Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mount.c
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1 /*- 2 * Copyright (c) 1999-2004 Poul-Henning Kamp 3 * Copyright (c) 1999 Michael Smith 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/7.4/sys/kern/vfs_mount.c 198244 2009-10-19 19:11:00Z gallatin $"); 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 81 static int vfs_domount(struct thread *td, const char *fstype, 82 char *fspath, int fsflags, void *fsdata); 83 static int vfs_mountroot_ask(void); 84 static int vfs_mountroot_try(const char *mountfrom); 85 static void free_mntarg(struct mntarg *ma); 86 static int vfs_getopt_pos(struct vfsoptlist *opts, const char *name); 87 88 static int usermount = 0; 89 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 90 "Unprivileged users may mount and unmount file systems"); 91 92 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 93 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 94 static uma_zone_t mount_zone; 95 96 /* List of mounted filesystems. */ 97 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 98 99 /* For any iteration/modification of mountlist */ 100 struct mtx mountlist_mtx; 101 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 102 103 /* 104 * The vnode of the system's root (/ in the filesystem, without chroot 105 * active.) 106 */ 107 struct vnode *rootvnode; 108 109 /* 110 * The root filesystem is detailed in the kernel environment variable 111 * vfs.root.mountfrom, which is expected to be in the general format 112 * 113 * <vfsname>:[<path>] 114 * vfsname := the name of a VFS known to the kernel and capable 115 * of being mounted as root 116 * path := disk device name or other data used by the filesystem 117 * to locate its physical store 118 */ 119 120 /* 121 * Global opts, taken by all filesystems 122 */ 123 static const char *global_opts[] = { 124 "errmsg", 125 "fstype", 126 "fspath", 127 "ro", 128 "rw", 129 "nosuid", 130 "noexec", 131 NULL 132 }; 133 134 /* 135 * The root specifiers we will try if RB_CDROM is specified. 136 */ 137 static char *cdrom_rootdevnames[] = { 138 "cd9660:cd0", 139 "cd9660:acd0", 140 NULL 141 }; 142 143 /* legacy find-root code */ 144 char *rootdevnames[2] = {NULL, NULL}; 145 #ifndef ROOTDEVNAME 146 # define ROOTDEVNAME NULL 147 #endif 148 static const char *ctrootdevname = ROOTDEVNAME; 149 150 /* 151 * --------------------------------------------------------------------- 152 * Functions for building and sanitizing the mount options 153 */ 154 155 /* Remove one mount option. */ 156 static void 157 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 158 { 159 160 TAILQ_REMOVE(opts, opt, link); 161 free(opt->name, M_MOUNT); 162 if (opt->value != NULL) 163 free(opt->value, M_MOUNT); 164 #ifdef INVARIANTS 165 else if (opt->len != 0) 166 panic("%s: mount option with NULL value but length != 0", 167 __func__); 168 #endif 169 free(opt, M_MOUNT); 170 } 171 172 /* Release all resources related to the mount options. */ 173 void 174 vfs_freeopts(struct vfsoptlist *opts) 175 { 176 struct vfsopt *opt; 177 178 while (!TAILQ_EMPTY(opts)) { 179 opt = TAILQ_FIRST(opts); 180 vfs_freeopt(opts, opt); 181 } 182 free(opts, M_MOUNT); 183 } 184 185 void 186 vfs_deleteopt(struct vfsoptlist *opts, const char *name) 187 { 188 struct vfsopt *opt, *temp; 189 190 if (opts == NULL) 191 return; 192 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 193 if (strcmp(opt->name, name) == 0) 194 vfs_freeopt(opts, opt); 195 } 196 } 197 198 /* 199 * Check if options are equal (with or without the "no" prefix). 200 */ 201 static int 202 vfs_equalopts(const char *opt1, const char *opt2) 203 { 204 205 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 206 if (strcmp(opt1, opt2) == 0) 207 return (1); 208 /* "noopt" vs. "opt" */ 209 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 210 return (1); 211 /* "opt" vs. "noopt" */ 212 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 213 return (1); 214 return (0); 215 } 216 217 /* 218 * If a mount option is specified several times, 219 * (with or without the "no" prefix) only keep 220 * the last occurence of it. 221 */ 222 static void 223 vfs_sanitizeopts(struct vfsoptlist *opts) 224 { 225 struct vfsopt *opt, *opt2, *tmp; 226 227 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 228 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 229 while (opt2 != NULL) { 230 if (vfs_equalopts(opt->name, opt2->name)) { 231 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 232 vfs_freeopt(opts, opt2); 233 opt2 = tmp; 234 } else { 235 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 236 } 237 } 238 } 239 } 240 241 /* 242 * Build a linked list of mount options from a struct uio. 243 */ 244 static int 245 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 246 { 247 struct vfsoptlist *opts; 248 struct vfsopt *opt; 249 size_t memused; 250 unsigned int i, iovcnt; 251 int error, namelen, optlen; 252 253 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 254 TAILQ_INIT(opts); 255 memused = 0; 256 iovcnt = auio->uio_iovcnt; 257 for (i = 0; i < iovcnt; i += 2) { 258 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 259 namelen = auio->uio_iov[i].iov_len; 260 optlen = auio->uio_iov[i + 1].iov_len; 261 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 262 opt->value = NULL; 263 opt->len = 0; 264 265 /* 266 * Do this early, so jumps to "bad" will free the current 267 * option. 268 */ 269 TAILQ_INSERT_TAIL(opts, opt, link); 270 memused += sizeof(struct vfsopt) + optlen + namelen; 271 272 /* 273 * Avoid consuming too much memory, and attempts to overflow 274 * memused. 275 */ 276 if (memused > VFS_MOUNTARG_SIZE_MAX || 277 optlen > VFS_MOUNTARG_SIZE_MAX || 278 namelen > VFS_MOUNTARG_SIZE_MAX) { 279 error = EINVAL; 280 goto bad; 281 } 282 283 if (auio->uio_segflg == UIO_SYSSPACE) { 284 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 285 } else { 286 error = copyin(auio->uio_iov[i].iov_base, opt->name, 287 namelen); 288 if (error) 289 goto bad; 290 } 291 /* Ensure names are null-terminated strings. */ 292 if (opt->name[namelen - 1] != '\0') { 293 error = EINVAL; 294 goto bad; 295 } 296 if (optlen != 0) { 297 opt->len = optlen; 298 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 299 if (auio->uio_segflg == UIO_SYSSPACE) { 300 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 301 optlen); 302 } else { 303 error = copyin(auio->uio_iov[i + 1].iov_base, 304 opt->value, optlen); 305 if (error) 306 goto bad; 307 } 308 } 309 } 310 vfs_sanitizeopts(opts); 311 *options = opts; 312 return (0); 313 bad: 314 vfs_freeopts(opts); 315 return (error); 316 } 317 318 /* 319 * Merge the old mount options with the new ones passed 320 * in the MNT_UPDATE case. 321 */ 322 static void 323 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 324 { 325 struct vfsopt *opt, *opt2, *new; 326 327 TAILQ_FOREACH(opt, opts, link) { 328 /* 329 * Check that this option hasn't been redefined 330 * nor cancelled with a "no" mount option. 331 */ 332 opt2 = TAILQ_FIRST(toopts); 333 while (opt2 != NULL) { 334 if (strcmp(opt2->name, opt->name) == 0) 335 goto next; 336 if (strncmp(opt2->name, "no", 2) == 0 && 337 strcmp(opt2->name + 2, opt->name) == 0) { 338 vfs_freeopt(toopts, opt2); 339 goto next; 340 } 341 opt2 = TAILQ_NEXT(opt2, link); 342 } 343 /* We want this option, duplicate it. */ 344 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 345 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 346 strcpy(new->name, opt->name); 347 if (opt->len != 0) { 348 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 349 bcopy(opt->value, new->value, opt->len); 350 } else { 351 new->value = NULL; 352 } 353 new->len = opt->len; 354 TAILQ_INSERT_TAIL(toopts, new, link); 355 next: 356 continue; 357 } 358 } 359 360 /* 361 * Mount a filesystem. 362 */ 363 int 364 nmount(td, uap) 365 struct thread *td; 366 struct nmount_args /* { 367 struct iovec *iovp; 368 unsigned int iovcnt; 369 int flags; 370 } */ *uap; 371 { 372 struct uio *auio; 373 struct iovec *iov; 374 unsigned int i; 375 int error; 376 u_int iovcnt; 377 378 AUDIT_ARG(fflags, uap->flags); 379 380 /* 381 * Filter out MNT_ROOTFS. We do not want clients of nmount() in 382 * userspace to set this flag, but we must filter it out if we want 383 * MNT_UPDATE on the root file system to work. 384 * MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try(). 385 */ 386 uap->flags &= ~MNT_ROOTFS; 387 388 iovcnt = uap->iovcnt; 389 /* 390 * Check that we have an even number of iovec's 391 * and that we have at least two options. 392 */ 393 if ((iovcnt & 1) || (iovcnt < 4)) 394 return (EINVAL); 395 396 error = copyinuio(uap->iovp, iovcnt, &auio); 397 if (error) 398 return (error); 399 iov = auio->uio_iov; 400 for (i = 0; i < iovcnt; i++) { 401 if (iov->iov_len > MMAXOPTIONLEN) { 402 free(auio, M_IOV); 403 return (EINVAL); 404 } 405 iov++; 406 } 407 error = vfs_donmount(td, uap->flags, auio); 408 409 free(auio, M_IOV); 410 return (error); 411 } 412 413 /* 414 * --------------------------------------------------------------------- 415 * Various utility functions 416 */ 417 418 void 419 vfs_ref(struct mount *mp) 420 { 421 422 MNT_ILOCK(mp); 423 MNT_REF(mp); 424 MNT_IUNLOCK(mp); 425 } 426 427 void 428 vfs_rel(struct mount *mp) 429 { 430 431 MNT_ILOCK(mp); 432 MNT_REL(mp); 433 MNT_IUNLOCK(mp); 434 } 435 436 static int 437 mount_init(void *mem, int size, int flags) 438 { 439 struct mount *mp; 440 441 mp = (struct mount *)mem; 442 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 443 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 444 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0); 445 return (0); 446 } 447 448 static void 449 mount_fini(void *mem, int size) 450 { 451 struct mount *mp; 452 453 mp = (struct mount *)mem; 454 lockdestroy(&mp->mnt_explock); 455 lockdestroy(&mp->mnt_lock); 456 mtx_destroy(&mp->mnt_mtx); 457 } 458 459 /* 460 * Allocate and initialize the mount point struct. 461 */ 462 struct mount * 463 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 464 const char *fspath, struct thread *td) 465 { 466 struct mount *mp; 467 468 mp = uma_zalloc(mount_zone, M_WAITOK); 469 bzero(&mp->mnt_startzero, 470 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 471 TAILQ_INIT(&mp->mnt_nvnodelist); 472 mp->mnt_nvnodelistsize = 0; 473 mp->mnt_ref = 0; 474 (void) vfs_busy(mp, LK_NOWAIT, 0, td); 475 mp->mnt_op = vfsp->vfc_vfsops; 476 mp->mnt_vfc = vfsp; 477 vfsp->vfc_refcount++; /* XXX Unlocked */ 478 mp->mnt_stat.f_type = vfsp->vfc_typenum; 479 mp->mnt_gen++; 480 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 481 mp->mnt_vnodecovered = vp; 482 mp->mnt_cred = crdup(td->td_ucred); 483 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 484 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 485 mp->mnt_iosize_max = DFLTPHYS; 486 #ifdef MAC 487 mac_init_mount(mp); 488 mac_create_mount(td->td_ucred, mp); 489 #endif 490 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 491 return (mp); 492 } 493 494 /* 495 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 496 */ 497 void 498 vfs_mount_destroy(struct mount *mp) 499 { 500 int i; 501 502 MNT_ILOCK(mp); 503 mp->mnt_kern_flag |= MNTK_REFEXPIRE; 504 if (mp->mnt_kern_flag & MNTK_MWAIT) { 505 mp->mnt_kern_flag &= ~MNTK_MWAIT; 506 wakeup(mp); 507 } 508 for (i = 0; mp->mnt_ref && i < 3; i++) 509 msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz); 510 /* 511 * This will always cause a 3 second delay in rebooting due to 512 * refs on the root mountpoint that never go away. Most of these 513 * are held by init which never exits. 514 */ 515 if (i == 3 && (!rebooting || bootverbose)) 516 printf("Mount point %s had %d dangling refs\n", 517 mp->mnt_stat.f_mntonname, mp->mnt_ref); 518 if (mp->mnt_holdcnt != 0) { 519 printf("Waiting for mount point to be unheld\n"); 520 while (mp->mnt_holdcnt != 0) { 521 mp->mnt_holdcntwaiters++; 522 msleep(&mp->mnt_holdcnt, MNT_MTX(mp), 523 PZERO, "mntdestroy", 0); 524 mp->mnt_holdcntwaiters--; 525 } 526 printf("mount point unheld\n"); 527 } 528 if (mp->mnt_writeopcount > 0) { 529 printf("Waiting for mount point write ops\n"); 530 while (mp->mnt_writeopcount > 0) { 531 mp->mnt_kern_flag |= MNTK_SUSPEND; 532 msleep(&mp->mnt_writeopcount, 533 MNT_MTX(mp), 534 PZERO, "mntdestroy2", 0); 535 } 536 printf("mount point write ops completed\n"); 537 } 538 if (mp->mnt_secondary_writes > 0) { 539 printf("Waiting for mount point secondary write ops\n"); 540 while (mp->mnt_secondary_writes > 0) { 541 mp->mnt_kern_flag |= MNTK_SUSPEND; 542 msleep(&mp->mnt_secondary_writes, 543 MNT_MTX(mp), 544 PZERO, "mntdestroy3", 0); 545 } 546 printf("mount point secondary write ops completed\n"); 547 } 548 MNT_IUNLOCK(mp); 549 mp->mnt_vfc->vfc_refcount--; 550 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 551 struct vnode *vp; 552 553 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 554 vprint("", vp); 555 panic("unmount: dangling vnode"); 556 } 557 MNT_ILOCK(mp); 558 if (mp->mnt_kern_flag & MNTK_MWAIT) 559 wakeup(mp); 560 if (mp->mnt_writeopcount != 0) 561 panic("vfs_mount_destroy: nonzero writeopcount"); 562 if (mp->mnt_secondary_writes != 0) 563 panic("vfs_mount_destroy: nonzero secondary_writes"); 564 if (mp->mnt_nvnodelistsize != 0) 565 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 566 mp->mnt_writeopcount = -1000; 567 mp->mnt_nvnodelistsize = -1000; 568 mp->mnt_secondary_writes = -1000; 569 MNT_IUNLOCK(mp); 570 #ifdef MAC 571 mac_destroy_mount(mp); 572 #endif 573 if (mp->mnt_opt != NULL) 574 vfs_freeopts(mp->mnt_opt); 575 crfree(mp->mnt_cred); 576 uma_zfree(mount_zone, mp); 577 } 578 579 int 580 vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 581 { 582 struct vfsoptlist *optlist; 583 struct vfsopt *opt, *noro_opt, *tmp_opt; 584 char *fstype, *fspath, *errmsg; 585 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 586 int has_rw, has_noro; 587 588 errmsg = NULL; 589 errmsg_len = 0; 590 errmsg_pos = -1; 591 has_rw = 0; 592 has_noro = 0; 593 594 error = vfs_buildopts(fsoptions, &optlist); 595 if (error) 596 return (error); 597 598 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 599 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 600 601 /* 602 * We need these two options before the others, 603 * and they are mandatory for any filesystem. 604 * Ensure they are NUL terminated as well. 605 */ 606 fstypelen = 0; 607 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 608 if (error || fstype[fstypelen - 1] != '\0') { 609 error = EINVAL; 610 if (errmsg != NULL) 611 strncpy(errmsg, "Invalid fstype", errmsg_len); 612 goto bail; 613 } 614 fspathlen = 0; 615 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 616 if (error || fspath[fspathlen - 1] != '\0') { 617 error = EINVAL; 618 if (errmsg != NULL) 619 strncpy(errmsg, "Invalid fspath", errmsg_len); 620 goto bail; 621 } 622 623 /* 624 * We need to see if we have the "update" option 625 * before we call vfs_domount(), since vfs_domount() has special 626 * logic based on MNT_UPDATE. This is very important 627 * when we want to update the root filesystem. 628 */ 629 TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) { 630 if (strcmp(opt->name, "update") == 0) { 631 fsflags |= MNT_UPDATE; 632 vfs_freeopt(optlist, opt); 633 } 634 else if (strcmp(opt->name, "async") == 0) 635 fsflags |= MNT_ASYNC; 636 else if (strcmp(opt->name, "force") == 0) { 637 fsflags |= MNT_FORCE; 638 vfs_freeopt(optlist, opt); 639 } 640 else if (strcmp(opt->name, "reload") == 0) { 641 fsflags |= MNT_RELOAD; 642 vfs_freeopt(optlist, opt); 643 } 644 else if (strcmp(opt->name, "multilabel") == 0) 645 fsflags |= MNT_MULTILABEL; 646 else if (strcmp(opt->name, "noasync") == 0) 647 fsflags &= ~MNT_ASYNC; 648 else if (strcmp(opt->name, "noatime") == 0) 649 fsflags |= MNT_NOATIME; 650 else if (strcmp(opt->name, "atime") == 0) { 651 free(opt->name, M_MOUNT); 652 opt->name = strdup("nonoatime", M_MOUNT); 653 } 654 else if (strcmp(opt->name, "noclusterr") == 0) 655 fsflags |= MNT_NOCLUSTERR; 656 else if (strcmp(opt->name, "clusterr") == 0) { 657 free(opt->name, M_MOUNT); 658 opt->name = strdup("nonoclusterr", M_MOUNT); 659 } 660 else if (strcmp(opt->name, "noclusterw") == 0) 661 fsflags |= MNT_NOCLUSTERW; 662 else if (strcmp(opt->name, "clusterw") == 0) { 663 free(opt->name, M_MOUNT); 664 opt->name = strdup("nonoclusterw", M_MOUNT); 665 } 666 else if (strcmp(opt->name, "noexec") == 0) 667 fsflags |= MNT_NOEXEC; 668 else if (strcmp(opt->name, "exec") == 0) { 669 free(opt->name, M_MOUNT); 670 opt->name = strdup("nonoexec", M_MOUNT); 671 } 672 else if (strcmp(opt->name, "nosuid") == 0) 673 fsflags |= MNT_NOSUID; 674 else if (strcmp(opt->name, "suid") == 0) { 675 free(opt->name, M_MOUNT); 676 opt->name = strdup("nonosuid", M_MOUNT); 677 } 678 else if (strcmp(opt->name, "nosymfollow") == 0) 679 fsflags |= MNT_NOSYMFOLLOW; 680 else if (strcmp(opt->name, "symfollow") == 0) { 681 free(opt->name, M_MOUNT); 682 opt->name = strdup("nonosymfollow", M_MOUNT); 683 } 684 else if (strcmp(opt->name, "noro") == 0) { 685 fsflags &= ~MNT_RDONLY; 686 has_noro = 1; 687 } 688 else if (strcmp(opt->name, "rw") == 0) { 689 fsflags &= ~MNT_RDONLY; 690 has_rw = 1; 691 } 692 else if (strcmp(opt->name, "ro") == 0) 693 fsflags |= MNT_RDONLY; 694 else if (strcmp(opt->name, "rdonly") == 0) { 695 free(opt->name, M_MOUNT); 696 opt->name = strdup("ro", M_MOUNT); 697 fsflags |= MNT_RDONLY; 698 } 699 else if (strcmp(opt->name, "suiddir") == 0) 700 fsflags |= MNT_SUIDDIR; 701 else if (strcmp(opt->name, "sync") == 0) 702 fsflags |= MNT_SYNCHRONOUS; 703 else if (strcmp(opt->name, "union") == 0) 704 fsflags |= MNT_UNION; 705 } 706 707 /* 708 * If "rw" was specified as a mount option, and we 709 * are trying to update a mount-point from "ro" to "rw", 710 * we need a mount option "noro", since in vfs_mergeopts(), 711 * "noro" will cancel "ro", but "rw" will not do anything. 712 */ 713 if (has_rw && !has_noro) { 714 noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 715 noro_opt->name = strdup("noro", M_MOUNT); 716 noro_opt->value = NULL; 717 noro_opt->len = 0; 718 TAILQ_INSERT_TAIL(optlist, noro_opt, link); 719 } 720 721 /* 722 * Be ultra-paranoid about making sure the type and fspath 723 * variables will fit in our mp buffers, including the 724 * terminating NUL. 725 */ 726 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 727 error = ENAMETOOLONG; 728 goto bail; 729 } 730 731 mtx_lock(&Giant); 732 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 733 mtx_unlock(&Giant); 734 bail: 735 /* copyout the errmsg */ 736 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 737 && errmsg_len > 0 && errmsg != NULL) { 738 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 739 bcopy(errmsg, 740 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 741 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 742 } else { 743 copyout(errmsg, 744 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 745 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 746 } 747 } 748 749 if (error != 0) 750 vfs_freeopts(optlist); 751 return (error); 752 } 753 754 /* 755 * Old mount API. 756 */ 757 #ifndef _SYS_SYSPROTO_H_ 758 struct mount_args { 759 char *type; 760 char *path; 761 int flags; 762 caddr_t data; 763 }; 764 #endif 765 /* ARGSUSED */ 766 int 767 mount(td, uap) 768 struct thread *td; 769 struct mount_args /* { 770 char *type; 771 char *path; 772 int flags; 773 caddr_t data; 774 } */ *uap; 775 { 776 char *fstype; 777 struct vfsconf *vfsp = NULL; 778 struct mntarg *ma = NULL; 779 int error; 780 781 AUDIT_ARG(fflags, uap->flags); 782 783 /* 784 * Filter out MNT_ROOTFS. We do not want clients of mount() in 785 * userspace to set this flag, but we must filter it out if we want 786 * MNT_UPDATE on the root file system to work. 787 * MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try(). 788 */ 789 uap->flags &= ~MNT_ROOTFS; 790 791 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 792 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 793 if (error) { 794 free(fstype, M_TEMP); 795 return (error); 796 } 797 798 AUDIT_ARG(text, fstype); 799 mtx_lock(&Giant); 800 vfsp = vfs_byname_kld(fstype, td, &error); 801 free(fstype, M_TEMP); 802 if (vfsp == NULL) { 803 mtx_unlock(&Giant); 804 return (ENOENT); 805 } 806 if (vfsp->vfc_vfsops->vfs_cmount == NULL) { 807 mtx_unlock(&Giant); 808 return (EOPNOTSUPP); 809 } 810 811 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 812 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 813 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 814 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 815 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 816 817 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 818 mtx_unlock(&Giant); 819 return (error); 820 } 821 822 823 /* 824 * vfs_domount(): actually attempt a filesystem mount. 825 */ 826 static int 827 vfs_domount( 828 struct thread *td, /* Calling thread. */ 829 const char *fstype, /* Filesystem type. */ 830 char *fspath, /* Mount path. */ 831 int fsflags, /* Flags common to all filesystems. */ 832 void *fsdata /* Options local to the filesystem. */ 833 ) 834 { 835 struct vnode *vp; 836 struct mount *mp; 837 struct vfsconf *vfsp; 838 struct export_args export; 839 int error, flag = 0; 840 struct vattr va; 841 struct nameidata nd; 842 843 mtx_assert(&Giant, MA_OWNED); 844 /* 845 * Be ultra-paranoid about making sure the type and fspath 846 * variables will fit in our mp buffers, including the 847 * terminating NUL. 848 */ 849 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 850 return (ENAMETOOLONG); 851 852 if (jailed(td->td_ucred) || usermount == 0) { 853 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0) 854 return (error); 855 } 856 857 /* 858 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 859 */ 860 if (fsflags & MNT_EXPORTED) { 861 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED); 862 if (error) 863 return (error); 864 } 865 if (fsflags & MNT_SUIDDIR) { 866 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR); 867 if (error) 868 return (error); 869 } 870 /* 871 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users. 872 */ 873 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) { 874 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0) 875 fsflags |= MNT_NOSUID | MNT_USER; 876 } 877 878 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 879 vfsp = NULL; 880 if ((fsflags & MNT_UPDATE) == 0) { 881 /* Don't try to load KLDs if we're mounting the root. */ 882 if (fsflags & MNT_ROOTFS) 883 vfsp = vfs_byname(fstype); 884 else 885 vfsp = vfs_byname_kld(fstype, td, &error); 886 if (vfsp == NULL) 887 return (ENODEV); 888 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL)) 889 return (EPERM); 890 } 891 /* 892 * Get vnode to be covered 893 */ 894 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE, 895 fspath, td); 896 if ((error = namei(&nd)) != 0) 897 return (error); 898 NDFREE(&nd, NDF_ONLY_PNBUF); 899 vp = nd.ni_vp; 900 if (fsflags & MNT_UPDATE) { 901 if ((vp->v_vflag & VV_ROOT) == 0) { 902 vput(vp); 903 return (EINVAL); 904 } 905 mp = vp->v_mount; 906 MNT_ILOCK(mp); 907 flag = mp->mnt_flag; 908 /* 909 * We only allow the filesystem to be reloaded if it 910 * is currently mounted read-only. 911 */ 912 if ((fsflags & MNT_RELOAD) && 913 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 914 MNT_IUNLOCK(mp); 915 vput(vp); 916 return (EOPNOTSUPP); /* Needs translation */ 917 } 918 MNT_IUNLOCK(mp); 919 /* 920 * Only privileged root, or (if MNT_USER is set) the user that 921 * did the original mount is permitted to update it. 922 */ 923 error = vfs_suser(mp, td); 924 if (error) { 925 vput(vp); 926 return (error); 927 } 928 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 929 vput(vp); 930 return (EBUSY); 931 } 932 VI_LOCK(vp); 933 if ((vp->v_iflag & VI_MOUNT) != 0 || 934 vp->v_mountedhere != NULL) { 935 VI_UNLOCK(vp); 936 vfs_unbusy(mp, td); 937 vput(vp); 938 return (EBUSY); 939 } 940 vp->v_iflag |= VI_MOUNT; 941 VI_UNLOCK(vp); 942 MNT_ILOCK(mp); 943 mp->mnt_flag |= fsflags & 944 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 945 MNT_IUNLOCK(mp); 946 VOP_UNLOCK(vp, 0, td); 947 mp->mnt_optnew = fsdata; 948 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 949 } else { 950 /* 951 * If the user is not root, ensure that they own the directory 952 * onto which we are attempting to mount. 953 */ 954 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 955 if (error) { 956 vput(vp); 957 return (error); 958 } 959 if (va.va_uid != td->td_ucred->cr_uid) { 960 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN, 961 0); 962 if (error) { 963 vput(vp); 964 return (error); 965 } 966 } 967 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 968 if (error != 0) { 969 vput(vp); 970 return (error); 971 } 972 if (vp->v_type != VDIR) { 973 vput(vp); 974 return (ENOTDIR); 975 } 976 VI_LOCK(vp); 977 if ((vp->v_iflag & VI_MOUNT) != 0 || 978 vp->v_mountedhere != NULL) { 979 VI_UNLOCK(vp); 980 vput(vp); 981 return (EBUSY); 982 } 983 vp->v_iflag |= VI_MOUNT; 984 VI_UNLOCK(vp); 985 986 /* 987 * Allocate and initialize the filesystem. 988 */ 989 mp = vfs_mount_alloc(vp, vfsp, fspath, td); 990 VOP_UNLOCK(vp, 0, td); 991 992 /* XXXMAC: pass to vfs_mount_alloc? */ 993 mp->mnt_optnew = fsdata; 994 } 995 996 /* 997 * Set the mount level flags. 998 */ 999 MNT_ILOCK(mp); 1000 mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) | 1001 (fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS | 1002 MNT_RDONLY)); 1003 if ((mp->mnt_flag & MNT_ASYNC) == 0) 1004 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1005 MNT_IUNLOCK(mp); 1006 /* 1007 * Mount the filesystem. 1008 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 1009 * get. No freeing of cn_pnbuf. 1010 */ 1011 error = VFS_MOUNT(mp, td); 1012 1013 /* 1014 * Process the export option only if we are 1015 * updating mount options. 1016 */ 1017 if (!error && (fsflags & MNT_UPDATE)) { 1018 if (vfs_copyopt(mp->mnt_optnew, "export", &export, 1019 sizeof(export)) == 0) 1020 error = vfs_export(mp, &export); 1021 } 1022 1023 if (!error) { 1024 if (mp->mnt_opt != NULL) 1025 vfs_freeopts(mp->mnt_opt); 1026 mp->mnt_opt = mp->mnt_optnew; 1027 (void)VFS_STATFS(mp, &mp->mnt_stat, td); 1028 } 1029 /* 1030 * Prevent external consumers of mount options from reading 1031 * mnt_optnew. 1032 */ 1033 mp->mnt_optnew = NULL; 1034 if (mp->mnt_flag & MNT_UPDATE) { 1035 MNT_ILOCK(mp); 1036 if (error) 1037 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | 1038 (flag & ~MNT_QUOTA); 1039 else 1040 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | 1041 MNT_FORCE | MNT_SNAPSHOT); 1042 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1043 mp->mnt_kern_flag |= MNTK_ASYNC; 1044 else 1045 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1046 MNT_IUNLOCK(mp); 1047 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1048 if (mp->mnt_syncer == NULL) 1049 error = vfs_allocate_syncvnode(mp); 1050 } else { 1051 if (mp->mnt_syncer != NULL) 1052 vrele(mp->mnt_syncer); 1053 mp->mnt_syncer = NULL; 1054 } 1055 vfs_unbusy(mp, td); 1056 VI_LOCK(vp); 1057 vp->v_iflag &= ~VI_MOUNT; 1058 VI_UNLOCK(vp); 1059 vrele(vp); 1060 return (error); 1061 } 1062 MNT_ILOCK(mp); 1063 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1064 mp->mnt_kern_flag |= MNTK_ASYNC; 1065 else 1066 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1067 MNT_IUNLOCK(mp); 1068 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1069 /* 1070 * Put the new filesystem on the mount list after root. 1071 */ 1072 cache_purge(vp); 1073 if (!error) { 1074 struct vnode *newdp; 1075 1076 VI_LOCK(vp); 1077 vp->v_iflag &= ~VI_MOUNT; 1078 VI_UNLOCK(vp); 1079 vp->v_mountedhere = mp; 1080 mtx_lock(&mountlist_mtx); 1081 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1082 mtx_unlock(&mountlist_mtx); 1083 vfs_event_signal(NULL, VQ_MOUNT, 0); 1084 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 1085 panic("mount: lost mount"); 1086 VOP_UNLOCK(newdp, 0, td); 1087 VOP_UNLOCK(vp, 0, td); 1088 mountcheckdirs(vp, newdp); 1089 vrele(newdp); 1090 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1091 error = vfs_allocate_syncvnode(mp); 1092 vfs_unbusy(mp, td); 1093 if (error) 1094 vrele(vp); 1095 } else { 1096 VI_LOCK(vp); 1097 vp->v_iflag &= ~VI_MOUNT; 1098 VI_UNLOCK(vp); 1099 vfs_unbusy(mp, td); 1100 vfs_mount_destroy(mp); 1101 vput(vp); 1102 } 1103 return (error); 1104 } 1105 1106 /* 1107 * Unmount a filesystem. 1108 * 1109 * Note: unmount takes a path to the vnode mounted on as argument, not 1110 * special file (as before). 1111 */ 1112 #ifndef _SYS_SYSPROTO_H_ 1113 struct unmount_args { 1114 char *path; 1115 int flags; 1116 }; 1117 #endif 1118 /* ARGSUSED */ 1119 int 1120 unmount(td, uap) 1121 struct thread *td; 1122 register struct unmount_args /* { 1123 char *path; 1124 int flags; 1125 } */ *uap; 1126 { 1127 struct mount *mp; 1128 char *pathbuf; 1129 int error, id0, id1; 1130 1131 if (jailed(td->td_ucred) || usermount == 0) { 1132 error = priv_check(td, PRIV_VFS_UNMOUNT); 1133 if (error) 1134 return (error); 1135 } 1136 1137 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1138 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1139 if (error) { 1140 free(pathbuf, M_TEMP); 1141 return (error); 1142 } 1143 AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1); 1144 mtx_lock(&Giant); 1145 if (uap->flags & MNT_BYFSID) { 1146 /* Decode the filesystem ID. */ 1147 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1148 mtx_unlock(&Giant); 1149 free(pathbuf, M_TEMP); 1150 return (EINVAL); 1151 } 1152 1153 mtx_lock(&mountlist_mtx); 1154 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1155 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1156 mp->mnt_stat.f_fsid.val[1] == id1) 1157 break; 1158 } 1159 mtx_unlock(&mountlist_mtx); 1160 } else { 1161 mtx_lock(&mountlist_mtx); 1162 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1163 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1164 break; 1165 } 1166 mtx_unlock(&mountlist_mtx); 1167 } 1168 free(pathbuf, M_TEMP); 1169 if (mp == NULL) { 1170 /* 1171 * Previously we returned ENOENT for a nonexistent path and 1172 * EINVAL for a non-mountpoint. We cannot tell these apart 1173 * now, so in the !MNT_BYFSID case return the more likely 1174 * EINVAL for compatibility. 1175 */ 1176 mtx_unlock(&Giant); 1177 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1178 } 1179 1180 /* 1181 * Don't allow unmounting the root filesystem. 1182 */ 1183 if (mp->mnt_flag & MNT_ROOTFS) { 1184 mtx_unlock(&Giant); 1185 return (EINVAL); 1186 } 1187 error = dounmount(mp, uap->flags, td); 1188 mtx_unlock(&Giant); 1189 return (error); 1190 } 1191 1192 /* 1193 * Do the actual filesystem unmount. 1194 */ 1195 int 1196 dounmount(mp, flags, td) 1197 struct mount *mp; 1198 int flags; 1199 struct thread *td; 1200 { 1201 struct vnode *coveredvp, *fsrootvp; 1202 int error; 1203 int async_flag; 1204 int mnt_gen_r; 1205 1206 mtx_assert(&Giant, MA_OWNED); 1207 1208 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 1209 mnt_gen_r = mp->mnt_gen; 1210 VI_LOCK(coveredvp); 1211 vholdl(coveredvp); 1212 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY, td); 1213 vdrop(coveredvp); 1214 /* 1215 * Check for mp being unmounted while waiting for the 1216 * covered vnode lock. 1217 */ 1218 if (coveredvp->v_mountedhere != mp || 1219 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 1220 VOP_UNLOCK(coveredvp, 0, td); 1221 return (EBUSY); 1222 } 1223 } 1224 /* 1225 * Only privileged root, or (if MNT_USER is set) the user that did the 1226 * original mount is permitted to unmount this filesystem. 1227 */ 1228 error = vfs_suser(mp, td); 1229 if (error) { 1230 if (coveredvp) 1231 VOP_UNLOCK(coveredvp, 0, td); 1232 return (error); 1233 } 1234 1235 MNT_ILOCK(mp); 1236 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1237 MNT_IUNLOCK(mp); 1238 if (coveredvp) 1239 VOP_UNLOCK(coveredvp, 0, td); 1240 return (EBUSY); 1241 } 1242 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ; 1243 /* Allow filesystems to detect that a forced unmount is in progress. */ 1244 if (flags & MNT_FORCE) 1245 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1246 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1247 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td); 1248 if (error) { 1249 MNT_ILOCK(mp); 1250 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_NOINSMNTQ | 1251 MNTK_UNMOUNTF); 1252 if (mp->mnt_kern_flag & MNTK_MWAIT) 1253 wakeup(mp); 1254 MNT_IUNLOCK(mp); 1255 if (coveredvp) 1256 VOP_UNLOCK(coveredvp, 0, td); 1257 return (error); 1258 } 1259 vn_start_write(NULL, &mp, V_WAIT); 1260 1261 if (mp->mnt_flag & MNT_EXPUBLIC) 1262 vfs_setpublicfs(NULL, NULL, NULL); 1263 1264 vfs_msync(mp, MNT_WAIT); 1265 MNT_ILOCK(mp); 1266 async_flag = mp->mnt_flag & MNT_ASYNC; 1267 mp->mnt_flag &= ~MNT_ASYNC; 1268 mp->mnt_kern_flag &= ~MNTK_ASYNC; 1269 MNT_IUNLOCK(mp); 1270 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1271 if (mp->mnt_syncer != NULL) 1272 vrele(mp->mnt_syncer); 1273 /* 1274 * For forced unmounts, move process cdir/rdir refs on the fs root 1275 * vnode to the covered vnode. For non-forced unmounts we want 1276 * such references to cause an EBUSY error. 1277 */ 1278 if ((flags & MNT_FORCE) && 1279 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1280 if (mp->mnt_vnodecovered != NULL) 1281 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 1282 if (fsrootvp == rootvnode) { 1283 vrele(rootvnode); 1284 rootvnode = NULL; 1285 } 1286 vput(fsrootvp); 1287 } 1288 if (((mp->mnt_flag & MNT_RDONLY) || 1289 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 1290 (flags & MNT_FORCE)) { 1291 error = VFS_UNMOUNT(mp, flags, td); 1292 } 1293 vn_finished_write(mp); 1294 /* 1295 * If we failed to flush the dirty blocks for this mount point, 1296 * undo all the cdir/rdir and rootvnode changes we made above. 1297 * Unless we failed to do so because the device is reporting that 1298 * it doesn't exist anymore. 1299 */ 1300 if (error && error != ENXIO) { 1301 if ((flags & MNT_FORCE) && 1302 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1303 if (mp->mnt_vnodecovered != NULL) 1304 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 1305 if (rootvnode == NULL) { 1306 rootvnode = fsrootvp; 1307 vref(rootvnode); 1308 } 1309 vput(fsrootvp); 1310 } 1311 MNT_ILOCK(mp); 1312 mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ; 1313 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) { 1314 MNT_IUNLOCK(mp); 1315 (void) vfs_allocate_syncvnode(mp); 1316 MNT_ILOCK(mp); 1317 } 1318 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1319 mp->mnt_flag |= async_flag; 1320 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0) 1321 mp->mnt_kern_flag |= MNTK_ASYNC; 1322 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1323 if (mp->mnt_kern_flag & MNTK_MWAIT) 1324 wakeup(mp); 1325 MNT_IUNLOCK(mp); 1326 if (coveredvp) 1327 VOP_UNLOCK(coveredvp, 0, td); 1328 return (error); 1329 } 1330 mtx_lock(&mountlist_mtx); 1331 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1332 mtx_unlock(&mountlist_mtx); 1333 if (coveredvp != NULL) { 1334 coveredvp->v_mountedhere = NULL; 1335 vput(coveredvp); 1336 } 1337 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1338 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1339 vfs_mount_destroy(mp); 1340 return (0); 1341 } 1342 1343 /* 1344 * --------------------------------------------------------------------- 1345 * Mounting of root filesystem 1346 * 1347 */ 1348 1349 struct root_hold_token { 1350 const char *who; 1351 LIST_ENTRY(root_hold_token) list; 1352 }; 1353 1354 static LIST_HEAD(, root_hold_token) root_holds = 1355 LIST_HEAD_INITIALIZER(&root_holds); 1356 1357 static int root_mount_complete; 1358 1359 /* 1360 * Hold root mount. 1361 */ 1362 struct root_hold_token * 1363 root_mount_hold(const char *identifier) 1364 { 1365 struct root_hold_token *h; 1366 1367 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1368 h->who = identifier; 1369 mtx_lock(&mountlist_mtx); 1370 LIST_INSERT_HEAD(&root_holds, h, list); 1371 mtx_unlock(&mountlist_mtx); 1372 return (h); 1373 } 1374 1375 /* 1376 * Release root mount. 1377 */ 1378 void 1379 root_mount_rel(struct root_hold_token *h) 1380 { 1381 1382 mtx_lock(&mountlist_mtx); 1383 LIST_REMOVE(h, list); 1384 wakeup(&root_holds); 1385 mtx_unlock(&mountlist_mtx); 1386 free(h, M_DEVBUF); 1387 } 1388 1389 /* 1390 * Wait for all subsystems to release root mount. 1391 */ 1392 static void 1393 root_mount_prepare(void) 1394 { 1395 struct root_hold_token *h; 1396 1397 for (;;) { 1398 DROP_GIANT(); 1399 g_waitidle(); 1400 PICKUP_GIANT(); 1401 mtx_lock(&mountlist_mtx); 1402 if (LIST_EMPTY(&root_holds)) { 1403 mtx_unlock(&mountlist_mtx); 1404 break; 1405 } 1406 printf("Root mount waiting for:"); 1407 LIST_FOREACH(h, &root_holds, list) 1408 printf(" %s", h->who); 1409 printf("\n"); 1410 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1411 hz); 1412 } 1413 } 1414 1415 /* 1416 * Root was mounted, share the good news. 1417 */ 1418 static void 1419 root_mount_done(void) 1420 { 1421 1422 /* 1423 * Use a mutex to prevent the wakeup being missed and waiting for 1424 * an extra 1 second sleep. 1425 */ 1426 mtx_lock(&mountlist_mtx); 1427 root_mount_complete = 1; 1428 wakeup(&root_mount_complete); 1429 mtx_unlock(&mountlist_mtx); 1430 } 1431 1432 /* 1433 * Return true if root is already mounted. 1434 */ 1435 int 1436 root_mounted(void) 1437 { 1438 1439 /* No mutex is acquired here because int stores are atomic. */ 1440 return (root_mount_complete); 1441 } 1442 1443 /* 1444 * Wait until root is mounted. 1445 */ 1446 void 1447 root_mount_wait(void) 1448 { 1449 1450 /* 1451 * Panic on an obvious deadlock - the function can't be called from 1452 * a thread which is doing the whole SYSINIT stuff. 1453 */ 1454 KASSERT(curthread->td_proc->p_pid != 0, 1455 ("root_mount_wait: cannot be called from the swapper thread")); 1456 mtx_lock(&mountlist_mtx); 1457 while (!root_mount_complete) { 1458 msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait", 1459 hz); 1460 } 1461 mtx_unlock(&mountlist_mtx); 1462 } 1463 1464 static void 1465 set_rootvnode(struct thread *td) 1466 { 1467 struct proc *p; 1468 1469 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1470 panic("Cannot find root vnode"); 1471 1472 VOP_UNLOCK(rootvnode, 0, td); 1473 1474 p = td->td_proc; 1475 FILEDESC_XLOCK(p->p_fd); 1476 1477 if (p->p_fd->fd_cdir != NULL) 1478 vrele(p->p_fd->fd_cdir); 1479 p->p_fd->fd_cdir = rootvnode; 1480 VREF(rootvnode); 1481 1482 if (p->p_fd->fd_rdir != NULL) 1483 vrele(p->p_fd->fd_rdir); 1484 p->p_fd->fd_rdir = rootvnode; 1485 VREF(rootvnode); 1486 1487 FILEDESC_XUNLOCK(p->p_fd); 1488 1489 EVENTHANDLER_INVOKE(mountroot); 1490 } 1491 1492 /* 1493 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1494 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1495 */ 1496 1497 static void 1498 devfs_first(void) 1499 { 1500 struct thread *td = curthread; 1501 struct vfsoptlist *opts; 1502 struct vfsconf *vfsp; 1503 struct mount *mp = NULL; 1504 int error; 1505 1506 vfsp = vfs_byname("devfs"); 1507 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1508 if (vfsp == NULL) 1509 return; 1510 1511 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td); 1512 1513 error = VFS_MOUNT(mp, td); 1514 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1515 if (error) 1516 return; 1517 1518 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 1519 TAILQ_INIT(opts); 1520 mp->mnt_opt = opts; 1521 1522 mtx_lock(&mountlist_mtx); 1523 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1524 mtx_unlock(&mountlist_mtx); 1525 1526 set_rootvnode(td); 1527 1528 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1529 if (error) 1530 printf("kern_symlink /dev -> / returns %d\n", error); 1531 } 1532 1533 /* 1534 * Surgically move our devfs to be mounted on /dev. 1535 */ 1536 1537 static void 1538 devfs_fixup(struct thread *td) 1539 { 1540 struct nameidata nd; 1541 int error; 1542 struct vnode *vp, *dvp; 1543 struct mount *mp; 1544 1545 /* Remove our devfs mount from the mountlist and purge the cache */ 1546 mtx_lock(&mountlist_mtx); 1547 mp = TAILQ_FIRST(&mountlist); 1548 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1549 mtx_unlock(&mountlist_mtx); 1550 cache_purgevfs(mp); 1551 1552 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1553 VI_LOCK(dvp); 1554 dvp->v_iflag &= ~VI_MOUNT; 1555 VI_UNLOCK(dvp); 1556 dvp->v_mountedhere = NULL; 1557 1558 /* Set up the real rootvnode, and purge the cache */ 1559 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1560 set_rootvnode(td); 1561 cache_purgevfs(rootvnode->v_mount); 1562 1563 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1564 error = namei(&nd); 1565 if (error) { 1566 printf("Lookup of /dev for devfs, error: %d\n", error); 1567 return; 1568 } 1569 NDFREE(&nd, NDF_ONLY_PNBUF); 1570 vp = nd.ni_vp; 1571 if (vp->v_type != VDIR) { 1572 vput(vp); 1573 } 1574 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1575 if (error) { 1576 vput(vp); 1577 } 1578 cache_purge(vp); 1579 mp->mnt_vnodecovered = vp; 1580 vp->v_mountedhere = mp; 1581 mtx_lock(&mountlist_mtx); 1582 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1583 mtx_unlock(&mountlist_mtx); 1584 VOP_UNLOCK(vp, 0, td); 1585 vput(dvp); 1586 vfs_unbusy(mp, td); 1587 1588 /* Unlink the no longer needed /dev/dev -> / symlink */ 1589 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1590 } 1591 1592 /* 1593 * Report errors during filesystem mounting. 1594 */ 1595 void 1596 vfs_mount_error(struct mount *mp, const char *fmt, ...) 1597 { 1598 struct vfsoptlist *moptlist = mp->mnt_optnew; 1599 va_list ap; 1600 int error, len; 1601 char *errmsg; 1602 1603 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1604 if (error || errmsg == NULL || len <= 0) 1605 return; 1606 1607 va_start(ap, fmt); 1608 vsnprintf(errmsg, (size_t)len, fmt, ap); 1609 va_end(ap); 1610 } 1611 1612 /* 1613 * Find and mount the root filesystem 1614 */ 1615 void 1616 vfs_mountroot(void) 1617 { 1618 char *cp; 1619 int error, i, asked = 0; 1620 1621 root_mount_prepare(); 1622 1623 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), 1624 NULL, NULL, mount_init, mount_fini, 1625 UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1626 devfs_first(); 1627 1628 /* 1629 * We are booted with instructions to prompt for the root filesystem. 1630 */ 1631 if (boothowto & RB_ASKNAME) { 1632 if (!vfs_mountroot_ask()) 1633 goto mounted; 1634 asked = 1; 1635 } 1636 1637 /* 1638 * The root filesystem information is compiled in, and we are 1639 * booted with instructions to use it. 1640 */ 1641 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1642 if (!vfs_mountroot_try(ctrootdevname)) 1643 goto mounted; 1644 ctrootdevname = NULL; 1645 } 1646 1647 /* 1648 * We've been given the generic "use CDROM as root" flag. This is 1649 * necessary because one media may be used in many different 1650 * devices, so we need to search for them. 1651 */ 1652 if (boothowto & RB_CDROM) { 1653 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1654 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1655 goto mounted; 1656 } 1657 } 1658 1659 /* 1660 * Try to use the value read by the loader from /etc/fstab, or 1661 * supplied via some other means. This is the preferred 1662 * mechanism. 1663 */ 1664 cp = getenv("vfs.root.mountfrom"); 1665 if (cp != NULL) { 1666 error = vfs_mountroot_try(cp); 1667 freeenv(cp); 1668 if (!error) 1669 goto mounted; 1670 } 1671 1672 /* 1673 * Try values that may have been computed by code during boot 1674 */ 1675 if (!vfs_mountroot_try(rootdevnames[0])) 1676 goto mounted; 1677 if (!vfs_mountroot_try(rootdevnames[1])) 1678 goto mounted; 1679 1680 /* 1681 * If we (still) have a compiled-in default, try it. 1682 */ 1683 if (ctrootdevname != NULL) 1684 if (!vfs_mountroot_try(ctrootdevname)) 1685 goto mounted; 1686 /* 1687 * Everything so far has failed, prompt on the console if we haven't 1688 * already tried that. 1689 */ 1690 if (!asked) 1691 if (!vfs_mountroot_ask()) 1692 goto mounted; 1693 1694 panic("Root mount failed, startup aborted."); 1695 1696 mounted: 1697 root_mount_done(); 1698 } 1699 1700 /* 1701 * Mount (mountfrom) as the root filesystem. 1702 */ 1703 static int 1704 vfs_mountroot_try(const char *mountfrom) 1705 { 1706 struct mount *mp; 1707 char *vfsname, *path; 1708 time_t timebase; 1709 int error; 1710 char patt[32]; 1711 1712 vfsname = NULL; 1713 path = NULL; 1714 mp = NULL; 1715 error = EINVAL; 1716 1717 if (mountfrom == NULL) 1718 return (error); /* don't complain */ 1719 printf("Trying to mount root from %s\n", mountfrom); 1720 1721 /* parse vfs name and path */ 1722 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1723 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1724 vfsname[0] = path[0] = 0; 1725 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1726 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1727 goto out; 1728 1729 if (path[0] == '\0') 1730 strcpy(path, ROOTNAME); 1731 1732 error = kernel_vmount( 1733 MNT_RDONLY | MNT_ROOTFS, 1734 "fstype", vfsname, 1735 "fspath", "/", 1736 "from", path, 1737 NULL); 1738 if (error == 0) { 1739 /* 1740 * We mount devfs prior to mounting the / FS, so the first 1741 * entry will typically be devfs. 1742 */ 1743 mp = TAILQ_FIRST(&mountlist); 1744 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1745 1746 /* 1747 * Iterate over all currently mounted file systems and use 1748 * the time stamp found to check and/or initialize the RTC. 1749 * Typically devfs has no time stamp and the only other FS 1750 * is the actual / FS. 1751 * Call inittodr() only once and pass it the largest of the 1752 * timestamps we encounter. 1753 */ 1754 timebase = 0; 1755 do { 1756 if (mp->mnt_time > timebase) 1757 timebase = mp->mnt_time; 1758 mp = TAILQ_NEXT(mp, mnt_list); 1759 } while (mp != NULL); 1760 inittodr(timebase); 1761 1762 devfs_fixup(curthread); 1763 } 1764 out: 1765 free(path, M_MOUNT); 1766 free(vfsname, M_MOUNT); 1767 return (error); 1768 } 1769 1770 /* 1771 * --------------------------------------------------------------------- 1772 * Interactive root filesystem selection code. 1773 */ 1774 1775 static int 1776 vfs_mountroot_ask(void) 1777 { 1778 char name[128]; 1779 1780 for(;;) { 1781 printf("\nManual root filesystem specification:\n"); 1782 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1783 #if defined(__amd64__) || defined(__i386__) || defined(__ia64__) 1784 printf(" eg. ufs:da0s1a\n"); 1785 #else 1786 printf(" eg. ufs:/dev/da0a\n"); 1787 #endif 1788 printf(" ? List valid disk boot devices\n"); 1789 printf(" <empty line> Abort manual input\n"); 1790 printf("\nmountroot> "); 1791 gets(name, sizeof(name), 1); 1792 if (name[0] == '\0') 1793 return (1); 1794 if (name[0] == '?') { 1795 printf("\nList of GEOM managed disk devices:\n "); 1796 g_dev_print(); 1797 continue; 1798 } 1799 if (!vfs_mountroot_try(name)) 1800 return (0); 1801 } 1802 } 1803 1804 /* 1805 * --------------------------------------------------------------------- 1806 * Functions for querying mount options/arguments from filesystems. 1807 */ 1808 1809 /* 1810 * Check that no unknown options are given 1811 */ 1812 int 1813 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1814 { 1815 struct vfsopt *opt; 1816 char errmsg[255]; 1817 const char **t, *p, *q; 1818 int ret = 0; 1819 1820 TAILQ_FOREACH(opt, opts, link) { 1821 p = opt->name; 1822 q = NULL; 1823 if (p[0] == 'n' && p[1] == 'o') 1824 q = p + 2; 1825 for(t = global_opts; *t != NULL; t++) { 1826 if (strcmp(*t, p) == 0) 1827 break; 1828 if (q != NULL) { 1829 if (strcmp(*t, q) == 0) 1830 break; 1831 } 1832 } 1833 if (*t != NULL) 1834 continue; 1835 for(t = legal; *t != NULL; t++) { 1836 if (strcmp(*t, p) == 0) 1837 break; 1838 if (q != NULL) { 1839 if (strcmp(*t, q) == 0) 1840 break; 1841 } 1842 } 1843 if (*t != NULL) 1844 continue; 1845 snprintf(errmsg, sizeof(errmsg), 1846 "mount option <%s> is unknown", p); 1847 printf("%s\n", errmsg); 1848 ret = EINVAL; 1849 } 1850 if (ret != 0) { 1851 TAILQ_FOREACH(opt, opts, link) { 1852 if (strcmp(opt->name, "errmsg") == 0) { 1853 strncpy((char *)opt->value, errmsg, opt->len); 1854 } 1855 } 1856 } 1857 return (ret); 1858 } 1859 1860 /* 1861 * Get a mount option by its name. 1862 * 1863 * Return 0 if the option was found, ENOENT otherwise. 1864 * If len is non-NULL it will be filled with the length 1865 * of the option. If buf is non-NULL, it will be filled 1866 * with the address of the option. 1867 */ 1868 int 1869 vfs_getopt(opts, name, buf, len) 1870 struct vfsoptlist *opts; 1871 const char *name; 1872 void **buf; 1873 int *len; 1874 { 1875 struct vfsopt *opt; 1876 1877 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1878 1879 TAILQ_FOREACH(opt, opts, link) { 1880 if (strcmp(name, opt->name) == 0) { 1881 if (len != NULL) 1882 *len = opt->len; 1883 if (buf != NULL) 1884 *buf = opt->value; 1885 return (0); 1886 } 1887 } 1888 return (ENOENT); 1889 } 1890 1891 static int 1892 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1893 { 1894 struct vfsopt *opt; 1895 int i; 1896 1897 if (opts == NULL) 1898 return (-1); 1899 1900 i = 0; 1901 TAILQ_FOREACH(opt, opts, link) { 1902 if (strcmp(name, opt->name) == 0) 1903 return (i); 1904 ++i; 1905 } 1906 return (-1); 1907 } 1908 1909 char * 1910 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1911 { 1912 struct vfsopt *opt; 1913 1914 *error = 0; 1915 TAILQ_FOREACH(opt, opts, link) { 1916 if (strcmp(name, opt->name) != 0) 1917 continue; 1918 if (((char *)opt->value)[opt->len - 1] != '\0') { 1919 *error = EINVAL; 1920 return (NULL); 1921 } 1922 return (opt->value); 1923 } 1924 *error = ENOENT; 1925 return (NULL); 1926 } 1927 1928 int 1929 vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1930 { 1931 struct vfsopt *opt; 1932 1933 TAILQ_FOREACH(opt, opts, link) { 1934 if (strcmp(name, opt->name) == 0) { 1935 if (w != NULL) 1936 *w |= val; 1937 return (1); 1938 } 1939 } 1940 if (w != NULL) 1941 *w &= ~val; 1942 return (0); 1943 } 1944 1945 int 1946 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1947 { 1948 va_list ap; 1949 struct vfsopt *opt; 1950 int ret; 1951 1952 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1953 1954 TAILQ_FOREACH(opt, opts, link) { 1955 if (strcmp(name, opt->name) != 0) 1956 continue; 1957 if (opt->len == 0 || opt->value == NULL) 1958 return (0); 1959 if (((char *)opt->value)[opt->len - 1] != '\0') 1960 return (0); 1961 va_start(ap, fmt); 1962 ret = vsscanf(opt->value, fmt, ap); 1963 va_end(ap); 1964 return (ret); 1965 } 1966 return (0); 1967 } 1968 1969 /* 1970 * Find and copy a mount option. 1971 * 1972 * The size of the buffer has to be specified 1973 * in len, if it is not the same length as the 1974 * mount option, EINVAL is returned. 1975 * Returns ENOENT if the option is not found. 1976 */ 1977 int 1978 vfs_copyopt(opts, name, dest, len) 1979 struct vfsoptlist *opts; 1980 const char *name; 1981 void *dest; 1982 int len; 1983 { 1984 struct vfsopt *opt; 1985 1986 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1987 1988 TAILQ_FOREACH(opt, opts, link) { 1989 if (strcmp(name, opt->name) == 0) { 1990 if (len != opt->len) 1991 return (EINVAL); 1992 bcopy(opt->value, dest, opt->len); 1993 return (0); 1994 } 1995 } 1996 return (ENOENT); 1997 } 1998 1999 /* 2000 * This is a helper function for filesystems to traverse their 2001 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 2002 */ 2003 2004 struct vnode * 2005 __mnt_vnode_next(struct vnode **mvp, struct mount *mp) 2006 { 2007 struct vnode *vp; 2008 2009 mtx_assert(MNT_MTX(mp), MA_OWNED); 2010 2011 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 2012 if ((*mvp)->v_yield++ == 500) { 2013 MNT_IUNLOCK(mp); 2014 (*mvp)->v_yield = 0; 2015 uio_yield(); 2016 MNT_ILOCK(mp); 2017 } 2018 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 2019 while (vp != NULL && vp->v_type == VMARKER) 2020 vp = TAILQ_NEXT(vp, v_nmntvnodes); 2021 2022 /* Check if we are done */ 2023 if (vp == NULL) { 2024 __mnt_vnode_markerfree(mvp, mp); 2025 return (NULL); 2026 } 2027 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 2028 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 2029 return (vp); 2030 } 2031 2032 struct vnode * 2033 __mnt_vnode_first(struct vnode **mvp, struct mount *mp) 2034 { 2035 struct vnode *vp; 2036 2037 mtx_assert(MNT_MTX(mp), MA_OWNED); 2038 2039 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2040 while (vp != NULL && vp->v_type == VMARKER) 2041 vp = TAILQ_NEXT(vp, v_nmntvnodes); 2042 2043 /* Check if we are done */ 2044 if (vp == NULL) { 2045 *mvp = NULL; 2046 return (NULL); 2047 } 2048 mp->mnt_holdcnt++; 2049 MNT_IUNLOCK(mp); 2050 *mvp = (struct vnode *) malloc(sizeof(struct vnode), 2051 M_VNODE_MARKER, 2052 M_WAITOK | M_ZERO); 2053 MNT_ILOCK(mp); 2054 (*mvp)->v_type = VMARKER; 2055 2056 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 2057 while (vp != NULL && vp->v_type == VMARKER) 2058 vp = TAILQ_NEXT(vp, v_nmntvnodes); 2059 2060 /* Check if we are done */ 2061 if (vp == NULL) { 2062 MNT_IUNLOCK(mp); 2063 free(*mvp, M_VNODE_MARKER); 2064 MNT_ILOCK(mp); 2065 *mvp = NULL; 2066 mp->mnt_holdcnt--; 2067 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 2068 wakeup(&mp->mnt_holdcnt); 2069 return (NULL); 2070 } 2071 mp->mnt_markercnt++; 2072 (*mvp)->v_mount = mp; 2073 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 2074 return (vp); 2075 } 2076 2077 2078 void 2079 __mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp) 2080 { 2081 2082 if (*mvp == NULL) 2083 return; 2084 2085 mtx_assert(MNT_MTX(mp), MA_OWNED); 2086 2087 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 2088 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 2089 MNT_IUNLOCK(mp); 2090 free(*mvp, M_VNODE_MARKER); 2091 MNT_ILOCK(mp); 2092 *mvp = NULL; 2093 2094 mp->mnt_markercnt--; 2095 mp->mnt_holdcnt--; 2096 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 2097 wakeup(&mp->mnt_holdcnt); 2098 } 2099 2100 2101 int 2102 __vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 2103 { 2104 int error; 2105 2106 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 2107 if (sbp != &mp->mnt_stat) 2108 *sbp = mp->mnt_stat; 2109 return (error); 2110 } 2111 2112 void 2113 vfs_mountedfrom(struct mount *mp, const char *from) 2114 { 2115 2116 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 2117 strlcpy(mp->mnt_stat.f_mntfromname, from, 2118 sizeof mp->mnt_stat.f_mntfromname); 2119 } 2120 2121 /* 2122 * --------------------------------------------------------------------- 2123 * This is the api for building mount args and mounting filesystems from 2124 * inside the kernel. 2125 * 2126 * The API works by accumulation of individual args. First error is 2127 * latched. 2128 * 2129 * XXX: should be documented in new manpage kernel_mount(9) 2130 */ 2131 2132 /* A memory allocation which must be freed when we are done */ 2133 struct mntaarg { 2134 SLIST_ENTRY(mntaarg) next; 2135 }; 2136 2137 /* The header for the mount arguments */ 2138 struct mntarg { 2139 struct iovec *v; 2140 int len; 2141 int error; 2142 SLIST_HEAD(, mntaarg) list; 2143 }; 2144 2145 /* 2146 * Add a boolean argument. 2147 * 2148 * flag is the boolean value. 2149 * name must start with "no". 2150 */ 2151 struct mntarg * 2152 mount_argb(struct mntarg *ma, int flag, const char *name) 2153 { 2154 2155 KASSERT(name[0] == 'n' && name[1] == 'o', 2156 ("mount_argb(...,%s): name must start with 'no'", name)); 2157 2158 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2159 } 2160 2161 /* 2162 * Add an argument printf style 2163 */ 2164 struct mntarg * 2165 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2166 { 2167 va_list ap; 2168 struct mntaarg *maa; 2169 struct sbuf *sb; 2170 int len; 2171 2172 if (ma == NULL) { 2173 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2174 SLIST_INIT(&ma->list); 2175 } 2176 if (ma->error) 2177 return (ma); 2178 2179 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2180 M_MOUNT, M_WAITOK); 2181 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2182 ma->v[ma->len].iov_len = strlen(name) + 1; 2183 ma->len++; 2184 2185 sb = sbuf_new_auto(); 2186 va_start(ap, fmt); 2187 sbuf_vprintf(sb, fmt, ap); 2188 va_end(ap); 2189 sbuf_finish(sb); 2190 len = sbuf_len(sb) + 1; 2191 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2192 SLIST_INSERT_HEAD(&ma->list, maa, next); 2193 bcopy(sbuf_data(sb), maa + 1, len); 2194 sbuf_delete(sb); 2195 2196 ma->v[ma->len].iov_base = maa + 1; 2197 ma->v[ma->len].iov_len = len; 2198 ma->len++; 2199 2200 return (ma); 2201 } 2202 2203 /* 2204 * Add an argument which is a userland string. 2205 */ 2206 struct mntarg * 2207 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2208 { 2209 struct mntaarg *maa; 2210 char *tbuf; 2211 2212 if (val == NULL) 2213 return (ma); 2214 if (ma == NULL) { 2215 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2216 SLIST_INIT(&ma->list); 2217 } 2218 if (ma->error) 2219 return (ma); 2220 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2221 SLIST_INSERT_HEAD(&ma->list, maa, next); 2222 tbuf = (void *)(maa + 1); 2223 ma->error = copyinstr(val, tbuf, len, NULL); 2224 return (mount_arg(ma, name, tbuf, -1)); 2225 } 2226 2227 /* 2228 * Plain argument. 2229 * 2230 * If length is -1, use printf. 2231 */ 2232 struct mntarg * 2233 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2234 { 2235 2236 if (ma == NULL) { 2237 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2238 SLIST_INIT(&ma->list); 2239 } 2240 if (ma->error) 2241 return (ma); 2242 2243 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2244 M_MOUNT, M_WAITOK); 2245 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2246 ma->v[ma->len].iov_len = strlen(name) + 1; 2247 ma->len++; 2248 2249 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2250 if (len < 0) 2251 ma->v[ma->len].iov_len = strlen(val) + 1; 2252 else 2253 ma->v[ma->len].iov_len = len; 2254 ma->len++; 2255 return (ma); 2256 } 2257 2258 /* 2259 * Free a mntarg structure 2260 */ 2261 static void 2262 free_mntarg(struct mntarg *ma) 2263 { 2264 struct mntaarg *maa; 2265 2266 while (!SLIST_EMPTY(&ma->list)) { 2267 maa = SLIST_FIRST(&ma->list); 2268 SLIST_REMOVE_HEAD(&ma->list, next); 2269 free(maa, M_MOUNT); 2270 } 2271 free(ma->v, M_MOUNT); 2272 free(ma, M_MOUNT); 2273 } 2274 2275 /* 2276 * Mount a filesystem 2277 */ 2278 int 2279 kernel_mount(struct mntarg *ma, int flags) 2280 { 2281 struct uio auio; 2282 int error; 2283 2284 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2285 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2286 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2287 2288 auio.uio_iov = ma->v; 2289 auio.uio_iovcnt = ma->len; 2290 auio.uio_segflg = UIO_SYSSPACE; 2291 2292 error = ma->error; 2293 if (!error) 2294 error = vfs_donmount(curthread, flags, &auio); 2295 free_mntarg(ma); 2296 return (error); 2297 } 2298 2299 /* 2300 * A printflike function to mount a filesystem. 2301 */ 2302 int 2303 kernel_vmount(int flags, ...) 2304 { 2305 struct mntarg *ma = NULL; 2306 va_list ap; 2307 const char *cp; 2308 const void *vp; 2309 int error; 2310 2311 va_start(ap, flags); 2312 for (;;) { 2313 cp = va_arg(ap, const char *); 2314 if (cp == NULL) 2315 break; 2316 vp = va_arg(ap, const void *); 2317 ma = mount_arg(ma, cp, vp, -1); 2318 } 2319 va_end(ap); 2320 2321 error = kernel_mount(ma, flags); 2322 return (error); 2323 }
Cache object: 4707be5c7fcbccb7d1d312bb8597b47b
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