Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mount.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
1 /*- 2 * Copyright (c) 1999-2004 Poul-Henning Kamp 3 * Copyright (c) 1999 Michael Smith 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/6.0/sys/kern/vfs_mount.c 150744 2005-09-30 06:10:59Z delphij $"); 39 40 #include <sys/param.h> 41 #include <sys/conf.h> 42 #include <sys/jail.h> 43 #include <sys/kernel.h> 44 #include <sys/libkern.h> 45 #include <sys/mac.h> 46 #include <sys/malloc.h> 47 #include <sys/mount.h> 48 #include <sys/mutex.h> 49 #include <sys/namei.h> 50 #include <sys/proc.h> 51 #include <sys/filedesc.h> 52 #include <sys/reboot.h> 53 #include <sys/syscallsubr.h> 54 #include <sys/sysproto.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 61 #include <geom/geom.h> 62 63 #include <machine/stdarg.h> 64 65 #include "opt_rootdevname.h" 66 #include "opt_ddb.h" 67 #include "opt_mac.h" 68 69 #ifdef DDB 70 #include <ddb/ddb.h> 71 #endif 72 73 #define ROOTNAME "root_device" 74 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 75 76 static int vfs_domount(struct thread *td, const char *fstype, 77 char *fspath, int fsflags, void *fsdata); 78 static int vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp, 79 const char *fspath, struct thread *td, struct mount **mpp); 80 static int vfs_mountroot_ask(void); 81 static int vfs_mountroot_try(const char *mountfrom); 82 static int vfs_donmount(struct thread *td, int fsflags, 83 struct uio *fsoptions); 84 static void free_mntarg(struct mntarg *ma); 85 static void vfs_mount_destroy(struct mount *, struct thread *); 86 87 static int usermount = 0; 88 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 89 "Unprivileged users may mount and unmount file systems"); 90 91 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 92 93 /* List of mounted filesystems. */ 94 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 95 96 /* For any iteration/modification of mountlist */ 97 struct mtx mountlist_mtx; 98 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 99 100 TAILQ_HEAD(vfsoptlist, vfsopt); 101 struct vfsopt { 102 TAILQ_ENTRY(vfsopt) link; 103 char *name; 104 void *value; 105 int len; 106 }; 107 108 /* 109 * The vnode of the system's root (/ in the filesystem, without chroot 110 * active.) 111 */ 112 struct vnode *rootvnode; 113 114 /* 115 * The root filesystem is detailed in the kernel environment variable 116 * vfs.root.mountfrom, which is expected to be in the general format 117 * 118 * <vfsname>:[<path>] 119 * vfsname := the name of a VFS known to the kernel and capable 120 * of being mounted as root 121 * path := disk device name or other data used by the filesystem 122 * to locate its physical store 123 */ 124 125 /* 126 * Global opts, taken by all filesystems 127 */ 128 static const char *global_opts[] = { 129 "fstype", 130 "fspath", 131 "ro", 132 "suid", 133 "exec", 134 NULL 135 }; 136 137 /* 138 * The root specifiers we will try if RB_CDROM is specified. 139 */ 140 static char *cdrom_rootdevnames[] = { 141 "cd9660:cd0", 142 "cd9660:acd0", 143 NULL 144 }; 145 146 /* legacy find-root code */ 147 char *rootdevnames[2] = {NULL, NULL}; 148 #ifndef ROOTDEVNAME 149 # define ROOTDEVNAME NULL 150 #endif 151 static const char *ctrootdevname = ROOTDEVNAME; 152 153 /* 154 * --------------------------------------------------------------------- 155 * Functions for building and sanitizing the mount options 156 */ 157 158 /* Remove one mount option. */ 159 static void 160 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 161 { 162 163 TAILQ_REMOVE(opts, opt, link); 164 free(opt->name, M_MOUNT); 165 if (opt->value != NULL) 166 free(opt->value, M_MOUNT); 167 #ifdef INVARIANTS 168 else if (opt->len != 0) 169 panic("%s: mount option with NULL value but length != 0", 170 __func__); 171 #endif 172 free(opt, M_MOUNT); 173 } 174 175 /* Release all resources related to the mount options. */ 176 static void 177 vfs_freeopts(struct vfsoptlist *opts) 178 { 179 struct vfsopt *opt; 180 181 while (!TAILQ_EMPTY(opts)) { 182 opt = TAILQ_FIRST(opts); 183 vfs_freeopt(opts, opt); 184 } 185 free(opts, M_MOUNT); 186 } 187 188 /* 189 * Check if options are equal (with or without the "no" prefix). 190 */ 191 static int 192 vfs_equalopts(const char *opt1, const char *opt2) 193 { 194 195 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 196 if (strcmp(opt1, opt2) == 0) 197 return (1); 198 /* "noopt" vs. "opt" */ 199 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 200 return (1); 201 /* "opt" vs. "noopt" */ 202 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 203 return (1); 204 return (0); 205 } 206 207 /* 208 * If a mount option is specified several times, 209 * (with or without the "no" prefix) only keep 210 * the last occurence of it. 211 */ 212 static void 213 vfs_sanitizeopts(struct vfsoptlist *opts) 214 { 215 struct vfsopt *opt, *opt2, *tmp; 216 217 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 218 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 219 while (opt2 != NULL) { 220 if (vfs_equalopts(opt->name, opt2->name)) { 221 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 222 vfs_freeopt(opts, opt2); 223 opt2 = tmp; 224 } else { 225 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 226 } 227 } 228 } 229 } 230 231 /* 232 * Build a linked list of mount options from a struct uio. 233 */ 234 static int 235 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 236 { 237 struct vfsoptlist *opts; 238 struct vfsopt *opt; 239 size_t memused; 240 unsigned int i, iovcnt; 241 int error, namelen, optlen; 242 243 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 244 TAILQ_INIT(opts); 245 memused = 0; 246 iovcnt = auio->uio_iovcnt; 247 for (i = 0; i < iovcnt; i += 2) { 248 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 249 namelen = auio->uio_iov[i].iov_len; 250 optlen = auio->uio_iov[i + 1].iov_len; 251 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 252 opt->value = NULL; 253 opt->len = 0; 254 255 /* 256 * Do this early, so jumps to "bad" will free the current 257 * option. 258 */ 259 TAILQ_INSERT_TAIL(opts, opt, link); 260 memused += sizeof(struct vfsopt) + optlen + namelen; 261 262 /* 263 * Avoid consuming too much memory, and attempts to overflow 264 * memused. 265 */ 266 if (memused > VFS_MOUNTARG_SIZE_MAX || 267 optlen > VFS_MOUNTARG_SIZE_MAX || 268 namelen > VFS_MOUNTARG_SIZE_MAX) { 269 error = EINVAL; 270 goto bad; 271 } 272 273 if (auio->uio_segflg == UIO_SYSSPACE) { 274 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 275 } else { 276 error = copyin(auio->uio_iov[i].iov_base, opt->name, 277 namelen); 278 if (error) 279 goto bad; 280 } 281 /* Ensure names are null-terminated strings. */ 282 if (opt->name[namelen - 1] != '\0') { 283 error = EINVAL; 284 goto bad; 285 } 286 if (optlen != 0) { 287 opt->len = optlen; 288 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 289 if (auio->uio_segflg == UIO_SYSSPACE) { 290 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 291 optlen); 292 } else { 293 error = copyin(auio->uio_iov[i + 1].iov_base, 294 opt->value, optlen); 295 if (error) 296 goto bad; 297 } 298 } 299 } 300 vfs_sanitizeopts(opts); 301 *options = opts; 302 return (0); 303 bad: 304 vfs_freeopts(opts); 305 return (error); 306 } 307 308 /* 309 * Merge the old mount options with the new ones passed 310 * in the MNT_UPDATE case. 311 */ 312 static void 313 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 314 { 315 struct vfsopt *opt, *opt2, *new; 316 317 TAILQ_FOREACH(opt, opts, link) { 318 /* 319 * Check that this option hasn't been redefined 320 * nor cancelled with a "no" mount option. 321 */ 322 opt2 = TAILQ_FIRST(toopts); 323 while (opt2 != NULL) { 324 if (strcmp(opt2->name, opt->name) == 0) 325 goto next; 326 if (strncmp(opt2->name, "no", 2) == 0 && 327 strcmp(opt2->name + 2, opt->name) == 0) { 328 vfs_freeopt(toopts, opt2); 329 goto next; 330 } 331 opt2 = TAILQ_NEXT(opt2, link); 332 } 333 /* We want this option, duplicate it. */ 334 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 335 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 336 strcpy(new->name, opt->name); 337 if (opt->len != 0) { 338 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 339 bcopy(opt->value, new->value, opt->len); 340 } else { 341 new->value = NULL; 342 } 343 new->len = opt->len; 344 TAILQ_INSERT_TAIL(toopts, new, link); 345 next: 346 continue; 347 } 348 } 349 350 /* 351 * --------------------------------------------------------------------- 352 * Mount a filesystem 353 */ 354 int 355 nmount(td, uap) 356 struct thread *td; 357 struct nmount_args /* { 358 struct iovec *iovp; 359 unsigned int iovcnt; 360 int flags; 361 } */ *uap; 362 { 363 struct uio *auio; 364 struct iovec *iov; 365 unsigned int i; 366 int error; 367 u_int iovcnt; 368 369 /* Kick out MNT_ROOTFS early as it is legal internally */ 370 if (uap->flags & MNT_ROOTFS) 371 return (EINVAL); 372 373 iovcnt = uap->iovcnt; 374 /* 375 * Check that we have an even number of iovec's 376 * and that we have at least two options. 377 */ 378 if ((iovcnt & 1) || (iovcnt < 4)) 379 return (EINVAL); 380 381 error = copyinuio(uap->iovp, iovcnt, &auio); 382 if (error) 383 return (error); 384 iov = auio->uio_iov; 385 for (i = 0; i < iovcnt; i++) { 386 if (iov->iov_len > MMAXOPTIONLEN) { 387 free(auio, M_IOV); 388 return (EINVAL); 389 } 390 iov++; 391 } 392 error = vfs_donmount(td, uap->flags, auio); 393 free(auio, M_IOV); 394 return (error); 395 } 396 397 /* 398 * --------------------------------------------------------------------- 399 * Various utility functions 400 */ 401 402 /* 403 * Allocate and initialize the mount point struct. 404 */ 405 static int 406 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 407 const char *fspath, struct thread *td, struct mount **mpp) 408 { 409 struct mount *mp; 410 411 mp = malloc(sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO); 412 TAILQ_INIT(&mp->mnt_nvnodelist); 413 mp->mnt_nvnodelistsize = 0; 414 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 415 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 416 vfs_busy(mp, LK_NOWAIT, 0, td); 417 mp->mnt_op = vfsp->vfc_vfsops; 418 mp->mnt_vfc = vfsp; 419 vfsp->vfc_refcount++; 420 mp->mnt_stat.f_type = vfsp->vfc_typenum; 421 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 422 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 423 mp->mnt_vnodecovered = vp; 424 mp->mnt_cred = crdup(td->td_ucred); 425 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 426 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 427 mp->mnt_iosize_max = DFLTPHYS; 428 #ifdef MAC 429 mac_init_mount(mp); 430 mac_create_mount(td->td_ucred, mp); 431 #endif 432 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 433 *mpp = mp; 434 return (0); 435 } 436 437 /* 438 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 439 */ 440 static void 441 vfs_mount_destroy(struct mount *mp, struct thread *td) 442 { 443 444 mp->mnt_vfc->vfc_refcount--; 445 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) 446 panic("unmount: dangling vnode"); 447 vfs_unbusy(mp,td); 448 lockdestroy(&mp->mnt_lock); 449 MNT_ILOCK(mp); 450 if (mp->mnt_kern_flag & MNTK_MWAIT) 451 wakeup(mp); 452 MNT_IUNLOCK(mp); 453 mtx_destroy(&mp->mnt_mtx); 454 #ifdef MAC 455 mac_destroy_mount(mp); 456 #endif 457 if (mp->mnt_opt != NULL) 458 vfs_freeopts(mp->mnt_opt); 459 crfree(mp->mnt_cred); 460 free(mp, M_MOUNT); 461 } 462 463 static int 464 vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 465 { 466 struct vfsoptlist *optlist; 467 char *fstype, *fspath; 468 int error, fstypelen, fspathlen; 469 470 error = vfs_buildopts(fsoptions, &optlist); 471 if (error) 472 return (error); 473 474 /* 475 * We need these two options before the others, 476 * and they are mandatory for any filesystem. 477 * Ensure they are NUL terminated as well. 478 */ 479 fstypelen = 0; 480 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 481 if (error || fstype[fstypelen - 1] != '\0') { 482 error = EINVAL; 483 goto bail; 484 } 485 fspathlen = 0; 486 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 487 if (error || fspath[fspathlen - 1] != '\0') { 488 error = EINVAL; 489 goto bail; 490 } 491 492 /* 493 * Be ultra-paranoid about making sure the type and fspath 494 * variables will fit in our mp buffers, including the 495 * terminating NUL. 496 */ 497 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 498 error = ENAMETOOLONG; 499 goto bail; 500 } 501 502 mtx_lock(&Giant); 503 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 504 mtx_unlock(&Giant); 505 bail: 506 if (error) 507 vfs_freeopts(optlist); 508 return (error); 509 } 510 511 /* 512 * --------------------------------------------------------------------- 513 * Old mount API. 514 */ 515 #ifndef _SYS_SYSPROTO_H_ 516 struct mount_args { 517 char *type; 518 char *path; 519 int flags; 520 caddr_t data; 521 }; 522 #endif 523 /* ARGSUSED */ 524 int 525 mount(td, uap) 526 struct thread *td; 527 struct mount_args /* { 528 char *type; 529 char *path; 530 int flags; 531 caddr_t data; 532 } */ *uap; 533 { 534 char *fstype; 535 struct vfsconf *vfsp = NULL; 536 struct mntarg *ma = NULL; 537 int error; 538 539 /* Kick out MNT_ROOTFS early as it is legal internally */ 540 uap->flags &= ~MNT_ROOTFS; 541 542 if (uap->data == NULL) 543 return (EINVAL); 544 545 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 546 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 547 if (!error) { 548 mtx_lock(&Giant); /* XXX ? */ 549 vfsp = vfs_byname_kld(fstype, td, &error); 550 mtx_unlock(&Giant); 551 } 552 free(fstype, M_TEMP); 553 if (error) 554 return (error); 555 if (vfsp == NULL) 556 return (ENOENT); 557 if (vfsp->vfc_vfsops->vfs_cmount == NULL) 558 return (EOPNOTSUPP); 559 560 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 561 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 562 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 563 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 564 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 565 566 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 567 return (error); 568 } 569 570 571 /* 572 * vfs_domount(): actually attempt a filesystem mount. 573 */ 574 static int 575 vfs_domount( 576 struct thread *td, /* Flags common to all filesystems. */ 577 const char *fstype, /* Filesystem type. */ 578 char *fspath, /* Mount path. */ 579 int fsflags, /* Flags common to all filesystems. */ 580 void *fsdata /* Options local to the filesystem. */ 581 ) 582 { 583 struct vnode *vp; 584 struct mount *mp; 585 struct vfsconf *vfsp; 586 int error, flag = 0, kern_flag = 0; 587 struct vattr va; 588 struct nameidata nd; 589 590 mtx_assert(&Giant, MA_OWNED); 591 592 /* 593 * Be ultra-paranoid about making sure the type and fspath 594 * variables will fit in our mp buffers, including the 595 * terminating NUL. 596 */ 597 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 598 return (ENAMETOOLONG); 599 600 if (jailed(td->td_ucred)) 601 return (EPERM); 602 if (usermount == 0) { 603 if ((error = suser(td)) != 0) 604 return (error); 605 } 606 607 /* 608 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 609 */ 610 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 611 if ((error = suser(td)) != 0) 612 return (error); 613 } 614 /* 615 * Silently enforce MNT_NOSUID and MNT_USER for 616 * unprivileged users. 617 */ 618 if (suser(td) != 0) 619 fsflags |= MNT_NOSUID | MNT_USER; 620 /* 621 * Get vnode to be covered 622 */ 623 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, td); 624 if ((error = namei(&nd)) != 0) 625 return (error); 626 NDFREE(&nd, NDF_ONLY_PNBUF); 627 vp = nd.ni_vp; 628 if (fsflags & MNT_UPDATE) { 629 if ((vp->v_vflag & VV_ROOT) == 0) { 630 vput(vp); 631 return (EINVAL); 632 } 633 mp = vp->v_mount; 634 flag = mp->mnt_flag; 635 kern_flag = mp->mnt_kern_flag; 636 /* 637 * We only allow the filesystem to be reloaded if it 638 * is currently mounted read-only. 639 */ 640 if ((fsflags & MNT_RELOAD) && 641 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 642 vput(vp); 643 return (EOPNOTSUPP); /* Needs translation */ 644 } 645 /* 646 * Only privileged root, or (if MNT_USER is set) the user that 647 * did the original mount is permitted to update it. 648 */ 649 error = vfs_suser(mp, td); 650 if (error) { 651 vput(vp); 652 return (error); 653 } 654 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 655 vput(vp); 656 return (EBUSY); 657 } 658 VI_LOCK(vp); 659 if ((vp->v_iflag & VI_MOUNT) != 0 || 660 vp->v_mountedhere != NULL) { 661 VI_UNLOCK(vp); 662 vfs_unbusy(mp, td); 663 vput(vp); 664 return (EBUSY); 665 } 666 vp->v_iflag |= VI_MOUNT; 667 VI_UNLOCK(vp); 668 mp->mnt_flag |= fsflags & 669 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 670 VOP_UNLOCK(vp, 0, td); 671 mp->mnt_optnew = fsdata; 672 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 673 } else { 674 /* 675 * If the user is not root, ensure that they own the directory 676 * onto which we are attempting to mount. 677 */ 678 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 679 if (error) { 680 vput(vp); 681 return (error); 682 } 683 if (va.va_uid != td->td_ucred->cr_uid) { 684 if ((error = suser(td)) != 0) { 685 vput(vp); 686 return (error); 687 } 688 } 689 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 690 if (error != 0) { 691 vput(vp); 692 return (error); 693 } 694 if (vp->v_type != VDIR) { 695 vput(vp); 696 return (ENOTDIR); 697 } 698 vfsp = vfs_byname_kld(fstype, td, &error); 699 if (vfsp == NULL) { 700 vput(vp); 701 return (error); 702 } 703 VI_LOCK(vp); 704 if ((vp->v_iflag & VI_MOUNT) != 0 || 705 vp->v_mountedhere != NULL) { 706 VI_UNLOCK(vp); 707 vput(vp); 708 return (EBUSY); 709 } 710 vp->v_iflag |= VI_MOUNT; 711 VI_UNLOCK(vp); 712 713 /* 714 * Allocate and initialize the filesystem. 715 */ 716 error = vfs_mount_alloc(vp, vfsp, fspath, td, &mp); 717 if (error) { 718 vput(vp); 719 return (error); 720 } 721 VOP_UNLOCK(vp, 0, td); 722 723 /* XXXMAC: pass to vfs_mount_alloc? */ 724 mp->mnt_optnew = fsdata; 725 } 726 727 /* 728 * Set the mount level flags. 729 */ 730 if (fsflags & MNT_RDONLY) 731 mp->mnt_flag |= MNT_RDONLY; 732 mp->mnt_flag &=~ MNT_UPDATEMASK; 733 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS); 734 /* 735 * Mount the filesystem. 736 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 737 * get. No freeing of cn_pnbuf. 738 */ 739 error = VFS_MOUNT(mp, td); 740 if (!error) { 741 if (mp->mnt_opt != NULL) 742 vfs_freeopts(mp->mnt_opt); 743 mp->mnt_opt = mp->mnt_optnew; 744 VFS_STATFS(mp, &mp->mnt_stat, td); 745 } 746 /* 747 * Prevent external consumers of mount options from reading 748 * mnt_optnew. 749 */ 750 mp->mnt_optnew = NULL; 751 if (mp->mnt_flag & MNT_UPDATE) { 752 mp->mnt_flag &= 753 ~(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_SNAPSHOT); 754 if (error) { 755 mp->mnt_flag = flag; 756 mp->mnt_kern_flag = kern_flag; 757 } 758 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 759 if (mp->mnt_syncer == NULL) 760 error = vfs_allocate_syncvnode(mp); 761 } else { 762 if (mp->mnt_syncer != NULL) 763 vrele(mp->mnt_syncer); 764 mp->mnt_syncer = NULL; 765 } 766 vfs_unbusy(mp, td); 767 VI_LOCK(vp); 768 vp->v_iflag &= ~VI_MOUNT; 769 VI_UNLOCK(vp); 770 vrele(vp); 771 return (error); 772 } 773 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 774 /* 775 * Put the new filesystem on the mount list after root. 776 */ 777 cache_purge(vp); 778 if (!error) { 779 struct vnode *newdp; 780 781 VI_LOCK(vp); 782 vp->v_iflag &= ~VI_MOUNT; 783 VI_UNLOCK(vp); 784 vp->v_mountedhere = mp; 785 mtx_lock(&mountlist_mtx); 786 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 787 mtx_unlock(&mountlist_mtx); 788 vfs_event_signal(NULL, VQ_MOUNT, 0); 789 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 790 panic("mount: lost mount"); 791 mountcheckdirs(vp, newdp); 792 vput(newdp); 793 VOP_UNLOCK(vp, 0, td); 794 if ((mp->mnt_flag & MNT_RDONLY) == 0) 795 error = vfs_allocate_syncvnode(mp); 796 vfs_unbusy(mp, td); 797 if (error) 798 vrele(vp); 799 } else { 800 VI_LOCK(vp); 801 vp->v_iflag &= ~VI_MOUNT; 802 VI_UNLOCK(vp); 803 vfs_mount_destroy(mp, td); 804 vput(vp); 805 } 806 return (error); 807 } 808 809 /* 810 * --------------------------------------------------------------------- 811 * Unmount a filesystem. 812 * 813 * Note: unmount takes a path to the vnode mounted on as argument, 814 * not special file (as before). 815 */ 816 #ifndef _SYS_SYSPROTO_H_ 817 struct unmount_args { 818 char *path; 819 int flags; 820 }; 821 #endif 822 /* ARGSUSED */ 823 int 824 unmount(td, uap) 825 struct thread *td; 826 register struct unmount_args /* { 827 char *path; 828 int flags; 829 } */ *uap; 830 { 831 struct mount *mp; 832 char *pathbuf; 833 int error, id0, id1; 834 835 if (jailed(td->td_ucred)) 836 return (EPERM); 837 if (usermount == 0) { 838 if ((error = suser(td)) != 0) 839 return (error); 840 } 841 842 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 843 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 844 if (error) { 845 free(pathbuf, M_TEMP); 846 return (error); 847 } 848 if (uap->flags & MNT_BYFSID) { 849 /* Decode the filesystem ID. */ 850 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 851 free(pathbuf, M_TEMP); 852 return (EINVAL); 853 } 854 855 mtx_lock(&mountlist_mtx); 856 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 857 if (mp->mnt_stat.f_fsid.val[0] == id0 && 858 mp->mnt_stat.f_fsid.val[1] == id1) 859 break; 860 } 861 mtx_unlock(&mountlist_mtx); 862 } else { 863 mtx_lock(&mountlist_mtx); 864 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 865 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 866 break; 867 } 868 mtx_unlock(&mountlist_mtx); 869 } 870 free(pathbuf, M_TEMP); 871 if (mp == NULL) { 872 /* 873 * Previously we returned ENOENT for a nonexistent path and 874 * EINVAL for a non-mountpoint. We cannot tell these apart 875 * now, so in the !MNT_BYFSID case return the more likely 876 * EINVAL for compatibility. 877 */ 878 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 879 } 880 881 /* 882 * Only privileged root, or (if MNT_USER is set) the user that did the 883 * original mount is permitted to unmount this filesystem. 884 */ 885 error = vfs_suser(mp, td); 886 if (error) 887 return (error); 888 889 /* 890 * Don't allow unmounting the root filesystem. 891 */ 892 if (mp->mnt_flag & MNT_ROOTFS) 893 return (EINVAL); 894 mtx_lock(&Giant); 895 error = dounmount(mp, uap->flags, td); 896 mtx_unlock(&Giant); 897 return (error); 898 } 899 900 /* 901 * Do the actual filesystem unmount. 902 */ 903 int 904 dounmount(mp, flags, td) 905 struct mount *mp; 906 int flags; 907 struct thread *td; 908 { 909 struct vnode *coveredvp, *fsrootvp; 910 int error; 911 int async_flag; 912 913 mtx_assert(&Giant, MA_OWNED); 914 915 MNT_ILOCK(mp); 916 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 917 MNT_IUNLOCK(mp); 918 return (EBUSY); 919 } 920 mp->mnt_kern_flag |= MNTK_UNMOUNT; 921 /* Allow filesystems to detect that a forced unmount is in progress. */ 922 if (flags & MNT_FORCE) 923 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 924 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 925 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td); 926 if (error) { 927 MNT_ILOCK(mp); 928 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 929 if (mp->mnt_kern_flag & MNTK_MWAIT) 930 wakeup(mp); 931 MNT_IUNLOCK(mp); 932 return (error); 933 } 934 vn_start_write(NULL, &mp, V_WAIT); 935 936 if (mp->mnt_flag & MNT_EXPUBLIC) 937 vfs_setpublicfs(NULL, NULL, NULL); 938 939 vfs_msync(mp, MNT_WAIT); 940 async_flag = mp->mnt_flag & MNT_ASYNC; 941 mp->mnt_flag &= ~MNT_ASYNC; 942 cache_purgevfs(mp); /* remove cache entries for this file sys */ 943 if (mp->mnt_syncer != NULL) 944 vrele(mp->mnt_syncer); 945 /* 946 * For forced unmounts, move process cdir/rdir refs on the fs root 947 * vnode to the covered vnode. For non-forced unmounts we want 948 * such references to cause an EBUSY error. 949 */ 950 if ((flags & MNT_FORCE) && 951 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 952 if (mp->mnt_vnodecovered != NULL) 953 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 954 if (fsrootvp == rootvnode) { 955 vrele(rootvnode); 956 rootvnode = NULL; 957 } 958 vput(fsrootvp); 959 } 960 if (((mp->mnt_flag & MNT_RDONLY) || 961 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 962 (flags & MNT_FORCE)) { 963 error = VFS_UNMOUNT(mp, flags, td); 964 } 965 vn_finished_write(mp); 966 if (error) { 967 /* Undo cdir/rdir and rootvnode changes made above. */ 968 if ((flags & MNT_FORCE) && 969 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 970 if (mp->mnt_vnodecovered != NULL) 971 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 972 if (rootvnode == NULL) { 973 rootvnode = fsrootvp; 974 vref(rootvnode); 975 } 976 vput(fsrootvp); 977 } 978 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 979 (void) vfs_allocate_syncvnode(mp); 980 MNT_ILOCK(mp); 981 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 982 mp->mnt_flag |= async_flag; 983 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 984 if (mp->mnt_kern_flag & MNTK_MWAIT) 985 wakeup(mp); 986 MNT_IUNLOCK(mp); 987 return (error); 988 } 989 mtx_lock(&mountlist_mtx); 990 TAILQ_REMOVE(&mountlist, mp, mnt_list); 991 if ((coveredvp = mp->mnt_vnodecovered) != NULL) 992 coveredvp->v_mountedhere = NULL; 993 mtx_unlock(&mountlist_mtx); 994 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 995 vfs_mount_destroy(mp, td); 996 if (coveredvp != NULL) 997 vrele(coveredvp); 998 return (0); 999 } 1000 1001 /* 1002 * --------------------------------------------------------------------- 1003 * Mounting of root filesystem 1004 * 1005 */ 1006 1007 struct root_hold_token { 1008 const char *who; 1009 LIST_ENTRY(root_hold_token) list; 1010 }; 1011 1012 static LIST_HEAD(, root_hold_token) root_holds = 1013 LIST_HEAD_INITIALIZER(&root_holds); 1014 1015 struct root_hold_token * 1016 root_mount_hold(const char *identifier) 1017 { 1018 struct root_hold_token *h; 1019 1020 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1021 h->who = identifier; 1022 mtx_lock(&mountlist_mtx); 1023 LIST_INSERT_HEAD(&root_holds, h, list); 1024 mtx_unlock(&mountlist_mtx); 1025 return (h); 1026 } 1027 1028 void 1029 root_mount_rel(struct root_hold_token *h) 1030 { 1031 1032 mtx_lock(&mountlist_mtx); 1033 LIST_REMOVE(h, list); 1034 wakeup(&root_holds); 1035 mtx_unlock(&mountlist_mtx); 1036 free(h, M_DEVBUF); 1037 } 1038 1039 static void 1040 root_mount_wait(void) 1041 { 1042 struct root_hold_token *h; 1043 1044 for (;;) { 1045 DROP_GIANT(); 1046 g_waitidle(); 1047 PICKUP_GIANT(); 1048 mtx_lock(&mountlist_mtx); 1049 if (LIST_EMPTY(&root_holds)) { 1050 mtx_unlock(&mountlist_mtx); 1051 break; 1052 } 1053 printf("Root mount waiting for:"); 1054 LIST_FOREACH(h, &root_holds, list) 1055 printf(" %s", h->who); 1056 printf("\n"); 1057 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1058 hz); 1059 } 1060 } 1061 1062 static void 1063 set_rootvnode(struct thread *td) 1064 { 1065 struct proc *p; 1066 1067 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1068 panic("Cannot find root vnode"); 1069 1070 p = td->td_proc; 1071 FILEDESC_LOCK(p->p_fd); 1072 1073 if (p->p_fd->fd_cdir != NULL) 1074 vrele(p->p_fd->fd_cdir); 1075 p->p_fd->fd_cdir = rootvnode; 1076 VREF(rootvnode); 1077 1078 if (p->p_fd->fd_rdir != NULL) 1079 vrele(p->p_fd->fd_rdir); 1080 p->p_fd->fd_rdir = rootvnode; 1081 VREF(rootvnode); 1082 1083 FILEDESC_UNLOCK(p->p_fd); 1084 1085 VOP_UNLOCK(rootvnode, 0, td); 1086 } 1087 1088 /* 1089 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1090 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1091 */ 1092 1093 static void 1094 devfs_first(void) 1095 { 1096 struct thread *td = curthread; 1097 struct vfsconf *vfsp; 1098 struct mount *mp = NULL; 1099 int error; 1100 1101 vfsp = vfs_byname("devfs"); 1102 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1103 if (vfsp == NULL) 1104 return; 1105 1106 error = vfs_mount_alloc(NULLVP, vfsp, "/dev", td, &mp); 1107 KASSERT(error == 0, ("vfs_mount_alloc failed %d", error)); 1108 if (error) 1109 return; 1110 1111 error = VFS_MOUNT(mp, curthread); 1112 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1113 if (error) 1114 return; 1115 1116 mtx_lock(&mountlist_mtx); 1117 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1118 mtx_unlock(&mountlist_mtx); 1119 1120 set_rootvnode(td); 1121 1122 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1123 if (error) 1124 printf("kern_symlink /dev -> / returns %d\n", error); 1125 } 1126 1127 /* 1128 * Surgically move our devfs to be mounted on /dev. 1129 */ 1130 1131 static void 1132 devfs_fixup(struct thread *td) 1133 { 1134 struct nameidata nd; 1135 int error; 1136 struct vnode *vp, *dvp; 1137 struct mount *mp; 1138 1139 /* Remove our devfs mount from the mountlist and purge the cache */ 1140 mtx_lock(&mountlist_mtx); 1141 mp = TAILQ_FIRST(&mountlist); 1142 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1143 mtx_unlock(&mountlist_mtx); 1144 cache_purgevfs(mp); 1145 1146 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1147 VI_LOCK(dvp); 1148 dvp->v_iflag &= ~VI_MOUNT; 1149 dvp->v_mountedhere = NULL; 1150 VI_UNLOCK(dvp); 1151 1152 /* Set up the real rootvnode, and purge the cache */ 1153 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1154 set_rootvnode(td); 1155 cache_purgevfs(rootvnode->v_mount); 1156 1157 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1158 error = namei(&nd); 1159 if (error) { 1160 printf("Lookup of /dev for devfs, error: %d\n", error); 1161 return; 1162 } 1163 NDFREE(&nd, NDF_ONLY_PNBUF); 1164 vp = nd.ni_vp; 1165 if (vp->v_type != VDIR) { 1166 vput(vp); 1167 } 1168 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1169 if (error) { 1170 vput(vp); 1171 } 1172 cache_purge(vp); 1173 mp->mnt_vnodecovered = vp; 1174 vp->v_mountedhere = mp; 1175 mtx_lock(&mountlist_mtx); 1176 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1177 mtx_unlock(&mountlist_mtx); 1178 VOP_UNLOCK(vp, 0, td); 1179 vfs_unbusy(mp, td); 1180 vput(dvp); 1181 1182 /* Unlink the no longer needed /dev/dev -> / symlink */ 1183 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1184 } 1185 1186 /* 1187 * Find and mount the root filesystem 1188 */ 1189 void 1190 vfs_mountroot(void) 1191 { 1192 char *cp; 1193 int error, i, asked = 0; 1194 1195 root_mount_wait(); 1196 1197 devfs_first(); 1198 1199 /* 1200 * We are booted with instructions to prompt for the root filesystem. 1201 */ 1202 if (boothowto & RB_ASKNAME) { 1203 if (!vfs_mountroot_ask()) 1204 return; 1205 asked = 1; 1206 } 1207 1208 /* 1209 * The root filesystem information is compiled in, and we are 1210 * booted with instructions to use it. 1211 */ 1212 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1213 if (!vfs_mountroot_try(ctrootdevname)) 1214 return; 1215 ctrootdevname = NULL; 1216 } 1217 1218 /* 1219 * We've been given the generic "use CDROM as root" flag. This is 1220 * necessary because one media may be used in many different 1221 * devices, so we need to search for them. 1222 */ 1223 if (boothowto & RB_CDROM) { 1224 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1225 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1226 return; 1227 } 1228 } 1229 1230 /* 1231 * Try to use the value read by the loader from /etc/fstab, or 1232 * supplied via some other means. This is the preferred 1233 * mechanism. 1234 */ 1235 cp = getenv("vfs.root.mountfrom"); 1236 if (cp != NULL) { 1237 error = vfs_mountroot_try(cp); 1238 freeenv(cp); 1239 if (!error) 1240 return; 1241 } 1242 1243 /* 1244 * Try values that may have been computed by code during boot 1245 */ 1246 if (!vfs_mountroot_try(rootdevnames[0])) 1247 return; 1248 if (!vfs_mountroot_try(rootdevnames[1])) 1249 return; 1250 1251 /* 1252 * If we (still) have a compiled-in default, try it. 1253 */ 1254 if (ctrootdevname != NULL) 1255 if (!vfs_mountroot_try(ctrootdevname)) 1256 return; 1257 /* 1258 * Everything so far has failed, prompt on the console if we haven't 1259 * already tried that. 1260 */ 1261 if (!asked) 1262 if (!vfs_mountroot_ask()) 1263 return; 1264 1265 panic("Root mount failed, startup aborted."); 1266 } 1267 1268 /* 1269 * Mount (mountfrom) as the root filesystem. 1270 */ 1271 static int 1272 vfs_mountroot_try(const char *mountfrom) 1273 { 1274 struct mount *mp; 1275 char *vfsname, *path; 1276 int error; 1277 char patt[32]; 1278 1279 vfsname = NULL; 1280 path = NULL; 1281 mp = NULL; 1282 error = EINVAL; 1283 1284 if (mountfrom == NULL) 1285 return (error); /* don't complain */ 1286 printf("Trying to mount root from %s\n", mountfrom); 1287 1288 /* parse vfs name and path */ 1289 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1290 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1291 vfsname[0] = path[0] = 0; 1292 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1293 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1294 goto out; 1295 1296 if (path[0] == '\0') 1297 strcpy(path, ROOTNAME); 1298 1299 error = kernel_vmount( 1300 MNT_RDONLY | MNT_ROOTFS, 1301 "fstype", vfsname, 1302 "fspath", "/", 1303 "from", path, 1304 NULL); 1305 if (error == 0) { 1306 /* 1307 * We mount devfs prior to mounting the / FS, so the first 1308 * entry will typically be devfs. 1309 */ 1310 mp = TAILQ_FIRST(&mountlist); 1311 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1312 1313 /* 1314 * Iterate over all currently mounted file systems and use 1315 * the time stamp found to check and/or initialize the RTC. 1316 * Typically devfs has no time stamp and the only other FS 1317 * is the actual / FS. 1318 */ 1319 do { 1320 if (mp->mnt_time != 0) 1321 inittodr(mp->mnt_time); 1322 mp = TAILQ_NEXT(mp, mnt_list); 1323 } while (mp != NULL); 1324 1325 devfs_fixup(curthread); 1326 } 1327 out: 1328 free(path, M_MOUNT); 1329 free(vfsname, M_MOUNT); 1330 return (error); 1331 } 1332 1333 /* 1334 * --------------------------------------------------------------------- 1335 * Interactive root filesystem selection code. 1336 */ 1337 1338 static int 1339 vfs_mountroot_ask(void) 1340 { 1341 char name[128]; 1342 1343 for(;;) { 1344 printf("\nManual root filesystem specification:\n"); 1345 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1346 #if defined(__i386__) || defined(__ia64__) 1347 printf(" eg. ufs:da0s1a\n"); 1348 #else 1349 printf(" eg. ufs:/dev/da0a\n"); 1350 #endif 1351 printf(" ? List valid disk boot devices\n"); 1352 printf(" <empty line> Abort manual input\n"); 1353 printf("\nmountroot> "); 1354 gets(name, sizeof(name), 1); 1355 if (name[0] == '\0') 1356 return (1); 1357 if (name[0] == '?') { 1358 printf("\nList of GEOM managed disk devices:\n "); 1359 g_dev_print(); 1360 continue; 1361 } 1362 if (!vfs_mountroot_try(name)) 1363 return (0); 1364 } 1365 } 1366 1367 /* 1368 * --------------------------------------------------------------------- 1369 * Functions for querying mount options/arguments from filesystems. 1370 */ 1371 1372 /* 1373 * Check that no unknown options are given 1374 */ 1375 int 1376 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1377 { 1378 struct vfsopt *opt; 1379 const char **t, *p; 1380 1381 1382 TAILQ_FOREACH(opt, opts, link) { 1383 p = opt->name; 1384 if (p[0] == 'n' && p[1] == 'o') 1385 p += 2; 1386 for(t = global_opts; *t != NULL; t++) 1387 if (!strcmp(*t, p)) 1388 break; 1389 if (*t != NULL) 1390 continue; 1391 for(t = legal; *t != NULL; t++) 1392 if (!strcmp(*t, p)) 1393 break; 1394 if (*t != NULL) 1395 continue; 1396 printf("mount option <%s> is unknown\n", p); 1397 return (EINVAL); 1398 } 1399 return (0); 1400 } 1401 1402 /* 1403 * Get a mount option by its name. 1404 * 1405 * Return 0 if the option was found, ENOENT otherwise. 1406 * If len is non-NULL it will be filled with the length 1407 * of the option. If buf is non-NULL, it will be filled 1408 * with the address of the option. 1409 */ 1410 int 1411 vfs_getopt(opts, name, buf, len) 1412 struct vfsoptlist *opts; 1413 const char *name; 1414 void **buf; 1415 int *len; 1416 { 1417 struct vfsopt *opt; 1418 1419 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1420 1421 TAILQ_FOREACH(opt, opts, link) { 1422 if (strcmp(name, opt->name) == 0) { 1423 if (len != NULL) 1424 *len = opt->len; 1425 if (buf != NULL) 1426 *buf = opt->value; 1427 return (0); 1428 } 1429 } 1430 return (ENOENT); 1431 } 1432 1433 char * 1434 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1435 { 1436 struct vfsopt *opt; 1437 1438 *error = 0; 1439 TAILQ_FOREACH(opt, opts, link) { 1440 if (strcmp(name, opt->name) != 0) 1441 continue; 1442 if (((char *)opt->value)[opt->len - 1] != '\0') { 1443 *error = EINVAL; 1444 return (NULL); 1445 } 1446 return (opt->value); 1447 } 1448 return (NULL); 1449 } 1450 1451 int 1452 vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1453 { 1454 struct vfsopt *opt; 1455 1456 TAILQ_FOREACH(opt, opts, link) { 1457 if (strcmp(name, opt->name) == 0) { 1458 if (w != NULL) 1459 *w |= val; 1460 return (1); 1461 } 1462 } 1463 if (w != NULL) 1464 *w &= ~val; 1465 return (0); 1466 } 1467 1468 int 1469 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1470 { 1471 va_list ap; 1472 struct vfsopt *opt; 1473 int ret; 1474 1475 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1476 1477 TAILQ_FOREACH(opt, opts, link) { 1478 if (strcmp(name, opt->name) != 0) 1479 continue; 1480 if (((char *)opt->value)[opt->len - 1] != '\0') 1481 return (0); 1482 va_start(ap, fmt); 1483 ret = vsscanf(opt->value, fmt, ap); 1484 va_end(ap); 1485 return (ret); 1486 } 1487 return (0); 1488 } 1489 1490 /* 1491 * Find and copy a mount option. 1492 * 1493 * The size of the buffer has to be specified 1494 * in len, if it is not the same length as the 1495 * mount option, EINVAL is returned. 1496 * Returns ENOENT if the option is not found. 1497 */ 1498 int 1499 vfs_copyopt(opts, name, dest, len) 1500 struct vfsoptlist *opts; 1501 const char *name; 1502 void *dest; 1503 int len; 1504 { 1505 struct vfsopt *opt; 1506 1507 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1508 1509 TAILQ_FOREACH(opt, opts, link) { 1510 if (strcmp(name, opt->name) == 0) { 1511 if (len != opt->len) 1512 return (EINVAL); 1513 bcopy(opt->value, dest, opt->len); 1514 return (0); 1515 } 1516 } 1517 return (ENOENT); 1518 } 1519 1520 /* 1521 * This is a helper function for filesystems to traverse their 1522 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1523 */ 1524 1525 struct vnode * 1526 __mnt_vnode_next(struct vnode **nvp, struct mount *mp) 1527 { 1528 struct vnode *vp; 1529 1530 mtx_assert(&mp->mnt_mtx, MA_OWNED); 1531 1532 vp = *nvp; 1533 /* Check if we are done */ 1534 if (vp == NULL) 1535 return (NULL); 1536 /* If our next vnode is no longer ours, start over */ 1537 if (vp->v_mount != mp) 1538 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1539 /* Save pointer to next vnode in list */ 1540 if (vp != NULL) 1541 *nvp = TAILQ_NEXT(vp, v_nmntvnodes); 1542 else 1543 *nvp = NULL; 1544 return (vp); 1545 } 1546 1547 int 1548 __vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 1549 { 1550 int error; 1551 1552 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 1553 if (sbp != &mp->mnt_stat) 1554 *sbp = mp->mnt_stat; 1555 return (error); 1556 } 1557 1558 void 1559 vfs_mountedfrom(struct mount *mp, const char *from) 1560 { 1561 1562 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 1563 strlcpy(mp->mnt_stat.f_mntfromname, from, 1564 sizeof mp->mnt_stat.f_mntfromname); 1565 } 1566 1567 /* 1568 * --------------------------------------------------------------------- 1569 * This is the api for building mount args and mounting filesystems from 1570 * inside the kernel. 1571 * 1572 * The API works by accumulation of individual args. First error is 1573 * latched. 1574 * 1575 * XXX: should be documented in new manpage kernel_mount(9) 1576 */ 1577 1578 /* A memory allocation which must be freed when we are done */ 1579 struct mntaarg { 1580 SLIST_ENTRY(mntaarg) next; 1581 }; 1582 1583 /* The header for the mount arguments */ 1584 struct mntarg { 1585 struct iovec *v; 1586 int len; 1587 int error; 1588 SLIST_HEAD(, mntaarg) list; 1589 }; 1590 1591 /* 1592 * Add a boolean argument. 1593 * 1594 * flag is the boolean value. 1595 * name must start with "no". 1596 */ 1597 struct mntarg * 1598 mount_argb(struct mntarg *ma, int flag, const char *name) 1599 { 1600 1601 KASSERT(name[0] == 'n' && name[1] == 'o', 1602 ("mount_argb(...,%s): name must start with 'no'", name)); 1603 1604 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 1605 } 1606 1607 /* 1608 * Add an argument printf style 1609 */ 1610 struct mntarg * 1611 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 1612 { 1613 va_list ap; 1614 struct mntaarg *maa; 1615 struct sbuf *sb; 1616 int len; 1617 1618 if (ma == NULL) { 1619 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 1620 SLIST_INIT(&ma->list); 1621 } 1622 if (ma->error) 1623 return (ma); 1624 1625 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 1626 M_MOUNT, M_WAITOK); 1627 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 1628 ma->v[ma->len].iov_len = strlen(name) + 1; 1629 ma->len++; 1630 1631 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 1632 va_start(ap, fmt); 1633 sbuf_vprintf(sb, fmt, ap); 1634 va_end(ap); 1635 sbuf_finish(sb); 1636 len = sbuf_len(sb) + 1; 1637 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 1638 SLIST_INSERT_HEAD(&ma->list, maa, next); 1639 bcopy(sbuf_data(sb), maa + 1, len); 1640 sbuf_delete(sb); 1641 1642 ma->v[ma->len].iov_base = maa + 1; 1643 ma->v[ma->len].iov_len = len; 1644 ma->len++; 1645 1646 return (ma); 1647 } 1648 1649 /* 1650 * Add an argument which is a userland string. 1651 */ 1652 struct mntarg * 1653 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 1654 { 1655 struct mntaarg *maa; 1656 char *tbuf; 1657 1658 if (val == NULL) 1659 return (ma); 1660 if (ma == NULL) { 1661 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 1662 SLIST_INIT(&ma->list); 1663 } 1664 if (ma->error) 1665 return (ma); 1666 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 1667 SLIST_INSERT_HEAD(&ma->list, maa, next); 1668 tbuf = (void *)(maa + 1); 1669 ma->error = copyinstr(val, tbuf, len, NULL); 1670 return (mount_arg(ma, name, tbuf, -1)); 1671 } 1672 1673 /* 1674 * Plain argument. 1675 * 1676 * If length is -1, use printf. 1677 */ 1678 struct mntarg * 1679 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 1680 { 1681 1682 if (ma == NULL) { 1683 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 1684 SLIST_INIT(&ma->list); 1685 } 1686 if (ma->error) 1687 return (ma); 1688 1689 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 1690 M_MOUNT, M_WAITOK); 1691 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 1692 ma->v[ma->len].iov_len = strlen(name) + 1; 1693 ma->len++; 1694 1695 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 1696 if (len < 0) 1697 ma->v[ma->len].iov_len = strlen(val) + 1; 1698 else 1699 ma->v[ma->len].iov_len = len; 1700 ma->len++; 1701 return (ma); 1702 } 1703 1704 /* 1705 * Free a mntarg structure 1706 */ 1707 static void 1708 free_mntarg(struct mntarg *ma) 1709 { 1710 struct mntaarg *maa; 1711 1712 while (!SLIST_EMPTY(&ma->list)) { 1713 maa = SLIST_FIRST(&ma->list); 1714 SLIST_REMOVE_HEAD(&ma->list, next); 1715 free(maa, M_MOUNT); 1716 } 1717 free(ma->v, M_MOUNT); 1718 free(ma, M_MOUNT); 1719 } 1720 1721 /* 1722 * Mount a filesystem 1723 */ 1724 int 1725 kernel_mount(struct mntarg *ma, int flags) 1726 { 1727 struct uio auio; 1728 int error; 1729 1730 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 1731 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 1732 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 1733 1734 auio.uio_iov = ma->v; 1735 auio.uio_iovcnt = ma->len; 1736 auio.uio_segflg = UIO_SYSSPACE; 1737 1738 error = ma->error; 1739 if (!error) 1740 error = vfs_donmount(curthread, flags, &auio); 1741 free_mntarg(ma); 1742 return (error); 1743 } 1744 1745 /* 1746 * A printflike function to mount a filesystem. 1747 */ 1748 int 1749 kernel_vmount(int flags, ...) 1750 { 1751 struct mntarg *ma = NULL; 1752 va_list ap; 1753 const char *cp; 1754 const void *vp; 1755 int error; 1756 1757 va_start(ap, flags); 1758 for (;;) { 1759 cp = va_arg(ap, const char *); 1760 if (cp == NULL) 1761 break; 1762 vp = va_arg(ap, const void *); 1763 ma = mount_arg(ma, cp, vp, -1); 1764 } 1765 va_end(ap); 1766 1767 error = kernel_mount(ma, flags); 1768 return (error); 1769 }
Cache object: b9dbadb1cf5537e06552bc7ca5f68b9b
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]