vfs_mount.c revision 138357
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 138357 2004-12-03 19:25:44Z phk $"); 63 64#include <sys/param.h> 65#include <sys/conf.h> 66#include <sys/cons.h> 67#include <sys/jail.h> 68#include <sys/kernel.h> 69#include <sys/mac.h> 70#include <sys/malloc.h> 71#include <sys/mount.h> 72#include <sys/mutex.h> 73#include <sys/namei.h> 74#include <sys/proc.h> 75#include <sys/filedesc.h> 76#include <sys/reboot.h> 77#include <sys/sysproto.h> 78#include <sys/sx.h> 79#include <sys/sysctl.h> 80#include <sys/sysent.h> 81#include <sys/systm.h> 82#include <sys/vnode.h> 83 84#include <geom/geom.h> 85 86#include <machine/stdarg.h> 87 88#include "opt_rootdevname.h" 89#include "opt_ddb.h" 90#include "opt_mac.h" 91 92#ifdef DDB 93#include <ddb/ddb.h> 94#endif 95 96#define ROOTNAME "root_device" 97#define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 98 99static void checkdirs(struct vnode *olddp, struct vnode *newdp); 100static struct cdev *getdiskbyname(char *_name); 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 /* Kick out MNT_ROOTFS early as it is legal internally */ 393 if (uap->flags & MNT_ROOTFS) 394 return (EINVAL); 395 396 iovcnt = uap->iovcnt; 397 /* 398 * Check that we have an even number of iovec's 399 * and that we have at least two options. 400 */ 401 if ((iovcnt & 1) || (iovcnt < 4)) 402 return (EINVAL); 403 404 error = copyinuio(uap->iovp, iovcnt, &auio); 405 if (error) 406 return (error); 407 iov = auio->uio_iov; 408 for (i = 0; i < iovcnt; i++) { 409 if (iov->iov_len > MMAXOPTIONLEN) { 410 free(auio, M_IOV); 411 return (EINVAL); 412 } 413 iov++; 414 } 415 error = vfs_donmount(td, uap->flags, auio); 416 free(auio, M_IOV); 417 return (error); 418} 419 420int 421kernel_mount(struct iovec *iovp, u_int iovcnt, int flags) 422{ 423 struct uio auio; 424 int error; 425 426 /* 427 * Check that we have an even number of iovec's 428 * and that we have at least two options. 429 */ 430 if ((iovcnt & 1) || (iovcnt < 4)) 431 return (EINVAL); 432 433 auio.uio_iov = iovp; 434 auio.uio_iovcnt = iovcnt; 435 auio.uio_segflg = UIO_SYSSPACE; 436 437 error = vfs_donmount(curthread, flags, &auio); 438 return (error); 439} 440 441int 442kernel_vmount(int flags, ...) 443{ 444 struct iovec *iovp; 445 struct uio auio; 446 va_list ap; 447 u_int iovcnt, iovlen, len; 448 const char *cp; 449 char *buf, *pos; 450 size_t n; 451 int error, i; 452 453 len = 0; 454 va_start(ap, flags); 455 for (iovcnt = 0; (cp = va_arg(ap, const char *)) != NULL; iovcnt++) 456 len += strlen(cp) + 1; 457 va_end(ap); 458 459 if (iovcnt < 4 || iovcnt & 1) 460 return (EINVAL); 461 462 iovlen = iovcnt * sizeof (struct iovec); 463 MALLOC(iovp, struct iovec *, iovlen, M_MOUNT, M_WAITOK); 464 MALLOC(buf, char *, len, M_MOUNT, M_WAITOK); 465 pos = buf; 466 va_start(ap, flags); 467 for (i = 0; i < iovcnt; i++) { 468 cp = va_arg(ap, const char *); 469 copystr(cp, pos, len - (pos - buf), &n); 470 iovp[i].iov_base = pos; 471 iovp[i].iov_len = n; 472 pos += n; 473 } 474 va_end(ap); 475 476 auio.uio_iov = iovp; 477 auio.uio_iovcnt = iovcnt; 478 auio.uio_segflg = UIO_SYSSPACE; 479 480 error = vfs_donmount(curthread, flags, &auio); 481 FREE(iovp, M_MOUNT); 482 FREE(buf, M_MOUNT); 483 return (error); 484} 485 486/* 487 * Allocate and initialize the mount point struct. 488 */ 489static int 490vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 491 const char *fspath, struct thread *td, struct mount **mpp) 492{ 493 struct mount *mp; 494 495 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 496 TAILQ_INIT(&mp->mnt_nvnodelist); 497 mp->mnt_nvnodelistsize = 0; 498 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 499 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 500 vfs_busy(mp, LK_NOWAIT, 0, td); 501 mp->mnt_op = vfsp->vfc_vfsops; 502 mp->mnt_vfc = vfsp; 503 vfsp->vfc_refcount++; 504 mp->mnt_stat.f_type = vfsp->vfc_typenum; 505 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 506 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 507 mp->mnt_vnodecovered = vp; 508 mp->mnt_cred = crdup(td->td_ucred); 509 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 510 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 511 mp->mnt_iosize_max = DFLTPHYS; 512#ifdef MAC 513 mac_init_mount(mp); 514 mac_create_mount(td->td_ucred, mp); 515#endif 516 *mpp = mp; 517 return (0); 518} 519 520/* 521 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 522 */ 523void 524vfs_mount_destroy(struct mount *mp, struct thread *td) 525{ 526 527 mp->mnt_vfc->vfc_refcount--; 528 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 529 panic("unmount: dangling vnode"); 530 vfs_unbusy(mp,td); 531 lockdestroy(&mp->mnt_lock); 532 mtx_destroy(&mp->mnt_mtx); 533 if (mp->mnt_kern_flag & MNTK_MWAIT) 534 wakeup(mp); 535#ifdef MAC 536 mac_destroy_mount(mp); 537#endif 538 if (mp->mnt_opt != NULL) 539 vfs_freeopts(mp->mnt_opt); 540 crfree(mp->mnt_cred); 541 free(mp, M_MOUNT); 542} 543 544static int 545vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 546{ 547 struct vfsoptlist *optlist; 548 char *fstype, *fspath; 549 int error, fstypelen, fspathlen; 550 551 error = vfs_buildopts(fsoptions, &optlist); 552 if (error) 553 return (error); 554 555 /* 556 * We need these two options before the others, 557 * and they are mandatory for any filesystem. 558 * Ensure they are NUL terminated as well. 559 */ 560 fstypelen = 0; 561 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 562 if (error || fstype[fstypelen - 1] != '\0') { 563 error = EINVAL; 564 goto bail; 565 } 566 fspathlen = 0; 567 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 568 if (error || fspath[fspathlen - 1] != '\0') { 569 error = EINVAL; 570 goto bail; 571 } 572 573 /* 574 * Be ultra-paranoid about making sure the type and fspath 575 * variables will fit in our mp buffers, including the 576 * terminating NUL. 577 */ 578 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 579 error = ENAMETOOLONG; 580 goto bail; 581 } 582 583 mtx_lock(&Giant); 584 error = vfs_domount(td, fstype, fspath, fsflags, optlist, 0); 585 mtx_unlock(&Giant); 586bail: 587 if (error) 588 vfs_freeopts(optlist); 589 return (error); 590} 591 592/* 593 * Old mount API. 594 */ 595#ifndef _SYS_SYSPROTO_H_ 596struct mount_args { 597 char *type; 598 char *path; 599 int flags; 600 caddr_t data; 601}; 602#endif 603/* ARGSUSED */ 604int 605mount(td, uap) 606 struct thread *td; 607 struct mount_args /* { 608 char *type; 609 char *path; 610 int flags; 611 caddr_t data; 612 } */ *uap; 613{ 614 char *fstype; 615 char *fspath; 616 int error; 617 618 /* Kick out MNT_ROOTFS early as it is legal internally */ 619 if (uap->flags & MNT_ROOTFS) 620 return (EINVAL); 621 622 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 623 fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK); 624 625 /* 626 * vfs_mount() actually takes a kernel string for `type' and 627 * `path' now, so extract them. 628 */ 629 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 630 if (error == 0) 631 error = copyinstr(uap->path, fspath, MNAMELEN, NULL); 632 if (error == 0) { 633 mtx_lock(&Giant); 634 error = vfs_domount(td, fstype, fspath, uap->flags, 635 uap->data, 1); 636 mtx_unlock(&Giant); 637 } 638 free(fstype, M_TEMP); 639 free(fspath, M_TEMP); 640 return (error); 641} 642 643/* 644 * vfs_domount(): actually attempt a filesystem mount. 645 */ 646static int 647vfs_domount( 648 struct thread *td, /* Flags common to all filesystems. */ 649 const char *fstype, /* Filesystem type. */ 650 char *fspath, /* Mount path. */ 651 int fsflags, /* Flags common to all filesystems. */ 652 void *fsdata, /* Options local to the filesystem. */ 653 int compat /* Invocation from compat syscall. */ 654 ) 655{ 656 struct vnode *vp; 657 struct mount *mp; 658 struct vfsconf *vfsp; 659 int error, flag = 0, kern_flag = 0; 660 struct vattr va; 661 struct nameidata nd; 662 663 mtx_assert(&Giant, MA_OWNED); 664 665 /* 666 * Be ultra-paranoid about making sure the type and fspath 667 * variables will fit in our mp buffers, including the 668 * terminating NUL. 669 */ 670 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 671 return (ENAMETOOLONG); 672 673 if (jailed(td->td_ucred)) 674 return (EPERM); 675 if (usermount == 0) { 676 if ((error = suser(td)) != 0) 677 return (error); 678 } 679 680 /* 681 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 682 */ 683 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 684 if ((error = suser(td)) != 0) 685 return (error); 686 } 687 /* 688 * Silently enforce MNT_NOSUID and MNT_USER for 689 * unprivileged users. 690 */ 691 if (suser(td) != 0) 692 fsflags |= MNT_NOSUID | MNT_USER; 693 /* 694 * Get vnode to be covered 695 */ 696 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 697 if ((error = namei(&nd)) != 0) 698 return (error); 699 NDFREE(&nd, NDF_ONLY_PNBUF); 700 vp = nd.ni_vp; 701 if (fsflags & MNT_UPDATE) { 702 if ((vp->v_vflag & VV_ROOT) == 0) { 703 vput(vp); 704 return (EINVAL); 705 } 706 mp = vp->v_mount; 707 flag = mp->mnt_flag; 708 kern_flag = mp->mnt_kern_flag; 709 /* 710 * We only allow the filesystem to be reloaded if it 711 * is currently mounted read-only. 712 */ 713 if ((fsflags & MNT_RELOAD) && 714 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 715 vput(vp); 716 return (EOPNOTSUPP); /* Needs translation */ 717 } 718 /* 719 * Only privileged root, or (if MNT_USER is set) the user that 720 * did the original mount is permitted to update it. 721 */ 722 error = vfs_suser(mp, td); 723 if (error) { 724 vput(vp); 725 return (error); 726 } 727 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 728 vput(vp); 729 return (EBUSY); 730 } 731 VI_LOCK(vp); 732 if ((vp->v_iflag & VI_MOUNT) != 0 || 733 vp->v_mountedhere != NULL) { 734 VI_UNLOCK(vp); 735 vfs_unbusy(mp, td); 736 vput(vp); 737 return (EBUSY); 738 } 739 vp->v_iflag |= VI_MOUNT; 740 VI_UNLOCK(vp); 741 mp->mnt_flag |= fsflags & 742 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT); 743 VOP_UNLOCK(vp, 0, td); 744 if (compat == 0) { 745 mp->mnt_optnew = fsdata; 746 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 747 } 748 } else { 749 /* 750 * If the user is not root, ensure that they own the directory 751 * onto which we are attempting to mount. 752 */ 753 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 754 if (error) { 755 vput(vp); 756 return (error); 757 } 758 if (va.va_uid != td->td_ucred->cr_uid) { 759 if ((error = suser(td)) != 0) { 760 vput(vp); 761 return (error); 762 } 763 } 764 if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) { 765 vput(vp); 766 return (error); 767 } 768 if (vp->v_type != VDIR) { 769 vput(vp); 770 return (ENOTDIR); 771 } 772 vfsp = vfs_byname_kld(fstype, td, &error); 773 if (vfsp == NULL) { 774 vput(vp); 775 return (error); 776 } 777 VI_LOCK(vp); 778 if ((vp->v_iflag & VI_MOUNT) != 0 || 779 vp->v_mountedhere != NULL) { 780 VI_UNLOCK(vp); 781 vput(vp); 782 return (EBUSY); 783 } 784 vp->v_iflag |= VI_MOUNT; 785 VI_UNLOCK(vp); 786 787 /* 788 * Allocate and initialize the filesystem. 789 */ 790 error = vfs_mount_alloc(vp, vfsp, fspath, td, &mp); 791 if (error) { 792 vput(vp); 793 return (error); 794 } 795 VOP_UNLOCK(vp, 0, td); 796 797 /* XXXMAC: pass to vfs_mount_alloc? */ 798 if (compat == 0) 799 mp->mnt_optnew = fsdata; 800 } 801 /* 802 * Check if the fs implements the type VFS_[O]MOUNT() 803 * function we are looking for. 804 */ 805 if ((compat && (mp->mnt_op->vfs_omount == NULL)) || 806 (!compat && (mp->mnt_op->vfs_mount == NULL))) { 807 printf("%s doesn't support the %s mount syscall\n", 808 mp->mnt_vfc->vfc_name, compat ? "old" : "new"); 809 VI_LOCK(vp); 810 vp->v_iflag &= ~VI_MOUNT; 811 VI_UNLOCK(vp); 812 if (mp->mnt_flag & MNT_UPDATE) 813 vfs_unbusy(mp, td); 814 else 815 vfs_mount_destroy(mp, td); 816 vrele(vp); 817 return (EOPNOTSUPP); 818 } 819 820 /* 821 * Set the mount level flags. 822 */ 823 if (fsflags & MNT_RDONLY) 824 mp->mnt_flag |= MNT_RDONLY; 825 else if (mp->mnt_flag & MNT_RDONLY) 826 mp->mnt_kern_flag |= MNTK_WANTRDWR; 827 mp->mnt_flag &=~ MNT_UPDATEMASK; 828 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE); 829 /* 830 * Mount the filesystem. 831 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 832 * get. No freeing of cn_pnbuf. 833 */ 834 if (compat) 835 error = VFS_OMOUNT(mp, fspath, fsdata, td); 836 else 837 error = VFS_MOUNT(mp, td); 838 if (!error) { 839 if (mp->mnt_opt != NULL) 840 vfs_freeopts(mp->mnt_opt); 841 mp->mnt_opt = mp->mnt_optnew; 842 } 843 /* 844 * Prevent external consumers of mount options from reading 845 * mnt_optnew. 846 */ 847 mp->mnt_optnew = NULL; 848 if (mp->mnt_flag & MNT_UPDATE) { 849 if (mp->mnt_kern_flag & MNTK_WANTRDWR) 850 mp->mnt_flag &= ~MNT_RDONLY; 851 mp->mnt_flag &= 852 ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 853 mp->mnt_kern_flag &= ~MNTK_WANTRDWR; 854 if (error) { 855 mp->mnt_flag = flag; 856 mp->mnt_kern_flag = kern_flag; 857 } 858 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 859 if (mp->mnt_syncer == NULL) 860 error = vfs_allocate_syncvnode(mp); 861 } else { 862 if (mp->mnt_syncer != NULL) 863 vrele(mp->mnt_syncer); 864 mp->mnt_syncer = NULL; 865 } 866 vfs_unbusy(mp, td); 867 VI_LOCK(vp); 868 vp->v_iflag &= ~VI_MOUNT; 869 VI_UNLOCK(vp); 870 vrele(vp); 871 return (error); 872 } 873 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 874 /* 875 * Put the new filesystem on the mount list after root. 876 */ 877 cache_purge(vp); 878 if (!error) { 879 struct vnode *newdp; 880 881 VI_LOCK(vp); 882 vp->v_iflag &= ~VI_MOUNT; 883 VI_UNLOCK(vp); 884 vp->v_mountedhere = mp; 885 mtx_lock(&mountlist_mtx); 886 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 887 mtx_unlock(&mountlist_mtx); 888 vfs_event_signal(NULL, VQ_MOUNT, 0); 889 if (VFS_ROOT(mp, &newdp, td)) 890 panic("mount: lost mount"); 891 checkdirs(vp, newdp); 892 vput(newdp); 893 VOP_UNLOCK(vp, 0, td); 894 if ((mp->mnt_flag & MNT_RDONLY) == 0) 895 error = vfs_allocate_syncvnode(mp); 896 vfs_unbusy(mp, td); 897 if (error || (error = VFS_START(mp, 0, td)) != 0) 898 vrele(vp); 899 } else { 900 VI_LOCK(vp); 901 vp->v_iflag &= ~VI_MOUNT; 902 VI_UNLOCK(vp); 903 vfs_mount_destroy(mp, td); 904 vput(vp); 905 } 906 return (error); 907} 908 909/* 910 * Scan all active processes to see if any of them have a current 911 * or root directory of `olddp'. If so, replace them with the new 912 * mount point. 913 */ 914static void 915checkdirs(olddp, newdp) 916 struct vnode *olddp, *newdp; 917{ 918 struct filedesc *fdp; 919 struct proc *p; 920 int nrele; 921 922 if (vrefcnt(olddp) == 1) 923 return; 924 sx_slock(&allproc_lock); 925 LIST_FOREACH(p, &allproc, p_list) { 926 mtx_lock(&fdesc_mtx); 927 fdp = p->p_fd; 928 if (fdp == NULL) { 929 mtx_unlock(&fdesc_mtx); 930 continue; 931 } 932 nrele = 0; 933 FILEDESC_LOCK_FAST(fdp); 934 if (fdp->fd_cdir == olddp) { 935 vref(newdp); 936 fdp->fd_cdir = newdp; 937 nrele++; 938 } 939 if (fdp->fd_rdir == olddp) { 940 vref(newdp); 941 fdp->fd_rdir = newdp; 942 nrele++; 943 } 944 FILEDESC_UNLOCK_FAST(fdp); 945 mtx_unlock(&fdesc_mtx); 946 while (nrele--) 947 vrele(olddp); 948 } 949 sx_sunlock(&allproc_lock); 950 if (rootvnode == olddp) { 951 vrele(rootvnode); 952 vref(newdp); 953 rootvnode = newdp; 954 } 955} 956 957/* 958 * Unmount a filesystem. 959 * 960 * Note: unmount takes a path to the vnode mounted on as argument, 961 * not special file (as before). 962 */ 963#ifndef _SYS_SYSPROTO_H_ 964struct unmount_args { 965 char *path; 966 int flags; 967}; 968#endif 969/* ARGSUSED */ 970int 971unmount(td, uap) 972 struct thread *td; 973 register struct unmount_args /* { 974 char *path; 975 int flags; 976 } */ *uap; 977{ 978 struct mount *mp; 979 char *pathbuf; 980 int error, id0, id1; 981 982 if (jailed(td->td_ucred)) 983 return (EPERM); 984 if (usermount == 0) { 985 if ((error = suser(td)) != 0) 986 return (error); 987 } 988 989 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 990 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 991 if (error) { 992 free(pathbuf, M_TEMP); 993 return (error); 994 } 995 if (uap->flags & MNT_BYFSID) { 996 /* Decode the filesystem ID. */ 997 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 998 free(pathbuf, M_TEMP); 999 return (EINVAL); 1000 } 1001 1002 mtx_lock(&mountlist_mtx); 1003 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1004 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1005 mp->mnt_stat.f_fsid.val[1] == id1) 1006 break; 1007 } 1008 mtx_unlock(&mountlist_mtx); 1009 } else { 1010 mtx_lock(&mountlist_mtx); 1011 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1012 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1013 break; 1014 } 1015 mtx_unlock(&mountlist_mtx); 1016 } 1017 free(pathbuf, M_TEMP); 1018 if (mp == NULL) { 1019 /* 1020 * Previously we returned ENOENT for a nonexistent path and 1021 * EINVAL for a non-mountpoint. We cannot tell these apart 1022 * now, so in the !MNT_BYFSID case return the more likely 1023 * EINVAL for compatibility. 1024 */ 1025 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1026 } 1027 1028 /* 1029 * Only privileged root, or (if MNT_USER is set) the user that did the 1030 * original mount is permitted to unmount this filesystem. 1031 */ 1032 error = vfs_suser(mp, td); 1033 if (error) 1034 return (error); 1035 1036 /* 1037 * Don't allow unmounting the root filesystem. 1038 */ 1039 if (mp->mnt_flag & MNT_ROOTFS) 1040 return (EINVAL); 1041 mtx_lock(&Giant); 1042 error = dounmount(mp, uap->flags, td); 1043 mtx_unlock(&Giant); 1044 return (error); 1045} 1046 1047/* 1048 * Do the actual filesystem unmount. 1049 */ 1050int 1051dounmount(mp, flags, td) 1052 struct mount *mp; 1053 int flags; 1054 struct thread *td; 1055{ 1056 struct vnode *coveredvp, *fsrootvp; 1057 int error; 1058 int async_flag; 1059 1060 mtx_assert(&Giant, MA_OWNED); 1061 1062 mtx_lock(&mountlist_mtx); 1063 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1064 mtx_unlock(&mountlist_mtx); 1065 return (EBUSY); 1066 } 1067 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1068 /* Allow filesystems to detect that a forced unmount is in progress. */ 1069 if (flags & MNT_FORCE) 1070 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1071 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1072 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); 1073 if (error) { 1074 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1075 if (mp->mnt_kern_flag & MNTK_MWAIT) 1076 wakeup(mp); 1077 return (error); 1078 } 1079 vn_start_write(NULL, &mp, V_WAIT); 1080 1081 if (mp->mnt_flag & MNT_EXPUBLIC) 1082 vfs_setpublicfs(NULL, NULL, NULL); 1083 1084 vfs_msync(mp, MNT_WAIT); 1085 async_flag = mp->mnt_flag & MNT_ASYNC; 1086 mp->mnt_flag &= ~MNT_ASYNC; 1087 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1088 if (mp->mnt_syncer != NULL) 1089 vrele(mp->mnt_syncer); 1090 /* 1091 * For forced unmounts, move process cdir/rdir refs on the fs root 1092 * vnode to the covered vnode. For non-forced unmounts we want 1093 * such references to cause an EBUSY error. 1094 */ 1095 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1096 if (mp->mnt_vnodecovered != NULL) 1097 checkdirs(fsrootvp, mp->mnt_vnodecovered); 1098 if (fsrootvp == rootvnode) { 1099 vrele(rootvnode); 1100 rootvnode = NULL; 1101 } 1102 vput(fsrootvp); 1103 } 1104 if (((mp->mnt_flag & MNT_RDONLY) || 1105 (error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) == 0) || 1106 (flags & MNT_FORCE)) { 1107 error = VFS_UNMOUNT(mp, flags, td); 1108 } 1109 vn_finished_write(mp); 1110 if (error) { 1111 /* Undo cdir/rdir and rootvnode changes made above. */ 1112 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1113 if (mp->mnt_vnodecovered != NULL) 1114 checkdirs(mp->mnt_vnodecovered, fsrootvp); 1115 if (rootvnode == NULL) { 1116 rootvnode = fsrootvp; 1117 vref(rootvnode); 1118 } 1119 vput(fsrootvp); 1120 } 1121 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1122 (void) vfs_allocate_syncvnode(mp); 1123 mtx_lock(&mountlist_mtx); 1124 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1125 mp->mnt_flag |= async_flag; 1126 lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, 1127 &mountlist_mtx, td); 1128 if (mp->mnt_kern_flag & MNTK_MWAIT) 1129 wakeup(mp); 1130 return (error); 1131 } 1132 mtx_lock(&mountlist_mtx); 1133 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1134 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 1135 coveredvp->v_mountedhere = NULL; 1136 mtx_unlock(&mountlist_mtx); 1137 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1138 vfs_mount_destroy(mp, td); 1139 if (coveredvp != NULL) 1140 vrele(coveredvp); 1141 return (0); 1142} 1143 1144/* 1145 * Find and mount the root filesystem 1146 */ 1147void 1148vfs_mountroot(void) 1149{ 1150 char *cp; 1151 int error, i, asked = 0; 1152 1153 1154 /* 1155 * Wait for GEOM to settle down 1156 */ 1157 DROP_GIANT(); 1158 g_waitidle(); 1159 PICKUP_GIANT(); 1160 1161 /* 1162 * We are booted with instructions to prompt for the root filesystem. 1163 */ 1164 if (boothowto & RB_ASKNAME) { 1165 if (!vfs_mountroot_ask()) 1166 return; 1167 asked = 1; 1168 } 1169 1170 /* 1171 * The root filesystem information is compiled in, and we are 1172 * booted with instructions to use it. 1173 */ 1174 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1175 if (!vfs_mountroot_try(ctrootdevname)) 1176 return; 1177 ctrootdevname = NULL; 1178 } 1179 1180 /* 1181 * We've been given the generic "use CDROM as root" flag. This is 1182 * necessary because one media may be used in many different 1183 * devices, so we need to search for them. 1184 */ 1185 if (boothowto & RB_CDROM) { 1186 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1187 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1188 return; 1189 } 1190 } 1191 1192 /* 1193 * Try to use the value read by the loader from /etc/fstab, or 1194 * supplied via some other means. This is the preferred 1195 * mechanism. 1196 */ 1197 cp = getenv("vfs.root.mountfrom"); 1198 if (cp != NULL) { 1199 error = vfs_mountroot_try(cp); 1200 freeenv(cp); 1201 if (!error) 1202 return; 1203 } 1204 1205 /* 1206 * Try values that may have been computed by code during boot 1207 */ 1208 if (!vfs_mountroot_try(rootdevnames[0])) 1209 return; 1210 if (!vfs_mountroot_try(rootdevnames[1])) 1211 return; 1212 1213 /* 1214 * If we (still) have a compiled-in default, try it. 1215 */ 1216 if (ctrootdevname != NULL) 1217 if (!vfs_mountroot_try(ctrootdevname)) 1218 return; 1219 1220 /* 1221 * Everything so far has failed, prompt on the console if we haven't 1222 * already tried that. 1223 */ 1224 if (!asked) 1225 if (!vfs_mountroot_ask()) 1226 return; 1227 panic("Root mount failed, startup aborted."); 1228} 1229 1230/* 1231 * Mount (mountfrom) as the root filesystem. 1232 */ 1233static int 1234vfs_mountroot_try(const char *mountfrom) 1235{ 1236 struct mount *mp; 1237 struct thread *td = curthread; 1238 struct vfsconf *vfsp; 1239 char *vfsname, *path; 1240 int error; 1241 char patt[32]; 1242 int s; 1243 1244 vfsname = NULL; 1245 path = NULL; 1246 mp = NULL; 1247 error = EINVAL; 1248 1249 if (mountfrom == NULL) 1250 return (error); /* don't complain */ 1251 1252 s = splcam(); /* Overkill, but annoying without it */ 1253 printf("Trying to mount root from %s\n", mountfrom); 1254 splx(s); 1255 1256 /* parse vfs name and path */ 1257 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1258 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1259 vfsname[0] = path[0] = 0; 1260 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1261 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1262 goto done; 1263 1264 if (path[0] == '\0') 1265 strcpy(path, ROOTNAME); 1266 1267 vfsp = vfs_byname(vfsname); 1268 if (vfsp == NULL) { 1269 printf("Can't find filesystem \"%s\"\n", vfsname); 1270 goto done; 1271 } 1272 error = vfs_mount_alloc(NULLVP, vfsp, "/", td, &mp); 1273 if (error) { 1274 printf("Could not alloc mountpoint\n"); 1275 goto done; 1276 } 1277 1278 mp->mnt_flag |= MNT_RDONLY | MNT_ROOTFS; 1279 1280 strlcpy(mp->mnt_stat.f_mntfromname, path, MNAMELEN); 1281 1282 /* 1283 * do our best to set rootdev 1284 * XXX: This does not belong here! 1285 */ 1286 if (path[0] != '\0') { 1287 struct cdev *diskdev; 1288 diskdev = getdiskbyname(path); 1289 if (diskdev != NULL) 1290 rootdev = diskdev; 1291 else 1292 printf("setrootbyname failed\n"); 1293 } 1294 1295 error = VFS_OMOUNT(mp, path, NULL, curthread); 1296 1297done: 1298 if (vfsname != NULL) 1299 free(vfsname, M_MOUNT); 1300 if (path != NULL) 1301 free(path, M_MOUNT); 1302 if (error != 0) { 1303 if (mp != NULL) 1304 vfs_mount_destroy(mp, curthread); 1305 printf("Root mount failed: %d\n", error); 1306 } else { 1307 1308 /* register with list of mounted filesystems */ 1309 mtx_lock(&mountlist_mtx); 1310 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1311 mtx_unlock(&mountlist_mtx); 1312 1313 /* sanity check system clock against root fs timestamp */ 1314 inittodr(mp->mnt_time); 1315 vfs_unbusy(mp, curthread); 1316 error = VFS_START(mp, 0, curthread); 1317 } 1318 return (error); 1319} 1320 1321/* 1322 * Spin prompting on the console for a suitable root filesystem 1323 */ 1324static int 1325vfs_mountroot_ask(void) 1326{ 1327 char name[128]; 1328 1329 for(;;) { 1330 printf("\nManual root filesystem specification:\n"); 1331 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1332#if defined(__i386__) || defined(__ia64__) 1333 printf(" eg. ufs:da0s1a\n"); 1334#else 1335 printf(" eg. ufs:/dev/da0a\n"); 1336#endif 1337 printf(" ? List valid disk boot devices\n"); 1338 printf(" <empty line> Abort manual input\n"); 1339 printf("\nmountroot> "); 1340 gets(name); 1341 if (name[0] == '\0') 1342 return (1); 1343 if (name[0] == '?') { 1344 printf("\nList of GEOM managed disk devices:\n "); 1345 g_dev_print(); 1346 continue; 1347 } 1348 if (!vfs_mountroot_try(name)) 1349 return (0); 1350 } 1351} 1352 1353/* 1354 * Local helper function for vfs_mountroot_ask. 1355 */ 1356static void 1357gets(char *cp) 1358{ 1359 char *lp; 1360 int c; 1361 1362 lp = cp; 1363 for (;;) { 1364 printf("%c", c = cngetc() & 0177); 1365 switch (c) { 1366 case -1: 1367 case '\n': 1368 case '\r': 1369 *lp++ = '\0'; 1370 return; 1371 case '\b': 1372 case '\177': 1373 if (lp > cp) { 1374 printf(" \b"); 1375 lp--; 1376 } 1377 continue; 1378 case '#': 1379 lp--; 1380 if (lp < cp) 1381 lp = cp; 1382 continue; 1383 case '@': 1384 case 'u' & 037: 1385 lp = cp; 1386 printf("%c", '\n'); 1387 continue; 1388 default: 1389 *lp++ = c; 1390 } 1391 } 1392} 1393 1394/* 1395 * Convert a given name to the cdev pointer of the device, which is probably 1396 * but not by definition, a disk. Mount a DEVFS (on nothing), look the name 1397 * up, extract the cdev from the vnode and unmount it again. Unfortunately 1398 * we cannot use the vnode directly (because we unmount the DEVFS again) 1399 * so the filesystems still have to do the bdevvp() stunt. 1400 */ 1401static struct cdev * 1402getdiskbyname(char *name) 1403{ 1404 char *cp = name; 1405 struct cdev *dev = NULL; 1406 struct thread *td = curthread; 1407 struct vfsconf *vfsp; 1408 struct mount *mp = NULL; 1409 struct vnode *vroot = NULL; 1410 struct nameidata nid; 1411 int error; 1412 1413 if (!bcmp(cp, "/dev/", 5)) 1414 cp += 5; 1415 1416 do { 1417 vfsp = vfs_byname("devfs"); 1418 if (vfsp == NULL) 1419 break; 1420 error = vfs_mount_alloc(NULLVP, vfsp, "/dev", td, &mp); 1421 if (error) 1422 break; 1423 mp->mnt_flag |= MNT_RDONLY; 1424 1425 error = VFS_MOUNT(mp, curthread); 1426 if (error) 1427 break; 1428 VFS_START(mp, 0, td); 1429 VFS_ROOT(mp, &vroot, td); 1430 VOP_UNLOCK(vroot, 0, td); 1431 1432 NDINIT(&nid, LOOKUP, NOCACHE|FOLLOW, 1433 UIO_SYSSPACE, cp, curthread); 1434 nid.ni_startdir = vroot; 1435 nid.ni_pathlen = strlen(cp); 1436 nid.ni_cnd.cn_cred = curthread->td_ucred; 1437 nid.ni_cnd.cn_nameptr = cp; 1438 1439 error = lookup(&nid); 1440 if (error) 1441 break; 1442 if (nid.ni_vp->v_type != VCHR) 1443 dev = NULL; 1444 else 1445 dev = nid.ni_vp->v_rdev; 1446 NDFREE(&nid, 0); 1447 } while (0); 1448 1449 if (vroot != NULL) 1450 VFS_UNMOUNT(mp, 0, td); 1451 if (mp != NULL) 1452 vfs_mount_destroy(mp, td); 1453 return (dev); 1454} 1455 1456/* Show the struct cdev *for a disk specified by name */ 1457#ifdef DDB 1458DB_SHOW_COMMAND(disk, db_getdiskbyname) 1459{ 1460 struct cdev *dev; 1461 1462 if (modif[0] == '\0') { 1463 db_error("usage: show disk/devicename"); 1464 return; 1465 } 1466 dev = getdiskbyname(modif); 1467 if (dev != NULL) 1468 db_printf("struct cdev *= %p\n", dev); 1469 else 1470 db_printf("No disk device matched.\n"); 1471} 1472#endif 1473 1474/* 1475 * Get a mount option by its name. 1476 * 1477 * Return 0 if the option was found, ENOENT otherwise. 1478 * If len is non-NULL it will be filled with the length 1479 * of the option. If buf is non-NULL, it will be filled 1480 * with the address of the option. 1481 */ 1482int 1483vfs_getopt(opts, name, buf, len) 1484 struct vfsoptlist *opts; 1485 const char *name; 1486 void **buf; 1487 int *len; 1488{ 1489 struct vfsopt *opt; 1490 1491 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1492 1493 TAILQ_FOREACH(opt, opts, link) { 1494 if (strcmp(name, opt->name) == 0) { 1495 if (len != NULL) 1496 *len = opt->len; 1497 if (buf != NULL) 1498 *buf = opt->value; 1499 return (0); 1500 } 1501 } 1502 return (ENOENT); 1503} 1504 1505/* 1506 * Find and copy a mount option. 1507 * 1508 * The size of the buffer has to be specified 1509 * in len, if it is not the same length as the 1510 * mount option, EINVAL is returned. 1511 * Returns ENOENT if the option is not found. 1512 */ 1513int 1514vfs_copyopt(opts, name, dest, len) 1515 struct vfsoptlist *opts; 1516 const char *name; 1517 void *dest; 1518 int len; 1519{ 1520 struct vfsopt *opt; 1521 1522 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1523 1524 TAILQ_FOREACH(opt, opts, link) { 1525 if (strcmp(name, opt->name) == 0) { 1526 if (len != opt->len) 1527 return (EINVAL); 1528 bcopy(opt->value, dest, opt->len); 1529 return (0); 1530 } 1531 } 1532 return (ENOENT); 1533} 1534 1535 1536/* 1537 * This is a helper function for filesystems to traverse their 1538 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1539 */ 1540 1541struct vnode * 1542__mnt_vnode_next(struct vnode **nvp, struct mount *mp) 1543{ 1544 struct vnode *vp; 1545 1546 mtx_assert(&mp->mnt_mtx, MA_OWNED); 1547 1548 vp = *nvp; 1549 /* Check if we are done */ 1550 if (vp == NULL) 1551 return (NULL); 1552 /* If our next vnode is no longer ours, start over */ 1553 if (vp->v_mount != mp) 1554 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1555 /* Save pointer to next vnode in list */ 1556 if (vp != NULL) 1557 *nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1558 else 1559 *nvp = NULL; 1560 return (vp); 1561} 1562