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("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/conf.h> 42 #include <sys/jail.h> 43 #include <sys/kernel.h> 44 #include <sys/libkern.h> 45 #include <sys/mac.h> 46 #include <sys/malloc.h> 47 #include <sys/mount.h> 48 #include <sys/mutex.h> 49 #include <sys/namei.h> 50 #include <sys/proc.h> 51 #include <sys/filedesc.h> 52 #include <sys/reboot.h> 53 #include <sys/syscallsubr.h> 54 #include <sys/sysproto.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/systm.h> 59 #include <sys/vnode.h> 60 #include <vm/uma.h> 61 62 #include <geom/geom.h> 63 64 #include <machine/stdarg.h> 65 66 #include <security/audit/audit.h> 67 68 #include "opt_rootdevname.h" 69 #include "opt_ddb.h" 70 #include "opt_mac.h" 71 72 #ifdef DDB 73 #include <ddb/ddb.h> 74 #endif 75 76 #define ROOTNAME "root_device" 77 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64) 78 79 static int vfs_domount(struct thread *td, const char *fstype, 80 char *fspath, int fsflags, void *fsdata); 81 static int vfs_mount_alloc(struct vnode *dvp, struct vfsconf *vfsp, 82 const char *fspath, struct thread *td, struct mount **mpp); 83 static int vfs_mountroot_ask(void); 84 static int vfs_mountroot_try(const char *mountfrom); 85 static int vfs_donmount(struct thread *td, int fsflags, 86 struct uio *fsoptions); 87 static void free_mntarg(struct mntarg *ma); 88 static void vfs_mount_destroy(struct mount *); 89 static int vfs_getopt_pos(struct vfsoptlist *opts, const char *name); 90 91 static int usermount = 0; 92 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, 93 "Unprivileged users may mount and unmount file systems"); 94 95 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 96 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker"); 97 static uma_zone_t mount_zone; 98 99 /* List of mounted filesystems. */ 100 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); 101 102 /* For any iteration/modification of mountlist */ 103 struct mtx mountlist_mtx; 104 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF); 105 106 TAILQ_HEAD(vfsoptlist, vfsopt); 107 struct vfsopt { 108 TAILQ_ENTRY(vfsopt) link; 109 char *name; 110 void *value; 111 int len; 112 }; 113 114 /* 115 * The vnode of the system's root (/ in the filesystem, without chroot 116 * active.) 117 */ 118 struct vnode *rootvnode; 119 120 /* 121 * The root filesystem is detailed in the kernel environment variable 122 * vfs.root.mountfrom, which is expected to be in the general format 123 * 124 * <vfsname>:[<path>] 125 * vfsname := the name of a VFS known to the kernel and capable 126 * of being mounted as root 127 * path := disk device name or other data used by the filesystem 128 * to locate its physical store 129 */ 130 131 /* 132 * Global opts, taken by all filesystems 133 */ 134 static const char *global_opts[] = { 135 "errmsg", 136 "fstype", 137 "fspath", 138 "rdonly", 139 "ro", 140 "rw", 141 "suid", 142 "exec", 143 "update", 144 NULL 145 }; 146 147 /* 148 * The root specifiers we will try if RB_CDROM is specified. 149 */ 150 static char *cdrom_rootdevnames[] = { 151 "cd9660:cd0", 152 "cd9660:acd0", 153 NULL 154 }; 155 156 /* legacy find-root code */ 157 char *rootdevnames[2] = {NULL, NULL}; 158 #ifndef ROOTDEVNAME 159 # define ROOTDEVNAME NULL 160 #endif 161 static const char *ctrootdevname = ROOTDEVNAME; 162 163 /* 164 * --------------------------------------------------------------------- 165 * Functions for building and sanitizing the mount options 166 */ 167 168 /* Remove one mount option. */ 169 static void 170 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt) 171 { 172 173 TAILQ_REMOVE(opts, opt, link); 174 free(opt->name, M_MOUNT); 175 if (opt->value != NULL) 176 free(opt->value, M_MOUNT); 177 #ifdef INVARIANTS 178 else if (opt->len != 0) 179 panic("%s: mount option with NULL value but length != 0", 180 __func__); 181 #endif 182 free(opt, M_MOUNT); 183 } 184 185 /* Release all resources related to the mount options. */ 186 static void 187 vfs_freeopts(struct vfsoptlist *opts) 188 { 189 struct vfsopt *opt; 190 191 while (!TAILQ_EMPTY(opts)) { 192 opt = TAILQ_FIRST(opts); 193 vfs_freeopt(opts, opt); 194 } 195 free(opts, M_MOUNT); 196 } 197 198 void 199 vfs_deleteopt(struct vfsoptlist *opts, const char *name) 200 { 201 struct vfsopt *opt, *temp; 202 203 TAILQ_FOREACH_SAFE(opt, opts, link, temp) { 204 if (strcmp(opt->name, name) == 0) 205 vfs_freeopt(opts, opt); 206 } 207 } 208 209 /* 210 * Check if options are equal (with or without the "no" prefix). 211 */ 212 static int 213 vfs_equalopts(const char *opt1, const char *opt2) 214 { 215 216 /* "opt" vs. "opt" or "noopt" vs. "noopt" */ 217 if (strcmp(opt1, opt2) == 0) 218 return (1); 219 /* "noopt" vs. "opt" */ 220 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0) 221 return (1); 222 /* "opt" vs. "noopt" */ 223 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0) 224 return (1); 225 return (0); 226 } 227 228 /* 229 * If a mount option is specified several times, 230 * (with or without the "no" prefix) only keep 231 * the last occurence of it. 232 */ 233 static void 234 vfs_sanitizeopts(struct vfsoptlist *opts) 235 { 236 struct vfsopt *opt, *opt2, *tmp; 237 238 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) { 239 opt2 = TAILQ_PREV(opt, vfsoptlist, link); 240 while (opt2 != NULL) { 241 if (vfs_equalopts(opt->name, opt2->name)) { 242 tmp = TAILQ_PREV(opt2, vfsoptlist, link); 243 vfs_freeopt(opts, opt2); 244 opt2 = tmp; 245 } else { 246 opt2 = TAILQ_PREV(opt2, vfsoptlist, link); 247 } 248 } 249 } 250 } 251 252 /* 253 * Build a linked list of mount options from a struct uio. 254 */ 255 static int 256 vfs_buildopts(struct uio *auio, struct vfsoptlist **options) 257 { 258 struct vfsoptlist *opts; 259 struct vfsopt *opt; 260 size_t memused; 261 unsigned int i, iovcnt; 262 int error, namelen, optlen; 263 264 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 265 TAILQ_INIT(opts); 266 memused = 0; 267 iovcnt = auio->uio_iovcnt; 268 for (i = 0; i < iovcnt; i += 2) { 269 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 270 namelen = auio->uio_iov[i].iov_len; 271 optlen = auio->uio_iov[i + 1].iov_len; 272 opt->name = malloc(namelen, M_MOUNT, M_WAITOK); 273 opt->value = NULL; 274 opt->len = 0; 275 276 /* 277 * Do this early, so jumps to "bad" will free the current 278 * option. 279 */ 280 TAILQ_INSERT_TAIL(opts, opt, link); 281 memused += sizeof(struct vfsopt) + optlen + namelen; 282 283 /* 284 * Avoid consuming too much memory, and attempts to overflow 285 * memused. 286 */ 287 if (memused > VFS_MOUNTARG_SIZE_MAX || 288 optlen > VFS_MOUNTARG_SIZE_MAX || 289 namelen > VFS_MOUNTARG_SIZE_MAX) { 290 error = EINVAL; 291 goto bad; 292 } 293 294 if (auio->uio_segflg == UIO_SYSSPACE) { 295 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen); 296 } else { 297 error = copyin(auio->uio_iov[i].iov_base, opt->name, 298 namelen); 299 if (error) 300 goto bad; 301 } 302 /* Ensure names are null-terminated strings. */ 303 if (opt->name[namelen - 1] != '\0') { 304 error = EINVAL; 305 goto bad; 306 } 307 if (optlen != 0) { 308 opt->len = optlen; 309 opt->value = malloc(optlen, M_MOUNT, M_WAITOK); 310 if (auio->uio_segflg == UIO_SYSSPACE) { 311 bcopy(auio->uio_iov[i + 1].iov_base, opt->value, 312 optlen); 313 } else { 314 error = copyin(auio->uio_iov[i + 1].iov_base, 315 opt->value, optlen); 316 if (error) 317 goto bad; 318 } 319 } 320 } 321 vfs_sanitizeopts(opts); 322 *options = opts; 323 return (0); 324 bad: 325 vfs_freeopts(opts); 326 return (error); 327 } 328 329 /* 330 * Merge the old mount options with the new ones passed 331 * in the MNT_UPDATE case. 332 */ 333 static void 334 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts) 335 { 336 struct vfsopt *opt, *opt2, *new; 337 338 TAILQ_FOREACH(opt, opts, link) { 339 /* 340 * Check that this option hasn't been redefined 341 * nor cancelled with a "no" mount option. 342 */ 343 opt2 = TAILQ_FIRST(toopts); 344 while (opt2 != NULL) { 345 if (strcmp(opt2->name, opt->name) == 0) 346 goto next; 347 if (strncmp(opt2->name, "no", 2) == 0 && 348 strcmp(opt2->name + 2, opt->name) == 0) { 349 vfs_freeopt(toopts, opt2); 350 goto next; 351 } 352 opt2 = TAILQ_NEXT(opt2, link); 353 } 354 /* We want this option, duplicate it. */ 355 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 356 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK); 357 strcpy(new->name, opt->name); 358 if (opt->len != 0) { 359 new->value = malloc(opt->len, M_MOUNT, M_WAITOK); 360 bcopy(opt->value, new->value, opt->len); 361 } else { 362 new->value = NULL; 363 } 364 new->len = opt->len; 365 TAILQ_INSERT_TAIL(toopts, new, link); 366 next: 367 continue; 368 } 369 } 370 371 /* 372 * --------------------------------------------------------------------- 373 * Mount a filesystem 374 */ 375 int 376 nmount(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 free(auio, M_IOV); 417 return (error); 418 } 419 420 /* 421 * --------------------------------------------------------------------- 422 * Various utility functions 423 */ 424 425 void 426 vfs_ref(struct mount *mp) 427 { 428 429 MNT_ILOCK(mp); 430 MNT_REF(mp); 431 MNT_IUNLOCK(mp); 432 } 433 434 void 435 vfs_rel(struct mount *mp) 436 { 437 438 MNT_ILOCK(mp); 439 MNT_REL(mp); 440 MNT_IUNLOCK(mp); 441 } 442 443 static int 444 mount_init(void *mem, int size, int flags) 445 { 446 struct mount *mp; 447 448 mp = (struct mount *)mem; 449 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF); 450 lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0); 451 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0); 452 return (0); 453 } 454 455 static void 456 mount_fini(void *mem, int size) 457 { 458 struct mount *mp; 459 460 mp = (struct mount *)mem; 461 lockdestroy(&mp->mnt_explock); 462 lockdestroy(&mp->mnt_lock); 463 mtx_destroy(&mp->mnt_mtx); 464 } 465 466 /* 467 * Allocate and initialize the mount point struct. 468 */ 469 static int 470 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, 471 const char *fspath, struct thread *td, struct mount **mpp) 472 { 473 struct mount *mp; 474 475 mp = uma_zalloc(mount_zone, M_WAITOK); 476 bzero(&mp->mnt_startzero, 477 __rangeof(struct mount, mnt_startzero, mnt_endzero)); 478 bzero(&mp->mnt_startzero2, 479 __rangeof(struct mount, mnt_startzero2, mnt_endzero2)); 480 TAILQ_INIT(&mp->mnt_nvnodelist); 481 mp->mnt_nvnodelistsize = 0; 482 mp->mnt_ref = 0; 483 (void) vfs_busy(mp, LK_NOWAIT, 0, td); 484 mp->mnt_op = vfsp->vfc_vfsops; 485 mp->mnt_vfc = vfsp; 486 vfsp->vfc_refcount++; /* XXX Unlocked */ 487 mp->mnt_stat.f_type = vfsp->vfc_typenum; 488 MNT_ILOCK(mp); 489 mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK; 490 MNT_IUNLOCK(mp); 491 mp->mnt_gen++; 492 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN); 493 mp->mnt_vnodecovered = vp; 494 mp->mnt_cred = crdup(td->td_ucred); 495 mp->mnt_stat.f_owner = td->td_ucred->cr_uid; 496 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN); 497 mp->mnt_iosize_max = DFLTPHYS; 498 #ifdef MAC 499 mac_init_mount(mp); 500 mac_create_mount(td->td_ucred, mp); 501 #endif 502 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0); 503 *mpp = mp; 504 return (0); 505 } 506 507 /* 508 * Destroy the mount struct previously allocated by vfs_mount_alloc(). 509 */ 510 static void 511 vfs_mount_destroy(struct mount *mp) 512 { 513 int i; 514 515 MNT_ILOCK(mp); 516 for (i = 0; mp->mnt_ref && i < 3; i++) 517 msleep(mp, MNT_MTX(mp), PVFS, "mntref", hz); 518 /* 519 * This will always cause a 3 second delay in rebooting due to 520 * refs on the root mountpoint that never go away. Most of these 521 * are held by init which never exits. 522 */ 523 if (i == 3 && (!rebooting || bootverbose)) 524 printf("Mount point %s had %d dangling refs\n", 525 mp->mnt_stat.f_mntonname, mp->mnt_ref); 526 if (mp->mnt_holdcnt != 0) { 527 printf("Waiting for mount point to be unheld\n"); 528 while (mp->mnt_holdcnt != 0) { 529 mp->mnt_holdcntwaiters++; 530 msleep(&mp->mnt_holdcnt, MNT_MTX(mp), 531 PZERO, "mntdestroy", 0); 532 mp->mnt_holdcntwaiters--; 533 } 534 printf("mount point unheld\n"); 535 } 536 if (mp->mnt_writeopcount > 0) { 537 printf("Waiting for mount point write ops\n"); 538 while (mp->mnt_writeopcount > 0) { 539 mp->mnt_kern_flag |= MNTK_SUSPEND; 540 msleep(&mp->mnt_writeopcount, 541 MNT_MTX(mp), 542 PZERO, "mntdestroy2", 0); 543 } 544 printf("mount point write ops completed\n"); 545 } 546 if (mp->mnt_secondary_writes > 0) { 547 printf("Waiting for mount point secondary write ops\n"); 548 while (mp->mnt_secondary_writes > 0) { 549 mp->mnt_kern_flag |= MNTK_SUSPEND; 550 msleep(&mp->mnt_secondary_writes, 551 MNT_MTX(mp), 552 PZERO, "mntdestroy3", 0); 553 } 554 printf("mount point secondary write ops completed\n"); 555 } 556 MNT_IUNLOCK(mp); 557 mp->mnt_vfc->vfc_refcount--; 558 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) { 559 struct vnode *vp; 560 561 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) 562 vprint("", vp); 563 panic("unmount: dangling vnode"); 564 } 565 MNT_ILOCK(mp); 566 if (mp->mnt_kern_flag & MNTK_MWAIT) 567 wakeup(mp); 568 if (mp->mnt_writeopcount != 0) 569 panic("vfs_mount_destroy: nonzero writeopcount"); 570 if (mp->mnt_secondary_writes != 0) 571 panic("vfs_mount_destroy: nonzero secondary_writes"); 572 if (mp->mnt_nvnodelistsize != 0) 573 panic("vfs_mount_destroy: nonzero nvnodelistsize"); 574 mp->mnt_writeopcount = -1000; 575 mp->mnt_nvnodelistsize = -1000; 576 mp->mnt_secondary_writes = -1000; 577 MNT_IUNLOCK(mp); 578 #ifdef MAC 579 mac_destroy_mount(mp); 580 #endif 581 if (mp->mnt_opt != NULL) 582 vfs_freeopts(mp->mnt_opt); 583 crfree(mp->mnt_cred); 584 uma_zfree(mount_zone, mp); 585 } 586 587 static int 588 vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions) 589 { 590 struct vfsoptlist *optlist; 591 struct vfsopt *opt, *noro_opt; 592 char *fstype, *fspath, *errmsg; 593 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos; 594 int has_rw, has_noro; 595 596 errmsg = NULL; 597 errmsg_len = 0; 598 errmsg_pos = -1; 599 has_rw = 0; 600 has_noro = 0; 601 602 error = vfs_buildopts(fsoptions, &optlist); 603 if (error) 604 return (error); 605 606 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0) 607 errmsg_pos = vfs_getopt_pos(optlist, "errmsg"); 608 609 /* 610 * We need these two options before the others, 611 * and they are mandatory for any filesystem. 612 * Ensure they are NUL terminated as well. 613 */ 614 fstypelen = 0; 615 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen); 616 if (error || fstype[fstypelen - 1] != '\0') { 617 error = EINVAL; 618 if (errmsg != NULL) 619 strncpy(errmsg, "Invalid fstype", errmsg_len); 620 goto bail; 621 } 622 fspathlen = 0; 623 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen); 624 if (error || fspath[fspathlen - 1] != '\0') { 625 error = EINVAL; 626 if (errmsg != NULL) 627 strncpy(errmsg, "Invalid fspath", errmsg_len); 628 goto bail; 629 } 630 631 /* 632 * We need to see if we have the "update" option 633 * before we call vfs_domount(), since vfs_domount() has special 634 * logic based on MNT_UPDATE. This is very important 635 * when we want to update the root filesystem. 636 */ 637 TAILQ_FOREACH(opt, optlist, link) { 638 if (strcmp(opt->name, "update") == 0) 639 fsflags |= MNT_UPDATE; 640 else if (strcmp(opt->name, "async") == 0) 641 fsflags |= MNT_ASYNC; 642 else if (strcmp(opt->name, "force") == 0) 643 fsflags |= MNT_FORCE; 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, "noclusterr") == 0) 651 fsflags |= MNT_NOCLUSTERR; 652 else if (strcmp(opt->name, "noclusterw") == 0) 653 fsflags |= MNT_NOCLUSTERW; 654 else if (strcmp(opt->name, "noexec") == 0) 655 fsflags |= MNT_NOEXEC; 656 else if (strcmp(opt->name, "nosuid") == 0) 657 fsflags |= MNT_NOSUID; 658 else if (strcmp(opt->name, "nosymfollow") == 0) 659 fsflags |= MNT_NOSYMFOLLOW; 660 else if (strcmp(opt->name, "noro") == 0) { 661 fsflags &= ~MNT_RDONLY; 662 has_noro = 1; 663 } 664 else if (strcmp(opt->name, "rw") == 0) { 665 fsflags &= ~MNT_RDONLY; 666 has_rw = 1; 667 } 668 else if (strcmp(opt->name, "ro") == 0 || 669 strcmp(opt->name, "rdonly") == 0) 670 fsflags |= MNT_RDONLY; 671 else if (strcmp(opt->name, "snapshot") == 0) 672 fsflags |= MNT_SNAPSHOT; 673 else if (strcmp(opt->name, "suiddir") == 0) 674 fsflags |= MNT_SUIDDIR; 675 else if (strcmp(opt->name, "sync") == 0) 676 fsflags |= MNT_SYNCHRONOUS; 677 else if (strcmp(opt->name, "union") == 0) 678 fsflags |= MNT_UNION; 679 } 680 681 /* 682 * If "rw" was specified as a mount option, and we 683 * are trying to update a mount-point from "ro" to "rw", 684 * we need a mount option "noro", since in vfs_mergeopts(), 685 * "noro" will cancel "ro", but "rw" will not do anything. 686 */ 687 if (has_rw && !has_noro) { 688 noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK); 689 noro_opt->name = strdup("noro", M_MOUNT); 690 noro_opt->value = NULL; 691 noro_opt->len = 0; 692 TAILQ_INSERT_TAIL(optlist, noro_opt, link); 693 } 694 695 /* 696 * Be ultra-paranoid about making sure the type and fspath 697 * variables will fit in our mp buffers, including the 698 * terminating NUL. 699 */ 700 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) { 701 error = ENAMETOOLONG; 702 goto bail; 703 } 704 705 mtx_lock(&Giant); 706 error = vfs_domount(td, fstype, fspath, fsflags, optlist); 707 mtx_unlock(&Giant); 708 bail: 709 /* copyout the errmsg */ 710 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt) 711 && errmsg_len > 0 && errmsg != NULL) { 712 if (fsoptions->uio_segflg == UIO_SYSSPACE) { 713 bcopy(errmsg, 714 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 715 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 716 } else { 717 copyout(errmsg, 718 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base, 719 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len); 720 } 721 } 722 723 if (error != 0) 724 vfs_freeopts(optlist); 725 return (error); 726 } 727 728 /* 729 * --------------------------------------------------------------------- 730 * Old mount API. 731 */ 732 #ifndef _SYS_SYSPROTO_H_ 733 struct mount_args { 734 char *type; 735 char *path; 736 int flags; 737 caddr_t data; 738 }; 739 #endif 740 /* ARGSUSED */ 741 int 742 mount(td, uap) 743 struct thread *td; 744 struct mount_args /* { 745 char *type; 746 char *path; 747 int flags; 748 caddr_t data; 749 } */ *uap; 750 { 751 char *fstype; 752 struct vfsconf *vfsp = NULL; 753 struct mntarg *ma = NULL; 754 int error; 755 756 AUDIT_ARG(fflags, uap->flags); 757 758 /* Kick out MNT_ROOTFS early as it is legal internally */ 759 uap->flags &= ~MNT_ROOTFS; 760 761 if (uap->data == NULL) 762 return (EINVAL); 763 764 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK); 765 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL); 766 if (!error) { 767 AUDIT_ARG(text, fstype); 768 mtx_lock(&Giant); /* XXX ? */ 769 vfsp = vfs_byname_kld(fstype, td, &error); 770 mtx_unlock(&Giant); 771 } 772 free(fstype, M_TEMP); 773 if (error) 774 return (error); 775 if (vfsp == NULL) 776 return (ENOENT); 777 if (vfsp->vfc_vfsops->vfs_cmount == NULL) 778 return (EOPNOTSUPP); 779 780 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN); 781 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN); 782 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro"); 783 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid"); 784 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec"); 785 786 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags, td); 787 return (error); 788 } 789 790 791 /* 792 * vfs_domount(): actually attempt a filesystem mount. 793 */ 794 static int 795 vfs_domount( 796 struct thread *td, /* Flags common to all filesystems. */ 797 const char *fstype, /* Filesystem type. */ 798 char *fspath, /* Mount path. */ 799 int fsflags, /* Flags common to all filesystems. */ 800 void *fsdata /* Options local to the filesystem. */ 801 ) 802 { 803 struct vnode *vp; 804 struct mount *mp; 805 struct vfsconf *vfsp; 806 struct export_args export; 807 int error, flag = 0; 808 struct vattr va; 809 struct nameidata nd; 810 811 mtx_assert(&Giant, MA_OWNED); 812 /* 813 * Be ultra-paranoid about making sure the type and fspath 814 * variables will fit in our mp buffers, including the 815 * terminating NUL. 816 */ 817 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN) 818 return (ENAMETOOLONG); 819 820 if (jailed(td->td_ucred)) 821 return (EPERM); 822 if (usermount == 0) { 823 if ((error = suser(td)) != 0) 824 return (error); 825 } 826 827 /* 828 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users. 829 */ 830 if (fsflags & (MNT_EXPORTED | MNT_SUIDDIR)) { 831 if ((error = suser(td)) != 0) 832 return (error); 833 } 834 /* 835 * Silently enforce MNT_NOSUID and MNT_USER for 836 * unprivileged users. 837 */ 838 if (suser(td) != 0) 839 fsflags |= MNT_NOSUID | MNT_USER; 840 841 /* Load KLDs before we lock the covered vnode to avoid reversals. */ 842 vfsp = NULL; 843 if ((fsflags & MNT_UPDATE) == 0) { 844 /* Don't try to load KLDs if we're mounting the root. */ 845 if (fsflags & MNT_ROOTFS) 846 vfsp = vfs_byname(fstype); 847 else 848 vfsp = vfs_byname_kld(fstype, td, &error); 849 if (vfsp == NULL) 850 return (ENODEV); 851 } 852 /* 853 * Get vnode to be covered 854 */ 855 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE, 856 fspath, td); 857 if ((error = namei(&nd)) != 0) 858 return (error); 859 NDFREE(&nd, NDF_ONLY_PNBUF); 860 vp = nd.ni_vp; 861 if (fsflags & MNT_UPDATE) { 862 if ((vp->v_vflag & VV_ROOT) == 0) { 863 vput(vp); 864 return (EINVAL); 865 } 866 mp = vp->v_mount; 867 MNT_ILOCK(mp); 868 flag = mp->mnt_flag; 869 /* 870 * We only allow the filesystem to be reloaded if it 871 * is currently mounted read-only. 872 */ 873 if ((fsflags & MNT_RELOAD) && 874 ((mp->mnt_flag & MNT_RDONLY) == 0)) { 875 MNT_IUNLOCK(mp); 876 vput(vp); 877 return (EOPNOTSUPP); /* Needs translation */ 878 } 879 MNT_IUNLOCK(mp); 880 /* 881 * Only privileged root, or (if MNT_USER is set) the user that 882 * did the original mount is permitted to update it. 883 */ 884 error = vfs_suser(mp, td); 885 if (error) { 886 vput(vp); 887 return (error); 888 } 889 if (vfs_busy(mp, LK_NOWAIT, 0, td)) { 890 vput(vp); 891 return (EBUSY); 892 } 893 VI_LOCK(vp); 894 if ((vp->v_iflag & VI_MOUNT) != 0 || 895 vp->v_mountedhere != NULL) { 896 VI_UNLOCK(vp); 897 vfs_unbusy(mp, td); 898 vput(vp); 899 return (EBUSY); 900 } 901 vp->v_iflag |= VI_MOUNT; 902 VI_UNLOCK(vp); 903 MNT_ILOCK(mp); 904 mp->mnt_flag |= fsflags & 905 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS); 906 MNT_IUNLOCK(mp); 907 VOP_UNLOCK(vp, 0, td); 908 mp->mnt_optnew = fsdata; 909 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt); 910 } else { 911 /* 912 * If the user is not root, ensure that they own the directory 913 * onto which we are attempting to mount. 914 */ 915 error = VOP_GETATTR(vp, &va, td->td_ucred, td); 916 if (error) { 917 vput(vp); 918 return (error); 919 } 920 if (va.va_uid != td->td_ucred->cr_uid) { 921 if ((error = suser(td)) != 0) { 922 vput(vp); 923 return (error); 924 } 925 } 926 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 927 if (error != 0) { 928 vput(vp); 929 return (error); 930 } 931 if (vp->v_type != VDIR) { 932 vput(vp); 933 return (ENOTDIR); 934 } 935 VI_LOCK(vp); 936 if ((vp->v_iflag & VI_MOUNT) != 0 || 937 vp->v_mountedhere != NULL) { 938 VI_UNLOCK(vp); 939 vput(vp); 940 return (EBUSY); 941 } 942 vp->v_iflag |= VI_MOUNT; 943 VI_UNLOCK(vp); 944 945 /* 946 * Allocate and initialize the filesystem. 947 */ 948 error = vfs_mount_alloc(vp, vfsp, fspath, td, &mp); 949 if (error) { 950 vput(vp); 951 return (error); 952 } 953 VOP_UNLOCK(vp, 0, td); 954 955 /* XXXMAC: pass to vfs_mount_alloc? */ 956 mp->mnt_optnew = fsdata; 957 } 958 959 /* 960 * Set the mount level flags. 961 */ 962 MNT_ILOCK(mp); 963 mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) | 964 (fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS | 965 MNT_RDONLY)); 966 MNT_IUNLOCK(mp); 967 /* 968 * Mount the filesystem. 969 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they 970 * get. No freeing of cn_pnbuf. 971 */ 972 error = VFS_MOUNT(mp, td); 973 974 /* 975 * Process the export option only if we are 976 * updating mount options. 977 */ 978 if (!error && (fsflags & MNT_UPDATE)) { 979 if (vfs_copyopt(mp->mnt_optnew, "export", &export, 980 sizeof(export)) == 0) 981 error = vfs_export(mp, &export); 982 } 983 984 if (!error) { 985 if (mp->mnt_opt != NULL) 986 vfs_freeopts(mp->mnt_opt); 987 mp->mnt_opt = mp->mnt_optnew; 988 (void)VFS_STATFS(mp, &mp->mnt_stat, td); 989 } 990 /* 991 * Prevent external consumers of mount options from reading 992 * mnt_optnew. 993 */ 994 mp->mnt_optnew = NULL; 995 if (mp->mnt_flag & MNT_UPDATE) { 996 MNT_ILOCK(mp); 997 if (error) 998 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) | 999 (flag & ~MNT_QUOTA); 1000 else 1001 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD | 1002 MNT_FORCE | MNT_SNAPSHOT); 1003 MNT_IUNLOCK(mp); 1004 if ((mp->mnt_flag & MNT_RDONLY) == 0) { 1005 if (mp->mnt_syncer == NULL) 1006 error = vfs_allocate_syncvnode(mp); 1007 } else { 1008 if (mp->mnt_syncer != NULL) 1009 vrele(mp->mnt_syncer); 1010 mp->mnt_syncer = NULL; 1011 } 1012 vfs_unbusy(mp, td); 1013 VI_LOCK(vp); 1014 vp->v_iflag &= ~VI_MOUNT; 1015 VI_UNLOCK(vp); 1016 vrele(vp); 1017 return (error); 1018 } 1019 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1020 /* 1021 * Put the new filesystem on the mount list after root. 1022 */ 1023 cache_purge(vp); 1024 if (!error) { 1025 struct vnode *newdp; 1026 1027 VI_LOCK(vp); 1028 vp->v_iflag &= ~VI_MOUNT; 1029 VI_UNLOCK(vp); 1030 vp->v_mountedhere = mp; 1031 mtx_lock(&mountlist_mtx); 1032 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1033 mtx_unlock(&mountlist_mtx); 1034 vfs_event_signal(NULL, VQ_MOUNT, 0); 1035 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp, td)) 1036 panic("mount: lost mount"); 1037 mountcheckdirs(vp, newdp); 1038 vput(newdp); 1039 VOP_UNLOCK(vp, 0, td); 1040 if ((mp->mnt_flag & MNT_RDONLY) == 0) 1041 error = vfs_allocate_syncvnode(mp); 1042 vfs_unbusy(mp, td); 1043 if (error) 1044 vrele(vp); 1045 } else { 1046 VI_LOCK(vp); 1047 vp->v_iflag &= ~VI_MOUNT; 1048 VI_UNLOCK(vp); 1049 vfs_unbusy(mp, td); 1050 vfs_mount_destroy(mp); 1051 vput(vp); 1052 } 1053 return (error); 1054 } 1055 1056 /* 1057 * --------------------------------------------------------------------- 1058 * Unmount a filesystem. 1059 * 1060 * Note: unmount takes a path to the vnode mounted on as argument, 1061 * not special file (as before). 1062 */ 1063 #ifndef _SYS_SYSPROTO_H_ 1064 struct unmount_args { 1065 char *path; 1066 int flags; 1067 }; 1068 #endif 1069 /* ARGSUSED */ 1070 int 1071 unmount(td, uap) 1072 struct thread *td; 1073 register struct unmount_args /* { 1074 char *path; 1075 int flags; 1076 } */ *uap; 1077 { 1078 struct mount *mp; 1079 char *pathbuf; 1080 int error, id0, id1; 1081 1082 if (jailed(td->td_ucred)) 1083 return (EPERM); 1084 if (usermount == 0) { 1085 if ((error = suser(td)) != 0) 1086 return (error); 1087 } 1088 1089 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK); 1090 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL); 1091 if (error) { 1092 free(pathbuf, M_TEMP); 1093 return (error); 1094 } 1095 AUDIT_ARG(upath, td, pathbuf, ARG_UPATH1); 1096 if (uap->flags & MNT_BYFSID) { 1097 /* Decode the filesystem ID. */ 1098 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) { 1099 free(pathbuf, M_TEMP); 1100 return (EINVAL); 1101 } 1102 1103 mtx_lock(&mountlist_mtx); 1104 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1105 if (mp->mnt_stat.f_fsid.val[0] == id0 && 1106 mp->mnt_stat.f_fsid.val[1] == id1) 1107 break; 1108 } 1109 mtx_unlock(&mountlist_mtx); 1110 } else { 1111 mtx_lock(&mountlist_mtx); 1112 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) { 1113 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0) 1114 break; 1115 } 1116 mtx_unlock(&mountlist_mtx); 1117 } 1118 free(pathbuf, M_TEMP); 1119 if (mp == NULL) { 1120 /* 1121 * Previously we returned ENOENT for a nonexistent path and 1122 * EINVAL for a non-mountpoint. We cannot tell these apart 1123 * now, so in the !MNT_BYFSID case return the more likely 1124 * EINVAL for compatibility. 1125 */ 1126 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL); 1127 } 1128 1129 /* 1130 * Don't allow unmounting the root filesystem. 1131 */ 1132 if (mp->mnt_flag & MNT_ROOTFS) 1133 return (EINVAL); 1134 mtx_lock(&Giant); 1135 error = dounmount(mp, uap->flags, td); 1136 mtx_unlock(&Giant); 1137 return (error); 1138 } 1139 1140 /* 1141 * Do the actual filesystem unmount. 1142 */ 1143 int 1144 dounmount(mp, flags, td) 1145 struct mount *mp; 1146 int flags; 1147 struct thread *td; 1148 { 1149 struct vnode *coveredvp, *fsrootvp; 1150 int error; 1151 int async_flag; 1152 int mnt_gen_r; 1153 1154 mtx_assert(&Giant, MA_OWNED); 1155 1156 if ((coveredvp = mp->mnt_vnodecovered) != NULL) { 1157 mnt_gen_r = mp->mnt_gen; 1158 VI_LOCK(coveredvp); 1159 vholdl(coveredvp); 1160 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY, td); 1161 vdrop(coveredvp); 1162 /* 1163 * Check for mp being unmounted while waiting for the 1164 * covered vnode lock. 1165 */ 1166 if (coveredvp->v_mountedhere != mp || 1167 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) { 1168 VOP_UNLOCK(coveredvp, 0, td); 1169 return (EBUSY); 1170 } 1171 } 1172 /* 1173 * Only privileged root, or (if MNT_USER is set) the user that did the 1174 * original mount is permitted to unmount this filesystem. 1175 */ 1176 error = vfs_suser(mp, td); 1177 if (error) { 1178 if (coveredvp) 1179 VOP_UNLOCK(coveredvp, 0, td); 1180 return (error); 1181 } 1182 1183 MNT_ILOCK(mp); 1184 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 1185 MNT_IUNLOCK(mp); 1186 if (coveredvp) 1187 VOP_UNLOCK(coveredvp, 0, td); 1188 return (EBUSY); 1189 } 1190 mp->mnt_kern_flag |= MNTK_UNMOUNT; 1191 /* Allow filesystems to detect that a forced unmount is in progress. */ 1192 if (flags & MNT_FORCE) 1193 mp->mnt_kern_flag |= MNTK_UNMOUNTF; 1194 error = lockmgr(&mp->mnt_lock, LK_DRAIN | LK_INTERLOCK | 1195 ((flags & MNT_FORCE) ? 0 : LK_NOWAIT), MNT_MTX(mp), td); 1196 if (error) { 1197 MNT_ILOCK(mp); 1198 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1199 if (mp->mnt_kern_flag & MNTK_MWAIT) 1200 wakeup(mp); 1201 MNT_IUNLOCK(mp); 1202 if (coveredvp) 1203 VOP_UNLOCK(coveredvp, 0, td); 1204 return (error); 1205 } 1206 vn_start_write(NULL, &mp, V_WAIT); 1207 1208 if (mp->mnt_flag & MNT_EXPUBLIC) 1209 vfs_setpublicfs(NULL, NULL, NULL); 1210 1211 vfs_msync(mp, MNT_WAIT); 1212 MNT_ILOCK(mp); 1213 async_flag = mp->mnt_flag & MNT_ASYNC; 1214 mp->mnt_flag &= ~MNT_ASYNC; 1215 MNT_IUNLOCK(mp); 1216 cache_purgevfs(mp); /* remove cache entries for this file sys */ 1217 if (mp->mnt_syncer != NULL) 1218 vrele(mp->mnt_syncer); 1219 /* 1220 * For forced unmounts, move process cdir/rdir refs on the fs root 1221 * vnode to the covered vnode. For non-forced unmounts we want 1222 * such references to cause an EBUSY error. 1223 */ 1224 if ((flags & MNT_FORCE) && 1225 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1226 if (mp->mnt_vnodecovered != NULL) 1227 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered); 1228 if (fsrootvp == rootvnode) { 1229 vrele(rootvnode); 1230 rootvnode = NULL; 1231 } 1232 vput(fsrootvp); 1233 } 1234 if (((mp->mnt_flag & MNT_RDONLY) || 1235 (error = VFS_SYNC(mp, MNT_WAIT, td)) == 0) || 1236 (flags & MNT_FORCE)) { 1237 error = VFS_UNMOUNT(mp, flags, td); 1238 } 1239 vn_finished_write(mp); 1240 if (error) { 1241 /* Undo cdir/rdir and rootvnode changes made above. */ 1242 if ((flags & MNT_FORCE) && 1243 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp, td) == 0) { 1244 if (mp->mnt_vnodecovered != NULL) 1245 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp); 1246 if (rootvnode == NULL) { 1247 rootvnode = fsrootvp; 1248 vref(rootvnode); 1249 } 1250 vput(fsrootvp); 1251 } 1252 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) 1253 (void) vfs_allocate_syncvnode(mp); 1254 MNT_ILOCK(mp); 1255 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF); 1256 mp->mnt_flag |= async_flag; 1257 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1258 if (mp->mnt_kern_flag & MNTK_MWAIT) 1259 wakeup(mp); 1260 MNT_IUNLOCK(mp); 1261 if (coveredvp) 1262 VOP_UNLOCK(coveredvp, 0, td); 1263 return (error); 1264 } 1265 mtx_lock(&mountlist_mtx); 1266 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1267 mtx_unlock(&mountlist_mtx); 1268 if (coveredvp != NULL) { 1269 coveredvp->v_mountedhere = NULL; 1270 vput(coveredvp); 1271 } 1272 vfs_event_signal(NULL, VQ_UNMOUNT, 0); 1273 lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td); 1274 vfs_mount_destroy(mp); 1275 return (0); 1276 } 1277 1278 /* 1279 * --------------------------------------------------------------------- 1280 * Mounting of root filesystem 1281 * 1282 */ 1283 1284 struct root_hold_token { 1285 const char *who; 1286 LIST_ENTRY(root_hold_token) list; 1287 }; 1288 1289 static LIST_HEAD(, root_hold_token) root_holds = 1290 LIST_HEAD_INITIALIZER(&root_holds); 1291 1292 struct root_hold_token * 1293 root_mount_hold(const char *identifier) 1294 { 1295 struct root_hold_token *h; 1296 1297 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK); 1298 h->who = identifier; 1299 mtx_lock(&mountlist_mtx); 1300 LIST_INSERT_HEAD(&root_holds, h, list); 1301 mtx_unlock(&mountlist_mtx); 1302 return (h); 1303 } 1304 1305 void 1306 root_mount_rel(struct root_hold_token *h) 1307 { 1308 1309 mtx_lock(&mountlist_mtx); 1310 LIST_REMOVE(h, list); 1311 wakeup(&root_holds); 1312 mtx_unlock(&mountlist_mtx); 1313 free(h, M_DEVBUF); 1314 } 1315 1316 static void 1317 root_mount_wait(void) 1318 { 1319 struct root_hold_token *h; 1320 1321 for (;;) { 1322 DROP_GIANT(); 1323 g_waitidle(); 1324 PICKUP_GIANT(); 1325 mtx_lock(&mountlist_mtx); 1326 if (LIST_EMPTY(&root_holds)) { 1327 mtx_unlock(&mountlist_mtx); 1328 break; 1329 } 1330 printf("Root mount waiting for:"); 1331 LIST_FOREACH(h, &root_holds, list) 1332 printf(" %s", h->who); 1333 printf("\n"); 1334 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold", 1335 hz); 1336 } 1337 } 1338 1339 static void 1340 set_rootvnode(struct thread *td) 1341 { 1342 struct proc *p; 1343 1344 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode, td)) 1345 panic("Cannot find root vnode"); 1346 1347 p = td->td_proc; 1348 FILEDESC_LOCK(p->p_fd); 1349 1350 if (p->p_fd->fd_cdir != NULL) 1351 vrele(p->p_fd->fd_cdir); 1352 p->p_fd->fd_cdir = rootvnode; 1353 VREF(rootvnode); 1354 1355 if (p->p_fd->fd_rdir != NULL) 1356 vrele(p->p_fd->fd_rdir); 1357 p->p_fd->fd_rdir = rootvnode; 1358 VREF(rootvnode); 1359 1360 FILEDESC_UNLOCK(p->p_fd); 1361 1362 VOP_UNLOCK(rootvnode, 0, td); 1363 1364 EVENTHANDLER_INVOKE(mountroot); 1365 } 1366 1367 /* 1368 * Mount /devfs as our root filesystem, but do not put it on the mountlist 1369 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup. 1370 */ 1371 1372 static void 1373 devfs_first(void) 1374 { 1375 struct thread *td = curthread; 1376 struct vfsoptlist *opts; 1377 struct vfsconf *vfsp; 1378 struct mount *mp = NULL; 1379 int error; 1380 1381 vfsp = vfs_byname("devfs"); 1382 KASSERT(vfsp != NULL, ("Could not find devfs by name")); 1383 if (vfsp == NULL) 1384 return; 1385 1386 error = vfs_mount_alloc(NULLVP, vfsp, "/dev", td, &mp); 1387 KASSERT(error == 0, ("vfs_mount_alloc failed %d", error)); 1388 if (error) 1389 return; 1390 1391 error = VFS_MOUNT(mp, curthread); 1392 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error)); 1393 if (error) 1394 return; 1395 1396 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK); 1397 TAILQ_INIT(opts); 1398 mp->mnt_opt = opts; 1399 1400 mtx_lock(&mountlist_mtx); 1401 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 1402 mtx_unlock(&mountlist_mtx); 1403 1404 set_rootvnode(td); 1405 1406 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE); 1407 if (error) 1408 printf("kern_symlink /dev -> / returns %d\n", error); 1409 } 1410 1411 /* 1412 * Surgically move our devfs to be mounted on /dev. 1413 */ 1414 1415 static void 1416 devfs_fixup(struct thread *td) 1417 { 1418 struct nameidata nd; 1419 int error; 1420 struct vnode *vp, *dvp; 1421 struct mount *mp; 1422 1423 /* Remove our devfs mount from the mountlist and purge the cache */ 1424 mtx_lock(&mountlist_mtx); 1425 mp = TAILQ_FIRST(&mountlist); 1426 TAILQ_REMOVE(&mountlist, mp, mnt_list); 1427 mtx_unlock(&mountlist_mtx); 1428 cache_purgevfs(mp); 1429 1430 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp, td); 1431 VI_LOCK(dvp); 1432 dvp->v_iflag &= ~VI_MOUNT; 1433 dvp->v_mountedhere = NULL; 1434 VI_UNLOCK(dvp); 1435 1436 /* Set up the real rootvnode, and purge the cache */ 1437 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL; 1438 set_rootvnode(td); 1439 cache_purgevfs(rootvnode->v_mount); 1440 1441 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td); 1442 error = namei(&nd); 1443 if (error) { 1444 printf("Lookup of /dev for devfs, error: %d\n", error); 1445 return; 1446 } 1447 NDFREE(&nd, NDF_ONLY_PNBUF); 1448 vp = nd.ni_vp; 1449 if (vp->v_type != VDIR) { 1450 vput(vp); 1451 } 1452 error = vinvalbuf(vp, V_SAVE, td, 0, 0); 1453 if (error) { 1454 vput(vp); 1455 } 1456 cache_purge(vp); 1457 mp->mnt_vnodecovered = vp; 1458 vp->v_mountedhere = mp; 1459 mtx_lock(&mountlist_mtx); 1460 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 1461 mtx_unlock(&mountlist_mtx); 1462 VOP_UNLOCK(vp, 0, td); 1463 vput(dvp); 1464 vfs_unbusy(mp, td); 1465 1466 /* Unlink the no longer needed /dev/dev -> / symlink */ 1467 kern_unlink(td, "/dev/dev", UIO_SYSSPACE); 1468 } 1469 1470 /* 1471 * Report errors during filesystem mounting. 1472 */ 1473 void 1474 vfs_mount_error(struct mount *mp, const char *fmt, ...) 1475 { 1476 struct vfsoptlist *moptlist = mp->mnt_optnew; 1477 va_list ap; 1478 int error, len; 1479 char *errmsg; 1480 1481 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len); 1482 if (error || errmsg == NULL || len <= 0) { 1483 return; 1484 } 1485 1486 va_start(ap, fmt); 1487 vsnprintf(errmsg, (size_t)len, fmt, ap); 1488 va_end(ap); 1489 } 1490 1491 /* 1492 * Find and mount the root filesystem 1493 */ 1494 void 1495 vfs_mountroot(void) 1496 { 1497 char *cp; 1498 int error, i, asked = 0; 1499 1500 root_mount_wait(); 1501 1502 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount), 1503 NULL, NULL, mount_init, mount_fini, 1504 UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1505 devfs_first(); 1506 1507 /* 1508 * We are booted with instructions to prompt for the root filesystem. 1509 */ 1510 if (boothowto & RB_ASKNAME) { 1511 if (!vfs_mountroot_ask()) 1512 return; 1513 asked = 1; 1514 } 1515 1516 /* 1517 * The root filesystem information is compiled in, and we are 1518 * booted with instructions to use it. 1519 */ 1520 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) { 1521 if (!vfs_mountroot_try(ctrootdevname)) 1522 return; 1523 ctrootdevname = NULL; 1524 } 1525 1526 /* 1527 * We've been given the generic "use CDROM as root" flag. This is 1528 * necessary because one media may be used in many different 1529 * devices, so we need to search for them. 1530 */ 1531 if (boothowto & RB_CDROM) { 1532 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 1533 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 1534 return; 1535 } 1536 } 1537 1538 /* 1539 * Try to use the value read by the loader from /etc/fstab, or 1540 * supplied via some other means. This is the preferred 1541 * mechanism. 1542 */ 1543 cp = getenv("vfs.root.mountfrom"); 1544 if (cp != NULL) { 1545 error = vfs_mountroot_try(cp); 1546 freeenv(cp); 1547 if (!error) 1548 return; 1549 } 1550 1551 /* 1552 * Try values that may have been computed by code during boot 1553 */ 1554 if (!vfs_mountroot_try(rootdevnames[0])) 1555 return; 1556 if (!vfs_mountroot_try(rootdevnames[1])) 1557 return; 1558 1559 /* 1560 * If we (still) have a compiled-in default, try it. 1561 */ 1562 if (ctrootdevname != NULL) 1563 if (!vfs_mountroot_try(ctrootdevname)) 1564 return; 1565 /* 1566 * Everything so far has failed, prompt on the console if we haven't 1567 * already tried that. 1568 */ 1569 if (!asked) 1570 if (!vfs_mountroot_ask()) 1571 return; 1572 1573 panic("Root mount failed, startup aborted."); 1574 } 1575 1576 /* 1577 * Mount (mountfrom) as the root filesystem. 1578 */ 1579 static int 1580 vfs_mountroot_try(const char *mountfrom) 1581 { 1582 struct mount *mp; 1583 char *vfsname, *path; 1584 time_t timebase; 1585 int error; 1586 char patt[32]; 1587 1588 vfsname = NULL; 1589 path = NULL; 1590 mp = NULL; 1591 error = EINVAL; 1592 1593 if (mountfrom == NULL) 1594 return (error); /* don't complain */ 1595 printf("Trying to mount root from %s\n", mountfrom); 1596 1597 /* parse vfs name and path */ 1598 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 1599 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 1600 vfsname[0] = path[0] = 0; 1601 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 1602 if (sscanf(mountfrom, patt, vfsname, path) < 1) 1603 goto out; 1604 1605 if (path[0] == '\0') 1606 strcpy(path, ROOTNAME); 1607 1608 error = kernel_vmount( 1609 MNT_RDONLY | MNT_ROOTFS, 1610 "fstype", vfsname, 1611 "fspath", "/", 1612 "from", path, 1613 NULL); 1614 if (error == 0) { 1615 /* 1616 * We mount devfs prior to mounting the / FS, so the first 1617 * entry will typically be devfs. 1618 */ 1619 mp = TAILQ_FIRST(&mountlist); 1620 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__)); 1621 1622 /* 1623 * Iterate over all currently mounted file systems and use 1624 * the time stamp found to check and/or initialize the RTC. 1625 * Typically devfs has no time stamp and the only other FS 1626 * is the actual / FS. 1627 * Call inittodr() only once and pass it the largest of the 1628 * timestamps we encounter. 1629 */ 1630 timebase = 0; 1631 do { 1632 if (mp->mnt_time > timebase) 1633 timebase = mp->mnt_time; 1634 mp = TAILQ_NEXT(mp, mnt_list); 1635 } while (mp != NULL); 1636 inittodr(timebase); 1637 1638 devfs_fixup(curthread); 1639 } 1640 out: 1641 free(path, M_MOUNT); 1642 free(vfsname, M_MOUNT); 1643 return (error); 1644 } 1645 1646 /* 1647 * --------------------------------------------------------------------- 1648 * Interactive root filesystem selection code. 1649 */ 1650 1651 static int 1652 vfs_mountroot_ask(void) 1653 { 1654 char name[128]; 1655 1656 for(;;) { 1657 printf("\nManual root filesystem specification:\n"); 1658 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 1659 #if defined(__i386__) || defined(__ia64__) 1660 printf(" eg. ufs:da0s1a\n"); 1661 #else 1662 printf(" eg. ufs:/dev/da0a\n"); 1663 #endif 1664 printf(" ? List valid disk boot devices\n"); 1665 printf(" <empty line> Abort manual input\n"); 1666 printf("\nmountroot> "); 1667 gets(name, sizeof(name), 1); 1668 if (name[0] == '\0') 1669 return (1); 1670 if (name[0] == '?') { 1671 printf("\nList of GEOM managed disk devices:\n "); 1672 g_dev_print(); 1673 continue; 1674 } 1675 if (!vfs_mountroot_try(name)) 1676 return (0); 1677 } 1678 } 1679 1680 /* 1681 * --------------------------------------------------------------------- 1682 * Functions for querying mount options/arguments from filesystems. 1683 */ 1684 1685 /* 1686 * Check that no unknown options are given 1687 */ 1688 int 1689 vfs_filteropt(struct vfsoptlist *opts, const char **legal) 1690 { 1691 struct vfsopt *opt; 1692 const char **t, *p; 1693 1694 1695 TAILQ_FOREACH(opt, opts, link) { 1696 p = opt->name; 1697 if (p[0] == 'n' && p[1] == 'o') 1698 p += 2; 1699 for(t = global_opts; *t != NULL; t++) 1700 if (!strcmp(*t, p)) 1701 break; 1702 if (*t != NULL) 1703 continue; 1704 for(t = legal; *t != NULL; t++) 1705 if (!strcmp(*t, p)) 1706 break; 1707 if (*t != NULL) 1708 continue; 1709 printf("mount option <%s> is unknown\n", p); 1710 return (EINVAL); 1711 } 1712 return (0); 1713 } 1714 1715 /* 1716 * Get a mount option by its name. 1717 * 1718 * Return 0 if the option was found, ENOENT otherwise. 1719 * If len is non-NULL it will be filled with the length 1720 * of the option. If buf is non-NULL, it will be filled 1721 * with the address of the option. 1722 */ 1723 int 1724 vfs_getopt(opts, name, buf, len) 1725 struct vfsoptlist *opts; 1726 const char *name; 1727 void **buf; 1728 int *len; 1729 { 1730 struct vfsopt *opt; 1731 1732 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1733 1734 TAILQ_FOREACH(opt, opts, link) { 1735 if (strcmp(name, opt->name) == 0) { 1736 if (len != NULL) 1737 *len = opt->len; 1738 if (buf != NULL) 1739 *buf = opt->value; 1740 return (0); 1741 } 1742 } 1743 return (ENOENT); 1744 } 1745 1746 static int 1747 vfs_getopt_pos(struct vfsoptlist *opts, const char *name) 1748 { 1749 struct vfsopt *opt; 1750 int i; 1751 1752 if (opts == NULL) 1753 return (-1); 1754 1755 i = 0; 1756 TAILQ_FOREACH(opt, opts, link) { 1757 if (strcmp(name, opt->name) == 0) 1758 return (i); 1759 ++i; 1760 } 1761 return (-1); 1762 } 1763 1764 char * 1765 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error) 1766 { 1767 struct vfsopt *opt; 1768 1769 *error = 0; 1770 TAILQ_FOREACH(opt, opts, link) { 1771 if (strcmp(name, opt->name) != 0) 1772 continue; 1773 if (((char *)opt->value)[opt->len - 1] != '\0') { 1774 *error = EINVAL; 1775 return (NULL); 1776 } 1777 return (opt->value); 1778 } 1779 return (NULL); 1780 } 1781 1782 int 1783 vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val) 1784 { 1785 struct vfsopt *opt; 1786 1787 TAILQ_FOREACH(opt, opts, link) { 1788 if (strcmp(name, opt->name) == 0) { 1789 if (w != NULL) 1790 *w |= val; 1791 return (1); 1792 } 1793 } 1794 if (w != NULL) 1795 *w &= ~val; 1796 return (0); 1797 } 1798 1799 int 1800 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...) 1801 { 1802 va_list ap; 1803 struct vfsopt *opt; 1804 int ret; 1805 1806 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL")); 1807 1808 TAILQ_FOREACH(opt, opts, link) { 1809 if (strcmp(name, opt->name) != 0) 1810 continue; 1811 if (((char *)opt->value)[opt->len - 1] != '\0') 1812 return (0); 1813 va_start(ap, fmt); 1814 ret = vsscanf(opt->value, fmt, ap); 1815 va_end(ap); 1816 return (ret); 1817 } 1818 return (0); 1819 } 1820 1821 /* 1822 * Find and copy a mount option. 1823 * 1824 * The size of the buffer has to be specified 1825 * in len, if it is not the same length as the 1826 * mount option, EINVAL is returned. 1827 * Returns ENOENT if the option is not found. 1828 */ 1829 int 1830 vfs_copyopt(opts, name, dest, len) 1831 struct vfsoptlist *opts; 1832 const char *name; 1833 void *dest; 1834 int len; 1835 { 1836 struct vfsopt *opt; 1837 1838 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL")); 1839 1840 TAILQ_FOREACH(opt, opts, link) { 1841 if (strcmp(name, opt->name) == 0) { 1842 if (len != opt->len) 1843 return (EINVAL); 1844 bcopy(opt->value, dest, opt->len); 1845 return (0); 1846 } 1847 } 1848 return (ENOENT); 1849 } 1850 1851 /* 1852 * This is a helper function for filesystems to traverse their 1853 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h 1854 */ 1855 1856 struct vnode * 1857 __mnt_vnode_next(struct vnode **mvp, struct mount *mp) 1858 { 1859 struct vnode *vp; 1860 1861 mtx_assert(MNT_MTX(mp), MA_OWNED); 1862 1863 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 1864 vp = TAILQ_NEXT(*mvp, v_nmntvnodes); 1865 while (vp != NULL && vp->v_type == VMARKER) 1866 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1867 1868 /* Check if we are done */ 1869 if (vp == NULL) { 1870 __mnt_vnode_markerfree(mvp, mp); 1871 return (NULL); 1872 } 1873 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 1874 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1875 return (vp); 1876 } 1877 1878 struct vnode * 1879 __mnt_vnode_first(struct vnode **mvp, struct mount *mp) 1880 { 1881 struct vnode *vp; 1882 1883 mtx_assert(MNT_MTX(mp), MA_OWNED); 1884 1885 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1886 while (vp != NULL && vp->v_type == VMARKER) 1887 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1888 1889 /* Check if we are done */ 1890 if (vp == NULL) { 1891 *mvp = NULL; 1892 return (NULL); 1893 } 1894 mp->mnt_holdcnt++; 1895 MNT_IUNLOCK(mp); 1896 *mvp = (struct vnode *) malloc(sizeof(struct vnode), 1897 M_VNODE_MARKER, 1898 M_WAITOK | M_ZERO); 1899 MNT_ILOCK(mp); 1900 (*mvp)->v_type = VMARKER; 1901 1902 vp = TAILQ_FIRST(&mp->mnt_nvnodelist); 1903 while (vp != NULL && vp->v_type == VMARKER) 1904 vp = TAILQ_NEXT(vp, v_nmntvnodes); 1905 1906 /* Check if we are done */ 1907 if (vp == NULL) { 1908 MNT_IUNLOCK(mp); 1909 free(*mvp, M_VNODE_MARKER); 1910 MNT_ILOCK(mp); 1911 *mvp = NULL; 1912 mp->mnt_holdcnt--; 1913 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 1914 wakeup(&mp->mnt_holdcnt); 1915 return (NULL); 1916 } 1917 mp->mnt_markercnt++; 1918 (*mvp)->v_mount = mp; 1919 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes); 1920 return (vp); 1921 } 1922 1923 1924 void 1925 __mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp) 1926 { 1927 1928 if (*mvp == NULL) 1929 return; 1930 1931 mtx_assert(MNT_MTX(mp), MA_OWNED); 1932 1933 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch")); 1934 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes); 1935 MNT_IUNLOCK(mp); 1936 free(*mvp, M_VNODE_MARKER); 1937 MNT_ILOCK(mp); 1938 *mvp = NULL; 1939 1940 mp->mnt_markercnt--; 1941 mp->mnt_holdcnt--; 1942 if (mp->mnt_holdcnt == 0 && mp->mnt_holdcntwaiters != 0) 1943 wakeup(&mp->mnt_holdcnt); 1944 } 1945 1946 1947 int 1948 __vfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td) 1949 { 1950 int error; 1951 1952 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat, td); 1953 if (sbp != &mp->mnt_stat) 1954 *sbp = mp->mnt_stat; 1955 return (error); 1956 } 1957 1958 void 1959 vfs_mountedfrom(struct mount *mp, const char *from) 1960 { 1961 1962 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname); 1963 strlcpy(mp->mnt_stat.f_mntfromname, from, 1964 sizeof mp->mnt_stat.f_mntfromname); 1965 } 1966 1967 /* 1968 * --------------------------------------------------------------------- 1969 * This is the api for building mount args and mounting filesystems from 1970 * inside the kernel. 1971 * 1972 * The API works by accumulation of individual args. First error is 1973 * latched. 1974 * 1975 * XXX: should be documented in new manpage kernel_mount(9) 1976 */ 1977 1978 /* A memory allocation which must be freed when we are done */ 1979 struct mntaarg { 1980 SLIST_ENTRY(mntaarg) next; 1981 }; 1982 1983 /* The header for the mount arguments */ 1984 struct mntarg { 1985 struct iovec *v; 1986 int len; 1987 int error; 1988 SLIST_HEAD(, mntaarg) list; 1989 }; 1990 1991 /* 1992 * Add a boolean argument. 1993 * 1994 * flag is the boolean value. 1995 * name must start with "no". 1996 */ 1997 struct mntarg * 1998 mount_argb(struct mntarg *ma, int flag, const char *name) 1999 { 2000 2001 KASSERT(name[0] == 'n' && name[1] == 'o', 2002 ("mount_argb(...,%s): name must start with 'no'", name)); 2003 2004 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0)); 2005 } 2006 2007 /* 2008 * Add an argument printf style 2009 */ 2010 struct mntarg * 2011 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...) 2012 { 2013 va_list ap; 2014 struct mntaarg *maa; 2015 struct sbuf *sb; 2016 int len; 2017 2018 if (ma == NULL) { 2019 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2020 SLIST_INIT(&ma->list); 2021 } 2022 if (ma->error) 2023 return (ma); 2024 2025 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2026 M_MOUNT, M_WAITOK); 2027 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2028 ma->v[ma->len].iov_len = strlen(name) + 1; 2029 ma->len++; 2030 2031 sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND); 2032 va_start(ap, fmt); 2033 sbuf_vprintf(sb, fmt, ap); 2034 va_end(ap); 2035 sbuf_finish(sb); 2036 len = sbuf_len(sb) + 1; 2037 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2038 SLIST_INSERT_HEAD(&ma->list, maa, next); 2039 bcopy(sbuf_data(sb), maa + 1, len); 2040 sbuf_delete(sb); 2041 2042 ma->v[ma->len].iov_base = maa + 1; 2043 ma->v[ma->len].iov_len = len; 2044 ma->len++; 2045 2046 return (ma); 2047 } 2048 2049 /* 2050 * Add an argument which is a userland string. 2051 */ 2052 struct mntarg * 2053 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len) 2054 { 2055 struct mntaarg *maa; 2056 char *tbuf; 2057 2058 if (val == NULL) 2059 return (ma); 2060 if (ma == NULL) { 2061 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2062 SLIST_INIT(&ma->list); 2063 } 2064 if (ma->error) 2065 return (ma); 2066 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO); 2067 SLIST_INSERT_HEAD(&ma->list, maa, next); 2068 tbuf = (void *)(maa + 1); 2069 ma->error = copyinstr(val, tbuf, len, NULL); 2070 return (mount_arg(ma, name, tbuf, -1)); 2071 } 2072 2073 /* 2074 * Plain argument. 2075 * 2076 * If length is -1, use printf. 2077 */ 2078 struct mntarg * 2079 mount_arg(struct mntarg *ma, const char *name, const void *val, int len) 2080 { 2081 2082 if (ma == NULL) { 2083 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO); 2084 SLIST_INIT(&ma->list); 2085 } 2086 if (ma->error) 2087 return (ma); 2088 2089 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2), 2090 M_MOUNT, M_WAITOK); 2091 ma->v[ma->len].iov_base = (void *)(uintptr_t)name; 2092 ma->v[ma->len].iov_len = strlen(name) + 1; 2093 ma->len++; 2094 2095 ma->v[ma->len].iov_base = (void *)(uintptr_t)val; 2096 if (len < 0) 2097 ma->v[ma->len].iov_len = strlen(val) + 1; 2098 else 2099 ma->v[ma->len].iov_len = len; 2100 ma->len++; 2101 return (ma); 2102 } 2103 2104 /* 2105 * Free a mntarg structure 2106 */ 2107 static void 2108 free_mntarg(struct mntarg *ma) 2109 { 2110 struct mntaarg *maa; 2111 2112 while (!SLIST_EMPTY(&ma->list)) { 2113 maa = SLIST_FIRST(&ma->list); 2114 SLIST_REMOVE_HEAD(&ma->list, next); 2115 free(maa, M_MOUNT); 2116 } 2117 free(ma->v, M_MOUNT); 2118 free(ma, M_MOUNT); 2119 } 2120 2121 /* 2122 * Mount a filesystem 2123 */ 2124 int 2125 kernel_mount(struct mntarg *ma, int flags) 2126 { 2127 struct uio auio; 2128 int error; 2129 2130 KASSERT(ma != NULL, ("kernel_mount NULL ma")); 2131 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v")); 2132 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len)); 2133 2134 auio.uio_iov = ma->v; 2135 auio.uio_iovcnt = ma->len; 2136 auio.uio_segflg = UIO_SYSSPACE; 2137 2138 error = ma->error; 2139 if (!error) 2140 error = vfs_donmount(curthread, flags, &auio); 2141 free_mntarg(ma); 2142 return (error); 2143 } 2144 2145 /* 2146 * A printflike function to mount a filesystem. 2147 */ 2148 int 2149 kernel_vmount(int flags, ...) 2150 { 2151 struct mntarg *ma = NULL; 2152 va_list ap; 2153 const char *cp; 2154 const void *vp; 2155 int error; 2156 2157 va_start(ap, flags); 2158 for (;;) { 2159 cp = va_arg(ap, const char *); 2160 if (cp == NULL) 2161 break; 2162 vp = va_arg(ap, const void *); 2163 ma = mount_arg(ma, cp, vp, -1); 2164 } 2165 va_end(ap); 2166 2167 error = kernel_mount(ma, flags); 2168 return (error); 2169 }
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