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/fnv_hash.h> 41 #include <sys/lock.h> 42 #include <sys/namei.h> 43 #include <sys/priv.h> 44 #include <sys/proc.h> 45 #include <sys/rwlock.h> 46 #include <sys/stat.h> 47 #include <sys/systm.h> 48 #include <sys/sysctl.h> 49 #include <sys/vnode.h> 50 #include <sys/vmmeter.h> 51 52 #include <vm/vm.h> 53 #include <vm/vm_param.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_page.h> 56 #include <vm/vm_pageout.h> 57 #include <vm/vm_pager.h> 58 #include <vm/vm_extern.h> 59 60 #include <fs/tmpfs/tmpfs.h> 61 #include <fs/tmpfs/tmpfs_fifoops.h> 62 #include <fs/tmpfs/tmpfs_vnops.h> 63 64 struct tmpfs_dir_cursor { 65 struct tmpfs_dirent *tdc_current; 66 struct tmpfs_dirent *tdc_tree; 67 }; 68 69 SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW, 0, "tmpfs file system"); 70 71 static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED; 72 73 static int 74 sysctl_mem_reserved(SYSCTL_HANDLER_ARGS) 75 { 76 int error; 77 long pages, bytes; 78 79 pages = *(long *)arg1; 80 bytes = pages * PAGE_SIZE; 81 82 error = sysctl_handle_long(oidp, &bytes, 0, req); 83 if (error || !req->newptr) 84 return (error); 85 86 pages = bytes / PAGE_SIZE; 87 if (pages < TMPFS_PAGES_MINRESERVED) 88 return (EINVAL); 89 90 *(long *)arg1 = pages; 91 return (0); 92 } 93 94 SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_RW, 95 &tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L", 96 "Amount of available memory and swap below which tmpfs growth stops"); 97 98 static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a, 99 struct tmpfs_dirent *b); 100 RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); 101 102 size_t 103 tmpfs_mem_avail(void) 104 { 105 vm_ooffset_t avail; 106 107 avail = swap_pager_avail + cnt.v_free_count + cnt.v_cache_count - 108 tmpfs_pages_reserved; 109 if (__predict_false(avail < 0)) 110 avail = 0; 111 return (avail); 112 } 113 114 size_t 115 tmpfs_pages_used(struct tmpfs_mount *tmp) 116 { 117 const size_t node_size = sizeof(struct tmpfs_node) + 118 sizeof(struct tmpfs_dirent); 119 size_t meta_pages; 120 121 meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size, 122 PAGE_SIZE); 123 return (meta_pages + tmp->tm_pages_used); 124 } 125 126 static size_t 127 tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages) 128 { 129 if (tmpfs_mem_avail() < req_pages) 130 return (0); 131 132 if (tmp->tm_pages_max != SIZE_MAX && 133 tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp)) 134 return (0); 135 136 return (1); 137 } 138 139 /* --------------------------------------------------------------------- */ 140 141 /* 142 * Allocates a new node of type 'type' inside the 'tmp' mount point, with 143 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', 144 * using the credentials of the process 'p'. 145 * 146 * If the node type is set to 'VDIR', then the parent parameter must point 147 * to the parent directory of the node being created. It may only be NULL 148 * while allocating the root node. 149 * 150 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter 151 * specifies the device the node represents. 152 * 153 * If the node type is set to 'VLNK', then the parameter target specifies 154 * the file name of the target file for the symbolic link that is being 155 * created. 156 * 157 * Note that new nodes are retrieved from the available list if it has 158 * items or, if it is empty, from the node pool as long as there is enough 159 * space to create them. 160 * 161 * Returns zero on success or an appropriate error code on failure. 162 */ 163 int 164 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type, 165 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, 166 char *target, dev_t rdev, struct tmpfs_node **node) 167 { 168 struct tmpfs_node *nnode; 169 vm_object_t obj; 170 171 /* If the root directory of the 'tmp' file system is not yet 172 * allocated, this must be the request to do it. */ 173 MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); 174 175 MPASS(IFF(type == VLNK, target != NULL)); 176 MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL)); 177 178 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) 179 return (ENOSPC); 180 if (tmpfs_pages_check_avail(tmp, 1) == 0) 181 return (ENOSPC); 182 183 nnode = (struct tmpfs_node *)uma_zalloc_arg( 184 tmp->tm_node_pool, tmp, M_WAITOK); 185 186 /* Generic initialization. */ 187 nnode->tn_type = type; 188 vfs_timestamp(&nnode->tn_atime); 189 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = 190 nnode->tn_atime; 191 nnode->tn_uid = uid; 192 nnode->tn_gid = gid; 193 nnode->tn_mode = mode; 194 nnode->tn_id = alloc_unr(tmp->tm_ino_unr); 195 196 /* Type-specific initialization. */ 197 switch (nnode->tn_type) { 198 case VBLK: 199 case VCHR: 200 nnode->tn_rdev = rdev; 201 break; 202 203 case VDIR: 204 RB_INIT(&nnode->tn_dir.tn_dirhead); 205 LIST_INIT(&nnode->tn_dir.tn_dupindex); 206 MPASS(parent != nnode); 207 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL)); 208 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent; 209 nnode->tn_dir.tn_readdir_lastn = 0; 210 nnode->tn_dir.tn_readdir_lastp = NULL; 211 nnode->tn_links++; 212 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent); 213 nnode->tn_dir.tn_parent->tn_links++; 214 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent); 215 break; 216 217 case VFIFO: 218 /* FALLTHROUGH */ 219 case VSOCK: 220 break; 221 222 case VLNK: 223 MPASS(strlen(target) < MAXPATHLEN); 224 nnode->tn_size = strlen(target); 225 nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME, 226 M_WAITOK); 227 memcpy(nnode->tn_link, target, nnode->tn_size); 228 break; 229 230 case VREG: 231 obj = nnode->tn_reg.tn_aobj = 232 vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0, 233 NULL /* XXXKIB - tmpfs needs swap reservation */); 234 VM_OBJECT_WLOCK(obj); 235 /* OBJ_TMPFS is set together with the setting of vp->v_object */ 236 vm_object_set_flag(obj, OBJ_NOSPLIT); 237 vm_object_clear_flag(obj, OBJ_ONEMAPPING); 238 VM_OBJECT_WUNLOCK(obj); 239 break; 240 241 default: 242 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); 243 } 244 245 TMPFS_LOCK(tmp); 246 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); 247 tmp->tm_nodes_inuse++; 248 TMPFS_UNLOCK(tmp); 249 250 *node = nnode; 251 return 0; 252 } 253 254 /* --------------------------------------------------------------------- */ 255 256 /* 257 * Destroys the node pointed to by node from the file system 'tmp'. 258 * If the node does not belong to the given mount point, the results are 259 * unpredicted. 260 * 261 * If the node references a directory; no entries are allowed because 262 * their removal could need a recursive algorithm, something forbidden in 263 * kernel space. Furthermore, there is not need to provide such 264 * functionality (recursive removal) because the only primitives offered 265 * to the user are the removal of empty directories and the deletion of 266 * individual files. 267 * 268 * Note that nodes are not really deleted; in fact, when a node has been 269 * allocated, it cannot be deleted during the whole life of the file 270 * system. Instead, they are moved to the available list and remain there 271 * until reused. 272 */ 273 void 274 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) 275 { 276 vm_object_t uobj; 277 278 #ifdef INVARIANTS 279 TMPFS_NODE_LOCK(node); 280 MPASS(node->tn_vnode == NULL); 281 MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0); 282 TMPFS_NODE_UNLOCK(node); 283 #endif 284 285 TMPFS_LOCK(tmp); 286 LIST_REMOVE(node, tn_entries); 287 tmp->tm_nodes_inuse--; 288 TMPFS_UNLOCK(tmp); 289 290 switch (node->tn_type) { 291 case VNON: 292 /* Do not do anything. VNON is provided to let the 293 * allocation routine clean itself easily by avoiding 294 * duplicating code in it. */ 295 /* FALLTHROUGH */ 296 case VBLK: 297 /* FALLTHROUGH */ 298 case VCHR: 299 /* FALLTHROUGH */ 300 case VDIR: 301 /* FALLTHROUGH */ 302 case VFIFO: 303 /* FALLTHROUGH */ 304 case VSOCK: 305 break; 306 307 case VLNK: 308 free(node->tn_link, M_TMPFSNAME); 309 break; 310 311 case VREG: 312 uobj = node->tn_reg.tn_aobj; 313 if (uobj != NULL) { 314 TMPFS_LOCK(tmp); 315 tmp->tm_pages_used -= uobj->size; 316 TMPFS_UNLOCK(tmp); 317 vm_object_deallocate(uobj); 318 } 319 break; 320 321 default: 322 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); 323 } 324 325 free_unr(tmp->tm_ino_unr, node->tn_id); 326 uma_zfree(tmp->tm_node_pool, node); 327 } 328 329 /* --------------------------------------------------------------------- */ 330 331 static __inline uint32_t 332 tmpfs_dirent_hash(const char *name, u_int len) 333 { 334 uint32_t hash; 335 336 hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK; 337 #ifdef TMPFS_DEBUG_DIRCOOKIE_DUP 338 hash &= 0xf; 339 #endif 340 if (hash < TMPFS_DIRCOOKIE_MIN) 341 hash += TMPFS_DIRCOOKIE_MIN; 342 343 return (hash); 344 } 345 346 static __inline off_t 347 tmpfs_dirent_cookie(struct tmpfs_dirent *de) 348 { 349 MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN); 350 351 return (de->td_cookie); 352 } 353 354 static __inline boolean_t 355 tmpfs_dirent_dup(struct tmpfs_dirent *de) 356 { 357 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0); 358 } 359 360 static __inline boolean_t 361 tmpfs_dirent_duphead(struct tmpfs_dirent *de) 362 { 363 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0); 364 } 365 366 void 367 tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen) 368 { 369 de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen); 370 memcpy(de->ud.td_name, name, namelen); 371 de->td_namelen = namelen; 372 } 373 374 /* 375 * Allocates a new directory entry for the node node with a name of name. 376 * The new directory entry is returned in *de. 377 * 378 * The link count of node is increased by one to reflect the new object 379 * referencing it. 380 * 381 * Returns zero on success or an appropriate error code on failure. 382 */ 383 int 384 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 385 const char *name, u_int len, struct tmpfs_dirent **de) 386 { 387 struct tmpfs_dirent *nde; 388 389 nde = uma_zalloc(tmp->tm_dirent_pool, M_WAITOK); 390 nde->td_node = node; 391 if (name != NULL) { 392 nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK); 393 tmpfs_dirent_init(nde, name, len); 394 } else 395 nde->td_namelen = 0; 396 if (node != NULL) 397 node->tn_links++; 398 399 *de = nde; 400 401 return 0; 402 } 403 404 /* --------------------------------------------------------------------- */ 405 406 /* 407 * Frees a directory entry. It is the caller's responsibility to destroy 408 * the node referenced by it if needed. 409 * 410 * The link count of node is decreased by one to reflect the removal of an 411 * object that referenced it. This only happens if 'node_exists' is true; 412 * otherwise the function will not access the node referred to by the 413 * directory entry, as it may already have been released from the outside. 414 */ 415 void 416 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de) 417 { 418 struct tmpfs_node *node; 419 420 node = de->td_node; 421 if (node != NULL) { 422 MPASS(node->tn_links > 0); 423 node->tn_links--; 424 } 425 if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL) 426 free(de->ud.td_name, M_TMPFSNAME); 427 uma_zfree(tmp->tm_dirent_pool, de); 428 } 429 430 /* --------------------------------------------------------------------- */ 431 432 void 433 tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj) 434 { 435 436 if (vp->v_type != VREG || obj == NULL) 437 return; 438 439 VM_OBJECT_WLOCK(obj); 440 VI_LOCK(vp); 441 vm_object_clear_flag(obj, OBJ_TMPFS); 442 obj->un_pager.swp.swp_tmpfs = NULL; 443 VI_UNLOCK(vp); 444 VM_OBJECT_WUNLOCK(obj); 445 } 446 447 /* 448 * Need to clear v_object for insmntque failure. 449 */ 450 static void 451 tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg) 452 { 453 454 tmpfs_destroy_vobject(vp, vp->v_object); 455 vp->v_object = NULL; 456 vp->v_data = NULL; 457 vp->v_op = &dead_vnodeops; 458 vgone(vp); 459 vput(vp); 460 } 461 462 /* 463 * Allocates a new vnode for the node node or returns a new reference to 464 * an existing one if the node had already a vnode referencing it. The 465 * resulting locked vnode is returned in *vpp. 466 * 467 * Returns zero on success or an appropriate error code on failure. 468 */ 469 int 470 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag, 471 struct vnode **vpp) 472 { 473 struct vnode *vp; 474 vm_object_t object; 475 int error; 476 477 error = 0; 478 loop: 479 TMPFS_NODE_LOCK(node); 480 if ((vp = node->tn_vnode) != NULL) { 481 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); 482 VI_LOCK(vp); 483 TMPFS_NODE_UNLOCK(node); 484 error = vget(vp, lkflag | LK_INTERLOCK, curthread); 485 if (error != 0) { 486 vp = NULL; 487 goto out; 488 } 489 490 /* 491 * Make sure the vnode is still there after 492 * getting the interlock to avoid racing a free. 493 */ 494 if (node->tn_vnode == NULL || node->tn_vnode != vp) { 495 vput(vp); 496 goto loop; 497 } 498 499 goto out; 500 } 501 502 if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) || 503 (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) { 504 TMPFS_NODE_UNLOCK(node); 505 error = ENOENT; 506 vp = NULL; 507 goto out; 508 } 509 510 /* 511 * otherwise lock the vp list while we call getnewvnode 512 * since that can block. 513 */ 514 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) { 515 node->tn_vpstate |= TMPFS_VNODE_WANT; 516 error = msleep((caddr_t) &node->tn_vpstate, 517 TMPFS_NODE_MTX(node), PDROP | PCATCH, 518 "tmpfs_alloc_vp", 0); 519 if (error) 520 return error; 521 522 goto loop; 523 } else 524 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING; 525 526 TMPFS_NODE_UNLOCK(node); 527 528 /* Get a new vnode and associate it with our node. */ 529 error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp); 530 if (error != 0) 531 goto unlock; 532 MPASS(vp != NULL); 533 534 (void) vn_lock(vp, lkflag | LK_RETRY); 535 536 vp->v_data = node; 537 vp->v_type = node->tn_type; 538 539 /* Type-specific initialization. */ 540 switch (node->tn_type) { 541 case VBLK: 542 /* FALLTHROUGH */ 543 case VCHR: 544 /* FALLTHROUGH */ 545 case VLNK: 546 /* FALLTHROUGH */ 547 case VSOCK: 548 break; 549 case VFIFO: 550 vp->v_op = &tmpfs_fifoop_entries; 551 break; 552 case VREG: 553 object = node->tn_reg.tn_aobj; 554 VM_OBJECT_WLOCK(object); 555 VI_LOCK(vp); 556 KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs")); 557 vp->v_object = object; 558 object->un_pager.swp.swp_tmpfs = vp; 559 vm_object_set_flag(object, OBJ_TMPFS); 560 VI_UNLOCK(vp); 561 VM_OBJECT_WUNLOCK(object); 562 break; 563 case VDIR: 564 MPASS(node->tn_dir.tn_parent != NULL); 565 if (node->tn_dir.tn_parent == node) 566 vp->v_vflag |= VV_ROOT; 567 break; 568 569 default: 570 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); 571 } 572 573 error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL); 574 if (error) 575 vp = NULL; 576 577 unlock: 578 TMPFS_NODE_LOCK(node); 579 580 MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING); 581 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING; 582 node->tn_vnode = vp; 583 584 if (node->tn_vpstate & TMPFS_VNODE_WANT) { 585 node->tn_vpstate &= ~TMPFS_VNODE_WANT; 586 TMPFS_NODE_UNLOCK(node); 587 wakeup((caddr_t) &node->tn_vpstate); 588 } else 589 TMPFS_NODE_UNLOCK(node); 590 591 out: 592 *vpp = vp; 593 594 #ifdef INVARIANTS 595 if (error == 0) { 596 MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp)); 597 TMPFS_NODE_LOCK(node); 598 MPASS(*vpp == node->tn_vnode); 599 TMPFS_NODE_UNLOCK(node); 600 } 601 #endif 602 603 return error; 604 } 605 606 /* --------------------------------------------------------------------- */ 607 608 /* 609 * Destroys the association between the vnode vp and the node it 610 * references. 611 */ 612 void 613 tmpfs_free_vp(struct vnode *vp) 614 { 615 struct tmpfs_node *node; 616 617 node = VP_TO_TMPFS_NODE(vp); 618 619 mtx_assert(TMPFS_NODE_MTX(node), MA_OWNED); 620 node->tn_vnode = NULL; 621 vp->v_data = NULL; 622 } 623 624 /* --------------------------------------------------------------------- */ 625 626 /* 627 * Allocates a new file of type 'type' and adds it to the parent directory 628 * 'dvp'; this addition is done using the component name given in 'cnp'. 629 * The ownership of the new file is automatically assigned based on the 630 * credentials of the caller (through 'cnp'), the group is set based on 631 * the parent directory and the mode is determined from the 'vap' argument. 632 * If successful, *vpp holds a vnode to the newly created file and zero 633 * is returned. Otherwise *vpp is NULL and the function returns an 634 * appropriate error code. 635 */ 636 int 637 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 638 struct componentname *cnp, char *target) 639 { 640 int error; 641 struct tmpfs_dirent *de; 642 struct tmpfs_mount *tmp; 643 struct tmpfs_node *dnode; 644 struct tmpfs_node *node; 645 struct tmpfs_node *parent; 646 647 MPASS(VOP_ISLOCKED(dvp)); 648 MPASS(cnp->cn_flags & HASBUF); 649 650 tmp = VFS_TO_TMPFS(dvp->v_mount); 651 dnode = VP_TO_TMPFS_DIR(dvp); 652 *vpp = NULL; 653 654 /* If the entry we are creating is a directory, we cannot overflow 655 * the number of links of its parent, because it will get a new 656 * link. */ 657 if (vap->va_type == VDIR) { 658 /* Ensure that we do not overflow the maximum number of links 659 * imposed by the system. */ 660 MPASS(dnode->tn_links <= LINK_MAX); 661 if (dnode->tn_links == LINK_MAX) { 662 error = EMLINK; 663 goto out; 664 } 665 666 parent = dnode; 667 MPASS(parent != NULL); 668 } else 669 parent = NULL; 670 671 /* Allocate a node that represents the new file. */ 672 error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid, 673 dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node); 674 if (error != 0) 675 goto out; 676 677 /* Allocate a directory entry that points to the new file. */ 678 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, 679 &de); 680 if (error != 0) { 681 tmpfs_free_node(tmp, node); 682 goto out; 683 } 684 685 /* Allocate a vnode for the new file. */ 686 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp); 687 if (error != 0) { 688 tmpfs_free_dirent(tmp, de); 689 tmpfs_free_node(tmp, node); 690 goto out; 691 } 692 693 /* Now that all required items are allocated, we can proceed to 694 * insert the new node into the directory, an operation that 695 * cannot fail. */ 696 if (cnp->cn_flags & ISWHITEOUT) 697 tmpfs_dir_whiteout_remove(dvp, cnp); 698 tmpfs_dir_attach(dvp, de); 699 700 out: 701 702 return error; 703 } 704 705 /* --------------------------------------------------------------------- */ 706 707 static struct tmpfs_dirent * 708 tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) 709 { 710 struct tmpfs_dirent *de; 711 712 de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead); 713 dc->tdc_tree = de; 714 if (de != NULL && tmpfs_dirent_duphead(de)) 715 de = LIST_FIRST(&de->ud.td_duphead); 716 dc->tdc_current = de; 717 718 return (dc->tdc_current); 719 } 720 721 static struct tmpfs_dirent * 722 tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) 723 { 724 struct tmpfs_dirent *de; 725 726 MPASS(dc->tdc_tree != NULL); 727 if (tmpfs_dirent_dup(dc->tdc_current)) { 728 dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries); 729 if (dc->tdc_current != NULL) 730 return (dc->tdc_current); 731 } 732 dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir, 733 &dnode->tn_dir.tn_dirhead, dc->tdc_tree); 734 if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) { 735 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); 736 MPASS(dc->tdc_current != NULL); 737 } 738 739 return (dc->tdc_current); 740 } 741 742 /* Lookup directory entry in RB-Tree. Function may return duphead entry. */ 743 static struct tmpfs_dirent * 744 tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash) 745 { 746 struct tmpfs_dirent *de, dekey; 747 748 dekey.td_hash = hash; 749 de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey); 750 return (de); 751 } 752 753 /* Lookup directory entry by cookie, initialize directory cursor accordingly. */ 754 static struct tmpfs_dirent * 755 tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie, 756 struct tmpfs_dir_cursor *dc) 757 { 758 struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead; 759 struct tmpfs_dirent *de, dekey; 760 761 MPASS(cookie >= TMPFS_DIRCOOKIE_MIN); 762 763 if (cookie == node->tn_dir.tn_readdir_lastn && 764 (de = node->tn_dir.tn_readdir_lastp) != NULL) { 765 /* Protect against possible race, tn_readdir_last[pn] 766 * may be updated with only shared vnode lock held. */ 767 if (cookie == tmpfs_dirent_cookie(de)) 768 goto out; 769 } 770 771 if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) { 772 LIST_FOREACH(de, &node->tn_dir.tn_dupindex, 773 uh.td_dup.index_entries) { 774 MPASS(tmpfs_dirent_dup(de)); 775 if (de->td_cookie == cookie) 776 goto out; 777 /* dupindex list is sorted. */ 778 if (de->td_cookie < cookie) { 779 de = NULL; 780 goto out; 781 } 782 } 783 MPASS(de == NULL); 784 goto out; 785 } 786 787 MPASS((cookie & TMPFS_DIRCOOKIE_MASK) == cookie); 788 dekey.td_hash = cookie; 789 /* Recover if direntry for cookie was removed */ 790 de = RB_NFIND(tmpfs_dir, dirhead, &dekey); 791 dc->tdc_tree = de; 792 dc->tdc_current = de; 793 if (de != NULL && tmpfs_dirent_duphead(de)) { 794 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); 795 MPASS(dc->tdc_current != NULL); 796 } 797 return (dc->tdc_current); 798 799 out: 800 dc->tdc_tree = de; 801 dc->tdc_current = de; 802 if (de != NULL && tmpfs_dirent_dup(de)) 803 dc->tdc_tree = tmpfs_dir_xlookup_hash(node, 804 de->td_hash); 805 return (dc->tdc_current); 806 } 807 808 /* 809 * Looks for a directory entry in the directory represented by node. 810 * 'cnp' describes the name of the entry to look for. Note that the . 811 * and .. components are not allowed as they do not physically exist 812 * within directories. 813 * 814 * Returns a pointer to the entry when found, otherwise NULL. 815 */ 816 struct tmpfs_dirent * 817 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, 818 struct componentname *cnp) 819 { 820 struct tmpfs_dir_duphead *duphead; 821 struct tmpfs_dirent *de; 822 uint32_t hash; 823 824 MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); 825 MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && 826 cnp->cn_nameptr[1] == '.'))); 827 TMPFS_VALIDATE_DIR(node); 828 829 hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen); 830 de = tmpfs_dir_xlookup_hash(node, hash); 831 if (de != NULL && tmpfs_dirent_duphead(de)) { 832 duphead = &de->ud.td_duphead; 833 LIST_FOREACH(de, duphead, uh.td_dup.entries) { 834 if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, 835 cnp->cn_namelen)) 836 break; 837 } 838 } else if (de != NULL) { 839 if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, 840 cnp->cn_namelen)) 841 de = NULL; 842 } 843 if (de != NULL && f != NULL && de->td_node != f) 844 de = NULL; 845 846 return (de); 847 } 848 849 /* 850 * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex 851 * list, allocate new cookie value. 852 */ 853 static void 854 tmpfs_dir_attach_dup(struct tmpfs_node *dnode, 855 struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde) 856 { 857 struct tmpfs_dir_duphead *dupindex; 858 struct tmpfs_dirent *de, *pde; 859 860 dupindex = &dnode->tn_dir.tn_dupindex; 861 de = LIST_FIRST(dupindex); 862 if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) { 863 if (de == NULL) 864 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; 865 else 866 nde->td_cookie = de->td_cookie + 1; 867 MPASS(tmpfs_dirent_dup(nde)); 868 LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries); 869 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 870 return; 871 } 872 873 /* 874 * Cookie numbers are near exhaustion. Scan dupindex list for unused 875 * numbers. dupindex list is sorted in descending order. Keep it so 876 * after inserting nde. 877 */ 878 while (1) { 879 pde = de; 880 de = LIST_NEXT(de, uh.td_dup.index_entries); 881 if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) { 882 /* 883 * Last element of the index doesn't have minimal cookie 884 * value, use it. 885 */ 886 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; 887 LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries); 888 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 889 return; 890 } else if (de == NULL) { 891 /* 892 * We are so lucky have 2^30 hash duplicates in single 893 * directory :) Return largest possible cookie value. 894 * It should be fine except possible issues with 895 * VOP_READDIR restart. 896 */ 897 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX; 898 LIST_INSERT_HEAD(dupindex, nde, 899 uh.td_dup.index_entries); 900 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 901 return; 902 } 903 if (de->td_cookie + 1 == pde->td_cookie || 904 de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX) 905 continue; /* No hole or invalid cookie. */ 906 nde->td_cookie = de->td_cookie + 1; 907 MPASS(tmpfs_dirent_dup(nde)); 908 MPASS(pde->td_cookie > nde->td_cookie); 909 MPASS(nde->td_cookie > de->td_cookie); 910 LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries); 911 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 912 return; 913 }; 914 } 915 916 /* 917 * Attaches the directory entry de to the directory represented by vp. 918 * Note that this does not change the link count of the node pointed by 919 * the directory entry, as this is done by tmpfs_alloc_dirent. 920 */ 921 void 922 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) 923 { 924 struct tmpfs_node *dnode; 925 struct tmpfs_dirent *xde, *nde; 926 927 ASSERT_VOP_ELOCKED(vp, __func__); 928 MPASS(de->td_namelen > 0); 929 MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN); 930 MPASS(de->td_cookie == de->td_hash); 931 932 dnode = VP_TO_TMPFS_DIR(vp); 933 dnode->tn_dir.tn_readdir_lastn = 0; 934 dnode->tn_dir.tn_readdir_lastp = NULL; 935 936 MPASS(!tmpfs_dirent_dup(de)); 937 xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); 938 if (xde != NULL && tmpfs_dirent_duphead(xde)) 939 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); 940 else if (xde != NULL) { 941 /* 942 * Allocate new duphead. Swap xde with duphead to avoid 943 * adding/removing elements with the same hash. 944 */ 945 MPASS(!tmpfs_dirent_dup(xde)); 946 tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0, 947 &nde); 948 /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */ 949 memcpy(nde, xde, sizeof(*xde)); 950 xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD; 951 LIST_INIT(&xde->ud.td_duphead); 952 xde->td_namelen = 0; 953 xde->td_node = NULL; 954 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde); 955 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); 956 } 957 dnode->tn_size += sizeof(struct tmpfs_dirent); 958 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 959 TMPFS_NODE_MODIFIED; 960 } 961 962 /* --------------------------------------------------------------------- */ 963 964 /* 965 * Detaches the directory entry de from the directory represented by vp. 966 * Note that this does not change the link count of the node pointed by 967 * the directory entry, as this is done by tmpfs_free_dirent. 968 */ 969 void 970 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) 971 { 972 struct tmpfs_mount *tmp; 973 struct tmpfs_dir *head; 974 struct tmpfs_node *dnode; 975 struct tmpfs_dirent *xde; 976 977 ASSERT_VOP_ELOCKED(vp, __func__); 978 979 dnode = VP_TO_TMPFS_DIR(vp); 980 head = &dnode->tn_dir.tn_dirhead; 981 dnode->tn_dir.tn_readdir_lastn = 0; 982 dnode->tn_dir.tn_readdir_lastp = NULL; 983 984 if (tmpfs_dirent_dup(de)) { 985 /* Remove duphead if de was last entry. */ 986 if (LIST_NEXT(de, uh.td_dup.entries) == NULL) { 987 xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash); 988 MPASS(tmpfs_dirent_duphead(xde)); 989 } else 990 xde = NULL; 991 LIST_REMOVE(de, uh.td_dup.entries); 992 LIST_REMOVE(de, uh.td_dup.index_entries); 993 if (xde != NULL) { 994 if (LIST_EMPTY(&xde->ud.td_duphead)) { 995 RB_REMOVE(tmpfs_dir, head, xde); 996 tmp = VFS_TO_TMPFS(vp->v_mount); 997 MPASS(xde->td_node == NULL); 998 tmpfs_free_dirent(tmp, xde); 999 } 1000 } 1001 } else 1002 RB_REMOVE(tmpfs_dir, head, de); 1003 1004 dnode->tn_size -= sizeof(struct tmpfs_dirent); 1005 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 1006 TMPFS_NODE_MODIFIED; 1007 } 1008 1009 void 1010 tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode) 1011 { 1012 struct tmpfs_dirent *de, *dde, *nde; 1013 1014 RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) { 1015 RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); 1016 /* Node may already be destroyed. */ 1017 de->td_node = NULL; 1018 if (tmpfs_dirent_duphead(de)) { 1019 while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) { 1020 LIST_REMOVE(dde, uh.td_dup.entries); 1021 dde->td_node = NULL; 1022 tmpfs_free_dirent(tmp, dde); 1023 } 1024 } 1025 tmpfs_free_dirent(tmp, de); 1026 } 1027 } 1028 1029 /* --------------------------------------------------------------------- */ 1030 1031 /* 1032 * Helper function for tmpfs_readdir. Creates a '.' entry for the given 1033 * directory and returns it in the uio space. The function returns 0 1034 * on success, -1 if there was not enough space in the uio structure to 1035 * hold the directory entry or an appropriate error code if another 1036 * error happens. 1037 */ 1038 static int 1039 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) 1040 { 1041 int error; 1042 struct dirent dent; 1043 1044 TMPFS_VALIDATE_DIR(node); 1045 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); 1046 1047 dent.d_fileno = node->tn_id; 1048 dent.d_type = DT_DIR; 1049 dent.d_namlen = 1; 1050 dent.d_name[0] = '.'; 1051 dent.d_name[1] = '\0'; 1052 dent.d_reclen = GENERIC_DIRSIZ(&dent); 1053 1054 if (dent.d_reclen > uio->uio_resid) 1055 error = EJUSTRETURN; 1056 else 1057 error = uiomove(&dent, dent.d_reclen, uio); 1058 1059 node->tn_status |= TMPFS_NODE_ACCESSED; 1060 1061 return error; 1062 } 1063 1064 /* --------------------------------------------------------------------- */ 1065 1066 /* 1067 * Helper function for tmpfs_readdir. Creates a '..' entry for the given 1068 * directory and returns it in the uio space. The function returns 0 1069 * on success, -1 if there was not enough space in the uio structure to 1070 * hold the directory entry or an appropriate error code if another 1071 * error happens. 1072 */ 1073 static int 1074 tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio) 1075 { 1076 int error; 1077 struct dirent dent; 1078 1079 TMPFS_VALIDATE_DIR(node); 1080 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); 1081 1082 /* 1083 * Return ENOENT if the current node is already removed. 1084 */ 1085 TMPFS_ASSERT_LOCKED(node); 1086 if (node->tn_dir.tn_parent == NULL) { 1087 return (ENOENT); 1088 } 1089 1090 TMPFS_NODE_LOCK(node->tn_dir.tn_parent); 1091 dent.d_fileno = node->tn_dir.tn_parent->tn_id; 1092 TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent); 1093 1094 dent.d_type = DT_DIR; 1095 dent.d_namlen = 2; 1096 dent.d_name[0] = '.'; 1097 dent.d_name[1] = '.'; 1098 dent.d_name[2] = '\0'; 1099 dent.d_reclen = GENERIC_DIRSIZ(&dent); 1100 1101 if (dent.d_reclen > uio->uio_resid) 1102 error = EJUSTRETURN; 1103 else 1104 error = uiomove(&dent, dent.d_reclen, uio); 1105 1106 node->tn_status |= TMPFS_NODE_ACCESSED; 1107 1108 return error; 1109 } 1110 1111 /* --------------------------------------------------------------------- */ 1112 1113 /* 1114 * Helper function for tmpfs_readdir. Returns as much directory entries 1115 * as can fit in the uio space. The read starts at uio->uio_offset. 1116 * The function returns 0 on success, -1 if there was not enough space 1117 * in the uio structure to hold the directory entry or an appropriate 1118 * error code if another error happens. 1119 */ 1120 int 1121 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, int cnt, 1122 u_long *cookies, int *ncookies) 1123 { 1124 struct tmpfs_dir_cursor dc; 1125 struct tmpfs_dirent *de; 1126 off_t off; 1127 int error; 1128 1129 TMPFS_VALIDATE_DIR(node); 1130 1131 off = 0; 1132 switch (uio->uio_offset) { 1133 case TMPFS_DIRCOOKIE_DOT: 1134 error = tmpfs_dir_getdotdent(node, uio); 1135 if (error != 0) 1136 return (error); 1137 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 1138 if (cnt != 0) 1139 cookies[(*ncookies)++] = off = uio->uio_offset; 1140 case TMPFS_DIRCOOKIE_DOTDOT: 1141 error = tmpfs_dir_getdotdotdent(node, uio); 1142 if (error != 0) 1143 return (error); 1144 de = tmpfs_dir_first(node, &dc); 1145 if (de == NULL) 1146 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 1147 else 1148 uio->uio_offset = tmpfs_dirent_cookie(de); 1149 if (cnt != 0) 1150 cookies[(*ncookies)++] = off = uio->uio_offset; 1151 if (de == NULL) 1152 return (0); 1153 break; 1154 case TMPFS_DIRCOOKIE_EOF: 1155 return (0); 1156 default: 1157 de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc); 1158 if (de == NULL) 1159 return (EINVAL); 1160 if (cnt != 0) 1161 off = tmpfs_dirent_cookie(de); 1162 } 1163 1164 /* Read as much entries as possible; i.e., until we reach the end of 1165 * the directory or we exhaust uio space. */ 1166 do { 1167 struct dirent d; 1168 1169 /* Create a dirent structure representing the current 1170 * tmpfs_node and fill it. */ 1171 if (de->td_node == NULL) { 1172 d.d_fileno = 1; 1173 d.d_type = DT_WHT; 1174 } else { 1175 d.d_fileno = de->td_node->tn_id; 1176 switch (de->td_node->tn_type) { 1177 case VBLK: 1178 d.d_type = DT_BLK; 1179 break; 1180 1181 case VCHR: 1182 d.d_type = DT_CHR; 1183 break; 1184 1185 case VDIR: 1186 d.d_type = DT_DIR; 1187 break; 1188 1189 case VFIFO: 1190 d.d_type = DT_FIFO; 1191 break; 1192 1193 case VLNK: 1194 d.d_type = DT_LNK; 1195 break; 1196 1197 case VREG: 1198 d.d_type = DT_REG; 1199 break; 1200 1201 case VSOCK: 1202 d.d_type = DT_SOCK; 1203 break; 1204 1205 default: 1206 panic("tmpfs_dir_getdents: type %p %d", 1207 de->td_node, (int)de->td_node->tn_type); 1208 } 1209 } 1210 d.d_namlen = de->td_namelen; 1211 MPASS(de->td_namelen < sizeof(d.d_name)); 1212 (void)memcpy(d.d_name, de->ud.td_name, de->td_namelen); 1213 d.d_name[de->td_namelen] = '\0'; 1214 d.d_reclen = GENERIC_DIRSIZ(&d); 1215 1216 /* Stop reading if the directory entry we are treating is 1217 * bigger than the amount of data that can be returned. */ 1218 if (d.d_reclen > uio->uio_resid) { 1219 error = EJUSTRETURN; 1220 break; 1221 } 1222 1223 /* Copy the new dirent structure into the output buffer and 1224 * advance pointers. */ 1225 error = uiomove(&d, d.d_reclen, uio); 1226 if (error == 0) { 1227 de = tmpfs_dir_next(node, &dc); 1228 if (cnt != 0) { 1229 if (de == NULL) 1230 off = TMPFS_DIRCOOKIE_EOF; 1231 else 1232 off = tmpfs_dirent_cookie(de); 1233 MPASS(*ncookies < cnt); 1234 cookies[(*ncookies)++] = off; 1235 } 1236 } 1237 } while (error == 0 && uio->uio_resid > 0 && de != NULL); 1238 1239 /* Update the offset and cache. */ 1240 if (cnt == 0) { 1241 if (de == NULL) 1242 off = TMPFS_DIRCOOKIE_EOF; 1243 else 1244 off = tmpfs_dirent_cookie(de); 1245 } 1246 1247 uio->uio_offset = off; 1248 node->tn_dir.tn_readdir_lastn = off; 1249 node->tn_dir.tn_readdir_lastp = de; 1250 1251 node->tn_status |= TMPFS_NODE_ACCESSED; 1252 return error; 1253 } 1254 1255 int 1256 tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp) 1257 { 1258 struct tmpfs_dirent *de; 1259 int error; 1260 1261 error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL, 1262 cnp->cn_nameptr, cnp->cn_namelen, &de); 1263 if (error != 0) 1264 return (error); 1265 tmpfs_dir_attach(dvp, de); 1266 return (0); 1267 } 1268 1269 void 1270 tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) 1271 { 1272 struct tmpfs_dirent *de; 1273 1274 de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp); 1275 MPASS(de != NULL && de->td_node == NULL); 1276 tmpfs_dir_detach(dvp, de); 1277 tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de); 1278 } 1279 1280 /* --------------------------------------------------------------------- */ 1281 1282 /* 1283 * Resizes the aobj associated with the regular file pointed to by 'vp' to the 1284 * size 'newsize'. 'vp' must point to a vnode that represents a regular file. 1285 * 'newsize' must be positive. 1286 * 1287 * Returns zero on success or an appropriate error code on failure. 1288 */ 1289 int 1290 tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) 1291 { 1292 struct tmpfs_mount *tmp; 1293 struct tmpfs_node *node; 1294 vm_object_t uobj; 1295 vm_page_t m, ma[1]; 1296 vm_pindex_t idx, newpages, oldpages; 1297 off_t oldsize; 1298 int base, rv; 1299 1300 MPASS(vp->v_type == VREG); 1301 MPASS(newsize >= 0); 1302 1303 node = VP_TO_TMPFS_NODE(vp); 1304 uobj = node->tn_reg.tn_aobj; 1305 tmp = VFS_TO_TMPFS(vp->v_mount); 1306 1307 /* 1308 * Convert the old and new sizes to the number of pages needed to 1309 * store them. It may happen that we do not need to do anything 1310 * because the last allocated page can accommodate the change on 1311 * its own. 1312 */ 1313 oldsize = node->tn_size; 1314 oldpages = OFF_TO_IDX(oldsize + PAGE_MASK); 1315 MPASS(oldpages == uobj->size); 1316 newpages = OFF_TO_IDX(newsize + PAGE_MASK); 1317 if (newpages > oldpages && 1318 tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0) 1319 return (ENOSPC); 1320 1321 VM_OBJECT_WLOCK(uobj); 1322 if (newsize < oldsize) { 1323 /* 1324 * Zero the truncated part of the last page. 1325 */ 1326 base = newsize & PAGE_MASK; 1327 if (base != 0) { 1328 idx = OFF_TO_IDX(newsize); 1329 retry: 1330 m = vm_page_lookup(uobj, idx); 1331 if (m != NULL) { 1332 if ((m->oflags & VPO_BUSY) != 0 || 1333 m->busy != 0) { 1334 vm_page_sleep(m, "tmfssz"); 1335 goto retry; 1336 } 1337 MPASS(m->valid == VM_PAGE_BITS_ALL); 1338 } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { 1339 m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL); 1340 if (m == NULL) { 1341 VM_OBJECT_WUNLOCK(uobj); 1342 VM_WAIT; 1343 VM_OBJECT_WLOCK(uobj); 1344 goto retry; 1345 } else if (m->valid != VM_PAGE_BITS_ALL) { 1346 ma[0] = m; 1347 rv = vm_pager_get_pages(uobj, ma, 1, 0); 1348 m = vm_page_lookup(uobj, idx); 1349 } else 1350 /* A cached page was reactivated. */ 1351 rv = VM_PAGER_OK; 1352 vm_page_lock(m); 1353 if (rv == VM_PAGER_OK) { 1354 vm_page_deactivate(m); 1355 vm_page_unlock(m); 1356 vm_page_wakeup(m); 1357 } else { 1358 vm_page_free(m); 1359 vm_page_unlock(m); 1360 if (ignerr) 1361 m = NULL; 1362 else { 1363 VM_OBJECT_WUNLOCK(uobj); 1364 return (EIO); 1365 } 1366 } 1367 } 1368 if (m != NULL) { 1369 pmap_zero_page_area(m, base, PAGE_SIZE - base); 1370 vm_page_dirty(m); 1371 vm_pager_page_unswapped(m); 1372 } 1373 } 1374 1375 /* 1376 * Release any swap space and free any whole pages. 1377 */ 1378 if (newpages < oldpages) { 1379 swap_pager_freespace(uobj, newpages, oldpages - 1380 newpages); 1381 vm_object_page_remove(uobj, newpages, 0, 0); 1382 } 1383 } 1384 uobj->size = newpages; 1385 VM_OBJECT_WUNLOCK(uobj); 1386 1387 TMPFS_LOCK(tmp); 1388 tmp->tm_pages_used += (newpages - oldpages); 1389 TMPFS_UNLOCK(tmp); 1390 1391 node->tn_size = newsize; 1392 return (0); 1393 } 1394 1395 /* --------------------------------------------------------------------- */ 1396 1397 /* 1398 * Change flags of the given vnode. 1399 * Caller should execute tmpfs_update on vp after a successful execution. 1400 * The vnode must be locked on entry and remain locked on exit. 1401 */ 1402 int 1403 tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred, 1404 struct thread *p) 1405 { 1406 int error; 1407 struct tmpfs_node *node; 1408 1409 MPASS(VOP_ISLOCKED(vp)); 1410 1411 node = VP_TO_TMPFS_NODE(vp); 1412 1413 if ((flags & ~(UF_NODUMP | UF_IMMUTABLE | UF_APPEND | UF_OPAQUE | 1414 UF_NOUNLINK | SF_ARCHIVED | SF_IMMUTABLE | SF_APPEND | 1415 SF_NOUNLINK)) != 0) 1416 return (EOPNOTSUPP); 1417 1418 /* Disallow this operation if the file system is mounted read-only. */ 1419 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1420 return EROFS; 1421 1422 /* 1423 * Callers may only modify the file flags on objects they 1424 * have VADMIN rights for. 1425 */ 1426 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1427 return (error); 1428 /* 1429 * Unprivileged processes are not permitted to unset system 1430 * flags, or modify flags if any system flags are set. 1431 */ 1432 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) { 1433 if (node->tn_flags & 1434 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) { 1435 error = securelevel_gt(cred, 0); 1436 if (error) 1437 return (error); 1438 } 1439 } else { 1440 if (node->tn_flags & 1441 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || 1442 ((flags ^ node->tn_flags) & SF_SETTABLE)) 1443 return (EPERM); 1444 } 1445 node->tn_flags = flags; 1446 node->tn_status |= TMPFS_NODE_CHANGED; 1447 1448 MPASS(VOP_ISLOCKED(vp)); 1449 1450 return 0; 1451 } 1452 1453 /* --------------------------------------------------------------------- */ 1454 1455 /* 1456 * Change access mode on the given vnode. 1457 * Caller should execute tmpfs_update on vp after a successful execution. 1458 * The vnode must be locked on entry and remain locked on exit. 1459 */ 1460 int 1461 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p) 1462 { 1463 int error; 1464 struct tmpfs_node *node; 1465 1466 MPASS(VOP_ISLOCKED(vp)); 1467 1468 node = VP_TO_TMPFS_NODE(vp); 1469 1470 /* Disallow this operation if the file system is mounted read-only. */ 1471 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1472 return EROFS; 1473 1474 /* Immutable or append-only files cannot be modified, either. */ 1475 if (node->tn_flags & (IMMUTABLE | APPEND)) 1476 return EPERM; 1477 1478 /* 1479 * To modify the permissions on a file, must possess VADMIN 1480 * for that file. 1481 */ 1482 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1483 return (error); 1484 1485 /* 1486 * Privileged processes may set the sticky bit on non-directories, 1487 * as well as set the setgid bit on a file with a group that the 1488 * process is not a member of. 1489 */ 1490 if (vp->v_type != VDIR && (mode & S_ISTXT)) { 1491 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0)) 1492 return (EFTYPE); 1493 } 1494 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) { 1495 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0); 1496 if (error) 1497 return (error); 1498 } 1499 1500 1501 node->tn_mode &= ~ALLPERMS; 1502 node->tn_mode |= mode & ALLPERMS; 1503 1504 node->tn_status |= TMPFS_NODE_CHANGED; 1505 1506 MPASS(VOP_ISLOCKED(vp)); 1507 1508 return 0; 1509 } 1510 1511 /* --------------------------------------------------------------------- */ 1512 1513 /* 1514 * Change ownership of the given vnode. At least one of uid or gid must 1515 * be different than VNOVAL. If one is set to that value, the attribute 1516 * is unchanged. 1517 * Caller should execute tmpfs_update on vp after a successful execution. 1518 * The vnode must be locked on entry and remain locked on exit. 1519 */ 1520 int 1521 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, 1522 struct thread *p) 1523 { 1524 int error; 1525 struct tmpfs_node *node; 1526 uid_t ouid; 1527 gid_t ogid; 1528 1529 MPASS(VOP_ISLOCKED(vp)); 1530 1531 node = VP_TO_TMPFS_NODE(vp); 1532 1533 /* Assign default values if they are unknown. */ 1534 MPASS(uid != VNOVAL || gid != VNOVAL); 1535 if (uid == VNOVAL) 1536 uid = node->tn_uid; 1537 if (gid == VNOVAL) 1538 gid = node->tn_gid; 1539 MPASS(uid != VNOVAL && gid != VNOVAL); 1540 1541 /* Disallow this operation if the file system is mounted read-only. */ 1542 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1543 return EROFS; 1544 1545 /* Immutable or append-only files cannot be modified, either. */ 1546 if (node->tn_flags & (IMMUTABLE | APPEND)) 1547 return EPERM; 1548 1549 /* 1550 * To modify the ownership of a file, must possess VADMIN for that 1551 * file. 1552 */ 1553 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1554 return (error); 1555 1556 /* 1557 * To change the owner of a file, or change the group of a file to a 1558 * group of which we are not a member, the caller must have 1559 * privilege. 1560 */ 1561 if ((uid != node->tn_uid || 1562 (gid != node->tn_gid && !groupmember(gid, cred))) && 1563 (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0))) 1564 return (error); 1565 1566 ogid = node->tn_gid; 1567 ouid = node->tn_uid; 1568 1569 node->tn_uid = uid; 1570 node->tn_gid = gid; 1571 1572 node->tn_status |= TMPFS_NODE_CHANGED; 1573 1574 if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) { 1575 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0)) 1576 node->tn_mode &= ~(S_ISUID | S_ISGID); 1577 } 1578 1579 MPASS(VOP_ISLOCKED(vp)); 1580 1581 return 0; 1582 } 1583 1584 /* --------------------------------------------------------------------- */ 1585 1586 /* 1587 * Change size of the given vnode. 1588 * Caller should execute tmpfs_update on vp after a successful execution. 1589 * The vnode must be locked on entry and remain locked on exit. 1590 */ 1591 int 1592 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, 1593 struct thread *p) 1594 { 1595 int error; 1596 struct tmpfs_node *node; 1597 1598 MPASS(VOP_ISLOCKED(vp)); 1599 1600 node = VP_TO_TMPFS_NODE(vp); 1601 1602 /* Decide whether this is a valid operation based on the file type. */ 1603 error = 0; 1604 switch (vp->v_type) { 1605 case VDIR: 1606 return EISDIR; 1607 1608 case VREG: 1609 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1610 return EROFS; 1611 break; 1612 1613 case VBLK: 1614 /* FALLTHROUGH */ 1615 case VCHR: 1616 /* FALLTHROUGH */ 1617 case VFIFO: 1618 /* Allow modifications of special files even if in the file 1619 * system is mounted read-only (we are not modifying the 1620 * files themselves, but the objects they represent). */ 1621 return 0; 1622 1623 default: 1624 /* Anything else is unsupported. */ 1625 return EOPNOTSUPP; 1626 } 1627 1628 /* Immutable or append-only files cannot be modified, either. */ 1629 if (node->tn_flags & (IMMUTABLE | APPEND)) 1630 return EPERM; 1631 1632 error = tmpfs_truncate(vp, size); 1633 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents 1634 * for us, as will update tn_status; no need to do that here. */ 1635 1636 MPASS(VOP_ISLOCKED(vp)); 1637 1638 return error; 1639 } 1640 1641 /* --------------------------------------------------------------------- */ 1642 1643 /* 1644 * Change access and modification times of the given vnode. 1645 * Caller should execute tmpfs_update on vp after a successful execution. 1646 * The vnode must be locked on entry and remain locked on exit. 1647 */ 1648 int 1649 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime, 1650 struct timespec *birthtime, int vaflags, struct ucred *cred, struct thread *l) 1651 { 1652 int error; 1653 struct tmpfs_node *node; 1654 1655 MPASS(VOP_ISLOCKED(vp)); 1656 1657 node = VP_TO_TMPFS_NODE(vp); 1658 1659 /* Disallow this operation if the file system is mounted read-only. */ 1660 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1661 return EROFS; 1662 1663 /* Immutable or append-only files cannot be modified, either. */ 1664 if (node->tn_flags & (IMMUTABLE | APPEND)) 1665 return EPERM; 1666 1667 /* Determine if the user have proper privilege to update time. */ 1668 if (vaflags & VA_UTIMES_NULL) { 1669 error = VOP_ACCESS(vp, VADMIN, cred, l); 1670 if (error) 1671 error = VOP_ACCESS(vp, VWRITE, cred, l); 1672 } else 1673 error = VOP_ACCESS(vp, VADMIN, cred, l); 1674 if (error) 1675 return (error); 1676 1677 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL) 1678 node->tn_status |= TMPFS_NODE_ACCESSED; 1679 1680 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) 1681 node->tn_status |= TMPFS_NODE_MODIFIED; 1682 1683 if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL) 1684 node->tn_status |= TMPFS_NODE_MODIFIED; 1685 1686 tmpfs_itimes(vp, atime, mtime); 1687 1688 if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL) 1689 node->tn_birthtime = *birthtime; 1690 MPASS(VOP_ISLOCKED(vp)); 1691 1692 return 0; 1693 } 1694 1695 /* --------------------------------------------------------------------- */ 1696 /* Sync timestamps */ 1697 void 1698 tmpfs_itimes(struct vnode *vp, const struct timespec *acc, 1699 const struct timespec *mod) 1700 { 1701 struct tmpfs_node *node; 1702 struct timespec now; 1703 1704 node = VP_TO_TMPFS_NODE(vp); 1705 1706 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1707 TMPFS_NODE_CHANGED)) == 0) 1708 return; 1709 1710 vfs_timestamp(&now); 1711 if (node->tn_status & TMPFS_NODE_ACCESSED) { 1712 if (acc == NULL) 1713 acc = &now; 1714 node->tn_atime = *acc; 1715 } 1716 if (node->tn_status & TMPFS_NODE_MODIFIED) { 1717 if (mod == NULL) 1718 mod = &now; 1719 node->tn_mtime = *mod; 1720 } 1721 if (node->tn_status & TMPFS_NODE_CHANGED) { 1722 node->tn_ctime = now; 1723 } 1724 node->tn_status &= 1725 ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); 1726 } 1727 1728 /* --------------------------------------------------------------------- */ 1729 1730 void 1731 tmpfs_update(struct vnode *vp) 1732 { 1733 1734 tmpfs_itimes(vp, NULL, NULL); 1735 } 1736 1737 /* --------------------------------------------------------------------- */ 1738 1739 int 1740 tmpfs_truncate(struct vnode *vp, off_t length) 1741 { 1742 int error; 1743 struct tmpfs_node *node; 1744 1745 node = VP_TO_TMPFS_NODE(vp); 1746 1747 if (length < 0) { 1748 error = EINVAL; 1749 goto out; 1750 } 1751 1752 if (node->tn_size == length) { 1753 error = 0; 1754 goto out; 1755 } 1756 1757 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) 1758 return (EFBIG); 1759 1760 error = tmpfs_reg_resize(vp, length, FALSE); 1761 if (error == 0) { 1762 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; 1763 } 1764 1765 out: 1766 tmpfs_update(vp); 1767 1768 return error; 1769 } 1770 1771 static __inline int 1772 tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b) 1773 { 1774 if (a->td_hash > b->td_hash) 1775 return (1); 1776 else if (a->td_hash < b->td_hash) 1777 return (-1); 1778 return (0); 1779 } 1780 1781 RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); 1782