vfs_mount.c revision 155902
1/*- 2 * Copyright (c) 1999-2004 Poul-Henning Kamp 3 * Copyright (c) 1999 Michael Smith 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/kern/vfs_mount.c 155902 2006-02-22 06:29:55Z jeff $"); 39 40#include <sys/param.h> 41#include <sys/conf.h> 42#include <sys/jail.h> 43#include <sys/kernel.h> 44#include <sys/libkern.h> 45#include <sys/mac.h> 46#include <sys/malloc.h> 47#include <sys/mount.h> 48#include <sys/mutex.h> 49#include <sys/namei.h> 50#include <sys/proc.h> 51#include <sys/filedesc.h> 52#include <sys/reboot.h> 53#include <sys/syscallsubr.h> 54#include <sys/sysproto.h> 55#include <sys/sx.h> 56#include <sys/sysctl.h> 57#include <sys/sysent.h> 58#include <sys/systm.h> 59#include <sys/vnode.h> 60 61#include <geom/geom.h> 62 63#include <machine/stdarg.h> 64 65#include "opt_rootdevname.h" 66#include "opt_ddb.h" 67#include "opt_mac.h" 68 69#ifdef DDB 70#include <ddb/ddb.h> 71#endif 72 73#define ROOTNAME "root_device" 74#define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 75 76static int vfs_domount(struct thread *td, const char *fstype, 77 char *fspath, int fsflags, void *fsdata); 78static struct mount *vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp, 79 const char *fspath, struct thread *td); 80static int vfs_mountroot_ask(void); 81static int vfs_mountroot_try(const char *mountfrom); 82static int vfs_donmount(struct thread *td, int fsflags, 83 struct uio *fsoptions); 84static void free_mntarg(struct mntarg *ma); 85static void vfs_mount_destroy(struct mount *, struct thread *); 86static int vfs_getopt_pos(struct vfsoptlist *opts, const char *name); 87 88static int usermount = 0; 89SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 90 "Unprivileged users may mount and unmount file systems"); 91 92MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 93MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 94 95/* List of mounted filesystems. */ 96struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 97 98/* For any iteration/modification of mountlist */ 99struct mtx mountlist_mtx; 100MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 101 102TAILQ_HEAD(vfsoptlist, vfsopt); 103struct vfsopt { 104 TAILQ_ENTRY(vfsopt) link; 105 char *name; 106 void *value; 107 int len; 108}; 109 110/* 111 * The vnode of the system's root (/ in the filesystem, without chroot 112 * active.) 113 */ 114struct vnode *rootvnode; 115 116/* 117 * The root filesystem is detailed in the kernel environment variable 118 * vfs.root.mountfrom, which is expected to be in the general format 119 * 120 * <vfsname>:[<path>] 121 * vfsname := the name of a VFS known to the kernel and capable 122 * of being mounted as root 123 * path := disk device name or other data used by the filesystem 124 * to locate its physical store 125 */ 126 127/* 128 * Global opts, taken by all filesystems 129 */ 130static const char *global_opts[] = { 131 "errmsg", 132 "fstype", 133 "fspath", 134 "rdonly", 135 "ro", 136 "rw", 137 "suid", 138 "exec", 139 NULL 140}; 141 142/* 143 * The root specifiers we will try if RB_CDROM is specified. 144 */ 145static char *cdrom_rootdevnames[] = { 146 "cd9660:cd0", 147 "cd9660:acd0", 148 NULL 149}; 150 151/* legacy find-root code */ 152char *rootdevnames[2] = {NULL, NULL}; 153#ifndef ROOTDEVNAME 154# define ROOTDEVNAME NULL 155#endif 156static const char *ctrootdevname = ROOTDEVNAME; 157 158/* 159 * --------------------------------------------------------------------- 160 * Functions for building and sanitizing the mount options 161 */ 162 163/* Remove one mount option. */ 164static void 165vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 166{ 167 168 TAILQ_REMOVE(opts, opt, link); 169 free(opt->name, M_MOUNT); 170 if (opt->value != NULL) 171 free(opt->value, M_MOUNT); 172#ifdef INVARIANTS 173 else if (opt->len != 0) 174 panic("%s: mount option with NULL value but length != 0", 175 __func__); 176#endif 177 free(opt, M_MOUNT); 178} 179 180/* Release all resources related to the mount options. */ 181static void 182vfs_freeopts(struct vfsoptlist *opts) 183{ 184 struct vfsopt *opt; 185 186 while (!TAILQ_EMPTY(opts)) { 187 opt = TAILQ_FIRST(opts); 188 vfs_freeopt(opts, opt); 189 } 190 free(opts, M_MOUNT); 191} 192 193/* 194 * Check if options are equal (with or without the "no" prefix). 195 */ 196static int 197vfs_equalopts(const char *opt1, const char *opt2) 198{ 199 200 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 201 if (strcmp(opt1, opt2) == 0) 202 return (1); 203 /* "noopt" vs. "opt" */ 204 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 205 return (1); 206 /* "opt" vs. "noopt" */ 207 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 208 return (1); 209 return (0); 210} 211 212/* 213 * If a mount option is specified several times, 214 * (with or without the "no" prefix) only keep 215 * the last occurence of it. 216 */ 217static void 218vfs_sanitizeopts(struct vfsoptlist *opts) 219{ 220 struct vfsopt *opt, *opt2, *tmp; 221 222 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 223 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 224 while (opt2 != NULL) { 225 if (vfs_equalopts(opt->name, opt2->name)) { 226 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 227 vfs_freeopt(opts, opt2); 228 opt2 = tmp; 229 } else { 230 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 231 } 232 } 233 } 234} 235 236/* 237 * Build a linked list of mount options from a struct uio. 238 */ 239static int 240vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 241{ 242 struct vfsoptlist *opts; 243 struct vfsopt *opt; 244 size_t memused; 245 unsigned int i, iovcnt; 246 int error, namelen, optlen; 247 248 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 249 TAILQ_INIT(opts); 250 memused = 0; 251 iovcnt = auio->uio_iovcnt; 252 for (i = 0; i < iovcnt; i += 2) { 253 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 254 namelen = auio->uio_iov[i].iov_len; 255 optlen = auio->uio_iov[i + 1].iov_len; 256 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 257 opt->value = NULL; 258 opt->len = 0; 259 260 /* 261 * Do this early, so jumps to "bad" will free the current 262 * option. 263 */ 264 TAILQ_INSERT_TAIL(opts, opt, link); 265 memused += sizeof(struct vfsopt) + optlen + namelen; 266 267 /* 268 * Avoid consuming too much memory, and attempts to overflow 269 * memused. 270 */ 271 if (memused > VFS_MOUNTARG_SIZE_MAX || 272 optlen > VFS_MOUNTARG_SIZE_MAX || 273 namelen > VFS_MOUNTARG_SIZE_MAX) { 274 error = EINVAL; 275 goto bad; 276 } 277 278 if (auio->uio_segflg == UIO_SYSSPACE) { 279 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 280 } else { 281 error = copyin(auio->uio_iov[i].iov_base, opt->name, 282 namelen); 283 if (error) 284 goto bad; 285 } 286 /* Ensure names are null-terminated strings. */ 287 if (opt->name[namelen - 1] != '\0') { 288 error = EINVAL; 289 goto bad; 290 } 291 if (optlen != 0) { 292 opt->len = optlen; 293 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 294 if (auio->uio_segflg == UIO_SYSSPACE) { 295 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 296 optlen); 297 } else { 298 error = copyin(auio->uio_iov[i + 1].iov_base, 299 opt->value, optlen); 300 if (error) 301 goto bad; 302 } 303 } 304 } 305 vfs_sanitizeopts(opts); 306 *options = opts; 307 return (0); 308bad: 309 vfs_freeopts(opts); 310 return (error); 311} 312 313/* 314 * Merge the old mount options with the new ones passed 315 * in the MNT_UPDATE case. 316 */ 317static void 318vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 319{ 320 struct vfsopt *opt, *opt2, *new; 321 322 TAILQ_FOREACH(opt, opts, link) { 323 /* 324 * Check that this option hasn't been redefined 325 * nor cancelled with a "no" mount option. 326 */ 327 opt2 = TAILQ_FIRST(toopts); 328 while (opt2 != NULL) { 329 if (strcmp(opt2->name, opt->name) == 0) 330 goto next; 331 if (strncmp(opt2->name, "no", 2) == 0 && 332 strcmp(opt2->name + 2, opt->name) == 0) { 333 vfs_freeopt(toopts, opt2); 334 goto next; 335 } 336 opt2 = TAILQ_NEXT(opt2, link); 337 } 338 /* We want this option, duplicate it. */ 339 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 340 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 341 strcpy(new->name, opt->name); 342 if (opt->len != 0) { 343 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 344 bcopy(opt->value, new->value, opt->len); 345 } else { 346 new->value = NULL; 347 } 348 new->len = opt->len; 349 TAILQ_INSERT_TAIL(toopts, new, link); 350next: 351 continue; 352 } 353} 354 355/* 356 * --------------------------------------------------------------------- 357 * Mount a filesystem 358 */ 359int 360nmount(td, uap) 361 struct thread *td; 362 struct nmount_args /* { 363 struct iovec *iovp; 364 unsigned int iovcnt; 365 int flags; 366 } */ *uap; 367{ 368 struct uio *auio; 369 struct iovec *iov; 370 unsigned int i; 371 int error; 372 u_int iovcnt; 373 374 /* Kick out MNT_ROOTFS early as it is legal internally */ 375 if (uap->flags & MNT_ROOTFS) 376 return (EINVAL); 377 378 iovcnt = uap->iovcnt; 379 /* 380 * Check that we have an even number of iovec's 381 * and that we have at least two options. 382 */ 383 if ((iovcnt & 1) || (iovcnt < 4)) 384 return (EINVAL); 385 386 error = copyinuio(uap->iovp, iovcnt, &auio); 387 if (error) 388 return (error); 389 iov = auio->uio_iov; 390 for (i = 0; i < iovcnt; i++) { 391 if (iov->iov_len > MMAXOPTIONLEN) { 392 free(auio, M_IOV); 393 return (EINVAL); 394 } 395 iov++; 396 } 397 error = vfs_donmount(td, uap->flags, auio); 398 399 free(auio, M_IOV); 400 return (error); 401} 402 403/* 404 * --------------------------------------------------------------------- 405 * Various utility functions 406 */ 407 408void 409vfs_ref(struct mount *mp) 410{ 411 412 MNT_ILOCK(mp); 413 MNT_REF(mp); 414 MNT_IUNLOCK(mp); 415} 416 417void 418vfs_rel(struct mount *mp) 419{ 420 421 MNT_ILOCK(mp); 422 MNT_REL(mp); 423 MNT_IUNLOCK(mp); 424} 425 426/* 427 * Allocate and initialize the mount point struct. 428 */ 429static struct mount * 430vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 431 const char *fspath, struct thread *td) 432{ 433 struct mount *mp; 434 435 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 436 TAILQ_INIT(&mp->mnt_nvnodelist); 437 mp->mnt_nvnodelistsize = 0; 438 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 439 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 440 (void) vfs_busy(mp, LK_NOWAIT, 0, td); 441 mp->mnt_ref = 0; 442 mp->mnt_op = vfsp->vfc_vfsops; 443 mp->mnt_vfc = vfsp; 444 vfsp->vfc_refcount++; /* XXX Unlocked */ 445 mp->mnt_stat.f_type = vfsp->vfc_typenum; 446 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 447 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 448 mp->mnt_vnodecovered = vp; 449 mp->mnt_cred = crdup(td->td_ucred); 450 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 451 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 452 mp->mnt_iosize_max = DFLTPHYS; 453#ifdef MAC 454 mac_init_mount(mp); 455 mac_create_mount(td->td_ucred, mp); 456#endif 457 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 458 return (mp); 459} 460 461/* 462 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 463 */ 464static void 465vfs_mount_destroy(struct mount *mp, struct thread *td) 466{ 467 int i; 468 469 vfs_unbusy(mp, td); 470 MNT_ILOCK(mp); 471 for (i = 0; mp->mnt_ref && i < 3; i++) 472 msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz); 473 /* 474 * This will always cause a 3 second delay in rebooting due to 475 * refs on the root mountpoint that never go away. Most of these 476 * are held by init which never exits. 477 */ 478 if (i == 3 && (!rebooting || bootverbose)) 479 printf("Mount point %s had %d dangling refs\n", 480 mp->mnt_stat.f_mntonname, mp->mnt_ref); 481 if (mp->mnt_holdcnt != 0) { 482 printf("Waiting for mount point to be unheld\n"); 483 while (mp->mnt_holdcnt != 0) { 484 mp->mnt_holdcntwaiters++; 485 msleep(&mp->mnt_holdcnt, MNT_MTX(mp), 486 PZERO, "mntdestroy", 0); 487 mp->mnt_holdcntwaiters--; 488 } 489 printf("mount point unheld\n"); 490 } 491 if (mp->mnt_writeopcount > 0) { 492 printf("Waiting for mount point write ops\n"); 493 while (mp->mnt_writeopcount > 0) { 494 mp->mnt_kern_flag |= MNTK_SUSPEND; 495 msleep(&mp->mnt_writeopcount, 496 MNT_MTX(mp), 497 PZERO, "mntdestroy2", 0); 498 } 499 printf("mount point write ops completed\n"); 500 } 501 MNT_IUNLOCK(mp); 502 mp->mnt_vfc->vfc_refcount--; 503 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 504 panic("unmount: dangling vnode"); 505 lockdestroy(&mp->mnt_lock); 506 MNT_ILOCK(mp); 507 if (mp->mnt_kern_flag & MNTK_MWAIT) 508 wakeup(mp); 509 if (mp->mnt_writeopcount != 0) 510 panic("vfs_mount_destroy: nonzero writeopcount"); 511 if (mp->mnt_nvnodelistsize != 0) 512 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 513 mp->mnt_writeopcount = -1000; 514 mp->mnt_nvnodelistsize = -1000; 515 MNT_IUNLOCK(mp); 516 mtx_destroy(&mp->mnt_mtx); 517#ifdef MAC 518 mac_destroy_mount(mp); 519#endif 520 if (mp->mnt_opt != NULL) 521 vfs_freeopts(mp->mnt_opt); 522 crfree(mp->mnt_cred); 523 free(mp, M_MOUNT); 524} 525 526static int 527vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 528{ 529 struct vfsoptlist *optlist; 530 char *fstype, *fspath, *errmsg; 531 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 532 533 errmsg_len = 0; 534 errmsg_pos = -1; 535 536 error = vfs_buildopts(fsoptions, &optlist); 537 if (error) 538 return (error); 539 540 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 541 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 542 else 543 errmsg_len = 0; 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 if (errmsg != NULL) 555 strncpy(errmsg, "Invalid fstype", errmsg_len); 556 goto bail; 557 } 558 fspathlen = 0; 559 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 560 if (error || fspath[fspathlen - 1] != '\0') { 561 error = EINVAL; 562 if (errmsg != NULL) 563 strncpy(errmsg, "Invalid fspath", errmsg_len); 564 goto bail; 565 } 566 567 /* 568 * We need to see if we have the "update" option 569 * before we call vfs_domount(), since vfs_domount() has special 570 * logic based on MNT_UPDATE. This is very important 571 * when we want to update the root filesystem. 572 */ 573 if (vfs_getopt(optlist, "update", NULL, NULL) == 0) 574 fsflags |= MNT_UPDATE; 575 576 if (vfs_getopt(optlist, "async", NULL, NULL) == 0) 577 fsflags |= MNT_ASYNC; 578 579 if (vfs_getopt(optlist, "force", NULL, NULL) == 0) 580 fsflags |= MNT_FORCE; 581 582 if (vfs_getopt(optlist, "multilabel", NULL, NULL) == 0) 583 fsflags |= MNT_MULTILABEL; 584 585 if (vfs_getopt(optlist, "noasync", NULL, NULL) == 0) 586 fsflags &= ~MNT_ASYNC; 587 588 if (vfs_getopt(optlist, "noatime", NULL, NULL) == 0) 589 fsflags |= MNT_NOATIME; 590 591 if (vfs_getopt(optlist, "noclusterr", NULL, NULL) == 0) 592 fsflags |= MNT_NOCLUSTERR; 593 594 if (vfs_getopt(optlist, "noclusterw", NULL, NULL) == 0) 595 fsflags |= MNT_NOCLUSTERW; 596 597 if (vfs_getopt(optlist, "noexec", NULL, NULL) == 0) 598 fsflags |= MNT_NOEXEC; 599 600 if (vfs_getopt(optlist, "nosuid", NULL, NULL) == 0) 601 fsflags |= MNT_NOSUID; 602 603 if (vfs_getopt(optlist, "nosymfollow", NULL, NULL) == 0) 604 fsflags |= MNT_NOSYMFOLLOW; 605 606 if (vfs_getopt(optlist, "noro", NULL, NULL) == 0) 607 fsflags &= ~MNT_RDONLY; 608 609 if (vfs_getopt(optlist, "ro", NULL, NULL) == 0) 610 fsflags |= MNT_RDONLY; 611 612 if (vfs_getopt(optlist, "rdonly", NULL, NULL) == 0) 613 fsflags |= MNT_RDONLY; 614 615 if (vfs_getopt(optlist, "rw", NULL, NULL) == 0) 616 fsflags &= ~MNT_RDONLY; 617 618 if (vfs_getopt(optlist, "snapshot", NULL, NULL) == 0) 619 fsflags |= MNT_SNAPSHOT; 620 621 if (vfs_getopt(optlist, "suiddir", NULL, NULL) == 0) 622 fsflags |= MNT_SUIDDIR; 623 624 if (vfs_getopt(optlist, "sync", NULL, NULL) == 0) 625 fsflags |= MNT_SYNCHRONOUS; 626 627 if (vfs_getopt(optlist, "union", NULL, NULL) == 0) 628 fsflags |= MNT_UNION; 629 630 /* 631 * Be ultra-paranoid about making sure the type and fspath 632 * variables will fit in our mp buffers, including the 633 * terminating NUL. 634 */ 635 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 636 error = ENAMETOOLONG; 637 goto bail; 638 } 639 640 mtx_lock(&Giant); 641 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 642 mtx_unlock(&Giant); 643bail: 644 /* copyout the errmsg */ 645 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 646 && errmsg_len > 0 && errmsg != NULL) { 647 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 648 strncpy(fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 649 errmsg, 650 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 651 } else { 652 copystr(errmsg, 653 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 654 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len, 655 NULL); 656 } 657 } 658 659 if (error != 0) 660 vfs_freeopts(optlist); 661 return (error); 662} 663 664/* 665 * --------------------------------------------------------------------- 666 * Old mount API. 667 */ 668#ifndef _SYS_SYSPROTO_H_ 669struct mount_args { 670 char *type; 671 char *path; 672 int flags; 673 caddr_t data; 674}; 675#endif 676/* ARGSUSED */ 677int 678mount(td, uap) 679 struct thread *td; 680 struct mount_args /* { 681 char *type; 682 char *path; 683 int flags; 684 caddr_t data; 685 } */ *uap; 686{ 687 char *fstype; 688 struct vfsconf *vfsp = NULL; 689 struct mntarg *ma = NULL; 690 int error; 691 692 /* Kick out MNT_ROOTFS early as it is legal internally */ 693 uap->flags &= ~MNT_ROOTFS; 694 695 if (uap->data == NULL) 696 return (EINVAL); 697 698 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 699 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 700 if (!error) { 701 mtx_lock(&Giant); /* XXX ? */ 702 vfsp = vfs_byname_kld(fstype, td, &error); 703 mtx_unlock(&Giant); 704 } 705 free(fstype, M_TEMP); 706 if (error) 707 return (error); 708 if (vfsp == NULL) 709 return (ENOENT); 710 if (vfsp->vfc_vfsops->vfs_cmount == NULL) 711 return (EOPNOTSUPP); 712 713 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 714 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 715 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 716 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 717 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 718 719 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 720 return (error); 721} 722 723 724/* 725 * vfs_domount(): actually attempt a filesystem mount. 726 */ 727static int 728vfs_domount( 729 struct thread *td, /* Flags common to all filesystems. */ 730 const char *fstype, /* Filesystem type. */ 731 char *fspath, /* Mount path. */ 732 int fsflags, /* Flags common to all filesystems. */ 733 void *fsdata /* Options local to the filesystem. */ 734 ) 735{ 736 struct vnode *vp; 737 struct mount *mp; 738 struct vfsconf *vfsp; 739 int error, flag = 0, kern_flag = 0; 740 struct vattr va; 741 struct nameidata nd; 742 743 mtx_assert(&Giant, MA_OWNED); 744 /* 745 * Be ultra-paranoid about making sure the type and fspath 746 * variables will fit in our mp buffers, including the 747 * terminating NUL. 748 */ 749 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 750 return (ENAMETOOLONG); 751 752 if (jailed(td->td_ucred)) 753 return (EPERM); 754 if (usermount == 0) { 755 if ((error = suser(td)) != 0) 756 return (error); 757 } 758 759 /* 760 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 761 */ 762 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 763 if ((error = suser(td)) != 0) 764 return (error); 765 } 766 /* 767 * Silently enforce MNT_NOSUID and MNT_USER for 768 * unprivileged users. 769 */ 770 if (suser(td) != 0) 771 fsflags |= MNT_NOSUID | MNT_USER; 772 773 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 774 vfsp = NULL; 775 if ((fsflags & MNT_UPDATE) == 0) { 776 /* Don't try to load KLDs if we're mounting the root. */ 777 if (fsflags & MNT_ROOTFS) 778 vfsp = vfs_byname(fstype); 779 else 780 vfsp = vfs_byname_kld(fstype, td, &error); 781 if (vfsp == NULL) 782 return (ENODEV); 783 } 784 /* 785 * Get vnode to be covered 786 */ 787 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 788 if ((error = namei(&nd)) != 0) 789 return (error); 790 NDFREE(&nd, NDF_ONLY_PNBUF); 791 vp = nd.ni_vp; 792 if (fsflags & MNT_UPDATE) { 793 if ((vp->v_vflag & VV_ROOT) == 0) { 794 vput(vp); 795 return (EINVAL); 796 } 797 mp = vp->v_mount; 798 flag = mp->mnt_flag; 799 kern_flag = mp->mnt_kern_flag; 800 /* 801 * We only allow the filesystem to be reloaded if it 802 * is currently mounted read-only. 803 */ 804 if ((fsflags & MNT_RELOAD) && 805 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 806 vput(vp); 807 return (EOPNOTSUPP); /* Needs translation */ 808 } 809 /* 810 * Only privileged root, or (if MNT_USER is set) the user that 811 * did the original mount is permitted to update it. 812 */ 813 error = vfs_suser(mp, td); 814 if (error) { 815 vput(vp); 816 return (error); 817 } 818 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 819 vput(vp); 820 return (EBUSY); 821 } 822 VI_LOCK(vp); 823 if ((vp->v_iflag & VI_MOUNT) != 0 || 824 vp->v_mountedhere != NULL) { 825 VI_UNLOCK(vp); 826 vfs_unbusy(mp, td); 827 vput(vp); 828 return (EBUSY); 829 } 830 vp->v_iflag |= VI_MOUNT; 831 VI_UNLOCK(vp); 832 mp->mnt_flag |= fsflags & 833 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 834 VOP_UNLOCK(vp, 0, td); 835 mp->mnt_optnew = fsdata; 836 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 837 } else { 838 /* 839 * If the user is not root, ensure that they own the directory 840 * onto which we are attempting to mount. 841 */ 842 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 843 if (error) { 844 vput(vp); 845 return (error); 846 } 847 if (va.va_uid != td->td_ucred->cr_uid) { 848 if ((error = suser(td)) != 0) { 849 vput(vp); 850 return (error); 851 } 852 } 853 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 854 if (error != 0) { 855 vput(vp); 856 return (error); 857 } 858 if (vp->v_type != VDIR) { 859 vput(vp); 860 return (ENOTDIR); 861 } 862 VI_LOCK(vp); 863 if ((vp->v_iflag & VI_MOUNT) != 0 || 864 vp->v_mountedhere != NULL) { 865 VI_UNLOCK(vp); 866 vput(vp); 867 return (EBUSY); 868 } 869 vp->v_iflag |= VI_MOUNT; 870 VI_UNLOCK(vp); 871 872 /* 873 * Allocate and initialize the filesystem. 874 */ 875 mp = vfs_mount_alloc(vp, vfsp, fspath, td); 876 VOP_UNLOCK(vp, 0, td); 877 878 /* XXXMAC: pass to vfs_mount_alloc? */ 879 mp->mnt_optnew = fsdata; 880 } 881 882 /* 883 * Set the mount level flags. 884 */ 885 if (fsflags & MNT_RDONLY) 886 mp->mnt_flag |= MNT_RDONLY; 887 mp->mnt_flag &=~ MNT_UPDATEMASK; 888 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS); 889 /* 890 * Mount the filesystem. 891 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 892 * get. No freeing of cn_pnbuf. 893 */ 894 error = VFS_MOUNT(mp, td); 895 if (!error) { 896 if (mp->mnt_opt != NULL) 897 vfs_freeopts(mp->mnt_opt); 898 mp->mnt_opt = mp->mnt_optnew; 899 (void)VFS_STATFS(mp, &mp->mnt_stat, td); 900 } 901 /* 902 * Prevent external consumers of mount options from reading 903 * mnt_optnew. 904 */ 905 mp->mnt_optnew = NULL; 906 if (mp->mnt_flag & MNT_UPDATE) { 907 mp->mnt_flag &= 908 ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 909 if (error) { 910 mp->mnt_flag = flag; 911 mp->mnt_kern_flag = kern_flag; 912 } 913 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 914 if (mp->mnt_syncer == NULL) 915 error = vfs_allocate_syncvnode(mp); 916 } else { 917 if (mp->mnt_syncer != NULL) 918 vrele(mp->mnt_syncer); 919 mp->mnt_syncer = NULL; 920 } 921 vfs_unbusy(mp, td); 922 VI_LOCK(vp); 923 vp->v_iflag &= ~VI_MOUNT; 924 VI_UNLOCK(vp); 925 vrele(vp); 926 return (error); 927 } 928 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 929 /* 930 * Put the new filesystem on the mount list after root. 931 */ 932 cache_purge(vp); 933 if (!error) { 934 struct vnode *newdp; 935 936 VI_LOCK(vp); 937 vp->v_iflag &= ~VI_MOUNT; 938 VI_UNLOCK(vp); 939 vp->v_mountedhere = mp; 940 mtx_lock(&mountlist_mtx); 941 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 942 mtx_unlock(&mountlist_mtx); 943 vfs_event_signal(NULL, VQ_MOUNT, 0); 944 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 945 panic("mount: lost mount"); 946 mountcheckdirs(vp, newdp); 947 vput(newdp); 948 VOP_UNLOCK(vp, 0, td); 949 if ((mp->mnt_flag & MNT_RDONLY) == 0) 950 error = vfs_allocate_syncvnode(mp); 951 vfs_unbusy(mp, td); 952 if (error) 953 vrele(vp); 954 } else { 955 VI_LOCK(vp); 956 vp->v_iflag &= ~VI_MOUNT; 957 VI_UNLOCK(vp); 958 vfs_mount_destroy(mp, td); 959 vput(vp); 960 } 961 return (error); 962} 963 964/* 965 * --------------------------------------------------------------------- 966 * Unmount a filesystem. 967 * 968 * Note: unmount takes a path to the vnode mounted on as argument, 969 * not special file (as before). 970 */ 971#ifndef _SYS_SYSPROTO_H_ 972struct unmount_args { 973 char *path; 974 int flags; 975}; 976#endif 977/* ARGSUSED */ 978int 979unmount(td, uap) 980 struct thread *td; 981 register struct unmount_args /* { 982 char *path; 983 int flags; 984 } */ *uap; 985{ 986 struct mount *mp; 987 char *pathbuf; 988 int error, id0, id1; 989 990 if (jailed(td->td_ucred)) 991 return (EPERM); 992 if (usermount == 0) { 993 if ((error = suser(td)) != 0) 994 return (error); 995 } 996 997 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 998 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 999 if (error) { 1000 free(pathbuf, M_TEMP); 1001 return (error); 1002 } 1003 if (uap->flags & MNT_BYFSID) { 1004 /* Decode the filesystem ID. */ 1005 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1006 free(pathbuf, M_TEMP); 1007 return (EINVAL); 1008 } 1009 1010 mtx_lock(&mountlist_mtx); 1011 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1012 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1013 mp->mnt_stat.f_fsid.val[1] == id1) 1014 break; 1015 } 1016 mtx_unlock(&mountlist_mtx); 1017 } else { 1018 mtx_lock(&mountlist_mtx); 1019 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1020 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1021 break; 1022 } 1023 mtx_unlock(&mountlist_mtx); 1024 } 1025 free(pathbuf, M_TEMP); 1026 if (mp == NULL) { 1027 /* 1028 * Previously we returned ENOENT for a nonexistent path and 1029 * EINVAL for a non-mountpoint. We cannot tell these apart 1030 * now, so in the !MNT_BYFSID case return the more likely 1031 * EINVAL for compatibility. 1032 */ 1033 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1034 } 1035 1036 /* 1037 * Only privileged root, or (if MNT_USER is set) the user that did the 1038 * original mount is permitted to unmount this filesystem. 1039 */ 1040 error = vfs_suser(mp, td); 1041 if (error) 1042 return (error); 1043 1044 /* 1045 * Don't allow unmounting the root filesystem. 1046 */ 1047 if (mp->mnt_flag & MNT_ROOTFS) 1048 return (EINVAL); 1049 mtx_lock(&Giant); 1050 error = dounmount(mp, uap->flags, td); 1051 mtx_unlock(&Giant); 1052 return (error); 1053} 1054 1055/* 1056 * Do the actual filesystem unmount. 1057 */ 1058int 1059dounmount(mp, flags, td) 1060 struct mount *mp; 1061 int flags; 1062 struct thread *td; 1063{ 1064 struct vnode *coveredvp, *fsrootvp; 1065 int error; 1066 int async_flag; 1067 1068 mtx_assert(&Giant, MA_OWNED); 1069 1070 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 1071 vn_lock(coveredvp, LK_EXCLUSIVE | LK_RETRY, td); 1072 MNT_ILOCK(mp); 1073 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1074 MNT_IUNLOCK(mp); 1075 if (coveredvp) 1076 VOP_UNLOCK(coveredvp, 0, td); 1077 return (EBUSY); 1078 } 1079 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1080 /* Allow filesystems to detect that a forced unmount is in progress. */ 1081 if (flags & MNT_FORCE) 1082 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1083 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1084 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td); 1085 if (error) { 1086 MNT_ILOCK(mp); 1087 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1088 if (mp->mnt_kern_flag & MNTK_MWAIT) 1089 wakeup(mp); 1090 MNT_IUNLOCK(mp); 1091 if (coveredvp) 1092 VOP_UNLOCK(coveredvp, 0, td); 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) && 1112 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1113 if (mp->mnt_vnodecovered != NULL) 1114 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 1115 if (fsrootvp == rootvnode) { 1116 vrele(rootvnode); 1117 rootvnode = NULL; 1118 } 1119 vput(fsrootvp); 1120 } 1121 if (((mp->mnt_flag & MNT_RDONLY) || 1122 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 1123 (flags & MNT_FORCE)) { 1124 error = VFS_UNMOUNT(mp, flags, td); 1125 } 1126 vn_finished_write(mp); 1127 if (error) { 1128 /* Undo cdir/rdir and rootvnode changes made above. */ 1129 if ((flags & MNT_FORCE) && 1130 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1131 if (mp->mnt_vnodecovered != NULL) 1132 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 1133 if (rootvnode == NULL) { 1134 rootvnode = fsrootvp; 1135 vref(rootvnode); 1136 } 1137 vput(fsrootvp); 1138 } 1139 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1140 (void) vfs_allocate_syncvnode(mp); 1141 MNT_ILOCK(mp); 1142 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1143 mp->mnt_flag |= async_flag; 1144 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1145 if (mp->mnt_kern_flag & MNTK_MWAIT) 1146 wakeup(mp); 1147 MNT_IUNLOCK(mp); 1148 if (coveredvp) 1149 VOP_UNLOCK(coveredvp, 0, td); 1150 return (error); 1151 } 1152 mtx_lock(&mountlist_mtx); 1153 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1154 mtx_unlock(&mountlist_mtx); 1155 if (coveredvp != NULL) { 1156 coveredvp->v_mountedhere = NULL; 1157 vput(coveredvp); 1158 } 1159 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1160 vfs_mount_destroy(mp, td); 1161 return (0); 1162} 1163 1164/* 1165 * --------------------------------------------------------------------- 1166 * Mounting of root filesystem 1167 * 1168 */ 1169 1170struct root_hold_token { 1171 const char *who; 1172 LIST_ENTRY(root_hold_token) list; 1173}; 1174 1175static LIST_HEAD(, root_hold_token) root_holds = 1176 LIST_HEAD_INITIALIZER(&root_holds); 1177 1178struct root_hold_token * 1179root_mount_hold(const char *identifier) 1180{ 1181 struct root_hold_token *h; 1182 1183 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1184 h->who = identifier; 1185 mtx_lock(&mountlist_mtx); 1186 LIST_INSERT_HEAD(&root_holds, h, list); 1187 mtx_unlock(&mountlist_mtx); 1188 return (h); 1189} 1190 1191void 1192root_mount_rel(struct root_hold_token *h) 1193{ 1194 1195 mtx_lock(&mountlist_mtx); 1196 LIST_REMOVE(h, list); 1197 wakeup(&root_holds); 1198 mtx_unlock(&mountlist_mtx); 1199 free(h, M_DEVBUF); 1200} 1201 1202static void 1203root_mount_wait(void) 1204{ 1205 struct root_hold_token *h; 1206 1207 for (;;) { 1208 DROP_GIANT(); 1209 g_waitidle(); 1210 PICKUP_GIANT(); 1211 mtx_lock(&mountlist_mtx); 1212 if (LIST_EMPTY(&root_holds)) { 1213 mtx_unlock(&mountlist_mtx); 1214 break; 1215 } 1216 printf("Root mount waiting for:"); 1217 LIST_FOREACH(h, &root_holds, list) 1218 printf(" %s", h->who); 1219 printf("\n"); 1220 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1221 hz); 1222 } 1223} 1224 1225static void 1226set_rootvnode(struct thread *td) 1227{ 1228 struct proc *p; 1229 1230 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1231 panic("Cannot find root vnode"); 1232 1233 p = td->td_proc; 1234 FILEDESC_LOCK(p->p_fd); 1235 1236 if (p->p_fd->fd_cdir != NULL) 1237 vrele(p->p_fd->fd_cdir); 1238 p->p_fd->fd_cdir = rootvnode; 1239 VREF(rootvnode); 1240 1241 if (p->p_fd->fd_rdir != NULL) 1242 vrele(p->p_fd->fd_rdir); 1243 p->p_fd->fd_rdir = rootvnode; 1244 VREF(rootvnode); 1245 1246 FILEDESC_UNLOCK(p->p_fd); 1247 1248 VOP_UNLOCK(rootvnode, 0, td); 1249} 1250 1251/* 1252 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1253 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1254 */ 1255 1256static void 1257devfs_first(void) 1258{ 1259 struct thread *td = curthread; 1260 struct vfsoptlist *opts; 1261 struct vfsconf *vfsp; 1262 struct mount *mp = NULL; 1263 int error; 1264 1265 vfsp = vfs_byname("devfs"); 1266 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1267 if (vfsp == NULL) 1268 return; 1269 1270 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td); 1271 1272 error = VFS_MOUNT(mp, td); 1273 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1274 if (error) 1275 return; 1276 1277 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 1278 TAILQ_INIT(opts); 1279 mp->mnt_opt = opts; 1280 1281 mtx_lock(&mountlist_mtx); 1282 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1283 mtx_unlock(&mountlist_mtx); 1284 1285 set_rootvnode(td); 1286 1287 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1288 if (error) 1289 printf("kern_symlink /dev -> / returns %d\n", error); 1290} 1291 1292/* 1293 * Surgically move our devfs to be mounted on /dev. 1294 */ 1295 1296static void 1297devfs_fixup(struct thread *td) 1298{ 1299 struct nameidata nd; 1300 int error; 1301 struct vnode *vp, *dvp; 1302 struct mount *mp; 1303 1304 /* Remove our devfs mount from the mountlist and purge the cache */ 1305 mtx_lock(&mountlist_mtx); 1306 mp = TAILQ_FIRST(&mountlist); 1307 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1308 mtx_unlock(&mountlist_mtx); 1309 cache_purgevfs(mp); 1310 1311 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1312 VI_LOCK(dvp); 1313 dvp->v_iflag &= ~VI_MOUNT; 1314 dvp->v_mountedhere = NULL; 1315 VI_UNLOCK(dvp); 1316 1317 /* Set up the real rootvnode, and purge the cache */ 1318 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1319 set_rootvnode(td); 1320 cache_purgevfs(rootvnode->v_mount); 1321 1322 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1323 error = namei(&nd); 1324 if (error) { 1325 printf("Lookup of /dev for devfs, error: %d\n", error); 1326 return; 1327 } 1328 NDFREE(&nd, NDF_ONLY_PNBUF); 1329 vp = nd.ni_vp; 1330 if (vp->v_type != VDIR) { 1331 vput(vp); 1332 } 1333 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1334 if (error) { 1335 vput(vp); 1336 } 1337 cache_purge(vp); 1338 mp->mnt_vnodecovered = vp; 1339 vp->v_mountedhere = mp; 1340 mtx_lock(&mountlist_mtx); 1341 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1342 mtx_unlock(&mountlist_mtx); 1343 VOP_UNLOCK(vp, 0, td); 1344 vput(dvp); 1345 vfs_unbusy(mp, td); 1346 1347 /* Unlink the no longer needed /dev/dev -> / symlink */ 1348 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1349} 1350 1351/* 1352 * Report errors during filesystem mounting. 1353 */ 1354void 1355vfs_mount_error(struct mount *mp, const char *fmt, ...) 1356{ 1357 struct vfsoptlist *moptlist = mp->mnt_optnew; 1358 va_list ap; 1359 int error, len; 1360 char *errmsg; 1361 1362 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1363 if (error || errmsg == NULL || len <= 0) 1364 return; 1365 1366 va_start(ap, fmt); 1367 vsnprintf(errmsg, (size_t)len, fmt, ap); 1368 va_end(ap); 1369} 1370 1371/* 1372 * Find and mount the root filesystem 1373 */ 1374void 1375vfs_mountroot(void) 1376{ 1377 char *cp; 1378 int error, i, asked = 0; 1379 1380 root_mount_wait(); 1381 1382 devfs_first(); 1383 1384 /* 1385 * We are booted with instructions to prompt for the root filesystem. 1386 */ 1387 if (boothowto & RB_ASKNAME) { 1388 if (!vfs_mountroot_ask()) 1389 return; 1390 asked = 1; 1391 } 1392 1393 /* 1394 * The root filesystem information is compiled in, and we are 1395 * booted with instructions to use it. 1396 */ 1397 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1398 if (!vfs_mountroot_try(ctrootdevname)) 1399 return; 1400 ctrootdevname = NULL; 1401 } 1402 1403 /* 1404 * We've been given the generic "use CDROM as root" flag. This is 1405 * necessary because one media may be used in many different 1406 * devices, so we need to search for them. 1407 */ 1408 if (boothowto & RB_CDROM) { 1409 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1410 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1411 return; 1412 } 1413 } 1414 1415 /* 1416 * Try to use the value read by the loader from /etc/fstab, or 1417 * supplied via some other means. This is the preferred 1418 * mechanism. 1419 */ 1420 cp = getenv("vfs.root.mountfrom"); 1421 if (cp != NULL) { 1422 error = vfs_mountroot_try(cp); 1423 freeenv(cp); 1424 if (!error) 1425 return; 1426 } 1427 1428 /* 1429 * Try values that may have been computed by code during boot 1430 */ 1431 if (!vfs_mountroot_try(rootdevnames[0])) 1432 return; 1433 if (!vfs_mountroot_try(rootdevnames[1])) 1434 return; 1435 1436 /* 1437 * If we (still) have a compiled-in default, try it. 1438 */ 1439 if (ctrootdevname != NULL) 1440 if (!vfs_mountroot_try(ctrootdevname)) 1441 return; 1442 /* 1443 * Everything so far has failed, prompt on the console if we haven't 1444 * already tried that. 1445 */ 1446 if (!asked) 1447 if (!vfs_mountroot_ask()) 1448 return; 1449 1450 panic("Root mount failed, startup aborted."); 1451} 1452 1453/* 1454 * Mount (mountfrom) as the root filesystem. 1455 */ 1456static int 1457vfs_mountroot_try(const char *mountfrom) 1458{ 1459 struct mount *mp; 1460 char *vfsname, *path; 1461 time_t timebase; 1462 int error; 1463 char patt[32]; 1464 1465 vfsname = NULL; 1466 path = NULL; 1467 mp = NULL; 1468 error = EINVAL; 1469 1470 if (mountfrom == NULL) 1471 return (error); /* don't complain */ 1472 printf("Trying to mount root from %s\n", mountfrom); 1473 1474 /* parse vfs name and path */ 1475 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1476 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1477 vfsname[0] = path[0] = 0; 1478 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1479 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1480 goto out; 1481 1482 if (path[0] == '\0') 1483 strcpy(path, ROOTNAME); 1484 1485 error = kernel_vmount( 1486 MNT_RDONLY | MNT_ROOTFS, 1487 "fstype", vfsname, 1488 "fspath", "/", 1489 "from", path, 1490 NULL); 1491 if (error == 0) { 1492 /* 1493 * We mount devfs prior to mounting the / FS, so the first 1494 * entry will typically be devfs. 1495 */ 1496 mp = TAILQ_FIRST(&mountlist); 1497 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1498 1499 /* 1500 * Iterate over all currently mounted file systems and use 1501 * the time stamp found to check and/or initialize the RTC. 1502 * Typically devfs has no time stamp and the only other FS 1503 * is the actual / FS. 1504 * Call inittodr() only once and pass it the largest of the 1505 * timestamps we encounter. 1506 */ 1507 timebase = 0; 1508 do { 1509 if (mp->mnt_time > timebase) 1510 timebase = mp->mnt_time; 1511 mp = TAILQ_NEXT(mp, mnt_list); 1512 } while (mp != NULL); 1513 inittodr(timebase); 1514 1515 devfs_fixup(curthread); 1516 } 1517out: 1518 free(path, M_MOUNT); 1519 free(vfsname, M_MOUNT); 1520 return (error); 1521} 1522 1523/* 1524 * --------------------------------------------------------------------- 1525 * Interactive root filesystem selection code. 1526 */ 1527 1528static int 1529vfs_mountroot_ask(void) 1530{ 1531 char name[128]; 1532 1533 for(;;) { 1534 printf("\nManual root filesystem specification:\n"); 1535 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1536#if defined(__amd64__) || defined(__i386__) || defined(__ia64__) 1537 printf(" eg. ufs:da0s1a\n"); 1538#else 1539 printf(" eg. ufs:/dev/da0a\n"); 1540#endif 1541 printf(" ? List valid disk boot devices\n"); 1542 printf(" <empty line> Abort manual input\n"); 1543 printf("\nmountroot> "); 1544 gets(name, sizeof(name), 1); 1545 if (name[0] == '\0') 1546 return (1); 1547 if (name[0] == '?') { 1548 printf("\nList of GEOM managed disk devices:\n "); 1549 g_dev_print(); 1550 continue; 1551 } 1552 if (!vfs_mountroot_try(name)) 1553 return (0); 1554 } 1555} 1556 1557/* 1558 * --------------------------------------------------------------------- 1559 * Functions for querying mount options/arguments from filesystems. 1560 */ 1561 1562/* 1563 * Check that no unknown options are given 1564 */ 1565int 1566vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1567{ 1568 struct vfsopt *opt; 1569 const char **t, *p; 1570 1571 1572 TAILQ_FOREACH(opt, opts, link) { 1573 p = opt->name; 1574 if (p[0] == 'n' && p[1] == 'o') 1575 p += 2; 1576 for(t = global_opts; *t != NULL; t++) 1577 if (!strcmp(*t, p)) 1578 break; 1579 if (*t != NULL) 1580 continue; 1581 for(t = legal; *t != NULL; t++) 1582 if (!strcmp(*t, p)) 1583 break; 1584 if (*t != NULL) 1585 continue; 1586 printf("mount option <%s> is unknown\n", p); 1587 return (EINVAL); 1588 } 1589 return (0); 1590} 1591 1592/* 1593 * Get a mount option by its name. 1594 * 1595 * Return 0 if the option was found, ENOENT otherwise. 1596 * If len is non-NULL it will be filled with the length 1597 * of the option. If buf is non-NULL, it will be filled 1598 * with the address of the option. 1599 */ 1600int 1601vfs_getopt(opts, name, buf, len) 1602 struct vfsoptlist *opts; 1603 const char *name; 1604 void **buf; 1605 int *len; 1606{ 1607 struct vfsopt *opt; 1608 1609 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1610 1611 TAILQ_FOREACH(opt, opts, link) { 1612 if (strcmp(name, opt->name) == 0) { 1613 if (len != NULL) 1614 *len = opt->len; 1615 if (buf != NULL) 1616 *buf = opt->value; 1617 return (0); 1618 } 1619 } 1620 return (ENOENT); 1621} 1622 1623static int 1624vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1625{ 1626 struct vfsopt *opt; 1627 int i; 1628 1629 if (opts == NULL) 1630 return (-1); 1631 1632 i = 0; 1633 TAILQ_FOREACH(opt, opts, link) { 1634 if (strcmp(name, opt->name) == 0) 1635 return (i); 1636 ++i; 1637 } 1638 return (-1); 1639} 1640 1641char * 1642vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1643{ 1644 struct vfsopt *opt; 1645 1646 *error = 0; 1647 TAILQ_FOREACH(opt, opts, link) { 1648 if (strcmp(name, opt->name) != 0) 1649 continue; 1650 if (((char *)opt->value)[opt->len - 1] != '\0') { 1651 *error = EINVAL; 1652 return (NULL); 1653 } 1654 return (opt->value); 1655 } 1656 return (NULL); 1657} 1658 1659int 1660vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1661{ 1662 struct vfsopt *opt; 1663 1664 TAILQ_FOREACH(opt, opts, link) { 1665 if (strcmp(name, opt->name) == 0) { 1666 if (w != NULL) 1667 *w |= val; 1668 return (1); 1669 } 1670 } 1671 if (w != NULL) 1672 *w &= ~val; 1673 return (0); 1674} 1675 1676int 1677vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1678{ 1679 va_list ap; 1680 struct vfsopt *opt; 1681 int ret; 1682 1683 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1684 1685 TAILQ_FOREACH(opt, opts, link) { 1686 if (strcmp(name, opt->name) != 0) 1687 continue; 1688 if (((char *)opt->value)[opt->len - 1] != '\0') 1689 return (0); 1690 va_start(ap, fmt); 1691 ret = vsscanf(opt->value, fmt, ap); 1692 va_end(ap); 1693 return (ret); 1694 } 1695 return (0); 1696} 1697 1698/* 1699 * Find and copy a mount option. 1700 * 1701 * The size of the buffer has to be specified 1702 * in len, if it is not the same length as the 1703 * mount option, EINVAL is returned. 1704 * Returns ENOENT if the option is not found. 1705 */ 1706int 1707vfs_copyopt(opts, name, dest, len) 1708 struct vfsoptlist *opts; 1709 const char *name; 1710 void *dest; 1711 int len; 1712{ 1713 struct vfsopt *opt; 1714 1715 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1716 1717 TAILQ_FOREACH(opt, opts, link) { 1718 if (strcmp(name, opt->name) == 0) { 1719 if (len != opt->len) 1720 return (EINVAL); 1721 bcopy(opt->value, dest, opt->len); 1722 return (0); 1723 } 1724 } 1725 return (ENOENT); 1726} 1727 1728/* 1729 * This is a helper function for filesystems to traverse their 1730 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1731 */ 1732 1733struct vnode * 1734__mnt_vnode_next(struct vnode **mvp, struct mount *mp) 1735{ 1736 struct vnode *vp; 1737 1738 mtx_assert(MNT_MTX(mp), MA_OWNED); 1739 1740 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 1741 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 1742 while (vp != NULL && vp->v_type == VMARKER) 1743 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1744 1745 /* Check if we are done */ 1746 if (vp == NULL) { 1747 __mnt_vnode_markerfree(mvp, mp); 1748 return (NULL); 1749 } 1750 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 1751 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1752 return (vp); 1753} 1754 1755struct vnode * 1756__mnt_vnode_first(struct vnode **mvp, struct mount *mp) 1757{ 1758 struct vnode *vp; 1759 1760 mtx_assert(MNT_MTX(mp), MA_OWNED); 1761 1762 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1763 while (vp != NULL && vp->v_type == VMARKER) 1764 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1765 1766 /* Check if we are done */ 1767 if (vp == NULL) { 1768 *mvp = NULL; 1769 return (NULL); 1770 } 1771 mp->mnt_holdcnt++; 1772 MNT_IUNLOCK(mp); 1773 *mvp = (struct vnode *) malloc(sizeof(struct vnode), 1774 M_VNODE_MARKER, 1775 M_WAITOK | M_ZERO); 1776 MNT_ILOCK(mp); 1777 (*mvp)->v_type = VMARKER; 1778 1779 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1780 while (vp != NULL && vp->v_type == VMARKER) 1781 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1782 1783 /* Check if we are done */ 1784 if (vp == NULL) { 1785 MNT_IUNLOCK(mp); 1786 free(*mvp, M_VNODE_MARKER); 1787 MNT_ILOCK(mp); 1788 *mvp = NULL; 1789 mp->mnt_holdcnt--; 1790 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 1791 wakeup(&mp->mnt_holdcnt); 1792 return (NULL); 1793 } 1794 mp->mnt_markercnt++; 1795 (*mvp)->v_mount = mp; 1796 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1797 return (vp); 1798} 1799 1800 1801void 1802__mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp) 1803{ 1804 1805 if (*mvp == NULL) 1806 return; 1807 1808 mtx_assert(MNT_MTX(mp), MA_OWNED); 1809 1810 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 1811 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 1812 MNT_IUNLOCK(mp); 1813 free(*mvp, M_VNODE_MARKER); 1814 MNT_ILOCK(mp); 1815 *mvp = NULL; 1816 1817 mp->mnt_markercnt--; 1818 mp->mnt_holdcnt--; 1819 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 1820 wakeup(&mp->mnt_holdcnt); 1821} 1822 1823 1824int 1825__vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 1826{ 1827 int error; 1828 1829 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 1830 if (sbp != &mp->mnt_stat) 1831 *sbp = mp->mnt_stat; 1832 return (error); 1833} 1834 1835void 1836vfs_mountedfrom(struct mount *mp, const char *from) 1837{ 1838 1839 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 1840 strlcpy(mp->mnt_stat.f_mntfromname, from, 1841 sizeof mp->mnt_stat.f_mntfromname); 1842} 1843 1844/* 1845 * --------------------------------------------------------------------- 1846 * This is the api for building mount args and mounting filesystems from 1847 * inside the kernel. 1848 * 1849 * The API works by accumulation of individual args. First error is 1850 * latched. 1851 * 1852 * XXX: should be documented in new manpage kernel_mount(9) 1853 */ 1854 1855/* A memory allocation which must be freed when we are done */ 1856struct mntaarg { 1857 SLIST_ENTRY(mntaarg) next; 1858}; 1859 1860/* The header for the mount arguments */ 1861struct mntarg { 1862 struct iovec *v; 1863 int len; 1864 int error; 1865 SLIST_HEAD(, mntaarg) list; 1866}; 1867 1868/* 1869 * Add a boolean argument. 1870 * 1871 * flag is the boolean value. 1872 * name must start with "no". 1873 */ 1874struct mntarg * 1875mount_argb(struct mntarg *ma, int flag, const char *name) 1876{ 1877 1878 KASSERT(name[0] == 'n' && name[1] == 'o', 1879 ("mount_argb(...,%s): name must start with 'no'", name)); 1880 1881 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 1882} 1883 1884/* 1885 * Add an argument printf style 1886 */ 1887struct mntarg * 1888mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 1889{ 1890 va_list ap; 1891 struct mntaarg *maa; 1892 struct sbuf *sb; 1893 int len; 1894 1895 if (ma == NULL) { 1896 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 1897 SLIST_INIT(&ma->list); 1898 } 1899 if (ma->error) 1900 return (ma); 1901 1902 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 1903 M_MOUNT, M_WAITOK); 1904 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 1905 ma->v[ma->len].iov_len = strlen(name) + 1; 1906 ma->len++; 1907 1908 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 1909 va_start(ap, fmt); 1910 sbuf_vprintf(sb, fmt, ap); 1911 va_end(ap); 1912 sbuf_finish(sb); 1913 len = sbuf_len(sb) + 1; 1914 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 1915 SLIST_INSERT_HEAD(&ma->list, maa, next); 1916 bcopy(sbuf_data(sb), maa + 1, len); 1917 sbuf_delete(sb); 1918 1919 ma->v[ma->len].iov_base = maa + 1; 1920 ma->v[ma->len].iov_len = len; 1921 ma->len++; 1922 1923 return (ma); 1924} 1925 1926/* 1927 * Add an argument which is a userland string. 1928 */ 1929struct mntarg * 1930mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 1931{ 1932 struct mntaarg *maa; 1933 char *tbuf; 1934 1935 if (val == NULL) 1936 return (ma); 1937 if (ma == NULL) { 1938 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 1939 SLIST_INIT(&ma->list); 1940 } 1941 if (ma->error) 1942 return (ma); 1943 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 1944 SLIST_INSERT_HEAD(&ma->list, maa, next); 1945 tbuf = (void *)(maa + 1); 1946 ma->error = copyinstr(val, tbuf, len, NULL); 1947 return (mount_arg(ma, name, tbuf, -1)); 1948} 1949 1950/* 1951 * Plain argument. 1952 * 1953 * If length is -1, use printf. 1954 */ 1955struct mntarg * 1956mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 1957{ 1958 1959 if (ma == NULL) { 1960 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 1961 SLIST_INIT(&ma->list); 1962 } 1963 if (ma->error) 1964 return (ma); 1965 1966 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 1967 M_MOUNT, M_WAITOK); 1968 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 1969 ma->v[ma->len].iov_len = strlen(name) + 1; 1970 ma->len++; 1971 1972 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 1973 if (len < 0) 1974 ma->v[ma->len].iov_len = strlen(val) + 1; 1975 else 1976 ma->v[ma->len].iov_len = len; 1977 ma->len++; 1978 return (ma); 1979} 1980 1981/* 1982 * Free a mntarg structure 1983 */ 1984static void 1985free_mntarg(struct mntarg *ma) 1986{ 1987 struct mntaarg *maa; 1988 1989 while (!SLIST_EMPTY(&ma->list)) { 1990 maa = SLIST_FIRST(&ma->list); 1991 SLIST_REMOVE_HEAD(&ma->list, next); 1992 free(maa, M_MOUNT); 1993 } 1994 free(ma->v, M_MOUNT); 1995 free(ma, M_MOUNT); 1996} 1997 1998/* 1999 * Mount a filesystem 2000 */ 2001int 2002kernel_mount(struct mntarg *ma, int flags) 2003{ 2004 struct uio auio; 2005 int error; 2006 2007 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2008 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2009 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2010 2011 auio.uio_iov = ma->v; 2012 auio.uio_iovcnt = ma->len; 2013 auio.uio_segflg = UIO_SYSSPACE; 2014 2015 error = ma->error; 2016 if (!error) 2017 error = vfs_donmount(curthread, flags, &auio); 2018 free_mntarg(ma); 2019 return (error); 2020} 2021 2022/* 2023 * A printflike function to mount a filesystem. 2024 */ 2025int 2026kernel_vmount(int flags, ...) 2027{ 2028 struct mntarg *ma = NULL; 2029 va_list ap; 2030 const char *cp; 2031 const void *vp; 2032 int error; 2033 2034 va_start(ap, flags); 2035 for (;;) { 2036 cp = va_arg(ap, const char *); 2037 if (cp == NULL) 2038 break; 2039 vp = va_arg(ap, const void *); 2040 ma = mount_arg(ma, cp, vp, -1); 2041 } 2042 va_end(ap); 2043 2044 error = kernel_mount(ma, flags); 2045 return (error); 2046} 2047