vfs_mount.c revision 168823
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 168823 2007-04-17 21:14:06Z pjd $"); 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 "rdonly", 138 "ro", 139 "rw", 140 "suid", 141 "exec", 142 "update", 143 NULL 144}; 145 146/* 147 * The root specifiers we will try if RB_CDROM is specified. 148 */ 149static char *cdrom_rootdevnames[] = { 150 "cd9660:cd0", 151 "cd9660:acd0", 152 NULL 153}; 154 155/* legacy find-root code */ 156char *rootdevnames[2] = {NULL, NULL}; 157#ifndef ROOTDEVNAME 158# define ROOTDEVNAME NULL 159#endif 160static const char *ctrootdevname = ROOTDEVNAME; 161 162/* 163 * --------------------------------------------------------------------- 164 * Functions for building and sanitizing the mount options 165 */ 166 167/* Remove one mount option. */ 168static void 169vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 170{ 171 172 TAILQ_REMOVE(opts, opt, link); 173 free(opt->name, M_MOUNT); 174 if (opt->value != NULL) 175 free(opt->value, M_MOUNT); 176#ifdef INVARIANTS 177 else if (opt->len != 0) 178 panic("%s: mount option with NULL value but length != 0", 179 __func__); 180#endif 181 free(opt, M_MOUNT); 182} 183 184/* Release all resources related to the mount options. */ 185void 186vfs_freeopts(struct vfsoptlist *opts) 187{ 188 struct vfsopt *opt; 189 190 while (!TAILQ_EMPTY(opts)) { 191 opt = TAILQ_FIRST(opts); 192 vfs_freeopt(opts, opt); 193 } 194 free(opts, M_MOUNT); 195} 196 197void 198vfs_deleteopt(struct vfsoptlist *opts, const char *name) 199{ 200 struct vfsopt *opt, *temp; 201 202 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 203 if (strcmp(opt->name, name) == 0) 204 vfs_freeopt(opts, opt); 205 } 206} 207 208/* 209 * Check if options are equal (with or without the "no" prefix). 210 */ 211static int 212vfs_equalopts(const char *opt1, const char *opt2) 213{ 214 215 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 216 if (strcmp(opt1, opt2) == 0) 217 return (1); 218 /* "noopt" vs. "opt" */ 219 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 220 return (1); 221 /* "opt" vs. "noopt" */ 222 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 223 return (1); 224 return (0); 225} 226 227/* 228 * If a mount option is specified several times, 229 * (with or without the "no" prefix) only keep 230 * the last occurence of it. 231 */ 232static void 233vfs_sanitizeopts(struct vfsoptlist *opts) 234{ 235 struct vfsopt *opt, *opt2, *tmp; 236 237 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 238 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 239 while (opt2 != NULL) { 240 if (vfs_equalopts(opt->name, opt2->name)) { 241 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 242 vfs_freeopt(opts, opt2); 243 opt2 = tmp; 244 } else { 245 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 246 } 247 } 248 } 249} 250 251/* 252 * Build a linked list of mount options from a struct uio. 253 */ 254static int 255vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 256{ 257 struct vfsoptlist *opts; 258 struct vfsopt *opt; 259 size_t memused; 260 unsigned int i, iovcnt; 261 int error, namelen, optlen; 262 263 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 264 TAILQ_INIT(opts); 265 memused = 0; 266 iovcnt = auio->uio_iovcnt; 267 for (i = 0; i < iovcnt; i += 2) { 268 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 269 namelen = auio->uio_iov[i].iov_len; 270 optlen = auio->uio_iov[i + 1].iov_len; 271 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 272 opt->value = NULL; 273 opt->len = 0; 274 275 /* 276 * Do this early, so jumps to "bad" will free the current 277 * option. 278 */ 279 TAILQ_INSERT_TAIL(opts, opt, link); 280 memused += sizeof(struct vfsopt) + optlen + namelen; 281 282 /* 283 * Avoid consuming too much memory, and attempts to overflow 284 * memused. 285 */ 286 if (memused > VFS_MOUNTARG_SIZE_MAX || 287 optlen > VFS_MOUNTARG_SIZE_MAX || 288 namelen > VFS_MOUNTARG_SIZE_MAX) { 289 error = EINVAL; 290 goto bad; 291 } 292 293 if (auio->uio_segflg == UIO_SYSSPACE) { 294 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 295 } else { 296 error = copyin(auio->uio_iov[i].iov_base, opt->name, 297 namelen); 298 if (error) 299 goto bad; 300 } 301 /* Ensure names are null-terminated strings. */ 302 if (opt->name[namelen - 1] != '\0') { 303 error = EINVAL; 304 goto bad; 305 } 306 if (optlen != 0) { 307 opt->len = optlen; 308 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 309 if (auio->uio_segflg == UIO_SYSSPACE) { 310 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 311 optlen); 312 } else { 313 error = copyin(auio->uio_iov[i + 1].iov_base, 314 opt->value, optlen); 315 if (error) 316 goto bad; 317 } 318 } 319 } 320 vfs_sanitizeopts(opts); 321 *options = opts; 322 return (0); 323bad: 324 vfs_freeopts(opts); 325 return (error); 326} 327 328/* 329 * Merge the old mount options with the new ones passed 330 * in the MNT_UPDATE case. 331 */ 332static void 333vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 334{ 335 struct vfsopt *opt, *opt2, *new; 336 337 TAILQ_FOREACH(opt, opts, link) { 338 /* 339 * Check that this option hasn't been redefined 340 * nor cancelled with a "no" mount option. 341 */ 342 opt2 = TAILQ_FIRST(toopts); 343 while (opt2 != NULL) { 344 if (strcmp(opt2->name, opt->name) == 0) 345 goto next; 346 if (strncmp(opt2->name, "no", 2) == 0 && 347 strcmp(opt2->name + 2, opt->name) == 0) { 348 vfs_freeopt(toopts, opt2); 349 goto next; 350 } 351 opt2 = TAILQ_NEXT(opt2, link); 352 } 353 /* We want this option, duplicate it. */ 354 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 355 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 356 strcpy(new->name, opt->name); 357 if (opt->len != 0) { 358 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 359 bcopy(opt->value, new->value, opt->len); 360 } else { 361 new->value = NULL; 362 } 363 new->len = opt->len; 364 TAILQ_INSERT_TAIL(toopts, new, link); 365next: 366 continue; 367 } 368} 369 370/* 371 * Mount a filesystem. 372 */ 373int 374nmount(td, uap) 375 struct thread *td; 376 struct nmount_args /* { 377 struct iovec *iovp; 378 unsigned int iovcnt; 379 int flags; 380 } */ *uap; 381{ 382 struct uio *auio; 383 struct iovec *iov; 384 unsigned int i; 385 int error; 386 u_int iovcnt; 387 388 AUDIT_ARG(fflags, uap->flags); 389 390 /* Kick out MNT_ROOTFS early as it is legal internally */ 391 if (uap->flags & MNT_ROOTFS) 392 return (EINVAL); 393 394 iovcnt = uap->iovcnt; 395 /* 396 * Check that we have an even number of iovec's 397 * and that we have at least two options. 398 */ 399 if ((iovcnt & 1) || (iovcnt < 4)) 400 return (EINVAL); 401 402 error = copyinuio(uap->iovp, iovcnt, &auio); 403 if (error) 404 return (error); 405 iov = auio->uio_iov; 406 for (i = 0; i < iovcnt; i++) { 407 if (iov->iov_len > MMAXOPTIONLEN) { 408 free(auio, M_IOV); 409 return (EINVAL); 410 } 411 iov++; 412 } 413 error = vfs_donmount(td, uap->flags, auio); 414 415 free(auio, M_IOV); 416 return (error); 417} 418 419/* 420 * --------------------------------------------------------------------- 421 * Various utility functions 422 */ 423 424void 425vfs_ref(struct mount *mp) 426{ 427 428 MNT_ILOCK(mp); 429 MNT_REF(mp); 430 MNT_IUNLOCK(mp); 431} 432 433void 434vfs_rel(struct mount *mp) 435{ 436 437 MNT_ILOCK(mp); 438 MNT_REL(mp); 439 MNT_IUNLOCK(mp); 440} 441 442static int 443mount_init(void *mem, int size, int flags) 444{ 445 struct mount *mp; 446 447 mp = (struct mount *)mem; 448 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 449 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 450 return (0); 451} 452 453static void 454mount_fini(void *mem, int size) 455{ 456 struct mount *mp; 457 458 mp = (struct mount *)mem; 459 lockdestroy(&mp->mnt_lock); 460 mtx_destroy(&mp->mnt_mtx); 461} 462 463/* 464 * Allocate and initialize the mount point struct. 465 */ 466struct mount * 467vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 468 const char *fspath, struct thread *td) 469{ 470 struct mount *mp; 471 472 mp = uma_zalloc(mount_zone, M_WAITOK); 473 bzero(&mp->mnt_startzero, 474 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 475 TAILQ_INIT(&mp->mnt_nvnodelist); 476 mp->mnt_nvnodelistsize = 0; 477 mp->mnt_ref = 0; 478 (void) vfs_busy(mp, LK_NOWAIT, 0, td); 479 mp->mnt_op = vfsp->vfc_vfsops; 480 mp->mnt_vfc = vfsp; 481 vfsp->vfc_refcount++; /* XXX Unlocked */ 482 mp->mnt_stat.f_type = vfsp->vfc_typenum; 483 mp->mnt_gen++; 484 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 485 mp->mnt_vnodecovered = vp; 486 mp->mnt_cred = crdup(td->td_ucred); 487 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 488 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 489 mp->mnt_iosize_max = DFLTPHYS; 490#ifdef MAC 491 mac_init_mount(mp); 492 mac_create_mount(td->td_ucred, mp); 493#endif 494 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 495 return (mp); 496} 497 498/* 499 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 500 */ 501void 502vfs_mount_destroy(struct mount *mp) 503{ 504 int i; 505 506 MNT_ILOCK(mp); 507 for (i = 0; mp->mnt_ref && i < 3; i++) 508 msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz); 509 /* 510 * This will always cause a 3 second delay in rebooting due to 511 * refs on the root mountpoint that never go away. Most of these 512 * are held by init which never exits. 513 */ 514 if (i == 3 && (!rebooting || bootverbose)) 515 printf("Mount point %s had %d dangling refs\n", 516 mp->mnt_stat.f_mntonname, mp->mnt_ref); 517 if (mp->mnt_holdcnt != 0) { 518 printf("Waiting for mount point to be unheld\n"); 519 while (mp->mnt_holdcnt != 0) { 520 mp->mnt_holdcntwaiters++; 521 msleep(&mp->mnt_holdcnt, MNT_MTX(mp), 522 PZERO, "mntdestroy", 0); 523 mp->mnt_holdcntwaiters--; 524 } 525 printf("mount point unheld\n"); 526 } 527 if (mp->mnt_writeopcount > 0) { 528 printf("Waiting for mount point write ops\n"); 529 while (mp->mnt_writeopcount > 0) { 530 mp->mnt_kern_flag |= MNTK_SUSPEND; 531 msleep(&mp->mnt_writeopcount, 532 MNT_MTX(mp), 533 PZERO, "mntdestroy2", 0); 534 } 535 printf("mount point write ops completed\n"); 536 } 537 if (mp->mnt_secondary_writes > 0) { 538 printf("Waiting for mount point secondary write ops\n"); 539 while (mp->mnt_secondary_writes > 0) { 540 mp->mnt_kern_flag |= MNTK_SUSPEND; 541 msleep(&mp->mnt_secondary_writes, 542 MNT_MTX(mp), 543 PZERO, "mntdestroy3", 0); 544 } 545 printf("mount point secondary write ops completed\n"); 546 } 547 MNT_IUNLOCK(mp); 548 mp->mnt_vfc->vfc_refcount--; 549 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 550 struct vnode *vp; 551 552 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 553 vprint("", vp); 554 panic("unmount: dangling vnode"); 555 } 556 MNT_ILOCK(mp); 557 if (mp->mnt_kern_flag & MNTK_MWAIT) 558 wakeup(mp); 559 if (mp->mnt_writeopcount != 0) 560 panic("vfs_mount_destroy: nonzero writeopcount"); 561 if (mp->mnt_secondary_writes != 0) 562 panic("vfs_mount_destroy: nonzero secondary_writes"); 563 if (mp->mnt_nvnodelistsize != 0) 564 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 565 mp->mnt_writeopcount = -1000; 566 mp->mnt_nvnodelistsize = -1000; 567 mp->mnt_secondary_writes = -1000; 568 MNT_IUNLOCK(mp); 569#ifdef MAC 570 mac_destroy_mount(mp); 571#endif 572 if (mp->mnt_opt != NULL) 573 vfs_freeopts(mp->mnt_opt); 574 crfree(mp->mnt_cred); 575 uma_zfree(mount_zone, mp); 576} 577 578static int 579vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 580{ 581 struct vfsoptlist *optlist; 582 struct vfsopt *opt, *noro_opt; 583 char *fstype, *fspath, *errmsg; 584 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 585 int has_rw, has_noro; 586 587 errmsg = NULL; 588 errmsg_len = 0; 589 errmsg_pos = -1; 590 has_rw = 0; 591 has_noro = 0; 592 593 error = vfs_buildopts(fsoptions, &optlist); 594 if (error) 595 return (error); 596 597 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 598 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 599 600 /* 601 * We need these two options before the others, 602 * and they are mandatory for any filesystem. 603 * Ensure they are NUL terminated as well. 604 */ 605 fstypelen = 0; 606 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 607 if (error || fstype[fstypelen - 1] != '\0') { 608 error = EINVAL; 609 if (errmsg != NULL) 610 strncpy(errmsg, "Invalid fstype", errmsg_len); 611 goto bail; 612 } 613 fspathlen = 0; 614 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 615 if (error || fspath[fspathlen - 1] != '\0') { 616 error = EINVAL; 617 if (errmsg != NULL) 618 strncpy(errmsg, "Invalid fspath", errmsg_len); 619 goto bail; 620 } 621 622 /* 623 * We need to see if we have the "update" option 624 * before we call vfs_domount(), since vfs_domount() has special 625 * logic based on MNT_UPDATE. This is very important 626 * when we want to update the root filesystem. 627 */ 628 TAILQ_FOREACH(opt, optlist, link) { 629 if (strcmp(opt->name, "update") == 0) 630 fsflags |= MNT_UPDATE; 631 else if (strcmp(opt->name, "async") == 0) 632 fsflags |= MNT_ASYNC; 633 else if (strcmp(opt->name, "force") == 0) 634 fsflags |= MNT_FORCE; 635 else if (strcmp(opt->name, "multilabel") == 0) 636 fsflags |= MNT_MULTILABEL; 637 else if (strcmp(opt->name, "noasync") == 0) 638 fsflags &= ~MNT_ASYNC; 639 else if (strcmp(opt->name, "noatime") == 0) 640 fsflags |= MNT_NOATIME; 641 else if (strcmp(opt->name, "noclusterr") == 0) 642 fsflags |= MNT_NOCLUSTERR; 643 else if (strcmp(opt->name, "noclusterw") == 0) 644 fsflags |= MNT_NOCLUSTERW; 645 else if (strcmp(opt->name, "noexec") == 0) 646 fsflags |= MNT_NOEXEC; 647 else if (strcmp(opt->name, "nosuid") == 0) 648 fsflags |= MNT_NOSUID; 649 else if (strcmp(opt->name, "nosymfollow") == 0) 650 fsflags |= MNT_NOSYMFOLLOW; 651 else if (strcmp(opt->name, "noro") == 0) { 652 fsflags &= ~MNT_RDONLY; 653 has_noro = 1; 654 } 655 else if (strcmp(opt->name, "rw") == 0) { 656 fsflags &= ~MNT_RDONLY; 657 has_rw = 1; 658 } 659 else if (strcmp(opt->name, "ro") == 0 || 660 strcmp(opt->name, "rdonly") == 0) 661 fsflags |= MNT_RDONLY; 662 else if (strcmp(opt->name, "snapshot") == 0) 663 fsflags |= MNT_SNAPSHOT; 664 else if (strcmp(opt->name, "suiddir") == 0) 665 fsflags |= MNT_SUIDDIR; 666 else if (strcmp(opt->name, "sync") == 0) 667 fsflags |= MNT_SYNCHRONOUS; 668 else if (strcmp(opt->name, "union") == 0) 669 fsflags |= MNT_UNION; 670 } 671 672 /* 673 * If "rw" was specified as a mount option, and we 674 * are trying to update a mount-point from "ro" to "rw", 675 * we need a mount option "noro", since in vfs_mergeopts(), 676 * "noro" will cancel "ro", but "rw" will not do anything. 677 */ 678 if (has_rw && !has_noro) { 679 noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 680 noro_opt->name = strdup("noro", M_MOUNT); 681 noro_opt->value = NULL; 682 noro_opt->len = 0; 683 TAILQ_INSERT_TAIL(optlist, noro_opt, link); 684 } 685 686 /* 687 * Be ultra-paranoid about making sure the type and fspath 688 * variables will fit in our mp buffers, including the 689 * terminating NUL. 690 */ 691 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 692 error = ENAMETOOLONG; 693 goto bail; 694 } 695 696 mtx_lock(&Giant); 697 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 698 mtx_unlock(&Giant); 699bail: 700 /* copyout the errmsg */ 701 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 702 && errmsg_len > 0 && errmsg != NULL) { 703 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 704 bcopy(errmsg, 705 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 706 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 707 } else { 708 copyout(errmsg, 709 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 710 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 711 } 712 } 713 714 if (error != 0) 715 vfs_freeopts(optlist); 716 return (error); 717} 718 719/* 720 * Old mount API. 721 */ 722#ifndef _SYS_SYSPROTO_H_ 723struct mount_args { 724 char *type; 725 char *path; 726 int flags; 727 caddr_t data; 728}; 729#endif 730/* ARGSUSED */ 731int 732mount(td, uap) 733 struct thread *td; 734 struct mount_args /* { 735 char *type; 736 char *path; 737 int flags; 738 caddr_t data; 739 } */ *uap; 740{ 741 char *fstype; 742 struct vfsconf *vfsp = NULL; 743 struct mntarg *ma = NULL; 744 int error; 745 746 AUDIT_ARG(fflags, uap->flags); 747 748 /* Kick out MNT_ROOTFS early as it is legal internally */ 749 uap->flags &= ~MNT_ROOTFS; 750 751 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 752 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 753 if (error) { 754 free(fstype, M_TEMP); 755 return (error); 756 } 757 758 AUDIT_ARG(text, fstype); 759 mtx_lock(&Giant); 760 vfsp = vfs_byname_kld(fstype, td, &error); 761 free(fstype, M_TEMP); 762 if (vfsp == NULL) { 763 mtx_unlock(&Giant); 764 return (ENOENT); 765 } 766 if (vfsp->vfc_vfsops->vfs_cmount == NULL) { 767 mtx_unlock(&Giant); 768 return (EOPNOTSUPP); 769 } 770 771 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 772 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 773 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 774 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 775 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 776 777 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 778 mtx_unlock(&Giant); 779 return (error); 780} 781 782 783/* 784 * vfs_domount(): actually attempt a filesystem mount. 785 */ 786static int 787vfs_domount( 788 struct thread *td, /* Calling thread. */ 789 const char *fstype, /* Filesystem type. */ 790 char *fspath, /* Mount path. */ 791 int fsflags, /* Flags common to all filesystems. */ 792 void *fsdata /* Options local to the filesystem. */ 793 ) 794{ 795 struct vnode *vp; 796 struct mount *mp; 797 struct vfsconf *vfsp; 798 struct export_args export; 799 int error, flag = 0; 800 struct vattr va; 801 struct nameidata nd; 802 803 mtx_assert(&Giant, MA_OWNED); 804 /* 805 * Be ultra-paranoid about making sure the type and fspath 806 * variables will fit in our mp buffers, including the 807 * terminating NUL. 808 */ 809 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 810 return (ENAMETOOLONG); 811 812 if (jailed(td->td_ucred) || usermount == 0) { 813 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 814 return (error); 815 } 816 817 /* 818 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 819 */ 820 if (fsflags & MNT_EXPORTED) { 821 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 822 if (error) 823 return (error); 824 } 825 if (fsflags & MNT_SUIDDIR) { 826 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 827 if (error) 828 return (error); 829 } 830 /* 831 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 832 */ 833 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 834 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 835 fsflags |= MNT_NOSUID | MNT_USER; 836 } 837 838 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 839 vfsp = NULL; 840 if ((fsflags & MNT_UPDATE) == 0) { 841 /* Don't try to load KLDs if we're mounting the root. */ 842 if (fsflags & MNT_ROOTFS) 843 vfsp = vfs_byname(fstype); 844 else 845 vfsp = vfs_byname_kld(fstype, td, &error); 846 if (vfsp == NULL) 847 return (ENODEV); 848 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL)) 849 return (EPERM); 850 } 851 /* 852 * Get vnode to be covered 853 */ 854 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE, 855 fspath, td); 856 if ((error = namei(&nd)) != 0) 857 return (error); 858 NDFREE(&nd, NDF_ONLY_PNBUF); 859 vp = nd.ni_vp; 860 if (fsflags & MNT_UPDATE) { 861 if ((vp->v_vflag & VV_ROOT) == 0) { 862 vput(vp); 863 return (EINVAL); 864 } 865 mp = vp->v_mount; 866 MNT_ILOCK(mp); 867 flag = mp->mnt_flag; 868 /* 869 * We only allow the filesystem to be reloaded if it 870 * is currently mounted read-only. 871 */ 872 if ((fsflags & MNT_RELOAD) && 873 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 874 MNT_IUNLOCK(mp); 875 vput(vp); 876 return (EOPNOTSUPP); /* Needs translation */ 877 } 878 MNT_IUNLOCK(mp); 879 /* 880 * Only privileged root, or (if MNT_USER is set) the user that 881 * did the original mount is permitted to update it. 882 */ 883 error = vfs_suser(mp, td); 884 if (error) { 885 vput(vp); 886 return (error); 887 } 888 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 889 vput(vp); 890 return (EBUSY); 891 } 892 VI_LOCK(vp); 893 if ((vp->v_iflag & VI_MOUNT) != 0 || 894 vp->v_mountedhere != NULL) { 895 VI_UNLOCK(vp); 896 vfs_unbusy(mp, td); 897 vput(vp); 898 return (EBUSY); 899 } 900 vp->v_iflag |= VI_MOUNT; 901 VI_UNLOCK(vp); 902 MNT_ILOCK(mp); 903 mp->mnt_flag |= fsflags & 904 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 905 MNT_IUNLOCK(mp); 906 VOP_UNLOCK(vp, 0, td); 907 mp->mnt_optnew = fsdata; 908 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 909 } else { 910 /* 911 * If the user is not root, ensure that they own the directory 912 * onto which we are attempting to mount. 913 */ 914 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 915 if (error) { 916 vput(vp); 917 return (error); 918 } 919 if (va.va_uid != td->td_ucred->cr_uid) { 920 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 921 SUSER_ALLOWJAIL); 922 if (error) { 923 vput(vp); 924 return (error); 925 } 926 } 927 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 928 if (error != 0) { 929 vput(vp); 930 return (error); 931 } 932 if (vp->v_type != VDIR) { 933 vput(vp); 934 return (ENOTDIR); 935 } 936 VI_LOCK(vp); 937 if ((vp->v_iflag & VI_MOUNT) != 0 || 938 vp->v_mountedhere != NULL) { 939 VI_UNLOCK(vp); 940 vput(vp); 941 return (EBUSY); 942 } 943 vp->v_iflag |= VI_MOUNT; 944 VI_UNLOCK(vp); 945 946 /* 947 * Allocate and initialize the filesystem. 948 */ 949 mp = vfs_mount_alloc(vp, vfsp, fspath, td); 950 VOP_UNLOCK(vp, 0, td); 951 952 /* XXXMAC: pass to vfs_mount_alloc? */ 953 mp->mnt_optnew = fsdata; 954 } 955 956 /* 957 * Set the mount level flags. 958 */ 959 MNT_ILOCK(mp); 960 mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) | 961 (fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS | 962 MNT_RDONLY)); 963 if ((mp->mnt_flag & MNT_ASYNC) == 0) 964 mp->mnt_kern_flag &= ~MNTK_ASYNC; 965 MNT_IUNLOCK(mp); 966 /* 967 * Mount the filesystem. 968 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 969 * get. No freeing of cn_pnbuf. 970 */ 971 error = VFS_MOUNT(mp, td); 972 973 /* 974 * Process the export option only if we are 975 * updating mount options. 976 */ 977 if (!error && (fsflags & MNT_UPDATE)) { 978 if (vfs_copyopt(mp->mnt_optnew, "export", &export, 979 sizeof(export)) == 0) 980 error = vfs_export(mp, &export); 981 } 982 983 if (!error) { 984 if (mp->mnt_opt != NULL) 985 vfs_freeopts(mp->mnt_opt); 986 mp->mnt_opt = mp->mnt_optnew; 987 (void)VFS_STATFS(mp, &mp->mnt_stat, td); 988 } 989 /* 990 * Prevent external consumers of mount options from reading 991 * mnt_optnew. 992 */ 993 mp->mnt_optnew = NULL; 994 if (mp->mnt_flag & MNT_UPDATE) { 995 MNT_ILOCK(mp); 996 if (error) 997 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | 998 (flag & ~MNT_QUOTA); 999 else 1000 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | 1001 MNT_FORCE | MNT_SNAPSHOT); 1002 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1003 mp->mnt_kern_flag |= MNTK_ASYNC; 1004 else 1005 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1006 MNT_IUNLOCK(mp); 1007 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1008 if (mp->mnt_syncer == NULL) 1009 error = vfs_allocate_syncvnode(mp); 1010 } else { 1011 if (mp->mnt_syncer != NULL) 1012 vrele(mp->mnt_syncer); 1013 mp->mnt_syncer = NULL; 1014 } 1015 vfs_unbusy(mp, td); 1016 VI_LOCK(vp); 1017 vp->v_iflag &= ~VI_MOUNT; 1018 VI_UNLOCK(vp); 1019 vrele(vp); 1020 return (error); 1021 } 1022 MNT_ILOCK(mp); 1023 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1024 mp->mnt_kern_flag |= MNTK_ASYNC; 1025 else 1026 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1027 MNT_IUNLOCK(mp); 1028 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1029 /* 1030 * Put the new filesystem on the mount list after root. 1031 */ 1032 cache_purge(vp); 1033 if (!error) { 1034 struct vnode *newdp; 1035 1036 VI_LOCK(vp); 1037 vp->v_iflag &= ~VI_MOUNT; 1038 VI_UNLOCK(vp); 1039 vp->v_mountedhere = mp; 1040 mtx_lock(&mountlist_mtx); 1041 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1042 mtx_unlock(&mountlist_mtx); 1043 vfs_event_signal(NULL, VQ_MOUNT, 0); 1044 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 1045 panic("mount: lost mount"); 1046 mountcheckdirs(vp, newdp); 1047 vput(newdp); 1048 VOP_UNLOCK(vp, 0, td); 1049 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1050 error = vfs_allocate_syncvnode(mp); 1051 vfs_unbusy(mp, td); 1052 if (error) 1053 vrele(vp); 1054 } else { 1055 VI_LOCK(vp); 1056 vp->v_iflag &= ~VI_MOUNT; 1057 VI_UNLOCK(vp); 1058 vfs_unbusy(mp, td); 1059 vfs_mount_destroy(mp); 1060 vput(vp); 1061 } 1062 return (error); 1063} 1064 1065/* 1066 * Unmount a filesystem. 1067 * 1068 * Note: unmount takes a path to the vnode mounted on as argument, not 1069 * special file (as before). 1070 */ 1071#ifndef _SYS_SYSPROTO_H_ 1072struct unmount_args { 1073 char *path; 1074 int flags; 1075}; 1076#endif 1077/* ARGSUSED */ 1078int 1079unmount(td, uap) 1080 struct thread *td; 1081 register struct unmount_args /* { 1082 char *path; 1083 int flags; 1084 } */ *uap; 1085{ 1086 struct mount *mp; 1087 char *pathbuf; 1088 int error, id0, id1; 1089 1090 if (jailed(td->td_ucred) || usermount == 0) { 1091 error = priv_check(td, PRIV_VFS_UNMOUNT); 1092 if (error) 1093 return (error); 1094 } 1095 1096 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1097 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1098 if (error) { 1099 free(pathbuf, M_TEMP); 1100 return (error); 1101 } 1102 AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1); 1103 mtx_lock(&Giant); 1104 if (uap->flags & MNT_BYFSID) { 1105 /* Decode the filesystem ID. */ 1106 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1107 mtx_unlock(&Giant); 1108 free(pathbuf, M_TEMP); 1109 return (EINVAL); 1110 } 1111 1112 mtx_lock(&mountlist_mtx); 1113 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1114 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1115 mp->mnt_stat.f_fsid.val[1] == id1) 1116 break; 1117 } 1118 mtx_unlock(&mountlist_mtx); 1119 } else { 1120 mtx_lock(&mountlist_mtx); 1121 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1122 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1123 break; 1124 } 1125 mtx_unlock(&mountlist_mtx); 1126 } 1127 free(pathbuf, M_TEMP); 1128 if (mp == NULL) { 1129 /* 1130 * Previously we returned ENOENT for a nonexistent path and 1131 * EINVAL for a non-mountpoint. We cannot tell these apart 1132 * now, so in the !MNT_BYFSID case return the more likely 1133 * EINVAL for compatibility. 1134 */ 1135 mtx_unlock(&Giant); 1136 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1137 } 1138 1139 /* 1140 * Don't allow unmounting the root filesystem. 1141 */ 1142 if (mp->mnt_flag & MNT_ROOTFS) { 1143 mtx_unlock(&Giant); 1144 return (EINVAL); 1145 } 1146 error = dounmount(mp, uap->flags, td); 1147 mtx_unlock(&Giant); 1148 return (error); 1149} 1150 1151/* 1152 * Do the actual filesystem unmount. 1153 */ 1154int 1155dounmount(mp, flags, td) 1156 struct mount *mp; 1157 int flags; 1158 struct thread *td; 1159{ 1160 struct vnode *coveredvp, *fsrootvp; 1161 int error; 1162 int async_flag; 1163 int mnt_gen_r; 1164 1165 mtx_assert(&Giant, MA_OWNED); 1166 1167 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 1168 mnt_gen_r = mp->mnt_gen; 1169 VI_LOCK(coveredvp); 1170 vholdl(coveredvp); 1171 error = vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK, td); 1172 vdrop(coveredvp); 1173 /* 1174 * Check for mp being unmounted while waiting for the 1175 * covered vnode lock. 1176 */ 1177 if (error) 1178 return (error); 1179 if (coveredvp->v_mountedhere != mp || 1180 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 1181 VOP_UNLOCK(coveredvp, 0, td); 1182 return (EBUSY); 1183 } 1184 } 1185 /* 1186 * Only privileged root, or (if MNT_USER is set) the user that did the 1187 * original mount is permitted to unmount this filesystem. 1188 */ 1189 error = vfs_suser(mp, td); 1190 if (error) { 1191 if (coveredvp) 1192 VOP_UNLOCK(coveredvp, 0, td); 1193 return (error); 1194 } 1195 1196 MNT_ILOCK(mp); 1197 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1198 MNT_IUNLOCK(mp); 1199 if (coveredvp) 1200 VOP_UNLOCK(coveredvp, 0, td); 1201 return (EBUSY); 1202 } 1203 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1204 /* Allow filesystems to detect that a forced unmount is in progress. */ 1205 if (flags & MNT_FORCE) 1206 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1207 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1208 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td); 1209 if (error) { 1210 MNT_ILOCK(mp); 1211 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1212 if (mp->mnt_kern_flag & MNTK_MWAIT) 1213 wakeup(mp); 1214 MNT_IUNLOCK(mp); 1215 if (coveredvp) 1216 VOP_UNLOCK(coveredvp, 0, td); 1217 return (error); 1218 } 1219 vn_start_write(NULL, &mp, V_WAIT); 1220 1221 if (mp->mnt_flag & MNT_EXPUBLIC) 1222 vfs_setpublicfs(NULL, NULL, NULL); 1223 1224 vfs_msync(mp, MNT_WAIT); 1225 MNT_ILOCK(mp); 1226 async_flag = mp->mnt_flag & MNT_ASYNC; 1227 mp->mnt_flag &= ~MNT_ASYNC; 1228 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1229 MNT_IUNLOCK(mp); 1230 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1231 if (mp->mnt_syncer != NULL) 1232 vrele(mp->mnt_syncer); 1233 /* 1234 * For forced unmounts, move process cdir/rdir refs on the fs root 1235 * vnode to the covered vnode. For non-forced unmounts we want 1236 * such references to cause an EBUSY error. 1237 */ 1238 if ((flags & MNT_FORCE) && 1239 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1240 if (mp->mnt_vnodecovered != NULL) 1241 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 1242 if (fsrootvp == rootvnode) { 1243 vrele(rootvnode); 1244 rootvnode = NULL; 1245 } 1246 vput(fsrootvp); 1247 } 1248 if (((mp->mnt_flag & MNT_RDONLY) || 1249 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 1250 (flags & MNT_FORCE)) { 1251 error = VFS_UNMOUNT(mp, flags, td); 1252 } 1253 vn_finished_write(mp); 1254 if (error) { 1255 /* Undo cdir/rdir and rootvnode changes made above. */ 1256 if ((flags & MNT_FORCE) && 1257 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1258 if (mp->mnt_vnodecovered != NULL) 1259 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 1260 if (rootvnode == NULL) { 1261 rootvnode = fsrootvp; 1262 vref(rootvnode); 1263 } 1264 vput(fsrootvp); 1265 } 1266 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1267 (void) vfs_allocate_syncvnode(mp); 1268 MNT_ILOCK(mp); 1269 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1270 mp->mnt_flag |= async_flag; 1271 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1272 mp->mnt_kern_flag |= MNTK_ASYNC; 1273 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1274 if (mp->mnt_kern_flag & MNTK_MWAIT) 1275 wakeup(mp); 1276 MNT_IUNLOCK(mp); 1277 if (coveredvp) 1278 VOP_UNLOCK(coveredvp, 0, td); 1279 return (error); 1280 } 1281 mtx_lock(&mountlist_mtx); 1282 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1283 mtx_unlock(&mountlist_mtx); 1284 if (coveredvp != NULL) { 1285 coveredvp->v_mountedhere = NULL; 1286 vput(coveredvp); 1287 } 1288 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1289 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1290 vfs_mount_destroy(mp); 1291 return (0); 1292} 1293 1294/* 1295 * --------------------------------------------------------------------- 1296 * Mounting of root filesystem 1297 * 1298 */ 1299 1300struct root_hold_token { 1301 const char *who; 1302 LIST_ENTRY(root_hold_token) list; 1303}; 1304 1305static LIST_HEAD(, root_hold_token) root_holds = 1306 LIST_HEAD_INITIALIZER(&root_holds); 1307 1308static int root_mount_complete; 1309 1310/* 1311 * Hold root mount. 1312 */ 1313struct root_hold_token * 1314root_mount_hold(const char *identifier) 1315{ 1316 struct root_hold_token *h; 1317 1318 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1319 h->who = identifier; 1320 mtx_lock(&mountlist_mtx); 1321 LIST_INSERT_HEAD(&root_holds, h, list); 1322 mtx_unlock(&mountlist_mtx); 1323 return (h); 1324} 1325 1326/* 1327 * Release root mount. 1328 */ 1329void 1330root_mount_rel(struct root_hold_token *h) 1331{ 1332 1333 mtx_lock(&mountlist_mtx); 1334 LIST_REMOVE(h, list); 1335 wakeup(&root_holds); 1336 mtx_unlock(&mountlist_mtx); 1337 free(h, M_DEVBUF); 1338} 1339 1340/* 1341 * Wait for all subsystems to release root mount. 1342 */ 1343static void 1344root_mount_prepare(void) 1345{ 1346 struct root_hold_token *h; 1347 1348 for (;;) { 1349 DROP_GIANT(); 1350 g_waitidle(); 1351 PICKUP_GIANT(); 1352 mtx_lock(&mountlist_mtx); 1353 if (LIST_EMPTY(&root_holds)) { 1354 mtx_unlock(&mountlist_mtx); 1355 break; 1356 } 1357 printf("Root mount waiting for:"); 1358 LIST_FOREACH(h, &root_holds, list) 1359 printf(" %s", h->who); 1360 printf("\n"); 1361 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1362 hz); 1363 } 1364} 1365 1366/* 1367 * Root was mounted, share the good news. 1368 */ 1369static void 1370root_mount_done(void) 1371{ 1372 1373 /* 1374 * Use a mutex to prevent the wakeup being missed and waiting for 1375 * an extra 1 second sleep. 1376 */ 1377 mtx_lock(&mountlist_mtx); 1378 root_mount_complete = 1; 1379 wakeup(&root_mount_complete); 1380 mtx_unlock(&mountlist_mtx); 1381} 1382 1383/* 1384 * Return true if root is already mounted. 1385 */ 1386int 1387root_mounted(void) 1388{ 1389 1390 /* No mutex is acquired here because int stores are atomic. */ 1391 return (root_mount_complete); 1392} 1393 1394/* 1395 * Wait until root is mounted. 1396 */ 1397void 1398root_mount_wait(void) 1399{ 1400 1401 /* 1402 * Panic on an obvious deadlock - the function can't be called from 1403 * a thread which is doing the whole SYSINIT stuff. 1404 */ 1405 KASSERT(curthread->td_proc->p_pid != 0, 1406 ("root_mount_wait: cannot be called from the swapper thread")); 1407 mtx_lock(&mountlist_mtx); 1408 while (!root_mount_complete) { 1409 msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait", 1410 hz); 1411 } 1412 mtx_unlock(&mountlist_mtx); 1413} 1414 1415static void 1416set_rootvnode(struct thread *td) 1417{ 1418 struct proc *p; 1419 1420 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1421 panic("Cannot find root vnode"); 1422 1423 p = td->td_proc; 1424 FILEDESC_SLOCK(p->p_fd); 1425 1426 if (p->p_fd->fd_cdir != NULL) 1427 vrele(p->p_fd->fd_cdir); 1428 p->p_fd->fd_cdir = rootvnode; 1429 VREF(rootvnode); 1430 1431 if (p->p_fd->fd_rdir != NULL) 1432 vrele(p->p_fd->fd_rdir); 1433 p->p_fd->fd_rdir = rootvnode; 1434 VREF(rootvnode); 1435 1436 FILEDESC_SUNLOCK(p->p_fd); 1437 1438 VOP_UNLOCK(rootvnode, 0, td); 1439} 1440 1441/* 1442 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1443 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1444 */ 1445 1446static void 1447devfs_first(void) 1448{ 1449 struct thread *td = curthread; 1450 struct vfsoptlist *opts; 1451 struct vfsconf *vfsp; 1452 struct mount *mp = NULL; 1453 int error; 1454 1455 vfsp = vfs_byname("devfs"); 1456 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1457 if (vfsp == NULL) 1458 return; 1459 1460 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td); 1461 1462 error = VFS_MOUNT(mp, td); 1463 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1464 if (error) 1465 return; 1466 1467 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 1468 TAILQ_INIT(opts); 1469 mp->mnt_opt = opts; 1470 1471 mtx_lock(&mountlist_mtx); 1472 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1473 mtx_unlock(&mountlist_mtx); 1474 1475 set_rootvnode(td); 1476 1477 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1478 if (error) 1479 printf("kern_symlink /dev -> / returns %d\n", error); 1480} 1481 1482/* 1483 * Surgically move our devfs to be mounted on /dev. 1484 */ 1485 1486static void 1487devfs_fixup(struct thread *td) 1488{ 1489 struct nameidata nd; 1490 int error; 1491 struct vnode *vp, *dvp; 1492 struct mount *mp; 1493 1494 /* Remove our devfs mount from the mountlist and purge the cache */ 1495 mtx_lock(&mountlist_mtx); 1496 mp = TAILQ_FIRST(&mountlist); 1497 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1498 mtx_unlock(&mountlist_mtx); 1499 cache_purgevfs(mp); 1500 1501 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1502 VI_LOCK(dvp); 1503 dvp->v_iflag &= ~VI_MOUNT; 1504 dvp->v_mountedhere = NULL; 1505 VI_UNLOCK(dvp); 1506 1507 /* Set up the real rootvnode, and purge the cache */ 1508 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1509 set_rootvnode(td); 1510 cache_purgevfs(rootvnode->v_mount); 1511 1512 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1513 error = namei(&nd); 1514 if (error) { 1515 printf("Lookup of /dev for devfs, error: %d\n", error); 1516 return; 1517 } 1518 NDFREE(&nd, NDF_ONLY_PNBUF); 1519 vp = nd.ni_vp; 1520 if (vp->v_type != VDIR) { 1521 vput(vp); 1522 } 1523 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1524 if (error) { 1525 vput(vp); 1526 } 1527 cache_purge(vp); 1528 mp->mnt_vnodecovered = vp; 1529 vp->v_mountedhere = mp; 1530 mtx_lock(&mountlist_mtx); 1531 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1532 mtx_unlock(&mountlist_mtx); 1533 VOP_UNLOCK(vp, 0, td); 1534 vput(dvp); 1535 vfs_unbusy(mp, td); 1536 1537 /* Unlink the no longer needed /dev/dev -> / symlink */ 1538 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1539} 1540 1541/* 1542 * Report errors during filesystem mounting. 1543 */ 1544void 1545vfs_mount_error(struct mount *mp, const char *fmt, ...) 1546{ 1547 struct vfsoptlist *moptlist = mp->mnt_optnew; 1548 va_list ap; 1549 int error, len; 1550 char *errmsg; 1551 1552 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1553 if (error || errmsg == NULL || len <= 0) 1554 return; 1555 1556 va_start(ap, fmt); 1557 vsnprintf(errmsg, (size_t)len, fmt, ap); 1558 va_end(ap); 1559} 1560 1561/* 1562 * Find and mount the root filesystem 1563 */ 1564void 1565vfs_mountroot(void) 1566{ 1567 char *cp; 1568 int error, i, asked = 0; 1569 1570 root_mount_prepare(); 1571 1572 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), 1573 NULL, NULL, mount_init, mount_fini, 1574 UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1575 devfs_first(); 1576 1577 /* 1578 * We are booted with instructions to prompt for the root filesystem. 1579 */ 1580 if (boothowto & RB_ASKNAME) { 1581 if (!vfs_mountroot_ask()) 1582 goto mounted; 1583 asked = 1; 1584 } 1585 1586 /* 1587 * The root filesystem information is compiled in, and we are 1588 * booted with instructions to use it. 1589 */ 1590 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1591 if (!vfs_mountroot_try(ctrootdevname)) 1592 goto mounted; 1593 ctrootdevname = NULL; 1594 } 1595 1596 /* 1597 * We've been given the generic "use CDROM as root" flag. This is 1598 * necessary because one media may be used in many different 1599 * devices, so we need to search for them. 1600 */ 1601 if (boothowto & RB_CDROM) { 1602 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1603 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1604 goto mounted; 1605 } 1606 } 1607 1608 /* 1609 * Try to use the value read by the loader from /etc/fstab, or 1610 * supplied via some other means. This is the preferred 1611 * mechanism. 1612 */ 1613 cp = getenv("vfs.root.mountfrom"); 1614 if (cp != NULL) { 1615 error = vfs_mountroot_try(cp); 1616 freeenv(cp); 1617 if (!error) 1618 goto mounted; 1619 } 1620 1621 /* 1622 * Try values that may have been computed by code during boot 1623 */ 1624 if (!vfs_mountroot_try(rootdevnames[0])) 1625 goto mounted; 1626 if (!vfs_mountroot_try(rootdevnames[1])) 1627 goto mounted; 1628 1629 /* 1630 * If we (still) have a compiled-in default, try it. 1631 */ 1632 if (ctrootdevname != NULL) 1633 if (!vfs_mountroot_try(ctrootdevname)) 1634 goto mounted; 1635 /* 1636 * Everything so far has failed, prompt on the console if we haven't 1637 * already tried that. 1638 */ 1639 if (!asked) 1640 if (!vfs_mountroot_ask()) 1641 goto mounted; 1642 1643 panic("Root mount failed, startup aborted."); 1644 1645mounted: 1646 root_mount_done(); 1647} 1648 1649/* 1650 * Mount (mountfrom) as the root filesystem. 1651 */ 1652static int 1653vfs_mountroot_try(const char *mountfrom) 1654{ 1655 struct mount *mp; 1656 char *vfsname, *path; 1657 time_t timebase; 1658 int error; 1659 char patt[32]; 1660 1661 vfsname = NULL; 1662 path = NULL; 1663 mp = NULL; 1664 error = EINVAL; 1665 1666 if (mountfrom == NULL) 1667 return (error); /* don't complain */ 1668 printf("Trying to mount root from %s\n", mountfrom); 1669 1670 /* parse vfs name and path */ 1671 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1672 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1673 vfsname[0] = path[0] = 0; 1674 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1675 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1676 goto out; 1677 1678 if (path[0] == '\0') 1679 strcpy(path, ROOTNAME); 1680 1681 error = kernel_vmount( 1682 MNT_RDONLY | MNT_ROOTFS, 1683 "fstype", vfsname, 1684 "fspath", "/", 1685 "from", path, 1686 NULL); 1687 if (error == 0) { 1688 /* 1689 * We mount devfs prior to mounting the / FS, so the first 1690 * entry will typically be devfs. 1691 */ 1692 mp = TAILQ_FIRST(&mountlist); 1693 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1694 1695 /* 1696 * Iterate over all currently mounted file systems and use 1697 * the time stamp found to check and/or initialize the RTC. 1698 * Typically devfs has no time stamp and the only other FS 1699 * is the actual / FS. 1700 * Call inittodr() only once and pass it the largest of the 1701 * timestamps we encounter. 1702 */ 1703 timebase = 0; 1704 do { 1705 if (mp->mnt_time > timebase) 1706 timebase = mp->mnt_time; 1707 mp = TAILQ_NEXT(mp, mnt_list); 1708 } while (mp != NULL); 1709 inittodr(timebase); 1710 1711 devfs_fixup(curthread); 1712 } 1713out: 1714 free(path, M_MOUNT); 1715 free(vfsname, M_MOUNT); 1716 return (error); 1717} 1718 1719/* 1720 * --------------------------------------------------------------------- 1721 * Interactive root filesystem selection code. 1722 */ 1723 1724static int 1725vfs_mountroot_ask(void) 1726{ 1727 char name[128]; 1728 1729 for(;;) { 1730 printf("\nManual root filesystem specification:\n"); 1731 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1732#if defined(__amd64__) || defined(__i386__) || defined(__ia64__) 1733 printf(" eg. ufs:da0s1a\n"); 1734#else 1735 printf(" eg. ufs:/dev/da0a\n"); 1736#endif 1737 printf(" ? List valid disk boot devices\n"); 1738 printf(" <empty line> Abort manual input\n"); 1739 printf("\nmountroot> "); 1740 gets(name, sizeof(name), 1); 1741 if (name[0] == '\0') 1742 return (1); 1743 if (name[0] == '?') { 1744 printf("\nList of GEOM managed disk devices:\n "); 1745 g_dev_print(); 1746 continue; 1747 } 1748 if (!vfs_mountroot_try(name)) 1749 return (0); 1750 } 1751} 1752 1753/* 1754 * --------------------------------------------------------------------- 1755 * Functions for querying mount options/arguments from filesystems. 1756 */ 1757 1758/* 1759 * Check that no unknown options are given 1760 */ 1761int 1762vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1763{ 1764 struct vfsopt *opt; 1765 const char **t, *p; 1766 1767 TAILQ_FOREACH(opt, opts, link) { 1768 p = opt->name; 1769 if (p[0] == 'n' && p[1] == 'o') 1770 p += 2; 1771 for(t = global_opts; *t != NULL; t++) 1772 if (!strcmp(*t, p)) 1773 break; 1774 if (*t != NULL) 1775 continue; 1776 for(t = legal; *t != NULL; t++) 1777 if (!strcmp(*t, p)) 1778 break; 1779 if (*t != NULL) 1780 continue; 1781 printf("mount option <%s> is unknown\n", p); 1782 return (EINVAL); 1783 } 1784 return (0); 1785} 1786 1787/* 1788 * Get a mount option by its name. 1789 * 1790 * Return 0 if the option was found, ENOENT otherwise. 1791 * If len is non-NULL it will be filled with the length 1792 * of the option. If buf is non-NULL, it will be filled 1793 * with the address of the option. 1794 */ 1795int 1796vfs_getopt(opts, name, buf, len) 1797 struct vfsoptlist *opts; 1798 const char *name; 1799 void **buf; 1800 int *len; 1801{ 1802 struct vfsopt *opt; 1803 1804 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1805 1806 TAILQ_FOREACH(opt, opts, link) { 1807 if (strcmp(name, opt->name) == 0) { 1808 if (len != NULL) 1809 *len = opt->len; 1810 if (buf != NULL) 1811 *buf = opt->value; 1812 return (0); 1813 } 1814 } 1815 return (ENOENT); 1816} 1817 1818static int 1819vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1820{ 1821 struct vfsopt *opt; 1822 int i; 1823 1824 if (opts == NULL) 1825 return (-1); 1826 1827 i = 0; 1828 TAILQ_FOREACH(opt, opts, link) { 1829 if (strcmp(name, opt->name) == 0) 1830 return (i); 1831 ++i; 1832 } 1833 return (-1); 1834} 1835 1836char * 1837vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1838{ 1839 struct vfsopt *opt; 1840 1841 *error = 0; 1842 TAILQ_FOREACH(opt, opts, link) { 1843 if (strcmp(name, opt->name) != 0) 1844 continue; 1845 if (((char *)opt->value)[opt->len - 1] != '\0') { 1846 *error = EINVAL; 1847 return (NULL); 1848 } 1849 return (opt->value); 1850 } 1851 *error = ENOENT; 1852 return (NULL); 1853} 1854 1855int 1856vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1857{ 1858 struct vfsopt *opt; 1859 1860 TAILQ_FOREACH(opt, opts, link) { 1861 if (strcmp(name, opt->name) == 0) { 1862 if (w != NULL) 1863 *w |= val; 1864 return (1); 1865 } 1866 } 1867 if (w != NULL) 1868 *w &= ~val; 1869 return (0); 1870} 1871 1872int 1873vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1874{ 1875 va_list ap; 1876 struct vfsopt *opt; 1877 int ret; 1878 1879 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1880 1881 TAILQ_FOREACH(opt, opts, link) { 1882 if (strcmp(name, opt->name) != 0) 1883 continue; 1884 if (((char *)opt->value)[opt->len - 1] != '\0') 1885 return (0); 1886 va_start(ap, fmt); 1887 ret = vsscanf(opt->value, fmt, ap); 1888 va_end(ap); 1889 return (ret); 1890 } 1891 return (0); 1892} 1893 1894/* 1895 * Find and copy a mount option. 1896 * 1897 * The size of the buffer has to be specified 1898 * in len, if it is not the same length as the 1899 * mount option, EINVAL is returned. 1900 * Returns ENOENT if the option is not found. 1901 */ 1902int 1903vfs_copyopt(opts, name, dest, len) 1904 struct vfsoptlist *opts; 1905 const char *name; 1906 void *dest; 1907 int len; 1908{ 1909 struct vfsopt *opt; 1910 1911 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1912 1913 TAILQ_FOREACH(opt, opts, link) { 1914 if (strcmp(name, opt->name) == 0) { 1915 if (len != opt->len) 1916 return (EINVAL); 1917 bcopy(opt->value, dest, opt->len); 1918 return (0); 1919 } 1920 } 1921 return (ENOENT); 1922} 1923 1924/* 1925 * This is a helper function for filesystems to traverse their 1926 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1927 */ 1928 1929struct vnode * 1930__mnt_vnode_next(struct vnode **mvp, struct mount *mp) 1931{ 1932 struct vnode *vp; 1933 1934 mtx_assert(MNT_MTX(mp), MA_OWNED); 1935 1936 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 1937 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 1938 while (vp != NULL && vp->v_type == VMARKER) 1939 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1940 1941 /* Check if we are done */ 1942 if (vp == NULL) { 1943 __mnt_vnode_markerfree(mvp, mp); 1944 return (NULL); 1945 } 1946 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 1947 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1948 return (vp); 1949} 1950 1951struct vnode * 1952__mnt_vnode_first(struct vnode **mvp, struct mount *mp) 1953{ 1954 struct vnode *vp; 1955 1956 mtx_assert(MNT_MTX(mp), MA_OWNED); 1957 1958 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1959 while (vp != NULL && vp->v_type == VMARKER) 1960 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1961 1962 /* Check if we are done */ 1963 if (vp == NULL) { 1964 *mvp = NULL; 1965 return (NULL); 1966 } 1967 mp->mnt_holdcnt++; 1968 MNT_IUNLOCK(mp); 1969 *mvp = (struct vnode *) malloc(sizeof(struct vnode), 1970 M_VNODE_MARKER, 1971 M_WAITOK | M_ZERO); 1972 MNT_ILOCK(mp); 1973 (*mvp)->v_type = VMARKER; 1974 1975 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1976 while (vp != NULL && vp->v_type == VMARKER) 1977 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1978 1979 /* Check if we are done */ 1980 if (vp == NULL) { 1981 MNT_IUNLOCK(mp); 1982 free(*mvp, M_VNODE_MARKER); 1983 MNT_ILOCK(mp); 1984 *mvp = NULL; 1985 mp->mnt_holdcnt--; 1986 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 1987 wakeup(&mp->mnt_holdcnt); 1988 return (NULL); 1989 } 1990 mp->mnt_markercnt++; 1991 (*mvp)->v_mount = mp; 1992 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1993 return (vp); 1994} 1995 1996 1997void 1998__mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp) 1999{ 2000 2001 if (*mvp == NULL) 2002 return; 2003 2004 mtx_assert(MNT_MTX(mp), MA_OWNED); 2005 2006 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 2007 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 2008 MNT_IUNLOCK(mp); 2009 free(*mvp, M_VNODE_MARKER); 2010 MNT_ILOCK(mp); 2011 *mvp = NULL; 2012 2013 mp->mnt_markercnt--; 2014 mp->mnt_holdcnt--; 2015 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 2016 wakeup(&mp->mnt_holdcnt); 2017} 2018 2019 2020int 2021__vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 2022{ 2023 int error; 2024 2025 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 2026 if (sbp != &mp->mnt_stat) 2027 *sbp = mp->mnt_stat; 2028 return (error); 2029} 2030 2031void 2032vfs_mountedfrom(struct mount *mp, const char *from) 2033{ 2034 2035 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2036 strlcpy(mp->mnt_stat.f_mntfromname, from, 2037 sizeof mp->mnt_stat.f_mntfromname); 2038} 2039 2040/* 2041 * --------------------------------------------------------------------- 2042 * This is the api for building mount args and mounting filesystems from 2043 * inside the kernel. 2044 * 2045 * The API works by accumulation of individual args. First error is 2046 * latched. 2047 * 2048 * XXX: should be documented in new manpage kernel_mount(9) 2049 */ 2050 2051/* A memory allocation which must be freed when we are done */ 2052struct mntaarg { 2053 SLIST_ENTRY(mntaarg) next; 2054}; 2055 2056/* The header for the mount arguments */ 2057struct mntarg { 2058 struct iovec *v; 2059 int len; 2060 int error; 2061 SLIST_HEAD(, mntaarg) list; 2062}; 2063 2064/* 2065 * Add a boolean argument. 2066 * 2067 * flag is the boolean value. 2068 * name must start with "no". 2069 */ 2070struct mntarg * 2071mount_argb(struct mntarg *ma, int flag, const char *name) 2072{ 2073 2074 KASSERT(name[0] == 'n' && name[1] == 'o', 2075 ("mount_argb(...,%s): name must start with 'no'", name)); 2076 2077 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2078} 2079 2080/* 2081 * Add an argument printf style 2082 */ 2083struct mntarg * 2084mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2085{ 2086 va_list ap; 2087 struct mntaarg *maa; 2088 struct sbuf *sb; 2089 int len; 2090 2091 if (ma == NULL) { 2092 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2093 SLIST_INIT(&ma->list); 2094 } 2095 if (ma->error) 2096 return (ma); 2097 2098 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2099 M_MOUNT, M_WAITOK); 2100 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2101 ma->v[ma->len].iov_len = strlen(name) + 1; 2102 ma->len++; 2103 2104 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 2105 va_start(ap, fmt); 2106 sbuf_vprintf(sb, fmt, ap); 2107 va_end(ap); 2108 sbuf_finish(sb); 2109 len = sbuf_len(sb) + 1; 2110 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2111 SLIST_INSERT_HEAD(&ma->list, maa, next); 2112 bcopy(sbuf_data(sb), maa + 1, len); 2113 sbuf_delete(sb); 2114 2115 ma->v[ma->len].iov_base = maa + 1; 2116 ma->v[ma->len].iov_len = len; 2117 ma->len++; 2118 2119 return (ma); 2120} 2121 2122/* 2123 * Add an argument which is a userland string. 2124 */ 2125struct mntarg * 2126mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2127{ 2128 struct mntaarg *maa; 2129 char *tbuf; 2130 2131 if (val == NULL) 2132 return (ma); 2133 if (ma == NULL) { 2134 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2135 SLIST_INIT(&ma->list); 2136 } 2137 if (ma->error) 2138 return (ma); 2139 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2140 SLIST_INSERT_HEAD(&ma->list, maa, next); 2141 tbuf = (void *)(maa + 1); 2142 ma->error = copyinstr(val, tbuf, len, NULL); 2143 return (mount_arg(ma, name, tbuf, -1)); 2144} 2145 2146/* 2147 * Plain argument. 2148 * 2149 * If length is -1, use printf. 2150 */ 2151struct mntarg * 2152mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2153{ 2154 2155 if (ma == NULL) { 2156 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2157 SLIST_INIT(&ma->list); 2158 } 2159 if (ma->error) 2160 return (ma); 2161 2162 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2163 M_MOUNT, M_WAITOK); 2164 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2165 ma->v[ma->len].iov_len = strlen(name) + 1; 2166 ma->len++; 2167 2168 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2169 if (len < 0) 2170 ma->v[ma->len].iov_len = strlen(val) + 1; 2171 else 2172 ma->v[ma->len].iov_len = len; 2173 ma->len++; 2174 return (ma); 2175} 2176 2177/* 2178 * Free a mntarg structure 2179 */ 2180static void 2181free_mntarg(struct mntarg *ma) 2182{ 2183 struct mntaarg *maa; 2184 2185 while (!SLIST_EMPTY(&ma->list)) { 2186 maa = SLIST_FIRST(&ma->list); 2187 SLIST_REMOVE_HEAD(&ma->list, next); 2188 free(maa, M_MOUNT); 2189 } 2190 free(ma->v, M_MOUNT); 2191 free(ma, M_MOUNT); 2192} 2193 2194/* 2195 * Mount a filesystem 2196 */ 2197int 2198kernel_mount(struct mntarg *ma, int flags) 2199{ 2200 struct uio auio; 2201 int error; 2202 2203 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2204 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2205 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2206 2207 auio.uio_iov = ma->v; 2208 auio.uio_iovcnt = ma->len; 2209 auio.uio_segflg = UIO_SYSSPACE; 2210 2211 error = ma->error; 2212 if (!error) 2213 error = vfs_donmount(curthread, flags, &auio); 2214 free_mntarg(ma); 2215 return (error); 2216} 2217 2218/* 2219 * A printflike function to mount a filesystem. 2220 */ 2221int 2222kernel_vmount(int flags, ...) 2223{ 2224 struct mntarg *ma = NULL; 2225 va_list ap; 2226 const char *cp; 2227 const void *vp; 2228 int error; 2229 2230 va_start(ap, flags); 2231 for (;;) { 2232 cp = va_arg(ap, const char *); 2233 if (cp == NULL) 2234 break; 2235 vp = va_arg(ap, const void *); 2236 ma = mount_arg(ma, cp, vp, -1); 2237 } 2238 va_end(ap); 2239 2240 error = kernel_mount(ma, flags); 2241 return (error); 2242} 2243