 * Avoid consuming too much memory, and attempts to overflow 284 * memused. 285 */ 286 if (memused > VFS_MOUNTARG_SIZE_MAX || 287 optlen > VFS_MOUNTARG_SIZE_MAX || 288 namelen > VFS_MOUNTARG_SIZE_MAX) { 289 error = EINVAL; 290 goto bad; 291 } 292 293 if (auio->uio_segflg == UIO_SYSSPACE) { 294 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 295 } else { 296 error = copyin(auio->uio_iov[i].iov_base, opt->name, 297 namelen); 298 if (error) 299 goto bad; 300 } 301 /* Ensure names are null-terminated strings. */ 302 if (opt->name[namelen - 1] != '\0') { 303 error = EINVAL; 304 goto bad; 305 } 306 if (optlen != 0) { 307 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 308 if (auio->uio_segflg == UIO_SYSSPACE) { 309 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 310 optlen); 311 } else { 312 error = copyin(auio->uio_iov[i + 1].iov_base, 313 opt->value, optlen); 314 if (error) 315 goto bad; 316 } 317 } 318 } 319 vfs_sanitizeopts(opts); 320 *options = opts; 321 return (0); 322bad: 323 vfs_freeopts(opts); 324 return (error); 325} 326 327/* 328 * Merge the old mount options with the new ones passed 329 * in the MNT_UPDATE case. 330 */ 331static void 332vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 333{ 334 struct vfsopt *opt, *opt2, *new; 335 336 TAILQ_FOREACH(opt, opts, link) { 337 /* 338 * Check that this option hasn't been redefined 339 * nor cancelled with a "no" mount option. 340 */ 341 opt2 = TAILQ_FIRST(toopts); 342 while (opt2 != NULL) { 343 if (strcmp(opt2->name, opt->name) == 0) 344 goto next; 345 if (strncmp(opt2->name, "no", 2) == 0 && 346 strcmp(opt2->name + 2, opt->name) == 0) { 347 vfs_freeopt(toopts, opt2); 348 goto next; 349 } 350 opt2 = TAILQ_NEXT(opt2, link); 351 } 352 /* We want this option, duplicate it. */ 353 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 354 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 355 strcpy(new->name, opt->name); 356 if (opt->len != 0) { 357 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 358 bcopy(opt->value, new->value, opt->len); 359 } else { 360 new->value = NULL; 361 } 362 new->len = opt->len; 363 TAILQ_INSERT_TAIL(toopts, new, link); 364next: 365 continue; 366 } 367} 368 369/* 370 * New mount API. 371 */ 372int 373nmount(td, uap) 374 struct thread *td; 375 struct nmount_args /* { 376 struct iovec *iovp; 377 unsigned int iovcnt; 378 int flags; 379 } */ *uap; 380{ 381 struct uio *auio; 382 struct iovec *iov; 383 unsigned int i; 384 int error; 385 u_int iovcnt; 386 387 iovcnt = uap->iovcnt; 388 /* 389 * Check that we have an even number of iovec's 390 * and that we have at least two options. 391 */ 392 if ((iovcnt & 1) || (iovcnt < 4)) 393 return (EINVAL); 394 error = copyinuio(uap->iovp, iovcnt, &auio); 395 if (error) 396 return (error); 397 iov = auio->uio_iov; 398 for (i = 0; i < iovcnt; i++) { 399 if (iov->iov_len > MMAXOPTIONLEN) { 400 free(auio, M_IOV); 401 return (EINVAL); 402 } 403 iov++; 404 } 405 error = vfs_donmount(td, uap->flags, auio); 406 free(auio, M_IOV); 407 return (error); 408} 409 410int 411kernel_mount(struct iovec *iovp, u_int iovcnt, int flags) 412{ 413 struct uio auio; 414 int error; 415 416 /* 417 * Check that we have an even number of iovec's 418 * and that we have at least two options. 419 */ 420 if ((iovcnt & 1) || (iovcnt < 4)) 421 return (EINVAL); 422 423 auio.uio_iov = iovp; 424 auio.uio_iovcnt = iovcnt; 425 auio.uio_segflg = UIO_SYSSPACE; 426 427 error = vfs_donmount(curthread, flags, &auio); 428 return (error); 429} 430 431int 432kernel_vmount(int flags, ...) 433{ 434 struct iovec *iovp; 435 struct uio auio; 436 va_list ap; 437 u_int iovcnt, iovlen, len; 438 const char *cp; 439 char *buf, *pos; 440 size_t n; 441 int error, i; 442 443 len = 0; 444 va_start(ap, flags); 445 for (iovcnt = 0; (cp = va_arg(ap, const char *)) != NULL; iovcnt++) 446 len += strlen(cp) + 1; 447 va_end(ap); 448 449 if (iovcnt < 4 || iovcnt & 1) 450 return (EINVAL); 451 452 iovlen = iovcnt * sizeof (struct iovec); 453 MALLOC(iovp, struct iovec *, iovlen, M_MOUNT, M_WAITOK); 454 MALLOC(buf, char *, len, M_MOUNT, M_WAITOK); 455 pos = buf; 456 va_start(ap, flags); 457 for (i = 0; i < iovcnt; i++) { 458 cp = va_arg(ap, const char *); 459 copystr(cp, pos, len - (pos - buf), &n); 460 iovp[i].iov_base = pos; 461 iovp[i].iov_len = n; 462 pos += n; 463 } 464 va_end(ap); 465 466 auio.uio_iov = iovp; 467 auio.uio_iovcnt = iovcnt; 468 auio.uio_segflg = UIO_SYSSPACE; 469 470 error = vfs_donmount(curthread, flags, &auio); 471 FREE(iovp, M_MOUNT); 472 FREE(buf, M_MOUNT); 473 return (error); 474} 475 476/* 477 * Allocate and initialize the mount point struct. 478 */ 479static int 480vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 481 const char *fspath, struct thread *td, struct mount **mpp) 482{ 483 struct mount *mp; 484 485 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 486 TAILQ_INIT(&mp->mnt_nvnodelist); 487 mp->mnt_nvnodelistsize = 0; 488 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 489 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 490 vfs_busy(mp, LK_NOWAIT, 0, td); 491 mp->mnt_op = vfsp->vfc_vfsops; 492 mp->mnt_vfc = vfsp; 493 vfsp->vfc_refcount++; 494 mp->mnt_stat.f_type = vfsp->vfc_typenum; 495 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 496 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 497 mp->mnt_vnodecovered = vp; 498 mp->mnt_cred = crdup(td->td_ucred); 499 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 500 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 501 mp->mnt_iosize_max = DFLTPHYS; 502#ifdef MAC 503 mac_init_mount(mp); 504 mac_create_mount(td->td_ucred, mp); 505#endif 506 *mpp = mp; 507 return (0); 508} 509 510/* 511 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 512 */ 513void 514vfs_mount_destroy(struct mount *mp, struct thread *td) 515{ 516 517 mp->mnt_vfc->vfc_refcount--; 518 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 519 panic("unmount: dangling vnode"); 520 vfs_unbusy(mp,td); 521 lockdestroy(&mp->mnt_lock); 522 mtx_destroy(&mp->mnt_mtx); 523 if (mp->mnt_kern_flag & MNTK_MWAIT) 524 wakeup(mp); 525#ifdef MAC 526 mac_destroy_mount(mp); 527#endif 528 if (mp->mnt_opt != NULL) 529 vfs_freeopts(mp->mnt_opt); 530 crfree(mp->mnt_cred); 531 free(mp, M_MOUNT); 532} 533 534static int 535vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 536{ 537 struct vfsoptlist *optlist; 538 char *fstype, *fspath; 539 int error, fstypelen, fspathlen; 540 541 error = vfs_buildopts(fsoptions, &optlist); 542 if (error) 543 return (error); 544 545 /* 546 * We need these two options before the others, 547 * and they are mandatory for any filesystem. 548 * Ensure they are NUL terminated as well. 549 */ 550 fstypelen = 0; 551 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 552 if (error || fstype[fstypelen - 1] != '\0') { 553 error = EINVAL; 554 goto bail; 555 } 556 fspathlen = 0; 557 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 558 if (error || fspath[fspathlen - 1] != '\0') { 559 error = EINVAL; 560 goto bail; 561 } 562 563 /* 564 * Be ultra-paranoid about making sure the type and fspath 565 * variables will fit in our mp buffers, including the 566 * terminating NUL. 567 */ 568 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 569 error = ENAMETOOLONG; 570 goto bail; 571 } 572 573 error = vfs_domount(td, fstype, fspath, fsflags, optlist, 0); 574bail: 575 if (error) 576 vfs_freeopts(optlist); 577 return (error); 578} 579 580/* 581 * Old mount API. 582 */ 583#ifndef _SYS_SYSPROTO_H_ 584struct mount_args { 585 char *type; 586 char *path; 587 int flags; 588 caddr_t data; 589}; 590#endif 591/* ARGSUSED */ 592int 593mount(td, uap) 594 struct thread *td; 595 struct mount_args /* { 596 char *type; 597 char *path; 598 int flags; 599 caddr_t data; 600 } */ *uap; 601{ 602 char *fstype; 603 char *fspath; 604 int error; 605 606 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 607 fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK); 608 609 /* 610 * vfs_mount() actually takes a kernel string for `type' and 611 * `path' now, so extract them. 612 */ 613 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 614 if (error == 0) 615 error = copyinstr(uap->path, fspath, MNAMELEN, NULL); 616 if (error == 0) 617 error = vfs_domount(td, fstype, fspath, uap->flags, 618 uap->data, 1); 619 free(fstype, M_TEMP); 620 free(fspath, M_TEMP); 621 return (error); 622} 623 624/* 625 * vfs_mount(): actually attempt a filesystem mount. 626 * 627 * This routine is designed to be a "generic" entry point for routines 628 * that wish to mount a filesystem. All parameters except `fsdata' are 629 * pointers into kernel space. `fsdata' is currently still a pointer 630 * into userspace. 631 */ 632int 633vfs_mount(td, fstype, fspath, fsflags, fsdata) 634 struct thread *td; 635 const char *fstype; 636 char *fspath; 637 int fsflags; 638 void *fsdata; 639{ 640 641 return (vfs_domount(td, fstype, fspath, fsflags, fsdata, 1)); 642} 643 644/* 645 * vfs_domount(): actually attempt a filesystem mount. 646 */ 647static int 648vfs_domount( 649 struct thread *td, /* Flags common to all filesystems. */ 650 const char *fstype, /* Filesystem type. */ 651 char *fspath, /* Mount path. */ 652 int fsflags, /* Flags common to all filesystems. */ 653 void *fsdata, /* Options local to the filesystem. */ 654 int compat /* Invocation from compat syscall. */ 655 ) 656{ 657 linker_file_t lf; 658 struct vnode *vp; 659 struct mount *mp; 660 struct vfsconf *vfsp; 661 int error, flag = 0, kern_flag = 0; 662 struct vattr va; 663 struct nameidata nd; 664 665 /* 666 * Be ultra-paranoid about making sure the type and fspath 667 * variables will fit in our mp buffers, including the 668 * terminating NUL. 669 */ 670 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 671 return (ENAMETOOLONG); 672 673 if (jailed(td->td_ucred)) 674 return (EPERM); 675 if (usermount == 0) { 676 if ((error = suser(td)) != 0) 677 return (error); 678 } 679 680 /* 681 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 682 */ 683 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 684 if ((error = suser(td)) != 0) 685 return (error); 686 } 687 /* 688 * Silently enforce MNT_NODEV, MNT_NOSUID and MNT_USER for 689 * unprivileged users. 690 */ 691 if (suser(td) != 0) 692 fsflags |= MNT_NODEV | MNT_NOSUID | MNT_USER; 693 /* 694 * Get vnode to be covered 695 */ 696 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 697 if ((error = namei(&nd)) != 0) 698 return (error); 699 NDFREE(&nd, NDF_ONLY_PNBUF); 700 vp = nd.ni_vp; 701 if (fsflags & MNT_UPDATE) { 702 if ((vp->v_vflag & VV_ROOT) == 0) { 703 vput(vp); 704 return (EINVAL); 705 } 706 mp = vp->v_mount; 707 flag = mp->mnt_flag; 708 kern_flag = mp->mnt_kern_flag; 709 /* 710 * We only allow the filesystem to be reloaded if it 711 * is currently mounted read-only. 712 */ 713 if ((fsflags & MNT_RELOAD) && 714 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 715 vput(vp); 716 return (EOPNOTSUPP); /* Needs translation */ 717 } 718 /* 719 * Only privileged root, or (if MNT_USER is set) the user that 720 * did the original mount is permitted to update it. 721 */ 722 error = vfs_suser(mp, td); 723 if (error) { 724 vput(vp); 725 return (error); 726 } 727 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 728 vput(vp); 729 return (EBUSY); 730 } 731 VI_LOCK(vp); 732 if ((vp->v_iflag & VI_MOUNT) != 0 || 733 vp->v_mountedhere != NULL) { 734 VI_UNLOCK(vp); 735 vfs_unbusy(mp, td); 736 vput(vp); 737 return (EBUSY); 738 } 739 vp->v_iflag |= VI_MOUNT; 740 VI_UNLOCK(vp); 741 mp->mnt_flag |= fsflags & 742 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT); 743 VOP_UNLOCK(vp, 0, td); 744 if (compat == 0) { 745 mp->mnt_optnew = fsdata; 746 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 747 } 748 } else { 749 /* 750 * If the user is not root, ensure that they own the directory 751 * onto which we are attempting to mount. 752 */ 753 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 754 if (error) { 755 vput(vp); 756 return (error); 757 } 758 if (va.va_uid != td->td_ucred->cr_uid) { 759 if ((error = suser(td)) != 0) { 760 vput(vp); 761 return (error); 762 } 763 } 764 if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) { 765 vput(vp); 766 return (error); 767 } 768 if (vp->v_type != VDIR) { 769 vput(vp); 770 return (ENOTDIR); 771 } 772 vfsp = vfs_byname(fstype); 773 if (vfsp == NULL) { 774 /* Only load modules for root (very important!). */ 775 if ((error = suser(td)) != 0) { 776 vput(vp); 777 return (error); 778 } 779 error = securelevel_gt(td->td_ucred, 0); 780 if (error) { 781 vput(vp); 782 return (error); 783 } 784 error = linker_load_module(NULL, fstype, NULL, NULL, &lf); 785 if (error || lf == NULL) { 786 vput(vp); 787 if (lf == NULL) 788 error = ENODEV; 789 return (error); 790 } 791 lf->userrefs++; 792 /* Look up again to see if the VFS was loaded. */ 793 vfsp = vfs_byname(fstype); 794 if (vfsp == NULL) { 795 lf->userrefs--; 796 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 797 vput(vp); 798 return (ENODEV); 799 } 800 } 801 VI_LOCK(vp); 802 if ((vp->v_iflag & VI_MOUNT) != 0 || 803 vp->v_mountedhere != NULL) { 804 VI_UNLOCK(vp); 805 vput(vp); 806 return (EBUSY); 807 } 808 vp->v_iflag |= VI_MOUNT; 809 VI_UNLOCK(vp); 810 811 /* 812 * Allocate and initialize the filesystem. 813 */ 814 error = vfs_mount_alloc(vp, vfsp, fspath, td, &mp); 815 if (error) { 816 vput(vp); 817 return (error); 818 } 819 VOP_UNLOCK(vp, 0, td); 820 821 /* XXXMAC: pass to vfs_mount_alloc? */ 822 if (compat == 0) 823 mp->mnt_optnew = fsdata; 824 } 825 /* 826 * Check if the fs implements the type VFS_[N]MOUNT() 827 * function we are looking for. 828 */ 829 if ((compat == 0) == (mp->mnt_op->vfs_mount != NULL)) { 830 printf("%s doesn't support the %s mount syscall\n", 831 mp->mnt_vfc->vfc_name, compat ? "old" : "new"); 832 VI_LOCK(vp); 833 vp->v_iflag &= ~VI_MOUNT; 834 VI_UNLOCK(vp); 835 if (mp->mnt_flag & MNT_UPDATE) 836 vfs_unbusy(mp, td); 837 else 838 vfs_mount_destroy(mp, td); 839 vrele(vp); 840 return (EOPNOTSUPP); 841 } 842 843 /* 844 * Set the mount level flags. 845 */ 846 if (fsflags & MNT_RDONLY) 847 mp->mnt_flag |= MNT_RDONLY; 848 else if (mp->mnt_flag & MNT_RDONLY) 849 mp->mnt_kern_flag |= MNTK_WANTRDWR; 850 mp->mnt_flag &=~ MNT_UPDATEMASK; 851 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE); 852 /* 853 * Mount the filesystem. 854 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 855 * get. No freeing of cn_pnbuf. 856 */ 857 error = compat ? VFS_MOUNT(mp, fspath, fsdata, &nd, td) : 858 VFS_NMOUNT(mp, &nd, td); 859 if (!error) { 860 if (mp->mnt_opt != NULL) 861 vfs_freeopts(mp->mnt_opt); 862 mp->mnt_opt = mp->mnt_optnew; 863 } 864 /* 865 * Prevent external consumers of mount options from reading 866 * mnt_optnew. 867 */ 868 mp->mnt_optnew = NULL; 869 if (mp->mnt_flag & MNT_UPDATE) { 870 if (mp->mnt_kern_flag & MNTK_WANTRDWR) 871 mp->mnt_flag &= ~MNT_RDONLY; 872 mp->mnt_flag &= 873 ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 874 mp->mnt_kern_flag &= ~MNTK_WANTRDWR; 875 if (error) { 876 mp->mnt_flag = flag; 877 mp->mnt_kern_flag = kern_flag; 878 } 879 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 880 if (mp->mnt_syncer == NULL) 881 error = vfs_allocate_syncvnode(mp); 882 } else { 883 if (mp->mnt_syncer != NULL) 884 vrele(mp->mnt_syncer); 885 mp->mnt_syncer = NULL; 886 } 887 vfs_unbusy(mp, td); 888 VI_LOCK(vp); 889 vp->v_iflag &= ~VI_MOUNT; 890 VI_UNLOCK(vp); 891 vrele(vp); 892 return (error); 893 } 894 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 895 /* 896 * Put the new filesystem on the mount list after root. 897 */ 898 cache_purge(vp); 899 if (!error) { 900 struct vnode *newdp; 901 902 VI_LOCK(vp); 903 vp->v_iflag &= ~VI_MOUNT; 904 VI_UNLOCK(vp); 905 vp->v_mountedhere = mp; 906 mtx_lock(&mountlist_mtx); 907 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 908 mtx_unlock(&mountlist_mtx); 909 vfs_event_signal(NULL, VQ_MOUNT, 0); 910 if (VFS_ROOT(mp, &newdp, td)) 911 panic("mount: lost mount"); 912 checkdirs(vp, newdp); 913 vput(newdp); 914 VOP_UNLOCK(vp, 0, td); 915 if ((mp->mnt_flag & MNT_RDONLY) == 0) 916 error = vfs_allocate_syncvnode(mp); 917 vfs_unbusy(mp, td); 918 if (error || (error = VFS_START(mp, 0, td)) != 0) 919 vrele(vp); 920 } else { 921 VI_LOCK(vp); 922 vp->v_iflag &= ~VI_MOUNT; 923 VI_UNLOCK(vp); 924 vfs_mount_destroy(mp, td); 925 vput(vp); 926 } 927 return (error); 928} 929 930/* 931 * Scan all active processes to see if any of them have a current 932 * or root directory of `olddp'. If so, replace them with the new 933 * mount point. 934 */ 935static void 936checkdirs(olddp, newdp) 937 struct vnode *olddp, *newdp; 938{ 939 struct filedesc *fdp; 940 struct proc *p; 941 int nrele; 942 943 if (vrefcnt(olddp) == 1) 944 return; 945 sx_slock(&allproc_lock); 946 LIST_FOREACH(p, &allproc, p_list) { 947 mtx_lock(&fdesc_mtx); 948 fdp = p->p_fd; 949 if (fdp == NULL) { 950 mtx_unlock(&fdesc_mtx); 951 continue; 952 } 953 nrele = 0; 954 FILEDESC_LOCK(fdp); 955 if (fdp->fd_cdir == olddp) { 956 VREF(newdp); 957 fdp->fd_cdir = newdp; 958 nrele++; 959 } 960 if (fdp->fd_rdir == olddp) { 961 VREF(newdp); 962 fdp->fd_rdir = newdp; 963 nrele++; 964 } 965 FILEDESC_UNLOCK(fdp); 966 mtx_unlock(&fdesc_mtx); 967 while (nrele--) 968 vrele(olddp); 969 } 970 sx_sunlock(&allproc_lock); 971 if (rootvnode == olddp) { 972 vrele(rootvnode); 973 VREF(newdp); 974 rootvnode = newdp; 975 } 976} 977 978/* 979 * Unmount a filesystem. 980 * 981 * Note: unmount takes a path to the vnode mounted on as argument, 982 * not special file (as before). 983 */ 984#ifndef _SYS_SYSPROTO_H_ 985struct unmount_args { 986 char *path; 987 int flags; 988}; 989#endif 990/* ARGSUSED */ 991int 992unmount(td, uap) 993 struct thread *td; 994 register struct unmount_args /* { 995 char *path; 996 int flags; 997 } */ *uap; 998{ 999 struct mount *mp; 1000 char *pathbuf; 1001 int error, id0, id1; 1002 1003 if (jailed(td->td_ucred)) 1004 return (EPERM); 1005 if (usermount == 0) { 1006 if ((error = suser(td)) != 0) 1007 return (error); 1008 } 1009 1010 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1011 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1012 if (error) { 1013 free(pathbuf, M_TEMP); 1014 return (error); 1015 } 1016 if (uap->flags & MNT_BYFSID) { 1017 /* Decode the filesystem ID. */ 1018 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1019 free(pathbuf, M_TEMP); 1020 return (EINVAL); 1021 } 1022 1023 mtx_lock(&mountlist_mtx); 1024 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1025 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1026 mp->mnt_stat.f_fsid.val[1] == id1) 1027 break; 1028 } 1029 mtx_unlock(&mountlist_mtx); 1030 } else { 1031 mtx_lock(&mountlist_mtx); 1032 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1033 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1034 break; 1035 } 1036 mtx_unlock(&mountlist_mtx); 1037 } 1038 free(pathbuf, M_TEMP); 1039 if (mp == NULL) { 1040 /* 1041 * Previously we returned ENOENT for a nonexistent path and 1042 * EINVAL for a non-mountpoint. We cannot tell these apart 1043 * now, so in the !MNT_BYFSID case return the more likely 1044 * EINVAL for compatibility. 1045 */ 1046 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1047 } 1048 1049 /* 1050 * Only privileged root, or (if MNT_USER is set) the user that did the 1051 * original mount is permitted to unmount this filesystem. 1052 */ 1053 error = vfs_suser(mp, td); 1054 if (error) 1055 return (error); 1056 1057 /* 1058 * Don't allow unmounting the root filesystem. 1059 */ 1060 if (mp->mnt_flag & MNT_ROOTFS) 1061 return (EINVAL); 1062 return (dounmount(mp, uap->flags, td)); 1063} 1064 1065/* 1066 * Do the actual filesystem unmount. 1067 */ 1068int 1069dounmount(mp, flags, td) 1070 struct mount *mp; 1071 int flags; 1072 struct thread *td; 1073{ 1074 struct vnode *coveredvp, *fsrootvp; 1075 int error; 1076 int async_flag; 1077 1078 mtx_lock(&mountlist_mtx); 1079 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1080 mtx_unlock(&mountlist_mtx); 1081 return (EBUSY); 1082 } 1083 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1084 /* Allow filesystems to detect that a forced unmount is in progress. */ 1085 if (flags & MNT_FORCE) 1086 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1087 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1088 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); 1089 if (error) { 1090 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1091 if (mp->mnt_kern_flag & MNTK_MWAIT) 1092 wakeup(mp); 1093 return (error); 1094 } 1095 vn_start_write(NULL, &mp, V_WAIT); 1096 1097 if (mp->mnt_flag & MNT_EXPUBLIC) 1098 vfs_setpublicfs(NULL, NULL, NULL); 1099 1100 vfs_msync(mp, MNT_WAIT); 1101 async_flag = mp->mnt_flag & MNT_ASYNC; 1102 mp->mnt_flag &= ~MNT_ASYNC; 1103 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1104 if (mp->mnt_syncer != NULL) 1105 vrele(mp->mnt_syncer); 1106 /* 1107 * For forced unmounts, move process cdir/rdir refs on the fs root 1108 * vnode to the covered vnode. For non-forced unmounts we want 1109 * such references to cause an EBUSY error. 1110 */ 1111 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1112 if (mp->mnt_vnodecovered != NULL) 1113 checkdirs(fsrootvp, mp->mnt_vnodecovered); 1114 if (fsrootvp == rootvnode) { 1115 vrele(rootvnode); 1116 rootvnode = NULL; 1117 } 1118 vput(fsrootvp); 1119 } 1120 if (((mp->mnt_flag & MNT_RDONLY) || 1121 (error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) == 0) || 1122 (flags & MNT_FORCE)) { 1123 error = VFS_UNMOUNT(mp, flags, td); 1124 } 1125 vn_finished_write(mp); 1126 if (error) { 1127 /* Undo cdir/rdir and rootvnode changes made above. */ 1128 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1129 if (mp->mnt_vnodecovered != NULL) 1130 checkdirs(mp->mnt_vnodecovered, fsrootvp); 1131 if (rootvnode == NULL) { 1132 rootvnode = fsrootvp; 1133 vref(rootvnode); 1134 } 1135 vput(fsrootvp); 1136 } 1137 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1138 (void) vfs_allocate_syncvnode(mp); 1139 mtx_lock(&mountlist_mtx); 1140 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1141 mp->mnt_flag |= async_flag; 1142 lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, 1143 &mountlist_mtx, td); 1144 if (mp->mnt_kern_flag & MNTK_MWAIT) 1145 wakeup(mp); 1146 return (error); 1147 } 1148 mtx_lock(&mountlist_mtx); 1149 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1150 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 1151 coveredvp->v_mountedhere = NULL; 1152 mtx_unlock(&mountlist_mtx); 1153 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1154 vfs_mount_destroy(mp, td); 1155 if (coveredvp != NULL) 1156 vrele(coveredvp); 1157 return (0); 1158} 1159 1160/* 1161 * Lookup a filesystem type, and if found allocate and initialize 1162 * a mount structure for it. 1163 * 1164 * Devname is usually updated by mount(8) after booting. 1165 */ 1166int 1167vfs_rootmountalloc(fstypename, devname, mpp) 1168 char *fstypename; 1169 char *devname; 1170 struct mount **mpp; 1171{ 1172 struct thread *td = curthread; /* XXX */ 1173 struct vfsconf *vfsp; 1174 struct mount *mp; 1175 int error; 1176 1177 if (fstypename == NULL) 1178 return (ENODEV); 1179 vfsp = vfs_byname(fstypename); 1180 if (vfsp == NULL) 1181 return (ENODEV); 1182 error = vfs_mount_alloc(NULLVP, vfsp, "/", td, &mp); 1183 if (error) 1184 return (error); 1185 mp->mnt_flag |= MNT_RDONLY | MNT_ROOTFS; 1186 strlcpy(mp->mnt_stat.f_mntfromname, devname, MNAMELEN); 1187 *mpp = mp; 1188 return (0); 1189} 1190 1191/* 1192 * Find and mount the root filesystem 1193 */ 1194void 1195vfs_mountroot(void) 1196{ 1197 char *cp; 1198 int error, i; 1199 1200 g_waitidle(); 1201 1202 /* 1203 * The root filesystem information is compiled in, and we are 1204 * booted with instructions to use it. 1205 */ 1206#ifdef ROOTDEVNAME 1207 if ((boothowto & RB_DFLTROOT) && !vfs_mountroot_try(ROOTDEVNAME)) 1208 return; 1209#endif 1210 /* 1211 * We are booted with instructions to prompt for the root filesystem, 1212 * or to use the compiled-in default when it doesn't exist. 1213 */ 1214 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 1215 if (!vfs_mountroot_ask()) 1216 return; 1217 } 1218 1219 /* 1220 * We've been given the generic "use CDROM as root" flag. This is 1221 * necessary because one media may be used in many different 1222 * devices, so we need to search for them. 1223 */ 1224 if (boothowto & RB_CDROM) { 1225 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1226 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1227 return; 1228 } 1229 } 1230 1231 /* 1232 * Try to use the value read by the loader from /etc/fstab, or 1233 * supplied via some other means. This is the preferred 1234 * mechanism. 1235 */ 1236 if ((cp = getenv("vfs.root.mountfrom")) != NULL) { 1237 error = vfs_mountroot_try(cp); 1238 freeenv(cp); 1239 if (!error) 1240 return; 1241 } 1242 1243 /* 1244 * Try values that may have been computed by the machine-dependant 1245 * legacy code. 1246 */ 1247 if (!vfs_mountroot_try(rootdevnames[0])) 1248 return; 1249 if (!vfs_mountroot_try(rootdevnames[1])) 1250 return; 1251 1252 /* 1253 * If we have a compiled-in default, and haven't already tried it, try 1254 * it now. 1255 */ 1256#ifdef ROOTDEVNAME 1257 if (!(boothowto & RB_DFLTROOT)) 1258 if (!vfs_mountroot_try(ROOTDEVNAME)) 1259 return; 1260#endif 1261 1262 /* 1263 * Everything so far has failed, prompt on the console if we haven't 1264 * already tried that. 1265 */ 1266 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 1267 return; 1268 panic("Root mount failed, startup aborted."); 1269} 1270 1271/* 1272 * Mount (mountfrom) as the root filesystem. 1273 */ 1274static int 1275vfs_mountroot_try(char *mountfrom) 1276{ 1277 struct mount *mp; 1278 char *vfsname, *path; 1279 const char *devname; 1280 int error; 1281 char patt[32]; 1282 int s; 1283 1284 vfsname = NULL; 1285 path = NULL; 1286 mp = NULL; 1287 error = EINVAL; 1288 1289 if (mountfrom == NULL) 1290 return (error); /* don't complain */ 1291 1292 s = splcam(); /* Overkill, but annoying without it */ 1293 printf("Mounting root from %s\n", mountfrom); 1294 splx(s); 1295 1296 /* parse vfs name and path */ 1297 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1298 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1299 vfsname[0] = path[0] = 0; 1300 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1301 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1302 goto done; 1303 1304 /* allocate a root mount */ 1305 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 1306 &mp); 1307 if (error != 0) { 1308 printf("Can't allocate root mount for filesystem '%s': %d\n", 1309 vfsname, error); 1310 goto done; 1311 } 1312 1313 /* do our best to set rootdev */ 1314 if (path[0] != '\0' && setrootbyname(path)) 1315 printf("setrootbyname failed\n"); 1316 1317 /* If the root device is a type "memory disk", mount RW */ 1318 if (rootdev != NULL && devsw(rootdev) != NULL) { 1319 devname = devtoname(rootdev); 1320 if (devname[0] == 'm' && devname[1] == 'd') 1321 mp->mnt_flag &= ~MNT_RDONLY; 1322 } 1323 1324 error = VFS_MOUNT(mp, NULL, NULL, NULL, curthread); 1325 1326done: 1327 if (vfsname != NULL) 1328 free(vfsname, M_MOUNT); 1329 if (path != NULL) 1330 free(path, M_MOUNT); 1331 if (error != 0) { 1332 if (mp != NULL) 1333 vfs_mount_destroy(mp, curthread); 1334 printf("Root mount failed: %d\n", error); 1335 } else { 1336 1337 /* register with list of mounted filesystems */ 1338 mtx_lock(&mountlist_mtx); 1339 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1340 mtx_unlock(&mountlist_mtx); 1341 1342 /* sanity check system clock against root fs timestamp */ 1343 inittodr(mp->mnt_time); 1344 vfs_unbusy(mp, curthread); 1345 error = VFS_START(mp, 0, curthread); 1346 } 1347 return (error); 1348} 1349 1350/* 1351 * Spin prompting on the console for a suitable root filesystem 1352 */ 1353static int 1354vfs_mountroot_ask(void) 1355{ 1356 char name[128]; 1357 1358 for(;;) { 1359 printf("\nManual root filesystem specification:\n"); 1360 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1361#if defined(__i386__) || defined(__ia64__) 1362 printf(" eg. ufs:da0s1a\n"); 1363#else 1364 printf(" eg. ufs:/dev/da0a\n"); 1365#endif 1366 printf(" ? List valid disk boot devices\n"); 1367 printf(" <empty line> Abort manual input\n"); 1368 printf("\nmountroot> "); 1369 gets(name); 1370 if (name[0] == '\0') 1371 return (1); 1372 if (name[0] == '?') { 1373 printf("\nList of GEOM managed disk devices:\n "); 1374 g_dev_print(); 1375 continue; 1376 } 1377 if (!vfs_mountroot_try(name)) 1378 return (0); 1379 } 1380} 1381 1382/* 1383 * Local helper function for vfs_mountroot_ask. 1384 */ 1385static void 1386gets(char *cp) 1387{ 1388 char *lp; 1389 int c; 1390 1391 lp = cp; 1392 for (;;) { 1393 printf("%c", c = cngetc() & 0177); 1394 switch (c) { 1395 case -1: 1396 case '\n': 1397 case '\r': 1398 *lp++ = '\0'; 1399 return; 1400 case '\b': 1401 case '\177': 1402 if (lp > cp) { 1403 printf(" \b"); 1404 lp--; 1405 } 1406 continue; 1407 case '#': 1408 lp--; 1409 if (lp < cp) 1410 lp = cp; 1411 continue; 1412 case '@': 1413 case 'u' & 037: 1414 lp = cp; 1415 printf("%c", '\n'); 1416 continue; 1417 default: 1418 *lp++ = c; 1419 } 1420 } 1421} 1422 1423/* 1424 * Convert a given name to the cdev pointer of the device, which is probably 1425 * but not by definition, a disk. Mount a DEVFS (on nothing), look the name 1426 * up, extract the cdev from the vnode and unmount it again. Unfortunately 1427 * we cannot use the vnode directly (because we unmount the DEVFS again) 1428 * so the filesystems still have to do the bdevvp() stunt. 1429 */ 1430struct cdev * 1431getdiskbyname(char *name) 1432{ 1433 char *cp = name; 1434 struct cdev *dev = NULL; 1435 struct thread *td = curthread; 1436 struct vfsconf *vfsp; 1437 struct mount *mp = NULL; 1438 struct vnode *vroot = NULL; 1439 struct nameidata nid; 1440 int error; 1441 1442 if (!bcmp(cp, "/dev/", 5)) 1443 cp += 5; 1444 1445 do { 1446 vfsp = vfs_byname("devfs"); 1447 if (vfsp == NULL) 1448 break; 1449 error = vfs_mount_alloc(NULLVP, vfsp, "/dev", td, &mp); 1450 if (error) 1451 break; 1452 mp->mnt_flag |= MNT_RDONLY; 1453 1454 error = VFS_NMOUNT(mp, NULL, curthread); 1455 if (error) 1456 break; 1457 VFS_START(mp, 0, td); 1458 VFS_ROOT(mp, &vroot, td); 1459 VOP_UNLOCK(vroot, 0, td); 1460 1461 NDINIT(&nid, LOOKUP, NOCACHE|FOLLOW, 1462 UIO_SYSSPACE, cp, curthread); 1463 nid.ni_startdir = vroot; 1464 nid.ni_pathlen = strlen(cp); 1465 nid.ni_cnd.cn_cred = curthread->td_ucred; 1466 nid.ni_cnd.cn_nameptr = cp; 1467 1468 error = lookup(&nid); 1469 if (error) 1470 break; 1471 dev = vn_todev (nid.ni_vp); 1472 NDFREE(&nid, 0); 1473 } while (0); 1474 1475 if (vroot != NULL) 1476 VFS_UNMOUNT(mp, 0, td); 1477 if (mp != NULL) 1478 vfs_mount_destroy(mp, td); 1479 return (dev); 1480} 1481 1482/* 1483 * Set rootdev to match (name), given that we expect it to 1484 * refer to a disk-like device. 1485 */ 1486static int 1487setrootbyname(char *name) 1488{ 1489 struct cdev *diskdev; 1490 1491 diskdev = getdiskbyname(name); 1492 if (diskdev != NULL) { 1493 rootdev = diskdev; 1494 return (0); 1495 } 1496 1497 return (1); 1498} 1499 1500/* Show the struct cdev *for a disk specified by name */ 1501#ifdef DDB 1502DB_SHOW_COMMAND(disk, db_getdiskbyname) 1503{ 1504 struct cdev *dev; 1505 1506 if (modif[0] == '\0') { 1507 db_error("usage: show disk/devicename"); 1508 return; 1509 } 1510 dev = getdiskbyname(modif); 1511 if (dev != NULL) 1512 db_printf("struct cdev *= %p\n", dev); 1513 else 1514 db_printf("No disk device matched.\n"); 1515} 1516#endif 1517 1518/* 1519 * Get a mount option by its name. 1520 * 1521 * Return 0 if the option was found, ENOENT otherwise. 1522 * If len is non-NULL it will be filled with the length 1523 * of the option. If buf is non-NULL, it will be filled 1524 * with the address of the option. 1525 */ 1526int 1527vfs_getopt(opts, name, buf, len) 1528 struct vfsoptlist *opts; 1529 const char *name; 1530 void **buf; 1531 int *len; 1532{ 1533 struct vfsopt *opt; 1534 1535 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1536 1537 TAILQ_FOREACH(opt, opts, link) { 1538 if (strcmp(name, opt->name) == 0) { 1539 if (len != NULL) 1540 *len = opt->len; 1541 if (buf != NULL) 1542 *buf = opt->value; 1543 return (0); 1544 } 1545 } 1546 return (ENOENT); 1547} 1548 1549/* 1550 * Find and copy a mount option. 1551 * 1552 * The size of the buffer has to be specified 1553 * in len, if it is not the same length as the 1554 * mount option, EINVAL is returned. 1555 * Returns ENOENT if the option is not found. 1556 */ 1557int 1558vfs_copyopt(opts, name, dest, len) 1559 struct vfsoptlist *opts; 1560 const char *name; 1561 void *dest; 1562 int len; 1563{ 1564 struct vfsopt *opt; 1565 1566 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1567 1568 TAILQ_FOREACH(opt, opts, link) { 1569 if (strcmp(name, opt->name) == 0) { 1570 if (len != opt->len) 1571 return (EINVAL); 1572 bcopy(opt->value, dest, opt->len); 1573 return (0); 1574 } 1575 } 1576 return (ENOENT); 1577} 1578 1579 1580/* 1581 * This is a helper function for filesystems to traverse their 1582 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1583 */ 1584 1585struct vnode * 1586__mnt_vnode_next(struct vnode **nvp, struct mount *mp) 1587{ 1588 struct vnode *vp; 1589 1590 mtx_assert(&mp->mnt_mtx, MA_OWNED); 1591 vp = *nvp; 1592 /* Check if we are done */ 1593 if (vp == NULL) 1594 return (NULL); 1595 /* If our next vnode is no longer ours, start over */ 1596 if (vp->v_mount != mp) 1597 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1598 /* Save pointer to next vnode in list */ 1599 if (vp != NULL) 1600 *nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1601 else 1602 *nvp = NULL; 1603 return (vp); 1604} 1605