vfs_mount.c revision 134827
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 134827 2004-09-05 22:24:28Z alfred $"); 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(const 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}; 151struct cdev *rootdev = NULL; 152#ifdef ROOTDEVNAME 153const char *ctrootdevname = ROOTDEVNAME; 154#else 155const char *ctrootdevname = NULL; 156#endif 157 158/* 159 * Has to be dynamic as the value of rootdev can change; however, it can't 160 * change after the root is mounted, so a user process can't access this 161 * sysctl until after the value is unchangeable. 162 */ 163static int 164sysctl_rootdev(SYSCTL_HANDLER_ARGS) 165{ 166 int error; 167 168 /* _RD prevents this from happening. */ 169 KASSERT(req->newptr == NULL, ("Attempt to change root device name")); 170 171 if (rootdev != NULL) 172 error = sysctl_handle_string(oidp, rootdev->si_name, 0, req); 173 else 174 error = sysctl_handle_string(oidp, "", 0, req); 175 176 return (error); 177} 178 179SYSCTL_PROC(_kern, OID_AUTO, rootdev, CTLTYPE_STRING | CTLFLAG_RD, 180 0, 0, sysctl_rootdev, "A", "Root file system device"); 181 182/* Remove one mount option. */ 183static void 184vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 185{ 186 187 TAILQ_REMOVE(opts, opt, link); 188 free(opt->name, M_MOUNT); 189 if (opt->value != NULL) 190 free(opt->value, M_MOUNT); 191#ifdef INVARIANTS 192 else if (opt->len != 0) 193 panic("%s: mount option with NULL value but length != 0", 194 __func__); 195#endif 196 free(opt, M_MOUNT); 197} 198 199/* Release all resources related to the mount options. */ 200static void 201vfs_freeopts(struct vfsoptlist *opts) 202{ 203 struct vfsopt *opt; 204 205 while (!TAILQ_EMPTY(opts)) { 206 opt = TAILQ_FIRST(opts); 207 vfs_freeopt(opts, opt); 208 } 209 free(opts, M_MOUNT); 210} 211 212/* 213 * Check if options are equal (with or without the "no" prefix). 214 */ 215static int 216vfs_equalopts(const char *opt1, const char *opt2) 217{ 218 219 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 220 if (strcmp(opt1, opt2) == 0) 221 return (1); 222 /* "noopt" vs. "opt" */ 223 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 224 return (1); 225 /* "opt" vs. "noopt" */ 226 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 227 return (1); 228 return (0); 229} 230 231/* 232 * If a mount option is specified several times, 233 * (with or without the "no" prefix) only keep 234 * the last occurence of it. 235 */ 236static void 237vfs_sanitizeopts(struct vfsoptlist *opts) 238{ 239 struct vfsopt *opt, *opt2, *tmp; 240 241 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 242 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 243 while (opt2 != NULL) { 244 if (vfs_equalopts(opt->name, opt2->name)) { 245 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 246 vfs_freeopt(opts, opt2); 247 opt2 = tmp; 248 } else { 249 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 250 } 251 } 252 } 253} 254 255/* 256 * Build a linked list of mount options from a struct uio. 257 */ 258static int 259vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 260{ 261 struct vfsoptlist *opts; 262 struct vfsopt *opt; 263 size_t memused; 264 unsigned int i, iovcnt; 265 int error, namelen, optlen; 266 267 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 268 TAILQ_INIT(opts); 269 memused = 0; 270 iovcnt = auio->uio_iovcnt; 271 for (i = 0; i < iovcnt; i += 2) { 272 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 273 namelen = auio->uio_iov[i].iov_len; 274 optlen = auio->uio_iov[i + 1].iov_len; 275 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 276 opt->value = NULL; 277 opt->len = 0; 278 279 /* 280 * Do this early, so jumps to "bad" will free the current 281 * option. 282 */ 283 TAILQ_INSERT_TAIL(opts, opt, link); 284 memused += sizeof(struct vfsopt) + optlen + namelen; 285 286 /* 287 * Avoid consuming too much memory, and attempts to overflow 288 * memused. 289 */ 290 if (memused > VFS_MOUNTARG_SIZE_MAX || 291 optlen > VFS_MOUNTARG_SIZE_MAX || 292 namelen > VFS_MOUNTARG_SIZE_MAX) { 293 error = EINVAL; 294 goto bad; 295 } 296 297 if (auio->uio_segflg == UIO_SYSSPACE) { 298 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 299 } else { 300 error = copyin(auio->uio_iov[i].iov_base, opt->name, 301 namelen); 302 if (error) 303 goto bad; 304 } 305 /* Ensure names are null-terminated strings. */ 306 if (opt->name[namelen - 1] != '\0') { 307 error = EINVAL; 308 goto bad; 309 } 310 if (optlen != 0) { 311 opt->len = optlen; 312 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 313 if (auio->uio_segflg == UIO_SYSSPACE) { 314 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 315 optlen); 316 } else { 317 error = copyin(auio->uio_iov[i + 1].iov_base, 318 opt->value, optlen); 319 if (error) 320 goto bad; 321 } 322 } 323 } 324 vfs_sanitizeopts(opts); 325 *options = opts; 326 return (0); 327bad: 328 vfs_freeopts(opts); 329 return (error); 330} 331 332/* 333 * Merge the old mount options with the new ones passed 334 * in the MNT_UPDATE case. 335 */ 336static void 337vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 338{ 339 struct vfsopt *opt, *opt2, *new; 340 341 TAILQ_FOREACH(opt, opts, link) { 342 /* 343 * Check that this option hasn't been redefined 344 * nor cancelled with a "no" mount option. 345 */ 346 opt2 = TAILQ_FIRST(toopts); 347 while (opt2 != NULL) { 348 if (strcmp(opt2->name, opt->name) == 0) 349 goto next; 350 if (strncmp(opt2->name, "no", 2) == 0 && 351 strcmp(opt2->name + 2, opt->name) == 0) { 352 vfs_freeopt(toopts, opt2); 353 goto next; 354 } 355 opt2 = TAILQ_NEXT(opt2, link); 356 } 357 /* We want this option, duplicate it. */ 358 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 359 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 360 strcpy(new->name, opt->name); 361 if (opt->len != 0) { 362 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 363 bcopy(opt->value, new->value, opt->len); 364 } else { 365 new->value = NULL; 366 } 367 new->len = opt->len; 368 TAILQ_INSERT_TAIL(toopts, new, link); 369next: 370 continue; 371 } 372} 373 374/* 375 * New mount API. 376 */ 377int 378nmount(td, uap) 379 struct thread *td; 380 struct nmount_args /* { 381 struct iovec *iovp; 382 unsigned int iovcnt; 383 int flags; 384 } */ *uap; 385{ 386 struct uio *auio; 387 struct iovec *iov; 388 unsigned int i; 389 int error; 390 u_int iovcnt; 391 392 iovcnt = uap->iovcnt; 393 /* 394 * Check that we have an even number of iovec's 395 * and that we have at least two options. 396 */ 397 if ((iovcnt & 1) || (iovcnt < 4)) 398 return (EINVAL); 399 error = copyinuio(uap->iovp, iovcnt, &auio); 400 if (error) 401 return (error); 402 iov = auio->uio_iov; 403 for (i = 0; i < iovcnt; i++) { 404 if (iov->iov_len > MMAXOPTIONLEN) { 405 free(auio, M_IOV); 406 return (EINVAL); 407 } 408 iov++; 409 } 410 error = vfs_donmount(td, uap->flags, auio); 411 free(auio, M_IOV); 412 return (error); 413} 414 415int 416kernel_mount(struct iovec *iovp, u_int iovcnt, int flags) 417{ 418 struct uio auio; 419 int error; 420 421 /* 422 * Check that we have an even number of iovec's 423 * and that we have at least two options. 424 */ 425 if ((iovcnt & 1) || (iovcnt < 4)) 426 return (EINVAL); 427 428 auio.uio_iov = iovp; 429 auio.uio_iovcnt = iovcnt; 430 auio.uio_segflg = UIO_SYSSPACE; 431 432 error = vfs_donmount(curthread, flags, &auio); 433 return (error); 434} 435 436int 437kernel_vmount(int flags, ...) 438{ 439 struct iovec *iovp; 440 struct uio auio; 441 va_list ap; 442 u_int iovcnt, iovlen, len; 443 const char *cp; 444 char *buf, *pos; 445 size_t n; 446 int error, i; 447 448 len = 0; 449 va_start(ap, flags); 450 for (iovcnt = 0; (cp = va_arg(ap, const char *)) != NULL; iovcnt++) 451 len += strlen(cp) + 1; 452 va_end(ap); 453 454 if (iovcnt < 4 || iovcnt & 1) 455 return (EINVAL); 456 457 iovlen = iovcnt * sizeof (struct iovec); 458 MALLOC(iovp, struct iovec *, iovlen, M_MOUNT, M_WAITOK); 459 MALLOC(buf, char *, len, M_MOUNT, M_WAITOK); 460 pos = buf; 461 va_start(ap, flags); 462 for (i = 0; i < iovcnt; i++) { 463 cp = va_arg(ap, const char *); 464 copystr(cp, pos, len - (pos - buf), &n); 465 iovp[i].iov_base = pos; 466 iovp[i].iov_len = n; 467 pos += n; 468 } 469 va_end(ap); 470 471 auio.uio_iov = iovp; 472 auio.uio_iovcnt = iovcnt; 473 auio.uio_segflg = UIO_SYSSPACE; 474 475 error = vfs_donmount(curthread, flags, &auio); 476 FREE(iovp, M_MOUNT); 477 FREE(buf, M_MOUNT); 478 return (error); 479} 480 481/* 482 * Allocate and initialize the mount point struct. 483 */ 484static int 485vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 486 const char *fspath, struct thread *td, struct mount **mpp) 487{ 488 struct mount *mp; 489 490 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 491 TAILQ_INIT(&mp->mnt_nvnodelist); 492 mp->mnt_nvnodelistsize = 0; 493 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 494 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 495 vfs_busy(mp, LK_NOWAIT, 0, td); 496 mp->mnt_op = vfsp->vfc_vfsops; 497 mp->mnt_vfc = vfsp; 498 vfsp->vfc_refcount++; 499 mp->mnt_stat.f_type = vfsp->vfc_typenum; 500 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 501 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 502 mp->mnt_vnodecovered = vp; 503 mp->mnt_cred = crdup(td->td_ucred); 504 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 505 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 506 mp->mnt_iosize_max = DFLTPHYS; 507#ifdef MAC 508 mac_init_mount(mp); 509 mac_create_mount(td->td_ucred, mp); 510#endif 511 *mpp = mp; 512 return (0); 513} 514 515/* 516 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 517 */ 518void 519vfs_mount_destroy(struct mount *mp, struct thread *td) 520{ 521 522 mp->mnt_vfc->vfc_refcount--; 523 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 524 panic("unmount: dangling vnode"); 525 vfs_unbusy(mp,td); 526 lockdestroy(&mp->mnt_lock); 527 mtx_destroy(&mp->mnt_mtx); 528 if (mp->mnt_kern_flag & MNTK_MWAIT) 529 wakeup(mp); 530#ifdef MAC 531 mac_destroy_mount(mp); 532#endif 533 if (mp->mnt_opt != NULL) 534 vfs_freeopts(mp->mnt_opt); 535 crfree(mp->mnt_cred); 536 free(mp, M_MOUNT); 537} 538 539static int 540vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 541{ 542 struct vfsoptlist *optlist; 543 char *fstype, *fspath; 544 int error, fstypelen, fspathlen; 545 546 error = vfs_buildopts(fsoptions, &optlist); 547 if (error) 548 return (error); 549 550 /* 551 * We need these two options before the others, 552 * and they are mandatory for any filesystem. 553 * Ensure they are NUL terminated as well. 554 */ 555 fstypelen = 0; 556 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 557 if (error || fstype[fstypelen - 1] != '\0') { 558 error = EINVAL; 559 goto bail; 560 } 561 fspathlen = 0; 562 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 563 if (error || fspath[fspathlen - 1] != '\0') { 564 error = EINVAL; 565 goto bail; 566 } 567 568 /* 569 * Be ultra-paranoid about making sure the type and fspath 570 * variables will fit in our mp buffers, including the 571 * terminating NUL. 572 */ 573 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 574 error = ENAMETOOLONG; 575 goto bail; 576 } 577 578 error = vfs_domount(td, fstype, fspath, fsflags, optlist, 0); 579bail: 580 if (error) 581 vfs_freeopts(optlist); 582 return (error); 583} 584 585/* 586 * Old mount API. 587 */ 588#ifndef _SYS_SYSPROTO_H_ 589struct mount_args { 590 char *type; 591 char *path; 592 int flags; 593 caddr_t data; 594}; 595#endif 596/* ARGSUSED */ 597int 598mount(td, uap) 599 struct thread *td; 600 struct mount_args /* { 601 char *type; 602 char *path; 603 int flags; 604 caddr_t data; 605 } */ *uap; 606{ 607 char *fstype; 608 char *fspath; 609 int error; 610 611 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 612 fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK); 613 614 /* 615 * vfs_mount() actually takes a kernel string for `type' and 616 * `path' now, so extract them. 617 */ 618 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 619 if (error == 0) 620 error = copyinstr(uap->path, fspath, MNAMELEN, NULL); 621 if (error == 0) 622 error = vfs_domount(td, fstype, fspath, uap->flags, 623 uap->data, 1); 624 free(fstype, M_TEMP); 625 free(fspath, M_TEMP); 626 return (error); 627} 628 629/* 630 * vfs_mount(): actually attempt a filesystem mount. 631 * 632 * This routine is designed to be a "generic" entry point for routines 633 * that wish to mount a filesystem. All parameters except `fsdata' are 634 * pointers into kernel space. `fsdata' is currently still a pointer 635 * into userspace. 636 */ 637int 638vfs_mount(td, fstype, fspath, fsflags, fsdata) 639 struct thread *td; 640 const char *fstype; 641 char *fspath; 642 int fsflags; 643 void *fsdata; 644{ 645 646 return (vfs_domount(td, fstype, fspath, fsflags, fsdata, 1)); 647} 648 649/* 650 * vfs_domount(): actually attempt a filesystem mount. 651 */ 652static int 653vfs_domount( 654 struct thread *td, /* Flags common to all filesystems. */ 655 const char *fstype, /* Filesystem type. */ 656 char *fspath, /* Mount path. */ 657 int fsflags, /* Flags common to all filesystems. */ 658 void *fsdata, /* Options local to the filesystem. */ 659 int compat /* Invocation from compat syscall. */ 660 ) 661{ 662 linker_file_t lf; 663 struct vnode *vp; 664 struct mount *mp; 665 struct vfsconf *vfsp; 666 int error, flag = 0, kern_flag = 0; 667 struct vattr va; 668 struct nameidata nd; 669 670 /* 671 * Be ultra-paranoid about making sure the type and fspath 672 * variables will fit in our mp buffers, including the 673 * terminating NUL. 674 */ 675 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 676 return (ENAMETOOLONG); 677 678 if (jailed(td->td_ucred)) 679 return (EPERM); 680 if (usermount == 0) { 681 if ((error = suser(td)) != 0) 682 return (error); 683 } 684 685 /* 686 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 687 */ 688 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 689 if ((error = suser(td)) != 0) 690 return (error); 691 } 692 /* 693 * Silently enforce MNT_NODEV, MNT_NOSUID and MNT_USER for 694 * unprivileged users. 695 */ 696 if (suser(td) != 0) 697 fsflags |= MNT_NODEV | MNT_NOSUID | MNT_USER; 698 /* 699 * Get vnode to be covered 700 */ 701 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 702 if ((error = namei(&nd)) != 0) 703 return (error); 704 NDFREE(&nd, NDF_ONLY_PNBUF); 705 vp = nd.ni_vp; 706 if (fsflags & MNT_UPDATE) { 707 if ((vp->v_vflag & VV_ROOT) == 0) { 708 vput(vp); 709 return (EINVAL); 710 } 711 mp = vp->v_mount; 712 flag = mp->mnt_flag; 713 kern_flag = mp->mnt_kern_flag; 714 /* 715 * We only allow the filesystem to be reloaded if it 716 * is currently mounted read-only. 717 */ 718 if ((fsflags & MNT_RELOAD) && 719 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 720 vput(vp); 721 return (EOPNOTSUPP); /* Needs translation */ 722 } 723 /* 724 * Only privileged root, or (if MNT_USER is set) the user that 725 * did the original mount is permitted to update it. 726 */ 727 error = vfs_suser(mp, td); 728 if (error) { 729 vput(vp); 730 return (error); 731 } 732 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 733 vput(vp); 734 return (EBUSY); 735 } 736 VI_LOCK(vp); 737 if ((vp->v_iflag & VI_MOUNT) != 0 || 738 vp->v_mountedhere != NULL) { 739 VI_UNLOCK(vp); 740 vfs_unbusy(mp, td); 741 vput(vp); 742 return (EBUSY); 743 } 744 vp->v_iflag |= VI_MOUNT; 745 VI_UNLOCK(vp); 746 mp->mnt_flag |= fsflags & 747 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT); 748 VOP_UNLOCK(vp, 0, td); 749 if (compat == 0) { 750 mp->mnt_optnew = fsdata; 751 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 752 } 753 } else { 754 /* 755 * If the user is not root, ensure that they own the directory 756 * onto which we are attempting to mount. 757 */ 758 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 759 if (error) { 760 vput(vp); 761 return (error); 762 } 763 if (va.va_uid != td->td_ucred->cr_uid) { 764 if ((error = suser(td)) != 0) { 765 vput(vp); 766 return (error); 767 } 768 } 769 if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) { 770 vput(vp); 771 return (error); 772 } 773 if (vp->v_type != VDIR) { 774 vput(vp); 775 return (ENOTDIR); 776 } 777 vfsp = vfs_byname(fstype); 778 if (vfsp == NULL) { 779 /* Only load modules for root (very important!). */ 780 if ((error = suser(td)) != 0) { 781 vput(vp); 782 return (error); 783 } 784 error = securelevel_gt(td->td_ucred, 0); 785 if (error) { 786 vput(vp); 787 return (error); 788 } 789 error = linker_load_module(NULL, fstype, NULL, NULL, &lf); 790 if (error || lf == NULL) { 791 vput(vp); 792 if (lf == NULL) 793 error = ENODEV; 794 return (error); 795 } 796 lf->userrefs++; 797 /* Look up again to see if the VFS was loaded. */ 798 vfsp = vfs_byname(fstype); 799 if (vfsp == NULL) { 800 lf->userrefs--; 801 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 802 vput(vp); 803 return (ENODEV); 804 } 805 } 806 VI_LOCK(vp); 807 if ((vp->v_iflag & VI_MOUNT) != 0 || 808 vp->v_mountedhere != NULL) { 809 VI_UNLOCK(vp); 810 vput(vp); 811 return (EBUSY); 812 } 813 vp->v_iflag |= VI_MOUNT; 814 VI_UNLOCK(vp); 815 816 /* 817 * Allocate and initialize the filesystem. 818 */ 819 error = vfs_mount_alloc(vp, vfsp, fspath, td, &mp); 820 if (error) { 821 vput(vp); 822 return (error); 823 } 824 VOP_UNLOCK(vp, 0, td); 825 826 /* XXXMAC: pass to vfs_mount_alloc? */ 827 if (compat == 0) 828 mp->mnt_optnew = fsdata; 829 } 830 /* 831 * Check if the fs implements the type VFS_[O]MOUNT() 832 * function we are looking for. 833 */ 834 if ((compat == 0) == (mp->mnt_op->vfs_omount != NULL)) { 835 printf("%s doesn't support the %s mount syscall\n", 836 mp->mnt_vfc->vfc_name, compat ? "old" : "new"); 837 VI_LOCK(vp); 838 vp->v_iflag &= ~VI_MOUNT; 839 VI_UNLOCK(vp); 840 if (mp->mnt_flag & MNT_UPDATE) 841 vfs_unbusy(mp, td); 842 else 843 vfs_mount_destroy(mp, td); 844 vrele(vp); 845 return (EOPNOTSUPP); 846 } 847 848 /* 849 * Set the mount level flags. 850 */ 851 if (fsflags & MNT_RDONLY) 852 mp->mnt_flag |= MNT_RDONLY; 853 else if (mp->mnt_flag & MNT_RDONLY) 854 mp->mnt_kern_flag |= MNTK_WANTRDWR; 855 mp->mnt_flag &=~ MNT_UPDATEMASK; 856 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE); 857 /* 858 * Mount the filesystem. 859 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 860 * get. No freeing of cn_pnbuf. 861 */ 862 if (compat) 863 error = VFS_OMOUNT(mp, fspath, fsdata, td); 864 else 865 error = VFS_MOUNT(mp, td); 866 if (!error) { 867 if (mp->mnt_opt != NULL) 868 vfs_freeopts(mp->mnt_opt); 869 mp->mnt_opt = mp->mnt_optnew; 870 } 871 /* 872 * Prevent external consumers of mount options from reading 873 * mnt_optnew. 874 */ 875 mp->mnt_optnew = NULL; 876 if (mp->mnt_flag & MNT_UPDATE) { 877 if (mp->mnt_kern_flag & MNTK_WANTRDWR) 878 mp->mnt_flag &= ~MNT_RDONLY; 879 mp->mnt_flag &= 880 ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 881 mp->mnt_kern_flag &= ~MNTK_WANTRDWR; 882 if (error) { 883 mp->mnt_flag = flag; 884 mp->mnt_kern_flag = kern_flag; 885 } 886 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 887 if (mp->mnt_syncer == NULL) 888 error = vfs_allocate_syncvnode(mp); 889 } else { 890 if (mp->mnt_syncer != NULL) 891 vrele(mp->mnt_syncer); 892 mp->mnt_syncer = NULL; 893 } 894 vfs_unbusy(mp, td); 895 VI_LOCK(vp); 896 vp->v_iflag &= ~VI_MOUNT; 897 VI_UNLOCK(vp); 898 vrele(vp); 899 return (error); 900 } 901 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 902 /* 903 * Put the new filesystem on the mount list after root. 904 */ 905 cache_purge(vp); 906 if (!error) { 907 struct vnode *newdp; 908 909 VI_LOCK(vp); 910 vp->v_iflag &= ~VI_MOUNT; 911 VI_UNLOCK(vp); 912 vp->v_mountedhere = mp; 913 mtx_lock(&mountlist_mtx); 914 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 915 mtx_unlock(&mountlist_mtx); 916 vfs_event_signal(NULL, VQ_MOUNT, 0); 917 if (VFS_ROOT(mp, &newdp, td)) 918 panic("mount: lost mount"); 919 checkdirs(vp, newdp); 920 vput(newdp); 921 VOP_UNLOCK(vp, 0, td); 922 if ((mp->mnt_flag & MNT_RDONLY) == 0) 923 error = vfs_allocate_syncvnode(mp); 924 vfs_unbusy(mp, td); 925 if (error || (error = VFS_START(mp, 0, td)) != 0) 926 vrele(vp); 927 } else { 928 VI_LOCK(vp); 929 vp->v_iflag &= ~VI_MOUNT; 930 VI_UNLOCK(vp); 931 vfs_mount_destroy(mp, td); 932 vput(vp); 933 } 934 return (error); 935} 936 937/* 938 * Scan all active processes to see if any of them have a current 939 * or root directory of `olddp'. If so, replace them with the new 940 * mount point. 941 */ 942static void 943checkdirs(olddp, newdp) 944 struct vnode *olddp, *newdp; 945{ 946 struct filedesc *fdp; 947 struct proc *p; 948 int nrele; 949 950 if (vrefcnt(olddp) == 1) 951 return; 952 sx_slock(&allproc_lock); 953 LIST_FOREACH(p, &allproc, p_list) { 954 mtx_lock(&fdesc_mtx); 955 fdp = p->p_fd; 956 if (fdp == NULL) { 957 mtx_unlock(&fdesc_mtx); 958 continue; 959 } 960 nrele = 0; 961 FILEDESC_LOCK(fdp); 962 if (fdp->fd_cdir == olddp) { 963 VREF(newdp); 964 fdp->fd_cdir = newdp; 965 nrele++; 966 } 967 if (fdp->fd_rdir == olddp) { 968 VREF(newdp); 969 fdp->fd_rdir = newdp; 970 nrele++; 971 } 972 FILEDESC_UNLOCK(fdp); 973 mtx_unlock(&fdesc_mtx); 974 while (nrele--) 975 vrele(olddp); 976 } 977 sx_sunlock(&allproc_lock); 978 if (rootvnode == olddp) { 979 vrele(rootvnode); 980 VREF(newdp); 981 rootvnode = newdp; 982 } 983} 984 985/* 986 * Unmount a filesystem. 987 * 988 * Note: unmount takes a path to the vnode mounted on as argument, 989 * not special file (as before). 990 */ 991#ifndef _SYS_SYSPROTO_H_ 992struct unmount_args { 993 char *path; 994 int flags; 995}; 996#endif 997/* ARGSUSED */ 998int 999unmount(td, uap) 1000 struct thread *td; 1001 register struct unmount_args /* { 1002 char *path; 1003 int flags; 1004 } */ *uap; 1005{ 1006 struct mount *mp; 1007 char *pathbuf; 1008 int error, id0, id1; 1009 1010 if (jailed(td->td_ucred)) 1011 return (EPERM); 1012 if (usermount == 0) { 1013 if ((error = suser(td)) != 0) 1014 return (error); 1015 } 1016 1017 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1018 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1019 if (error) { 1020 free(pathbuf, M_TEMP); 1021 return (error); 1022 } 1023 if (uap->flags & MNT_BYFSID) { 1024 /* Decode the filesystem ID. */ 1025 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1026 free(pathbuf, M_TEMP); 1027 return (EINVAL); 1028 } 1029 1030 mtx_lock(&mountlist_mtx); 1031 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1032 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1033 mp->mnt_stat.f_fsid.val[1] == id1) 1034 break; 1035 } 1036 mtx_unlock(&mountlist_mtx); 1037 } else { 1038 mtx_lock(&mountlist_mtx); 1039 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1040 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1041 break; 1042 } 1043 mtx_unlock(&mountlist_mtx); 1044 } 1045 free(pathbuf, M_TEMP); 1046 if (mp == NULL) { 1047 /* 1048 * Previously we returned ENOENT for a nonexistent path and 1049 * EINVAL for a non-mountpoint. We cannot tell these apart 1050 * now, so in the !MNT_BYFSID case return the more likely 1051 * EINVAL for compatibility. 1052 */ 1053 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1054 } 1055 1056 /* 1057 * Only privileged root, or (if MNT_USER is set) the user that did the 1058 * original mount is permitted to unmount this filesystem. 1059 */ 1060 error = vfs_suser(mp, td); 1061 if (error) 1062 return (error); 1063 1064 /* 1065 * Don't allow unmounting the root filesystem. 1066 */ 1067 if (mp->mnt_flag & MNT_ROOTFS) 1068 return (EINVAL); 1069 return (dounmount(mp, uap->flags, td)); 1070} 1071 1072/* 1073 * Do the actual filesystem unmount. 1074 */ 1075int 1076dounmount(mp, flags, td) 1077 struct mount *mp; 1078 int flags; 1079 struct thread *td; 1080{ 1081 struct vnode *coveredvp, *fsrootvp; 1082 int error; 1083 int async_flag; 1084 1085 mtx_lock(&mountlist_mtx); 1086 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1087 mtx_unlock(&mountlist_mtx); 1088 return (EBUSY); 1089 } 1090 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1091 /* Allow filesystems to detect that a forced unmount is in progress. */ 1092 if (flags & MNT_FORCE) 1093 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1094 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1095 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); 1096 if (error) { 1097 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1098 if (mp->mnt_kern_flag & MNTK_MWAIT) 1099 wakeup(mp); 1100 return (error); 1101 } 1102 vn_start_write(NULL, &mp, V_WAIT); 1103 1104 if (mp->mnt_flag & MNT_EXPUBLIC) 1105 vfs_setpublicfs(NULL, NULL, NULL); 1106 1107 vfs_msync(mp, MNT_WAIT); 1108 async_flag = mp->mnt_flag & MNT_ASYNC; 1109 mp->mnt_flag &= ~MNT_ASYNC; 1110 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1111 if (mp->mnt_syncer != NULL) 1112 vrele(mp->mnt_syncer); 1113 /* 1114 * For forced unmounts, move process cdir/rdir refs on the fs root 1115 * vnode to the covered vnode. For non-forced unmounts we want 1116 * such references to cause an EBUSY error. 1117 */ 1118 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1119 if (mp->mnt_vnodecovered != NULL) 1120 checkdirs(fsrootvp, mp->mnt_vnodecovered); 1121 if (fsrootvp == rootvnode) { 1122 vrele(rootvnode); 1123 rootvnode = NULL; 1124 } 1125 vput(fsrootvp); 1126 } 1127 if (((mp->mnt_flag & MNT_RDONLY) || 1128 (error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) == 0) || 1129 (flags & MNT_FORCE)) { 1130 error = VFS_UNMOUNT(mp, flags, td); 1131 } 1132 vn_finished_write(mp); 1133 if (error) { 1134 /* Undo cdir/rdir and rootvnode changes made above. */ 1135 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1136 if (mp->mnt_vnodecovered != NULL) 1137 checkdirs(mp->mnt_vnodecovered, fsrootvp); 1138 if (rootvnode == NULL) { 1139 rootvnode = fsrootvp; 1140 vref(rootvnode); 1141 } 1142 vput(fsrootvp); 1143 } 1144 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1145 (void) vfs_allocate_syncvnode(mp); 1146 mtx_lock(&mountlist_mtx); 1147 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1148 mp->mnt_flag |= async_flag; 1149 lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, 1150 &mountlist_mtx, td); 1151 if (mp->mnt_kern_flag & MNTK_MWAIT) 1152 wakeup(mp); 1153 return (error); 1154 } 1155 mtx_lock(&mountlist_mtx); 1156 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1157 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 1158 coveredvp->v_mountedhere = NULL; 1159 mtx_unlock(&mountlist_mtx); 1160 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1161 vfs_mount_destroy(mp, td); 1162 if (coveredvp != NULL) 1163 vrele(coveredvp); 1164 return (0); 1165} 1166 1167/* 1168 * Lookup a filesystem type, and if found allocate and initialize 1169 * a mount structure for it. 1170 * 1171 * Devname is usually updated by mount(8) after booting. 1172 */ 1173int 1174vfs_rootmountalloc(fstypename, devname, mpp) 1175 char *fstypename; 1176 char *devname; 1177 struct mount **mpp; 1178{ 1179 struct thread *td = curthread; /* XXX */ 1180 struct vfsconf *vfsp; 1181 struct mount *mp; 1182 int error; 1183 1184 if (fstypename == NULL) 1185 return (ENODEV); 1186 vfsp = vfs_byname(fstypename); 1187 if (vfsp == NULL) 1188 return (ENODEV); 1189 error = vfs_mount_alloc(NULLVP, vfsp, "/", td, &mp); 1190 if (error) 1191 return (error); 1192 mp->mnt_flag |= MNT_RDONLY | MNT_ROOTFS; 1193 strlcpy(mp->mnt_stat.f_mntfromname, devname, MNAMELEN); 1194 *mpp = mp; 1195 return (0); 1196} 1197 1198/* 1199 * Find and mount the root filesystem 1200 */ 1201void 1202vfs_mountroot(void) 1203{ 1204 char *cp; 1205 int error, i, asked = 0; 1206 1207 1208 /* 1209 * Wait for GEOM to settle down 1210 */ 1211 g_waitidle(); 1212 1213 /* 1214 * We are booted with instructions to prompt for the root filesystem. 1215 */ 1216 if (boothowto & RB_ASKNAME) { 1217 if (!vfs_mountroot_ask()) 1218 return; 1219 asked = 1; 1220 } 1221 1222 /* 1223 * The root filesystem information is compiled in, and we are 1224 * booted with instructions to use it. 1225 */ 1226 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1227 if (!vfs_mountroot_try(ctrootdevname)) 1228 return; 1229 ctrootdevname = NULL; 1230 } 1231 1232 /* 1233 * We've been given the generic "use CDROM as root" flag. This is 1234 * necessary because one media may be used in many different 1235 * devices, so we need to search for them. 1236 */ 1237 if (boothowto & RB_CDROM) { 1238 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1239 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1240 return; 1241 } 1242 } 1243 1244 /* 1245 * Try to use the value read by the loader from /etc/fstab, or 1246 * supplied via some other means. This is the preferred 1247 * mechanism. 1248 */ 1249 cp = getenv("vfs.root.mountfrom"); 1250 if (cp != NULL) { 1251 error = vfs_mountroot_try(cp); 1252 freeenv(cp); 1253 if (!error) 1254 return; 1255 } 1256 1257 /* 1258 * Try values that may have been computed by code during boot 1259 */ 1260 if (!vfs_mountroot_try(rootdevnames[0])) 1261 return; 1262 if (!vfs_mountroot_try(rootdevnames[1])) 1263 return; 1264 1265 /* 1266 * If we (still) have a compiled-in default, try it. 1267 */ 1268 if (ctrootdevname != NULL) 1269 if (!vfs_mountroot_try(ctrootdevname)) 1270 return; 1271 1272 /* 1273 * Everything so far has failed, prompt on the console if we haven't 1274 * already tried that. 1275 */ 1276 if (!asked) 1277 if (!vfs_mountroot_ask()) 1278 return; 1279 panic("Root mount failed, startup aborted."); 1280} 1281 1282/* 1283 * Mount (mountfrom) as the root filesystem. 1284 */ 1285static int 1286vfs_mountroot_try(const char *mountfrom) 1287{ 1288 struct mount *mp; 1289 char *vfsname, *path; 1290 const char *devname; 1291 int error; 1292 char patt[32]; 1293 int s; 1294 1295 vfsname = NULL; 1296 path = NULL; 1297 mp = NULL; 1298 error = EINVAL; 1299 1300 if (mountfrom == NULL) 1301 return (error); /* don't complain */ 1302 1303 s = splcam(); /* Overkill, but annoying without it */ 1304 printf("Mounting root from %s\n", mountfrom); 1305 splx(s); 1306 1307 /* parse vfs name and path */ 1308 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1309 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1310 vfsname[0] = path[0] = 0; 1311 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1312 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1313 goto done; 1314 1315 /* allocate a root mount */ 1316 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 1317 &mp); 1318 if (error != 0) { 1319 printf("Can't allocate root mount for filesystem '%s': %d\n", 1320 vfsname, error); 1321 goto done; 1322 } 1323 1324 /* 1325 * do our best to set rootdev 1326 * XXX: This does not belong here! 1327 */ 1328 if (path[0] != '\0') { 1329 struct cdev *diskdev; 1330 diskdev = getdiskbyname(path); 1331 if (diskdev != NULL) 1332 rootdev = diskdev; 1333 else 1334 printf("setrootbyname failed\n"); 1335 } 1336 1337 /* If the root device is a type "memory disk", mount RW */ 1338 if (rootdev != NULL && devsw(rootdev) != NULL) { 1339 devname = devtoname(rootdev); 1340 if (devname[0] == 'm' && devname[1] == 'd') 1341 mp->mnt_flag &= ~MNT_RDONLY; 1342 } 1343 1344 error = VFS_OMOUNT(mp, NULL, NULL, curthread); 1345 1346done: 1347 if (vfsname != NULL) 1348 free(vfsname, M_MOUNT); 1349 if (path != NULL) 1350 free(path, M_MOUNT); 1351 if (error != 0) { 1352 if (mp != NULL) 1353 vfs_mount_destroy(mp, curthread); 1354 printf("Root mount failed: %d\n", error); 1355 } else { 1356 1357 /* register with list of mounted filesystems */ 1358 mtx_lock(&mountlist_mtx); 1359 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1360 mtx_unlock(&mountlist_mtx); 1361 1362 /* sanity check system clock against root fs timestamp */ 1363 inittodr(mp->mnt_time); 1364 vfs_unbusy(mp, curthread); 1365 error = VFS_START(mp, 0, curthread); 1366 } 1367 return (error); 1368} 1369 1370/* 1371 * Spin prompting on the console for a suitable root filesystem 1372 */ 1373static int 1374vfs_mountroot_ask(void) 1375{ 1376 char name[128]; 1377 1378 for(;;) { 1379 printf("\nManual root filesystem specification:\n"); 1380 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1381#if defined(__i386__) || defined(__ia64__) 1382 printf(" eg. ufs:da0s1a\n"); 1383#else 1384 printf(" eg. ufs:/dev/da0a\n"); 1385#endif 1386 printf(" ? List valid disk boot devices\n"); 1387 printf(" <empty line> Abort manual input\n"); 1388 printf("\nmountroot> "); 1389 gets(name); 1390 if (name[0] == '\0') 1391 return (1); 1392 if (name[0] == '?') { 1393 printf("\nList of GEOM managed disk devices:\n "); 1394 g_dev_print(); 1395 continue; 1396 } 1397 if (!vfs_mountroot_try(name)) 1398 return (0); 1399 } 1400} 1401 1402/* 1403 * Local helper function for vfs_mountroot_ask. 1404 */ 1405static void 1406gets(char *cp) 1407{ 1408 char *lp; 1409 int c; 1410 1411 lp = cp; 1412 for (;;) { 1413 printf("%c", c = cngetc() & 0177); 1414 switch (c) { 1415 case -1: 1416 case '\n': 1417 case '\r': 1418 *lp++ = '\0'; 1419 return; 1420 case '\b': 1421 case '\177': 1422 if (lp > cp) { 1423 printf(" \b"); 1424 lp--; 1425 } 1426 continue; 1427 case '#': 1428 lp--; 1429 if (lp < cp) 1430 lp = cp; 1431 continue; 1432 case '@': 1433 case 'u' & 037: 1434 lp = cp; 1435 printf("%c", '\n'); 1436 continue; 1437 default: 1438 *lp++ = c; 1439 } 1440 } 1441} 1442 1443/* 1444 * Convert a given name to the cdev pointer of the device, which is probably 1445 * but not by definition, a disk. Mount a DEVFS (on nothing), look the name 1446 * up, extract the cdev from the vnode and unmount it again. Unfortunately 1447 * we cannot use the vnode directly (because we unmount the DEVFS again) 1448 * so the filesystems still have to do the bdevvp() stunt. 1449 */ 1450struct cdev * 1451getdiskbyname(char *name) 1452{ 1453 char *cp = name; 1454 struct cdev *dev = NULL; 1455 struct thread *td = curthread; 1456 struct vfsconf *vfsp; 1457 struct mount *mp = NULL; 1458 struct vnode *vroot = NULL; 1459 struct nameidata nid; 1460 int error; 1461 1462 if (!bcmp(cp, "/dev/", 5)) 1463 cp += 5; 1464 1465 do { 1466 vfsp = vfs_byname("devfs"); 1467 if (vfsp == NULL) 1468 break; 1469 error = vfs_mount_alloc(NULLVP, vfsp, "/dev", td, &mp); 1470 if (error) 1471 break; 1472 mp->mnt_flag |= MNT_RDONLY; 1473 1474 error = VFS_MOUNT(mp, curthread); 1475 if (error) 1476 break; 1477 VFS_START(mp, 0, td); 1478 VFS_ROOT(mp, &vroot, td); 1479 VOP_UNLOCK(vroot, 0, td); 1480 1481 NDINIT(&nid, LOOKUP, NOCACHE|FOLLOW, 1482 UIO_SYSSPACE, cp, curthread); 1483 nid.ni_startdir = vroot; 1484 nid.ni_pathlen = strlen(cp); 1485 nid.ni_cnd.cn_cred = curthread->td_ucred; 1486 nid.ni_cnd.cn_nameptr = cp; 1487 1488 error = lookup(&nid); 1489 if (error) 1490 break; 1491 dev = vn_todev (nid.ni_vp); 1492 NDFREE(&nid, 0); 1493 } while (0); 1494 1495 if (vroot != NULL) 1496 VFS_UNMOUNT(mp, 0, td); 1497 if (mp != NULL) 1498 vfs_mount_destroy(mp, td); 1499 return (dev); 1500} 1501 1502/* Show the struct cdev *for a disk specified by name */ 1503#ifdef DDB 1504DB_SHOW_COMMAND(disk, db_getdiskbyname) 1505{ 1506 struct cdev *dev; 1507 1508 if (modif[0] == '\0') { 1509 db_error("usage: show disk/devicename"); 1510 return; 1511 } 1512 dev = getdiskbyname(modif); 1513 if (dev != NULL) 1514 db_printf("struct cdev *= %p\n", dev); 1515 else 1516 db_printf("No disk device matched.\n"); 1517} 1518#endif 1519 1520/* 1521 * Get a mount option by its name. 1522 * 1523 * Return 0 if the option was found, ENOENT otherwise. 1524 * If len is non-NULL it will be filled with the length 1525 * of the option. If buf is non-NULL, it will be filled 1526 * with the address of the option. 1527 */ 1528int 1529vfs_getopt(opts, name, buf, len) 1530 struct vfsoptlist *opts; 1531 const char *name; 1532 void **buf; 1533 int *len; 1534{ 1535 struct vfsopt *opt; 1536 1537 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1538 1539 TAILQ_FOREACH(opt, opts, link) { 1540 if (strcmp(name, opt->name) == 0) { 1541 if (len != NULL) 1542 *len = opt->len; 1543 if (buf != NULL) 1544 *buf = opt->value; 1545 return (0); 1546 } 1547 } 1548 return (ENOENT); 1549} 1550 1551/* 1552 * Find and copy a mount option. 1553 * 1554 * The size of the buffer has to be specified 1555 * in len, if it is not the same length as the 1556 * mount option, EINVAL is returned. 1557 * Returns ENOENT if the option is not found. 1558 */ 1559int 1560vfs_copyopt(opts, name, dest, len) 1561 struct vfsoptlist *opts; 1562 const char *name; 1563 void *dest; 1564 int len; 1565{ 1566 struct vfsopt *opt; 1567 1568 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1569 1570 TAILQ_FOREACH(opt, opts, link) { 1571 if (strcmp(name, opt->name) == 0) { 1572 if (len != opt->len) 1573 return (EINVAL); 1574 bcopy(opt->value, dest, opt->len); 1575 return (0); 1576 } 1577 } 1578 return (ENOENT); 1579} 1580 1581 1582/* 1583 * This is a helper function for filesystems to traverse their 1584 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1585 */ 1586 1587struct vnode * 1588__mnt_vnode_next(struct vnode **nvp, struct mount *mp) 1589{ 1590 struct vnode *vp; 1591 1592 mtx_assert(&mp->mnt_mtx, MA_OWNED); 1593 vp = *nvp; 1594 /* Check if we are done */ 1595 if (vp == NULL) 1596 return (NULL); 1597 /* If our next vnode is no longer ours, start over */ 1598 if (vp->v_mount != mp) 1599 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1600 /* Save pointer to next vnode in list */ 1601 if (vp != NULL) 1602 *nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1603 else 1604 *nvp = NULL; 1605 return (vp); 1606} 1607