1/* $NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos Exp $ */ 2 3/*- 4 * SPDX-License-Identifier: BSD-2-Clause-NetBSD 5 * 6 * Copyright (c) 2005 The NetBSD Foundation, Inc. 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to The NetBSD Foundation 10 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 11 * 2005 program. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35/* 36 * Efficient memory file system. 37 * 38 * tmpfs is a file system that uses FreeBSD's virtual memory 39 * sub-system to store file data and metadata in an efficient way. 40 * This means that it does not follow the structure of an on-disk file 41 * system because it simply does not need to. Instead, it uses 42 * memory-specific data structures and algorithms to automatically 43 * allocate and release resources. 44 */ 45#include <sys/cdefs.h> 46__FBSDID("$FreeBSD$"); 47 48#include <sys/param.h> 49#include <sys/systm.h> 50#include <sys/dirent.h> 51#include <sys/limits.h> 52#include <sys/lock.h> 53#include <sys/mount.h> 54#include <sys/mutex.h> 55#include <sys/proc.h> 56#include <sys/jail.h> 57#include <sys/kernel.h> 58#include <sys/rwlock.h> 59#include <sys/stat.h> 60#include <sys/sx.h> 61#include <sys/sysctl.h> 62#include <sys/vnode.h> 63 64#include <vm/vm.h> 65#include <vm/vm_param.h> 66#include <vm/pmap.h> 67#include <vm/vm_extern.h> 68#include <vm/vm_map.h> 69#include <vm/vm_object.h> 70#include <vm/vm_param.h> 71 72#include <fs/tmpfs/tmpfs.h> 73 74/* 75 * Default permission for root node 76 */ 77#define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) 78 79static MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); 80MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names"); 81 82static int tmpfs_mount(struct mount *); 83static int tmpfs_unmount(struct mount *, int); 84static int tmpfs_root(struct mount *, int flags, struct vnode **); 85static int tmpfs_fhtovp(struct mount *, struct fid *, int, 86 struct vnode **); 87static int tmpfs_statfs(struct mount *, struct statfs *); 88static void tmpfs_susp_clean(struct mount *); 89 90static const char *tmpfs_opts[] = { 91 "from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export", 92 "union", "nonc", NULL 93}; 94 95static const char *tmpfs_updateopts[] = { 96 "from", "export", "size", NULL 97}; 98 99/* 100 * Handle updates of time from writes to mmaped regions. Use 101 * MNT_VNODE_FOREACH_ALL instead of MNT_VNODE_FOREACH_ACTIVE, since 102 * unmap of the tmpfs-backed vnode does not call vinactive(), due to 103 * vm object type is OBJT_SWAP. 104 * If lazy, only handle delayed update of mtime due to the writes to 105 * mapped files. 106 */ 107static void 108tmpfs_update_mtime(struct mount *mp, bool lazy) 109{ 110 struct vnode *vp, *mvp; 111 struct vm_object *obj; 112 113 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 114 if (vp->v_type != VREG) { 115 VI_UNLOCK(vp); 116 continue; 117 } 118 obj = vp->v_object; 119 KASSERT((obj->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) == 120 (OBJ_TMPFS_NODE | OBJ_TMPFS), ("non-tmpfs obj")); 121 122 /* 123 * In lazy case, do unlocked read, avoid taking vnode 124 * lock if not needed. Lost update will be handled on 125 * the next call. 126 * For non-lazy case, we must flush all pending 127 * metadata changes now. 128 */ 129 if (!lazy || (obj->flags & OBJ_TMPFS_DIRTY) != 0) { 130 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, 131 curthread) != 0) 132 continue; 133 tmpfs_check_mtime(vp); 134 if (!lazy) 135 tmpfs_update(vp); 136 vput(vp); 137 } else { 138 VI_UNLOCK(vp); 139 continue; 140 } 141 } 142} 143 144struct tmpfs_check_rw_maps_arg { 145 bool found; 146}; 147 148static bool 149tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused, 150 vm_map_entry_t entry __unused, void *arg) 151{ 152 struct tmpfs_check_rw_maps_arg *a; 153 154 a = arg; 155 a->found = true; 156 return (true); 157} 158 159/* 160 * Revoke write permissions from all mappings of regular files 161 * belonging to the specified tmpfs mount. 162 */ 163static bool 164tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map, 165 vm_map_entry_t entry, void *arg __unused) 166{ 167 168 /* 169 * XXXKIB: might be invalidate the mapping 170 * instead ? The process is not going to be 171 * happy in any case. 172 */ 173 entry->max_protection &= ~VM_PROT_WRITE; 174 if ((entry->protection & VM_PROT_WRITE) != 0) { 175 entry->protection &= ~VM_PROT_WRITE; 176 pmap_protect(map->pmap, entry->start, entry->end, 177 entry->protection); 178 } 179 return (false); 180} 181 182static void 183tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t, 184 vm_map_entry_t, void *), void *cb_arg) 185{ 186 struct proc *p; 187 struct vmspace *vm; 188 vm_map_t map; 189 vm_map_entry_t entry; 190 vm_object_t object; 191 struct vnode *vp; 192 int gen; 193 bool terminate; 194 195 terminate = false; 196 sx_slock(&allproc_lock); 197again: 198 gen = allproc_gen; 199 FOREACH_PROC_IN_SYSTEM(p) { 200 PROC_LOCK(p); 201 if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC | 202 P_SYSTEM | P_WEXIT)) != 0) { 203 PROC_UNLOCK(p); 204 continue; 205 } 206 vm = vmspace_acquire_ref(p); 207 _PHOLD_LITE(p); 208 PROC_UNLOCK(p); 209 if (vm == NULL) { 210 PRELE(p); 211 continue; 212 } 213 sx_sunlock(&allproc_lock); 214 map = &vm->vm_map; 215 216 vm_map_lock(map); 217 if (map->busy) 218 vm_map_wait_busy(map); 219 for (entry = map->header.next; entry != &map->header; 220 entry = entry->next) { 221 if ((entry->eflags & (MAP_ENTRY_GUARD | 222 MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 || 223 (entry->max_protection & VM_PROT_WRITE) == 0) 224 continue; 225 object = entry->object.vm_object; 226 if (object == NULL || object->type != OBJT_SWAP || 227 (object->flags & OBJ_TMPFS_NODE) == 0) 228 continue; 229 /* 230 * No need to dig into shadow chain, mapping 231 * of the object not at top is readonly. 232 */ 233 234 VM_OBJECT_RLOCK(object); 235 if (object->type == OBJT_DEAD) { 236 VM_OBJECT_RUNLOCK(object); 237 continue; 238 } 239 MPASS(object->ref_count > 1); 240 if ((object->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) != 241 (OBJ_TMPFS_NODE | OBJ_TMPFS)) { 242 VM_OBJECT_RUNLOCK(object); 243 continue; 244 } 245 vp = object->un_pager.swp.swp_tmpfs; 246 if (vp->v_mount != mp) { 247 VM_OBJECT_RUNLOCK(object); 248 continue; 249 } 250 251 terminate = cb(mp, map, entry, cb_arg); 252 VM_OBJECT_RUNLOCK(object); 253 if (terminate) 254 break; 255 } 256 vm_map_unlock(map); 257 258 vmspace_free(vm); 259 sx_slock(&allproc_lock); 260 PRELE(p); 261 if (terminate) 262 break; 263 } 264 if (!terminate && gen != allproc_gen) 265 goto again; 266 sx_sunlock(&allproc_lock); 267} 268 269static bool 270tmpfs_check_rw_maps(struct mount *mp) 271{ 272 struct tmpfs_check_rw_maps_arg ca; 273 274 ca.found = false; 275 tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca); 276 return (ca.found); 277} 278 279static int 280tmpfs_rw_to_ro(struct mount *mp) 281{ 282 int error, flags; 283 bool forced; 284 285 forced = (mp->mnt_flag & MNT_FORCE) != 0; 286 flags = WRITECLOSE | (forced ? FORCECLOSE : 0); 287 288 if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0) 289 return (error); 290 error = vfs_write_suspend_umnt(mp); 291 if (error != 0) 292 return (error); 293 if (!forced && tmpfs_check_rw_maps(mp)) { 294 error = EBUSY; 295 goto out; 296 } 297 VFS_TO_TMPFS(mp)->tm_ronly = 1; 298 MNT_ILOCK(mp); 299 mp->mnt_flag |= MNT_RDONLY; 300 MNT_IUNLOCK(mp); 301 for (;;) { 302 tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL); 303 tmpfs_update_mtime(mp, false); 304 error = vflush(mp, 0, flags, curthread); 305 if (error != 0) { 306 VFS_TO_TMPFS(mp)->tm_ronly = 0; 307 MNT_ILOCK(mp); 308 mp->mnt_flag &= ~MNT_RDONLY; 309 MNT_IUNLOCK(mp); 310 goto out; 311 } 312 if (!tmpfs_check_rw_maps(mp)) 313 break; 314 } 315out: 316 vfs_write_resume(mp, 0); 317 return (error); 318} 319 320static int 321tmpfs_mount(struct mount *mp) 322{ 323 const size_t nodes_per_page = howmany(PAGE_SIZE, 324 sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node)); 325 struct tmpfs_mount *tmp; 326 struct tmpfs_node *root; 327 int error; 328 bool nonc; 329 /* Size counters. */ 330 u_quad_t pages; 331 off_t nodes_max, size_max, maxfilesize; 332 333 /* Root node attributes. */ 334 uid_t root_uid; 335 gid_t root_gid; 336 mode_t root_mode; 337 338 struct vattr va; 339 340 if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts)) 341 return (EINVAL); 342 343 if (mp->mnt_flag & MNT_UPDATE) { 344 /* Only support update mounts for certain options. */ 345 if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0) 346 return (EOPNOTSUPP); 347 tmp = VFS_TO_TMPFS(mp); 348 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) == 0) { 349 /* 350 * On-the-fly resizing is not supported (yet). We still 351 * need to have "size" listed as "supported", otherwise 352 * trying to update fs that is listed in fstab with size 353 * parameter, say trying to change rw to ro or vice 354 * versa, would cause vfs_filteropt() to bail. 355 */ 356 if (size_max != tmp->tm_size_max) 357 return (EOPNOTSUPP); 358 } 359 if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && 360 !tmp->tm_ronly) { 361 /* RW -> RO */ 362 return (tmpfs_rw_to_ro(mp)); 363 } else if (!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && 364 tmp->tm_ronly) { 365 /* RO -> RW */ 366 tmp->tm_ronly = 0; 367 MNT_ILOCK(mp); 368 mp->mnt_flag &= ~MNT_RDONLY; 369 MNT_IUNLOCK(mp); 370 } 371 return (0); 372 } 373 374 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); 375 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); 376 VOP_UNLOCK(mp->mnt_vnodecovered, 0); 377 if (error) 378 return (error); 379 380 if (mp->mnt_cred->cr_ruid != 0 || 381 vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1) 382 root_gid = va.va_gid; 383 if (mp->mnt_cred->cr_ruid != 0 || 384 vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1) 385 root_uid = va.va_uid; 386 if (mp->mnt_cred->cr_ruid != 0 || 387 vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1) 388 root_mode = va.va_mode; 389 if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0) 390 nodes_max = 0; 391 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0) 392 size_max = 0; 393 if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0) 394 maxfilesize = 0; 395 nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0; 396 397 /* Do not allow mounts if we do not have enough memory to preserve 398 * the minimum reserved pages. */ 399 if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED) 400 return (ENOSPC); 401 402 /* Get the maximum number of memory pages this file system is 403 * allowed to use, based on the maximum size the user passed in 404 * the mount structure. A value of zero is treated as if the 405 * maximum available space was requested. */ 406 if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE || 407 (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX)) 408 pages = SIZE_MAX; 409 else { 410 size_max = roundup(size_max, PAGE_SIZE); 411 pages = howmany(size_max, PAGE_SIZE); 412 } 413 MPASS(pages > 0); 414 415 if (nodes_max <= 3) { 416 if (pages < INT_MAX / nodes_per_page) 417 nodes_max = pages * nodes_per_page; 418 else 419 nodes_max = INT_MAX; 420 } 421 if (nodes_max > INT_MAX) 422 nodes_max = INT_MAX; 423 MPASS(nodes_max >= 3); 424 425 /* Allocate the tmpfs mount structure and fill it. */ 426 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 427 M_TMPFSMNT, M_WAITOK | M_ZERO); 428 429 mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF); 430 tmp->tm_nodes_max = nodes_max; 431 tmp->tm_nodes_inuse = 0; 432 tmp->tm_refcount = 1; 433 tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX; 434 LIST_INIT(&tmp->tm_nodes_used); 435 436 tmp->tm_size_max = size_max; 437 tmp->tm_pages_max = pages; 438 tmp->tm_pages_used = 0; 439 new_unrhdr64(&tmp->tm_ino_unr, 2); 440 tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0; 441 tmp->tm_nonc = nonc; 442 443 /* Allocate the root node. */ 444 error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid, 445 root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root); 446 447 if (error != 0 || root == NULL) { 448 free(tmp, M_TMPFSMNT); 449 return (error); 450 } 451 KASSERT(root->tn_id == 2, 452 ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id)); 453 tmp->tm_root = root; 454 455 MNT_ILOCK(mp); 456 mp->mnt_flag |= MNT_LOCAL; 457 mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED | 458 MNTK_TEXT_REFS; 459 MNT_IUNLOCK(mp); 460 461 mp->mnt_data = tmp; 462 mp->mnt_stat.f_namemax = MAXNAMLEN; 463 vfs_getnewfsid(mp); 464 vfs_mountedfrom(mp, "tmpfs"); 465 466 return 0; 467} 468 469/* ARGSUSED2 */ 470static int 471tmpfs_unmount(struct mount *mp, int mntflags) 472{ 473 struct tmpfs_mount *tmp; 474 struct tmpfs_node *node; 475 int error, flags; 476 477 flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0; 478 tmp = VFS_TO_TMPFS(mp); 479 480 /* Stop writers */ 481 error = vfs_write_suspend_umnt(mp); 482 if (error != 0) 483 return (error); 484 /* 485 * At this point, nodes cannot be destroyed by any other 486 * thread because write suspension is started. 487 */ 488 489 for (;;) { 490 error = vflush(mp, 0, flags, curthread); 491 if (error != 0) { 492 vfs_write_resume(mp, VR_START_WRITE); 493 return (error); 494 } 495 MNT_ILOCK(mp); 496 if (mp->mnt_nvnodelistsize == 0) { 497 MNT_IUNLOCK(mp); 498 break; 499 } 500 MNT_IUNLOCK(mp); 501 if ((mntflags & MNT_FORCE) == 0) { 502 vfs_write_resume(mp, VR_START_WRITE); 503 return (EBUSY); 504 } 505 } 506 507 TMPFS_LOCK(tmp); 508 while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) { 509 TMPFS_NODE_LOCK(node); 510 if (node->tn_type == VDIR) 511 tmpfs_dir_destroy(tmp, node); 512 if (tmpfs_free_node_locked(tmp, node, true)) 513 TMPFS_LOCK(tmp); 514 else 515 TMPFS_NODE_UNLOCK(node); 516 } 517 518 mp->mnt_data = NULL; 519 tmpfs_free_tmp(tmp); 520 vfs_write_resume(mp, VR_START_WRITE); 521 522 MNT_ILOCK(mp); 523 mp->mnt_flag &= ~MNT_LOCAL; 524 MNT_IUNLOCK(mp); 525 526 return (0); 527} 528 529void 530tmpfs_free_tmp(struct tmpfs_mount *tmp) 531{ 532 TMPFS_MP_ASSERT_LOCKED(tmp); 533 MPASS(tmp->tm_refcount > 0); 534 535 tmp->tm_refcount--; 536 if (tmp->tm_refcount > 0) { 537 TMPFS_UNLOCK(tmp); 538 return; 539 } 540 TMPFS_UNLOCK(tmp); 541 542 mtx_destroy(&tmp->tm_allnode_lock); 543 MPASS(tmp->tm_pages_used == 0); 544 MPASS(tmp->tm_nodes_inuse == 0); 545 546 free(tmp, M_TMPFSMNT); 547} 548 549static int 550tmpfs_root(struct mount *mp, int flags, struct vnode **vpp) 551{ 552 int error; 553 554 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp); 555 if (error == 0) 556 (*vpp)->v_vflag |= VV_ROOT; 557 return (error); 558} 559 560static int 561tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, 562 struct vnode **vpp) 563{ 564 struct tmpfs_fid_data tfd; 565 struct tmpfs_mount *tmp; 566 struct tmpfs_node *node; 567 int error; 568 569 if (fhp->fid_len != sizeof(tfd)) 570 return (EINVAL); 571 572 /* 573 * Copy from fid_data onto the stack to avoid unaligned pointer use. 574 * See the comment in sys/mount.h on struct fid for details. 575 */ 576 memcpy(&tfd, fhp->fid_data, fhp->fid_len); 577 578 tmp = VFS_TO_TMPFS(mp); 579 580 if (tfd.tfd_id >= tmp->tm_nodes_max) 581 return (EINVAL); 582 583 TMPFS_LOCK(tmp); 584 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 585 if (node->tn_id == tfd.tfd_id && 586 node->tn_gen == tfd.tfd_gen) { 587 tmpfs_ref_node(node); 588 break; 589 } 590 } 591 TMPFS_UNLOCK(tmp); 592 593 if (node != NULL) { 594 error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp); 595 tmpfs_free_node(tmp, node); 596 } else 597 error = EINVAL; 598 return (error); 599} 600 601/* ARGSUSED2 */ 602static int 603tmpfs_statfs(struct mount *mp, struct statfs *sbp) 604{ 605 struct tmpfs_mount *tmp; 606 size_t used; 607 608 tmp = VFS_TO_TMPFS(mp); 609 610 sbp->f_iosize = PAGE_SIZE; 611 sbp->f_bsize = PAGE_SIZE; 612 613 used = tmpfs_pages_used(tmp); 614 if (tmp->tm_pages_max != ULONG_MAX) 615 sbp->f_blocks = tmp->tm_pages_max; 616 else 617 sbp->f_blocks = used + tmpfs_mem_avail(); 618 if (sbp->f_blocks <= used) 619 sbp->f_bavail = 0; 620 else 621 sbp->f_bavail = sbp->f_blocks - used; 622 sbp->f_bfree = sbp->f_bavail; 623 used = tmp->tm_nodes_inuse; 624 sbp->f_files = tmp->tm_nodes_max; 625 if (sbp->f_files <= used) 626 sbp->f_ffree = 0; 627 else 628 sbp->f_ffree = sbp->f_files - used; 629 /* sbp->f_owner = tmp->tn_uid; */ 630 631 return 0; 632} 633 634static int 635tmpfs_sync(struct mount *mp, int waitfor) 636{ 637 638 if (waitfor == MNT_SUSPEND) { 639 MNT_ILOCK(mp); 640 mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED; 641 MNT_IUNLOCK(mp); 642 } else if (waitfor == MNT_LAZY) { 643 tmpfs_update_mtime(mp, true); 644 } 645 return (0); 646} 647 648/* 649 * The presence of a susp_clean method tells the VFS to track writes. 650 */ 651static void 652tmpfs_susp_clean(struct mount *mp __unused) 653{ 654} 655 656static int 657tmpfs_init(struct vfsconf *conf) 658{ 659 tmpfs_subr_init(); 660 return (0); 661} 662 663static int 664tmpfs_uninit(struct vfsconf *conf) 665{ 666 tmpfs_subr_uninit(); 667 return (0); 668} 669 670/* 671 * tmpfs vfs operations. 672 */ 673struct vfsops tmpfs_vfsops = { 674 .vfs_mount = tmpfs_mount, 675 .vfs_unmount = tmpfs_unmount, 676 .vfs_root = tmpfs_root, 677 .vfs_statfs = tmpfs_statfs, 678 .vfs_fhtovp = tmpfs_fhtovp, 679 .vfs_sync = tmpfs_sync, 680 .vfs_susp_clean = tmpfs_susp_clean, 681 .vfs_init = tmpfs_init, 682 .vfs_uninit = tmpfs_uninit, 683}; 684VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL); 685