tmpfs_subr.c revision 327785
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: stable/11/sys/fs/tmpfs/tmpfs_subr.c 327785 2018-01-10 20:39:26Z markj $"); 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/random.h> 46#include <sys/rwlock.h> 47#include <sys/stat.h> 48#include <sys/systm.h> 49#include <sys/sysctl.h> 50#include <sys/vnode.h> 51#include <sys/vmmeter.h> 52 53#include <vm/vm.h> 54#include <vm/vm_param.h> 55#include <vm/vm_object.h> 56#include <vm/vm_page.h> 57#include <vm/vm_pageout.h> 58#include <vm/vm_pager.h> 59#include <vm/vm_extern.h> 60 61#include <fs/tmpfs/tmpfs.h> 62#include <fs/tmpfs/tmpfs_fifoops.h> 63#include <fs/tmpfs/tmpfs_vnops.h> 64 65SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW, 0, "tmpfs file system"); 66 67static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED; 68 69static int 70sysctl_mem_reserved(SYSCTL_HANDLER_ARGS) 71{ 72 int error; 73 long pages, bytes; 74 75 pages = *(long *)arg1; 76 bytes = pages * PAGE_SIZE; 77 78 error = sysctl_handle_long(oidp, &bytes, 0, req); 79 if (error || !req->newptr) 80 return (error); 81 82 pages = bytes / PAGE_SIZE; 83 if (pages < TMPFS_PAGES_MINRESERVED) 84 return (EINVAL); 85 86 *(long *)arg1 = pages; 87 return (0); 88} 89 90SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_RW, 91 &tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L", 92 "Amount of available memory and swap below which tmpfs growth stops"); 93 94static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a, 95 struct tmpfs_dirent *b); 96RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); 97 98size_t 99tmpfs_mem_avail(void) 100{ 101 vm_ooffset_t avail; 102 103 avail = swap_pager_avail + vm_cnt.v_free_count - tmpfs_pages_reserved; 104 if (__predict_false(avail < 0)) 105 avail = 0; 106 return (avail); 107} 108 109size_t 110tmpfs_pages_used(struct tmpfs_mount *tmp) 111{ 112 const size_t node_size = sizeof(struct tmpfs_node) + 113 sizeof(struct tmpfs_dirent); 114 size_t meta_pages; 115 116 meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size, 117 PAGE_SIZE); 118 return (meta_pages + tmp->tm_pages_used); 119} 120 121static size_t 122tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages) 123{ 124 if (tmpfs_mem_avail() < req_pages) 125 return (0); 126 127 if (tmp->tm_pages_max != ULONG_MAX && 128 tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp)) 129 return (0); 130 131 return (1); 132} 133 134void 135tmpfs_ref_node(struct tmpfs_node *node) 136{ 137 138 TMPFS_NODE_LOCK(node); 139 tmpfs_ref_node_locked(node); 140 TMPFS_NODE_UNLOCK(node); 141} 142 143void 144tmpfs_ref_node_locked(struct tmpfs_node *node) 145{ 146 147 TMPFS_NODE_ASSERT_LOCKED(node); 148 KASSERT(node->tn_refcount > 0, ("node %p zero refcount", node)); 149 KASSERT(node->tn_refcount < UINT_MAX, ("node %p refcount %u", node, 150 node->tn_refcount)); 151 node->tn_refcount++; 152} 153 154/* 155 * Allocates a new node of type 'type' inside the 'tmp' mount point, with 156 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', 157 * using the credentials of the process 'p'. 158 * 159 * If the node type is set to 'VDIR', then the parent parameter must point 160 * to the parent directory of the node being created. It may only be NULL 161 * while allocating the root node. 162 * 163 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter 164 * specifies the device the node represents. 165 * 166 * If the node type is set to 'VLNK', then the parameter target specifies 167 * the file name of the target file for the symbolic link that is being 168 * created. 169 * 170 * Note that new nodes are retrieved from the available list if it has 171 * items or, if it is empty, from the node pool as long as there is enough 172 * space to create them. 173 * 174 * Returns zero on success or an appropriate error code on failure. 175 */ 176int 177tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type, 178 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, 179 char *target, dev_t rdev, struct tmpfs_node **node) 180{ 181 struct tmpfs_node *nnode; 182 vm_object_t obj; 183 184 /* If the root directory of the 'tmp' file system is not yet 185 * allocated, this must be the request to do it. */ 186 MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); 187 KASSERT(tmp->tm_root == NULL || mp->mnt_writeopcount > 0, 188 ("creating node not under vn_start_write")); 189 190 MPASS(IFF(type == VLNK, target != NULL)); 191 MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL)); 192 193 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) 194 return (ENOSPC); 195 if (tmpfs_pages_check_avail(tmp, 1) == 0) 196 return (ENOSPC); 197 198 if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) { 199 /* 200 * When a new tmpfs node is created for fully 201 * constructed mount point, there must be a parent 202 * node, which vnode is locked exclusively. As 203 * consequence, if the unmount is executing in 204 * parallel, vflush() cannot reclaim the parent vnode. 205 * Due to this, the check for MNTK_UNMOUNT flag is not 206 * racy: if we did not see MNTK_UNMOUNT flag, then tmp 207 * cannot be destroyed until node construction is 208 * finished and the parent vnode unlocked. 209 * 210 * Tmpfs does not need to instantiate new nodes during 211 * unmount. 212 */ 213 return (EBUSY); 214 } 215 216 nnode = (struct tmpfs_node *)uma_zalloc_arg(tmp->tm_node_pool, tmp, 217 M_WAITOK); 218 219 /* Generic initialization. */ 220 nnode->tn_type = type; 221 vfs_timestamp(&nnode->tn_atime); 222 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = 223 nnode->tn_atime; 224 nnode->tn_uid = uid; 225 nnode->tn_gid = gid; 226 nnode->tn_mode = mode; 227 nnode->tn_id = alloc_unr(tmp->tm_ino_unr); 228 nnode->tn_refcount = 1; 229 230 /* Type-specific initialization. */ 231 switch (nnode->tn_type) { 232 case VBLK: 233 case VCHR: 234 nnode->tn_rdev = rdev; 235 break; 236 237 case VDIR: 238 RB_INIT(&nnode->tn_dir.tn_dirhead); 239 LIST_INIT(&nnode->tn_dir.tn_dupindex); 240 MPASS(parent != nnode); 241 MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL)); 242 nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent; 243 nnode->tn_dir.tn_readdir_lastn = 0; 244 nnode->tn_dir.tn_readdir_lastp = NULL; 245 nnode->tn_links++; 246 TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent); 247 nnode->tn_dir.tn_parent->tn_links++; 248 TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent); 249 break; 250 251 case VFIFO: 252 /* FALLTHROUGH */ 253 case VSOCK: 254 break; 255 256 case VLNK: 257 MPASS(strlen(target) < MAXPATHLEN); 258 nnode->tn_size = strlen(target); 259 nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME, 260 M_WAITOK); 261 memcpy(nnode->tn_link, target, nnode->tn_size); 262 break; 263 264 case VREG: 265 obj = nnode->tn_reg.tn_aobj = 266 vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0, 267 NULL /* XXXKIB - tmpfs needs swap reservation */); 268 VM_OBJECT_WLOCK(obj); 269 /* OBJ_TMPFS is set together with the setting of vp->v_object */ 270 vm_object_set_flag(obj, OBJ_NOSPLIT | OBJ_TMPFS_NODE); 271 vm_object_clear_flag(obj, OBJ_ONEMAPPING); 272 VM_OBJECT_WUNLOCK(obj); 273 break; 274 275 default: 276 panic("tmpfs_alloc_node: type %p %d", nnode, 277 (int)nnode->tn_type); 278 } 279 280 TMPFS_LOCK(tmp); 281 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); 282 nnode->tn_attached = true; 283 tmp->tm_nodes_inuse++; 284 tmp->tm_refcount++; 285 TMPFS_UNLOCK(tmp); 286 287 *node = nnode; 288 return (0); 289} 290 291/* 292 * Destroys the node pointed to by node from the file system 'tmp'. 293 * If the node references a directory, no entries are allowed. 294 */ 295void 296tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) 297{ 298 299 TMPFS_LOCK(tmp); 300 TMPFS_NODE_LOCK(node); 301 if (!tmpfs_free_node_locked(tmp, node, false)) { 302 TMPFS_NODE_UNLOCK(node); 303 TMPFS_UNLOCK(tmp); 304 } 305} 306 307bool 308tmpfs_free_node_locked(struct tmpfs_mount *tmp, struct tmpfs_node *node, 309 bool detach) 310{ 311 vm_object_t uobj; 312 313 TMPFS_MP_ASSERT_LOCKED(tmp); 314 TMPFS_NODE_ASSERT_LOCKED(node); 315 KASSERT(node->tn_refcount > 0, ("node %p refcount zero", node)); 316 317 node->tn_refcount--; 318 if (node->tn_attached && (detach || node->tn_refcount == 0)) { 319 MPASS(tmp->tm_nodes_inuse > 0); 320 tmp->tm_nodes_inuse--; 321 LIST_REMOVE(node, tn_entries); 322 node->tn_attached = false; 323 } 324 if (node->tn_refcount > 0) 325 return (false); 326 327#ifdef INVARIANTS 328 MPASS(node->tn_vnode == NULL); 329 MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0); 330#endif 331 TMPFS_NODE_UNLOCK(node); 332 TMPFS_UNLOCK(tmp); 333 334 switch (node->tn_type) { 335 case VBLK: 336 /* FALLTHROUGH */ 337 case VCHR: 338 /* FALLTHROUGH */ 339 case VDIR: 340 /* FALLTHROUGH */ 341 case VFIFO: 342 /* FALLTHROUGH */ 343 case VSOCK: 344 break; 345 346 case VLNK: 347 free(node->tn_link, M_TMPFSNAME); 348 break; 349 350 case VREG: 351 uobj = node->tn_reg.tn_aobj; 352 if (uobj != NULL) { 353 if (uobj->size != 0) 354 atomic_subtract_long(&tmp->tm_pages_used, uobj->size); 355 KASSERT((uobj->flags & OBJ_TMPFS) == 0, 356 ("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj)); 357 vm_object_deallocate(uobj); 358 } 359 break; 360 361 default: 362 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); 363 } 364 365 free_unr(tmp->tm_ino_unr, node->tn_id); 366 uma_zfree(tmp->tm_node_pool, node); 367 TMPFS_LOCK(tmp); 368 tmpfs_free_tmp(tmp); 369 return (true); 370} 371 372static __inline uint32_t 373tmpfs_dirent_hash(const char *name, u_int len) 374{ 375 uint32_t hash; 376 377 hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK; 378#ifdef TMPFS_DEBUG_DIRCOOKIE_DUP 379 hash &= 0xf; 380#endif 381 if (hash < TMPFS_DIRCOOKIE_MIN) 382 hash += TMPFS_DIRCOOKIE_MIN; 383 384 return (hash); 385} 386 387static __inline off_t 388tmpfs_dirent_cookie(struct tmpfs_dirent *de) 389{ 390 if (de == NULL) 391 return (TMPFS_DIRCOOKIE_EOF); 392 393 MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN); 394 395 return (de->td_cookie); 396} 397 398static __inline boolean_t 399tmpfs_dirent_dup(struct tmpfs_dirent *de) 400{ 401 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0); 402} 403 404static __inline boolean_t 405tmpfs_dirent_duphead(struct tmpfs_dirent *de) 406{ 407 return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0); 408} 409 410void 411tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen) 412{ 413 de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen); 414 memcpy(de->ud.td_name, name, namelen); 415 de->td_namelen = namelen; 416} 417 418/* 419 * Allocates a new directory entry for the node node with a name of name. 420 * The new directory entry is returned in *de. 421 * 422 * The link count of node is increased by one to reflect the new object 423 * referencing it. 424 * 425 * Returns zero on success or an appropriate error code on failure. 426 */ 427int 428tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 429 const char *name, u_int len, struct tmpfs_dirent **de) 430{ 431 struct tmpfs_dirent *nde; 432 433 nde = uma_zalloc(tmp->tm_dirent_pool, M_WAITOK); 434 nde->td_node = node; 435 if (name != NULL) { 436 nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK); 437 tmpfs_dirent_init(nde, name, len); 438 } else 439 nde->td_namelen = 0; 440 if (node != NULL) 441 node->tn_links++; 442 443 *de = nde; 444 445 return 0; 446} 447 448/* 449 * Frees a directory entry. It is the caller's responsibility to destroy 450 * the node referenced by it if needed. 451 * 452 * The link count of node is decreased by one to reflect the removal of an 453 * object that referenced it. This only happens if 'node_exists' is true; 454 * otherwise the function will not access the node referred to by the 455 * directory entry, as it may already have been released from the outside. 456 */ 457void 458tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de) 459{ 460 struct tmpfs_node *node; 461 462 node = de->td_node; 463 if (node != NULL) { 464 MPASS(node->tn_links > 0); 465 node->tn_links--; 466 } 467 if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL) 468 free(de->ud.td_name, M_TMPFSNAME); 469 uma_zfree(tmp->tm_dirent_pool, de); 470} 471 472void 473tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj) 474{ 475 476 ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject"); 477 if (vp->v_type != VREG || obj == NULL) 478 return; 479 480 VM_OBJECT_WLOCK(obj); 481 VI_LOCK(vp); 482 vm_object_clear_flag(obj, OBJ_TMPFS); 483 obj->un_pager.swp.swp_tmpfs = NULL; 484 VI_UNLOCK(vp); 485 VM_OBJECT_WUNLOCK(obj); 486} 487 488/* 489 * Need to clear v_object for insmntque failure. 490 */ 491static void 492tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg) 493{ 494 495 tmpfs_destroy_vobject(vp, vp->v_object); 496 vp->v_object = NULL; 497 vp->v_data = NULL; 498 vp->v_op = &dead_vnodeops; 499 vgone(vp); 500 vput(vp); 501} 502 503/* 504 * Allocates a new vnode for the node node or returns a new reference to 505 * an existing one if the node had already a vnode referencing it. The 506 * resulting locked vnode is returned in *vpp. 507 * 508 * Returns zero on success or an appropriate error code on failure. 509 */ 510int 511tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag, 512 struct vnode **vpp) 513{ 514 struct vnode *vp; 515 struct tmpfs_mount *tm; 516 vm_object_t object; 517 int error; 518 519 error = 0; 520 tm = VFS_TO_TMPFS(mp); 521 TMPFS_NODE_LOCK(node); 522 tmpfs_ref_node_locked(node); 523loop: 524 TMPFS_NODE_ASSERT_LOCKED(node); 525 if ((vp = node->tn_vnode) != NULL) { 526 MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); 527 VI_LOCK(vp); 528 if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) || 529 ((vp->v_iflag & VI_DOOMED) != 0 && 530 (lkflag & LK_NOWAIT) != 0)) { 531 VI_UNLOCK(vp); 532 TMPFS_NODE_UNLOCK(node); 533 error = ENOENT; 534 vp = NULL; 535 goto out; 536 } 537 if ((vp->v_iflag & VI_DOOMED) != 0) { 538 VI_UNLOCK(vp); 539 node->tn_vpstate |= TMPFS_VNODE_WRECLAIM; 540 while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) { 541 msleep(&node->tn_vnode, TMPFS_NODE_MTX(node), 542 0, "tmpfsE", 0); 543 } 544 goto loop; 545 } 546 TMPFS_NODE_UNLOCK(node); 547 error = vget(vp, lkflag | LK_INTERLOCK, curthread); 548 if (error == ENOENT) { 549 TMPFS_NODE_LOCK(node); 550 goto loop; 551 } 552 if (error != 0) { 553 vp = NULL; 554 goto out; 555 } 556 557 /* 558 * Make sure the vnode is still there after 559 * getting the interlock to avoid racing a free. 560 */ 561 if (node->tn_vnode == NULL || node->tn_vnode != vp) { 562 vput(vp); 563 TMPFS_NODE_LOCK(node); 564 goto loop; 565 } 566 567 goto out; 568 } 569 570 if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) || 571 (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) { 572 TMPFS_NODE_UNLOCK(node); 573 error = ENOENT; 574 vp = NULL; 575 goto out; 576 } 577 578 /* 579 * otherwise lock the vp list while we call getnewvnode 580 * since that can block. 581 */ 582 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) { 583 node->tn_vpstate |= TMPFS_VNODE_WANT; 584 error = msleep((caddr_t) &node->tn_vpstate, 585 TMPFS_NODE_MTX(node), 0, "tmpfs_alloc_vp", 0); 586 if (error != 0) 587 goto out; 588 goto loop; 589 } else 590 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING; 591 592 TMPFS_NODE_UNLOCK(node); 593 594 /* Get a new vnode and associate it with our node. */ 595 error = getnewvnode("tmpfs", mp, VFS_TO_TMPFS(mp)->tm_nonc ? 596 &tmpfs_vnodeop_nonc_entries : &tmpfs_vnodeop_entries, &vp); 597 if (error != 0) 598 goto unlock; 599 MPASS(vp != NULL); 600 601 /* lkflag is ignored, the lock is exclusive */ 602 (void) vn_lock(vp, lkflag | LK_RETRY); 603 604 vp->v_data = node; 605 vp->v_type = node->tn_type; 606 607 /* Type-specific initialization. */ 608 switch (node->tn_type) { 609 case VBLK: 610 /* FALLTHROUGH */ 611 case VCHR: 612 /* FALLTHROUGH */ 613 case VLNK: 614 /* FALLTHROUGH */ 615 case VSOCK: 616 break; 617 case VFIFO: 618 vp->v_op = &tmpfs_fifoop_entries; 619 break; 620 case VREG: 621 object = node->tn_reg.tn_aobj; 622 VM_OBJECT_WLOCK(object); 623 VI_LOCK(vp); 624 KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs")); 625 vp->v_object = object; 626 object->un_pager.swp.swp_tmpfs = vp; 627 vm_object_set_flag(object, OBJ_TMPFS); 628 VI_UNLOCK(vp); 629 VM_OBJECT_WUNLOCK(object); 630 break; 631 case VDIR: 632 MPASS(node->tn_dir.tn_parent != NULL); 633 if (node->tn_dir.tn_parent == node) 634 vp->v_vflag |= VV_ROOT; 635 break; 636 637 default: 638 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); 639 } 640 if (vp->v_type != VFIFO) 641 VN_LOCK_ASHARE(vp); 642 643 error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL); 644 if (error != 0) 645 vp = NULL; 646 647unlock: 648 TMPFS_NODE_LOCK(node); 649 650 MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING); 651 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING; 652 node->tn_vnode = vp; 653 654 if (node->tn_vpstate & TMPFS_VNODE_WANT) { 655 node->tn_vpstate &= ~TMPFS_VNODE_WANT; 656 TMPFS_NODE_UNLOCK(node); 657 wakeup((caddr_t) &node->tn_vpstate); 658 } else 659 TMPFS_NODE_UNLOCK(node); 660 661out: 662 if (error == 0) { 663 *vpp = vp; 664 665#ifdef INVARIANTS 666 MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp)); 667 TMPFS_NODE_LOCK(node); 668 MPASS(*vpp == node->tn_vnode); 669 TMPFS_NODE_UNLOCK(node); 670#endif 671 } 672 tmpfs_free_node(tm, node); 673 674 return (error); 675} 676 677/* 678 * Destroys the association between the vnode vp and the node it 679 * references. 680 */ 681void 682tmpfs_free_vp(struct vnode *vp) 683{ 684 struct tmpfs_node *node; 685 686 node = VP_TO_TMPFS_NODE(vp); 687 688 TMPFS_NODE_ASSERT_LOCKED(node); 689 node->tn_vnode = NULL; 690 if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) 691 wakeup(&node->tn_vnode); 692 node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM; 693 vp->v_data = NULL; 694} 695 696/* 697 * Allocates a new file of type 'type' and adds it to the parent directory 698 * 'dvp'; this addition is done using the component name given in 'cnp'. 699 * The ownership of the new file is automatically assigned based on the 700 * credentials of the caller (through 'cnp'), the group is set based on 701 * the parent directory and the mode is determined from the 'vap' argument. 702 * If successful, *vpp holds a vnode to the newly created file and zero 703 * is returned. Otherwise *vpp is NULL and the function returns an 704 * appropriate error code. 705 */ 706int 707tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 708 struct componentname *cnp, char *target) 709{ 710 int error; 711 struct tmpfs_dirent *de; 712 struct tmpfs_mount *tmp; 713 struct tmpfs_node *dnode; 714 struct tmpfs_node *node; 715 struct tmpfs_node *parent; 716 717 ASSERT_VOP_ELOCKED(dvp, "tmpfs_alloc_file"); 718 MPASS(cnp->cn_flags & HASBUF); 719 720 tmp = VFS_TO_TMPFS(dvp->v_mount); 721 dnode = VP_TO_TMPFS_DIR(dvp); 722 *vpp = NULL; 723 724 /* If the entry we are creating is a directory, we cannot overflow 725 * the number of links of its parent, because it will get a new 726 * link. */ 727 if (vap->va_type == VDIR) { 728 /* Ensure that we do not overflow the maximum number of links 729 * imposed by the system. */ 730 MPASS(dnode->tn_links <= LINK_MAX); 731 if (dnode->tn_links == LINK_MAX) { 732 return (EMLINK); 733 } 734 735 parent = dnode; 736 MPASS(parent != NULL); 737 } else 738 parent = NULL; 739 740 /* Allocate a node that represents the new file. */ 741 error = tmpfs_alloc_node(dvp->v_mount, tmp, vap->va_type, 742 cnp->cn_cred->cr_uid, dnode->tn_gid, vap->va_mode, parent, 743 target, vap->va_rdev, &node); 744 if (error != 0) 745 return (error); 746 747 /* Allocate a directory entry that points to the new file. */ 748 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, 749 &de); 750 if (error != 0) { 751 tmpfs_free_node(tmp, node); 752 return (error); 753 } 754 755 /* Allocate a vnode for the new file. */ 756 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp); 757 if (error != 0) { 758 tmpfs_free_dirent(tmp, de); 759 tmpfs_free_node(tmp, node); 760 return (error); 761 } 762 763 /* Now that all required items are allocated, we can proceed to 764 * insert the new node into the directory, an operation that 765 * cannot fail. */ 766 if (cnp->cn_flags & ISWHITEOUT) 767 tmpfs_dir_whiteout_remove(dvp, cnp); 768 tmpfs_dir_attach(dvp, de); 769 return (0); 770} 771 772struct tmpfs_dirent * 773tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) 774{ 775 struct tmpfs_dirent *de; 776 777 de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead); 778 dc->tdc_tree = de; 779 if (de != NULL && tmpfs_dirent_duphead(de)) 780 de = LIST_FIRST(&de->ud.td_duphead); 781 dc->tdc_current = de; 782 783 return (dc->tdc_current); 784} 785 786struct tmpfs_dirent * 787tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) 788{ 789 struct tmpfs_dirent *de; 790 791 MPASS(dc->tdc_tree != NULL); 792 if (tmpfs_dirent_dup(dc->tdc_current)) { 793 dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries); 794 if (dc->tdc_current != NULL) 795 return (dc->tdc_current); 796 } 797 dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir, 798 &dnode->tn_dir.tn_dirhead, dc->tdc_tree); 799 if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) { 800 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); 801 MPASS(dc->tdc_current != NULL); 802 } 803 804 return (dc->tdc_current); 805} 806 807/* Lookup directory entry in RB-Tree. Function may return duphead entry. */ 808static struct tmpfs_dirent * 809tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash) 810{ 811 struct tmpfs_dirent *de, dekey; 812 813 dekey.td_hash = hash; 814 de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey); 815 return (de); 816} 817 818/* Lookup directory entry by cookie, initialize directory cursor accordingly. */ 819static struct tmpfs_dirent * 820tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie, 821 struct tmpfs_dir_cursor *dc) 822{ 823 struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead; 824 struct tmpfs_dirent *de, dekey; 825 826 MPASS(cookie >= TMPFS_DIRCOOKIE_MIN); 827 828 if (cookie == node->tn_dir.tn_readdir_lastn && 829 (de = node->tn_dir.tn_readdir_lastp) != NULL) { 830 /* Protect against possible race, tn_readdir_last[pn] 831 * may be updated with only shared vnode lock held. */ 832 if (cookie == tmpfs_dirent_cookie(de)) 833 goto out; 834 } 835 836 if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) { 837 LIST_FOREACH(de, &node->tn_dir.tn_dupindex, 838 uh.td_dup.index_entries) { 839 MPASS(tmpfs_dirent_dup(de)); 840 if (de->td_cookie == cookie) 841 goto out; 842 /* dupindex list is sorted. */ 843 if (de->td_cookie < cookie) { 844 de = NULL; 845 goto out; 846 } 847 } 848 MPASS(de == NULL); 849 goto out; 850 } 851 852 if ((cookie & TMPFS_DIRCOOKIE_MASK) != cookie) { 853 de = NULL; 854 } else { 855 dekey.td_hash = cookie; 856 /* Recover if direntry for cookie was removed */ 857 de = RB_NFIND(tmpfs_dir, dirhead, &dekey); 858 } 859 dc->tdc_tree = de; 860 dc->tdc_current = de; 861 if (de != NULL && tmpfs_dirent_duphead(de)) { 862 dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); 863 MPASS(dc->tdc_current != NULL); 864 } 865 return (dc->tdc_current); 866 867out: 868 dc->tdc_tree = de; 869 dc->tdc_current = de; 870 if (de != NULL && tmpfs_dirent_dup(de)) 871 dc->tdc_tree = tmpfs_dir_xlookup_hash(node, 872 de->td_hash); 873 return (dc->tdc_current); 874} 875 876/* 877 * Looks for a directory entry in the directory represented by node. 878 * 'cnp' describes the name of the entry to look for. Note that the . 879 * and .. components are not allowed as they do not physically exist 880 * within directories. 881 * 882 * Returns a pointer to the entry when found, otherwise NULL. 883 */ 884struct tmpfs_dirent * 885tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, 886 struct componentname *cnp) 887{ 888 struct tmpfs_dir_duphead *duphead; 889 struct tmpfs_dirent *de; 890 uint32_t hash; 891 892 MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); 893 MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && 894 cnp->cn_nameptr[1] == '.'))); 895 TMPFS_VALIDATE_DIR(node); 896 897 hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen); 898 de = tmpfs_dir_xlookup_hash(node, hash); 899 if (de != NULL && tmpfs_dirent_duphead(de)) { 900 duphead = &de->ud.td_duphead; 901 LIST_FOREACH(de, duphead, uh.td_dup.entries) { 902 if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, 903 cnp->cn_namelen)) 904 break; 905 } 906 } else if (de != NULL) { 907 if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, 908 cnp->cn_namelen)) 909 de = NULL; 910 } 911 if (de != NULL && f != NULL && de->td_node != f) 912 de = NULL; 913 914 return (de); 915} 916 917/* 918 * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex 919 * list, allocate new cookie value. 920 */ 921static void 922tmpfs_dir_attach_dup(struct tmpfs_node *dnode, 923 struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde) 924{ 925 struct tmpfs_dir_duphead *dupindex; 926 struct tmpfs_dirent *de, *pde; 927 928 dupindex = &dnode->tn_dir.tn_dupindex; 929 de = LIST_FIRST(dupindex); 930 if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) { 931 if (de == NULL) 932 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; 933 else 934 nde->td_cookie = de->td_cookie + 1; 935 MPASS(tmpfs_dirent_dup(nde)); 936 LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries); 937 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 938 return; 939 } 940 941 /* 942 * Cookie numbers are near exhaustion. Scan dupindex list for unused 943 * numbers. dupindex list is sorted in descending order. Keep it so 944 * after inserting nde. 945 */ 946 while (1) { 947 pde = de; 948 de = LIST_NEXT(de, uh.td_dup.index_entries); 949 if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) { 950 /* 951 * Last element of the index doesn't have minimal cookie 952 * value, use it. 953 */ 954 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; 955 LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries); 956 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 957 return; 958 } else if (de == NULL) { 959 /* 960 * We are so lucky have 2^30 hash duplicates in single 961 * directory :) Return largest possible cookie value. 962 * It should be fine except possible issues with 963 * VOP_READDIR restart. 964 */ 965 nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX; 966 LIST_INSERT_HEAD(dupindex, nde, 967 uh.td_dup.index_entries); 968 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 969 return; 970 } 971 if (de->td_cookie + 1 == pde->td_cookie || 972 de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX) 973 continue; /* No hole or invalid cookie. */ 974 nde->td_cookie = de->td_cookie + 1; 975 MPASS(tmpfs_dirent_dup(nde)); 976 MPASS(pde->td_cookie > nde->td_cookie); 977 MPASS(nde->td_cookie > de->td_cookie); 978 LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries); 979 LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); 980 return; 981 } 982} 983 984/* 985 * Attaches the directory entry de to the directory represented by vp. 986 * Note that this does not change the link count of the node pointed by 987 * the directory entry, as this is done by tmpfs_alloc_dirent. 988 */ 989void 990tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) 991{ 992 struct tmpfs_node *dnode; 993 struct tmpfs_dirent *xde, *nde; 994 995 ASSERT_VOP_ELOCKED(vp, __func__); 996 MPASS(de->td_namelen > 0); 997 MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN); 998 MPASS(de->td_cookie == de->td_hash); 999 1000 dnode = VP_TO_TMPFS_DIR(vp); 1001 dnode->tn_dir.tn_readdir_lastn = 0; 1002 dnode->tn_dir.tn_readdir_lastp = NULL; 1003 1004 MPASS(!tmpfs_dirent_dup(de)); 1005 xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); 1006 if (xde != NULL && tmpfs_dirent_duphead(xde)) 1007 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); 1008 else if (xde != NULL) { 1009 /* 1010 * Allocate new duphead. Swap xde with duphead to avoid 1011 * adding/removing elements with the same hash. 1012 */ 1013 MPASS(!tmpfs_dirent_dup(xde)); 1014 tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0, 1015 &nde); 1016 /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */ 1017 memcpy(nde, xde, sizeof(*xde)); 1018 xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD; 1019 LIST_INIT(&xde->ud.td_duphead); 1020 xde->td_namelen = 0; 1021 xde->td_node = NULL; 1022 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde); 1023 tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); 1024 } 1025 dnode->tn_size += sizeof(struct tmpfs_dirent); 1026 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 1027 TMPFS_NODE_MODIFIED; 1028 tmpfs_update(vp); 1029} 1030 1031/* 1032 * Detaches the directory entry de from the directory represented by vp. 1033 * Note that this does not change the link count of the node pointed by 1034 * the directory entry, as this is done by tmpfs_free_dirent. 1035 */ 1036void 1037tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) 1038{ 1039 struct tmpfs_mount *tmp; 1040 struct tmpfs_dir *head; 1041 struct tmpfs_node *dnode; 1042 struct tmpfs_dirent *xde; 1043 1044 ASSERT_VOP_ELOCKED(vp, __func__); 1045 1046 dnode = VP_TO_TMPFS_DIR(vp); 1047 head = &dnode->tn_dir.tn_dirhead; 1048 dnode->tn_dir.tn_readdir_lastn = 0; 1049 dnode->tn_dir.tn_readdir_lastp = NULL; 1050 1051 if (tmpfs_dirent_dup(de)) { 1052 /* Remove duphead if de was last entry. */ 1053 if (LIST_NEXT(de, uh.td_dup.entries) == NULL) { 1054 xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash); 1055 MPASS(tmpfs_dirent_duphead(xde)); 1056 } else 1057 xde = NULL; 1058 LIST_REMOVE(de, uh.td_dup.entries); 1059 LIST_REMOVE(de, uh.td_dup.index_entries); 1060 if (xde != NULL) { 1061 if (LIST_EMPTY(&xde->ud.td_duphead)) { 1062 RB_REMOVE(tmpfs_dir, head, xde); 1063 tmp = VFS_TO_TMPFS(vp->v_mount); 1064 MPASS(xde->td_node == NULL); 1065 tmpfs_free_dirent(tmp, xde); 1066 } 1067 } 1068 de->td_cookie = de->td_hash; 1069 } else 1070 RB_REMOVE(tmpfs_dir, head, de); 1071 1072 dnode->tn_size -= sizeof(struct tmpfs_dirent); 1073 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 1074 TMPFS_NODE_MODIFIED; 1075 tmpfs_update(vp); 1076} 1077 1078void 1079tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode) 1080{ 1081 struct tmpfs_dirent *de, *dde, *nde; 1082 1083 RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) { 1084 RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); 1085 /* Node may already be destroyed. */ 1086 de->td_node = NULL; 1087 if (tmpfs_dirent_duphead(de)) { 1088 while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) { 1089 LIST_REMOVE(dde, uh.td_dup.entries); 1090 dde->td_node = NULL; 1091 tmpfs_free_dirent(tmp, dde); 1092 } 1093 } 1094 tmpfs_free_dirent(tmp, de); 1095 } 1096} 1097 1098/* 1099 * Helper function for tmpfs_readdir. Creates a '.' entry for the given 1100 * directory and returns it in the uio space. The function returns 0 1101 * on success, -1 if there was not enough space in the uio structure to 1102 * hold the directory entry or an appropriate error code if another 1103 * error happens. 1104 */ 1105static int 1106tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) 1107{ 1108 int error; 1109 struct dirent dent; 1110 1111 TMPFS_VALIDATE_DIR(node); 1112 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); 1113 1114 dent.d_fileno = node->tn_id; 1115 dent.d_type = DT_DIR; 1116 dent.d_namlen = 1; 1117 dent.d_name[0] = '.'; 1118 dent.d_name[1] = '\0'; 1119 dent.d_reclen = GENERIC_DIRSIZ(&dent); 1120 1121 if (dent.d_reclen > uio->uio_resid) 1122 error = EJUSTRETURN; 1123 else 1124 error = uiomove(&dent, dent.d_reclen, uio); 1125 1126 tmpfs_set_status(node, TMPFS_NODE_ACCESSED); 1127 1128 return (error); 1129} 1130 1131/* 1132 * Helper function for tmpfs_readdir. Creates a '..' entry for the given 1133 * directory and returns it in the uio space. The function returns 0 1134 * on success, -1 if there was not enough space in the uio structure to 1135 * hold the directory entry or an appropriate error code if another 1136 * error happens. 1137 */ 1138static int 1139tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio) 1140{ 1141 int error; 1142 struct dirent dent; 1143 1144 TMPFS_VALIDATE_DIR(node); 1145 MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); 1146 1147 /* 1148 * Return ENOENT if the current node is already removed. 1149 */ 1150 TMPFS_ASSERT_LOCKED(node); 1151 if (node->tn_dir.tn_parent == NULL) 1152 return (ENOENT); 1153 1154 TMPFS_NODE_LOCK(node->tn_dir.tn_parent); 1155 dent.d_fileno = node->tn_dir.tn_parent->tn_id; 1156 TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent); 1157 1158 dent.d_type = DT_DIR; 1159 dent.d_namlen = 2; 1160 dent.d_name[0] = '.'; 1161 dent.d_name[1] = '.'; 1162 dent.d_name[2] = '\0'; 1163 dent.d_reclen = GENERIC_DIRSIZ(&dent); 1164 1165 if (dent.d_reclen > uio->uio_resid) 1166 error = EJUSTRETURN; 1167 else 1168 error = uiomove(&dent, dent.d_reclen, uio); 1169 1170 tmpfs_set_status(node, TMPFS_NODE_ACCESSED); 1171 1172 return (error); 1173} 1174 1175/* 1176 * Helper function for tmpfs_readdir. Returns as much directory entries 1177 * as can fit in the uio space. The read starts at uio->uio_offset. 1178 * The function returns 0 on success, -1 if there was not enough space 1179 * in the uio structure to hold the directory entry or an appropriate 1180 * error code if another error happens. 1181 */ 1182int 1183tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, int maxcookies, 1184 u_long *cookies, int *ncookies) 1185{ 1186 struct tmpfs_dir_cursor dc; 1187 struct tmpfs_dirent *de; 1188 off_t off; 1189 int error; 1190 1191 TMPFS_VALIDATE_DIR(node); 1192 1193 off = 0; 1194 1195 /* 1196 * Lookup the node from the current offset. The starting offset of 1197 * 0 will lookup both '.' and '..', and then the first real entry, 1198 * or EOF if there are none. Then find all entries for the dir that 1199 * fit into the buffer. Once no more entries are found (de == NULL), 1200 * the offset is set to TMPFS_DIRCOOKIE_EOF, which will cause the next 1201 * call to return 0. 1202 */ 1203 switch (uio->uio_offset) { 1204 case TMPFS_DIRCOOKIE_DOT: 1205 error = tmpfs_dir_getdotdent(node, uio); 1206 if (error != 0) 1207 return (error); 1208 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 1209 if (cookies != NULL) 1210 cookies[(*ncookies)++] = off = uio->uio_offset; 1211 /* FALLTHROUGH */ 1212 case TMPFS_DIRCOOKIE_DOTDOT: 1213 error = tmpfs_dir_getdotdotdent(node, uio); 1214 if (error != 0) 1215 return (error); 1216 de = tmpfs_dir_first(node, &dc); 1217 uio->uio_offset = tmpfs_dirent_cookie(de); 1218 if (cookies != NULL) 1219 cookies[(*ncookies)++] = off = uio->uio_offset; 1220 /* EOF. */ 1221 if (de == NULL) 1222 return (0); 1223 break; 1224 case TMPFS_DIRCOOKIE_EOF: 1225 return (0); 1226 default: 1227 de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc); 1228 if (de == NULL) 1229 return (EINVAL); 1230 if (cookies != NULL) 1231 off = tmpfs_dirent_cookie(de); 1232 } 1233 1234 /* Read as much entries as possible; i.e., until we reach the end of 1235 * the directory or we exhaust uio space. */ 1236 do { 1237 struct dirent d; 1238 1239 /* Create a dirent structure representing the current 1240 * tmpfs_node and fill it. */ 1241 if (de->td_node == NULL) { 1242 d.d_fileno = 1; 1243 d.d_type = DT_WHT; 1244 } else { 1245 d.d_fileno = de->td_node->tn_id; 1246 switch (de->td_node->tn_type) { 1247 case VBLK: 1248 d.d_type = DT_BLK; 1249 break; 1250 1251 case VCHR: 1252 d.d_type = DT_CHR; 1253 break; 1254 1255 case VDIR: 1256 d.d_type = DT_DIR; 1257 break; 1258 1259 case VFIFO: 1260 d.d_type = DT_FIFO; 1261 break; 1262 1263 case VLNK: 1264 d.d_type = DT_LNK; 1265 break; 1266 1267 case VREG: 1268 d.d_type = DT_REG; 1269 break; 1270 1271 case VSOCK: 1272 d.d_type = DT_SOCK; 1273 break; 1274 1275 default: 1276 panic("tmpfs_dir_getdents: type %p %d", 1277 de->td_node, (int)de->td_node->tn_type); 1278 } 1279 } 1280 d.d_namlen = de->td_namelen; 1281 MPASS(de->td_namelen < sizeof(d.d_name)); 1282 (void)memcpy(d.d_name, de->ud.td_name, de->td_namelen); 1283 d.d_name[de->td_namelen] = '\0'; 1284 d.d_reclen = GENERIC_DIRSIZ(&d); 1285 1286 /* Stop reading if the directory entry we are treating is 1287 * bigger than the amount of data that can be returned. */ 1288 if (d.d_reclen > uio->uio_resid) { 1289 error = EJUSTRETURN; 1290 break; 1291 } 1292 1293 /* Copy the new dirent structure into the output buffer and 1294 * advance pointers. */ 1295 error = uiomove(&d, d.d_reclen, uio); 1296 if (error == 0) { 1297 de = tmpfs_dir_next(node, &dc); 1298 if (cookies != NULL) { 1299 off = tmpfs_dirent_cookie(de); 1300 MPASS(*ncookies < maxcookies); 1301 cookies[(*ncookies)++] = off; 1302 } 1303 } 1304 } while (error == 0 && uio->uio_resid > 0 && de != NULL); 1305 1306 /* Skip setting off when using cookies as it is already done above. */ 1307 if (cookies == NULL) 1308 off = tmpfs_dirent_cookie(de); 1309 1310 /* Update the offset and cache. */ 1311 uio->uio_offset = off; 1312 node->tn_dir.tn_readdir_lastn = off; 1313 node->tn_dir.tn_readdir_lastp = de; 1314 1315 tmpfs_set_status(node, TMPFS_NODE_ACCESSED); 1316 return error; 1317} 1318 1319int 1320tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp) 1321{ 1322 struct tmpfs_dirent *de; 1323 int error; 1324 1325 error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL, 1326 cnp->cn_nameptr, cnp->cn_namelen, &de); 1327 if (error != 0) 1328 return (error); 1329 tmpfs_dir_attach(dvp, de); 1330 return (0); 1331} 1332 1333void 1334tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) 1335{ 1336 struct tmpfs_dirent *de; 1337 1338 de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp); 1339 MPASS(de != NULL && de->td_node == NULL); 1340 tmpfs_dir_detach(dvp, de); 1341 tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de); 1342} 1343 1344/* 1345 * Resizes the aobj associated with the regular file pointed to by 'vp' to the 1346 * size 'newsize'. 'vp' must point to a vnode that represents a regular file. 1347 * 'newsize' must be positive. 1348 * 1349 * Returns zero on success or an appropriate error code on failure. 1350 */ 1351int 1352tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) 1353{ 1354 struct tmpfs_mount *tmp; 1355 struct tmpfs_node *node; 1356 vm_object_t uobj; 1357 vm_page_t m; 1358 vm_pindex_t idx, newpages, oldpages; 1359 off_t oldsize; 1360 int base, rv; 1361 1362 MPASS(vp->v_type == VREG); 1363 MPASS(newsize >= 0); 1364 1365 node = VP_TO_TMPFS_NODE(vp); 1366 uobj = node->tn_reg.tn_aobj; 1367 tmp = VFS_TO_TMPFS(vp->v_mount); 1368 1369 /* 1370 * Convert the old and new sizes to the number of pages needed to 1371 * store them. It may happen that we do not need to do anything 1372 * because the last allocated page can accommodate the change on 1373 * its own. 1374 */ 1375 oldsize = node->tn_size; 1376 oldpages = OFF_TO_IDX(oldsize + PAGE_MASK); 1377 MPASS(oldpages == uobj->size); 1378 newpages = OFF_TO_IDX(newsize + PAGE_MASK); 1379 1380 if (__predict_true(newpages == oldpages && newsize >= oldsize)) { 1381 node->tn_size = newsize; 1382 return (0); 1383 } 1384 1385 if (newpages > oldpages && 1386 tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0) 1387 return (ENOSPC); 1388 1389 VM_OBJECT_WLOCK(uobj); 1390 if (newsize < oldsize) { 1391 /* 1392 * Zero the truncated part of the last page. 1393 */ 1394 base = newsize & PAGE_MASK; 1395 if (base != 0) { 1396 idx = OFF_TO_IDX(newsize); 1397retry: 1398 m = vm_page_lookup(uobj, idx); 1399 if (m != NULL) { 1400 if (vm_page_sleep_if_busy(m, "tmfssz")) 1401 goto retry; 1402 MPASS(m->valid == VM_PAGE_BITS_ALL); 1403 } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { 1404 m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL | 1405 VM_ALLOC_WAITFAIL); 1406 if (m == NULL) 1407 goto retry; 1408 rv = vm_pager_get_pages(uobj, &m, 1, NULL, 1409 NULL); 1410 vm_page_lock(m); 1411 if (rv == VM_PAGER_OK) { 1412 vm_page_deactivate(m); 1413 vm_page_unlock(m); 1414 vm_page_xunbusy(m); 1415 } else { 1416 vm_page_free(m); 1417 vm_page_unlock(m); 1418 if (ignerr) 1419 m = NULL; 1420 else { 1421 VM_OBJECT_WUNLOCK(uobj); 1422 return (EIO); 1423 } 1424 } 1425 } 1426 if (m != NULL) { 1427 pmap_zero_page_area(m, base, PAGE_SIZE - base); 1428 vm_page_dirty(m); 1429 vm_pager_page_unswapped(m); 1430 } 1431 } 1432 1433 /* 1434 * Release any swap space and free any whole pages. 1435 */ 1436 if (newpages < oldpages) { 1437 swap_pager_freespace(uobj, newpages, oldpages - 1438 newpages); 1439 vm_object_page_remove(uobj, newpages, 0, 0); 1440 } 1441 } 1442 uobj->size = newpages; 1443 VM_OBJECT_WUNLOCK(uobj); 1444 1445 atomic_add_long(&tmp->tm_pages_used, newpages - oldpages); 1446 1447 node->tn_size = newsize; 1448 return (0); 1449} 1450 1451void 1452tmpfs_check_mtime(struct vnode *vp) 1453{ 1454 struct tmpfs_node *node; 1455 struct vm_object *obj; 1456 1457 ASSERT_VOP_ELOCKED(vp, "check_mtime"); 1458 if (vp->v_type != VREG) 1459 return; 1460 obj = vp->v_object; 1461 KASSERT((obj->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) == 1462 (OBJ_TMPFS_NODE | OBJ_TMPFS), ("non-tmpfs obj")); 1463 /* unlocked read */ 1464 if ((obj->flags & OBJ_TMPFS_DIRTY) != 0) { 1465 VM_OBJECT_WLOCK(obj); 1466 if ((obj->flags & OBJ_TMPFS_DIRTY) != 0) { 1467 obj->flags &= ~OBJ_TMPFS_DIRTY; 1468 node = VP_TO_TMPFS_NODE(vp); 1469 node->tn_status |= TMPFS_NODE_MODIFIED | 1470 TMPFS_NODE_CHANGED; 1471 } 1472 VM_OBJECT_WUNLOCK(obj); 1473 } 1474} 1475 1476/* 1477 * Change flags of the given vnode. 1478 * Caller should execute tmpfs_update on vp after a successful execution. 1479 * The vnode must be locked on entry and remain locked on exit. 1480 */ 1481int 1482tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred, 1483 struct thread *p) 1484{ 1485 int error; 1486 struct tmpfs_node *node; 1487 1488 ASSERT_VOP_ELOCKED(vp, "chflags"); 1489 1490 node = VP_TO_TMPFS_NODE(vp); 1491 1492 if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK | 1493 UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP | 1494 UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE | 1495 UF_SPARSE | UF_SYSTEM)) != 0) 1496 return (EOPNOTSUPP); 1497 1498 /* Disallow this operation if the file system is mounted read-only. */ 1499 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1500 return EROFS; 1501 1502 /* 1503 * Callers may only modify the file flags on objects they 1504 * have VADMIN rights for. 1505 */ 1506 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1507 return (error); 1508 /* 1509 * Unprivileged processes are not permitted to unset system 1510 * flags, or modify flags if any system flags are set. 1511 */ 1512 if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) { 1513 if (node->tn_flags & 1514 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) { 1515 error = securelevel_gt(cred, 0); 1516 if (error) 1517 return (error); 1518 } 1519 } else { 1520 if (node->tn_flags & 1521 (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || 1522 ((flags ^ node->tn_flags) & SF_SETTABLE)) 1523 return (EPERM); 1524 } 1525 node->tn_flags = flags; 1526 node->tn_status |= TMPFS_NODE_CHANGED; 1527 1528 ASSERT_VOP_ELOCKED(vp, "chflags2"); 1529 1530 return (0); 1531} 1532 1533/* 1534 * Change access mode on the given vnode. 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 */ 1538int 1539tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p) 1540{ 1541 int error; 1542 struct tmpfs_node *node; 1543 1544 ASSERT_VOP_ELOCKED(vp, "chmod"); 1545 1546 node = VP_TO_TMPFS_NODE(vp); 1547 1548 /* Disallow this operation if the file system is mounted read-only. */ 1549 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1550 return EROFS; 1551 1552 /* Immutable or append-only files cannot be modified, either. */ 1553 if (node->tn_flags & (IMMUTABLE | APPEND)) 1554 return EPERM; 1555 1556 /* 1557 * To modify the permissions on a file, must possess VADMIN 1558 * for that file. 1559 */ 1560 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1561 return (error); 1562 1563 /* 1564 * Privileged processes may set the sticky bit on non-directories, 1565 * as well as set the setgid bit on a file with a group that the 1566 * process is not a member of. 1567 */ 1568 if (vp->v_type != VDIR && (mode & S_ISTXT)) { 1569 if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0)) 1570 return (EFTYPE); 1571 } 1572 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) { 1573 error = priv_check_cred(cred, PRIV_VFS_SETGID, 0); 1574 if (error) 1575 return (error); 1576 } 1577 1578 1579 node->tn_mode &= ~ALLPERMS; 1580 node->tn_mode |= mode & ALLPERMS; 1581 1582 node->tn_status |= TMPFS_NODE_CHANGED; 1583 1584 ASSERT_VOP_ELOCKED(vp, "chmod2"); 1585 1586 return (0); 1587} 1588 1589/* 1590 * Change ownership of the given vnode. At least one of uid or gid must 1591 * be different than VNOVAL. If one is set to that value, the attribute 1592 * is unchanged. 1593 * Caller should execute tmpfs_update on vp after a successful execution. 1594 * The vnode must be locked on entry and remain locked on exit. 1595 */ 1596int 1597tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, 1598 struct thread *p) 1599{ 1600 int error; 1601 struct tmpfs_node *node; 1602 uid_t ouid; 1603 gid_t ogid; 1604 1605 ASSERT_VOP_ELOCKED(vp, "chown"); 1606 1607 node = VP_TO_TMPFS_NODE(vp); 1608 1609 /* Assign default values if they are unknown. */ 1610 MPASS(uid != VNOVAL || gid != VNOVAL); 1611 if (uid == VNOVAL) 1612 uid = node->tn_uid; 1613 if (gid == VNOVAL) 1614 gid = node->tn_gid; 1615 MPASS(uid != VNOVAL && gid != VNOVAL); 1616 1617 /* Disallow this operation if the file system is mounted read-only. */ 1618 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1619 return EROFS; 1620 1621 /* Immutable or append-only files cannot be modified, either. */ 1622 if (node->tn_flags & (IMMUTABLE | APPEND)) 1623 return EPERM; 1624 1625 /* 1626 * To modify the ownership of a file, must possess VADMIN for that 1627 * file. 1628 */ 1629 if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) 1630 return (error); 1631 1632 /* 1633 * To change the owner of a file, or change the group of a file to a 1634 * group of which we are not a member, the caller must have 1635 * privilege. 1636 */ 1637 if ((uid != node->tn_uid || 1638 (gid != node->tn_gid && !groupmember(gid, cred))) && 1639 (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0))) 1640 return (error); 1641 1642 ogid = node->tn_gid; 1643 ouid = node->tn_uid; 1644 1645 node->tn_uid = uid; 1646 node->tn_gid = gid; 1647 1648 node->tn_status |= TMPFS_NODE_CHANGED; 1649 1650 if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) { 1651 if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0)) 1652 node->tn_mode &= ~(S_ISUID | S_ISGID); 1653 } 1654 1655 ASSERT_VOP_ELOCKED(vp, "chown2"); 1656 1657 return (0); 1658} 1659 1660/* 1661 * Change size of the given vnode. 1662 * Caller should execute tmpfs_update on vp after a successful execution. 1663 * The vnode must be locked on entry and remain locked on exit. 1664 */ 1665int 1666tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, 1667 struct thread *p) 1668{ 1669 int error; 1670 struct tmpfs_node *node; 1671 1672 ASSERT_VOP_ELOCKED(vp, "chsize"); 1673 1674 node = VP_TO_TMPFS_NODE(vp); 1675 1676 /* Decide whether this is a valid operation based on the file type. */ 1677 error = 0; 1678 switch (vp->v_type) { 1679 case VDIR: 1680 return EISDIR; 1681 1682 case VREG: 1683 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1684 return EROFS; 1685 break; 1686 1687 case VBLK: 1688 /* FALLTHROUGH */ 1689 case VCHR: 1690 /* FALLTHROUGH */ 1691 case VFIFO: 1692 /* Allow modifications of special files even if in the file 1693 * system is mounted read-only (we are not modifying the 1694 * files themselves, but the objects they represent). */ 1695 return 0; 1696 1697 default: 1698 /* Anything else is unsupported. */ 1699 return EOPNOTSUPP; 1700 } 1701 1702 /* Immutable or append-only files cannot be modified, either. */ 1703 if (node->tn_flags & (IMMUTABLE | APPEND)) 1704 return EPERM; 1705 1706 error = tmpfs_truncate(vp, size); 1707 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents 1708 * for us, as will update tn_status; no need to do that here. */ 1709 1710 ASSERT_VOP_ELOCKED(vp, "chsize2"); 1711 1712 return (error); 1713} 1714 1715/* 1716 * Change access and modification times of the given vnode. 1717 * Caller should execute tmpfs_update on vp after a successful execution. 1718 * The vnode must be locked on entry and remain locked on exit. 1719 */ 1720int 1721tmpfs_chtimes(struct vnode *vp, struct vattr *vap, 1722 struct ucred *cred, struct thread *l) 1723{ 1724 int error; 1725 struct tmpfs_node *node; 1726 1727 ASSERT_VOP_ELOCKED(vp, "chtimes"); 1728 1729 node = VP_TO_TMPFS_NODE(vp); 1730 1731 /* Disallow this operation if the file system is mounted read-only. */ 1732 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1733 return EROFS; 1734 1735 /* Immutable or append-only files cannot be modified, either. */ 1736 if (node->tn_flags & (IMMUTABLE | APPEND)) 1737 return EPERM; 1738 1739 error = vn_utimes_perm(vp, vap, cred, l); 1740 if (error != 0) 1741 return (error); 1742 1743 if (vap->va_atime.tv_sec != VNOVAL) 1744 node->tn_status |= TMPFS_NODE_ACCESSED; 1745 1746 if (vap->va_mtime.tv_sec != VNOVAL) 1747 node->tn_status |= TMPFS_NODE_MODIFIED; 1748 1749 if (vap->va_birthtime.tv_sec != VNOVAL) 1750 node->tn_status |= TMPFS_NODE_MODIFIED; 1751 1752 tmpfs_itimes(vp, &vap->va_atime, &vap->va_mtime); 1753 1754 if (vap->va_birthtime.tv_sec != VNOVAL) 1755 node->tn_birthtime = vap->va_birthtime; 1756 ASSERT_VOP_ELOCKED(vp, "chtimes2"); 1757 1758 return (0); 1759} 1760 1761void 1762tmpfs_set_status(struct tmpfs_node *node, int status) 1763{ 1764 1765 if ((node->tn_status & status) == status) 1766 return; 1767 TMPFS_NODE_LOCK(node); 1768 node->tn_status |= status; 1769 TMPFS_NODE_UNLOCK(node); 1770} 1771 1772/* Sync timestamps */ 1773void 1774tmpfs_itimes(struct vnode *vp, const struct timespec *acc, 1775 const struct timespec *mod) 1776{ 1777 struct tmpfs_node *node; 1778 struct timespec now; 1779 1780 ASSERT_VOP_LOCKED(vp, "tmpfs_itimes"); 1781 node = VP_TO_TMPFS_NODE(vp); 1782 1783 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1784 TMPFS_NODE_CHANGED)) == 0) 1785 return; 1786 1787 vfs_timestamp(&now); 1788 TMPFS_NODE_LOCK(node); 1789 if (node->tn_status & TMPFS_NODE_ACCESSED) { 1790 if (acc == NULL) 1791 acc = &now; 1792 node->tn_atime = *acc; 1793 } 1794 if (node->tn_status & TMPFS_NODE_MODIFIED) { 1795 if (mod == NULL) 1796 mod = &now; 1797 node->tn_mtime = *mod; 1798 } 1799 if (node->tn_status & TMPFS_NODE_CHANGED) 1800 node->tn_ctime = now; 1801 node->tn_status &= ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1802 TMPFS_NODE_CHANGED); 1803 TMPFS_NODE_UNLOCK(node); 1804 1805 /* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */ 1806 random_harvest_queue(node, sizeof(*node), 1, RANDOM_FS_ATIME); 1807} 1808 1809void 1810tmpfs_update(struct vnode *vp) 1811{ 1812 1813 tmpfs_itimes(vp, NULL, NULL); 1814} 1815 1816int 1817tmpfs_truncate(struct vnode *vp, off_t length) 1818{ 1819 int error; 1820 struct tmpfs_node *node; 1821 1822 node = VP_TO_TMPFS_NODE(vp); 1823 1824 if (length < 0) { 1825 error = EINVAL; 1826 goto out; 1827 } 1828 1829 if (node->tn_size == length) { 1830 error = 0; 1831 goto out; 1832 } 1833 1834 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) 1835 return (EFBIG); 1836 1837 error = tmpfs_reg_resize(vp, length, FALSE); 1838 if (error == 0) 1839 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; 1840 1841out: 1842 tmpfs_update(vp); 1843 1844 return (error); 1845} 1846 1847static __inline int 1848tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b) 1849{ 1850 if (a->td_hash > b->td_hash) 1851 return (1); 1852 else if (a->td_hash < b->td_hash) 1853 return (-1); 1854 return (0); 1855} 1856 1857RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); 1858