Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mount.c
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1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 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: releng/5.3/sys/kern/vfs_mount.c 136588 2004-10-16 08:43:07Z cvs2svn $"); 63 64 #include <sys/param.h> 65 #include <sys/conf.h> 66 #include <sys/cons.h> 67 #include <sys/jail.h> 68 #include <sys/kernel.h> 69 #include <sys/linker.h> 70 #include <sys/mac.h> 71 #include <sys/malloc.h> 72 #include <sys/mount.h> 73 #include <sys/mutex.h> 74 #include <sys/namei.h> 75 #include <sys/proc.h> 76 #include <sys/filedesc.h> 77 #include <sys/reboot.h> 78 #include <sys/sysproto.h> 79 #include <sys/sx.h> 80 #include <sys/sysctl.h> 81 #include <sys/sysent.h> 82 #include <sys/systm.h> 83 #include <sys/vnode.h> 84 85 #include <geom/geom.h> 86 87 #include <machine/stdarg.h> 88 89 #include "opt_rootdevname.h" 90 #include "opt_ddb.h" 91 #include "opt_mac.h" 92 93 #ifdef DDB 94 #include <ddb/ddb.h> 95 #endif 96 97 #define ROOTNAME "root_device" 98 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 99 100 static void checkdirs(struct vnode *olddp, struct vnode *newdp); 101 static void gets(char *cp); 102 static int vfs_domount(struct thread *td, const char *fstype, 103 char *fspath, int fsflags, void *fsdata, int compat); 104 static int vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp, 105 const char *fspath, struct thread *td, struct mount **mpp); 106 static int vfs_mountroot_ask(void); 107 static int vfs_mountroot_try(const char *mountfrom); 108 static int vfs_donmount(struct thread *td, int fsflags, 109 struct uio *fsoptions); 110 111 static int usermount = 0; 112 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 113 "Unprivileged users may mount and unmount file systems"); 114 115 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 116 117 /* List of mounted filesystems. */ 118 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 119 120 /* For any iteration/modification of mountlist */ 121 struct mtx mountlist_mtx; 122 123 /* 124 * The vnode of the system's root (/ in the filesystem, without chroot 125 * active.) 126 */ 127 struct 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 */ 143 static char *cdrom_rootdevnames[] = { 144 "cd9660:cd0", 145 "cd9660:acd0", 146 NULL 147 }; 148 149 /* legacy find-root code */ 150 char *rootdevnames[2] = {NULL, NULL}; 151 struct cdev *rootdev = NULL; 152 #ifdef ROOTDEVNAME 153 const char *ctrootdevname = ROOTDEVNAME; 154 #else 155 const 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 */ 163 static int 164 sysctl_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 } 178 179 SYSCTL_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. */ 183 static void 184 vfs_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. */ 200 static void 201 vfs_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 */ 215 static int 216 vfs_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 */ 236 static void 237 vfs_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 */ 258 static int 259 vfs_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 = optlen; 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->value = malloc(optlen, M_MOUNT, M_WAITOK); 312 if (auio->uio_segflg == UIO_SYSSPACE) { 313 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 314 optlen); 315 } else { 316 error = copyin(auio->uio_iov[i + 1].iov_base, 317 opt->value, optlen); 318 if (error) 319 goto bad; 320 } 321 } 322 } 323 vfs_sanitizeopts(opts); 324 *options = opts; 325 return (0); 326 bad: 327 vfs_freeopts(opts); 328 return (error); 329 } 330 331 /* 332 * Merge the old mount options with the new ones passed 333 * in the MNT_UPDATE case. 334 */ 335 static void 336 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 337 { 338 struct vfsopt *opt, *opt2, *new; 339 340 TAILQ_FOREACH(opt, opts, link) { 341 /* 342 * Check that this option hasn't been redefined 343 * nor cancelled with a "no" mount option. 344 */ 345 opt2 = TAILQ_FIRST(toopts); 346 while (opt2 != NULL) { 347 if (strcmp(opt2->name, opt->name) == 0) 348 goto next; 349 if (strncmp(opt2->name, "no", 2) == 0 && 350 strcmp(opt2->name + 2, opt->name) == 0) { 351 vfs_freeopt(toopts, opt2); 352 goto next; 353 } 354 opt2 = TAILQ_NEXT(opt2, link); 355 } 356 /* We want this option, duplicate it. */ 357 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 358 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 359 strcpy(new->name, opt->name); 360 if (opt->len != 0) { 361 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 362 bcopy(opt->value, new->value, opt->len); 363 } else { 364 new->value = NULL; 365 } 366 new->len = opt->len; 367 TAILQ_INSERT_TAIL(toopts, new, link); 368 next: 369 continue; 370 } 371 } 372 373 /* 374 * New mount API. 375 */ 376 int 377 nmount(td, uap) 378 struct thread *td; 379 struct nmount_args /* { 380 struct iovec *iovp; 381 unsigned int iovcnt; 382 int flags; 383 } */ *uap; 384 { 385 struct uio *auio; 386 struct iovec *iov; 387 unsigned int i; 388 int error; 389 u_int iovcnt; 390 391 iovcnt = uap->iovcnt; 392 /* 393 * Check that we have an even number of iovec's 394 * and that we have at least two options. 395 */ 396 if ((iovcnt & 1) || (iovcnt < 4)) 397 return (EINVAL); 398 error = copyinuio(uap->iovp, iovcnt, &auio); 399 if (error) 400 return (error); 401 iov = auio->uio_iov; 402 for (i = 0; i < iovcnt; i++) { 403 if (iov->iov_len > MMAXOPTIONLEN) { 404 free(auio, M_IOV); 405 return (EINVAL); 406 } 407 iov++; 408 } 409 error = vfs_donmount(td, uap->flags, auio); 410 free(auio, M_IOV); 411 return (error); 412 } 413 414 int 415 kernel_mount(struct iovec *iovp, u_int iovcnt, int flags) 416 { 417 struct uio auio; 418 int error; 419 420 /* 421 * Check that we have an even number of iovec's 422 * and that we have at least two options. 423 */ 424 if ((iovcnt & 1) || (iovcnt < 4)) 425 return (EINVAL); 426 427 auio.uio_iov = iovp; 428 auio.uio_iovcnt = iovcnt; 429 auio.uio_segflg = UIO_SYSSPACE; 430 431 error = vfs_donmount(curthread, flags, &auio); 432 return (error); 433 } 434 435 int 436 kernel_vmount(int flags, ...) 437 { 438 struct iovec *iovp; 439 struct uio auio; 440 va_list ap; 441 u_int iovcnt, iovlen, len; 442 const char *cp; 443 char *buf, *pos; 444 size_t n; 445 int error, i; 446 447 len = 0; 448 va_start(ap, flags); 449 for (iovcnt = 0; (cp = va_arg(ap, const char *)) != NULL; iovcnt++) 450 len += strlen(cp) + 1; 451 va_end(ap); 452 453 if (iovcnt < 4 || iovcnt & 1) 454 return (EINVAL); 455 456 iovlen = iovcnt * sizeof (struct iovec); 457 MALLOC(iovp, struct iovec *, iovlen, M_MOUNT, M_WAITOK); 458 MALLOC(buf, char *, len, M_MOUNT, M_WAITOK); 459 pos = buf; 460 va_start(ap, flags); 461 for (i = 0; i < iovcnt; i++) { 462 cp = va_arg(ap, const char *); 463 copystr(cp, pos, len - (pos - buf), &n); 464 iovp[i].iov_base = pos; 465 iovp[i].iov_len = n; 466 pos += n; 467 } 468 va_end(ap); 469 470 auio.uio_iov = iovp; 471 auio.uio_iovcnt = iovcnt; 472 auio.uio_segflg = UIO_SYSSPACE; 473 474 error = vfs_donmount(curthread, flags, &auio); 475 FREE(iovp, M_MOUNT); 476 FREE(buf, M_MOUNT); 477 return (error); 478 } 479 480 /* 481 * Allocate and initialize the mount point struct. 482 */ 483 static int 484 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 485 const char *fspath, struct thread *td, struct mount **mpp) 486 { 487 struct mount *mp; 488 489 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 490 TAILQ_INIT(&mp->mnt_nvnodelist); 491 mp->mnt_nvnodelistsize = 0; 492 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 493 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE); 494 vfs_busy(mp, LK_NOWAIT, 0, td); 495 mp->mnt_op = vfsp->vfc_vfsops; 496 mp->mnt_vfc = vfsp; 497 vfsp->vfc_refcount++; 498 mp->mnt_stat.f_type = vfsp->vfc_typenum; 499 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 500 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 501 mp->mnt_vnodecovered = vp; 502 mp->mnt_cred = crdup(td->td_ucred); 503 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 504 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 505 mp->mnt_iosize_max = DFLTPHYS; 506 #ifdef MAC 507 mac_init_mount(mp); 508 mac_create_mount(td->td_ucred, mp); 509 #endif 510 *mpp = mp; 511 return (0); 512 } 513 514 /* 515 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 516 */ 517 void 518 vfs_mount_destroy(struct mount *mp, struct thread *td) 519 { 520 521 mp->mnt_vfc->vfc_refcount--; 522 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 523 panic("unmount: dangling vnode"); 524 vfs_unbusy(mp,td); 525 lockdestroy(&mp->mnt_lock); 526 mtx_destroy(&mp->mnt_mtx); 527 if (mp->mnt_kern_flag & MNTK_MWAIT) 528 wakeup(mp); 529 #ifdef MAC 530 mac_destroy_mount(mp); 531 #endif 532 if (mp->mnt_opt != NULL) 533 vfs_freeopts(mp->mnt_opt); 534 crfree(mp->mnt_cred); 535 free(mp, M_MOUNT); 536 } 537 538 static int 539 vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 540 { 541 struct vfsoptlist *optlist; 542 char *fstype, *fspath; 543 int error, fstypelen, fspathlen; 544 545 error = vfs_buildopts(fsoptions, &optlist); 546 if (error) 547 return (error); 548 549 /* 550 * We need these two options before the others, 551 * and they are mandatory for any filesystem. 552 * Ensure they are NUL terminated as well. 553 */ 554 fstypelen = 0; 555 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 556 if (error || fstype[fstypelen - 1] != '\0') { 557 error = EINVAL; 558 goto bail; 559 } 560 fspathlen = 0; 561 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 562 if (error || fspath[fspathlen - 1] != '\0') { 563 error = EINVAL; 564 goto bail; 565 } 566 567 /* 568 * Be ultra-paranoid about making sure the type and fspath 569 * variables will fit in our mp buffers, including the 570 * terminating NUL. 571 */ 572 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 573 error = ENAMETOOLONG; 574 goto bail; 575 } 576 577 error = vfs_domount(td, fstype, fspath, fsflags, optlist, 0); 578 bail: 579 if (error) 580 vfs_freeopts(optlist); 581 return (error); 582 } 583 584 /* 585 * Old mount API. 586 */ 587 #ifndef _SYS_SYSPROTO_H_ 588 struct mount_args { 589 char *type; 590 char *path; 591 int flags; 592 caddr_t data; 593 }; 594 #endif 595 /* ARGSUSED */ 596 int 597 mount(td, uap) 598 struct thread *td; 599 struct mount_args /* { 600 char *type; 601 char *path; 602 int flags; 603 caddr_t data; 604 } */ *uap; 605 { 606 char *fstype; 607 char *fspath; 608 int error; 609 610 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 611 fspath = malloc(MNAMELEN, M_TEMP, M_WAITOK); 612 613 /* 614 * vfs_mount() actually takes a kernel string for `type' and 615 * `path' now, so extract them. 616 */ 617 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 618 if (error == 0) 619 error = copyinstr(uap->path, fspath, MNAMELEN, NULL); 620 if (error == 0) 621 error = vfs_domount(td, fstype, fspath, uap->flags, 622 uap->data, 1); 623 free(fstype, M_TEMP); 624 free(fspath, M_TEMP); 625 return (error); 626 } 627 628 /* 629 * vfs_mount(): actually attempt a filesystem mount. 630 * 631 * This routine is designed to be a "generic" entry point for routines 632 * that wish to mount a filesystem. All parameters except `fsdata' are 633 * pointers into kernel space. `fsdata' is currently still a pointer 634 * into userspace. 635 */ 636 int 637 vfs_mount(td, fstype, fspath, fsflags, fsdata) 638 struct thread *td; 639 const char *fstype; 640 char *fspath; 641 int fsflags; 642 void *fsdata; 643 { 644 645 return (vfs_domount(td, fstype, fspath, fsflags, fsdata, 1)); 646 } 647 648 /* 649 * vfs_domount(): actually attempt a filesystem mount. 650 */ 651 static int 652 vfs_domount( 653 struct thread *td, /* Flags common to all filesystems. */ 654 const char *fstype, /* Filesystem type. */ 655 char *fspath, /* Mount path. */ 656 int fsflags, /* Flags common to all filesystems. */ 657 void *fsdata, /* Options local to the filesystem. */ 658 int compat /* Invocation from compat syscall. */ 659 ) 660 { 661 linker_file_t lf; 662 struct vnode *vp; 663 struct mount *mp; 664 struct vfsconf *vfsp; 665 int error, flag = 0, kern_flag = 0; 666 struct vattr va; 667 struct nameidata nd; 668 669 /* 670 * Be ultra-paranoid about making sure the type and fspath 671 * variables will fit in our mp buffers, including the 672 * terminating NUL. 673 */ 674 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 675 return (ENAMETOOLONG); 676 677 if (jailed(td->td_ucred)) 678 return (EPERM); 679 if (usermount == 0) { 680 if ((error = suser(td)) != 0) 681 return (error); 682 } 683 684 /* 685 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 686 */ 687 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 688 if ((error = suser(td)) != 0) 689 return (error); 690 } 691 /* 692 * Silently enforce MNT_NODEV, MNT_NOSUID and MNT_USER for 693 * unprivileged users. 694 */ 695 if (suser(td) != 0) 696 fsflags |= MNT_NODEV | MNT_NOSUID | MNT_USER; 697 /* 698 * Get vnode to be covered 699 */ 700 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 701 if ((error = namei(&nd)) != 0) 702 return (error); 703 NDFREE(&nd, NDF_ONLY_PNBUF); 704 vp = nd.ni_vp; 705 if (fsflags & MNT_UPDATE) { 706 if ((vp->v_vflag & VV_ROOT) == 0) { 707 vput(vp); 708 return (EINVAL); 709 } 710 mp = vp->v_mount; 711 flag = mp->mnt_flag; 712 kern_flag = mp->mnt_kern_flag; 713 /* 714 * We only allow the filesystem to be reloaded if it 715 * is currently mounted read-only. 716 */ 717 if ((fsflags & MNT_RELOAD) && 718 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 719 vput(vp); 720 return (EOPNOTSUPP); /* Needs translation */ 721 } 722 /* 723 * Only privileged root, or (if MNT_USER is set) the user that 724 * did the original mount is permitted to update it. 725 */ 726 error = vfs_suser(mp, td); 727 if (error) { 728 vput(vp); 729 return (error); 730 } 731 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 732 vput(vp); 733 return (EBUSY); 734 } 735 VI_LOCK(vp); 736 if ((vp->v_iflag & VI_MOUNT) != 0 || 737 vp->v_mountedhere != NULL) { 738 VI_UNLOCK(vp); 739 vfs_unbusy(mp, td); 740 vput(vp); 741 return (EBUSY); 742 } 743 vp->v_iflag |= VI_MOUNT; 744 VI_UNLOCK(vp); 745 mp->mnt_flag |= fsflags & 746 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT); 747 VOP_UNLOCK(vp, 0, td); 748 if (compat == 0) { 749 mp->mnt_optnew = fsdata; 750 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 751 } 752 } else { 753 /* 754 * If the user is not root, ensure that they own the directory 755 * onto which we are attempting to mount. 756 */ 757 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 758 if (error) { 759 vput(vp); 760 return (error); 761 } 762 if (va.va_uid != td->td_ucred->cr_uid) { 763 if ((error = suser(td)) != 0) { 764 vput(vp); 765 return (error); 766 } 767 } 768 if ((error = vinvalbuf(vp, V_SAVE, td->td_ucred, td, 0, 0)) != 0) { 769 vput(vp); 770 return (error); 771 } 772 if (vp->v_type != VDIR) { 773 vput(vp); 774 return (ENOTDIR); 775 } 776 vfsp = vfs_byname(fstype); 777 if (vfsp == NULL) { 778 /* Only load modules for root (very important!). */ 779 if ((error = suser(td)) != 0) { 780 vput(vp); 781 return (error); 782 } 783 error = securelevel_gt(td->td_ucred, 0); 784 if (error) { 785 vput(vp); 786 return (error); 787 } 788 error = linker_load_module(NULL, fstype, NULL, NULL, &lf); 789 if (error || lf == NULL) { 790 vput(vp); 791 if (lf == NULL) 792 error = ENODEV; 793 return (error); 794 } 795 lf->userrefs++; 796 /* Look up again to see if the VFS was loaded. */ 797 vfsp = vfs_byname(fstype); 798 if (vfsp == NULL) { 799 lf->userrefs--; 800 linker_file_unload(lf, LINKER_UNLOAD_FORCE); 801 vput(vp); 802 return (ENODEV); 803 } 804 } 805 VI_LOCK(vp); 806 if ((vp->v_iflag & VI_MOUNT) != 0 || 807 vp->v_mountedhere != NULL) { 808 VI_UNLOCK(vp); 809 vput(vp); 810 return (EBUSY); 811 } 812 vp->v_iflag |= VI_MOUNT; 813 VI_UNLOCK(vp); 814 815 /* 816 * Allocate and initialize the filesystem. 817 */ 818 error = vfs_mount_alloc(vp, vfsp, fspath, td, &mp); 819 if (error) { 820 vput(vp); 821 return (error); 822 } 823 VOP_UNLOCK(vp, 0, td); 824 825 /* XXXMAC: pass to vfs_mount_alloc? */ 826 if (compat == 0) 827 mp->mnt_optnew = fsdata; 828 } 829 /* 830 * Check if the fs implements the type VFS_[O]MOUNT() 831 * function we are looking for. 832 */ 833 if ((compat == 0) == (mp->mnt_op->vfs_omount != NULL)) { 834 printf("%s doesn't support the %s mount syscall\n", 835 mp->mnt_vfc->vfc_name, compat ? "old" : "new"); 836 VI_LOCK(vp); 837 vp->v_iflag &= ~VI_MOUNT; 838 VI_UNLOCK(vp); 839 if (mp->mnt_flag & MNT_UPDATE) 840 vfs_unbusy(mp, td); 841 else 842 vfs_mount_destroy(mp, td); 843 vrele(vp); 844 return (EOPNOTSUPP); 845 } 846 847 /* 848 * Set the mount level flags. 849 */ 850 if (fsflags & MNT_RDONLY) 851 mp->mnt_flag |= MNT_RDONLY; 852 else if (mp->mnt_flag & MNT_RDONLY) 853 mp->mnt_kern_flag |= MNTK_WANTRDWR; 854 mp->mnt_flag &=~ MNT_UPDATEMASK; 855 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE); 856 /* 857 * Mount the filesystem. 858 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 859 * get. No freeing of cn_pnbuf. 860 */ 861 if (compat) 862 error = VFS_OMOUNT(mp, fspath, fsdata, td); 863 else 864 error = VFS_MOUNT(mp, td); 865 if (!error) { 866 if (mp->mnt_opt != NULL) 867 vfs_freeopts(mp->mnt_opt); 868 mp->mnt_opt = mp->mnt_optnew; 869 } 870 /* 871 * Prevent external consumers of mount options from reading 872 * mnt_optnew. 873 */ 874 mp->mnt_optnew = NULL; 875 if (mp->mnt_flag & MNT_UPDATE) { 876 if (mp->mnt_kern_flag & MNTK_WANTRDWR) 877 mp->mnt_flag &= ~MNT_RDONLY; 878 mp->mnt_flag &= 879 ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 880 mp->mnt_kern_flag &= ~MNTK_WANTRDWR; 881 if (error) { 882 mp->mnt_flag = flag; 883 mp->mnt_kern_flag = kern_flag; 884 } 885 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 886 if (mp->mnt_syncer == NULL) 887 error = vfs_allocate_syncvnode(mp); 888 } else { 889 if (mp->mnt_syncer != NULL) 890 vrele(mp->mnt_syncer); 891 mp->mnt_syncer = NULL; 892 } 893 vfs_unbusy(mp, td); 894 VI_LOCK(vp); 895 vp->v_iflag &= ~VI_MOUNT; 896 VI_UNLOCK(vp); 897 vrele(vp); 898 return (error); 899 } 900 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 901 /* 902 * Put the new filesystem on the mount list after root. 903 */ 904 cache_purge(vp); 905 if (!error) { 906 struct vnode *newdp; 907 908 VI_LOCK(vp); 909 vp->v_iflag &= ~VI_MOUNT; 910 VI_UNLOCK(vp); 911 vp->v_mountedhere = mp; 912 mtx_lock(&mountlist_mtx); 913 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 914 mtx_unlock(&mountlist_mtx); 915 vfs_event_signal(NULL, VQ_MOUNT, 0); 916 if (VFS_ROOT(mp, &newdp, td)) 917 panic("mount: lost mount"); 918 checkdirs(vp, newdp); 919 vput(newdp); 920 VOP_UNLOCK(vp, 0, td); 921 if ((mp->mnt_flag & MNT_RDONLY) == 0) 922 error = vfs_allocate_syncvnode(mp); 923 vfs_unbusy(mp, td); 924 if (error || (error = VFS_START(mp, 0, td)) != 0) 925 vrele(vp); 926 } else { 927 VI_LOCK(vp); 928 vp->v_iflag &= ~VI_MOUNT; 929 VI_UNLOCK(vp); 930 vfs_mount_destroy(mp, td); 931 vput(vp); 932 } 933 return (error); 934 } 935 936 /* 937 * Scan all active processes to see if any of them have a current 938 * or root directory of `olddp'. If so, replace them with the new 939 * mount point. 940 */ 941 static void 942 checkdirs(olddp, newdp) 943 struct vnode *olddp, *newdp; 944 { 945 struct filedesc *fdp; 946 struct proc *p; 947 int nrele; 948 949 if (vrefcnt(olddp) == 1) 950 return; 951 sx_slock(&allproc_lock); 952 LIST_FOREACH(p, &allproc, p_list) { 953 mtx_lock(&fdesc_mtx); 954 fdp = p->p_fd; 955 if (fdp == NULL) { 956 mtx_unlock(&fdesc_mtx); 957 continue; 958 } 959 nrele = 0; 960 FILEDESC_LOCK(fdp); 961 if (fdp->fd_cdir == olddp) { 962 VREF(newdp); 963 fdp->fd_cdir = newdp; 964 nrele++; 965 } 966 if (fdp->fd_rdir == olddp) { 967 VREF(newdp); 968 fdp->fd_rdir = newdp; 969 nrele++; 970 } 971 FILEDESC_UNLOCK(fdp); 972 mtx_unlock(&fdesc_mtx); 973 while (nrele--) 974 vrele(olddp); 975 } 976 sx_sunlock(&allproc_lock); 977 if (rootvnode == olddp) { 978 vrele(rootvnode); 979 VREF(newdp); 980 rootvnode = newdp; 981 } 982 } 983 984 /* 985 * Unmount a filesystem. 986 * 987 * Note: unmount takes a path to the vnode mounted on as argument, 988 * not special file (as before). 989 */ 990 #ifndef _SYS_SYSPROTO_H_ 991 struct unmount_args { 992 char *path; 993 int flags; 994 }; 995 #endif 996 /* ARGSUSED */ 997 int 998 unmount(td, uap) 999 struct thread *td; 1000 register struct unmount_args /* { 1001 char *path; 1002 int flags; 1003 } */ *uap; 1004 { 1005 struct mount *mp; 1006 char *pathbuf; 1007 int error, id0, id1; 1008 1009 if (jailed(td->td_ucred)) 1010 return (EPERM); 1011 if (usermount == 0) { 1012 if ((error = suser(td)) != 0) 1013 return (error); 1014 } 1015 1016 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1017 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1018 if (error) { 1019 free(pathbuf, M_TEMP); 1020 return (error); 1021 } 1022 if (uap->flags & MNT_BYFSID) { 1023 /* Decode the filesystem ID. */ 1024 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1025 free(pathbuf, M_TEMP); 1026 return (EINVAL); 1027 } 1028 1029 mtx_lock(&mountlist_mtx); 1030 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1031 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1032 mp->mnt_stat.f_fsid.val[1] == id1) 1033 break; 1034 } 1035 mtx_unlock(&mountlist_mtx); 1036 } else { 1037 mtx_lock(&mountlist_mtx); 1038 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1039 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1040 break; 1041 } 1042 mtx_unlock(&mountlist_mtx); 1043 } 1044 free(pathbuf, M_TEMP); 1045 if (mp == NULL) { 1046 /* 1047 * Previously we returned ENOENT for a nonexistent path and 1048 * EINVAL for a non-mountpoint. We cannot tell these apart 1049 * now, so in the !MNT_BYFSID case return the more likely 1050 * EINVAL for compatibility. 1051 */ 1052 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1053 } 1054 1055 /* 1056 * Only privileged root, or (if MNT_USER is set) the user that did the 1057 * original mount is permitted to unmount this filesystem. 1058 */ 1059 error = vfs_suser(mp, td); 1060 if (error) 1061 return (error); 1062 1063 /* 1064 * Don't allow unmounting the root filesystem. 1065 */ 1066 if (mp->mnt_flag & MNT_ROOTFS) 1067 return (EINVAL); 1068 return (dounmount(mp, uap->flags, td)); 1069 } 1070 1071 /* 1072 * Do the actual filesystem unmount. 1073 */ 1074 int 1075 dounmount(mp, flags, td) 1076 struct mount *mp; 1077 int flags; 1078 struct thread *td; 1079 { 1080 struct vnode *coveredvp, *fsrootvp; 1081 int error; 1082 int async_flag; 1083 1084 mtx_lock(&mountlist_mtx); 1085 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1086 mtx_unlock(&mountlist_mtx); 1087 return (EBUSY); 1088 } 1089 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1090 /* Allow filesystems to detect that a forced unmount is in progress. */ 1091 if (flags & MNT_FORCE) 1092 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1093 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1094 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), &mountlist_mtx, td); 1095 if (error) { 1096 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1097 if (mp->mnt_kern_flag & MNTK_MWAIT) 1098 wakeup(mp); 1099 return (error); 1100 } 1101 vn_start_write(NULL, &mp, V_WAIT); 1102 1103 if (mp->mnt_flag & MNT_EXPUBLIC) 1104 vfs_setpublicfs(NULL, NULL, NULL); 1105 1106 vfs_msync(mp, MNT_WAIT); 1107 async_flag = mp->mnt_flag & MNT_ASYNC; 1108 mp->mnt_flag &= ~MNT_ASYNC; 1109 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1110 if (mp->mnt_syncer != NULL) 1111 vrele(mp->mnt_syncer); 1112 /* 1113 * For forced unmounts, move process cdir/rdir refs on the fs root 1114 * vnode to the covered vnode. For non-forced unmounts we want 1115 * such references to cause an EBUSY error. 1116 */ 1117 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1118 if (mp->mnt_vnodecovered != NULL) 1119 checkdirs(fsrootvp, mp->mnt_vnodecovered); 1120 if (fsrootvp == rootvnode) { 1121 vrele(rootvnode); 1122 rootvnode = NULL; 1123 } 1124 vput(fsrootvp); 1125 } 1126 if (((mp->mnt_flag & MNT_RDONLY) || 1127 (error = VFS_SYNC(mp, MNT_WAIT, td->td_ucred, td)) == 0) || 1128 (flags & MNT_FORCE)) { 1129 error = VFS_UNMOUNT(mp, flags, td); 1130 } 1131 vn_finished_write(mp); 1132 if (error) { 1133 /* Undo cdir/rdir and rootvnode changes made above. */ 1134 if ((flags & MNT_FORCE) && VFS_ROOT(mp, &fsrootvp, td) == 0) { 1135 if (mp->mnt_vnodecovered != NULL) 1136 checkdirs(mp->mnt_vnodecovered, fsrootvp); 1137 if (rootvnode == NULL) { 1138 rootvnode = fsrootvp; 1139 vref(rootvnode); 1140 } 1141 vput(fsrootvp); 1142 } 1143 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1144 (void) vfs_allocate_syncvnode(mp); 1145 mtx_lock(&mountlist_mtx); 1146 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1147 mp->mnt_flag |= async_flag; 1148 lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, 1149 &mountlist_mtx, td); 1150 if (mp->mnt_kern_flag & MNTK_MWAIT) 1151 wakeup(mp); 1152 return (error); 1153 } 1154 mtx_lock(&mountlist_mtx); 1155 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1156 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 1157 coveredvp->v_mountedhere = NULL; 1158 mtx_unlock(&mountlist_mtx); 1159 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1160 vfs_mount_destroy(mp, td); 1161 if (coveredvp != NULL) 1162 vrele(coveredvp); 1163 return (0); 1164 } 1165 1166 /* 1167 * Lookup a filesystem type, and if found allocate and initialize 1168 * a mount structure for it. 1169 * 1170 * Devname is usually updated by mount(8) after booting. 1171 */ 1172 int 1173 vfs_rootmountalloc(fstypename, devname, mpp) 1174 char *fstypename; 1175 char *devname; 1176 struct mount **mpp; 1177 { 1178 struct thread *td = curthread; /* XXX */ 1179 struct vfsconf *vfsp; 1180 struct mount *mp; 1181 int error; 1182 1183 if (fstypename == NULL) 1184 return (ENODEV); 1185 vfsp = vfs_byname(fstypename); 1186 if (vfsp == NULL) 1187 return (ENODEV); 1188 error = vfs_mount_alloc(NULLVP, vfsp, "/", td, &mp); 1189 if (error) 1190 return (error); 1191 mp->mnt_flag |= MNT_RDONLY | MNT_ROOTFS; 1192 strlcpy(mp->mnt_stat.f_mntfromname, devname, MNAMELEN); 1193 *mpp = mp; 1194 return (0); 1195 } 1196 1197 /* 1198 * Find and mount the root filesystem 1199 */ 1200 void 1201 vfs_mountroot(void) 1202 { 1203 char *cp; 1204 int error, i, asked = 0; 1205 1206 1207 /* 1208 * Wait for GEOM to settle down 1209 */ 1210 g_waitidle(); 1211 1212 /* 1213 * We are booted with instructions to prompt for the root filesystem. 1214 */ 1215 if (boothowto & RB_ASKNAME) { 1216 if (!vfs_mountroot_ask()) 1217 return; 1218 asked = 1; 1219 } 1220 1221 /* 1222 * The root filesystem information is compiled in, and we are 1223 * booted with instructions to use it. 1224 */ 1225 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1226 if (!vfs_mountroot_try(ctrootdevname)) 1227 return; 1228 ctrootdevname = NULL; 1229 } 1230 1231 /* 1232 * We've been given the generic "use CDROM as root" flag. This is 1233 * necessary because one media may be used in many different 1234 * devices, so we need to search for them. 1235 */ 1236 if (boothowto & RB_CDROM) { 1237 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1238 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1239 return; 1240 } 1241 } 1242 1243 /* 1244 * Try to use the value read by the loader from /etc/fstab, or 1245 * supplied via some other means. This is the preferred 1246 * mechanism. 1247 */ 1248 cp = getenv("vfs.root.mountfrom"); 1249 if (cp != NULL) { 1250 error = vfs_mountroot_try(cp); 1251 freeenv(cp); 1252 if (!error) 1253 return; 1254 } 1255 1256 /* 1257 * Try values that may have been computed by code during boot 1258 */ 1259 if (!vfs_mountroot_try(rootdevnames[0])) 1260 return; 1261 if (!vfs_mountroot_try(rootdevnames[1])) 1262 return; 1263 1264 /* 1265 * If we (still) have a compiled-in default, try it. 1266 */ 1267 if (ctrootdevname != NULL) 1268 if (!vfs_mountroot_try(ctrootdevname)) 1269 return; 1270 1271 /* 1272 * Everything so far has failed, prompt on the console if we haven't 1273 * already tried that. 1274 */ 1275 if (!asked) 1276 if (!vfs_mountroot_ask()) 1277 return; 1278 panic("Root mount failed, startup aborted."); 1279 } 1280 1281 /* 1282 * Mount (mountfrom) as the root filesystem. 1283 */ 1284 static int 1285 vfs_mountroot_try(const char *mountfrom) 1286 { 1287 struct mount *mp; 1288 char *vfsname, *path; 1289 const char *devname; 1290 int error; 1291 char patt[32]; 1292 int s; 1293 1294 vfsname = NULL; 1295 path = NULL; 1296 mp = NULL; 1297 error = EINVAL; 1298 1299 if (mountfrom == NULL) 1300 return (error); /* don't complain */ 1301 1302 s = splcam(); /* Overkill, but annoying without it */ 1303 printf("Mounting root from %s\n", mountfrom); 1304 splx(s); 1305 1306 /* parse vfs name and path */ 1307 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1308 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1309 vfsname[0] = path[0] = 0; 1310 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1311 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1312 goto done; 1313 1314 /* allocate a root mount */ 1315 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 1316 &mp); 1317 if (error != 0) { 1318 printf("Can't allocate root mount for filesystem '%s': %d\n", 1319 vfsname, error); 1320 goto done; 1321 } 1322 1323 /* 1324 * do our best to set rootdev 1325 * XXX: This does not belong here! 1326 */ 1327 if (path[0] != '\0') { 1328 struct cdev *diskdev; 1329 diskdev = getdiskbyname(path); 1330 if (diskdev != NULL) 1331 rootdev = diskdev; 1332 else 1333 printf("setrootbyname failed\n"); 1334 } 1335 1336 /* If the root device is a type "memory disk", mount RW */ 1337 if (rootdev != NULL && devsw(rootdev) != NULL) { 1338 devname = devtoname(rootdev); 1339 if (devname[0] == 'm' && devname[1] == 'd') 1340 mp->mnt_flag &= ~MNT_RDONLY; 1341 } 1342 1343 error = VFS_OMOUNT(mp, NULL, NULL, curthread); 1344 1345 done: 1346 if (vfsname != NULL) 1347 free(vfsname, M_MOUNT); 1348 if (path != NULL) 1349 free(path, M_MOUNT); 1350 if (error != 0) { 1351 if (mp != NULL) 1352 vfs_mount_destroy(mp, curthread); 1353 printf("Root mount failed: %d\n", error); 1354 } else { 1355 1356 /* register with list of mounted filesystems */ 1357 mtx_lock(&mountlist_mtx); 1358 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1359 mtx_unlock(&mountlist_mtx); 1360 1361 /* sanity check system clock against root fs timestamp */ 1362 inittodr(mp->mnt_time); 1363 vfs_unbusy(mp, curthread); 1364 error = VFS_START(mp, 0, curthread); 1365 } 1366 return (error); 1367 } 1368 1369 /* 1370 * Spin prompting on the console for a suitable root filesystem 1371 */ 1372 static int 1373 vfs_mountroot_ask(void) 1374 { 1375 char name[128]; 1376 1377 for(;;) { 1378 printf("\nManual root filesystem specification:\n"); 1379 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1380 #if defined(__i386__) || defined(__ia64__) 1381 printf(" eg. ufs:da0s1a\n"); 1382 #else 1383 printf(" eg. ufs:/dev/da0a\n"); 1384 #endif 1385 printf(" ? List valid disk boot devices\n"); 1386 printf(" <empty line> Abort manual input\n"); 1387 printf("\nmountroot> "); 1388 gets(name); 1389 if (name[0] == '\0') 1390 return (1); 1391 if (name[0] == '?') { 1392 printf("\nList of GEOM managed disk devices:\n "); 1393 g_dev_print(); 1394 continue; 1395 } 1396 if (!vfs_mountroot_try(name)) 1397 return (0); 1398 } 1399 } 1400 1401 /* 1402 * Local helper function for vfs_mountroot_ask. 1403 */ 1404 static void 1405 gets(char *cp) 1406 { 1407 char *lp; 1408 int c; 1409 1410 lp = cp; 1411 for (;;) { 1412 printf("%c", c = cngetc() & 0177); 1413 switch (c) { 1414 case -1: 1415 case '\n': 1416 case '\r': 1417 *lp++ = '\0'; 1418 return; 1419 case '\b': 1420 case '\177': 1421 if (lp > cp) { 1422 printf(" \b"); 1423 lp--; 1424 } 1425 continue; 1426 case '#': 1427 lp--; 1428 if (lp < cp) 1429 lp = cp; 1430 continue; 1431 case '@': 1432 case 'u' & 037: 1433 lp = cp; 1434 printf("%c", '\n'); 1435 continue; 1436 default: 1437 *lp++ = c; 1438 } 1439 } 1440 } 1441 1442 /* 1443 * Convert a given name to the cdev pointer of the device, which is probably 1444 * but not by definition, a disk. Mount a DEVFS (on nothing), look the name 1445 * up, extract the cdev from the vnode and unmount it again. Unfortunately 1446 * we cannot use the vnode directly (because we unmount the DEVFS again) 1447 * so the filesystems still have to do the bdevvp() stunt. 1448 */ 1449 struct cdev * 1450 getdiskbyname(char *name) 1451 { 1452 char *cp = name; 1453 struct cdev *dev = NULL; 1454 struct thread *td = curthread; 1455 struct vfsconf *vfsp; 1456 struct mount *mp = NULL; 1457 struct vnode *vroot = NULL; 1458 struct nameidata nid; 1459 int error; 1460 1461 if (!bcmp(cp, "/dev/", 5)) 1462 cp += 5; 1463 1464 do { 1465 vfsp = vfs_byname("devfs"); 1466 if (vfsp == NULL) 1467 break; 1468 error = vfs_mount_alloc(NULLVP, vfsp, "/dev", td, &mp); 1469 if (error) 1470 break; 1471 mp->mnt_flag |= MNT_RDONLY; 1472 1473 error = VFS_MOUNT(mp, curthread); 1474 if (error) 1475 break; 1476 VFS_START(mp, 0, td); 1477 VFS_ROOT(mp, &vroot, td); 1478 VOP_UNLOCK(vroot, 0, td); 1479 1480 NDINIT(&nid, LOOKUP, NOCACHE|FOLLOW, 1481 UIO_SYSSPACE, cp, curthread); 1482 nid.ni_startdir = vroot; 1483 nid.ni_pathlen = strlen(cp); 1484 nid.ni_cnd.cn_cred = curthread->td_ucred; 1485 nid.ni_cnd.cn_nameptr = cp; 1486 1487 error = lookup(&nid); 1488 if (error) 1489 break; 1490 dev = vn_todev (nid.ni_vp); 1491 NDFREE(&nid, 0); 1492 } while (0); 1493 1494 if (vroot != NULL) 1495 VFS_UNMOUNT(mp, 0, td); 1496 if (mp != NULL) 1497 vfs_mount_destroy(mp, td); 1498 return (dev); 1499 } 1500 1501 /* Show the struct cdev *for a disk specified by name */ 1502 #ifdef DDB 1503 DB_SHOW_COMMAND(disk, db_getdiskbyname) 1504 { 1505 struct cdev *dev; 1506 1507 if (modif[0] == '\0') { 1508 db_error("usage: show disk/devicename"); 1509 return; 1510 } 1511 dev = getdiskbyname(modif); 1512 if (dev != NULL) 1513 db_printf("struct cdev *= %p\n", dev); 1514 else 1515 db_printf("No disk device matched.\n"); 1516 } 1517 #endif 1518 1519 /* 1520 * Get a mount option by its name. 1521 * 1522 * Return 0 if the option was found, ENOENT otherwise. 1523 * If len is non-NULL it will be filled with the length 1524 * of the option. If buf is non-NULL, it will be filled 1525 * with the address of the option. 1526 */ 1527 int 1528 vfs_getopt(opts, name, buf, len) 1529 struct vfsoptlist *opts; 1530 const char *name; 1531 void **buf; 1532 int *len; 1533 { 1534 struct vfsopt *opt; 1535 1536 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1537 1538 TAILQ_FOREACH(opt, opts, link) { 1539 if (strcmp(name, opt->name) == 0) { 1540 if (len != NULL) 1541 *len = opt->len; 1542 if (buf != NULL) 1543 *buf = opt->value; 1544 return (0); 1545 } 1546 } 1547 return (ENOENT); 1548 } 1549 1550 /* 1551 * Find and copy a mount option. 1552 * 1553 * The size of the buffer has to be specified 1554 * in len, if it is not the same length as the 1555 * mount option, EINVAL is returned. 1556 * Returns ENOENT if the option is not found. 1557 */ 1558 int 1559 vfs_copyopt(opts, name, dest, len) 1560 struct vfsoptlist *opts; 1561 const char *name; 1562 void *dest; 1563 int len; 1564 { 1565 struct vfsopt *opt; 1566 1567 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1568 1569 TAILQ_FOREACH(opt, opts, link) { 1570 if (strcmp(name, opt->name) == 0) { 1571 if (len != opt->len) 1572 return (EINVAL); 1573 bcopy(opt->value, dest, opt->len); 1574 return (0); 1575 } 1576 } 1577 return (ENOENT); 1578 } 1579 1580 1581 /* 1582 * This is a helper function for filesystems to traverse their 1583 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1584 */ 1585 1586 struct vnode * 1587 __mnt_vnode_next(struct vnode **nvp, struct mount *mp) 1588 { 1589 struct vnode *vp; 1590 1591 mtx_assert(&mp->mnt_mtx, MA_OWNED); 1592 vp = *nvp; 1593 /* Check if we are done */ 1594 if (vp == NULL) 1595 return (NULL); 1596 /* If our next vnode is no longer ours, start over */ 1597 if (vp->v_mount != mp) 1598 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1599 /* Save pointer to next vnode in list */ 1600 if (vp != NULL) 1601 *nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1602 else 1603 *nvp = NULL; 1604 return (vp); 1605 }
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