vfs_mount.c revision 168506
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 168506 2007-04-08 23:54:01Z 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 struct mount *vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp, 84 const char *fspath, struct thread *td); 85static int vfs_mountroot_ask(void); 86static int vfs_mountroot_try(const char *mountfrom); 87static int vfs_donmount(struct thread *td, int fsflags, 88 struct uio *fsoptions); 89static void free_mntarg(struct mntarg *ma); 90static int vfs_getopt_pos(struct vfsoptlist *opts, const char *name); 91 92static int usermount = 0; 93SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 94 "Unprivileged users may mount and unmount file systems"); 95 96MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 97MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 98static uma_zone_t mount_zone; 99 100/* List of mounted filesystems. */ 101struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 102 103/* For any iteration/modification of mountlist */ 104struct mtx mountlist_mtx; 105MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 106 107TAILQ_HEAD(vfsoptlist, vfsopt); 108struct vfsopt { 109 TAILQ_ENTRY(vfsopt) link; 110 char *name; 111 void *value; 112 int len; 113}; 114 115/* 116 * The vnode of the system's root (/ in the filesystem, without chroot 117 * active.) 118 */ 119struct vnode *rootvnode; 120 121/* 122 * The root filesystem is detailed in the kernel environment variable 123 * vfs.root.mountfrom, which is expected to be in the general format 124 * 125 * <vfsname>:[<path>] 126 * vfsname := the name of a VFS known to the kernel and capable 127 * of being mounted as root 128 * path := disk device name or other data used by the filesystem 129 * to locate its physical store 130 */ 131 132/* 133 * Global opts, taken by all filesystems 134 */ 135static const char *global_opts[] = { 136 "errmsg", 137 "fstype", 138 "fspath", 139 "rdonly", 140 "ro", 141 "rw", 142 "suid", 143 "exec", 144 "update", 145 NULL 146}; 147 148/* 149 * The root specifiers we will try if RB_CDROM is specified. 150 */ 151static char *cdrom_rootdevnames[] = { 152 "cd9660:cd0", 153 "cd9660:acd0", 154 NULL 155}; 156 157/* legacy find-root code */ 158char *rootdevnames[2] = {NULL, NULL}; 159#ifndef ROOTDEVNAME 160# define ROOTDEVNAME NULL 161#endif 162static const char *ctrootdevname = ROOTDEVNAME; 163 164/* 165 * --------------------------------------------------------------------- 166 * Functions for building and sanitizing the mount options 167 */ 168 169/* Remove one mount option. */ 170static void 171vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 172{ 173 174 TAILQ_REMOVE(opts, opt, link); 175 free(opt->name, M_MOUNT); 176 if (opt->value != NULL) 177 free(opt->value, M_MOUNT); 178#ifdef INVARIANTS 179 else if (opt->len != 0) 180 panic("%s: mount option with NULL value but length != 0", 181 __func__); 182#endif 183 free(opt, M_MOUNT); 184} 185 186/* Release all resources related to the mount options. */ 187void 188vfs_freeopts(struct vfsoptlist *opts) 189{ 190 struct vfsopt *opt; 191 192 while (!TAILQ_EMPTY(opts)) { 193 opt = TAILQ_FIRST(opts); 194 vfs_freeopt(opts, opt); 195 } 196 free(opts, M_MOUNT); 197} 198 199void 200vfs_deleteopt(struct vfsoptlist *opts, const char *name) 201{ 202 struct vfsopt *opt, *temp; 203 204 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 205 if (strcmp(opt->name, name) == 0) 206 vfs_freeopt(opts, opt); 207 } 208} 209 210/* 211 * Check if options are equal (with or without the "no" prefix). 212 */ 213static int 214vfs_equalopts(const char *opt1, const char *opt2) 215{ 216 217 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 218 if (strcmp(opt1, opt2) == 0) 219 return (1); 220 /* "noopt" vs. "opt" */ 221 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 222 return (1); 223 /* "opt" vs. "noopt" */ 224 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 225 return (1); 226 return (0); 227} 228 229/* 230 * If a mount option is specified several times, 231 * (with or without the "no" prefix) only keep 232 * the last occurence of it. 233 */ 234static void 235vfs_sanitizeopts(struct vfsoptlist *opts) 236{ 237 struct vfsopt *opt, *opt2, *tmp; 238 239 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 240 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 241 while (opt2 != NULL) { 242 if (vfs_equalopts(opt->name, opt2->name)) { 243 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 244 vfs_freeopt(opts, opt2); 245 opt2 = tmp; 246 } else { 247 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 248 } 249 } 250 } 251} 252 253/* 254 * Build a linked list of mount options from a struct uio. 255 */ 256static int 257vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 258{ 259 struct vfsoptlist *opts; 260 struct vfsopt *opt; 261 size_t memused; 262 unsigned int i, iovcnt; 263 int error, namelen, optlen; 264 265 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 266 TAILQ_INIT(opts); 267 memused = 0; 268 iovcnt = auio->uio_iovcnt; 269 for (i = 0; i < iovcnt; i += 2) { 270 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 271 namelen = auio->uio_iov[i].iov_len; 272 optlen = auio->uio_iov[i + 1].iov_len; 273 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 274 opt->value = NULL; 275 opt->len = 0; 276 277 /* 278 * Do this early, so jumps to "bad" will free the current 279 * option. 280 */ 281 TAILQ_INSERT_TAIL(opts, opt, link); 282 memused += sizeof(struct vfsopt) + optlen + namelen; 283 284 /* 285 * Avoid consuming too much memory, and attempts to overflow 286 * memused. 287 */ 288 if (memused > VFS_MOUNTARG_SIZE_MAX || 289 optlen > VFS_MOUNTARG_SIZE_MAX || 290 namelen > VFS_MOUNTARG_SIZE_MAX) { 291 error = EINVAL; 292 goto bad; 293 } 294 295 if (auio->uio_segflg == UIO_SYSSPACE) { 296 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 297 } else { 298 error = copyin(auio->uio_iov[i].iov_base, opt->name, 299 namelen); 300 if (error) 301 goto bad; 302 } 303 /* Ensure names are null-terminated strings. */ 304 if (opt->name[namelen - 1] != '\0') { 305 error = EINVAL; 306 goto bad; 307 } 308 if (optlen != 0) { 309 opt->len = optlen; 310 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 311 if (auio->uio_segflg == UIO_SYSSPACE) { 312 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 313 optlen); 314 } else { 315 error = copyin(auio->uio_iov[i + 1].iov_base, 316 opt->value, optlen); 317 if (error) 318 goto bad; 319 } 320 } 321 } 322 vfs_sanitizeopts(opts); 323 *options = opts; 324 return (0); 325bad: 326 vfs_freeopts(opts); 327 return (error); 328} 329 330/* 331 * Merge the old mount options with the new ones passed 332 * in the MNT_UPDATE case. 333 */ 334static void 335vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 336{ 337 struct vfsopt *opt, *opt2, *new; 338 339 TAILQ_FOREACH(opt, opts, link) { 340 /* 341 * Check that this option hasn't been redefined 342 * nor cancelled with a "no" mount option. 343 */ 344 opt2 = TAILQ_FIRST(toopts); 345 while (opt2 != NULL) { 346 if (strcmp(opt2->name, opt->name) == 0) 347 goto next; 348 if (strncmp(opt2->name, "no", 2) == 0 && 349 strcmp(opt2->name + 2, opt->name) == 0) { 350 vfs_freeopt(toopts, opt2); 351 goto next; 352 } 353 opt2 = TAILQ_NEXT(opt2, link); 354 } 355 /* We want this option, duplicate it. */ 356 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 357 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 358 strcpy(new->name, opt->name); 359 if (opt->len != 0) { 360 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 361 bcopy(opt->value, new->value, opt->len); 362 } else { 363 new->value = NULL; 364 } 365 new->len = opt->len; 366 TAILQ_INSERT_TAIL(toopts, new, link); 367next: 368 continue; 369 } 370} 371 372/* 373 * Mount a filesystem. 374 */ 375int 376nmount(td, uap) 377 struct thread *td; 378 struct nmount_args /* { 379 struct iovec *iovp; 380 unsigned int iovcnt; 381 int flags; 382 } */ *uap; 383{ 384 struct uio *auio; 385 struct iovec *iov; 386 unsigned int i; 387 int error; 388 u_int iovcnt; 389 390 AUDIT_ARG(fflags, uap->flags); 391 392 /* Kick out MNT_ROOTFS early as it is legal internally */ 393 if (uap->flags & MNT_ROOTFS) 394 return (EINVAL); 395 396 iovcnt = uap->iovcnt; 397 /* 398 * Check that we have an even number of iovec's 399 * and that we have at least two options. 400 */ 401 if ((iovcnt & 1) || (iovcnt < 4)) 402 return (EINVAL); 403 404 error = copyinuio(uap->iovp, iovcnt, &auio); 405 if (error) 406 return (error); 407 iov = auio->uio_iov; 408 for (i = 0; i < iovcnt; i++) { 409 if (iov->iov_len > MMAXOPTIONLEN) { 410 free(auio, M_IOV); 411 return (EINVAL); 412 } 413 iov++; 414 } 415 error = vfs_donmount(td, uap->flags, auio); 416 417 free(auio, M_IOV); 418 return (error); 419} 420 421/* 422 * --------------------------------------------------------------------- 423 * Various utility functions 424 */ 425 426void 427vfs_ref(struct mount *mp) 428{ 429 430 MNT_ILOCK(mp); 431 MNT_REF(mp); 432 MNT_IUNLOCK(mp); 433} 434 435void 436vfs_rel(struct mount *mp) 437{ 438 439 MNT_ILOCK(mp); 440 MNT_REL(mp); 441 MNT_IUNLOCK(mp); 442} 443 444static int 445mount_init(void *mem, int size, int flags) 446{ 447 struct mount *mp; 448 449 mp = (struct mount *)mem; 450 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 451 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 452 return (0); 453} 454 455static void 456mount_fini(void *mem, int size) 457{ 458 struct mount *mp; 459 460 mp = (struct mount *)mem; 461 lockdestroy(&mp->mnt_lock); 462 mtx_destroy(&mp->mnt_mtx); 463} 464 465/* 466 * Allocate and initialize the mount point struct. 467 */ 468static struct mount * 469vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 470 const char *fspath, struct thread *td) 471{ 472 struct mount *mp; 473 474 mp = uma_zalloc(mount_zone, M_WAITOK); 475 bzero(&mp->mnt_startzero, 476 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 477 TAILQ_INIT(&mp->mnt_nvnodelist); 478 mp->mnt_nvnodelistsize = 0; 479 mp->mnt_ref = 0; 480 (void) vfs_busy(mp, LK_NOWAIT, 0, td); 481 mp->mnt_op = vfsp->vfc_vfsops; 482 mp->mnt_vfc = vfsp; 483 vfsp->vfc_refcount++; /* XXX Unlocked */ 484 mp->mnt_stat.f_type = vfsp->vfc_typenum; 485 mp->mnt_gen++; 486 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 487 mp->mnt_vnodecovered = vp; 488 mp->mnt_cred = crdup(td->td_ucred); 489 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 490 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 491 mp->mnt_iosize_max = DFLTPHYS; 492#ifdef MAC 493 mac_init_mount(mp); 494 mac_create_mount(td->td_ucred, mp); 495#endif 496 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 497 return (mp); 498} 499 500/* 501 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 502 */ 503void 504vfs_mount_destroy(struct mount *mp) 505{ 506 int i; 507 508 MNT_ILOCK(mp); 509 for (i = 0; mp->mnt_ref && i < 3; i++) 510 msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz); 511 /* 512 * This will always cause a 3 second delay in rebooting due to 513 * refs on the root mountpoint that never go away. Most of these 514 * are held by init which never exits. 515 */ 516 if (i == 3 && (!rebooting || bootverbose)) 517 printf("Mount point %s had %d dangling refs\n", 518 mp->mnt_stat.f_mntonname, mp->mnt_ref); 519 if (mp->mnt_holdcnt != 0) { 520 printf("Waiting for mount point to be unheld\n"); 521 while (mp->mnt_holdcnt != 0) { 522 mp->mnt_holdcntwaiters++; 523 msleep(&mp->mnt_holdcnt, MNT_MTX(mp), 524 PZERO, "mntdestroy", 0); 525 mp->mnt_holdcntwaiters--; 526 } 527 printf("mount point unheld\n"); 528 } 529 if (mp->mnt_writeopcount > 0) { 530 printf("Waiting for mount point write ops\n"); 531 while (mp->mnt_writeopcount > 0) { 532 mp->mnt_kern_flag |= MNTK_SUSPEND; 533 msleep(&mp->mnt_writeopcount, 534 MNT_MTX(mp), 535 PZERO, "mntdestroy2", 0); 536 } 537 printf("mount point write ops completed\n"); 538 } 539 if (mp->mnt_secondary_writes > 0) { 540 printf("Waiting for mount point secondary write ops\n"); 541 while (mp->mnt_secondary_writes > 0) { 542 mp->mnt_kern_flag |= MNTK_SUSPEND; 543 msleep(&mp->mnt_secondary_writes, 544 MNT_MTX(mp), 545 PZERO, "mntdestroy3", 0); 546 } 547 printf("mount point secondary write ops completed\n"); 548 } 549 MNT_IUNLOCK(mp); 550 mp->mnt_vfc->vfc_refcount--; 551 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 552 struct vnode *vp; 553 554 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 555 vprint("", vp); 556 panic("unmount: dangling vnode"); 557 } 558 MNT_ILOCK(mp); 559 if (mp->mnt_kern_flag & MNTK_MWAIT) 560 wakeup(mp); 561 if (mp->mnt_writeopcount != 0) 562 panic("vfs_mount_destroy: nonzero writeopcount"); 563 if (mp->mnt_secondary_writes != 0) 564 panic("vfs_mount_destroy: nonzero secondary_writes"); 565 if (mp->mnt_nvnodelistsize != 0) 566 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 567 mp->mnt_writeopcount = -1000; 568 mp->mnt_nvnodelistsize = -1000; 569 mp->mnt_secondary_writes = -1000; 570 MNT_IUNLOCK(mp); 571#ifdef MAC 572 mac_destroy_mount(mp); 573#endif 574 if (mp->mnt_opt != NULL) 575 vfs_freeopts(mp->mnt_opt); 576 crfree(mp->mnt_cred); 577 uma_zfree(mount_zone, mp); 578} 579 580static int 581vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 582{ 583 struct vfsoptlist *optlist; 584 struct vfsopt *opt, *noro_opt; 585 char *fstype, *fspath, *errmsg; 586 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 587 int has_rw, has_noro; 588 589 errmsg = NULL; 590 errmsg_len = 0; 591 errmsg_pos = -1; 592 has_rw = 0; 593 has_noro = 0; 594 595 error = vfs_buildopts(fsoptions, &optlist); 596 if (error) 597 return (error); 598 599 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 600 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 601 602 /* 603 * We need these two options before the others, 604 * and they are mandatory for any filesystem. 605 * Ensure they are NUL terminated as well. 606 */ 607 fstypelen = 0; 608 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 609 if (error || fstype[fstypelen - 1] != '\0') { 610 error = EINVAL; 611 if (errmsg != NULL) 612 strncpy(errmsg, "Invalid fstype", errmsg_len); 613 goto bail; 614 } 615 fspathlen = 0; 616 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 617 if (error || fspath[fspathlen - 1] != '\0') { 618 error = EINVAL; 619 if (errmsg != NULL) 620 strncpy(errmsg, "Invalid fspath", errmsg_len); 621 goto bail; 622 } 623 624 /* 625 * We need to see if we have the "update" option 626 * before we call vfs_domount(), since vfs_domount() has special 627 * logic based on MNT_UPDATE. This is very important 628 * when we want to update the root filesystem. 629 */ 630 TAILQ_FOREACH(opt, optlist, link) { 631 if (strcmp(opt->name, "update") == 0) 632 fsflags |= MNT_UPDATE; 633 else if (strcmp(opt->name, "async") == 0) 634 fsflags |= MNT_ASYNC; 635 else if (strcmp(opt->name, "force") == 0) 636 fsflags |= MNT_FORCE; 637 else if (strcmp(opt->name, "multilabel") == 0) 638 fsflags |= MNT_MULTILABEL; 639 else if (strcmp(opt->name, "noasync") == 0) 640 fsflags &= ~MNT_ASYNC; 641 else if (strcmp(opt->name, "noatime") == 0) 642 fsflags |= MNT_NOATIME; 643 else if (strcmp(opt->name, "noclusterr") == 0) 644 fsflags |= MNT_NOCLUSTERR; 645 else if (strcmp(opt->name, "noclusterw") == 0) 646 fsflags |= MNT_NOCLUSTERW; 647 else if (strcmp(opt->name, "noexec") == 0) 648 fsflags |= MNT_NOEXEC; 649 else if (strcmp(opt->name, "nosuid") == 0) 650 fsflags |= MNT_NOSUID; 651 else if (strcmp(opt->name, "nosymfollow") == 0) 652 fsflags |= MNT_NOSYMFOLLOW; 653 else if (strcmp(opt->name, "noro") == 0) { 654 fsflags &= ~MNT_RDONLY; 655 has_noro = 1; 656 } 657 else if (strcmp(opt->name, "rw") == 0) { 658 fsflags &= ~MNT_RDONLY; 659 has_rw = 1; 660 } 661 else if (strcmp(opt->name, "ro") == 0 || 662 strcmp(opt->name, "rdonly") == 0) 663 fsflags |= MNT_RDONLY; 664 else if (strcmp(opt->name, "snapshot") == 0) 665 fsflags |= MNT_SNAPSHOT; 666 else if (strcmp(opt->name, "suiddir") == 0) 667 fsflags |= MNT_SUIDDIR; 668 else if (strcmp(opt->name, "sync") == 0) 669 fsflags |= MNT_SYNCHRONOUS; 670 else if (strcmp(opt->name, "union") == 0) 671 fsflags |= MNT_UNION; 672 } 673 674 /* 675 * If "rw" was specified as a mount option, and we 676 * are trying to update a mount-point from "ro" to "rw", 677 * we need a mount option "noro", since in vfs_mergeopts(), 678 * "noro" will cancel "ro", but "rw" will not do anything. 679 */ 680 if (has_rw && !has_noro) { 681 noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 682 noro_opt->name = strdup("noro", M_MOUNT); 683 noro_opt->value = NULL; 684 noro_opt->len = 0; 685 TAILQ_INSERT_TAIL(optlist, noro_opt, link); 686 } 687 688 /* 689 * Be ultra-paranoid about making sure the type and fspath 690 * variables will fit in our mp buffers, including the 691 * terminating NUL. 692 */ 693 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 694 error = ENAMETOOLONG; 695 goto bail; 696 } 697 698 mtx_lock(&Giant); 699 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 700 mtx_unlock(&Giant); 701bail: 702 /* copyout the errmsg */ 703 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 704 && errmsg_len > 0 && errmsg != NULL) { 705 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 706 bcopy(errmsg, 707 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 708 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 709 } else { 710 copyout(errmsg, 711 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 712 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 713 } 714 } 715 716 if (error != 0) 717 vfs_freeopts(optlist); 718 return (error); 719} 720 721/* 722 * Old mount API. 723 */ 724#ifndef _SYS_SYSPROTO_H_ 725struct mount_args { 726 char *type; 727 char *path; 728 int flags; 729 caddr_t data; 730}; 731#endif 732/* ARGSUSED */ 733int 734mount(td, uap) 735 struct thread *td; 736 struct mount_args /* { 737 char *type; 738 char *path; 739 int flags; 740 caddr_t data; 741 } */ *uap; 742{ 743 char *fstype; 744 struct vfsconf *vfsp = NULL; 745 struct mntarg *ma = NULL; 746 int error; 747 748 AUDIT_ARG(fflags, uap->flags); 749 750 /* Kick out MNT_ROOTFS early as it is legal internally */ 751 uap->flags &= ~MNT_ROOTFS; 752 753 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 754 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 755 if (error) { 756 free(fstype, M_TEMP); 757 return (error); 758 } 759 760 AUDIT_ARG(text, fstype); 761 mtx_lock(&Giant); 762 vfsp = vfs_byname_kld(fstype, td, &error); 763 free(fstype, M_TEMP); 764 if (vfsp == NULL) { 765 mtx_unlock(&Giant); 766 return (ENOENT); 767 } 768 if (vfsp->vfc_vfsops->vfs_cmount == NULL) { 769 mtx_unlock(&Giant); 770 return (EOPNOTSUPP); 771 } 772 773 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 774 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 775 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 776 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 777 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 778 779 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 780 mtx_unlock(&Giant); 781 return (error); 782} 783 784 785/* 786 * vfs_domount(): actually attempt a filesystem mount. 787 */ 788static int 789vfs_domount( 790 struct thread *td, /* Calling thread. */ 791 const char *fstype, /* Filesystem type. */ 792 char *fspath, /* Mount path. */ 793 int fsflags, /* Flags common to all filesystems. */ 794 void *fsdata /* Options local to the filesystem. */ 795 ) 796{ 797 struct vnode *vp; 798 struct mount *mp; 799 struct vfsconf *vfsp; 800 struct export_args export; 801 int error, flag = 0; 802 struct vattr va; 803 struct nameidata nd; 804 805 mtx_assert(&Giant, MA_OWNED); 806 /* 807 * Be ultra-paranoid about making sure the type and fspath 808 * variables will fit in our mp buffers, including the 809 * terminating NUL. 810 */ 811 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 812 return (ENAMETOOLONG); 813 814 if (jailed(td->td_ucred) || usermount == 0) { 815 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 816 return (error); 817 } 818 819 /* 820 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 821 */ 822 if (fsflags & MNT_EXPORTED) { 823 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 824 if (error) 825 return (error); 826 } 827 if (fsflags & MNT_SUIDDIR) { 828 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 829 if (error) 830 return (error); 831 } 832 /* 833 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 834 */ 835 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 836 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 837 fsflags |= MNT_NOSUID | MNT_USER; 838 } 839 840 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 841 vfsp = NULL; 842 if ((fsflags & MNT_UPDATE) == 0) { 843 /* Don't try to load KLDs if we're mounting the root. */ 844 if (fsflags & MNT_ROOTFS) 845 vfsp = vfs_byname(fstype); 846 else 847 vfsp = vfs_byname_kld(fstype, td, &error); 848 if (vfsp == NULL) 849 return (ENODEV); 850 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL)) 851 return (EPERM); 852 } 853 /* 854 * Get vnode to be covered 855 */ 856 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE, 857 fspath, td); 858 if ((error = namei(&nd)) != 0) 859 return (error); 860 NDFREE(&nd, NDF_ONLY_PNBUF); 861 vp = nd.ni_vp; 862 if (fsflags & MNT_UPDATE) { 863 if ((vp->v_vflag & VV_ROOT) == 0) { 864 vput(vp); 865 return (EINVAL); 866 } 867 mp = vp->v_mount; 868 vfsp = mp->mnt_vfc; 869 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL)) { 870 vput(vp); 871 return (EPERM); 872 } 873 MNT_ILOCK(mp); 874 flag = mp->mnt_flag; 875 /* 876 * We only allow the filesystem to be reloaded if it 877 * is currently mounted read-only. 878 */ 879 if ((fsflags & MNT_RELOAD) && 880 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 881 MNT_IUNLOCK(mp); 882 vput(vp); 883 return (EOPNOTSUPP); /* Needs translation */ 884 } 885 MNT_IUNLOCK(mp); 886 /* 887 * Only privileged root, or (if MNT_USER is set) the user that 888 * did the original mount is permitted to update it. 889 */ 890 error = vfs_suser(mp, td); 891 if (error) { 892 vput(vp); 893 return (error); 894 } 895 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 896 vput(vp); 897 return (EBUSY); 898 } 899 VI_LOCK(vp); 900 if ((vp->v_iflag & VI_MOUNT) != 0 || 901 vp->v_mountedhere != NULL) { 902 VI_UNLOCK(vp); 903 vfs_unbusy(mp, td); 904 vput(vp); 905 return (EBUSY); 906 } 907 vp->v_iflag |= VI_MOUNT; 908 VI_UNLOCK(vp); 909 MNT_ILOCK(mp); 910 mp->mnt_flag |= fsflags & 911 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 912 MNT_IUNLOCK(mp); 913 VOP_UNLOCK(vp, 0, td); 914 mp->mnt_optnew = fsdata; 915 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 916 } else { 917 /* 918 * If the user is not root, ensure that they own the directory 919 * onto which we are attempting to mount. 920 */ 921 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 922 if (error) { 923 vput(vp); 924 return (error); 925 } 926 if (va.va_uid != td->td_ucred->cr_uid) { 927 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 928 SUSER_ALLOWJAIL); 929 if (error) { 930 vput(vp); 931 return (error); 932 } 933 } 934 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 935 if (error != 0) { 936 vput(vp); 937 return (error); 938 } 939 if (vp->v_type != VDIR) { 940 vput(vp); 941 return (ENOTDIR); 942 } 943 VI_LOCK(vp); 944 if ((vp->v_iflag & VI_MOUNT) != 0 || 945 vp->v_mountedhere != NULL) { 946 VI_UNLOCK(vp); 947 vput(vp); 948 return (EBUSY); 949 } 950 vp->v_iflag |= VI_MOUNT; 951 VI_UNLOCK(vp); 952 953 /* 954 * Allocate and initialize the filesystem. 955 */ 956 mp = vfs_mount_alloc(vp, vfsp, fspath, td); 957 VOP_UNLOCK(vp, 0, td); 958 959 /* XXXMAC: pass to vfs_mount_alloc? */ 960 mp->mnt_optnew = fsdata; 961 } 962 963 /* 964 * Set the mount level flags. 965 */ 966 MNT_ILOCK(mp); 967 mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) | 968 (fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS | 969 MNT_RDONLY)); 970 if ((mp->mnt_flag & MNT_ASYNC) == 0) 971 mp->mnt_kern_flag &= ~MNTK_ASYNC; 972 MNT_IUNLOCK(mp); 973 /* 974 * Mount the filesystem. 975 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 976 * get. No freeing of cn_pnbuf. 977 */ 978 error = VFS_MOUNT(mp, td); 979 980 /* 981 * Process the export option only if we are 982 * updating mount options. 983 */ 984 if (!error && (fsflags & MNT_UPDATE)) { 985 if (vfs_copyopt(mp->mnt_optnew, "export", &export, 986 sizeof(export)) == 0) 987 error = vfs_export(mp, &export); 988 } 989 990 if (!error) { 991 if (mp->mnt_opt != NULL) 992 vfs_freeopts(mp->mnt_opt); 993 mp->mnt_opt = mp->mnt_optnew; 994 (void)VFS_STATFS(mp, &mp->mnt_stat, td); 995 } 996 /* 997 * Prevent external consumers of mount options from reading 998 * mnt_optnew. 999 */ 1000 mp->mnt_optnew = NULL; 1001 if (mp->mnt_flag & MNT_UPDATE) { 1002 MNT_ILOCK(mp); 1003 if (error) 1004 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | 1005 (flag & ~MNT_QUOTA); 1006 else 1007 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | 1008 MNT_FORCE | MNT_SNAPSHOT); 1009 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1010 mp->mnt_kern_flag |= MNTK_ASYNC; 1011 else 1012 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1013 MNT_IUNLOCK(mp); 1014 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1015 if (mp->mnt_syncer == NULL) 1016 error = vfs_allocate_syncvnode(mp); 1017 } else { 1018 if (mp->mnt_syncer != NULL) 1019 vrele(mp->mnt_syncer); 1020 mp->mnt_syncer = NULL; 1021 } 1022 vfs_unbusy(mp, td); 1023 VI_LOCK(vp); 1024 vp->v_iflag &= ~VI_MOUNT; 1025 VI_UNLOCK(vp); 1026 vrele(vp); 1027 return (error); 1028 } 1029 MNT_ILOCK(mp); 1030 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1031 mp->mnt_kern_flag |= MNTK_ASYNC; 1032 else 1033 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1034 MNT_IUNLOCK(mp); 1035 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1036 /* 1037 * Put the new filesystem on the mount list after root. 1038 */ 1039 cache_purge(vp); 1040 if (!error) { 1041 struct vnode *newdp; 1042 1043 VI_LOCK(vp); 1044 vp->v_iflag &= ~VI_MOUNT; 1045 VI_UNLOCK(vp); 1046 vp->v_mountedhere = mp; 1047 mtx_lock(&mountlist_mtx); 1048 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1049 mtx_unlock(&mountlist_mtx); 1050 vfs_event_signal(NULL, VQ_MOUNT, 0); 1051 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 1052 panic("mount: lost mount"); 1053 mountcheckdirs(vp, newdp); 1054 vput(newdp); 1055 VOP_UNLOCK(vp, 0, td); 1056 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1057 error = vfs_allocate_syncvnode(mp); 1058 vfs_unbusy(mp, td); 1059 if (error) 1060 vrele(vp); 1061 } else { 1062 VI_LOCK(vp); 1063 vp->v_iflag &= ~VI_MOUNT; 1064 VI_UNLOCK(vp); 1065 vfs_unbusy(mp, td); 1066 vfs_mount_destroy(mp); 1067 vput(vp); 1068 } 1069 return (error); 1070} 1071 1072/* 1073 * Unmount a filesystem. 1074 * 1075 * Note: unmount takes a path to the vnode mounted on as argument, not 1076 * special file (as before). 1077 */ 1078#ifndef _SYS_SYSPROTO_H_ 1079struct unmount_args { 1080 char *path; 1081 int flags; 1082}; 1083#endif 1084/* ARGSUSED */ 1085int 1086unmount(td, uap) 1087 struct thread *td; 1088 register struct unmount_args /* { 1089 char *path; 1090 int flags; 1091 } */ *uap; 1092{ 1093 struct mount *mp; 1094 char *pathbuf; 1095 int error, id0, id1; 1096 1097 if (jailed(td->td_ucred) || usermount == 0) { 1098 error = priv_check(td, PRIV_VFS_UNMOUNT); 1099 if (error) 1100 return (error); 1101 } 1102 1103 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1104 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1105 if (error) { 1106 free(pathbuf, M_TEMP); 1107 return (error); 1108 } 1109 AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1); 1110 mtx_lock(&Giant); 1111 if (uap->flags & MNT_BYFSID) { 1112 /* Decode the filesystem ID. */ 1113 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1114 mtx_unlock(&Giant); 1115 free(pathbuf, M_TEMP); 1116 return (EINVAL); 1117 } 1118 1119 mtx_lock(&mountlist_mtx); 1120 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1121 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1122 mp->mnt_stat.f_fsid.val[1] == id1) 1123 break; 1124 } 1125 mtx_unlock(&mountlist_mtx); 1126 } else { 1127 mtx_lock(&mountlist_mtx); 1128 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1129 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1130 break; 1131 } 1132 mtx_unlock(&mountlist_mtx); 1133 } 1134 free(pathbuf, M_TEMP); 1135 if (mp == NULL) { 1136 /* 1137 * Previously we returned ENOENT for a nonexistent path and 1138 * EINVAL for a non-mountpoint. We cannot tell these apart 1139 * now, so in the !MNT_BYFSID case return the more likely 1140 * EINVAL for compatibility. 1141 */ 1142 mtx_unlock(&Giant); 1143 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1144 } 1145 1146 /* 1147 * Don't allow unmounting the root filesystem. 1148 */ 1149 if (mp->mnt_flag & MNT_ROOTFS) { 1150 mtx_unlock(&Giant); 1151 return (EINVAL); 1152 } 1153 error = dounmount(mp, uap->flags, td); 1154 mtx_unlock(&Giant); 1155 return (error); 1156} 1157 1158/* 1159 * Do the actual filesystem unmount. 1160 */ 1161int 1162dounmount(mp, flags, td) 1163 struct mount *mp; 1164 int flags; 1165 struct thread *td; 1166{ 1167 struct vnode *coveredvp, *fsrootvp; 1168 int error; 1169 int async_flag; 1170 int mnt_gen_r; 1171 1172 mtx_assert(&Giant, MA_OWNED); 1173 1174 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 1175 mnt_gen_r = mp->mnt_gen; 1176 VI_LOCK(coveredvp); 1177 vholdl(coveredvp); 1178 error = vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK, td); 1179 vdrop(coveredvp); 1180 /* 1181 * Check for mp being unmounted while waiting for the 1182 * covered vnode lock. 1183 */ 1184 if (error) 1185 return (error); 1186 if (coveredvp->v_mountedhere != mp || 1187 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 1188 VOP_UNLOCK(coveredvp, 0, td); 1189 return (EBUSY); 1190 } 1191 } 1192 /* 1193 * Only privileged root, or (if MNT_USER is set) the user that did the 1194 * original mount is permitted to unmount this filesystem. 1195 */ 1196 error = vfs_suser(mp, td); 1197 if (error) { 1198 if (coveredvp) 1199 VOP_UNLOCK(coveredvp, 0, td); 1200 return (error); 1201 } 1202 1203 MNT_ILOCK(mp); 1204 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1205 MNT_IUNLOCK(mp); 1206 if (coveredvp) 1207 VOP_UNLOCK(coveredvp, 0, td); 1208 return (EBUSY); 1209 } 1210 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1211 /* Allow filesystems to detect that a forced unmount is in progress. */ 1212 if (flags & MNT_FORCE) 1213 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1214 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1215 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td); 1216 if (error) { 1217 MNT_ILOCK(mp); 1218 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1219 if (mp->mnt_kern_flag & MNTK_MWAIT) 1220 wakeup(mp); 1221 MNT_IUNLOCK(mp); 1222 if (coveredvp) 1223 VOP_UNLOCK(coveredvp, 0, td); 1224 return (error); 1225 } 1226 vn_start_write(NULL, &mp, V_WAIT); 1227 1228 if (mp->mnt_flag & MNT_EXPUBLIC) 1229 vfs_setpublicfs(NULL, NULL, NULL); 1230 1231 vfs_msync(mp, MNT_WAIT); 1232 MNT_ILOCK(mp); 1233 async_flag = mp->mnt_flag & MNT_ASYNC; 1234 mp->mnt_flag &= ~MNT_ASYNC; 1235 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1236 MNT_IUNLOCK(mp); 1237 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1238 if (mp->mnt_syncer != NULL) 1239 vrele(mp->mnt_syncer); 1240 /* 1241 * For forced unmounts, move process cdir/rdir refs on the fs root 1242 * vnode to the covered vnode. For non-forced unmounts we want 1243 * such references to cause an EBUSY error. 1244 */ 1245 if ((flags & MNT_FORCE) && 1246 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1247 if (mp->mnt_vnodecovered != NULL) 1248 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 1249 if (fsrootvp == rootvnode) { 1250 vrele(rootvnode); 1251 rootvnode = NULL; 1252 } 1253 vput(fsrootvp); 1254 } 1255 if (((mp->mnt_flag & MNT_RDONLY) || 1256 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 1257 (flags & MNT_FORCE)) { 1258 error = VFS_UNMOUNT(mp, flags, td); 1259 } 1260 vn_finished_write(mp); 1261 if (error) { 1262 /* Undo cdir/rdir and rootvnode changes made above. */ 1263 if ((flags & MNT_FORCE) && 1264 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1265 if (mp->mnt_vnodecovered != NULL) 1266 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 1267 if (rootvnode == NULL) { 1268 rootvnode = fsrootvp; 1269 vref(rootvnode); 1270 } 1271 vput(fsrootvp); 1272 } 1273 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1274 (void) vfs_allocate_syncvnode(mp); 1275 MNT_ILOCK(mp); 1276 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1277 mp->mnt_flag |= async_flag; 1278 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1279 mp->mnt_kern_flag |= MNTK_ASYNC; 1280 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1281 if (mp->mnt_kern_flag & MNTK_MWAIT) 1282 wakeup(mp); 1283 MNT_IUNLOCK(mp); 1284 if (coveredvp) 1285 VOP_UNLOCK(coveredvp, 0, td); 1286 return (error); 1287 } 1288 mtx_lock(&mountlist_mtx); 1289 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1290 mtx_unlock(&mountlist_mtx); 1291 if (coveredvp != NULL) { 1292 coveredvp->v_mountedhere = NULL; 1293 vput(coveredvp); 1294 } 1295 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1296 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1297 vfs_mount_destroy(mp); 1298 return (0); 1299} 1300 1301/* 1302 * --------------------------------------------------------------------- 1303 * Mounting of root filesystem 1304 * 1305 */ 1306 1307struct root_hold_token { 1308 const char *who; 1309 LIST_ENTRY(root_hold_token) list; 1310}; 1311 1312static LIST_HEAD(, root_hold_token) root_holds = 1313 LIST_HEAD_INITIALIZER(&root_holds); 1314 1315static int root_mount_complete = 0; 1316 1317/* 1318 * Hold root mount. 1319 */ 1320struct root_hold_token * 1321root_mount_hold(const char *identifier) 1322{ 1323 struct root_hold_token *h; 1324 1325 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1326 h->who = identifier; 1327 mtx_lock(&mountlist_mtx); 1328 LIST_INSERT_HEAD(&root_holds, h, list); 1329 mtx_unlock(&mountlist_mtx); 1330 return (h); 1331} 1332 1333/* 1334 * Release root mount. 1335 */ 1336void 1337root_mount_rel(struct root_hold_token *h) 1338{ 1339 1340 mtx_lock(&mountlist_mtx); 1341 LIST_REMOVE(h, list); 1342 wakeup(&root_holds); 1343 mtx_unlock(&mountlist_mtx); 1344 free(h, M_DEVBUF); 1345} 1346 1347/* 1348 * Wait for all subsystems to release root mount. 1349 */ 1350static void 1351root_mount_prepare(void) 1352{ 1353 struct root_hold_token *h; 1354 1355 for (;;) { 1356 DROP_GIANT(); 1357 g_waitidle(); 1358 PICKUP_GIANT(); 1359 mtx_lock(&mountlist_mtx); 1360 if (LIST_EMPTY(&root_holds)) { 1361 mtx_unlock(&mountlist_mtx); 1362 break; 1363 } 1364 printf("Root mount waiting for:"); 1365 LIST_FOREACH(h, &root_holds, list) 1366 printf(" %s", h->who); 1367 printf("\n"); 1368 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1369 hz); 1370 } 1371} 1372 1373/* 1374 * Root was mounted, share the good news. 1375 */ 1376static void 1377root_mount_done(void) 1378{ 1379 1380 mtx_lock(&mountlist_mtx); 1381 root_mount_complete = 1; 1382 wakeup(&root_mount_complete); 1383 mtx_unlock(&mountlist_mtx); 1384} 1385 1386 /* 1387 * Return true if root is already mounted. 1388 */ 1389int 1390root_mounted(void) 1391{ 1392 int mounted; 1393 1394 mtx_lock(&mountlist_mtx); 1395 mounted = root_mount_complete; 1396 mtx_unlock(&mountlist_mtx); 1397 return (mounted); 1398} 1399 1400/* 1401 * Wait until root is mounted. 1402 */ 1403void 1404root_mount_wait(void) 1405{ 1406 1407 /* 1408 * Panic on an obvious deadlock - the function can't be called from 1409 * a thread which is doing the whole SYSINIT stuff. 1410 */ 1411 KASSERT(curthread->td_proc->p_pid != 0, 1412 ("root_mount_wait: cannot be called from the swapper thread")); 1413 mtx_lock(&mountlist_mtx); 1414 while (!root_mount_complete) { 1415 msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait", 1416 hz); 1417 } 1418 mtx_unlock(&mountlist_mtx); 1419} 1420 1421static void 1422set_rootvnode(struct thread *td) 1423{ 1424 struct proc *p; 1425 1426 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1427 panic("Cannot find root vnode"); 1428 1429 p = td->td_proc; 1430 FILEDESC_SLOCK(p->p_fd); 1431 1432 if (p->p_fd->fd_cdir != NULL) 1433 vrele(p->p_fd->fd_cdir); 1434 p->p_fd->fd_cdir = rootvnode; 1435 VREF(rootvnode); 1436 1437 if (p->p_fd->fd_rdir != NULL) 1438 vrele(p->p_fd->fd_rdir); 1439 p->p_fd->fd_rdir = rootvnode; 1440 VREF(rootvnode); 1441 1442 FILEDESC_SUNLOCK(p->p_fd); 1443 1444 VOP_UNLOCK(rootvnode, 0, td); 1445} 1446 1447/* 1448 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1449 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1450 */ 1451 1452static void 1453devfs_first(void) 1454{ 1455 struct thread *td = curthread; 1456 struct vfsoptlist *opts; 1457 struct vfsconf *vfsp; 1458 struct mount *mp = NULL; 1459 int error; 1460 1461 vfsp = vfs_byname("devfs"); 1462 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1463 if (vfsp == NULL) 1464 return; 1465 1466 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td); 1467 1468 error = VFS_MOUNT(mp, td); 1469 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1470 if (error) 1471 return; 1472 1473 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 1474 TAILQ_INIT(opts); 1475 mp->mnt_opt = opts; 1476 1477 mtx_lock(&mountlist_mtx); 1478 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1479 mtx_unlock(&mountlist_mtx); 1480 1481 set_rootvnode(td); 1482 1483 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1484 if (error) 1485 printf("kern_symlink /dev -> / returns %d\n", error); 1486} 1487 1488/* 1489 * Surgically move our devfs to be mounted on /dev. 1490 */ 1491 1492static void 1493devfs_fixup(struct thread *td) 1494{ 1495 struct nameidata nd; 1496 int error; 1497 struct vnode *vp, *dvp; 1498 struct mount *mp; 1499 1500 /* Remove our devfs mount from the mountlist and purge the cache */ 1501 mtx_lock(&mountlist_mtx); 1502 mp = TAILQ_FIRST(&mountlist); 1503 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1504 mtx_unlock(&mountlist_mtx); 1505 cache_purgevfs(mp); 1506 1507 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1508 VI_LOCK(dvp); 1509 dvp->v_iflag &= ~VI_MOUNT; 1510 dvp->v_mountedhere = NULL; 1511 VI_UNLOCK(dvp); 1512 1513 /* Set up the real rootvnode, and purge the cache */ 1514 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1515 set_rootvnode(td); 1516 cache_purgevfs(rootvnode->v_mount); 1517 1518 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1519 error = namei(&nd); 1520 if (error) { 1521 printf("Lookup of /dev for devfs, error: %d\n", error); 1522 return; 1523 } 1524 NDFREE(&nd, NDF_ONLY_PNBUF); 1525 vp = nd.ni_vp; 1526 if (vp->v_type != VDIR) { 1527 vput(vp); 1528 } 1529 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1530 if (error) { 1531 vput(vp); 1532 } 1533 cache_purge(vp); 1534 mp->mnt_vnodecovered = vp; 1535 vp->v_mountedhere = mp; 1536 mtx_lock(&mountlist_mtx); 1537 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1538 mtx_unlock(&mountlist_mtx); 1539 VOP_UNLOCK(vp, 0, td); 1540 vput(dvp); 1541 vfs_unbusy(mp, td); 1542 1543 /* Unlink the no longer needed /dev/dev -> / symlink */ 1544 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1545} 1546 1547/* 1548 * Report errors during filesystem mounting. 1549 */ 1550void 1551vfs_mount_error(struct mount *mp, const char *fmt, ...) 1552{ 1553 struct vfsoptlist *moptlist = mp->mnt_optnew; 1554 va_list ap; 1555 int error, len; 1556 char *errmsg; 1557 1558 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1559 if (error || errmsg == NULL || len <= 0) 1560 return; 1561 1562 va_start(ap, fmt); 1563 vsnprintf(errmsg, (size_t)len, fmt, ap); 1564 va_end(ap); 1565} 1566 1567/* 1568 * Find and mount the root filesystem 1569 */ 1570void 1571vfs_mountroot(void) 1572{ 1573 char *cp; 1574 int error, i, asked = 0; 1575 1576 root_mount_prepare(); 1577 1578 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), 1579 NULL, NULL, mount_init, mount_fini, 1580 UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1581 devfs_first(); 1582 1583 /* 1584 * We are booted with instructions to prompt for the root filesystem. 1585 */ 1586 if (boothowto & RB_ASKNAME) { 1587 if (!vfs_mountroot_ask()) 1588 goto mounted; 1589 asked = 1; 1590 } 1591 1592 /* 1593 * The root filesystem information is compiled in, and we are 1594 * booted with instructions to use it. 1595 */ 1596 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1597 if (!vfs_mountroot_try(ctrootdevname)) 1598 goto mounted; 1599 ctrootdevname = NULL; 1600 } 1601 1602 /* 1603 * We've been given the generic "use CDROM as root" flag. This is 1604 * necessary because one media may be used in many different 1605 * devices, so we need to search for them. 1606 */ 1607 if (boothowto & RB_CDROM) { 1608 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1609 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1610 goto mounted; 1611 } 1612 } 1613 1614 /* 1615 * Try to use the value read by the loader from /etc/fstab, or 1616 * supplied via some other means. This is the preferred 1617 * mechanism. 1618 */ 1619 cp = getenv("vfs.root.mountfrom"); 1620 if (cp != NULL) { 1621 error = vfs_mountroot_try(cp); 1622 freeenv(cp); 1623 if (!error) 1624 goto mounted; 1625 } 1626 1627 /* 1628 * Try values that may have been computed by code during boot 1629 */ 1630 if (!vfs_mountroot_try(rootdevnames[0])) 1631 goto mounted; 1632 if (!vfs_mountroot_try(rootdevnames[1])) 1633 goto mounted; 1634 1635 /* 1636 * If we (still) have a compiled-in default, try it. 1637 */ 1638 if (ctrootdevname != NULL) 1639 if (!vfs_mountroot_try(ctrootdevname)) 1640 goto mounted; 1641 /* 1642 * Everything so far has failed, prompt on the console if we haven't 1643 * already tried that. 1644 */ 1645 if (!asked) 1646 if (!vfs_mountroot_ask()) 1647 goto mounted; 1648 1649 panic("Root mount failed, startup aborted."); 1650 1651mounted: 1652 root_mount_done(); 1653} 1654 1655/* 1656 * Mount (mountfrom) as the root filesystem. 1657 */ 1658static int 1659vfs_mountroot_try(const char *mountfrom) 1660{ 1661 struct mount *mp; 1662 char *vfsname, *path; 1663 time_t timebase; 1664 int error; 1665 char patt[32]; 1666 1667 vfsname = NULL; 1668 path = NULL; 1669 mp = NULL; 1670 error = EINVAL; 1671 1672 if (mountfrom == NULL) 1673 return (error); /* don't complain */ 1674 printf("Trying to mount root from %s\n", mountfrom); 1675 1676 /* parse vfs name and path */ 1677 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1678 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1679 vfsname[0] = path[0] = 0; 1680 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1681 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1682 goto out; 1683 1684 if (path[0] == '\0') 1685 strcpy(path, ROOTNAME); 1686 1687 error = kernel_vmount( 1688 MNT_RDONLY | MNT_ROOTFS, 1689 "fstype", vfsname, 1690 "fspath", "/", 1691 "from", path, 1692 NULL); 1693 if (error == 0) { 1694 /* 1695 * We mount devfs prior to mounting the / FS, so the first 1696 * entry will typically be devfs. 1697 */ 1698 mp = TAILQ_FIRST(&mountlist); 1699 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1700 1701 /* 1702 * Iterate over all currently mounted file systems and use 1703 * the time stamp found to check and/or initialize the RTC. 1704 * Typically devfs has no time stamp and the only other FS 1705 * is the actual / FS. 1706 * Call inittodr() only once and pass it the largest of the 1707 * timestamps we encounter. 1708 */ 1709 timebase = 0; 1710 do { 1711 if (mp->mnt_time > timebase) 1712 timebase = mp->mnt_time; 1713 mp = TAILQ_NEXT(mp, mnt_list); 1714 } while (mp != NULL); 1715 inittodr(timebase); 1716 1717 devfs_fixup(curthread); 1718 } 1719out: 1720 free(path, M_MOUNT); 1721 free(vfsname, M_MOUNT); 1722 return (error); 1723} 1724 1725/* 1726 * --------------------------------------------------------------------- 1727 * Interactive root filesystem selection code. 1728 */ 1729 1730static int 1731vfs_mountroot_ask(void) 1732{ 1733 char name[128]; 1734 1735 for(;;) { 1736 printf("\nManual root filesystem specification:\n"); 1737 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1738#if defined(__amd64__) || defined(__i386__) || defined(__ia64__) 1739 printf(" eg. ufs:da0s1a\n"); 1740#else 1741 printf(" eg. ufs:/dev/da0a\n"); 1742#endif 1743 printf(" ? List valid disk boot devices\n"); 1744 printf(" <empty line> Abort manual input\n"); 1745 printf("\nmountroot> "); 1746 gets(name, sizeof(name), 1); 1747 if (name[0] == '\0') 1748 return (1); 1749 if (name[0] == '?') { 1750 printf("\nList of GEOM managed disk devices:\n "); 1751 g_dev_print(); 1752 continue; 1753 } 1754 if (!vfs_mountroot_try(name)) 1755 return (0); 1756 } 1757} 1758 1759/* 1760 * --------------------------------------------------------------------- 1761 * Functions for querying mount options/arguments from filesystems. 1762 */ 1763 1764/* 1765 * Check that no unknown options are given 1766 */ 1767int 1768vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1769{ 1770 struct vfsopt *opt; 1771 const char **t, *p; 1772 1773 TAILQ_FOREACH(opt, opts, link) { 1774 p = opt->name; 1775 if (p[0] == 'n' && p[1] == 'o') 1776 p += 2; 1777 for(t = global_opts; *t != NULL; t++) 1778 if (!strcmp(*t, p)) 1779 break; 1780 if (*t != NULL) 1781 continue; 1782 for(t = legal; *t != NULL; t++) 1783 if (!strcmp(*t, p)) 1784 break; 1785 if (*t != NULL) 1786 continue; 1787 printf("mount option <%s> is unknown\n", p); 1788 return (EINVAL); 1789 } 1790 return (0); 1791} 1792 1793/* 1794 * Get a mount option by its name. 1795 * 1796 * Return 0 if the option was found, ENOENT otherwise. 1797 * If len is non-NULL it will be filled with the length 1798 * of the option. If buf is non-NULL, it will be filled 1799 * with the address of the option. 1800 */ 1801int 1802vfs_getopt(opts, name, buf, len) 1803 struct vfsoptlist *opts; 1804 const char *name; 1805 void **buf; 1806 int *len; 1807{ 1808 struct vfsopt *opt; 1809 1810 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1811 1812 TAILQ_FOREACH(opt, opts, link) { 1813 if (strcmp(name, opt->name) == 0) { 1814 if (len != NULL) 1815 *len = opt->len; 1816 if (buf != NULL) 1817 *buf = opt->value; 1818 return (0); 1819 } 1820 } 1821 return (ENOENT); 1822} 1823 1824static int 1825vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1826{ 1827 struct vfsopt *opt; 1828 int i; 1829 1830 if (opts == NULL) 1831 return (-1); 1832 1833 i = 0; 1834 TAILQ_FOREACH(opt, opts, link) { 1835 if (strcmp(name, opt->name) == 0) 1836 return (i); 1837 ++i; 1838 } 1839 return (-1); 1840} 1841 1842char * 1843vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1844{ 1845 struct vfsopt *opt; 1846 1847 *error = 0; 1848 TAILQ_FOREACH(opt, opts, link) { 1849 if (strcmp(name, opt->name) != 0) 1850 continue; 1851 if (((char *)opt->value)[opt->len - 1] != '\0') { 1852 *error = EINVAL; 1853 return (NULL); 1854 } 1855 return (opt->value); 1856 } 1857 *error = ENOENT; 1858 return (NULL); 1859} 1860 1861int 1862vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1863{ 1864 struct vfsopt *opt; 1865 1866 TAILQ_FOREACH(opt, opts, link) { 1867 if (strcmp(name, opt->name) == 0) { 1868 if (w != NULL) 1869 *w |= val; 1870 return (1); 1871 } 1872 } 1873 if (w != NULL) 1874 *w &= ~val; 1875 return (0); 1876} 1877 1878int 1879vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1880{ 1881 va_list ap; 1882 struct vfsopt *opt; 1883 int ret; 1884 1885 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1886 1887 TAILQ_FOREACH(opt, opts, link) { 1888 if (strcmp(name, opt->name) != 0) 1889 continue; 1890 if (((char *)opt->value)[opt->len - 1] != '\0') 1891 return (0); 1892 va_start(ap, fmt); 1893 ret = vsscanf(opt->value, fmt, ap); 1894 va_end(ap); 1895 return (ret); 1896 } 1897 return (0); 1898} 1899 1900/* 1901 * Find and copy a mount option. 1902 * 1903 * The size of the buffer has to be specified 1904 * in len, if it is not the same length as the 1905 * mount option, EINVAL is returned. 1906 * Returns ENOENT if the option is not found. 1907 */ 1908int 1909vfs_copyopt(opts, name, dest, len) 1910 struct vfsoptlist *opts; 1911 const char *name; 1912 void *dest; 1913 int len; 1914{ 1915 struct vfsopt *opt; 1916 1917 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1918 1919 TAILQ_FOREACH(opt, opts, link) { 1920 if (strcmp(name, opt->name) == 0) { 1921 if (len != opt->len) 1922 return (EINVAL); 1923 bcopy(opt->value, dest, opt->len); 1924 return (0); 1925 } 1926 } 1927 return (ENOENT); 1928} 1929 1930/* 1931 * This is a helper function for filesystems to traverse their 1932 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1933 */ 1934 1935struct vnode * 1936__mnt_vnode_next(struct vnode **mvp, struct mount *mp) 1937{ 1938 struct vnode *vp; 1939 1940 mtx_assert(MNT_MTX(mp), MA_OWNED); 1941 1942 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 1943 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 1944 while (vp != NULL && vp->v_type == VMARKER) 1945 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1946 1947 /* Check if we are done */ 1948 if (vp == NULL) { 1949 __mnt_vnode_markerfree(mvp, mp); 1950 return (NULL); 1951 } 1952 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 1953 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1954 return (vp); 1955} 1956 1957struct vnode * 1958__mnt_vnode_first(struct vnode **mvp, struct mount *mp) 1959{ 1960 struct vnode *vp; 1961 1962 mtx_assert(MNT_MTX(mp), MA_OWNED); 1963 1964 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1965 while (vp != NULL && vp->v_type == VMARKER) 1966 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1967 1968 /* Check if we are done */ 1969 if (vp == NULL) { 1970 *mvp = NULL; 1971 return (NULL); 1972 } 1973 mp->mnt_holdcnt++; 1974 MNT_IUNLOCK(mp); 1975 *mvp = (struct vnode *) malloc(sizeof(struct vnode), 1976 M_VNODE_MARKER, 1977 M_WAITOK | M_ZERO); 1978 MNT_ILOCK(mp); 1979 (*mvp)->v_type = VMARKER; 1980 1981 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1982 while (vp != NULL && vp->v_type == VMARKER) 1983 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1984 1985 /* Check if we are done */ 1986 if (vp == NULL) { 1987 MNT_IUNLOCK(mp); 1988 free(*mvp, M_VNODE_MARKER); 1989 MNT_ILOCK(mp); 1990 *mvp = NULL; 1991 mp->mnt_holdcnt--; 1992 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 1993 wakeup(&mp->mnt_holdcnt); 1994 return (NULL); 1995 } 1996 mp->mnt_markercnt++; 1997 (*mvp)->v_mount = mp; 1998 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1999 return (vp); 2000} 2001 2002 2003void 2004__mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp) 2005{ 2006 2007 if (*mvp == NULL) 2008 return; 2009 2010 mtx_assert(MNT_MTX(mp), MA_OWNED); 2011 2012 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 2013 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 2014 MNT_IUNLOCK(mp); 2015 free(*mvp, M_VNODE_MARKER); 2016 MNT_ILOCK(mp); 2017 *mvp = NULL; 2018 2019 mp->mnt_markercnt--; 2020 mp->mnt_holdcnt--; 2021 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 2022 wakeup(&mp->mnt_holdcnt); 2023} 2024 2025 2026int 2027__vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 2028{ 2029 int error; 2030 2031 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 2032 if (sbp != &mp->mnt_stat) 2033 *sbp = mp->mnt_stat; 2034 return (error); 2035} 2036 2037void 2038vfs_mountedfrom(struct mount *mp, const char *from) 2039{ 2040 2041 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2042 strlcpy(mp->mnt_stat.f_mntfromname, from, 2043 sizeof mp->mnt_stat.f_mntfromname); 2044} 2045 2046/* 2047 * --------------------------------------------------------------------- 2048 * This is the api for building mount args and mounting filesystems from 2049 * inside the kernel. 2050 * 2051 * The API works by accumulation of individual args. First error is 2052 * latched. 2053 * 2054 * XXX: should be documented in new manpage kernel_mount(9) 2055 */ 2056 2057/* A memory allocation which must be freed when we are done */ 2058struct mntaarg { 2059 SLIST_ENTRY(mntaarg) next; 2060}; 2061 2062/* The header for the mount arguments */ 2063struct mntarg { 2064 struct iovec *v; 2065 int len; 2066 int error; 2067 SLIST_HEAD(, mntaarg) list; 2068}; 2069 2070/* 2071 * Add a boolean argument. 2072 * 2073 * flag is the boolean value. 2074 * name must start with "no". 2075 */ 2076struct mntarg * 2077mount_argb(struct mntarg *ma, int flag, const char *name) 2078{ 2079 2080 KASSERT(name[0] == 'n' && name[1] == 'o', 2081 ("mount_argb(...,%s): name must start with 'no'", name)); 2082 2083 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2084} 2085 2086/* 2087 * Add an argument printf style 2088 */ 2089struct mntarg * 2090mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2091{ 2092 va_list ap; 2093 struct mntaarg *maa; 2094 struct sbuf *sb; 2095 int len; 2096 2097 if (ma == NULL) { 2098 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2099 SLIST_INIT(&ma->list); 2100 } 2101 if (ma->error) 2102 return (ma); 2103 2104 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2105 M_MOUNT, M_WAITOK); 2106 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2107 ma->v[ma->len].iov_len = strlen(name) + 1; 2108 ma->len++; 2109 2110 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 2111 va_start(ap, fmt); 2112 sbuf_vprintf(sb, fmt, ap); 2113 va_end(ap); 2114 sbuf_finish(sb); 2115 len = sbuf_len(sb) + 1; 2116 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2117 SLIST_INSERT_HEAD(&ma->list, maa, next); 2118 bcopy(sbuf_data(sb), maa + 1, len); 2119 sbuf_delete(sb); 2120 2121 ma->v[ma->len].iov_base = maa + 1; 2122 ma->v[ma->len].iov_len = len; 2123 ma->len++; 2124 2125 return (ma); 2126} 2127 2128/* 2129 * Add an argument which is a userland string. 2130 */ 2131struct mntarg * 2132mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2133{ 2134 struct mntaarg *maa; 2135 char *tbuf; 2136 2137 if (val == NULL) 2138 return (ma); 2139 if (ma == NULL) { 2140 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2141 SLIST_INIT(&ma->list); 2142 } 2143 if (ma->error) 2144 return (ma); 2145 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2146 SLIST_INSERT_HEAD(&ma->list, maa, next); 2147 tbuf = (void *)(maa + 1); 2148 ma->error = copyinstr(val, tbuf, len, NULL); 2149 return (mount_arg(ma, name, tbuf, -1)); 2150} 2151 2152/* 2153 * Plain argument. 2154 * 2155 * If length is -1, use printf. 2156 */ 2157struct mntarg * 2158mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2159{ 2160 2161 if (ma == NULL) { 2162 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2163 SLIST_INIT(&ma->list); 2164 } 2165 if (ma->error) 2166 return (ma); 2167 2168 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2169 M_MOUNT, M_WAITOK); 2170 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2171 ma->v[ma->len].iov_len = strlen(name) + 1; 2172 ma->len++; 2173 2174 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2175 if (len < 0) 2176 ma->v[ma->len].iov_len = strlen(val) + 1; 2177 else 2178 ma->v[ma->len].iov_len = len; 2179 ma->len++; 2180 return (ma); 2181} 2182 2183/* 2184 * Free a mntarg structure 2185 */ 2186static void 2187free_mntarg(struct mntarg *ma) 2188{ 2189 struct mntaarg *maa; 2190 2191 while (!SLIST_EMPTY(&ma->list)) { 2192 maa = SLIST_FIRST(&ma->list); 2193 SLIST_REMOVE_HEAD(&ma->list, next); 2194 free(maa, M_MOUNT); 2195 } 2196 free(ma->v, M_MOUNT); 2197 free(ma, M_MOUNT); 2198} 2199 2200/* 2201 * Mount a filesystem 2202 */ 2203int 2204kernel_mount(struct mntarg *ma, int flags) 2205{ 2206 struct uio auio; 2207 int error; 2208 2209 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2210 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2211 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2212 2213 auio.uio_iov = ma->v; 2214 auio.uio_iovcnt = ma->len; 2215 auio.uio_segflg = UIO_SYSSPACE; 2216 2217 error = ma->error; 2218 if (!error) 2219 error = vfs_donmount(curthread, flags, &auio); 2220 free_mntarg(ma); 2221 return (error); 2222} 2223 2224/* 2225 * A printflike function to mount a filesystem. 2226 */ 2227int 2228kernel_vmount(int flags, ...) 2229{ 2230 struct mntarg *ma = NULL; 2231 va_list ap; 2232 const char *cp; 2233 const void *vp; 2234 int error; 2235 2236 va_start(ap, flags); 2237 for (;;) { 2238 cp = va_arg(ap, const char *); 2239 if (cp == NULL) 2240 break; 2241 vp = va_arg(ap, const void *); 2242 ma = mount_arg(ma, cp, vp, -1); 2243 } 2244 va_end(ap); 2245 2246 error = kernel_mount(ma, flags); 2247 return (error); 2248} 2249