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 + vm_cnt.v_free_count + vm_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 * Allocates a new node of type 'type' inside the 'tmp' mount point, with 141 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', 142 * using the credentials of the process 'p'. 143 * 144 * If the node type is set to 'VDIR', then the parent parameter must point 145 * to the parent directory of the node being created. It may only be NULL 146 * while allocating the root node. 147 * 148 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter 149 * specifies the device the node represents. 150 * 151 * If the node type is set to 'VLNK', then the parameter target specifies 152 * the file name of the target file for the symbolic link that is being 153 * created. 154 * 155 * Note that new nodes are retrieved from the available list if it has 156 * items or, if it is empty, from the node pool as long as there is enough 157 * space to create them. 158 * 159 * Returns zero on success or an appropriate error code on failure. 160 */ 161 int 162 tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type, 163 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, 164 char *target, dev_t rdev, struct tmpfs_node **node) 165 { 166 struct tmpfs_node *nnode; 167 vm_object_t obj; 168 169 /* If the root directory of the 'tmp' file system is not yet 170 * allocated, this must be the request to do it. */ 171 MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); 172 KASSERT(tmp->tm_root == NULL || mp->mnt_writeopcount > 0, 173 ("creating node not under vn_start_write")); 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 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 184 /* 185 * When a new tmpfs node is created for fully 186 * constructed mount point, there must be a parent 187 * node, which vnode is locked exclusively. As 188 * consequence, if the unmount is executing in 189 * parallel, vflush() cannot reclaim the parent vnode. 190 * Due to this, the check for MNTK_UNMOUNT flag is not 191 * racy: if we did not see MNTK_UNMOUNT flag, then tmp 192 * cannot be destroyed until node construction is 193 * finished and the parent vnode unlocked. 194 * 195 * Tmpfs does not need to instantiate new nodes during 196 * unmount. 197 */ 198 return (EBUSY); 199 } 200 201 nnode = (struct tmpfs_node *)uma_zalloc_arg( 202 tmp->tm_node_pool, tmp, M_WAITOK); 203 204 /* Generic initialization. */ 205 nnode->tn_type = type; 206 vfs_timestamp(&nnode->tn_atime); 207 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = 208 nnode->tn_atime; 209 nnode->tn_uid = uid; 210 nnode->tn_gid = gid; 211 nnode->tn_mode = mode; 212 nnode->tn_id = alloc_unr(tmp->tm_ino_unr); 213 214 /* Type-specific initialization. */ 215 switch (nnode->tn_type) { 216 case VBLK: 217 case VCHR: 218 nnode->tn_rdev = rdev; 219 break; 220 221 case VDIR: 222 RB_INIT(&nnode->tn_dir.tn_dirhead); 223 LIST_INIT(&nnode->tn_dir.tn_dupindex); 224 MPASS(parent != nnode); 225 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL)); 226 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent; 227 nnode->tn_dir.tn_readdir_lastn = 0; 228 nnode->tn_dir.tn_readdir_lastp = NULL; 229 nnode->tn_links++; 230 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent); 231 nnode->tn_dir.tn_parent->tn_links++; 232 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent); 233 break; 234 235 case VFIFO: 236 /* FALLTHROUGH */ 237 case VSOCK: 238 break; 239 240 case VLNK: 241 MPASS(strlen(target) < MAXPATHLEN); 242 nnode->tn_size = strlen(target); 243 nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME, 244 M_WAITOK); 245 memcpy(nnode->tn_link, target, nnode->tn_size); 246 break; 247 248 case VREG: 249 obj = nnode->tn_reg.tn_aobj = 250 vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0, 251 NULL /* XXXKIB - tmpfs needs swap reservation */); 252 VM_OBJECT_WLOCK(obj); 253 /* OBJ_TMPFS is set together with the setting of vp->v_object */ 254 vm_object_set_flag(obj, OBJ_NOSPLIT | OBJ_TMPFS_NODE); 255 vm_object_clear_flag(obj, OBJ_ONEMAPPING); 256 VM_OBJECT_WUNLOCK(obj); 257 break; 258 259 default: 260 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); 261 } 262 263 TMPFS_LOCK(tmp); 264 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); 265 tmp->tm_nodes_inuse++; 266 TMPFS_UNLOCK(tmp); 267 268 *node = nnode; 269 return 0; 270 } 271 272 /* 273 * Destroys the node pointed to by node from the file system 'tmp'. 274 * If the node does not belong to the given mount point, the results are 275 * unpredicted. 276 * 277 * If the node references a directory; no entries are allowed because 278 * their removal could need a recursive algorithm, something forbidden in 279 * kernel space. Furthermore, there is not need to provide such 280 * functionality (recursive removal) because the only primitives offered 281 * to the user are the removal of empty directories and the deletion of 282 * individual files. 283 * 284 * Note that nodes are not really deleted; in fact, when a node has been 285 * allocated, it cannot be deleted during the whole life of the file 286 * system. Instead, they are moved to the available list and remain there 287 * until reused. 288 */ 289 void 290 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) 291 { 292 vm_object_t uobj; 293 294 #ifdef INVARIANTS 295 TMPFS_NODE_LOCK(node); 296 MPASS(node->tn_vnode == NULL); 297 MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0); 298 TMPFS_NODE_UNLOCK(node); 299 #endif 300 301 TMPFS_LOCK(tmp); 302 LIST_REMOVE(node, tn_entries); 303 tmp->tm_nodes_inuse--; 304 TMPFS_UNLOCK(tmp); 305 306 switch (node->tn_type) { 307 case VNON: 308 /* Do not do anything. VNON is provided to let the 309 * allocation routine clean itself easily by avoiding 310 * duplicating code in it. */ 311 /* FALLTHROUGH */ 312 case VBLK: 313 /* FALLTHROUGH */ 314 case VCHR: 315 /* FALLTHROUGH */ 316 case VDIR: 317 /* FALLTHROUGH */ 318 case VFIFO: 319 /* FALLTHROUGH */ 320 case VSOCK: 321 break; 322 323 case VLNK: 324 free(node->tn_link, M_TMPFSNAME); 325 break; 326 327 case VREG: 328 uobj = node->tn_reg.tn_aobj; 329 if (uobj != NULL) { 330 TMPFS_LOCK(tmp); 331 tmp->tm_pages_used -= uobj->size; 332 TMPFS_UNLOCK(tmp); 333 KASSERT((uobj->flags & OBJ_TMPFS) == 0, 334 ("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj)); 335 vm_object_deallocate(uobj); 336 } 337 break; 338 339 default: 340 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); 341 } 342 343 free_unr(tmp->tm_ino_unr, node->tn_id); 344 uma_zfree(tmp->tm_node_pool, node); 345 } 346 347 static __inline uint32_t 348 tmpfs_dirent_hash(const char *name, u_int len) 349 { 350 uint32_t hash; 351 352 hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK; 353 #ifdef TMPFS_DEBUG_DIRCOOKIE_DUP 354 hash &= 0xf; 355 #endif 356 if (hash < TMPFS_DIRCOOKIE_MIN) 357 hash += TMPFS_DIRCOOKIE_MIN; 358 359 return (hash); 360 } 361 362 static __inline off_t 363 tmpfs_dirent_cookie(struct tmpfs_dirent *de) 364 { 365 if (de == NULL) 366 return (TMPFS_DIRCOOKIE_EOF); 367 368 MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN); 369 370 return (de->td_cookie); 371 } 372 373 static __inline boolean_t 374 tmpfs_dirent_dup(struct tmpfs_dirent *de) 375 { 376 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0); 377 } 378 379 static __inline boolean_t 380 tmpfs_dirent_duphead(struct tmpfs_dirent *de) 381 { 382 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0); 383 } 384 385 void 386 tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen) 387 { 388 de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen); 389 memcpy(de->ud.td_name, name, namelen); 390 de->td_namelen = namelen; 391 } 392 393 /* 394 * Allocates a new directory entry for the node node with a name of name. 395 * The new directory entry is returned in *de. 396 * 397 * The link count of node is increased by one to reflect the new object 398 * referencing it. 399 * 400 * Returns zero on success or an appropriate error code on failure. 401 */ 402 int 403 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 404 const char *name, u_int len, struct tmpfs_dirent **de) 405 { 406 struct tmpfs_dirent *nde; 407 408 nde = uma_zalloc(tmp->tm_dirent_pool, M_WAITOK); 409 nde->td_node = node; 410 if (name != NULL) { 411 nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK); 412 tmpfs_dirent_init(nde, name, len); 413 } else 414 nde->td_namelen = 0; 415 if (node != NULL) 416 node->tn_links++; 417 418 *de = nde; 419 420 return 0; 421 } 422 423 /* 424 * Frees a directory entry. It is the caller's responsibility to destroy 425 * the node referenced by it if needed. 426 * 427 * The link count of node is decreased by one to reflect the removal of an 428 * object that referenced it. This only happens if 'node_exists' is true; 429 * otherwise the function will not access the node referred to by the 430 * directory entry, as it may already have been released from the outside. 431 */ 432 void 433 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de) 434 { 435 struct tmpfs_node *node; 436 437 node = de->td_node; 438 if (node != NULL) { 439 MPASS(node->tn_links > 0); 440 node->tn_links--; 441 } 442 if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL) 443 free(de->ud.td_name, M_TMPFSNAME); 444 uma_zfree(tmp->tm_dirent_pool, de); 445 } 446 447 void 448 tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj) 449 { 450 451 ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject"); 452 if (vp->v_type != VREG || obj == NULL) 453 return; 454 455 VM_OBJECT_WLOCK(obj); 456 VI_LOCK(vp); 457 vm_object_clear_flag(obj, OBJ_TMPFS); 458 obj->un_pager.swp.swp_tmpfs = NULL; 459 VI_UNLOCK(vp); 460 VM_OBJECT_WUNLOCK(obj); 461 } 462 463 /* 464 * Need to clear v_object for insmntque failure. 465 */ 466 static void 467 tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg) 468 { 469 470 tmpfs_destroy_vobject(vp, vp->v_object); 471 vp->v_object = NULL; 472 vp->v_data = NULL; 473 vp->v_op = &dead_vnodeops; 474 vgone(vp); 475 vput(vp); 476 } 477 478 /* 479 * Allocates a new vnode for the node node or returns a new reference to 480 * an existing one if the node had already a vnode referencing it. The 481 * resulting locked vnode is returned in *vpp. 482 * 483 * Returns zero on success or an appropriate error code on failure. 484 */ 485 int 486 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag, 487 struct vnode **vpp) 488 { 489 struct vnode *vp; 490 vm_object_t object; 491 int error; 492 493 error = 0; 494 loop: 495 TMPFS_NODE_LOCK(node); 496 loop1: 497 if ((vp = node->tn_vnode) != NULL) { 498 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); 499 VI_LOCK(vp); 500 if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) || 501 ((vp->v_iflag & VI_DOOMED) != 0 && 502 (lkflag & LK_NOWAIT) != 0)) { 503 VI_UNLOCK(vp); 504 TMPFS_NODE_UNLOCK(node); 505 error = ENOENT; 506 vp = NULL; 507 goto out; 508 } 509 if ((vp->v_iflag & VI_DOOMED) != 0) { 510 VI_UNLOCK(vp); 511 node->tn_vpstate |= TMPFS_VNODE_WRECLAIM; 512 while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) { 513 msleep(&node->tn_vnode, TMPFS_NODE_MTX(node), 514 0, "tmpfsE", 0); 515 } 516 goto loop1; 517 } 518 TMPFS_NODE_UNLOCK(node); 519 error = vget(vp, lkflag | LK_INTERLOCK, curthread); 520 if (error == ENOENT) 521 goto loop; 522 if (error != 0) { 523 vp = NULL; 524 goto out; 525 } 526 527 /* 528 * Make sure the vnode is still there after 529 * getting the interlock to avoid racing a free. 530 */ 531 if (node->tn_vnode == NULL || node->tn_vnode != vp) { 532 vput(vp); 533 goto loop; 534 } 535 536 goto out; 537 } 538 539 if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) || 540 (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) { 541 TMPFS_NODE_UNLOCK(node); 542 error = ENOENT; 543 vp = NULL; 544 goto out; 545 } 546 547 /* 548 * otherwise lock the vp list while we call getnewvnode 549 * since that can block. 550 */ 551 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) { 552 node->tn_vpstate |= TMPFS_VNODE_WANT; 553 error = msleep((caddr_t) &node->tn_vpstate, 554 TMPFS_NODE_MTX(node), PDROP | PCATCH, 555 "tmpfs_alloc_vp", 0); 556 if (error) 557 return error; 558 559 goto loop; 560 } else 561 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING; 562 563 TMPFS_NODE_UNLOCK(node); 564 565 /* Get a new vnode and associate it with our node. */ 566 error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp); 567 if (error != 0) 568 goto unlock; 569 MPASS(vp != NULL); 570 571 /* lkflag is ignored, the lock is exclusive */ 572 (void) vn_lock(vp, lkflag | LK_RETRY); 573 574 vp->v_data = node; 575 vp->v_type = node->tn_type; 576 577 /* Type-specific initialization. */ 578 switch (node->tn_type) { 579 case VBLK: 580 /* FALLTHROUGH */ 581 case VCHR: 582 /* FALLTHROUGH */ 583 case VLNK: 584 /* FALLTHROUGH */ 585 case VSOCK: 586 break; 587 case VFIFO: 588 vp->v_op = &tmpfs_fifoop_entries; 589 break; 590 case VREG: 591 object = node->tn_reg.tn_aobj; 592 VM_OBJECT_WLOCK(object); 593 VI_LOCK(vp); 594 KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs")); 595 vp->v_object = object; 596 object->un_pager.swp.swp_tmpfs = vp; 597 vm_object_set_flag(object, OBJ_TMPFS); 598 VI_UNLOCK(vp); 599 VM_OBJECT_WUNLOCK(object); 600 break; 601 case VDIR: 602 MPASS(node->tn_dir.tn_parent != NULL); 603 if (node->tn_dir.tn_parent == node) 604 vp->v_vflag |= VV_ROOT; 605 break; 606 607 default: 608 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); 609 } 610 if (vp->v_type != VFIFO) 611 VN_LOCK_ASHARE(vp); 612 613 error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL); 614 if (error) 615 vp = NULL; 616 617 unlock: 618 TMPFS_NODE_LOCK(node); 619 620 MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING); 621 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING; 622 node->tn_vnode = vp; 623 624 if (node->tn_vpstate & TMPFS_VNODE_WANT) { 625 node->tn_vpstate &= ~TMPFS_VNODE_WANT; 626 TMPFS_NODE_UNLOCK(node); 627 wakeup((caddr_t) &node->tn_vpstate); 628 } else 629 TMPFS_NODE_UNLOCK(node); 630 631 out: 632 *vpp = vp; 633 634 #ifdef INVARIANTS 635 if (error == 0) { 636 MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp)); 637 TMPFS_NODE_LOCK(node); 638 MPASS(*vpp == node->tn_vnode); 639 TMPFS_NODE_UNLOCK(node); 640 } 641 #endif 642 643 return error; 644 } 645 646 /* 647 * Destroys the association between the vnode vp and the node it 648 * references. 649 */ 650 void 651 tmpfs_free_vp(struct vnode *vp) 652 { 653 struct tmpfs_node *node; 654 655 node = VP_TO_TMPFS_NODE(vp); 656 657 TMPFS_NODE_ASSERT_LOCKED(node); 658 node->tn_vnode = NULL; 659 if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) 660 wakeup(&node->tn_vnode); 661 node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM; 662 vp->v_data = NULL; 663 } 664 665 /* 666 * Allocates a new file of type 'type' and adds it to the parent directory 667 * 'dvp'; this addition is done using the component name given in 'cnp'. 668 * The ownership of the new file is automatically assigned based on the 669 * credentials of the caller (through 'cnp'), the group is set based on 670 * the parent directory and the mode is determined from the 'vap' argument. 671 * If successful, *vpp holds a vnode to the newly created file and zero 672 * is returned. Otherwise *vpp is NULL and the function returns an 673 * appropriate error code. 674 */ 675 int 676 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 677 struct componentname *cnp, char *target) 678 { 679 int error; 680 struct tmpfs_dirent *de; 681 struct tmpfs_mount *tmp; 682 struct tmpfs_node *dnode; 683 struct tmpfs_node *node; 684 struct tmpfs_node *parent; 685 686 MPASS(VOP_ISLOCKED(dvp)); 687 MPASS(cnp->cn_flags & HASBUF); 688 689 tmp = VFS_TO_TMPFS(dvp->v_mount); 690 dnode = VP_TO_TMPFS_DIR(dvp); 691 *vpp = NULL; 692 693 /* If the entry we are creating is a directory, we cannot overflow 694 * the number of links of its parent, because it will get a new 695 * link. */ 696 if (vap->va_type == VDIR) { 697 /* Ensure that we do not overflow the maximum number of links 698 * imposed by the system. */ 699 MPASS(dnode->tn_links <= LINK_MAX); 700 if (dnode->tn_links == LINK_MAX) { 701 return (EMLINK); 702 } 703 704 parent = dnode; 705 MPASS(parent != NULL); 706 } else 707 parent = NULL; 708 709 /* Allocate a node that represents the new file. */ 710 error = tmpfs_alloc_node(dvp->v_mount, tmp, vap->va_type, 711 cnp->cn_cred->cr_uid, 712 dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node); 713 if (error != 0) 714 return (error); 715 716 /* Allocate a directory entry that points to the new file. */ 717 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, 718 &de); 719 if (error != 0) { 720 tmpfs_free_node(tmp, node); 721 return (error); 722 } 723 724 /* Allocate a vnode for the new file. */ 725 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp); 726 if (error != 0) { 727 tmpfs_free_dirent(tmp, de); 728 tmpfs_free_node(tmp, node); 729 return (error); 730 } 731 732 /* Now that all required items are allocated, we can proceed to 733 * insert the new node into the directory, an operation that 734 * cannot fail. */ 735 if (cnp->cn_flags & ISWHITEOUT) 736 tmpfs_dir_whiteout_remove(dvp, cnp); 737 tmpfs_dir_attach(dvp, de); 738 return (0); 739 } 740 741 static struct tmpfs_dirent * 742 tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) 743 { 744 struct tmpfs_dirent *de; 745 746 de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead); 747 dc->tdc_tree = de; 748 if (de != NULL && tmpfs_dirent_duphead(de)) 749 de = LIST_FIRST(&de->ud.td_duphead); 750 dc->tdc_current = de; 751 752 return (dc->tdc_current); 753 } 754 755 static struct tmpfs_dirent * 756 tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) 757 { 758 struct tmpfs_dirent *de; 759 760 MPASS(dc->tdc_tree != NULL); 761 if (tmpfs_dirent_dup(dc->tdc_current)) { 762 dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries); 763 if (dc->tdc_current != NULL) 764 return (dc->tdc_current); 765 } 766 dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir, 767 &dnode->tn_dir.tn_dirhead, dc->tdc_tree); 768 if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) { 769 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); 770 MPASS(dc->tdc_current != NULL); 771 } 772 773 return (dc->tdc_current); 774 } 775 776 /* Lookup directory entry in RB-Tree. Function may return duphead entry. */ 777 static struct tmpfs_dirent * 778 tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash) 779 { 780 struct tmpfs_dirent *de, dekey; 781 782 dekey.td_hash = hash; 783 de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey); 784 return (de); 785 } 786 787 /* Lookup directory entry by cookie, initialize directory cursor accordingly. */ 788 static struct tmpfs_dirent * 789 tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie, 790 struct tmpfs_dir_cursor *dc) 791 { 792 struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead; 793 struct tmpfs_dirent *de, dekey; 794 795 MPASS(cookie >= TMPFS_DIRCOOKIE_MIN); 796 797 if (cookie == node->tn_dir.tn_readdir_lastn && 798 (de = node->tn_dir.tn_readdir_lastp) != NULL) { 799 /* Protect against possible race, tn_readdir_last[pn] 800 * may be updated with only shared vnode lock held. */ 801 if (cookie == tmpfs_dirent_cookie(de)) 802 goto out; 803 } 804 805 if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) { 806 LIST_FOREACH(de, &node->tn_dir.tn_dupindex, 807 uh.td_dup.index_entries) { 808 MPASS(tmpfs_dirent_dup(de)); 809 if (de->td_cookie == cookie) 810 goto out; 811 /* dupindex list is sorted. */ 812 if (de->td_cookie < cookie) { 813 de = NULL; 814 goto out; 815 } 816 } 817 MPASS(de == NULL); 818 goto out; 819 } 820 821 MPASS((cookie & TMPFS_DIRCOOKIE_MASK) == cookie); 822 dekey.td_hash = cookie; 823 /* Recover if direntry for cookie was removed */ 824 de = RB_NFIND(tmpfs_dir, dirhead, &dekey); 825 dc->tdc_tree = de; 826 dc->tdc_current = de; 827 if (de != NULL && tmpfs_dirent_duphead(de)) { 828 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); 829 MPASS(dc->tdc_current != NULL); 830 } 831 return (dc->tdc_current); 832 833 out: 834 dc->tdc_tree = de; 835 dc->tdc_current = de; 836 if (de != NULL && tmpfs_dirent_dup(de)) 837 dc->tdc_tree = tmpfs_dir_xlookup_hash(node, 838 de->td_hash); 839 return (dc->tdc_current); 840 } 841 842 /* 843 * Looks for a directory entry in the directory represented by node. 844 * 'cnp' describes the name of the entry to look for. Note that the . 845 * and .. components are not allowed as they do not physically exist 846 * within directories. 847 * 848 * Returns a pointer to the entry when found, otherwise NULL. 849 */ 850 struct tmpfs_dirent * 851 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, 852 struct componentname *cnp) 853 { 854 struct tmpfs_dir_duphead *duphead; 855 struct tmpfs_dirent *de; 856 uint32_t hash; 857 858 MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); 859 MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && 860 cnp->cn_nameptr[1] == '.'))); 861 TMPFS_VALIDATE_DIR(node); 862 863 hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen); 864 de = tmpfs_dir_xlookup_hash(node, hash); 865 if (de != NULL && tmpfs_dirent_duphead(de)) { 866 duphead = &de->ud.td_duphead; 867 LIST_FOREACH(de, duphead, uh.td_dup.entries) { 868 if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, 869 cnp->cn_namelen)) 870 break; 871 } 872 } else if (de != NULL) { 873 if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, 874 cnp->cn_namelen)) 875 de = NULL; 876 } 877 if (de != NULL && f != NULL && de->td_node != f) 878 de = NULL; 879 880 return (de); 881 } 882 883 /* 884 * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex 885 * list, allocate new cookie value. 886 */ 887 static void 888 tmpfs_dir_attach_dup(struct tmpfs_node *dnode, 889 struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde) 890 { 891 struct tmpfs_dir_duphead *dupindex; 892 struct tmpfs_dirent *de, *pde; 893 894 dupindex = &dnode->tn_dir.tn_dupindex; 895 de = LIST_FIRST(dupindex); 896 if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) { 897 if (de == NULL) 898 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; 899 else 900 nde->td_cookie = de->td_cookie + 1; 901 MPASS(tmpfs_dirent_dup(nde)); 902 LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries); 903 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 904 return; 905 } 906 907 /* 908 * Cookie numbers are near exhaustion. Scan dupindex list for unused 909 * numbers. dupindex list is sorted in descending order. Keep it so 910 * after inserting nde. 911 */ 912 while (1) { 913 pde = de; 914 de = LIST_NEXT(de, uh.td_dup.index_entries); 915 if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) { 916 /* 917 * Last element of the index doesn't have minimal cookie 918 * value, use it. 919 */ 920 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; 921 LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries); 922 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 923 return; 924 } else if (de == NULL) { 925 /* 926 * We are so lucky have 2^30 hash duplicates in single 927 * directory :) Return largest possible cookie value. 928 * It should be fine except possible issues with 929 * VOP_READDIR restart. 930 */ 931 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX; 932 LIST_INSERT_HEAD(dupindex, nde, 933 uh.td_dup.index_entries); 934 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 935 return; 936 } 937 if (de->td_cookie + 1 == pde->td_cookie || 938 de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX) 939 continue; /* No hole or invalid cookie. */ 940 nde->td_cookie = de->td_cookie + 1; 941 MPASS(tmpfs_dirent_dup(nde)); 942 MPASS(pde->td_cookie > nde->td_cookie); 943 MPASS(nde->td_cookie > de->td_cookie); 944 LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries); 945 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 946 return; 947 }; 948 } 949 950 /* 951 * Attaches the directory entry de to the directory represented by vp. 952 * Note that this does not change the link count of the node pointed by 953 * the directory entry, as this is done by tmpfs_alloc_dirent. 954 */ 955 void 956 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) 957 { 958 struct tmpfs_node *dnode; 959 struct tmpfs_dirent *xde, *nde; 960 961 ASSERT_VOP_ELOCKED(vp, __func__); 962 MPASS(de->td_namelen > 0); 963 MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN); 964 MPASS(de->td_cookie == de->td_hash); 965 966 dnode = VP_TO_TMPFS_DIR(vp); 967 dnode->tn_dir.tn_readdir_lastn = 0; 968 dnode->tn_dir.tn_readdir_lastp = NULL; 969 970 MPASS(!tmpfs_dirent_dup(de)); 971 xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); 972 if (xde != NULL && tmpfs_dirent_duphead(xde)) 973 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); 974 else if (xde != NULL) { 975 /* 976 * Allocate new duphead. Swap xde with duphead to avoid 977 * adding/removing elements with the same hash. 978 */ 979 MPASS(!tmpfs_dirent_dup(xde)); 980 tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0, 981 &nde); 982 /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */ 983 memcpy(nde, xde, sizeof(*xde)); 984 xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD; 985 LIST_INIT(&xde->ud.td_duphead); 986 xde->td_namelen = 0; 987 xde->td_node = NULL; 988 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde); 989 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); 990 } 991 dnode->tn_size += sizeof(struct tmpfs_dirent); 992 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 993 TMPFS_NODE_MODIFIED; 994 } 995 996 /* 997 * Detaches the directory entry de from the directory represented by vp. 998 * Note that this does not change the link count of the node pointed by 999 * the directory entry, as this is done by tmpfs_free_dirent. 1000 */ 1001 void 1002 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) 1003 { 1004 struct tmpfs_mount *tmp; 1005 struct tmpfs_dir *head; 1006 struct tmpfs_node *dnode; 1007 struct tmpfs_dirent *xde; 1008 1009 ASSERT_VOP_ELOCKED(vp, __func__); 1010 1011 dnode = VP_TO_TMPFS_DIR(vp); 1012 head = &dnode->tn_dir.tn_dirhead; 1013 dnode->tn_dir.tn_readdir_lastn = 0; 1014 dnode->tn_dir.tn_readdir_lastp = NULL; 1015 1016 if (tmpfs_dirent_dup(de)) { 1017 /* Remove duphead if de was last entry. */ 1018 if (LIST_NEXT(de, uh.td_dup.entries) == NULL) { 1019 xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash); 1020 MPASS(tmpfs_dirent_duphead(xde)); 1021 } else 1022 xde = NULL; 1023 LIST_REMOVE(de, uh.td_dup.entries); 1024 LIST_REMOVE(de, uh.td_dup.index_entries); 1025 if (xde != NULL) { 1026 if (LIST_EMPTY(&xde->ud.td_duphead)) { 1027 RB_REMOVE(tmpfs_dir, head, xde); 1028 tmp = VFS_TO_TMPFS(vp->v_mount); 1029 MPASS(xde->td_node == NULL); 1030 tmpfs_free_dirent(tmp, xde); 1031 } 1032 } 1033 } else 1034 RB_REMOVE(tmpfs_dir, head, de); 1035 1036 dnode->tn_size -= sizeof(struct tmpfs_dirent); 1037 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 1038 TMPFS_NODE_MODIFIED; 1039 } 1040 1041 void 1042 tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode) 1043 { 1044 struct tmpfs_dirent *de, *dde, *nde; 1045 1046 RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) { 1047 RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); 1048 /* Node may already be destroyed. */ 1049 de->td_node = NULL; 1050 if (tmpfs_dirent_duphead(de)) { 1051 while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) { 1052 LIST_REMOVE(dde, uh.td_dup.entries); 1053 dde->td_node = NULL; 1054 tmpfs_free_dirent(tmp, dde); 1055 } 1056 } 1057 tmpfs_free_dirent(tmp, de); 1058 } 1059 } 1060 1061 /* 1062 * Helper function for tmpfs_readdir. Creates a '.' entry for the given 1063 * directory and returns it in the uio space. The function returns 0 1064 * on success, -1 if there was not enough space in the uio structure to 1065 * hold the directory entry or an appropriate error code if another 1066 * error happens. 1067 */ 1068 static int 1069 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) 1070 { 1071 int error; 1072 struct dirent dent; 1073 1074 TMPFS_VALIDATE_DIR(node); 1075 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); 1076 1077 dent.d_fileno = node->tn_id; 1078 dent.d_type = DT_DIR; 1079 dent.d_namlen = 1; 1080 dent.d_name[0] = '.'; 1081 dent.d_name[1] = '\0'; 1082 dent.d_reclen = GENERIC_DIRSIZ(&dent); 1083 1084 if (dent.d_reclen > uio->uio_resid) 1085 error = EJUSTRETURN; 1086 else 1087 error = uiomove(&dent, dent.d_reclen, uio); 1088 1089 node->tn_status |= TMPFS_NODE_ACCESSED; 1090 1091 return error; 1092 } 1093 1094 /* 1095 * Helper function for tmpfs_readdir. Creates a '..' entry for the given 1096 * directory and returns it in the uio space. The function returns 0 1097 * on success, -1 if there was not enough space in the uio structure to 1098 * hold the directory entry or an appropriate error code if another 1099 * error happens. 1100 */ 1101 static int 1102 tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio) 1103 { 1104 int error; 1105 struct dirent dent; 1106 1107 TMPFS_VALIDATE_DIR(node); 1108 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); 1109 1110 /* 1111 * Return ENOENT if the current node is already removed. 1112 */ 1113 TMPFS_ASSERT_LOCKED(node); 1114 if (node->tn_dir.tn_parent == NULL) { 1115 return (ENOENT); 1116 } 1117 1118 TMPFS_NODE_LOCK(node->tn_dir.tn_parent); 1119 dent.d_fileno = node->tn_dir.tn_parent->tn_id; 1120 TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent); 1121 1122 dent.d_type = DT_DIR; 1123 dent.d_namlen = 2; 1124 dent.d_name[0] = '.'; 1125 dent.d_name[1] = '.'; 1126 dent.d_name[2] = '\0'; 1127 dent.d_reclen = GENERIC_DIRSIZ(&dent); 1128 1129 if (dent.d_reclen > uio->uio_resid) 1130 error = EJUSTRETURN; 1131 else 1132 error = uiomove(&dent, dent.d_reclen, uio); 1133 1134 node->tn_status |= TMPFS_NODE_ACCESSED; 1135 1136 return error; 1137 } 1138 1139 /* 1140 * Helper function for tmpfs_readdir. Returns as much directory entries 1141 * as can fit in the uio space. The read starts at uio->uio_offset. 1142 * The function returns 0 on success, -1 if there was not enough space 1143 * in the uio structure to hold the directory entry or an appropriate 1144 * error code if another error happens. 1145 */ 1146 int 1147 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, int maxcookies, 1148 u_long *cookies, int *ncookies) 1149 { 1150 struct tmpfs_dir_cursor dc; 1151 struct tmpfs_dirent *de; 1152 off_t off; 1153 int error; 1154 1155 TMPFS_VALIDATE_DIR(node); 1156 1157 off = 0; 1158 1159 /* 1160 * Lookup the node from the current offset. The starting offset of 1161 * 0 will lookup both '.' and '..', and then the first real entry, 1162 * or EOF if there are none. Then find all entries for the dir that 1163 * fit into the buffer. Once no more entries are found (de == NULL), 1164 * the offset is set to TMPFS_DIRCOOKIE_EOF, which will cause the next 1165 * call to return 0. 1166 */ 1167 switch (uio->uio_offset) { 1168 case TMPFS_DIRCOOKIE_DOT: 1169 error = tmpfs_dir_getdotdent(node, uio); 1170 if (error != 0) 1171 return (error); 1172 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 1173 if (cookies != NULL) 1174 cookies[(*ncookies)++] = off = uio->uio_offset; 1175 /* FALLTHROUGH */ 1176 case TMPFS_DIRCOOKIE_DOTDOT: 1177 error = tmpfs_dir_getdotdotdent(node, uio); 1178 if (error != 0) 1179 return (error); 1180 de = tmpfs_dir_first(node, &dc); 1181 uio->uio_offset = tmpfs_dirent_cookie(de); 1182 if (cookies != NULL) 1183 cookies[(*ncookies)++] = off = uio->uio_offset; 1184 /* EOF. */ 1185 if (de == NULL) 1186 return (0); 1187 break; 1188 case TMPFS_DIRCOOKIE_EOF: 1189 return (0); 1190 default: 1191 de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc); 1192 if (de == NULL) 1193 return (EINVAL); 1194 if (cookies != NULL) 1195 off = tmpfs_dirent_cookie(de); 1196 } 1197 1198 /* Read as much entries as possible; i.e., until we reach the end of 1199 * the directory or we exhaust uio space. */ 1200 do { 1201 struct dirent d; 1202 1203 /* Create a dirent structure representing the current 1204 * tmpfs_node and fill it. */ 1205 if (de->td_node == NULL) { 1206 d.d_fileno = 1; 1207 d.d_type = DT_WHT; 1208 } else { 1209 d.d_fileno = de->td_node->tn_id; 1210 switch (de->td_node->tn_type) { 1211 case VBLK: 1212 d.d_type = DT_BLK; 1213 break; 1214 1215 case VCHR: 1216 d.d_type = DT_CHR; 1217 break; 1218 1219 case VDIR: 1220 d.d_type = DT_DIR; 1221 break; 1222 1223 case VFIFO: 1224 d.d_type = DT_FIFO; 1225 break; 1226 1227 case VLNK: 1228 d.d_type = DT_LNK; 1229 break; 1230 1231 case VREG: 1232 d.d_type = DT_REG; 1233 break; 1234 1235 case VSOCK: 1236 d.d_type = DT_SOCK; 1237 break; 1238 1239 default: 1240 panic("tmpfs_dir_getdents: type %p %d", 1241 de->td_node, (int)de->td_node->tn_type); 1242 } 1243 } 1244 d.d_namlen = de->td_namelen; 1245 MPASS(de->td_namelen < sizeof(d.d_name)); 1246 (void)memcpy(d.d_name, de->ud.td_name, de->td_namelen); 1247 d.d_name[de->td_namelen] = '\0'; 1248 d.d_reclen = GENERIC_DIRSIZ(&d); 1249 1250 /* Stop reading if the directory entry we are treating is 1251 * bigger than the amount of data that can be returned. */ 1252 if (d.d_reclen > uio->uio_resid) { 1253 error = EJUSTRETURN; 1254 break; 1255 } 1256 1257 /* Copy the new dirent structure into the output buffer and 1258 * advance pointers. */ 1259 error = uiomove(&d, d.d_reclen, uio); 1260 if (error == 0) { 1261 de = tmpfs_dir_next(node, &dc); 1262 if (cookies != NULL) { 1263 off = tmpfs_dirent_cookie(de); 1264 MPASS(*ncookies < maxcookies); 1265 cookies[(*ncookies)++] = off; 1266 } 1267 } 1268 } while (error == 0 && uio->uio_resid > 0 && de != NULL); 1269 1270 /* Skip setting off when using cookies as it is already done above. */ 1271 if (cookies == NULL) 1272 off = tmpfs_dirent_cookie(de); 1273 1274 /* Update the offset and cache. */ 1275 uio->uio_offset = off; 1276 node->tn_dir.tn_readdir_lastn = off; 1277 node->tn_dir.tn_readdir_lastp = de; 1278 1279 node->tn_status |= TMPFS_NODE_ACCESSED; 1280 return error; 1281 } 1282 1283 int 1284 tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp) 1285 { 1286 struct tmpfs_dirent *de; 1287 int error; 1288 1289 error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL, 1290 cnp->cn_nameptr, cnp->cn_namelen, &de); 1291 if (error != 0) 1292 return (error); 1293 tmpfs_dir_attach(dvp, de); 1294 return (0); 1295 } 1296 1297 void 1298 tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) 1299 { 1300 struct tmpfs_dirent *de; 1301 1302 de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp); 1303 MPASS(de != NULL && de->td_node == NULL); 1304 tmpfs_dir_detach(dvp, de); 1305 tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de); 1306 } 1307 1308 /* 1309 * Resizes the aobj associated with the regular file pointed to by 'vp' to the 1310 * size 'newsize'. 'vp' must point to a vnode that represents a regular file. 1311 * 'newsize' must be positive. 1312 * 1313 * Returns zero on success or an appropriate error code on failure. 1314 */ 1315 int 1316 tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) 1317 { 1318 struct tmpfs_mount *tmp; 1319 struct tmpfs_node *node; 1320 vm_object_t uobj; 1321 vm_page_t m, ma[1]; 1322 vm_pindex_t idx, newpages, oldpages; 1323 off_t oldsize; 1324 int base, rv; 1325 1326 MPASS(vp->v_type == VREG); 1327 MPASS(newsize >= 0); 1328 1329 node = VP_TO_TMPFS_NODE(vp); 1330 uobj = node->tn_reg.tn_aobj; 1331 tmp = VFS_TO_TMPFS(vp->v_mount); 1332 1333 /* 1334 * Convert the old and new sizes to the number of pages needed to 1335 * store them. It may happen that we do not need to do anything 1336 * because the last allocated page can accommodate the change on 1337 * its own. 1338 */ 1339 oldsize = node->tn_size; 1340 oldpages = OFF_TO_IDX(oldsize + PAGE_MASK); 1341 MPASS(oldpages == uobj->size); 1342 newpages = OFF_TO_IDX(newsize + PAGE_MASK); 1343 if (newpages > oldpages && 1344 tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0) 1345 return (ENOSPC); 1346 1347 VM_OBJECT_WLOCK(uobj); 1348 if (newsize < oldsize) { 1349 /* 1350 * Zero the truncated part of the last page. 1351 */ 1352 base = newsize & PAGE_MASK; 1353 if (base != 0) { 1354 idx = OFF_TO_IDX(newsize); 1355 retry: 1356 m = vm_page_lookup(uobj, idx); 1357 if (m != NULL) { 1358 if (vm_page_sleep_if_busy(m, "tmfssz")) 1359 goto retry; 1360 MPASS(m->valid == VM_PAGE_BITS_ALL); 1361 } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { 1362 m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL); 1363 if (m == NULL) { 1364 VM_OBJECT_WUNLOCK(uobj); 1365 VM_WAIT; 1366 VM_OBJECT_WLOCK(uobj); 1367 goto retry; 1368 } else if (m->valid != VM_PAGE_BITS_ALL) { 1369 ma[0] = m; 1370 rv = vm_pager_get_pages(uobj, ma, 1, 0); 1371 m = vm_page_lookup(uobj, idx); 1372 } else 1373 /* A cached page was reactivated. */ 1374 rv = VM_PAGER_OK; 1375 vm_page_lock(m); 1376 if (rv == VM_PAGER_OK) { 1377 vm_page_deactivate(m); 1378 vm_page_unlock(m); 1379 vm_page_xunbusy(m); 1380 } else { 1381 vm_page_free(m); 1382 vm_page_unlock(m); 1383 if (ignerr) 1384 m = NULL; 1385 else { 1386 VM_OBJECT_WUNLOCK(uobj); 1387 return (EIO); 1388 } 1389 } 1390 } 1391 if (m != NULL) { 1392 pmap_zero_page_area(m, base, PAGE_SIZE - base); 1393 vm_page_dirty(m); 1394 vm_pager_page_unswapped(m); 1395 } 1396 } 1397 1398 /* 1399 * Release any swap space and free any whole pages. 1400 */ 1401 if (newpages < oldpages) { 1402 swap_pager_freespace(uobj, newpages, oldpages - 1403 newpages); 1404 vm_object_page_remove(uobj, newpages, 0, 0); 1405 } 1406 } 1407 uobj->size = newpages; 1408 VM_OBJECT_WUNLOCK(uobj); 1409 1410 TMPFS_LOCK(tmp); 1411 tmp->tm_pages_used += (newpages - oldpages); 1412 TMPFS_UNLOCK(tmp); 1413 1414 node->tn_size = newsize; 1415 return (0); 1416 } 1417 1418 /* 1419 * Change flags of the given vnode. 1420 * Caller should execute tmpfs_update on vp after a successful execution. 1421 * The vnode must be locked on entry and remain locked on exit. 1422 */ 1423 int 1424 tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred, 1425 struct thread *p) 1426 { 1427 int error; 1428 struct tmpfs_node *node; 1429 1430 MPASS(VOP_ISLOCKED(vp)); 1431 1432 node = VP_TO_TMPFS_NODE(vp); 1433 1434 if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK | 1435 UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP | 1436 UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE | 1437 UF_SPARSE | UF_SYSTEM)) != 0) 1438 return (EOPNOTSUPP); 1439 1440 /* Disallow this operation if the file system is mounted read-only. */ 1441 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1442 return EROFS; 1443 1444 /* 1445 * Callers may only modify the file flags on objects they 1446 * have VADMIN rights for. 1447 */ 1448 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1449 return (error); 1450 /* 1451 * Unprivileged processes are not permitted to unset system 1452 * flags, or modify flags if any system flags are set. 1453 */ 1454 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) { 1455 if (node->tn_flags & 1456 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) { 1457 error = securelevel_gt(cred, 0); 1458 if (error) 1459 return (error); 1460 } 1461 } else { 1462 if (node->tn_flags & 1463 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || 1464 ((flags ^ node->tn_flags) & SF_SETTABLE)) 1465 return (EPERM); 1466 } 1467 node->tn_flags = flags; 1468 node->tn_status |= TMPFS_NODE_CHANGED; 1469 1470 MPASS(VOP_ISLOCKED(vp)); 1471 1472 return 0; 1473 } 1474 1475 /* 1476 * Change access mode on the given vnode. 1477 * Caller should execute tmpfs_update on vp after a successful execution. 1478 * The vnode must be locked on entry and remain locked on exit. 1479 */ 1480 int 1481 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p) 1482 { 1483 int error; 1484 struct tmpfs_node *node; 1485 1486 MPASS(VOP_ISLOCKED(vp)); 1487 1488 node = VP_TO_TMPFS_NODE(vp); 1489 1490 /* Disallow this operation if the file system is mounted read-only. */ 1491 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1492 return EROFS; 1493 1494 /* Immutable or append-only files cannot be modified, either. */ 1495 if (node->tn_flags & (IMMUTABLE | APPEND)) 1496 return EPERM; 1497 1498 /* 1499 * To modify the permissions on a file, must possess VADMIN 1500 * for that file. 1501 */ 1502 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1503 return (error); 1504 1505 /* 1506 * Privileged processes may set the sticky bit on non-directories, 1507 * as well as set the setgid bit on a file with a group that the 1508 * process is not a member of. 1509 */ 1510 if (vp->v_type != VDIR && (mode & S_ISTXT)) { 1511 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0)) 1512 return (EFTYPE); 1513 } 1514 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) { 1515 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0); 1516 if (error) 1517 return (error); 1518 } 1519 1520 1521 node->tn_mode &= ~ALLPERMS; 1522 node->tn_mode |= mode & ALLPERMS; 1523 1524 node->tn_status |= TMPFS_NODE_CHANGED; 1525 1526 MPASS(VOP_ISLOCKED(vp)); 1527 1528 return 0; 1529 } 1530 1531 /* 1532 * Change ownership of the given vnode. At least one of uid or gid must 1533 * be different than VNOVAL. If one is set to that value, the attribute 1534 * is unchanged. 1535 * Caller should execute tmpfs_update on vp after a successful execution. 1536 * The vnode must be locked on entry and remain locked on exit. 1537 */ 1538 int 1539 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, 1540 struct thread *p) 1541 { 1542 int error; 1543 struct tmpfs_node *node; 1544 uid_t ouid; 1545 gid_t ogid; 1546 1547 MPASS(VOP_ISLOCKED(vp)); 1548 1549 node = VP_TO_TMPFS_NODE(vp); 1550 1551 /* Assign default values if they are unknown. */ 1552 MPASS(uid != VNOVAL || gid != VNOVAL); 1553 if (uid == VNOVAL) 1554 uid = node->tn_uid; 1555 if (gid == VNOVAL) 1556 gid = node->tn_gid; 1557 MPASS(uid != VNOVAL && gid != VNOVAL); 1558 1559 /* Disallow this operation if the file system is mounted read-only. */ 1560 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1561 return EROFS; 1562 1563 /* Immutable or append-only files cannot be modified, either. */ 1564 if (node->tn_flags & (IMMUTABLE | APPEND)) 1565 return EPERM; 1566 1567 /* 1568 * To modify the ownership of a file, must possess VADMIN for that 1569 * file. 1570 */ 1571 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1572 return (error); 1573 1574 /* 1575 * To change the owner of a file, or change the group of a file to a 1576 * group of which we are not a member, the caller must have 1577 * privilege. 1578 */ 1579 if ((uid != node->tn_uid || 1580 (gid != node->tn_gid && !groupmember(gid, cred))) && 1581 (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0))) 1582 return (error); 1583 1584 ogid = node->tn_gid; 1585 ouid = node->tn_uid; 1586 1587 node->tn_uid = uid; 1588 node->tn_gid = gid; 1589 1590 node->tn_status |= TMPFS_NODE_CHANGED; 1591 1592 if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) { 1593 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0)) 1594 node->tn_mode &= ~(S_ISUID | S_ISGID); 1595 } 1596 1597 MPASS(VOP_ISLOCKED(vp)); 1598 1599 return 0; 1600 } 1601 1602 /* 1603 * Change size of the given vnode. 1604 * Caller should execute tmpfs_update on vp after a successful execution. 1605 * The vnode must be locked on entry and remain locked on exit. 1606 */ 1607 int 1608 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, 1609 struct thread *p) 1610 { 1611 int error; 1612 struct tmpfs_node *node; 1613 1614 MPASS(VOP_ISLOCKED(vp)); 1615 1616 node = VP_TO_TMPFS_NODE(vp); 1617 1618 /* Decide whether this is a valid operation based on the file type. */ 1619 error = 0; 1620 switch (vp->v_type) { 1621 case VDIR: 1622 return EISDIR; 1623 1624 case VREG: 1625 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1626 return EROFS; 1627 break; 1628 1629 case VBLK: 1630 /* FALLTHROUGH */ 1631 case VCHR: 1632 /* FALLTHROUGH */ 1633 case VFIFO: 1634 /* Allow modifications of special files even if in the file 1635 * system is mounted read-only (we are not modifying the 1636 * files themselves, but the objects they represent). */ 1637 return 0; 1638 1639 default: 1640 /* Anything else is unsupported. */ 1641 return EOPNOTSUPP; 1642 } 1643 1644 /* Immutable or append-only files cannot be modified, either. */ 1645 if (node->tn_flags & (IMMUTABLE | APPEND)) 1646 return EPERM; 1647 1648 error = tmpfs_truncate(vp, size); 1649 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents 1650 * for us, as will update tn_status; no need to do that here. */ 1651 1652 MPASS(VOP_ISLOCKED(vp)); 1653 1654 return error; 1655 } 1656 1657 /* 1658 * Change access and modification times of the given vnode. 1659 * Caller should execute tmpfs_update on vp after a successful execution. 1660 * The vnode must be locked on entry and remain locked on exit. 1661 */ 1662 int 1663 tmpfs_chtimes(struct vnode *vp, struct vattr *vap, 1664 struct ucred *cred, struct thread *l) 1665 { 1666 int error; 1667 struct tmpfs_node *node; 1668 1669 MPASS(VOP_ISLOCKED(vp)); 1670 1671 node = VP_TO_TMPFS_NODE(vp); 1672 1673 /* Disallow this operation if the file system is mounted read-only. */ 1674 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1675 return EROFS; 1676 1677 /* Immutable or append-only files cannot be modified, either. */ 1678 if (node->tn_flags & (IMMUTABLE | APPEND)) 1679 return EPERM; 1680 1681 error = vn_utimes_perm(vp, vap, cred, l); 1682 if (error != 0) 1683 return (error); 1684 1685 if (vap->va_atime.tv_sec != VNOVAL && vap->va_atime.tv_nsec != VNOVAL) 1686 node->tn_status |= TMPFS_NODE_ACCESSED; 1687 1688 if (vap->va_mtime.tv_sec != VNOVAL && vap->va_mtime.tv_nsec != VNOVAL) 1689 node->tn_status |= TMPFS_NODE_MODIFIED; 1690 1691 if (vap->va_birthtime.tv_nsec != VNOVAL && 1692 vap->va_birthtime.tv_nsec != VNOVAL) 1693 node->tn_status |= TMPFS_NODE_MODIFIED; 1694 1695 tmpfs_itimes(vp, &vap->va_atime, &vap->va_mtime); 1696 1697 if (vap->va_birthtime.tv_nsec != VNOVAL && 1698 vap->va_birthtime.tv_nsec != VNOVAL) 1699 node->tn_birthtime = vap->va_birthtime; 1700 MPASS(VOP_ISLOCKED(vp)); 1701 1702 return 0; 1703 } 1704 1705 /* Sync timestamps */ 1706 void 1707 tmpfs_itimes(struct vnode *vp, const struct timespec *acc, 1708 const struct timespec *mod) 1709 { 1710 struct tmpfs_node *node; 1711 struct timespec now; 1712 1713 node = VP_TO_TMPFS_NODE(vp); 1714 1715 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1716 TMPFS_NODE_CHANGED)) == 0) 1717 return; 1718 1719 vfs_timestamp(&now); 1720 if (node->tn_status & TMPFS_NODE_ACCESSED) { 1721 if (acc == NULL) 1722 acc = &now; 1723 node->tn_atime = *acc; 1724 } 1725 if (node->tn_status & TMPFS_NODE_MODIFIED) { 1726 if (mod == NULL) 1727 mod = &now; 1728 node->tn_mtime = *mod; 1729 } 1730 if (node->tn_status & TMPFS_NODE_CHANGED) { 1731 node->tn_ctime = now; 1732 } 1733 node->tn_status &= 1734 ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); 1735 } 1736 1737 void 1738 tmpfs_update(struct vnode *vp) 1739 { 1740 1741 tmpfs_itimes(vp, NULL, NULL); 1742 } 1743 1744 int 1745 tmpfs_truncate(struct vnode *vp, off_t length) 1746 { 1747 int error; 1748 struct tmpfs_node *node; 1749 1750 node = VP_TO_TMPFS_NODE(vp); 1751 1752 if (length < 0) { 1753 error = EINVAL; 1754 goto out; 1755 } 1756 1757 if (node->tn_size == length) { 1758 error = 0; 1759 goto out; 1760 } 1761 1762 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) 1763 return (EFBIG); 1764 1765 error = tmpfs_reg_resize(vp, length, FALSE); 1766 if (error == 0) { 1767 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; 1768 } 1769 1770 out: 1771 tmpfs_update(vp); 1772 1773 return error; 1774 } 1775 1776 static __inline int 1777 tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b) 1778 { 1779 if (a->td_hash > b->td_hash) 1780 return (1); 1781 else if (a->td_hash < b->td_hash) 1782 return (-1); 1783 return (0); 1784 } 1785 1786 RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); 1787