vfs_mount.c revision 176283
1/*- 2 * Copyright (c) 1999-2004 Poul-Henning Kamp 3 * Copyright (c) 1999 Michael Smith 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/kern/vfs_mount.c 176283 2008-02-14 17:04:31Z yar $"); 39 40#include <sys/param.h> 41#include <sys/conf.h> 42#include <sys/clock.h> 43#include <sys/jail.h> 44#include <sys/kernel.h> 45#include <sys/libkern.h> 46#include <sys/malloc.h> 47#include <sys/mount.h> 48#include <sys/mutex.h> 49#include <sys/namei.h> 50#include <sys/priv.h> 51#include <sys/proc.h> 52#include <sys/filedesc.h> 53#include <sys/reboot.h> 54#include <sys/syscallsubr.h> 55#include <sys/sysproto.h> 56#include <sys/sx.h> 57#include <sys/sysctl.h> 58#include <sys/sysent.h> 59#include <sys/systm.h> 60#include <sys/vnode.h> 61#include <vm/uma.h> 62 63#include <geom/geom.h> 64 65#include <machine/stdarg.h> 66 67#include <security/audit/audit.h> 68#include <security/mac/mac_framework.h> 69 70#include "opt_rootdevname.h" 71#include "opt_ddb.h" 72#include "opt_mac.h" 73 74#ifdef DDB 75#include <ddb/ddb.h> 76#endif 77 78#define ROOTNAME "root_device" 79#define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 80 81static int vfs_domount(struct thread *td, const char *fstype, 82 char *fspath, int fsflags, void *fsdata); 83static int vfs_mountroot_ask(void); 84static int vfs_mountroot_try(const char *mountfrom); 85static int vfs_donmount(struct thread *td, int fsflags, 86 struct uio *fsoptions); 87static void free_mntarg(struct mntarg *ma); 88static int vfs_getopt_pos(struct vfsoptlist *opts, const char *name); 89 90static int usermount = 0; 91SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 92 "Unprivileged users may mount and unmount file systems"); 93 94MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 95MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 96static uma_zone_t mount_zone; 97 98/* List of mounted filesystems. */ 99struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 100 101/* For any iteration/modification of mountlist */ 102struct mtx mountlist_mtx; 103MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 104 105TAILQ_HEAD(vfsoptlist, vfsopt); 106struct vfsopt { 107 TAILQ_ENTRY(vfsopt) link; 108 char *name; 109 void *value; 110 int len; 111}; 112 113/* 114 * The vnode of the system's root (/ in the filesystem, without chroot 115 * active.) 116 */ 117struct vnode *rootvnode; 118 119/* 120 * The root filesystem is detailed in the kernel environment variable 121 * vfs.root.mountfrom, which is expected to be in the general format 122 * 123 * <vfsname>:[<path>] 124 * vfsname := the name of a VFS known to the kernel and capable 125 * of being mounted as root 126 * path := disk device name or other data used by the filesystem 127 * to locate its physical store 128 */ 129 130/* 131 * Global opts, taken by all filesystems 132 */ 133static const char *global_opts[] = { 134 "errmsg", 135 "fstype", 136 "fspath", 137 "ro", 138 "rw", 139 "nosuid", 140 "noexec", 141 "update", 142 NULL 143}; 144 145/* 146 * The root specifiers we will try if RB_CDROM is specified. 147 */ 148static char *cdrom_rootdevnames[] = { 149 "cd9660:cd0", 150 "cd9660:acd0", 151 NULL 152}; 153 154/* legacy find-root code */ 155char *rootdevnames[2] = {NULL, NULL}; 156#ifndef ROOTDEVNAME 157# define ROOTDEVNAME NULL 158#endif 159static const char *ctrootdevname = ROOTDEVNAME; 160 161/* 162 * --------------------------------------------------------------------- 163 * Functions for building and sanitizing the mount options 164 */ 165 166/* Remove one mount option. */ 167static void 168vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 169{ 170 171 TAILQ_REMOVE(opts, opt, link); 172 free(opt->name, M_MOUNT); 173 if (opt->value != NULL) 174 free(opt->value, M_MOUNT); 175#ifdef INVARIANTS 176 else if (opt->len != 0) 177 panic("%s: mount option with NULL value but length != 0", 178 __func__); 179#endif 180 free(opt, M_MOUNT); 181} 182 183/* Release all resources related to the mount options. */ 184void 185vfs_freeopts(struct vfsoptlist *opts) 186{ 187 struct vfsopt *opt; 188 189 while (!TAILQ_EMPTY(opts)) { 190 opt = TAILQ_FIRST(opts); 191 vfs_freeopt(opts, opt); 192 } 193 free(opts, M_MOUNT); 194} 195 196void 197vfs_deleteopt(struct vfsoptlist *opts, const char *name) 198{ 199 struct vfsopt *opt, *temp; 200 201 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 202 if (strcmp(opt->name, name) == 0) 203 vfs_freeopt(opts, opt); 204 } 205} 206 207/* 208 * Check if options are equal (with or without the "no" prefix). 209 */ 210static int 211vfs_equalopts(const char *opt1, const char *opt2) 212{ 213 214 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 215 if (strcmp(opt1, opt2) == 0) 216 return (1); 217 /* "noopt" vs. "opt" */ 218 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 219 return (1); 220 /* "opt" vs. "noopt" */ 221 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 222 return (1); 223 return (0); 224} 225 226/* 227 * If a mount option is specified several times, 228 * (with or without the "no" prefix) only keep 229 * the last occurence of it. 230 */ 231static void 232vfs_sanitizeopts(struct vfsoptlist *opts) 233{ 234 struct vfsopt *opt, *opt2, *tmp; 235 236 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 237 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 238 while (opt2 != NULL) { 239 if (vfs_equalopts(opt->name, opt2->name)) { 240 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 241 vfs_freeopt(opts, opt2); 242 opt2 = tmp; 243 } else { 244 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 245 } 246 } 247 } 248} 249 250/* 251 * Build a linked list of mount options from a struct uio. 252 */ 253static int 254vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 255{ 256 struct vfsoptlist *opts; 257 struct vfsopt *opt; 258 size_t memused; 259 unsigned int i, iovcnt; 260 int error, namelen, optlen; 261 262 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 263 TAILQ_INIT(opts); 264 memused = 0; 265 iovcnt = auio->uio_iovcnt; 266 for (i = 0; i < iovcnt; i += 2) { 267 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 268 namelen = auio->uio_iov[i].iov_len; 269 optlen = auio->uio_iov[i + 1].iov_len; 270 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 271 opt->value = NULL; 272 opt->len = 0; 273 274 /* 275 * Do this early, so jumps to "bad" will free the current 276 * option. 277 */ 278 TAILQ_INSERT_TAIL(opts, opt, link); 279 memused += sizeof(struct vfsopt) + optlen + namelen; 280 281 /* 282 * Avoid consuming too much memory, and attempts to overflow 283 * memused. 284 */ 285 if (memused > VFS_MOUNTARG_SIZE_MAX || 286 optlen > VFS_MOUNTARG_SIZE_MAX || 287 namelen > VFS_MOUNTARG_SIZE_MAX) { 288 error = EINVAL; 289 goto bad; 290 } 291 292 if (auio->uio_segflg == UIO_SYSSPACE) { 293 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 294 } else { 295 error = copyin(auio->uio_iov[i].iov_base, opt->name, 296 namelen); 297 if (error) 298 goto bad; 299 } 300 /* Ensure names are null-terminated strings. */ 301 if (opt->name[namelen - 1] != '\0') { 302 error = EINVAL; 303 goto bad; 304 } 305 if (optlen != 0) { 306 opt->len = optlen; 307 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 308 if (auio->uio_segflg == UIO_SYSSPACE) { 309 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 310 optlen); 311 } else { 312 error = copyin(auio->uio_iov[i + 1].iov_base, 313 opt->value, optlen); 314 if (error) 315 goto bad; 316 } 317 } 318 } 319 vfs_sanitizeopts(opts); 320 *options = opts; 321 return (0); 322bad: 323 vfs_freeopts(opts); 324 return (error); 325} 326 327/* 328 * Merge the old mount options with the new ones passed 329 * in the MNT_UPDATE case. 330 */ 331static void 332vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 333{ 334 struct vfsopt *opt, *opt2, *new; 335 336 TAILQ_FOREACH(opt, opts, link) { 337 /* 338 * Check that this option hasn't been redefined 339 * nor cancelled with a "no" mount option. 340 */ 341 opt2 = TAILQ_FIRST(toopts); 342 while (opt2 != NULL) { 343 if (strcmp(opt2->name, opt->name) == 0) 344 goto next; 345 if (strncmp(opt2->name, "no", 2) == 0 && 346 strcmp(opt2->name + 2, opt->name) == 0) { 347 vfs_freeopt(toopts, opt2); 348 goto next; 349 } 350 opt2 = TAILQ_NEXT(opt2, link); 351 } 352 /* We want this option, duplicate it. */ 353 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 354 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 355 strcpy(new->name, opt->name); 356 if (opt->len != 0) { 357 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 358 bcopy(opt->value, new->value, opt->len); 359 } else { 360 new->value = NULL; 361 } 362 new->len = opt->len; 363 TAILQ_INSERT_TAIL(toopts, new, link); 364next: 365 continue; 366 } 367} 368 369/* 370 * Mount a filesystem. 371 */ 372int 373nmount(td, uap) 374 struct thread *td; 375 struct nmount_args /* { 376 struct iovec *iovp; 377 unsigned int iovcnt; 378 int flags; 379 } */ *uap; 380{ 381 struct uio *auio; 382 struct iovec *iov; 383 unsigned int i; 384 int error; 385 u_int iovcnt; 386 387 AUDIT_ARG(fflags, uap->flags); 388 389 /* 390 * Filter out MNT_ROOTFS. We do not want clients of nmount() in 391 * userspace to set this flag, but we must filter it out if we want 392 * MNT_UPDATE on the root file system to work. 393 * MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try(). 394 */ 395 uap->flags &= ~MNT_ROOTFS; 396 397 iovcnt = uap->iovcnt; 398 /* 399 * Check that we have an even number of iovec's 400 * and that we have at least two options. 401 */ 402 if ((iovcnt & 1) || (iovcnt < 4)) 403 return (EINVAL); 404 405 error = copyinuio(uap->iovp, iovcnt, &auio); 406 if (error) 407 return (error); 408 iov = auio->uio_iov; 409 for (i = 0; i < iovcnt; i++) { 410 if (iov->iov_len > MMAXOPTIONLEN) { 411 free(auio, M_IOV); 412 return (EINVAL); 413 } 414 iov++; 415 } 416 error = vfs_donmount(td, uap->flags, auio); 417 418 free(auio, M_IOV); 419 return (error); 420} 421 422/* 423 * --------------------------------------------------------------------- 424 * Various utility functions 425 */ 426 427void 428vfs_ref(struct mount *mp) 429{ 430 431 MNT_ILOCK(mp); 432 MNT_REF(mp); 433 MNT_IUNLOCK(mp); 434} 435 436void 437vfs_rel(struct mount *mp) 438{ 439 440 MNT_ILOCK(mp); 441 MNT_REL(mp); 442 MNT_IUNLOCK(mp); 443} 444 445static int 446mount_init(void *mem, int size, int flags) 447{ 448 struct mount *mp; 449 450 mp = (struct mount *)mem; 451 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 452 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 453 return (0); 454} 455 456static void 457mount_fini(void *mem, int size) 458{ 459 struct mount *mp; 460 461 mp = (struct mount *)mem; 462 lockdestroy(&mp->mnt_lock); 463 mtx_destroy(&mp->mnt_mtx); 464} 465 466/* 467 * Allocate and initialize the mount point struct. 468 */ 469struct mount * 470vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 471 const char *fspath, struct thread *td) 472{ 473 struct mount *mp; 474 475 mp = uma_zalloc(mount_zone, M_WAITOK); 476 bzero(&mp->mnt_startzero, 477 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 478 TAILQ_INIT(&mp->mnt_nvnodelist); 479 mp->mnt_nvnodelistsize = 0; 480 mp->mnt_ref = 0; 481 (void) vfs_busy(mp, LK_NOWAIT, 0, td); 482 mp->mnt_op = vfsp->vfc_vfsops; 483 mp->mnt_vfc = vfsp; 484 vfsp->vfc_refcount++; /* XXX Unlocked */ 485 mp->mnt_stat.f_type = vfsp->vfc_typenum; 486 mp->mnt_gen++; 487 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 488 mp->mnt_vnodecovered = vp; 489 mp->mnt_cred = crdup(td->td_ucred); 490 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 491 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 492 mp->mnt_iosize_max = DFLTPHYS; 493#ifdef MAC 494 mac_mount_init(mp); 495 mac_mount_create(td->td_ucred, mp); 496#endif 497 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 498 return (mp); 499} 500 501/* 502 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 503 */ 504void 505vfs_mount_destroy(struct mount *mp) 506{ 507 int i; 508 509 MNT_ILOCK(mp); 510 for (i = 0; mp->mnt_ref && i < 3; i++) 511 msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz); 512 /* 513 * This will always cause a 3 second delay in rebooting due to 514 * refs on the root mountpoint that never go away. Most of these 515 * are held by init which never exits. 516 */ 517 if (i == 3 && (!rebooting || bootverbose)) 518 printf("Mount point %s had %d dangling refs\n", 519 mp->mnt_stat.f_mntonname, mp->mnt_ref); 520 if (mp->mnt_holdcnt != 0) { 521 printf("Waiting for mount point to be unheld\n"); 522 while (mp->mnt_holdcnt != 0) { 523 mp->mnt_holdcntwaiters++; 524 msleep(&mp->mnt_holdcnt, MNT_MTX(mp), 525 PZERO, "mntdestroy", 0); 526 mp->mnt_holdcntwaiters--; 527 } 528 printf("mount point unheld\n"); 529 } 530 if (mp->mnt_writeopcount > 0) { 531 printf("Waiting for mount point write ops\n"); 532 while (mp->mnt_writeopcount > 0) { 533 mp->mnt_kern_flag |= MNTK_SUSPEND; 534 msleep(&mp->mnt_writeopcount, 535 MNT_MTX(mp), 536 PZERO, "mntdestroy2", 0); 537 } 538 printf("mount point write ops completed\n"); 539 } 540 if (mp->mnt_secondary_writes > 0) { 541 printf("Waiting for mount point secondary write ops\n"); 542 while (mp->mnt_secondary_writes > 0) { 543 mp->mnt_kern_flag |= MNTK_SUSPEND; 544 msleep(&mp->mnt_secondary_writes, 545 MNT_MTX(mp), 546 PZERO, "mntdestroy3", 0); 547 } 548 printf("mount point secondary write ops completed\n"); 549 } 550 MNT_IUNLOCK(mp); 551 mp->mnt_vfc->vfc_refcount--; 552 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 553 struct vnode *vp; 554 555 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 556 vprint("", vp); 557 panic("unmount: dangling vnode"); 558 } 559 MNT_ILOCK(mp); 560 if (mp->mnt_kern_flag & MNTK_MWAIT) 561 wakeup(mp); 562 if (mp->mnt_writeopcount != 0) 563 panic("vfs_mount_destroy: nonzero writeopcount"); 564 if (mp->mnt_secondary_writes != 0) 565 panic("vfs_mount_destroy: nonzero secondary_writes"); 566 if (mp->mnt_nvnodelistsize != 0) 567 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 568 mp->mnt_writeopcount = -1000; 569 mp->mnt_nvnodelistsize = -1000; 570 mp->mnt_secondary_writes = -1000; 571 MNT_IUNLOCK(mp); 572#ifdef MAC 573 mac_mount_destroy(mp); 574#endif 575 if (mp->mnt_opt != NULL) 576 vfs_freeopts(mp->mnt_opt); 577 crfree(mp->mnt_cred); 578 uma_zfree(mount_zone, mp); 579} 580 581static int 582vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 583{ 584 struct vfsoptlist *optlist; 585 struct vfsopt *opt, *noro_opt; 586 char *fstype, *fspath, *errmsg; 587 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 588 int has_rw, has_noro; 589 590 errmsg = NULL; 591 errmsg_len = 0; 592 errmsg_pos = -1; 593 has_rw = 0; 594 has_noro = 0; 595 596 error = vfs_buildopts(fsoptions, &optlist); 597 if (error) 598 return (error); 599 600 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 601 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 602 603 /* 604 * We need these two options before the others, 605 * and they are mandatory for any filesystem. 606 * Ensure they are NUL terminated as well. 607 */ 608 fstypelen = 0; 609 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 610 if (error || fstype[fstypelen - 1] != '\0') { 611 error = EINVAL; 612 if (errmsg != NULL) 613 strncpy(errmsg, "Invalid fstype", errmsg_len); 614 goto bail; 615 } 616 fspathlen = 0; 617 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 618 if (error || fspath[fspathlen - 1] != '\0') { 619 error = EINVAL; 620 if (errmsg != NULL) 621 strncpy(errmsg, "Invalid fspath", errmsg_len); 622 goto bail; 623 } 624 625 /* 626 * We need to see if we have the "update" option 627 * before we call vfs_domount(), since vfs_domount() has special 628 * logic based on MNT_UPDATE. This is very important 629 * when we want to update the root filesystem. 630 */ 631 TAILQ_FOREACH(opt, optlist, link) { 632 if (strcmp(opt->name, "update") == 0) 633 fsflags |= MNT_UPDATE; 634 else if (strcmp(opt->name, "async") == 0) 635 fsflags |= MNT_ASYNC; 636 else if (strcmp(opt->name, "force") == 0) 637 fsflags |= MNT_FORCE; 638 else if (strcmp(opt->name, "multilabel") == 0) 639 fsflags |= MNT_MULTILABEL; 640 else if (strcmp(opt->name, "noasync") == 0) 641 fsflags &= ~MNT_ASYNC; 642 else if (strcmp(opt->name, "noatime") == 0) 643 fsflags |= MNT_NOATIME; 644 else if (strcmp(opt->name, "atime") == 0) { 645 free(opt->name, M_MOUNT); 646 opt->name = strdup("nonoatime", M_MOUNT); 647 } 648 else if (strcmp(opt->name, "noclusterr") == 0) 649 fsflags |= MNT_NOCLUSTERR; 650 else if (strcmp(opt->name, "clusterr") == 0) { 651 free(opt->name, M_MOUNT); 652 opt->name = strdup("nonoclusterr", M_MOUNT); 653 } 654 else if (strcmp(opt->name, "noclusterw") == 0) 655 fsflags |= MNT_NOCLUSTERW; 656 else if (strcmp(opt->name, "clusterw") == 0) { 657 free(opt->name, M_MOUNT); 658 opt->name = strdup("nonoclusterw", M_MOUNT); 659 } 660 else if (strcmp(opt->name, "noexec") == 0) 661 fsflags |= MNT_NOEXEC; 662 else if (strcmp(opt->name, "exec") == 0) { 663 free(opt->name, M_MOUNT); 664 opt->name = strdup("nonoexec", M_MOUNT); 665 } 666 else if (strcmp(opt->name, "nosuid") == 0) 667 fsflags |= MNT_NOSUID; 668 else if (strcmp(opt->name, "suid") == 0) { 669 free(opt->name, M_MOUNT); 670 opt->name = strdup("nonosuid", M_MOUNT); 671 } 672 else if (strcmp(opt->name, "nosymfollow") == 0) 673 fsflags |= MNT_NOSYMFOLLOW; 674 else if (strcmp(opt->name, "symfollow") == 0) { 675 free(opt->name, M_MOUNT); 676 opt->name = strdup("nonosymfollow", M_MOUNT); 677 } 678 else if (strcmp(opt->name, "noro") == 0) { 679 fsflags &= ~MNT_RDONLY; 680 has_noro = 1; 681 } 682 else if (strcmp(opt->name, "rw") == 0) { 683 fsflags &= ~MNT_RDONLY; 684 has_rw = 1; 685 } 686 else if (strcmp(opt->name, "ro") == 0) 687 fsflags |= MNT_RDONLY; 688 else if (strcmp(opt->name, "rdonly") == 0) { 689 free(opt->name, M_MOUNT); 690 opt->name = strdup("ro", M_MOUNT); 691 fsflags |= MNT_RDONLY; 692 } 693 else if (strcmp(opt->name, "snapshot") == 0) 694 fsflags |= MNT_SNAPSHOT; 695 else if (strcmp(opt->name, "suiddir") == 0) 696 fsflags |= MNT_SUIDDIR; 697 else if (strcmp(opt->name, "sync") == 0) 698 fsflags |= MNT_SYNCHRONOUS; 699 else if (strcmp(opt->name, "union") == 0) 700 fsflags |= MNT_UNION; 701 } 702 703 /* 704 * If "rw" was specified as a mount option, and we 705 * are trying to update a mount-point from "ro" to "rw", 706 * we need a mount option "noro", since in vfs_mergeopts(), 707 * "noro" will cancel "ro", but "rw" will not do anything. 708 */ 709 if (has_rw && !has_noro) { 710 noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 711 noro_opt->name = strdup("noro", M_MOUNT); 712 noro_opt->value = NULL; 713 noro_opt->len = 0; 714 TAILQ_INSERT_TAIL(optlist, noro_opt, link); 715 } 716 717 /* 718 * Be ultra-paranoid about making sure the type and fspath 719 * variables will fit in our mp buffers, including the 720 * terminating NUL. 721 */ 722 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 723 error = ENAMETOOLONG; 724 goto bail; 725 } 726 727 mtx_lock(&Giant); 728 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 729 mtx_unlock(&Giant); 730bail: 731 /* copyout the errmsg */ 732 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 733 && errmsg_len > 0 && errmsg != NULL) { 734 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 735 bcopy(errmsg, 736 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 737 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 738 } else { 739 copyout(errmsg, 740 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 741 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 742 } 743 } 744 745 if (error != 0) 746 vfs_freeopts(optlist); 747 return (error); 748} 749 750/* 751 * Old mount API. 752 */ 753#ifndef _SYS_SYSPROTO_H_ 754struct mount_args { 755 char *type; 756 char *path; 757 int flags; 758 caddr_t data; 759}; 760#endif 761/* ARGSUSED */ 762int 763mount(td, uap) 764 struct thread *td; 765 struct mount_args /* { 766 char *type; 767 char *path; 768 int flags; 769 caddr_t data; 770 } */ *uap; 771{ 772 char *fstype; 773 struct vfsconf *vfsp = NULL; 774 struct mntarg *ma = NULL; 775 int error; 776 777 AUDIT_ARG(fflags, uap->flags); 778 779 /* 780 * Filter out MNT_ROOTFS. We do not want clients of mount() in 781 * userspace to set this flag, but we must filter it out if we want 782 * MNT_UPDATE on the root file system to work. 783 * MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try(). 784 */ 785 uap->flags &= ~MNT_ROOTFS; 786 787 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 788 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 789 if (error) { 790 free(fstype, M_TEMP); 791 return (error); 792 } 793 794 AUDIT_ARG(text, fstype); 795 mtx_lock(&Giant); 796 vfsp = vfs_byname_kld(fstype, td, &error); 797 free(fstype, M_TEMP); 798 if (vfsp == NULL) { 799 mtx_unlock(&Giant); 800 return (ENOENT); 801 } 802 if (vfsp->vfc_vfsops->vfs_cmount == NULL) { 803 mtx_unlock(&Giant); 804 return (EOPNOTSUPP); 805 } 806 807 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 808 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 809 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 810 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 811 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 812 813 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 814 mtx_unlock(&Giant); 815 return (error); 816} 817 818 819/* 820 * vfs_domount(): actually attempt a filesystem mount. 821 */ 822static int 823vfs_domount( 824 struct thread *td, /* Calling thread. */ 825 const char *fstype, /* Filesystem type. */ 826 char *fspath, /* Mount path. */ 827 int fsflags, /* Flags common to all filesystems. */ 828 void *fsdata /* Options local to the filesystem. */ 829 ) 830{ 831 struct vnode *vp; 832 struct mount *mp; 833 struct vfsconf *vfsp; 834 struct export_args export; 835 int error, flag = 0; 836 struct vattr va; 837 struct nameidata nd; 838 839 mtx_assert(&Giant, MA_OWNED); 840 /* 841 * Be ultra-paranoid about making sure the type and fspath 842 * variables will fit in our mp buffers, including the 843 * terminating NUL. 844 */ 845 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 846 return (ENAMETOOLONG); 847 848 if (jailed(td->td_ucred) || usermount == 0) { 849 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 850 return (error); 851 } 852 853 /* 854 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 855 */ 856 if (fsflags & MNT_EXPORTED) { 857 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 858 if (error) 859 return (error); 860 } 861 if (fsflags & MNT_SUIDDIR) { 862 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 863 if (error) 864 return (error); 865 } 866 /* 867 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 868 */ 869 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 870 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 871 fsflags |= MNT_NOSUID | MNT_USER; 872 } 873 874 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 875 vfsp = NULL; 876 if ((fsflags & MNT_UPDATE) == 0) { 877 /* Don't try to load KLDs if we're mounting the root. */ 878 if (fsflags & MNT_ROOTFS) 879 vfsp = vfs_byname(fstype); 880 else 881 vfsp = vfs_byname_kld(fstype, td, &error); 882 if (vfsp == NULL) 883 return (ENODEV); 884 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL)) 885 return (EPERM); 886 } 887 /* 888 * Get vnode to be covered 889 */ 890 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE, 891 fspath, td); 892 if ((error = namei(&nd)) != 0) 893 return (error); 894 NDFREE(&nd, NDF_ONLY_PNBUF); 895 vp = nd.ni_vp; 896 if (fsflags & MNT_UPDATE) { 897 if ((vp->v_vflag & VV_ROOT) == 0) { 898 vput(vp); 899 return (EINVAL); 900 } 901 mp = vp->v_mount; 902 MNT_ILOCK(mp); 903 flag = mp->mnt_flag; 904 /* 905 * We only allow the filesystem to be reloaded if it 906 * is currently mounted read-only. 907 */ 908 if ((fsflags & MNT_RELOAD) && 909 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 910 MNT_IUNLOCK(mp); 911 vput(vp); 912 return (EOPNOTSUPP); /* Needs translation */ 913 } 914 MNT_IUNLOCK(mp); 915 /* 916 * Only privileged root, or (if MNT_USER is set) the user that 917 * did the original mount is permitted to update it. 918 */ 919 error = vfs_suser(mp, td); 920 if (error) { 921 vput(vp); 922 return (error); 923 } 924 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 925 vput(vp); 926 return (EBUSY); 927 } 928 VI_LOCK(vp); 929 if ((vp->v_iflag & VI_MOUNT) != 0 || 930 vp->v_mountedhere != NULL) { 931 VI_UNLOCK(vp); 932 vfs_unbusy(mp, td); 933 vput(vp); 934 return (EBUSY); 935 } 936 vp->v_iflag |= VI_MOUNT; 937 VI_UNLOCK(vp); 938 MNT_ILOCK(mp); 939 mp->mnt_flag |= fsflags & 940 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 941 MNT_IUNLOCK(mp); 942 VOP_UNLOCK(vp, 0); 943 mp->mnt_optnew = fsdata; 944 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 945 } else { 946 /* 947 * If the user is not root, ensure that they own the directory 948 * onto which we are attempting to mount. 949 */ 950 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 951 if (error) { 952 vput(vp); 953 return (error); 954 } 955 if (va.va_uid != td->td_ucred->cr_uid) { 956 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 957 0); 958 if (error) { 959 vput(vp); 960 return (error); 961 } 962 } 963 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 964 if (error != 0) { 965 vput(vp); 966 return (error); 967 } 968 if (vp->v_type != VDIR) { 969 vput(vp); 970 return (ENOTDIR); 971 } 972 VI_LOCK(vp); 973 if ((vp->v_iflag & VI_MOUNT) != 0 || 974 vp->v_mountedhere != NULL) { 975 VI_UNLOCK(vp); 976 vput(vp); 977 return (EBUSY); 978 } 979 vp->v_iflag |= VI_MOUNT; 980 VI_UNLOCK(vp); 981 982 /* 983 * Allocate and initialize the filesystem. 984 */ 985 mp = vfs_mount_alloc(vp, vfsp, fspath, td); 986 VOP_UNLOCK(vp, 0); 987 988 /* XXXMAC: pass to vfs_mount_alloc? */ 989 mp->mnt_optnew = fsdata; 990 } 991 992 /* 993 * Set the mount level flags. 994 */ 995 MNT_ILOCK(mp); 996 mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) | 997 (fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS | 998 MNT_RDONLY)); 999 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1000 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1001 MNT_IUNLOCK(mp); 1002 /* 1003 * Mount the filesystem. 1004 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1005 * get. No freeing of cn_pnbuf. 1006 */ 1007 error = VFS_MOUNT(mp, td); 1008 1009 /* 1010 * Process the export option only if we are 1011 * updating mount options. 1012 */ 1013 if (!error && (fsflags & MNT_UPDATE)) { 1014 if (vfs_copyopt(mp->mnt_optnew, "export", &export, 1015 sizeof(export)) == 0) 1016 error = vfs_export(mp, &export); 1017 } 1018 1019 if (!error) { 1020 if (mp->mnt_opt != NULL) 1021 vfs_freeopts(mp->mnt_opt); 1022 mp->mnt_opt = mp->mnt_optnew; 1023 (void)VFS_STATFS(mp, &mp->mnt_stat, td); 1024 } 1025 /* 1026 * Prevent external consumers of mount options from reading 1027 * mnt_optnew. 1028 */ 1029 mp->mnt_optnew = NULL; 1030 if (mp->mnt_flag & MNT_UPDATE) { 1031 MNT_ILOCK(mp); 1032 if (error) 1033 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | 1034 (flag & ~MNT_QUOTA); 1035 else 1036 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | 1037 MNT_FORCE | MNT_SNAPSHOT); 1038 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1039 mp->mnt_kern_flag |= MNTK_ASYNC; 1040 else 1041 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1042 MNT_IUNLOCK(mp); 1043 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1044 if (mp->mnt_syncer == NULL) 1045 error = vfs_allocate_syncvnode(mp); 1046 } else { 1047 if (mp->mnt_syncer != NULL) 1048 vrele(mp->mnt_syncer); 1049 mp->mnt_syncer = NULL; 1050 } 1051 vfs_unbusy(mp, td); 1052 VI_LOCK(vp); 1053 vp->v_iflag &= ~VI_MOUNT; 1054 VI_UNLOCK(vp); 1055 vrele(vp); 1056 return (error); 1057 } 1058 MNT_ILOCK(mp); 1059 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1060 mp->mnt_kern_flag |= MNTK_ASYNC; 1061 else 1062 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1063 MNT_IUNLOCK(mp); 1064 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1065 /* 1066 * Put the new filesystem on the mount list after root. 1067 */ 1068 cache_purge(vp); 1069 if (!error) { 1070 struct vnode *newdp; 1071 1072 VI_LOCK(vp); 1073 vp->v_iflag &= ~VI_MOUNT; 1074 VI_UNLOCK(vp); 1075 vp->v_mountedhere = mp; 1076 mtx_lock(&mountlist_mtx); 1077 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1078 mtx_unlock(&mountlist_mtx); 1079 vfs_event_signal(NULL, VQ_MOUNT, 0); 1080 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 1081 panic("mount: lost mount"); 1082 mountcheckdirs(vp, newdp); 1083 vput(newdp); 1084 VOP_UNLOCK(vp, 0); 1085 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1086 error = vfs_allocate_syncvnode(mp); 1087 vfs_unbusy(mp, td); 1088 if (error) 1089 vrele(vp); 1090 } else { 1091 VI_LOCK(vp); 1092 vp->v_iflag &= ~VI_MOUNT; 1093 VI_UNLOCK(vp); 1094 vfs_unbusy(mp, td); 1095 vfs_mount_destroy(mp); 1096 vput(vp); 1097 } 1098 return (error); 1099} 1100 1101/* 1102 * Unmount a filesystem. 1103 * 1104 * Note: unmount takes a path to the vnode mounted on as argument, not 1105 * special file (as before). 1106 */ 1107#ifndef _SYS_SYSPROTO_H_ 1108struct unmount_args { 1109 char *path; 1110 int flags; 1111}; 1112#endif 1113/* ARGSUSED */ 1114int 1115unmount(td, uap) 1116 struct thread *td; 1117 register struct unmount_args /* { 1118 char *path; 1119 int flags; 1120 } */ *uap; 1121{ 1122 struct mount *mp; 1123 char *pathbuf; 1124 int error, id0, id1; 1125 1126 if (jailed(td->td_ucred) || usermount == 0) { 1127 error = priv_check(td, PRIV_VFS_UNMOUNT); 1128 if (error) 1129 return (error); 1130 } 1131 1132 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1133 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1134 if (error) { 1135 free(pathbuf, M_TEMP); 1136 return (error); 1137 } 1138 AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1); 1139 mtx_lock(&Giant); 1140 if (uap->flags & MNT_BYFSID) { 1141 /* Decode the filesystem ID. */ 1142 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1143 mtx_unlock(&Giant); 1144 free(pathbuf, M_TEMP); 1145 return (EINVAL); 1146 } 1147 1148 mtx_lock(&mountlist_mtx); 1149 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1150 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1151 mp->mnt_stat.f_fsid.val[1] == id1) 1152 break; 1153 } 1154 mtx_unlock(&mountlist_mtx); 1155 } else { 1156 mtx_lock(&mountlist_mtx); 1157 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1158 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1159 break; 1160 } 1161 mtx_unlock(&mountlist_mtx); 1162 } 1163 free(pathbuf, M_TEMP); 1164 if (mp == NULL) { 1165 /* 1166 * Previously we returned ENOENT for a nonexistent path and 1167 * EINVAL for a non-mountpoint. We cannot tell these apart 1168 * now, so in the !MNT_BYFSID case return the more likely 1169 * EINVAL for compatibility. 1170 */ 1171 mtx_unlock(&Giant); 1172 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1173 } 1174 1175 /* 1176 * Don't allow unmounting the root filesystem. 1177 */ 1178 if (mp->mnt_flag & MNT_ROOTFS) { 1179 mtx_unlock(&Giant); 1180 return (EINVAL); 1181 } 1182 error = dounmount(mp, uap->flags, td); 1183 mtx_unlock(&Giant); 1184 return (error); 1185} 1186 1187/* 1188 * Do the actual filesystem unmount. 1189 */ 1190int 1191dounmount(mp, flags, td) 1192 struct mount *mp; 1193 int flags; 1194 struct thread *td; 1195{ 1196 struct vnode *coveredvp, *fsrootvp; 1197 int error; 1198 int async_flag; 1199 int mnt_gen_r; 1200 1201 mtx_assert(&Giant, MA_OWNED); 1202 1203 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 1204 mnt_gen_r = mp->mnt_gen; 1205 VI_LOCK(coveredvp); 1206 vholdl(coveredvp); 1207 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY); 1208 vdrop(coveredvp); 1209 /* 1210 * Check for mp being unmounted while waiting for the 1211 * covered vnode lock. 1212 */ 1213 if (coveredvp->v_mountedhere != mp || 1214 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 1215 VOP_UNLOCK(coveredvp, 0); 1216 return (EBUSY); 1217 } 1218 } 1219 /* 1220 * Only privileged root, or (if MNT_USER is set) the user that did the 1221 * original mount is permitted to unmount this filesystem. 1222 */ 1223 error = vfs_suser(mp, td); 1224 if (error) { 1225 if (coveredvp) 1226 VOP_UNLOCK(coveredvp, 0); 1227 return (error); 1228 } 1229 1230 MNT_ILOCK(mp); 1231 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1232 MNT_IUNLOCK(mp); 1233 if (coveredvp) 1234 VOP_UNLOCK(coveredvp, 0); 1235 return (EBUSY); 1236 } 1237 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ; 1238 /* Allow filesystems to detect that a forced unmount is in progress. */ 1239 if (flags & MNT_FORCE) 1240 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1241 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1242 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp)); 1243 if (error) { 1244 MNT_ILOCK(mp); 1245 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_NOINSMNTQ | 1246 MNTK_UNMOUNTF); 1247 if (mp->mnt_kern_flag & MNTK_MWAIT) 1248 wakeup(mp); 1249 MNT_IUNLOCK(mp); 1250 if (coveredvp) 1251 VOP_UNLOCK(coveredvp, 0); 1252 return (error); 1253 } 1254 vn_start_write(NULL, &mp, V_WAIT); 1255 1256 if (mp->mnt_flag & MNT_EXPUBLIC) 1257 vfs_setpublicfs(NULL, NULL, NULL); 1258 1259 vfs_msync(mp, MNT_WAIT); 1260 MNT_ILOCK(mp); 1261 async_flag = mp->mnt_flag & MNT_ASYNC; 1262 mp->mnt_flag &= ~MNT_ASYNC; 1263 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1264 MNT_IUNLOCK(mp); 1265 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1266 if (mp->mnt_syncer != NULL) 1267 vrele(mp->mnt_syncer); 1268 /* 1269 * For forced unmounts, move process cdir/rdir refs on the fs root 1270 * vnode to the covered vnode. For non-forced unmounts we want 1271 * such references to cause an EBUSY error. 1272 */ 1273 if ((flags & MNT_FORCE) && 1274 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1275 if (mp->mnt_vnodecovered != NULL) 1276 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 1277 if (fsrootvp == rootvnode) { 1278 vrele(rootvnode); 1279 rootvnode = NULL; 1280 } 1281 vput(fsrootvp); 1282 } 1283 if (((mp->mnt_flag & MNT_RDONLY) || 1284 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 1285 (flags & MNT_FORCE)) { 1286 error = VFS_UNMOUNT(mp, flags, td); 1287 } 1288 vn_finished_write(mp); 1289 /* 1290 * If we failed to flush the dirty blocks for this mount point, 1291 * undo all the cdir/rdir and rootvnode changes we made above. 1292 * Unless we failed to do so because the device is reporting that 1293 * it doesn't exist anymore. 1294 */ 1295 if (error && error != ENXIO) { 1296 if ((flags & MNT_FORCE) && 1297 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1298 if (mp->mnt_vnodecovered != NULL) 1299 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 1300 if (rootvnode == NULL) { 1301 rootvnode = fsrootvp; 1302 vref(rootvnode); 1303 } 1304 vput(fsrootvp); 1305 } 1306 MNT_ILOCK(mp); 1307 mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ; 1308 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) { 1309 MNT_IUNLOCK(mp); 1310 (void) vfs_allocate_syncvnode(mp); 1311 MNT_ILOCK(mp); 1312 } 1313 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1314 mp->mnt_flag |= async_flag; 1315 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1316 mp->mnt_kern_flag |= MNTK_ASYNC; 1317 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL); 1318 if (mp->mnt_kern_flag & MNTK_MWAIT) 1319 wakeup(mp); 1320 MNT_IUNLOCK(mp); 1321 if (coveredvp) 1322 VOP_UNLOCK(coveredvp, 0); 1323 return (error); 1324 } 1325 mtx_lock(&mountlist_mtx); 1326 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1327 mtx_unlock(&mountlist_mtx); 1328 if (coveredvp != NULL) { 1329 coveredvp->v_mountedhere = NULL; 1330 vput(coveredvp); 1331 } 1332 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1333 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL); 1334 vfs_mount_destroy(mp); 1335 return (0); 1336} 1337 1338/* 1339 * --------------------------------------------------------------------- 1340 * Mounting of root filesystem 1341 * 1342 */ 1343 1344struct root_hold_token { 1345 const char *who; 1346 LIST_ENTRY(root_hold_token) list; 1347}; 1348 1349static LIST_HEAD(, root_hold_token) root_holds = 1350 LIST_HEAD_INITIALIZER(&root_holds); 1351 1352static int root_mount_complete; 1353 1354/* 1355 * Hold root mount. 1356 */ 1357struct root_hold_token * 1358root_mount_hold(const char *identifier) 1359{ 1360 struct root_hold_token *h; 1361 1362 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1363 h->who = identifier; 1364 mtx_lock(&mountlist_mtx); 1365 LIST_INSERT_HEAD(&root_holds, h, list); 1366 mtx_unlock(&mountlist_mtx); 1367 return (h); 1368} 1369 1370/* 1371 * Release root mount. 1372 */ 1373void 1374root_mount_rel(struct root_hold_token *h) 1375{ 1376 1377 mtx_lock(&mountlist_mtx); 1378 LIST_REMOVE(h, list); 1379 wakeup(&root_holds); 1380 mtx_unlock(&mountlist_mtx); 1381 free(h, M_DEVBUF); 1382} 1383 1384/* 1385 * Wait for all subsystems to release root mount. 1386 */ 1387static void 1388root_mount_prepare(void) 1389{ 1390 struct root_hold_token *h; 1391 1392 for (;;) { 1393 DROP_GIANT(); 1394 g_waitidle(); 1395 PICKUP_GIANT(); 1396 mtx_lock(&mountlist_mtx); 1397 if (LIST_EMPTY(&root_holds)) { 1398 mtx_unlock(&mountlist_mtx); 1399 break; 1400 } 1401 printf("Root mount waiting for:"); 1402 LIST_FOREACH(h, &root_holds, list) 1403 printf(" %s", h->who); 1404 printf("\n"); 1405 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1406 hz); 1407 } 1408} 1409 1410/* 1411 * Root was mounted, share the good news. 1412 */ 1413static void 1414root_mount_done(void) 1415{ 1416 1417 /* 1418 * Use a mutex to prevent the wakeup being missed and waiting for 1419 * an extra 1 second sleep. 1420 */ 1421 mtx_lock(&mountlist_mtx); 1422 root_mount_complete = 1; 1423 wakeup(&root_mount_complete); 1424 mtx_unlock(&mountlist_mtx); 1425} 1426 1427/* 1428 * Return true if root is already mounted. 1429 */ 1430int 1431root_mounted(void) 1432{ 1433 1434 /* No mutex is acquired here because int stores are atomic. */ 1435 return (root_mount_complete); 1436} 1437 1438/* 1439 * Wait until root is mounted. 1440 */ 1441void 1442root_mount_wait(void) 1443{ 1444 1445 /* 1446 * Panic on an obvious deadlock - the function can't be called from 1447 * a thread which is doing the whole SYSINIT stuff. 1448 */ 1449 KASSERT(curthread->td_proc->p_pid != 0, 1450 ("root_mount_wait: cannot be called from the swapper thread")); 1451 mtx_lock(&mountlist_mtx); 1452 while (!root_mount_complete) { 1453 msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait", 1454 hz); 1455 } 1456 mtx_unlock(&mountlist_mtx); 1457} 1458 1459static void 1460set_rootvnode(struct thread *td) 1461{ 1462 struct proc *p; 1463 1464 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1465 panic("Cannot find root vnode"); 1466 1467 p = td->td_proc; 1468 FILEDESC_SLOCK(p->p_fd); 1469 1470 if (p->p_fd->fd_cdir != NULL) 1471 vrele(p->p_fd->fd_cdir); 1472 p->p_fd->fd_cdir = rootvnode; 1473 VREF(rootvnode); 1474 1475 if (p->p_fd->fd_rdir != NULL) 1476 vrele(p->p_fd->fd_rdir); 1477 p->p_fd->fd_rdir = rootvnode; 1478 VREF(rootvnode); 1479 1480 FILEDESC_SUNLOCK(p->p_fd); 1481 1482 VOP_UNLOCK(rootvnode, 0); 1483} 1484 1485/* 1486 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1487 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1488 */ 1489 1490static void 1491devfs_first(void) 1492{ 1493 struct thread *td = curthread; 1494 struct vfsoptlist *opts; 1495 struct vfsconf *vfsp; 1496 struct mount *mp = NULL; 1497 int error; 1498 1499 vfsp = vfs_byname("devfs"); 1500 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1501 if (vfsp == NULL) 1502 return; 1503 1504 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td); 1505 1506 error = VFS_MOUNT(mp, td); 1507 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1508 if (error) 1509 return; 1510 1511 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 1512 TAILQ_INIT(opts); 1513 mp->mnt_opt = opts; 1514 1515 mtx_lock(&mountlist_mtx); 1516 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1517 mtx_unlock(&mountlist_mtx); 1518 1519 set_rootvnode(td); 1520 1521 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1522 if (error) 1523 printf("kern_symlink /dev -> / returns %d\n", error); 1524} 1525 1526/* 1527 * Surgically move our devfs to be mounted on /dev. 1528 */ 1529 1530static void 1531devfs_fixup(struct thread *td) 1532{ 1533 struct nameidata nd; 1534 int error; 1535 struct vnode *vp, *dvp; 1536 struct mount *mp; 1537 1538 /* Remove our devfs mount from the mountlist and purge the cache */ 1539 mtx_lock(&mountlist_mtx); 1540 mp = TAILQ_FIRST(&mountlist); 1541 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1542 mtx_unlock(&mountlist_mtx); 1543 cache_purgevfs(mp); 1544 1545 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1546 VI_LOCK(dvp); 1547 dvp->v_iflag &= ~VI_MOUNT; 1548 VI_UNLOCK(dvp); 1549 dvp->v_mountedhere = NULL; 1550 1551 /* Set up the real rootvnode, and purge the cache */ 1552 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1553 set_rootvnode(td); 1554 cache_purgevfs(rootvnode->v_mount); 1555 1556 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1557 error = namei(&nd); 1558 if (error) { 1559 printf("Lookup of /dev for devfs, error: %d\n", error); 1560 return; 1561 } 1562 NDFREE(&nd, NDF_ONLY_PNBUF); 1563 vp = nd.ni_vp; 1564 if (vp->v_type != VDIR) { 1565 vput(vp); 1566 } 1567 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1568 if (error) { 1569 vput(vp); 1570 } 1571 cache_purge(vp); 1572 mp->mnt_vnodecovered = vp; 1573 vp->v_mountedhere = mp; 1574 mtx_lock(&mountlist_mtx); 1575 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1576 mtx_unlock(&mountlist_mtx); 1577 VOP_UNLOCK(vp, 0); 1578 vput(dvp); 1579 vfs_unbusy(mp, td); 1580 1581 /* Unlink the no longer needed /dev/dev -> / symlink */ 1582 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1583} 1584 1585/* 1586 * Report errors during filesystem mounting. 1587 */ 1588void 1589vfs_mount_error(struct mount *mp, const char *fmt, ...) 1590{ 1591 struct vfsoptlist *moptlist = mp->mnt_optnew; 1592 va_list ap; 1593 int error, len; 1594 char *errmsg; 1595 1596 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1597 if (error || errmsg == NULL || len <= 0) 1598 return; 1599 1600 va_start(ap, fmt); 1601 vsnprintf(errmsg, (size_t)len, fmt, ap); 1602 va_end(ap); 1603} 1604 1605/* 1606 * Find and mount the root filesystem 1607 */ 1608void 1609vfs_mountroot(void) 1610{ 1611 char *cp; 1612 int error, i, asked = 0; 1613 1614 root_mount_prepare(); 1615 1616 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), 1617 NULL, NULL, mount_init, mount_fini, 1618 UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1619 devfs_first(); 1620 1621 /* 1622 * We are booted with instructions to prompt for the root filesystem. 1623 */ 1624 if (boothowto & RB_ASKNAME) { 1625 if (!vfs_mountroot_ask()) 1626 goto mounted; 1627 asked = 1; 1628 } 1629 1630 /* 1631 * The root filesystem information is compiled in, and we are 1632 * booted with instructions to use it. 1633 */ 1634 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1635 if (!vfs_mountroot_try(ctrootdevname)) 1636 goto mounted; 1637 ctrootdevname = NULL; 1638 } 1639 1640 /* 1641 * We've been given the generic "use CDROM as root" flag. This is 1642 * necessary because one media may be used in many different 1643 * devices, so we need to search for them. 1644 */ 1645 if (boothowto & RB_CDROM) { 1646 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1647 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1648 goto mounted; 1649 } 1650 } 1651 1652 /* 1653 * Try to use the value read by the loader from /etc/fstab, or 1654 * supplied via some other means. This is the preferred 1655 * mechanism. 1656 */ 1657 cp = getenv("vfs.root.mountfrom"); 1658 if (cp != NULL) { 1659 error = vfs_mountroot_try(cp); 1660 freeenv(cp); 1661 if (!error) 1662 goto mounted; 1663 } 1664 1665 /* 1666 * Try values that may have been computed by code during boot 1667 */ 1668 if (!vfs_mountroot_try(rootdevnames[0])) 1669 goto mounted; 1670 if (!vfs_mountroot_try(rootdevnames[1])) 1671 goto mounted; 1672 1673 /* 1674 * If we (still) have a compiled-in default, try it. 1675 */ 1676 if (ctrootdevname != NULL) 1677 if (!vfs_mountroot_try(ctrootdevname)) 1678 goto mounted; 1679 /* 1680 * Everything so far has failed, prompt on the console if we haven't 1681 * already tried that. 1682 */ 1683 if (!asked) 1684 if (!vfs_mountroot_ask()) 1685 goto mounted; 1686 1687 panic("Root mount failed, startup aborted."); 1688 1689mounted: 1690 root_mount_done(); 1691} 1692 1693/* 1694 * Mount (mountfrom) as the root filesystem. 1695 */ 1696static int 1697vfs_mountroot_try(const char *mountfrom) 1698{ 1699 struct mount *mp; 1700 char *vfsname, *path; 1701 time_t timebase; 1702 int error; 1703 char patt[32]; 1704 1705 vfsname = NULL; 1706 path = NULL; 1707 mp = NULL; 1708 error = EINVAL; 1709 1710 if (mountfrom == NULL) 1711 return (error); /* don't complain */ 1712 printf("Trying to mount root from %s\n", mountfrom); 1713 1714 /* parse vfs name and path */ 1715 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1716 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1717 vfsname[0] = path[0] = 0; 1718 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1719 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1720 goto out; 1721 1722 if (path[0] == '\0') 1723 strcpy(path, ROOTNAME); 1724 1725 error = kernel_vmount( 1726 MNT_ROOTFS, 1727 "fstype", vfsname, 1728 "fspath", "/", 1729 "from", path, 1730 "ro", NULL, 1731 NULL); 1732 if (error == 0) { 1733 /* 1734 * We mount devfs prior to mounting the / FS, so the first 1735 * entry will typically be devfs. 1736 */ 1737 mp = TAILQ_FIRST(&mountlist); 1738 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1739 1740 /* 1741 * Iterate over all currently mounted file systems and use 1742 * the time stamp found to check and/or initialize the RTC. 1743 * Typically devfs has no time stamp and the only other FS 1744 * is the actual / FS. 1745 * Call inittodr() only once and pass it the largest of the 1746 * timestamps we encounter. 1747 */ 1748 timebase = 0; 1749 do { 1750 if (mp->mnt_time > timebase) 1751 timebase = mp->mnt_time; 1752 mp = TAILQ_NEXT(mp, mnt_list); 1753 } while (mp != NULL); 1754 inittodr(timebase); 1755 1756 devfs_fixup(curthread); 1757 } 1758out: 1759 free(path, M_MOUNT); 1760 free(vfsname, M_MOUNT); 1761 return (error); 1762} 1763 1764/* 1765 * --------------------------------------------------------------------- 1766 * Interactive root filesystem selection code. 1767 */ 1768 1769static int 1770vfs_mountroot_ask(void) 1771{ 1772 char name[128]; 1773 1774 for(;;) { 1775 printf("\nManual root filesystem specification:\n"); 1776 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1777#if defined(__amd64__) || defined(__i386__) || defined(__ia64__) 1778 printf(" eg. ufs:da0s1a\n"); 1779#else 1780 printf(" eg. ufs:/dev/da0a\n"); 1781#endif 1782 printf(" ? List valid disk boot devices\n"); 1783 printf(" <empty line> Abort manual input\n"); 1784 printf("\nmountroot> "); 1785 gets(name, sizeof(name), 1); 1786 if (name[0] == '\0') 1787 return (1); 1788 if (name[0] == '?') { 1789 printf("\nList of GEOM managed disk devices:\n "); 1790 g_dev_print(); 1791 continue; 1792 } 1793 if (!vfs_mountroot_try(name)) 1794 return (0); 1795 } 1796} 1797 1798/* 1799 * --------------------------------------------------------------------- 1800 * Functions for querying mount options/arguments from filesystems. 1801 */ 1802 1803/* 1804 * Check that no unknown options are given 1805 */ 1806int 1807vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1808{ 1809 struct vfsopt *opt; 1810 char errmsg[255]; 1811 const char **t, *p, *q; 1812 int ret = 0; 1813 1814 TAILQ_FOREACH(opt, opts, link) { 1815 p = opt->name; 1816 q = NULL; 1817 if (p[0] == 'n' && p[1] == 'o') 1818 q = p + 2; 1819 for(t = global_opts; *t != NULL; t++) { 1820 if (strcmp(*t, p) == 0) 1821 break; 1822 if (q != NULL) { 1823 if (strcmp(*t, q) == 0) 1824 break; 1825 } 1826 } 1827 if (*t != NULL) 1828 continue; 1829 for(t = legal; *t != NULL; t++) { 1830 if (strcmp(*t, p) == 0) 1831 break; 1832 if (q != NULL) { 1833 if (strcmp(*t, q) == 0) 1834 break; 1835 } 1836 } 1837 if (*t != NULL) 1838 continue; 1839 sprintf(errmsg, "mount option <%s> is unknown", p); 1840 printf("%s\n", errmsg); 1841 ret = EINVAL; 1842 } 1843 if (ret != 0) { 1844 TAILQ_FOREACH(opt, opts, link) { 1845 if (strcmp(opt->name, "errmsg") == 0) { 1846 strncpy((char *)opt->value, errmsg, opt->len); 1847 } 1848 } 1849 } 1850 return (ret); 1851} 1852 1853/* 1854 * Get a mount option by its name. 1855 * 1856 * Return 0 if the option was found, ENOENT otherwise. 1857 * If len is non-NULL it will be filled with the length 1858 * of the option. If buf is non-NULL, it will be filled 1859 * with the address of the option. 1860 */ 1861int 1862vfs_getopt(opts, name, buf, len) 1863 struct vfsoptlist *opts; 1864 const char *name; 1865 void **buf; 1866 int *len; 1867{ 1868 struct vfsopt *opt; 1869 1870 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1871 1872 TAILQ_FOREACH(opt, opts, link) { 1873 if (strcmp(name, opt->name) == 0) { 1874 if (len != NULL) 1875 *len = opt->len; 1876 if (buf != NULL) 1877 *buf = opt->value; 1878 return (0); 1879 } 1880 } 1881 return (ENOENT); 1882} 1883 1884static int 1885vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1886{ 1887 struct vfsopt *opt; 1888 int i; 1889 1890 if (opts == NULL) 1891 return (-1); 1892 1893 i = 0; 1894 TAILQ_FOREACH(opt, opts, link) { 1895 if (strcmp(name, opt->name) == 0) 1896 return (i); 1897 ++i; 1898 } 1899 return (-1); 1900} 1901 1902char * 1903vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1904{ 1905 struct vfsopt *opt; 1906 1907 *error = 0; 1908 TAILQ_FOREACH(opt, opts, link) { 1909 if (strcmp(name, opt->name) != 0) 1910 continue; 1911 if (((char *)opt->value)[opt->len - 1] != '\0') { 1912 *error = EINVAL; 1913 return (NULL); 1914 } 1915 return (opt->value); 1916 } 1917 *error = ENOENT; 1918 return (NULL); 1919} 1920 1921int 1922vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1923{ 1924 struct vfsopt *opt; 1925 1926 TAILQ_FOREACH(opt, opts, link) { 1927 if (strcmp(name, opt->name) == 0) { 1928 if (w != NULL) 1929 *w |= val; 1930 return (1); 1931 } 1932 } 1933 if (w != NULL) 1934 *w &= ~val; 1935 return (0); 1936} 1937 1938int 1939vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1940{ 1941 va_list ap; 1942 struct vfsopt *opt; 1943 int ret; 1944 1945 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1946 1947 TAILQ_FOREACH(opt, opts, link) { 1948 if (strcmp(name, opt->name) != 0) 1949 continue; 1950 if (opt->len == 0 || opt->value == NULL) 1951 return (0); 1952 if (((char *)opt->value)[opt->len - 1] != '\0') 1953 return (0); 1954 va_start(ap, fmt); 1955 ret = vsscanf(opt->value, fmt, ap); 1956 va_end(ap); 1957 return (ret); 1958 } 1959 return (0); 1960} 1961 1962/* 1963 * Find and copy a mount option. 1964 * 1965 * The size of the buffer has to be specified 1966 * in len, if it is not the same length as the 1967 * mount option, EINVAL is returned. 1968 * Returns ENOENT if the option is not found. 1969 */ 1970int 1971vfs_copyopt(opts, name, dest, len) 1972 struct vfsoptlist *opts; 1973 const char *name; 1974 void *dest; 1975 int len; 1976{ 1977 struct vfsopt *opt; 1978 1979 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1980 1981 TAILQ_FOREACH(opt, opts, link) { 1982 if (strcmp(name, opt->name) == 0) { 1983 if (len != opt->len) 1984 return (EINVAL); 1985 bcopy(opt->value, dest, opt->len); 1986 return (0); 1987 } 1988 } 1989 return (ENOENT); 1990} 1991 1992/* 1993 * This is a helper function for filesystems to traverse their 1994 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1995 */ 1996 1997struct vnode * 1998__mnt_vnode_next(struct vnode **mvp, struct mount *mp) 1999{ 2000 struct vnode *vp; 2001 2002 mtx_assert(MNT_MTX(mp), MA_OWNED); 2003 2004 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 2005 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 2006 while (vp != NULL && vp->v_type == VMARKER) 2007 vp = TAILQ_NEXT(vp, v_nmntvnodes); 2008 2009 /* Check if we are done */ 2010 if (vp == NULL) { 2011 __mnt_vnode_markerfree(mvp, mp); 2012 return (NULL); 2013 } 2014 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 2015 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 2016 return (vp); 2017} 2018 2019struct vnode * 2020__mnt_vnode_first(struct vnode **mvp, struct mount *mp) 2021{ 2022 struct vnode *vp; 2023 2024 mtx_assert(MNT_MTX(mp), MA_OWNED); 2025 2026 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2027 while (vp != NULL && vp->v_type == VMARKER) 2028 vp = TAILQ_NEXT(vp, v_nmntvnodes); 2029 2030 /* Check if we are done */ 2031 if (vp == NULL) { 2032 *mvp = NULL; 2033 return (NULL); 2034 } 2035 mp->mnt_holdcnt++; 2036 MNT_IUNLOCK(mp); 2037 *mvp = (struct vnode *) malloc(sizeof(struct vnode), 2038 M_VNODE_MARKER, 2039 M_WAITOK | M_ZERO); 2040 MNT_ILOCK(mp); 2041 (*mvp)->v_type = VMARKER; 2042 2043 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2044 while (vp != NULL && vp->v_type == VMARKER) 2045 vp = TAILQ_NEXT(vp, v_nmntvnodes); 2046 2047 /* Check if we are done */ 2048 if (vp == NULL) { 2049 MNT_IUNLOCK(mp); 2050 free(*mvp, M_VNODE_MARKER); 2051 MNT_ILOCK(mp); 2052 *mvp = NULL; 2053 mp->mnt_holdcnt--; 2054 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 2055 wakeup(&mp->mnt_holdcnt); 2056 return (NULL); 2057 } 2058 mp->mnt_markercnt++; 2059 (*mvp)->v_mount = mp; 2060 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 2061 return (vp); 2062} 2063 2064 2065void 2066__mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp) 2067{ 2068 2069 if (*mvp == NULL) 2070 return; 2071 2072 mtx_assert(MNT_MTX(mp), MA_OWNED); 2073 2074 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 2075 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 2076 MNT_IUNLOCK(mp); 2077 free(*mvp, M_VNODE_MARKER); 2078 MNT_ILOCK(mp); 2079 *mvp = NULL; 2080 2081 mp->mnt_markercnt--; 2082 mp->mnt_holdcnt--; 2083 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 2084 wakeup(&mp->mnt_holdcnt); 2085} 2086 2087 2088int 2089__vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 2090{ 2091 int error; 2092 2093 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 2094 if (sbp != &mp->mnt_stat) 2095 *sbp = mp->mnt_stat; 2096 return (error); 2097} 2098 2099void 2100vfs_mountedfrom(struct mount *mp, const char *from) 2101{ 2102 2103 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2104 strlcpy(mp->mnt_stat.f_mntfromname, from, 2105 sizeof mp->mnt_stat.f_mntfromname); 2106} 2107 2108/* 2109 * --------------------------------------------------------------------- 2110 * This is the api for building mount args and mounting filesystems from 2111 * inside the kernel. 2112 * 2113 * The API works by accumulation of individual args. First error is 2114 * latched. 2115 * 2116 * XXX: should be documented in new manpage kernel_mount(9) 2117 */ 2118 2119/* A memory allocation which must be freed when we are done */ 2120struct mntaarg { 2121 SLIST_ENTRY(mntaarg) next; 2122}; 2123 2124/* The header for the mount arguments */ 2125struct mntarg { 2126 struct iovec *v; 2127 int len; 2128 int error; 2129 SLIST_HEAD(, mntaarg) list; 2130}; 2131 2132/* 2133 * Add a boolean argument. 2134 * 2135 * flag is the boolean value. 2136 * name must start with "no". 2137 */ 2138struct mntarg * 2139mount_argb(struct mntarg *ma, int flag, const char *name) 2140{ 2141 2142 KASSERT(name[0] == 'n' && name[1] == 'o', 2143 ("mount_argb(...,%s): name must start with 'no'", name)); 2144 2145 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2146} 2147 2148/* 2149 * Add an argument printf style 2150 */ 2151struct mntarg * 2152mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2153{ 2154 va_list ap; 2155 struct mntaarg *maa; 2156 struct sbuf *sb; 2157 int len; 2158 2159 if (ma == NULL) { 2160 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2161 SLIST_INIT(&ma->list); 2162 } 2163 if (ma->error) 2164 return (ma); 2165 2166 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2167 M_MOUNT, M_WAITOK); 2168 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2169 ma->v[ma->len].iov_len = strlen(name) + 1; 2170 ma->len++; 2171 2172 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 2173 va_start(ap, fmt); 2174 sbuf_vprintf(sb, fmt, ap); 2175 va_end(ap); 2176 sbuf_finish(sb); 2177 len = sbuf_len(sb) + 1; 2178 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2179 SLIST_INSERT_HEAD(&ma->list, maa, next); 2180 bcopy(sbuf_data(sb), maa + 1, len); 2181 sbuf_delete(sb); 2182 2183 ma->v[ma->len].iov_base = maa + 1; 2184 ma->v[ma->len].iov_len = len; 2185 ma->len++; 2186 2187 return (ma); 2188} 2189 2190/* 2191 * Add an argument which is a userland string. 2192 */ 2193struct mntarg * 2194mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2195{ 2196 struct mntaarg *maa; 2197 char *tbuf; 2198 2199 if (val == NULL) 2200 return (ma); 2201 if (ma == NULL) { 2202 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2203 SLIST_INIT(&ma->list); 2204 } 2205 if (ma->error) 2206 return (ma); 2207 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2208 SLIST_INSERT_HEAD(&ma->list, maa, next); 2209 tbuf = (void *)(maa + 1); 2210 ma->error = copyinstr(val, tbuf, len, NULL); 2211 return (mount_arg(ma, name, tbuf, -1)); 2212} 2213 2214/* 2215 * Plain argument. 2216 * 2217 * If length is -1, treat value as a C string. 2218 */ 2219struct mntarg * 2220mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2221{ 2222 2223 if (ma == NULL) { 2224 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2225 SLIST_INIT(&ma->list); 2226 } 2227 if (ma->error) 2228 return (ma); 2229 2230 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2231 M_MOUNT, M_WAITOK); 2232 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2233 ma->v[ma->len].iov_len = strlen(name) + 1; 2234 ma->len++; 2235 2236 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2237 if (len < 0) 2238 ma->v[ma->len].iov_len = strlen(val) + 1; 2239 else 2240 ma->v[ma->len].iov_len = len; 2241 ma->len++; 2242 return (ma); 2243} 2244 2245/* 2246 * Free a mntarg structure 2247 */ 2248static void 2249free_mntarg(struct mntarg *ma) 2250{ 2251 struct mntaarg *maa; 2252 2253 while (!SLIST_EMPTY(&ma->list)) { 2254 maa = SLIST_FIRST(&ma->list); 2255 SLIST_REMOVE_HEAD(&ma->list, next); 2256 free(maa, M_MOUNT); 2257 } 2258 free(ma->v, M_MOUNT); 2259 free(ma, M_MOUNT); 2260} 2261 2262/* 2263 * Mount a filesystem 2264 */ 2265int 2266kernel_mount(struct mntarg *ma, int flags) 2267{ 2268 struct uio auio; 2269 int error; 2270 2271 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2272 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2273 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2274 2275 auio.uio_iov = ma->v; 2276 auio.uio_iovcnt = ma->len; 2277 auio.uio_segflg = UIO_SYSSPACE; 2278 2279 error = ma->error; 2280 if (!error) 2281 error = vfs_donmount(curthread, flags, &auio); 2282 free_mntarg(ma); 2283 return (error); 2284} 2285 2286/* 2287 * A printflike function to mount a filesystem. 2288 */ 2289int 2290kernel_vmount(int flags, ...) 2291{ 2292 struct mntarg *ma = NULL; 2293 va_list ap; 2294 const char *cp; 2295 const void *vp; 2296 int error; 2297 2298 va_start(ap, flags); 2299 for (;;) { 2300 cp = va_arg(ap, const char *); 2301 if (cp == NULL) 2302 break; 2303 vp = va_arg(ap, const void *); 2304 ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0)); 2305 } 2306 va_end(ap); 2307 2308 error = kernel_mount(ma, flags); 2309 return (error); 2310} 2311