Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/fs/tmpfs/tmpfs_subr.c
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1 /* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad 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 supporting functions. 35 */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include <sys/param.h> 40 #include <sys/namei.h> 41 #include <sys/priv.h> 42 #include <sys/proc.h> 43 #include <sys/stat.h> 44 #include <sys/systm.h> 45 #include <sys/sysctl.h> 46 #include <sys/vnode.h> 47 #include <sys/vmmeter.h> 48 49 #include <vm/vm.h> 50 #include <vm/vm_param.h> 51 #include <vm/vm_object.h> 52 #include <vm/vm_page.h> 53 #include <vm/vm_pageout.h> 54 #include <vm/vm_pager.h> 55 #include <vm/vm_extern.h> 56 57 #include <fs/tmpfs/tmpfs.h> 58 #include <fs/tmpfs/tmpfs_fifoops.h> 59 #include <fs/tmpfs/tmpfs_vnops.h> 60 61 SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW, 0, "tmpfs file system"); 62 63 static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED; 64 65 static int 66 sysctl_mem_reserved(SYSCTL_HANDLER_ARGS) 67 { 68 int error; 69 long pages, bytes; 70 71 pages = *(long *)arg1; 72 bytes = pages * PAGE_SIZE; 73 74 error = sysctl_handle_long(oidp, &bytes, 0, req); 75 if (error || !req->newptr) 76 return (error); 77 78 pages = bytes / PAGE_SIZE; 79 if (pages < TMPFS_PAGES_MINRESERVED) 80 return (EINVAL); 81 82 *(long *)arg1 = pages; 83 return (0); 84 } 85 86 SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_RW, 87 &tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L", 88 "Amount of available memory and swap below which tmpfs growth stops"); 89 90 size_t 91 tmpfs_mem_avail(void) 92 { 93 vm_ooffset_t avail; 94 95 avail = swap_pager_avail + cnt.v_free_count + cnt.v_cache_count - 96 tmpfs_pages_reserved; 97 if (__predict_false(avail < 0)) 98 avail = 0; 99 return (avail); 100 } 101 102 size_t 103 tmpfs_pages_used(struct tmpfs_mount *tmp) 104 { 105 const size_t node_size = sizeof(struct tmpfs_node) + 106 sizeof(struct tmpfs_dirent); 107 size_t meta_pages; 108 109 meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size, 110 PAGE_SIZE); 111 return (meta_pages + tmp->tm_pages_used); 112 } 113 114 static size_t 115 tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages) 116 { 117 if (tmpfs_mem_avail() < req_pages) 118 return (0); 119 120 if (tmp->tm_pages_max != SIZE_MAX && 121 tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp)) 122 return (0); 123 124 return (1); 125 } 126 127 /* --------------------------------------------------------------------- */ 128 129 /* 130 * Allocates a new node of type 'type' inside the 'tmp' mount point, with 131 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', 132 * using the credentials of the process 'p'. 133 * 134 * If the node type is set to 'VDIR', then the parent parameter must point 135 * to the parent directory of the node being created. It may only be NULL 136 * while allocating the root node. 137 * 138 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter 139 * specifies the device the node represents. 140 * 141 * If the node type is set to 'VLNK', then the parameter target specifies 142 * the file name of the target file for the symbolic link that is being 143 * created. 144 * 145 * Note that new nodes are retrieved from the available list if it has 146 * items or, if it is empty, from the node pool as long as there is enough 147 * space to create them. 148 * 149 * Returns zero on success or an appropriate error code on failure. 150 */ 151 int 152 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type, 153 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, 154 char *target, dev_t rdev, struct tmpfs_node **node) 155 { 156 struct tmpfs_node *nnode; 157 158 /* If the root directory of the 'tmp' file system is not yet 159 * allocated, this must be the request to do it. */ 160 MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); 161 162 MPASS(IFF(type == VLNK, target != NULL)); 163 MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL)); 164 165 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) 166 return (ENOSPC); 167 if (tmpfs_pages_check_avail(tmp, 1) == 0) 168 return (ENOSPC); 169 170 nnode = (struct tmpfs_node *)uma_zalloc_arg( 171 tmp->tm_node_pool, tmp, M_WAITOK); 172 173 /* Generic initialization. */ 174 nnode->tn_type = type; 175 vfs_timestamp(&nnode->tn_atime); 176 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = 177 nnode->tn_atime; 178 nnode->tn_uid = uid; 179 nnode->tn_gid = gid; 180 nnode->tn_mode = mode; 181 nnode->tn_id = alloc_unr(tmp->tm_ino_unr); 182 183 /* Type-specific initialization. */ 184 switch (nnode->tn_type) { 185 case VBLK: 186 case VCHR: 187 nnode->tn_rdev = rdev; 188 break; 189 190 case VDIR: 191 TAILQ_INIT(&nnode->tn_dir.tn_dirhead); 192 MPASS(parent != nnode); 193 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL)); 194 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent; 195 nnode->tn_dir.tn_readdir_lastn = 0; 196 nnode->tn_dir.tn_readdir_lastp = NULL; 197 nnode->tn_links++; 198 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent); 199 nnode->tn_dir.tn_parent->tn_links++; 200 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent); 201 break; 202 203 case VFIFO: 204 /* FALLTHROUGH */ 205 case VSOCK: 206 break; 207 208 case VLNK: 209 MPASS(strlen(target) < MAXPATHLEN); 210 nnode->tn_size = strlen(target); 211 nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME, 212 M_WAITOK); 213 memcpy(nnode->tn_link, target, nnode->tn_size); 214 break; 215 216 case VREG: 217 nnode->tn_reg.tn_aobj = 218 vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0, 219 NULL /* XXXKIB - tmpfs needs swap reservation */); 220 break; 221 222 default: 223 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); 224 } 225 226 TMPFS_LOCK(tmp); 227 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); 228 tmp->tm_nodes_inuse++; 229 TMPFS_UNLOCK(tmp); 230 231 *node = nnode; 232 return 0; 233 } 234 235 /* --------------------------------------------------------------------- */ 236 237 /* 238 * Destroys the node pointed to by node from the file system 'tmp'. 239 * If the node does not belong to the given mount point, the results are 240 * unpredicted. 241 * 242 * If the node references a directory; no entries are allowed because 243 * their removal could need a recursive algorithm, something forbidden in 244 * kernel space. Furthermore, there is not need to provide such 245 * functionality (recursive removal) because the only primitives offered 246 * to the user are the removal of empty directories and the deletion of 247 * individual files. 248 * 249 * Note that nodes are not really deleted; in fact, when a node has been 250 * allocated, it cannot be deleted during the whole life of the file 251 * system. Instead, they are moved to the available list and remain there 252 * until reused. 253 */ 254 void 255 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) 256 { 257 vm_object_t uobj; 258 259 #ifdef INVARIANTS 260 TMPFS_NODE_LOCK(node); 261 MPASS(node->tn_vnode == NULL); 262 MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0); 263 TMPFS_NODE_UNLOCK(node); 264 #endif 265 266 TMPFS_LOCK(tmp); 267 LIST_REMOVE(node, tn_entries); 268 tmp->tm_nodes_inuse--; 269 TMPFS_UNLOCK(tmp); 270 271 switch (node->tn_type) { 272 case VNON: 273 /* Do not do anything. VNON is provided to let the 274 * allocation routine clean itself easily by avoiding 275 * duplicating code in it. */ 276 /* FALLTHROUGH */ 277 case VBLK: 278 /* FALLTHROUGH */ 279 case VCHR: 280 /* FALLTHROUGH */ 281 case VDIR: 282 /* FALLTHROUGH */ 283 case VFIFO: 284 /* FALLTHROUGH */ 285 case VSOCK: 286 break; 287 288 case VLNK: 289 free(node->tn_link, M_TMPFSNAME); 290 break; 291 292 case VREG: 293 uobj = node->tn_reg.tn_aobj; 294 if (uobj != NULL) { 295 TMPFS_LOCK(tmp); 296 tmp->tm_pages_used -= uobj->size; 297 TMPFS_UNLOCK(tmp); 298 vm_object_deallocate(uobj); 299 } 300 break; 301 302 default: 303 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); 304 } 305 306 free_unr(tmp->tm_ino_unr, node->tn_id); 307 uma_zfree(tmp->tm_node_pool, node); 308 } 309 310 /* --------------------------------------------------------------------- */ 311 312 /* 313 * Allocates a new directory entry for the node node with a name of name. 314 * The new directory entry is returned in *de. 315 * 316 * The link count of node is increased by one to reflect the new object 317 * referencing it. 318 * 319 * Returns zero on success or an appropriate error code on failure. 320 */ 321 int 322 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 323 const char *name, uint16_t len, struct tmpfs_dirent **de) 324 { 325 struct tmpfs_dirent *nde; 326 327 nde = (struct tmpfs_dirent *)uma_zalloc( 328 tmp->tm_dirent_pool, M_WAITOK); 329 nde->td_name = malloc(len, M_TMPFSNAME, M_WAITOK); 330 nde->td_namelen = len; 331 memcpy(nde->td_name, name, len); 332 333 nde->td_node = node; 334 if (node != NULL) 335 node->tn_links++; 336 337 *de = nde; 338 339 return 0; 340 } 341 342 /* --------------------------------------------------------------------- */ 343 344 /* 345 * Frees a directory entry. It is the caller's responsibility to destroy 346 * the node referenced by it if needed. 347 * 348 * The link count of node is decreased by one to reflect the removal of an 349 * object that referenced it. This only happens if 'node_exists' is true; 350 * otherwise the function will not access the node referred to by the 351 * directory entry, as it may already have been released from the outside. 352 */ 353 void 354 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de, 355 boolean_t node_exists) 356 { 357 if (node_exists) { 358 struct tmpfs_node *node; 359 360 node = de->td_node; 361 if (node != NULL) { 362 MPASS(node->tn_links > 0); 363 node->tn_links--; 364 } 365 } 366 367 free(de->td_name, M_TMPFSNAME); 368 uma_zfree(tmp->tm_dirent_pool, de); 369 } 370 371 /* --------------------------------------------------------------------- */ 372 373 /* 374 * Allocates a new vnode for the node node or returns a new reference to 375 * an existing one if the node had already a vnode referencing it. The 376 * resulting locked vnode is returned in *vpp. 377 * 378 * Returns zero on success or an appropriate error code on failure. 379 */ 380 int 381 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag, 382 struct vnode **vpp) 383 { 384 int error = 0; 385 struct vnode *vp; 386 387 loop: 388 TMPFS_NODE_LOCK(node); 389 loop1: 390 if ((vp = node->tn_vnode) != NULL) { 391 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); 392 VI_LOCK(vp); 393 if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) || 394 ((vp->v_iflag & VI_DOOMED) != 0 && 395 (lkflag & LK_NOWAIT) != 0)) { 396 VI_UNLOCK(vp); 397 TMPFS_NODE_UNLOCK(node); 398 error = ENOENT; 399 vp = NULL; 400 goto out; 401 } 402 if ((vp->v_iflag & VI_DOOMED) != 0) { 403 VI_UNLOCK(vp); 404 node->tn_vpstate |= TMPFS_VNODE_WRECLAIM; 405 while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) { 406 msleep(&node->tn_vnode, TMPFS_NODE_MTX(node), 407 0, "tmpfsE", 0); 408 } 409 goto loop1; 410 } 411 TMPFS_NODE_UNLOCK(node); 412 error = vget(vp, lkflag | LK_INTERLOCK, curthread); 413 if (error == ENOENT) 414 goto loop; 415 if (error != 0) { 416 vp = NULL; 417 goto out; 418 } 419 420 /* 421 * Make sure the vnode is still there after 422 * getting the interlock to avoid racing a free. 423 */ 424 if (node->tn_vnode == NULL || node->tn_vnode != vp) { 425 vput(vp); 426 goto loop; 427 } 428 429 goto out; 430 } 431 432 if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) || 433 (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) { 434 TMPFS_NODE_UNLOCK(node); 435 error = ENOENT; 436 vp = NULL; 437 goto out; 438 } 439 440 /* 441 * otherwise lock the vp list while we call getnewvnode 442 * since that can block. 443 */ 444 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) { 445 node->tn_vpstate |= TMPFS_VNODE_WANT; 446 error = msleep((caddr_t) &node->tn_vpstate, 447 TMPFS_NODE_MTX(node), PDROP | PCATCH, 448 "tmpfs_alloc_vp", 0); 449 if (error) 450 return error; 451 452 goto loop; 453 } else 454 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING; 455 456 TMPFS_NODE_UNLOCK(node); 457 458 /* Get a new vnode and associate it with our node. */ 459 error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp); 460 if (error != 0) 461 goto unlock; 462 MPASS(vp != NULL); 463 464 (void) vn_lock(vp, lkflag | LK_RETRY); 465 466 vp->v_data = node; 467 vp->v_type = node->tn_type; 468 469 /* Type-specific initialization. */ 470 switch (node->tn_type) { 471 case VBLK: 472 /* FALLTHROUGH */ 473 case VCHR: 474 /* FALLTHROUGH */ 475 case VLNK: 476 /* FALLTHROUGH */ 477 case VREG: 478 /* FALLTHROUGH */ 479 case VSOCK: 480 break; 481 case VFIFO: 482 vp->v_op = &tmpfs_fifoop_entries; 483 break; 484 case VDIR: 485 MPASS(node->tn_dir.tn_parent != NULL); 486 if (node->tn_dir.tn_parent == node) 487 vp->v_vflag |= VV_ROOT; 488 break; 489 490 default: 491 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); 492 } 493 494 vnode_pager_setsize(vp, node->tn_size); 495 error = insmntque(vp, mp); 496 if (error) 497 vp = NULL; 498 499 unlock: 500 TMPFS_NODE_LOCK(node); 501 502 MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING); 503 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING; 504 node->tn_vnode = vp; 505 506 if (node->tn_vpstate & TMPFS_VNODE_WANT) { 507 node->tn_vpstate &= ~TMPFS_VNODE_WANT; 508 TMPFS_NODE_UNLOCK(node); 509 wakeup((caddr_t) &node->tn_vpstate); 510 } else 511 TMPFS_NODE_UNLOCK(node); 512 513 out: 514 *vpp = vp; 515 516 #ifdef INVARIANTS 517 if (error == 0) { 518 MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp)); 519 TMPFS_NODE_LOCK(node); 520 MPASS(*vpp == node->tn_vnode); 521 TMPFS_NODE_UNLOCK(node); 522 } 523 #endif 524 525 return error; 526 } 527 528 /* --------------------------------------------------------------------- */ 529 530 /* 531 * Destroys the association between the vnode vp and the node it 532 * references. 533 */ 534 void 535 tmpfs_free_vp(struct vnode *vp) 536 { 537 struct tmpfs_node *node; 538 539 node = VP_TO_TMPFS_NODE(vp); 540 541 mtx_assert(TMPFS_NODE_MTX(node), MA_OWNED); 542 node->tn_vnode = NULL; 543 if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) 544 wakeup(&node->tn_vnode); 545 node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM; 546 vp->v_data = NULL; 547 } 548 549 /* --------------------------------------------------------------------- */ 550 551 /* 552 * Allocates a new file of type 'type' and adds it to the parent directory 553 * 'dvp'; this addition is done using the component name given in 'cnp'. 554 * The ownership of the new file is automatically assigned based on the 555 * credentials of the caller (through 'cnp'), the group is set based on 556 * the parent directory and the mode is determined from the 'vap' argument. 557 * If successful, *vpp holds a vnode to the newly created file and zero 558 * is returned. Otherwise *vpp is NULL and the function returns an 559 * appropriate error code. 560 */ 561 int 562 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 563 struct componentname *cnp, char *target) 564 { 565 int error; 566 struct tmpfs_dirent *de; 567 struct tmpfs_mount *tmp; 568 struct tmpfs_node *dnode; 569 struct tmpfs_node *node; 570 struct tmpfs_node *parent; 571 572 MPASS(VOP_ISLOCKED(dvp)); 573 MPASS(cnp->cn_flags & HASBUF); 574 575 tmp = VFS_TO_TMPFS(dvp->v_mount); 576 dnode = VP_TO_TMPFS_DIR(dvp); 577 *vpp = NULL; 578 579 /* If the entry we are creating is a directory, we cannot overflow 580 * the number of links of its parent, because it will get a new 581 * link. */ 582 if (vap->va_type == VDIR) { 583 /* Ensure that we do not overflow the maximum number of links 584 * imposed by the system. */ 585 MPASS(dnode->tn_links <= LINK_MAX); 586 if (dnode->tn_links == LINK_MAX) { 587 error = EMLINK; 588 goto out; 589 } 590 591 parent = dnode; 592 MPASS(parent != NULL); 593 } else 594 parent = NULL; 595 596 /* Allocate a node that represents the new file. */ 597 error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid, 598 dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node); 599 if (error != 0) 600 goto out; 601 602 /* Allocate a directory entry that points to the new file. */ 603 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, 604 &de); 605 if (error != 0) { 606 tmpfs_free_node(tmp, node); 607 goto out; 608 } 609 610 /* Allocate a vnode for the new file. */ 611 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp); 612 if (error != 0) { 613 tmpfs_free_dirent(tmp, de, TRUE); 614 tmpfs_free_node(tmp, node); 615 goto out; 616 } 617 618 /* Now that all required items are allocated, we can proceed to 619 * insert the new node into the directory, an operation that 620 * cannot fail. */ 621 if (cnp->cn_flags & ISWHITEOUT) 622 tmpfs_dir_whiteout_remove(dvp, cnp); 623 tmpfs_dir_attach(dvp, de); 624 625 out: 626 627 return error; 628 } 629 630 /* --------------------------------------------------------------------- */ 631 632 /* 633 * Attaches the directory entry de to the directory represented by vp. 634 * Note that this does not change the link count of the node pointed by 635 * the directory entry, as this is done by tmpfs_alloc_dirent. 636 */ 637 void 638 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) 639 { 640 struct tmpfs_node *dnode; 641 642 ASSERT_VOP_ELOCKED(vp, __func__); 643 dnode = VP_TO_TMPFS_DIR(vp); 644 TAILQ_INSERT_TAIL(&dnode->tn_dir.tn_dirhead, de, td_entries); 645 dnode->tn_size += sizeof(struct tmpfs_dirent); 646 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 647 TMPFS_NODE_MODIFIED; 648 } 649 650 /* --------------------------------------------------------------------- */ 651 652 /* 653 * Detaches the directory entry de from the directory represented by vp. 654 * Note that this does not change the link count of the node pointed by 655 * the directory entry, as this is done by tmpfs_free_dirent. 656 */ 657 void 658 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) 659 { 660 struct tmpfs_node *dnode; 661 662 ASSERT_VOP_ELOCKED(vp, __func__); 663 dnode = VP_TO_TMPFS_DIR(vp); 664 665 if (dnode->tn_dir.tn_readdir_lastp == de) { 666 dnode->tn_dir.tn_readdir_lastn = 0; 667 dnode->tn_dir.tn_readdir_lastp = NULL; 668 } 669 670 TAILQ_REMOVE(&dnode->tn_dir.tn_dirhead, de, td_entries); 671 dnode->tn_size -= sizeof(struct tmpfs_dirent); 672 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 673 TMPFS_NODE_MODIFIED; 674 } 675 676 /* --------------------------------------------------------------------- */ 677 678 /* 679 * Looks for a directory entry in the directory represented by node. 680 * 'cnp' describes the name of the entry to look for. Note that the . 681 * and .. components are not allowed as they do not physically exist 682 * within directories. 683 * 684 * Returns a pointer to the entry when found, otherwise NULL. 685 */ 686 struct tmpfs_dirent * 687 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, 688 struct componentname *cnp) 689 { 690 boolean_t found; 691 struct tmpfs_dirent *de; 692 693 MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); 694 MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && 695 cnp->cn_nameptr[1] == '.'))); 696 TMPFS_VALIDATE_DIR(node); 697 698 found = 0; 699 TAILQ_FOREACH(de, &node->tn_dir.tn_dirhead, td_entries) { 700 if (f != NULL && de->td_node != f) 701 continue; 702 MPASS(cnp->cn_namelen < 0xffff); 703 if (de->td_namelen == (uint16_t)cnp->cn_namelen && 704 bcmp(de->td_name, cnp->cn_nameptr, de->td_namelen) == 0) { 705 found = 1; 706 break; 707 } 708 } 709 node->tn_status |= TMPFS_NODE_ACCESSED; 710 711 return found ? de : NULL; 712 } 713 714 /* --------------------------------------------------------------------- */ 715 716 /* 717 * Helper function for tmpfs_readdir. Creates a '.' entry for the given 718 * directory and returns it in the uio space. The function returns 0 719 * on success, -1 if there was not enough space in the uio structure to 720 * hold the directory entry or an appropriate error code if another 721 * error happens. 722 */ 723 int 724 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) 725 { 726 int error; 727 struct dirent dent; 728 729 TMPFS_VALIDATE_DIR(node); 730 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); 731 732 dent.d_fileno = node->tn_id; 733 dent.d_type = DT_DIR; 734 dent.d_namlen = 1; 735 dent.d_name[0] = '.'; 736 dent.d_name[1] = '\0'; 737 dent.d_reclen = GENERIC_DIRSIZ(&dent); 738 739 if (dent.d_reclen > uio->uio_resid) 740 error = -1; 741 else { 742 error = uiomove(&dent, dent.d_reclen, uio); 743 if (error == 0) 744 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 745 } 746 747 node->tn_status |= TMPFS_NODE_ACCESSED; 748 749 return error; 750 } 751 752 /* --------------------------------------------------------------------- */ 753 754 /* 755 * Helper function for tmpfs_readdir. Creates a '..' entry for the given 756 * directory and returns it in the uio space. The function returns 0 757 * on success, -1 if there was not enough space in the uio structure to 758 * hold the directory entry or an appropriate error code if another 759 * error happens. 760 */ 761 int 762 tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio) 763 { 764 int error; 765 struct dirent dent; 766 767 TMPFS_VALIDATE_DIR(node); 768 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); 769 770 /* 771 * Return ENOENT if the current node is already removed. 772 */ 773 TMPFS_ASSERT_LOCKED(node); 774 if (node->tn_dir.tn_parent == NULL) { 775 return (ENOENT); 776 } 777 778 TMPFS_NODE_LOCK(node->tn_dir.tn_parent); 779 dent.d_fileno = node->tn_dir.tn_parent->tn_id; 780 TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent); 781 782 dent.d_type = DT_DIR; 783 dent.d_namlen = 2; 784 dent.d_name[0] = '.'; 785 dent.d_name[1] = '.'; 786 dent.d_name[2] = '\0'; 787 dent.d_reclen = GENERIC_DIRSIZ(&dent); 788 789 if (dent.d_reclen > uio->uio_resid) 790 error = -1; 791 else { 792 error = uiomove(&dent, dent.d_reclen, uio); 793 if (error == 0) { 794 struct tmpfs_dirent *de; 795 796 de = TAILQ_FIRST(&node->tn_dir.tn_dirhead); 797 if (de == NULL) 798 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 799 else 800 uio->uio_offset = tmpfs_dircookie(de); 801 } 802 } 803 804 node->tn_status |= TMPFS_NODE_ACCESSED; 805 806 return error; 807 } 808 809 /* --------------------------------------------------------------------- */ 810 811 /* 812 * Lookup a directory entry by its associated cookie. 813 */ 814 struct tmpfs_dirent * 815 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie) 816 { 817 struct tmpfs_dirent *de; 818 819 if (cookie == node->tn_dir.tn_readdir_lastn && 820 node->tn_dir.tn_readdir_lastp != NULL) { 821 return node->tn_dir.tn_readdir_lastp; 822 } 823 824 TAILQ_FOREACH(de, &node->tn_dir.tn_dirhead, td_entries) { 825 if (tmpfs_dircookie(de) == cookie) { 826 break; 827 } 828 } 829 830 return de; 831 } 832 833 /* --------------------------------------------------------------------- */ 834 835 /* 836 * Helper function for tmpfs_readdir. Returns as much directory entries 837 * as can fit in the uio space. The read starts at uio->uio_offset. 838 * The function returns 0 on success, -1 if there was not enough space 839 * in the uio structure to hold the directory entry or an appropriate 840 * error code if another error happens. 841 */ 842 int 843 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp) 844 { 845 int error; 846 off_t startcookie; 847 struct tmpfs_dirent *de; 848 849 TMPFS_VALIDATE_DIR(node); 850 851 /* Locate the first directory entry we have to return. We have cached 852 * the last readdir in the node, so use those values if appropriate. 853 * Otherwise do a linear scan to find the requested entry. */ 854 startcookie = uio->uio_offset; 855 MPASS(startcookie != TMPFS_DIRCOOKIE_DOT); 856 MPASS(startcookie != TMPFS_DIRCOOKIE_DOTDOT); 857 if (startcookie == TMPFS_DIRCOOKIE_EOF) { 858 return 0; 859 } else { 860 de = tmpfs_dir_lookupbycookie(node, startcookie); 861 } 862 if (de == NULL) { 863 return EINVAL; 864 } 865 866 /* Read as much entries as possible; i.e., until we reach the end of 867 * the directory or we exhaust uio space. */ 868 do { 869 struct dirent d; 870 871 /* Create a dirent structure representing the current 872 * tmpfs_node and fill it. */ 873 if (de->td_node == NULL) { 874 d.d_fileno = 1; 875 d.d_type = DT_WHT; 876 } else { 877 d.d_fileno = de->td_node->tn_id; 878 switch (de->td_node->tn_type) { 879 case VBLK: 880 d.d_type = DT_BLK; 881 break; 882 883 case VCHR: 884 d.d_type = DT_CHR; 885 break; 886 887 case VDIR: 888 d.d_type = DT_DIR; 889 break; 890 891 case VFIFO: 892 d.d_type = DT_FIFO; 893 break; 894 895 case VLNK: 896 d.d_type = DT_LNK; 897 break; 898 899 case VREG: 900 d.d_type = DT_REG; 901 break; 902 903 case VSOCK: 904 d.d_type = DT_SOCK; 905 break; 906 907 default: 908 panic("tmpfs_dir_getdents: type %p %d", 909 de->td_node, (int)de->td_node->tn_type); 910 } 911 } 912 d.d_namlen = de->td_namelen; 913 MPASS(de->td_namelen < sizeof(d.d_name)); 914 (void)memcpy(d.d_name, de->td_name, de->td_namelen); 915 d.d_name[de->td_namelen] = '\0'; 916 d.d_reclen = GENERIC_DIRSIZ(&d); 917 918 /* Stop reading if the directory entry we are treating is 919 * bigger than the amount of data that can be returned. */ 920 if (d.d_reclen > uio->uio_resid) { 921 error = -1; 922 break; 923 } 924 925 /* Copy the new dirent structure into the output buffer and 926 * advance pointers. */ 927 error = uiomove(&d, d.d_reclen, uio); 928 if (error == 0) { 929 (*cntp)++; 930 de = TAILQ_NEXT(de, td_entries); 931 } 932 } while (error == 0 && uio->uio_resid > 0 && de != NULL); 933 934 /* Update the offset and cache. */ 935 if (de == NULL) { 936 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 937 node->tn_dir.tn_readdir_lastn = 0; 938 node->tn_dir.tn_readdir_lastp = NULL; 939 } else { 940 node->tn_dir.tn_readdir_lastn = uio->uio_offset = tmpfs_dircookie(de); 941 node->tn_dir.tn_readdir_lastp = de; 942 } 943 944 node->tn_status |= TMPFS_NODE_ACCESSED; 945 return error; 946 } 947 948 int 949 tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp) 950 { 951 struct tmpfs_dirent *de; 952 int error; 953 954 error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL, 955 cnp->cn_nameptr, cnp->cn_namelen, &de); 956 if (error != 0) 957 return (error); 958 tmpfs_dir_attach(dvp, de); 959 return (0); 960 } 961 962 void 963 tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) 964 { 965 struct tmpfs_dirent *de; 966 967 de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp); 968 MPASS(de != NULL && de->td_node == NULL); 969 tmpfs_dir_detach(dvp, de); 970 tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de, TRUE); 971 } 972 973 /* --------------------------------------------------------------------- */ 974 975 /* 976 * Resizes the aobj associated with the regular file pointed to by 'vp' to the 977 * size 'newsize'. 'vp' must point to a vnode that represents a regular file. 978 * 'newsize' must be positive. 979 * 980 * Returns zero on success or an appropriate error code on failure. 981 */ 982 int 983 tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) 984 { 985 struct tmpfs_mount *tmp; 986 struct tmpfs_node *node; 987 vm_object_t uobj; 988 vm_page_t m, ma[1]; 989 vm_pindex_t idx, newpages, oldpages; 990 off_t oldsize; 991 int base, rv; 992 993 MPASS(vp->v_type == VREG); 994 MPASS(newsize >= 0); 995 996 node = VP_TO_TMPFS_NODE(vp); 997 uobj = node->tn_reg.tn_aobj; 998 tmp = VFS_TO_TMPFS(vp->v_mount); 999 1000 /* 1001 * Convert the old and new sizes to the number of pages needed to 1002 * store them. It may happen that we do not need to do anything 1003 * because the last allocated page can accommodate the change on 1004 * its own. 1005 */ 1006 oldsize = node->tn_size; 1007 oldpages = OFF_TO_IDX(oldsize + PAGE_MASK); 1008 MPASS(oldpages == uobj->size); 1009 newpages = OFF_TO_IDX(newsize + PAGE_MASK); 1010 if (newpages > oldpages && 1011 tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0) 1012 return (ENOSPC); 1013 1014 VM_OBJECT_LOCK(uobj); 1015 if (newsize < oldsize) { 1016 /* 1017 * Zero the truncated part of the last page. 1018 */ 1019 base = newsize & PAGE_MASK; 1020 if (base != 0) { 1021 idx = OFF_TO_IDX(newsize); 1022 retry: 1023 m = vm_page_lookup(uobj, idx); 1024 if (m != NULL) { 1025 if ((m->oflags & VPO_BUSY) != 0 || 1026 m->busy != 0) { 1027 vm_page_sleep(m, "tmfssz"); 1028 goto retry; 1029 } 1030 MPASS(m->valid == VM_PAGE_BITS_ALL); 1031 } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { 1032 m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL); 1033 if (m == NULL) { 1034 VM_OBJECT_UNLOCK(uobj); 1035 VM_WAIT; 1036 VM_OBJECT_LOCK(uobj); 1037 goto retry; 1038 } else if (m->valid != VM_PAGE_BITS_ALL) { 1039 ma[0] = m; 1040 rv = vm_pager_get_pages(uobj, ma, 1, 0); 1041 m = vm_page_lookup(uobj, idx); 1042 } else 1043 /* A cached page was reactivated. */ 1044 rv = VM_PAGER_OK; 1045 vm_page_lock(m); 1046 if (rv == VM_PAGER_OK) { 1047 vm_page_deactivate(m); 1048 vm_page_unlock(m); 1049 vm_page_wakeup(m); 1050 } else { 1051 vm_page_free(m); 1052 vm_page_unlock(m); 1053 if (ignerr) 1054 m = NULL; 1055 else { 1056 VM_OBJECT_UNLOCK(uobj); 1057 return (EIO); 1058 } 1059 } 1060 } 1061 if (m != NULL) { 1062 pmap_zero_page_area(m, base, PAGE_SIZE - base); 1063 vm_page_dirty(m); 1064 vm_pager_page_unswapped(m); 1065 } 1066 } 1067 1068 /* 1069 * Release any swap space and free any whole pages. 1070 */ 1071 if (newpages < oldpages) { 1072 swap_pager_freespace(uobj, newpages, oldpages - 1073 newpages); 1074 vm_object_page_remove(uobj, newpages, 0, 0); 1075 } 1076 } 1077 uobj->size = newpages; 1078 VM_OBJECT_UNLOCK(uobj); 1079 1080 TMPFS_LOCK(tmp); 1081 tmp->tm_pages_used += (newpages - oldpages); 1082 TMPFS_UNLOCK(tmp); 1083 1084 node->tn_size = newsize; 1085 vnode_pager_setsize(vp, newsize); 1086 return (0); 1087 } 1088 1089 /* --------------------------------------------------------------------- */ 1090 1091 /* 1092 * Change flags of the given vnode. 1093 * Caller should execute tmpfs_update on vp after a successful execution. 1094 * The vnode must be locked on entry and remain locked on exit. 1095 */ 1096 int 1097 tmpfs_chflags(struct vnode *vp, int flags, struct ucred *cred, struct thread *p) 1098 { 1099 int error; 1100 struct tmpfs_node *node; 1101 1102 MPASS(VOP_ISLOCKED(vp)); 1103 1104 node = VP_TO_TMPFS_NODE(vp); 1105 1106 /* Disallow this operation if the file system is mounted read-only. */ 1107 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1108 return EROFS; 1109 1110 /* 1111 * Callers may only modify the file flags on objects they 1112 * have VADMIN rights for. 1113 */ 1114 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1115 return (error); 1116 /* 1117 * Unprivileged processes are not permitted to unset system 1118 * flags, or modify flags if any system flags are set. 1119 */ 1120 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) { 1121 if (node->tn_flags 1122 & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) { 1123 error = securelevel_gt(cred, 0); 1124 if (error) 1125 return (error); 1126 } 1127 /* Snapshot flag cannot be set or cleared */ 1128 if (((flags & SF_SNAPSHOT) != 0 && 1129 (node->tn_flags & SF_SNAPSHOT) == 0) || 1130 ((flags & SF_SNAPSHOT) == 0 && 1131 (node->tn_flags & SF_SNAPSHOT) != 0)) 1132 return (EPERM); 1133 node->tn_flags = flags; 1134 } else { 1135 if (node->tn_flags 1136 & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || 1137 (flags & UF_SETTABLE) != flags) 1138 return (EPERM); 1139 node->tn_flags &= SF_SETTABLE; 1140 node->tn_flags |= (flags & UF_SETTABLE); 1141 } 1142 node->tn_status |= TMPFS_NODE_CHANGED; 1143 1144 MPASS(VOP_ISLOCKED(vp)); 1145 1146 return 0; 1147 } 1148 1149 /* --------------------------------------------------------------------- */ 1150 1151 /* 1152 * Change access mode on the given vnode. 1153 * Caller should execute tmpfs_update on vp after a successful execution. 1154 * The vnode must be locked on entry and remain locked on exit. 1155 */ 1156 int 1157 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p) 1158 { 1159 int error; 1160 struct tmpfs_node *node; 1161 1162 MPASS(VOP_ISLOCKED(vp)); 1163 1164 node = VP_TO_TMPFS_NODE(vp); 1165 1166 /* Disallow this operation if the file system is mounted read-only. */ 1167 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1168 return EROFS; 1169 1170 /* Immutable or append-only files cannot be modified, either. */ 1171 if (node->tn_flags & (IMMUTABLE | APPEND)) 1172 return EPERM; 1173 1174 /* 1175 * To modify the permissions on a file, must possess VADMIN 1176 * for that file. 1177 */ 1178 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1179 return (error); 1180 1181 /* 1182 * Privileged processes may set the sticky bit on non-directories, 1183 * as well as set the setgid bit on a file with a group that the 1184 * process is not a member of. 1185 */ 1186 if (vp->v_type != VDIR && (mode & S_ISTXT)) { 1187 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0)) 1188 return (EFTYPE); 1189 } 1190 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) { 1191 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0); 1192 if (error) 1193 return (error); 1194 } 1195 1196 1197 node->tn_mode &= ~ALLPERMS; 1198 node->tn_mode |= mode & ALLPERMS; 1199 1200 node->tn_status |= TMPFS_NODE_CHANGED; 1201 1202 MPASS(VOP_ISLOCKED(vp)); 1203 1204 return 0; 1205 } 1206 1207 /* --------------------------------------------------------------------- */ 1208 1209 /* 1210 * Change ownership of the given vnode. At least one of uid or gid must 1211 * be different than VNOVAL. If one is set to that value, the attribute 1212 * is unchanged. 1213 * Caller should execute tmpfs_update on vp after a successful execution. 1214 * The vnode must be locked on entry and remain locked on exit. 1215 */ 1216 int 1217 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, 1218 struct thread *p) 1219 { 1220 int error; 1221 struct tmpfs_node *node; 1222 uid_t ouid; 1223 gid_t ogid; 1224 1225 MPASS(VOP_ISLOCKED(vp)); 1226 1227 node = VP_TO_TMPFS_NODE(vp); 1228 1229 /* Assign default values if they are unknown. */ 1230 MPASS(uid != VNOVAL || gid != VNOVAL); 1231 if (uid == VNOVAL) 1232 uid = node->tn_uid; 1233 if (gid == VNOVAL) 1234 gid = node->tn_gid; 1235 MPASS(uid != VNOVAL && gid != VNOVAL); 1236 1237 /* Disallow this operation if the file system is mounted read-only. */ 1238 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1239 return EROFS; 1240 1241 /* Immutable or append-only files cannot be modified, either. */ 1242 if (node->tn_flags & (IMMUTABLE | APPEND)) 1243 return EPERM; 1244 1245 /* 1246 * To modify the ownership of a file, must possess VADMIN for that 1247 * file. 1248 */ 1249 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1250 return (error); 1251 1252 /* 1253 * To change the owner of a file, or change the group of a file to a 1254 * group of which we are not a member, the caller must have 1255 * privilege. 1256 */ 1257 if ((uid != node->tn_uid || 1258 (gid != node->tn_gid && !groupmember(gid, cred))) && 1259 (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0))) 1260 return (error); 1261 1262 ogid = node->tn_gid; 1263 ouid = node->tn_uid; 1264 1265 node->tn_uid = uid; 1266 node->tn_gid = gid; 1267 1268 node->tn_status |= TMPFS_NODE_CHANGED; 1269 1270 if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) { 1271 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0)) 1272 node->tn_mode &= ~(S_ISUID | S_ISGID); 1273 } 1274 1275 MPASS(VOP_ISLOCKED(vp)); 1276 1277 return 0; 1278 } 1279 1280 /* --------------------------------------------------------------------- */ 1281 1282 /* 1283 * Change size of the given vnode. 1284 * Caller should execute tmpfs_update on vp after a successful execution. 1285 * The vnode must be locked on entry and remain locked on exit. 1286 */ 1287 int 1288 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, 1289 struct thread *p) 1290 { 1291 int error; 1292 struct tmpfs_node *node; 1293 1294 MPASS(VOP_ISLOCKED(vp)); 1295 1296 node = VP_TO_TMPFS_NODE(vp); 1297 1298 /* Decide whether this is a valid operation based on the file type. */ 1299 error = 0; 1300 switch (vp->v_type) { 1301 case VDIR: 1302 return EISDIR; 1303 1304 case VREG: 1305 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1306 return EROFS; 1307 break; 1308 1309 case VBLK: 1310 /* FALLTHROUGH */ 1311 case VCHR: 1312 /* FALLTHROUGH */ 1313 case VFIFO: 1314 /* Allow modifications of special files even if in the file 1315 * system is mounted read-only (we are not modifying the 1316 * files themselves, but the objects they represent). */ 1317 return 0; 1318 1319 default: 1320 /* Anything else is unsupported. */ 1321 return EOPNOTSUPP; 1322 } 1323 1324 /* Immutable or append-only files cannot be modified, either. */ 1325 if (node->tn_flags & (IMMUTABLE | APPEND)) 1326 return EPERM; 1327 1328 error = tmpfs_truncate(vp, size); 1329 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents 1330 * for us, as will update tn_status; no need to do that here. */ 1331 1332 MPASS(VOP_ISLOCKED(vp)); 1333 1334 return error; 1335 } 1336 1337 /* --------------------------------------------------------------------- */ 1338 1339 /* 1340 * Change access and modification times of the given vnode. 1341 * Caller should execute tmpfs_update on vp after a successful execution. 1342 * The vnode must be locked on entry and remain locked on exit. 1343 */ 1344 int 1345 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime, 1346 struct timespec *birthtime, int vaflags, struct ucred *cred, struct thread *l) 1347 { 1348 int error; 1349 struct tmpfs_node *node; 1350 1351 MPASS(VOP_ISLOCKED(vp)); 1352 1353 node = VP_TO_TMPFS_NODE(vp); 1354 1355 /* Disallow this operation if the file system is mounted read-only. */ 1356 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1357 return EROFS; 1358 1359 /* Immutable or append-only files cannot be modified, either. */ 1360 if (node->tn_flags & (IMMUTABLE | APPEND)) 1361 return EPERM; 1362 1363 /* Determine if the user have proper privilege to update time. */ 1364 if (vaflags & VA_UTIMES_NULL) { 1365 error = VOP_ACCESS(vp, VADMIN, cred, l); 1366 if (error) 1367 error = VOP_ACCESS(vp, VWRITE, cred, l); 1368 } else 1369 error = VOP_ACCESS(vp, VADMIN, cred, l); 1370 if (error) 1371 return (error); 1372 1373 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL) 1374 node->tn_status |= TMPFS_NODE_ACCESSED; 1375 1376 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) 1377 node->tn_status |= TMPFS_NODE_MODIFIED; 1378 1379 if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL) 1380 node->tn_status |= TMPFS_NODE_MODIFIED; 1381 1382 tmpfs_itimes(vp, atime, mtime); 1383 1384 if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL) 1385 node->tn_birthtime = *birthtime; 1386 MPASS(VOP_ISLOCKED(vp)); 1387 1388 return 0; 1389 } 1390 1391 /* --------------------------------------------------------------------- */ 1392 /* Sync timestamps */ 1393 void 1394 tmpfs_itimes(struct vnode *vp, const struct timespec *acc, 1395 const struct timespec *mod) 1396 { 1397 struct tmpfs_node *node; 1398 struct timespec now; 1399 1400 node = VP_TO_TMPFS_NODE(vp); 1401 1402 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1403 TMPFS_NODE_CHANGED)) == 0) 1404 return; 1405 1406 vfs_timestamp(&now); 1407 if (node->tn_status & TMPFS_NODE_ACCESSED) { 1408 if (acc == NULL) 1409 acc = &now; 1410 node->tn_atime = *acc; 1411 } 1412 if (node->tn_status & TMPFS_NODE_MODIFIED) { 1413 if (mod == NULL) 1414 mod = &now; 1415 node->tn_mtime = *mod; 1416 } 1417 if (node->tn_status & TMPFS_NODE_CHANGED) { 1418 node->tn_ctime = now; 1419 } 1420 node->tn_status &= 1421 ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); 1422 } 1423 1424 /* --------------------------------------------------------------------- */ 1425 1426 void 1427 tmpfs_update(struct vnode *vp) 1428 { 1429 1430 tmpfs_itimes(vp, NULL, NULL); 1431 } 1432 1433 /* --------------------------------------------------------------------- */ 1434 1435 int 1436 tmpfs_truncate(struct vnode *vp, off_t length) 1437 { 1438 int error; 1439 struct tmpfs_node *node; 1440 1441 node = VP_TO_TMPFS_NODE(vp); 1442 1443 if (length < 0) { 1444 error = EINVAL; 1445 goto out; 1446 } 1447 1448 if (node->tn_size == length) { 1449 error = 0; 1450 goto out; 1451 } 1452 1453 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) 1454 return (EFBIG); 1455 1456 error = tmpfs_reg_resize(vp, length, FALSE); 1457 if (error == 0) { 1458 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; 1459 } 1460 1461 out: 1462 tmpfs_update(vp); 1463 1464 return error; 1465 }
Cache object: 7d9fa846918781e90d90cd627adacc72
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