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