Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/fs/tmpfs/tmpfs_vfsops.c
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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 46 #include "opt_tmpfs.h" 47 48 #include <sys/cdefs.h> 49 __FBSDID("$FreeBSD$"); 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/dirent.h> 54 #include <sys/file.h> 55 #include <sys/limits.h> 56 #include <sys/lock.h> 57 #include <sys/mount.h> 58 #include <sys/mutex.h> 59 #include <sys/proc.h> 60 #include <sys/jail.h> 61 #include <sys/kernel.h> 62 #include <sys/rwlock.h> 63 #include <sys/stat.h> 64 #include <sys/sx.h> 65 #include <sys/sysctl.h> 66 #include <sys/vnode.h> 67 68 #include <vm/vm.h> 69 #include <vm/vm_param.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_extern.h> 72 #include <vm/vm_map.h> 73 #include <vm/vm_object.h> 74 #include <vm/vm_param.h> 75 76 #include <fs/tmpfs/tmpfs.h> 77 78 /* 79 * Default permission for root node 80 */ 81 #define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) 82 83 static MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); 84 MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names"); 85 86 static int tmpfs_mount(struct mount *); 87 static int tmpfs_unmount(struct mount *, int); 88 static int tmpfs_root(struct mount *, int flags, struct vnode **); 89 static int tmpfs_fhtovp(struct mount *, struct fid *, int, 90 struct vnode **); 91 static int tmpfs_statfs(struct mount *, struct statfs *); 92 93 static const char *tmpfs_opts[] = { 94 "from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export", 95 "union", "nonc", "nomtime", NULL 96 }; 97 98 static const char *tmpfs_updateopts[] = { 99 "from", "export", "nomtime", "size", NULL 100 }; 101 102 static int 103 tmpfs_update_mtime_lazy_filter(struct vnode *vp, void *arg) 104 { 105 struct vm_object *obj; 106 107 if (vp->v_type != VREG) 108 return (0); 109 110 obj = atomic_load_ptr(&vp->v_object); 111 if (obj == NULL) 112 return (0); 113 114 return (vm_object_mightbedirty_(obj)); 115 } 116 117 static void 118 tmpfs_update_mtime_lazy(struct mount *mp) 119 { 120 struct vnode *vp, *mvp; 121 122 MNT_VNODE_FOREACH_LAZY(vp, mp, mvp, tmpfs_update_mtime_lazy_filter, NULL) { 123 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) 124 continue; 125 tmpfs_check_mtime(vp); 126 vput(vp); 127 } 128 } 129 130 static void 131 tmpfs_update_mtime_all(struct mount *mp) 132 { 133 struct vnode *vp, *mvp; 134 135 if (VFS_TO_TMPFS(mp)->tm_nomtime) 136 return; 137 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 138 if (vp->v_type != VREG) { 139 VI_UNLOCK(vp); 140 continue; 141 } 142 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK) != 0) 143 continue; 144 tmpfs_check_mtime(vp); 145 tmpfs_update(vp); 146 vput(vp); 147 } 148 } 149 150 struct tmpfs_check_rw_maps_arg { 151 bool found; 152 }; 153 154 static bool 155 tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused, 156 vm_map_entry_t entry __unused, void *arg) 157 { 158 struct tmpfs_check_rw_maps_arg *a; 159 160 a = arg; 161 a->found = true; 162 return (true); 163 } 164 165 /* 166 * Revoke write permissions from all mappings of regular files 167 * belonging to the specified tmpfs mount. 168 */ 169 static bool 170 tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map, 171 vm_map_entry_t entry, void *arg __unused) 172 { 173 174 /* 175 * XXXKIB: might be invalidate the mapping 176 * instead ? The process is not going to be 177 * happy in any case. 178 */ 179 entry->max_protection &= ~VM_PROT_WRITE; 180 if ((entry->protection & VM_PROT_WRITE) != 0) { 181 entry->protection &= ~VM_PROT_WRITE; 182 pmap_protect(map->pmap, entry->start, entry->end, 183 entry->protection); 184 } 185 return (false); 186 } 187 188 static void 189 tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t, 190 vm_map_entry_t, void *), void *cb_arg) 191 { 192 struct proc *p; 193 struct vmspace *vm; 194 vm_map_t map; 195 vm_map_entry_t entry; 196 vm_object_t object; 197 struct vnode *vp; 198 int gen; 199 bool terminate; 200 201 terminate = false; 202 sx_slock(&allproc_lock); 203 again: 204 gen = allproc_gen; 205 FOREACH_PROC_IN_SYSTEM(p) { 206 PROC_LOCK(p); 207 if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC | 208 P_SYSTEM | P_WEXIT)) != 0) { 209 PROC_UNLOCK(p); 210 continue; 211 } 212 vm = vmspace_acquire_ref(p); 213 _PHOLD_LITE(p); 214 PROC_UNLOCK(p); 215 if (vm == NULL) { 216 PRELE(p); 217 continue; 218 } 219 sx_sunlock(&allproc_lock); 220 map = &vm->vm_map; 221 222 vm_map_lock(map); 223 if (map->busy) 224 vm_map_wait_busy(map); 225 VM_MAP_ENTRY_FOREACH(entry, map) { 226 if ((entry->eflags & (MAP_ENTRY_GUARD | 227 MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 || 228 (entry->max_protection & VM_PROT_WRITE) == 0) 229 continue; 230 object = entry->object.vm_object; 231 if (object == NULL || object->type != tmpfs_pager_type) 232 continue; 233 /* 234 * No need to dig into shadow chain, mapping 235 * of the object not at top is readonly. 236 */ 237 238 VM_OBJECT_RLOCK(object); 239 if (object->type == OBJT_DEAD) { 240 VM_OBJECT_RUNLOCK(object); 241 continue; 242 } 243 MPASS(object->ref_count > 1); 244 if ((object->flags & OBJ_TMPFS) == 0) { 245 VM_OBJECT_RUNLOCK(object); 246 continue; 247 } 248 vp = object->un_pager.swp.swp_tmpfs; 249 if (vp->v_mount != mp) { 250 VM_OBJECT_RUNLOCK(object); 251 continue; 252 } 253 254 terminate = cb(mp, map, entry, cb_arg); 255 VM_OBJECT_RUNLOCK(object); 256 if (terminate) 257 break; 258 } 259 vm_map_unlock(map); 260 261 vmspace_free(vm); 262 sx_slock(&allproc_lock); 263 PRELE(p); 264 if (terminate) 265 break; 266 } 267 if (!terminate && gen != allproc_gen) 268 goto again; 269 sx_sunlock(&allproc_lock); 270 } 271 272 static bool 273 tmpfs_check_rw_maps(struct mount *mp) 274 { 275 struct tmpfs_check_rw_maps_arg ca; 276 277 ca.found = false; 278 tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca); 279 return (ca.found); 280 } 281 282 static int 283 tmpfs_rw_to_ro(struct mount *mp) 284 { 285 int error, flags; 286 bool forced; 287 288 forced = (mp->mnt_flag & MNT_FORCE) != 0; 289 flags = WRITECLOSE | (forced ? FORCECLOSE : 0); 290 291 if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0) 292 return (error); 293 error = vfs_write_suspend_umnt(mp); 294 if (error != 0) 295 return (error); 296 if (!forced && tmpfs_check_rw_maps(mp)) { 297 error = EBUSY; 298 goto out; 299 } 300 VFS_TO_TMPFS(mp)->tm_ronly = 1; 301 MNT_ILOCK(mp); 302 mp->mnt_flag |= MNT_RDONLY; 303 MNT_IUNLOCK(mp); 304 for (;;) { 305 tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL); 306 tmpfs_update_mtime_all(mp); 307 error = vflush(mp, 0, flags, curthread); 308 if (error != 0) { 309 VFS_TO_TMPFS(mp)->tm_ronly = 0; 310 MNT_ILOCK(mp); 311 mp->mnt_flag &= ~MNT_RDONLY; 312 MNT_IUNLOCK(mp); 313 goto out; 314 } 315 if (!tmpfs_check_rw_maps(mp)) 316 break; 317 } 318 out: 319 vfs_write_resume(mp, 0); 320 return (error); 321 } 322 323 static int 324 tmpfs_mount(struct mount *mp) 325 { 326 const size_t nodes_per_page = howmany(PAGE_SIZE, 327 sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node)); 328 struct tmpfs_mount *tmp; 329 struct tmpfs_node *root; 330 int error; 331 bool nomtime, nonc; 332 /* Size counters. */ 333 u_quad_t pages; 334 off_t nodes_max, size_max, maxfilesize; 335 336 /* Root node attributes. */ 337 uid_t root_uid; 338 gid_t root_gid; 339 mode_t root_mode; 340 341 struct vattr va; 342 343 if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts)) 344 return (EINVAL); 345 346 if (mp->mnt_flag & MNT_UPDATE) { 347 /* Only support update mounts for certain options. */ 348 if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0) 349 return (EOPNOTSUPP); 350 tmp = VFS_TO_TMPFS(mp); 351 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) == 0) { 352 /* 353 * On-the-fly resizing is not supported (yet). We still 354 * need to have "size" listed as "supported", otherwise 355 * trying to update fs that is listed in fstab with size 356 * parameter, say trying to change rw to ro or vice 357 * versa, would cause vfs_filteropt() to bail. 358 */ 359 if (size_max != tmp->tm_size_max) 360 return (EOPNOTSUPP); 361 } 362 if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && 363 !tmp->tm_ronly) { 364 /* RW -> RO */ 365 return (tmpfs_rw_to_ro(mp)); 366 } else if (!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && 367 tmp->tm_ronly) { 368 /* RO -> RW */ 369 tmp->tm_ronly = 0; 370 MNT_ILOCK(mp); 371 mp->mnt_flag &= ~MNT_RDONLY; 372 MNT_IUNLOCK(mp); 373 } 374 tmp->tm_nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, 375 0) == 0; 376 MNT_ILOCK(mp); 377 if ((mp->mnt_flag & MNT_UNION) == 0) { 378 mp->mnt_kern_flag |= MNTK_FPLOOKUP; 379 } else { 380 mp->mnt_kern_flag &= ~MNTK_FPLOOKUP; 381 } 382 MNT_IUNLOCK(mp); 383 return (0); 384 } 385 386 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); 387 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); 388 VOP_UNLOCK(mp->mnt_vnodecovered); 389 if (error) 390 return (error); 391 392 if (mp->mnt_cred->cr_ruid != 0 || 393 vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1) 394 root_gid = va.va_gid; 395 if (mp->mnt_cred->cr_ruid != 0 || 396 vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1) 397 root_uid = va.va_uid; 398 if (mp->mnt_cred->cr_ruid != 0 || 399 vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1) 400 root_mode = va.va_mode; 401 if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0) 402 nodes_max = 0; 403 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0) 404 size_max = 0; 405 if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0) 406 maxfilesize = 0; 407 nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0; 408 nomtime = vfs_getopt(mp->mnt_optnew, "nomtime", NULL, NULL) == 0; 409 410 /* Do not allow mounts if we do not have enough memory to preserve 411 * the minimum reserved pages. */ 412 if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED) 413 return (ENOSPC); 414 415 /* Get the maximum number of memory pages this file system is 416 * allowed to use, based on the maximum size the user passed in 417 * the mount structure. A value of zero is treated as if the 418 * maximum available space was requested. */ 419 if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE || 420 (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX)) 421 pages = SIZE_MAX; 422 else { 423 size_max = roundup(size_max, PAGE_SIZE); 424 pages = howmany(size_max, PAGE_SIZE); 425 } 426 MPASS(pages > 0); 427 428 if (nodes_max <= 3) { 429 if (pages < INT_MAX / nodes_per_page) 430 nodes_max = pages * nodes_per_page; 431 else 432 nodes_max = INT_MAX; 433 } 434 if (nodes_max > INT_MAX) 435 nodes_max = INT_MAX; 436 MPASS(nodes_max >= 3); 437 438 /* Allocate the tmpfs mount structure and fill it. */ 439 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 440 M_TMPFSMNT, M_WAITOK | M_ZERO); 441 442 mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF); 443 tmp->tm_nodes_max = nodes_max; 444 tmp->tm_nodes_inuse = 0; 445 tmp->tm_refcount = 1; 446 tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX; 447 LIST_INIT(&tmp->tm_nodes_used); 448 449 tmp->tm_size_max = size_max; 450 tmp->tm_pages_max = pages; 451 tmp->tm_pages_used = 0; 452 new_unrhdr64(&tmp->tm_ino_unr, 2); 453 tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0; 454 tmp->tm_nonc = nonc; 455 tmp->tm_nomtime = nomtime; 456 457 /* Allocate the root node. */ 458 error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid, 459 root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root); 460 461 if (error != 0 || root == NULL) { 462 free(tmp, M_TMPFSMNT); 463 return (error); 464 } 465 KASSERT(root->tn_id == 2, 466 ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id)); 467 tmp->tm_root = root; 468 469 MNT_ILOCK(mp); 470 mp->mnt_flag |= MNT_LOCAL; 471 mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED | 472 MNTK_TEXT_REFS | MNTK_NOMSYNC; 473 if (!nonc && (mp->mnt_flag & MNT_UNION) == 0) 474 mp->mnt_kern_flag |= MNTK_FPLOOKUP; 475 MNT_IUNLOCK(mp); 476 477 mp->mnt_data = tmp; 478 mp->mnt_stat.f_namemax = MAXNAMLEN; 479 vfs_getnewfsid(mp); 480 vfs_mountedfrom(mp, "tmpfs"); 481 482 return (0); 483 } 484 485 /* ARGSUSED2 */ 486 static int 487 tmpfs_unmount(struct mount *mp, int mntflags) 488 { 489 struct tmpfs_mount *tmp; 490 struct tmpfs_node *node; 491 int error, flags; 492 493 flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0; 494 tmp = VFS_TO_TMPFS(mp); 495 496 /* Stop writers */ 497 error = vfs_write_suspend_umnt(mp); 498 if (error != 0) 499 return (error); 500 /* 501 * At this point, nodes cannot be destroyed by any other 502 * thread because write suspension is started. 503 */ 504 505 for (;;) { 506 error = vflush(mp, 0, flags, curthread); 507 if (error != 0) { 508 vfs_write_resume(mp, VR_START_WRITE); 509 return (error); 510 } 511 MNT_ILOCK(mp); 512 if (mp->mnt_nvnodelistsize == 0) { 513 MNT_IUNLOCK(mp); 514 break; 515 } 516 MNT_IUNLOCK(mp); 517 if ((mntflags & MNT_FORCE) == 0) { 518 vfs_write_resume(mp, VR_START_WRITE); 519 return (EBUSY); 520 } 521 } 522 523 TMPFS_LOCK(tmp); 524 while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) { 525 TMPFS_NODE_LOCK(node); 526 if (node->tn_type == VDIR) 527 tmpfs_dir_destroy(tmp, node); 528 if (tmpfs_free_node_locked(tmp, node, true)) 529 TMPFS_LOCK(tmp); 530 else 531 TMPFS_NODE_UNLOCK(node); 532 } 533 534 mp->mnt_data = NULL; 535 tmpfs_free_tmp(tmp); 536 vfs_write_resume(mp, VR_START_WRITE); 537 538 MNT_ILOCK(mp); 539 mp->mnt_flag &= ~MNT_LOCAL; 540 MNT_IUNLOCK(mp); 541 542 return (0); 543 } 544 545 void 546 tmpfs_free_tmp(struct tmpfs_mount *tmp) 547 { 548 TMPFS_MP_ASSERT_LOCKED(tmp); 549 MPASS(tmp->tm_refcount > 0); 550 551 tmp->tm_refcount--; 552 if (tmp->tm_refcount > 0) { 553 TMPFS_UNLOCK(tmp); 554 return; 555 } 556 TMPFS_UNLOCK(tmp); 557 558 mtx_destroy(&tmp->tm_allnode_lock); 559 MPASS(tmp->tm_pages_used == 0); 560 MPASS(tmp->tm_nodes_inuse == 0); 561 562 free(tmp, M_TMPFSMNT); 563 } 564 565 static int 566 tmpfs_root(struct mount *mp, int flags, struct vnode **vpp) 567 { 568 int error; 569 570 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp); 571 if (error == 0) 572 (*vpp)->v_vflag |= VV_ROOT; 573 return (error); 574 } 575 576 static int 577 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, 578 struct vnode **vpp) 579 { 580 struct tmpfs_fid_data tfd; 581 struct tmpfs_mount *tmp; 582 struct tmpfs_node *node; 583 int error; 584 585 if (fhp->fid_len != sizeof(tfd)) 586 return (EINVAL); 587 588 /* 589 * Copy from fid_data onto the stack to avoid unaligned pointer use. 590 * See the comment in sys/mount.h on struct fid for details. 591 */ 592 memcpy(&tfd, fhp->fid_data, fhp->fid_len); 593 594 tmp = VFS_TO_TMPFS(mp); 595 596 if (tfd.tfd_id >= tmp->tm_nodes_max) 597 return (EINVAL); 598 599 TMPFS_LOCK(tmp); 600 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 601 if (node->tn_id == tfd.tfd_id && 602 node->tn_gen == tfd.tfd_gen) { 603 tmpfs_ref_node(node); 604 break; 605 } 606 } 607 TMPFS_UNLOCK(tmp); 608 609 if (node != NULL) { 610 error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp); 611 tmpfs_free_node(tmp, node); 612 } else 613 error = EINVAL; 614 return (error); 615 } 616 617 /* ARGSUSED2 */ 618 static int 619 tmpfs_statfs(struct mount *mp, struct statfs *sbp) 620 { 621 struct tmpfs_mount *tmp; 622 size_t used; 623 624 tmp = VFS_TO_TMPFS(mp); 625 626 sbp->f_iosize = PAGE_SIZE; 627 sbp->f_bsize = PAGE_SIZE; 628 629 used = tmpfs_pages_used(tmp); 630 if (tmp->tm_pages_max != ULONG_MAX) 631 sbp->f_blocks = tmp->tm_pages_max; 632 else 633 sbp->f_blocks = used + tmpfs_mem_avail(); 634 if (sbp->f_blocks <= used) 635 sbp->f_bavail = 0; 636 else 637 sbp->f_bavail = sbp->f_blocks - used; 638 sbp->f_bfree = sbp->f_bavail; 639 used = tmp->tm_nodes_inuse; 640 sbp->f_files = tmp->tm_nodes_max; 641 if (sbp->f_files <= used) 642 sbp->f_ffree = 0; 643 else 644 sbp->f_ffree = sbp->f_files - used; 645 /* sbp->f_owner = tmp->tn_uid; */ 646 647 return (0); 648 } 649 650 static int 651 tmpfs_sync(struct mount *mp, int waitfor) 652 { 653 654 if (waitfor == MNT_SUSPEND) { 655 MNT_ILOCK(mp); 656 mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED; 657 MNT_IUNLOCK(mp); 658 } else if (waitfor == MNT_LAZY) { 659 tmpfs_update_mtime_lazy(mp); 660 } 661 return (0); 662 } 663 664 static int 665 tmpfs_init(struct vfsconf *conf) 666 { 667 int res; 668 669 res = tmpfs_subr_init(); 670 if (res != 0) 671 return (res); 672 memcpy(&tmpfs_fnops, &vnops, sizeof(struct fileops)); 673 tmpfs_fnops.fo_close = tmpfs_fo_close; 674 return (0); 675 } 676 677 static int 678 tmpfs_uninit(struct vfsconf *conf) 679 { 680 tmpfs_subr_uninit(); 681 return (0); 682 } 683 684 /* 685 * tmpfs vfs operations. 686 */ 687 struct vfsops tmpfs_vfsops = { 688 .vfs_mount = tmpfs_mount, 689 .vfs_unmount = tmpfs_unmount, 690 .vfs_root = vfs_cache_root, 691 .vfs_cachedroot = tmpfs_root, 692 .vfs_statfs = tmpfs_statfs, 693 .vfs_fhtovp = tmpfs_fhtovp, 694 .vfs_sync = tmpfs_sync, 695 .vfs_init = tmpfs_init, 696 .vfs_uninit = tmpfs_uninit, 697 }; 698 VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);
Cache object: 80f98cd85d24db9ad3d74c9e5050e5e5
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