Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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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 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 9 * 2005 program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Efficient memory file system. 35 * 36 * tmpfs is a file system that uses FreeBSD's virtual memory 37 * sub-system to store file data and metadata in an efficient way. 38 * This means that it does not follow the structure of an on-disk file 39 * system because it simply does not need to. Instead, it uses 40 * memory-specific data structures and algorithms to automatically 41 * allocate and release resources. 42 */ 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include <sys/param.h> 47 #include <sys/limits.h> 48 #include <sys/lock.h> 49 #include <sys/mutex.h> 50 #include <sys/proc.h> 51 #include <sys/jail.h> 52 #include <sys/kernel.h> 53 #include <sys/rwlock.h> 54 #include <sys/stat.h> 55 #include <sys/sx.h> 56 #include <sys/sysctl.h> 57 58 #include <vm/vm.h> 59 #include <vm/vm_param.h> 60 #include <vm/pmap.h> 61 #include <vm/vm_extern.h> 62 #include <vm/vm_map.h> 63 #include <vm/vm_object.h> 64 #include <vm/vm_param.h> 65 66 #include <fs/tmpfs/tmpfs.h> 67 68 /* 69 * Default permission for root node 70 */ 71 #define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) 72 73 MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures"); 74 MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names"); 75 76 static int tmpfs_mount(struct mount *); 77 static int tmpfs_unmount(struct mount *, int); 78 static int tmpfs_root(struct mount *, int flags, struct vnode **); 79 static int tmpfs_fhtovp(struct mount *, struct fid *, int, 80 struct vnode **); 81 static int tmpfs_statfs(struct mount *, struct statfs *); 82 static void tmpfs_susp_clean(struct mount *); 83 84 static const char *tmpfs_opts[] = { 85 "from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export", 86 "union", "nonc", NULL 87 }; 88 89 static const char *tmpfs_updateopts[] = { 90 "from", "export", "size", NULL 91 }; 92 93 static int 94 tmpfs_node_ctor(void *mem, int size, void *arg, int flags) 95 { 96 struct tmpfs_node *node = (struct tmpfs_node *)mem; 97 98 node->tn_gen++; 99 node->tn_size = 0; 100 node->tn_status = 0; 101 node->tn_flags = 0; 102 node->tn_links = 0; 103 node->tn_vnode = NULL; 104 node->tn_vpstate = 0; 105 106 return (0); 107 } 108 109 static void 110 tmpfs_node_dtor(void *mem, int size, void *arg) 111 { 112 struct tmpfs_node *node = (struct tmpfs_node *)mem; 113 node->tn_type = VNON; 114 } 115 116 static int 117 tmpfs_node_init(void *mem, int size, int flags) 118 { 119 struct tmpfs_node *node = (struct tmpfs_node *)mem; 120 node->tn_id = 0; 121 122 mtx_init(&node->tn_interlock, "tmpfs node interlock", NULL, MTX_DEF); 123 node->tn_gen = arc4random(); 124 125 return (0); 126 } 127 128 static void 129 tmpfs_node_fini(void *mem, int size) 130 { 131 struct tmpfs_node *node = (struct tmpfs_node *)mem; 132 133 mtx_destroy(&node->tn_interlock); 134 } 135 136 /* 137 * Handle updates of time from writes to mmaped regions. Use 138 * MNT_VNODE_FOREACH_ALL instead of MNT_VNODE_FOREACH_ACTIVE, since 139 * unmap of the tmpfs-backed vnode does not call vinactive(), due to 140 * vm object type is OBJT_SWAP. 141 * If lazy, only handle delayed update of mtime due to the writes to 142 * mapped files. 143 */ 144 static void 145 tmpfs_update_mtime(struct mount *mp, bool lazy) 146 { 147 struct vnode *vp, *mvp; 148 struct vm_object *obj; 149 150 MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { 151 if (vp->v_type != VREG) { 152 VI_UNLOCK(vp); 153 continue; 154 } 155 obj = vp->v_object; 156 KASSERT((obj->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) == 157 (OBJ_TMPFS_NODE | OBJ_TMPFS), ("non-tmpfs obj")); 158 159 /* 160 * In lazy case, do unlocked read, avoid taking vnode 161 * lock if not needed. Lost update will be handled on 162 * the next call. 163 * For non-lazy case, we must flush all pending 164 * metadata changes now. 165 */ 166 if (!lazy || (obj->flags & OBJ_TMPFS_DIRTY) != 0) { 167 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, 168 curthread) != 0) 169 continue; 170 tmpfs_check_mtime(vp); 171 if (!lazy) 172 tmpfs_update(vp); 173 vput(vp); 174 } else { 175 VI_UNLOCK(vp); 176 continue; 177 } 178 } 179 } 180 181 struct tmpfs_check_rw_maps_arg { 182 bool found; 183 }; 184 185 static bool 186 tmpfs_check_rw_maps_cb(struct mount *mp __unused, vm_map_t map __unused, 187 vm_map_entry_t entry __unused, void *arg) 188 { 189 struct tmpfs_check_rw_maps_arg *a; 190 191 a = arg; 192 a->found = true; 193 return (true); 194 } 195 196 /* 197 * Revoke write permissions from all mappings of regular files 198 * belonging to the specified tmpfs mount. 199 */ 200 static bool 201 tmpfs_revoke_rw_maps_cb(struct mount *mp __unused, vm_map_t map, 202 vm_map_entry_t entry, void *arg __unused) 203 { 204 205 /* 206 * XXXKIB: might be invalidate the mapping 207 * instead ? The process is not going to be 208 * happy in any case. 209 */ 210 entry->max_protection &= ~VM_PROT_WRITE; 211 if ((entry->protection & VM_PROT_WRITE) != 0) { 212 entry->protection &= ~VM_PROT_WRITE; 213 pmap_protect(map->pmap, entry->start, entry->end, 214 entry->protection); 215 } 216 return (false); 217 } 218 219 static void 220 tmpfs_all_rw_maps(struct mount *mp, bool (*cb)(struct mount *mp, vm_map_t, 221 vm_map_entry_t, void *), void *cb_arg) 222 { 223 struct proc *p; 224 struct vmspace *vm; 225 vm_map_t map; 226 vm_map_entry_t entry; 227 vm_object_t object; 228 struct vnode *vp; 229 int gen; 230 bool terminate; 231 232 terminate = false; 233 sx_slock(&allproc_lock); 234 again: 235 gen = allproc_gen; 236 FOREACH_PROC_IN_SYSTEM(p) { 237 PROC_LOCK(p); 238 if (p->p_state != PRS_NORMAL || (p->p_flag & (P_INEXEC | 239 P_SYSTEM | P_WEXIT)) != 0) { 240 PROC_UNLOCK(p); 241 continue; 242 } 243 vm = vmspace_acquire_ref(p); 244 _PHOLD_LITE(p); 245 PROC_UNLOCK(p); 246 if (vm == NULL) { 247 PRELE(p); 248 continue; 249 } 250 sx_sunlock(&allproc_lock); 251 map = &vm->vm_map; 252 253 vm_map_lock(map); 254 if (map->busy) 255 vm_map_wait_busy(map); 256 for (entry = map->header.next; entry != &map->header; 257 entry = entry->next) { 258 if ((entry->eflags & (MAP_ENTRY_GUARD | 259 MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_COW)) != 0 || 260 (entry->max_protection & VM_PROT_WRITE) == 0) 261 continue; 262 object = entry->object.vm_object; 263 if (object == NULL || object->type != OBJT_SWAP || 264 (object->flags & OBJ_TMPFS_NODE) == 0) 265 continue; 266 /* 267 * No need to dig into shadow chain, mapping 268 * of the object not at top is readonly. 269 */ 270 271 VM_OBJECT_RLOCK(object); 272 if (object->type == OBJT_DEAD) { 273 VM_OBJECT_RUNLOCK(object); 274 continue; 275 } 276 MPASS(object->ref_count > 1); 277 if ((object->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) != 278 (OBJ_TMPFS_NODE | OBJ_TMPFS)) { 279 VM_OBJECT_RUNLOCK(object); 280 continue; 281 } 282 vp = object->un_pager.swp.swp_tmpfs; 283 if (vp->v_mount != mp) { 284 VM_OBJECT_RUNLOCK(object); 285 continue; 286 } 287 288 terminate = cb(mp, map, entry, cb_arg); 289 VM_OBJECT_RUNLOCK(object); 290 if (terminate) 291 break; 292 } 293 vm_map_unlock(map); 294 295 vmspace_free(vm); 296 sx_slock(&allproc_lock); 297 PRELE(p); 298 if (terminate) 299 break; 300 } 301 if (!terminate && gen != allproc_gen) 302 goto again; 303 sx_sunlock(&allproc_lock); 304 } 305 306 static bool 307 tmpfs_check_rw_maps(struct mount *mp) 308 { 309 struct tmpfs_check_rw_maps_arg ca; 310 311 ca.found = false; 312 tmpfs_all_rw_maps(mp, tmpfs_check_rw_maps_cb, &ca); 313 return (ca.found); 314 } 315 316 static int 317 tmpfs_rw_to_ro(struct mount *mp) 318 { 319 int error, flags; 320 bool forced; 321 322 forced = (mp->mnt_flag & MNT_FORCE) != 0; 323 flags = WRITECLOSE | (forced ? FORCECLOSE : 0); 324 325 if ((error = vn_start_write(NULL, &mp, V_WAIT)) != 0) 326 return (error); 327 error = vfs_write_suspend_umnt(mp); 328 if (error != 0) 329 return (error); 330 if (!forced && tmpfs_check_rw_maps(mp)) { 331 error = EBUSY; 332 goto out; 333 } 334 VFS_TO_TMPFS(mp)->tm_ronly = 1; 335 MNT_ILOCK(mp); 336 mp->mnt_flag |= MNT_RDONLY; 337 MNT_IUNLOCK(mp); 338 for (;;) { 339 tmpfs_all_rw_maps(mp, tmpfs_revoke_rw_maps_cb, NULL); 340 tmpfs_update_mtime(mp, false); 341 error = vflush(mp, 0, flags, curthread); 342 if (error != 0) { 343 VFS_TO_TMPFS(mp)->tm_ronly = 0; 344 MNT_ILOCK(mp); 345 mp->mnt_flag &= ~MNT_RDONLY; 346 MNT_IUNLOCK(mp); 347 goto out; 348 } 349 if (!tmpfs_check_rw_maps(mp)) 350 break; 351 } 352 out: 353 vfs_write_resume(mp, 0); 354 return (error); 355 } 356 357 static int 358 tmpfs_mount(struct mount *mp) 359 { 360 const size_t nodes_per_page = howmany(PAGE_SIZE, 361 sizeof(struct tmpfs_dirent) + sizeof(struct tmpfs_node)); 362 struct tmpfs_mount *tmp; 363 struct tmpfs_node *root; 364 struct thread *td = curthread; 365 int error; 366 bool nonc; 367 /* Size counters. */ 368 u_quad_t pages; 369 off_t nodes_max, size_max, maxfilesize; 370 371 /* Root node attributes. */ 372 uid_t root_uid; 373 gid_t root_gid; 374 mode_t root_mode; 375 376 struct vattr va; 377 378 if (!prison_allow(td->td_ucred, PR_ALLOW_MOUNT_TMPFS)) 379 return (EPERM); 380 381 if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts)) 382 return (EINVAL); 383 384 if (mp->mnt_flag & MNT_UPDATE) { 385 /* Only support update mounts for certain options. */ 386 if (vfs_filteropt(mp->mnt_optnew, tmpfs_updateopts) != 0) 387 return (EOPNOTSUPP); 388 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) == 0) { 389 /* 390 * On-the-fly resizing is not supported (yet). We still 391 * need to have "size" listed as "supported", otherwise 392 * trying to update fs that is listed in fstab with size 393 * parameter, say trying to change rw to ro or vice 394 * versa, would cause vfs_filteropt() to bail. 395 */ 396 if (size_max != VFS_TO_TMPFS(mp)->tm_size_max) 397 return (EOPNOTSUPP); 398 } 399 if (vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && 400 !(VFS_TO_TMPFS(mp)->tm_ronly)) { 401 /* RW -> RO */ 402 return (tmpfs_rw_to_ro(mp)); 403 } else if (!vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0) && 404 VFS_TO_TMPFS(mp)->tm_ronly) { 405 /* RO -> RW */ 406 VFS_TO_TMPFS(mp)->tm_ronly = 0; 407 MNT_ILOCK(mp); 408 mp->mnt_flag &= ~MNT_RDONLY; 409 MNT_IUNLOCK(mp); 410 } 411 return (0); 412 } 413 414 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY); 415 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred); 416 VOP_UNLOCK(mp->mnt_vnodecovered, 0); 417 if (error) 418 return (error); 419 420 if (mp->mnt_cred->cr_ruid != 0 || 421 vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1) 422 root_gid = va.va_gid; 423 if (mp->mnt_cred->cr_ruid != 0 || 424 vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1) 425 root_uid = va.va_uid; 426 if (mp->mnt_cred->cr_ruid != 0 || 427 vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1) 428 root_mode = va.va_mode; 429 if (vfs_getopt_size(mp->mnt_optnew, "inodes", &nodes_max) != 0) 430 nodes_max = 0; 431 if (vfs_getopt_size(mp->mnt_optnew, "size", &size_max) != 0) 432 size_max = 0; 433 if (vfs_getopt_size(mp->mnt_optnew, "maxfilesize", &maxfilesize) != 0) 434 maxfilesize = 0; 435 nonc = vfs_getopt(mp->mnt_optnew, "nonc", NULL, NULL) == 0; 436 437 /* Do not allow mounts if we do not have enough memory to preserve 438 * the minimum reserved pages. */ 439 if (tmpfs_mem_avail() < TMPFS_PAGES_MINRESERVED) 440 return (ENOSPC); 441 442 /* Get the maximum number of memory pages this file system is 443 * allowed to use, based on the maximum size the user passed in 444 * the mount structure. A value of zero is treated as if the 445 * maximum available space was requested. */ 446 if (size_max == 0 || size_max > OFF_MAX - PAGE_SIZE || 447 (SIZE_MAX < OFF_MAX && size_max / PAGE_SIZE >= SIZE_MAX)) 448 pages = SIZE_MAX; 449 else { 450 size_max = roundup(size_max, PAGE_SIZE); 451 pages = howmany(size_max, PAGE_SIZE); 452 } 453 MPASS(pages > 0); 454 455 if (nodes_max <= 3) { 456 if (pages < INT_MAX / nodes_per_page) 457 nodes_max = pages * nodes_per_page; 458 else 459 nodes_max = INT_MAX; 460 } 461 if (nodes_max > INT_MAX) 462 nodes_max = INT_MAX; 463 MPASS(nodes_max >= 3); 464 465 /* Allocate the tmpfs mount structure and fill it. */ 466 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount), 467 M_TMPFSMNT, M_WAITOK | M_ZERO); 468 469 mtx_init(&tmp->tm_allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF); 470 tmp->tm_nodes_max = nodes_max; 471 tmp->tm_nodes_inuse = 0; 472 tmp->tm_refcount = 1; 473 tmp->tm_maxfilesize = maxfilesize > 0 ? maxfilesize : OFF_MAX; 474 LIST_INIT(&tmp->tm_nodes_used); 475 476 tmp->tm_size_max = size_max; 477 tmp->tm_pages_max = pages; 478 tmp->tm_pages_used = 0; 479 tmp->tm_ino_unr = new_unrhdr(2, INT_MAX, &tmp->tm_allnode_lock); 480 tmp->tm_dirent_pool = uma_zcreate("TMPFS dirent", 481 sizeof(struct tmpfs_dirent), NULL, NULL, NULL, NULL, 482 UMA_ALIGN_PTR, 0); 483 tmp->tm_node_pool = uma_zcreate("TMPFS node", 484 sizeof(struct tmpfs_node), tmpfs_node_ctor, tmpfs_node_dtor, 485 tmpfs_node_init, tmpfs_node_fini, UMA_ALIGN_PTR, 0); 486 tmp->tm_ronly = (mp->mnt_flag & MNT_RDONLY) != 0; 487 tmp->tm_nonc = nonc; 488 489 /* Allocate the root node. */ 490 error = tmpfs_alloc_node(mp, tmp, VDIR, root_uid, root_gid, 491 root_mode & ALLPERMS, NULL, NULL, VNOVAL, &root); 492 493 if (error != 0 || root == NULL) { 494 uma_zdestroy(tmp->tm_node_pool); 495 uma_zdestroy(tmp->tm_dirent_pool); 496 delete_unrhdr(tmp->tm_ino_unr); 497 free(tmp, M_TMPFSMNT); 498 return (error); 499 } 500 KASSERT(root->tn_id == 2, 501 ("tmpfs root with invalid ino: %ju", (uintmax_t)root->tn_id)); 502 tmp->tm_root = root; 503 504 MNT_ILOCK(mp); 505 mp->mnt_flag |= MNT_LOCAL; 506 mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED; 507 MNT_IUNLOCK(mp); 508 509 mp->mnt_data = tmp; 510 mp->mnt_stat.f_namemax = MAXNAMLEN; 511 vfs_getnewfsid(mp); 512 vfs_mountedfrom(mp, "tmpfs"); 513 514 return 0; 515 } 516 517 /* ARGSUSED2 */ 518 static int 519 tmpfs_unmount(struct mount *mp, int mntflags) 520 { 521 struct tmpfs_mount *tmp; 522 struct tmpfs_node *node; 523 int error, flags; 524 525 flags = (mntflags & MNT_FORCE) != 0 ? FORCECLOSE : 0; 526 tmp = VFS_TO_TMPFS(mp); 527 528 /* Stop writers */ 529 error = vfs_write_suspend_umnt(mp); 530 if (error != 0) 531 return (error); 532 /* 533 * At this point, nodes cannot be destroyed by any other 534 * thread because write suspension is started. 535 */ 536 537 for (;;) { 538 error = vflush(mp, 0, flags, curthread); 539 if (error != 0) { 540 vfs_write_resume(mp, VR_START_WRITE); 541 return (error); 542 } 543 MNT_ILOCK(mp); 544 if (mp->mnt_nvnodelistsize == 0) { 545 MNT_IUNLOCK(mp); 546 break; 547 } 548 MNT_IUNLOCK(mp); 549 if ((mntflags & MNT_FORCE) == 0) { 550 vfs_write_resume(mp, VR_START_WRITE); 551 return (EBUSY); 552 } 553 } 554 555 TMPFS_LOCK(tmp); 556 while ((node = LIST_FIRST(&tmp->tm_nodes_used)) != NULL) { 557 TMPFS_NODE_LOCK(node); 558 if (node->tn_type == VDIR) 559 tmpfs_dir_destroy(tmp, node); 560 if (tmpfs_free_node_locked(tmp, node, true)) 561 TMPFS_LOCK(tmp); 562 else 563 TMPFS_NODE_UNLOCK(node); 564 } 565 566 mp->mnt_data = NULL; 567 tmpfs_free_tmp(tmp); 568 vfs_write_resume(mp, VR_START_WRITE); 569 570 MNT_ILOCK(mp); 571 mp->mnt_flag &= ~MNT_LOCAL; 572 MNT_IUNLOCK(mp); 573 574 return (0); 575 } 576 577 void 578 tmpfs_free_tmp(struct tmpfs_mount *tmp) 579 { 580 581 MPASS(tmp->tm_refcount > 0); 582 tmp->tm_refcount--; 583 if (tmp->tm_refcount > 0) { 584 TMPFS_UNLOCK(tmp); 585 return; 586 } 587 TMPFS_UNLOCK(tmp); 588 589 uma_zdestroy(tmp->tm_dirent_pool); 590 uma_zdestroy(tmp->tm_node_pool); 591 delete_unrhdr(tmp->tm_ino_unr); 592 593 mtx_destroy(&tmp->tm_allnode_lock); 594 MPASS(tmp->tm_pages_used == 0); 595 MPASS(tmp->tm_nodes_inuse == 0); 596 597 free(tmp, M_TMPFSMNT); 598 } 599 600 static int 601 tmpfs_root(struct mount *mp, int flags, struct vnode **vpp) 602 { 603 int error; 604 605 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp); 606 if (error == 0) 607 (*vpp)->v_vflag |= VV_ROOT; 608 return (error); 609 } 610 611 static int 612 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags, 613 struct vnode **vpp) 614 { 615 struct tmpfs_fid *tfhp; 616 struct tmpfs_mount *tmp; 617 struct tmpfs_node *node; 618 int error; 619 620 tmp = VFS_TO_TMPFS(mp); 621 622 tfhp = (struct tmpfs_fid *)fhp; 623 if (tfhp->tf_len != sizeof(struct tmpfs_fid)) 624 return (EINVAL); 625 626 if (tfhp->tf_id >= tmp->tm_nodes_max) 627 return (EINVAL); 628 629 TMPFS_LOCK(tmp); 630 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) { 631 if (node->tn_id == tfhp->tf_id && 632 node->tn_gen == tfhp->tf_gen) { 633 tmpfs_ref_node(node); 634 break; 635 } 636 } 637 TMPFS_UNLOCK(tmp); 638 639 if (node != NULL) { 640 error = tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp); 641 tmpfs_free_node(tmp, node); 642 } else 643 error = EINVAL; 644 return (error); 645 } 646 647 /* ARGSUSED2 */ 648 static int 649 tmpfs_statfs(struct mount *mp, struct statfs *sbp) 650 { 651 struct tmpfs_mount *tmp; 652 size_t used; 653 654 tmp = VFS_TO_TMPFS(mp); 655 656 sbp->f_iosize = PAGE_SIZE; 657 sbp->f_bsize = PAGE_SIZE; 658 659 used = tmpfs_pages_used(tmp); 660 if (tmp->tm_pages_max != ULONG_MAX) 661 sbp->f_blocks = tmp->tm_pages_max; 662 else 663 sbp->f_blocks = used + tmpfs_mem_avail(); 664 if (sbp->f_blocks <= used) 665 sbp->f_bavail = 0; 666 else 667 sbp->f_bavail = sbp->f_blocks - used; 668 sbp->f_bfree = sbp->f_bavail; 669 used = tmp->tm_nodes_inuse; 670 sbp->f_files = tmp->tm_nodes_max; 671 if (sbp->f_files <= used) 672 sbp->f_ffree = 0; 673 else 674 sbp->f_ffree = sbp->f_files - used; 675 /* sbp->f_owner = tmp->tn_uid; */ 676 677 return 0; 678 } 679 680 static int 681 tmpfs_sync(struct mount *mp, int waitfor) 682 { 683 684 if (waitfor == MNT_SUSPEND) { 685 MNT_ILOCK(mp); 686 mp->mnt_kern_flag |= MNTK_SUSPEND2 | MNTK_SUSPENDED; 687 MNT_IUNLOCK(mp); 688 } else if (waitfor == MNT_LAZY) { 689 tmpfs_update_mtime(mp, true); 690 } 691 return (0); 692 } 693 694 /* 695 * The presence of a susp_clean method tells the VFS to track writes. 696 */ 697 static void 698 tmpfs_susp_clean(struct mount *mp __unused) 699 { 700 } 701 702 /* 703 * tmpfs vfs operations. 704 */ 705 706 struct vfsops tmpfs_vfsops = { 707 .vfs_mount = tmpfs_mount, 708 .vfs_unmount = tmpfs_unmount, 709 .vfs_root = tmpfs_root, 710 .vfs_statfs = tmpfs_statfs, 711 .vfs_fhtovp = tmpfs_fhtovp, 712 .vfs_sync = tmpfs_sync, 713 .vfs_susp_clean = tmpfs_susp_clean, 714 }; 715 VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);
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