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 37 #include <sys/kernel.h> 38 #include <sys/param.h> 39 #include <sys/priv.h> 40 #include <sys/proc.h> 41 #include <sys/stat.h> 42 #include <sys/systm.h> 43 #include <sys/vnode.h> 44 #include <sys/vmmeter.h> 45 #include <sys/malloc.h> 46 47 #include <vm/vm.h> 48 #include <vm/vm_object.h> 49 #include <vm/vm_page.h> 50 #include <vm/vm_pager.h> 51 #include <vm/vm_extern.h> 52 #include <vm/vm_pageout.h> 53 #include <vm/vm_page2.h> 54 55 #include <vfs/tmpfs/tmpfs.h> 56 #include <vfs/tmpfs/tmpfs_vnops.h> 57 58 static ino_t tmpfs_fetch_ino(struct tmpfs_mount *); 59 60 static int tmpfs_dirtree_compare(struct tmpfs_dirent *a, 61 struct tmpfs_dirent *b); 62 RB_GENERATE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare); 63 64 static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, 65 struct tmpfs_dirent *b); 66 RB_GENERATE(tmpfs_dirtree_cookie, tmpfs_dirent, 67 rb_cookienode, tmpfs_dirtree_compare_cookie); 68 69 70 /* --------------------------------------------------------------------- */ 71 72 /* 73 * Allocates a new node of type 'type' inside the 'tmp' mount point, with 74 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', 75 * using the credentials of the process 'p'. 76 * 77 * If the node type is set to 'VDIR', then the parent parameter must point 78 * to the parent directory of the node being created. It may only be NULL 79 * while allocating the root node. 80 * 81 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter 82 * specifies the device the node represents. 83 * 84 * If the node type is set to 'VLNK', then the parameter target specifies 85 * the file name of the target file for the symbolic link that is being 86 * created. 87 * 88 * Note that new nodes are retrieved from the available list if it has 89 * items or, if it is empty, from the node pool as long as there is enough 90 * space to create them. 91 * 92 * Returns zero on success or an appropriate error code on failure. 93 */ 94 int 95 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type, 96 uid_t uid, gid_t gid, mode_t mode, 97 char *target, int rmajor, int rminor, 98 struct tmpfs_node **node) 99 { 100 struct tmpfs_node *nnode; 101 struct timespec ts; 102 dev_t rdev; 103 104 KKASSERT(IFF(type == VLNK, target != NULL)); 105 KKASSERT(IFF(type == VBLK || type == VCHR, rmajor != VNOVAL)); 106 107 if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) 108 return (ENOSPC); 109 110 nnode = kmalloc_obj(sizeof(struct tmpfs_node), tmp->tm_node_zone, 111 M_WAITOK | M_ZERO | M_NULLOK); 112 if (nnode == NULL) 113 return (ENOSPC); 114 tmpfs_node_init(nnode); 115 116 /* Generic initialization. */ 117 nnode->tn_type = type; 118 vfs_timestamp(&ts); 119 nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime 120 = ts.tv_sec; 121 nnode->tn_ctimensec = nnode->tn_mtimensec = nnode->tn_atimensec 122 = ts.tv_nsec; 123 nnode->tn_uid = uid; 124 nnode->tn_gid = gid; 125 nnode->tn_mode = mode; 126 nnode->tn_id = tmpfs_fetch_ino(tmp); 127 nnode->tn_advlock.init_done = 0; 128 KKASSERT(nnode->tn_links == 0); 129 130 /* Type-specific initialization. */ 131 switch (nnode->tn_type) { 132 case VBLK: 133 case VCHR: 134 rdev = makeudev(rmajor, rminor); 135 if (rdev == NOUDEV) { 136 tmpfs_node_uninit(nnode); 137 kfree_obj(nnode, tmp->tm_node_zone); 138 return(EINVAL); 139 } 140 nnode->tn_rdev = rdev; 141 break; 142 143 case VDIR: 144 RB_INIT(&nnode->tn_dir.tn_dirtree); 145 RB_INIT(&nnode->tn_dir.tn_cookietree); 146 nnode->tn_dir.tn_parent = NULL; 147 nnode->tn_size = 0; 148 break; 149 150 case VFIFO: 151 /* FALLTHROUGH */ 152 case VSOCK: 153 break; 154 155 case VLNK: 156 nnode->tn_size = strlen(target); 157 nnode->tn_link = kmalloc(nnode->tn_size + 1, tmp->tm_name_zone, 158 M_WAITOK | M_NULLOK); 159 if (nnode->tn_link == NULL) { 160 tmpfs_node_uninit(nnode); 161 kfree_obj(nnode, tmp->tm_node_zone); 162 return (ENOSPC); 163 } 164 bcopy(target, nnode->tn_link, nnode->tn_size); 165 nnode->tn_link[nnode->tn_size] = '\0'; 166 break; 167 168 case VREG: 169 nnode->tn_reg.tn_aobj = swap_pager_alloc(NULL, 0, 170 VM_PROT_DEFAULT, 0); 171 nnode->tn_reg.tn_aobj_pages = 0; 172 nnode->tn_size = 0; 173 vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_NOPAGEIN); 174 break; 175 176 default: 177 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); 178 } 179 180 TMPFS_NODE_LOCK(nnode); 181 TMPFS_LOCK(tmp); 182 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); 183 tmp->tm_nodes_inuse++; 184 TMPFS_UNLOCK(tmp); 185 TMPFS_NODE_UNLOCK(nnode); 186 187 *node = nnode; 188 return 0; 189 } 190 191 /* --------------------------------------------------------------------- */ 192 193 /* 194 * Destroys the node pointed to by node from the file system 'tmp'. 195 * If the node does not belong to the given mount point, the results are 196 * unpredicted. 197 * 198 * If the node references a directory; no entries are allowed because 199 * their removal could need a recursive algorithm, something forbidden in 200 * kernel space. Furthermore, there is not need to provide such 201 * functionality (recursive removal) because the only primitives offered 202 * to the user are the removal of empty directories and the deletion of 203 * individual files. 204 * 205 * Note that nodes are not really deleted; in fact, when a node has been 206 * allocated, it cannot be deleted during the whole life of the file 207 * system. Instead, they are moved to the available list and remain there 208 * until reused. 209 * 210 * A caller must have TMPFS_NODE_LOCK(node) and this function unlocks it. 211 */ 212 void 213 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) 214 { 215 vm_pindex_t pages = 0; 216 217 #ifdef INVARIANTS 218 TMPFS_ASSERT_ELOCKED(node); 219 KKASSERT(node->tn_vnode == NULL); 220 #endif 221 TMPFS_LOCK(tmp); 222 LIST_REMOVE(node, tn_entries); 223 tmp->tm_nodes_inuse--; 224 TMPFS_UNLOCK(tmp); 225 TMPFS_NODE_UNLOCK(node); /* Caller has this lock */ 226 227 switch (node->tn_type) { 228 case VNON: 229 /* Do not do anything. VNON is provided to let the 230 * allocation routine clean itself easily by avoiding 231 * duplicating code in it. */ 232 /* FALLTHROUGH */ 233 case VBLK: 234 /* FALLTHROUGH */ 235 case VCHR: 236 /* FALLTHROUGH */ 237 break; 238 case VDIR: 239 /* 240 * The parent link can be NULL if this is the root 241 * node or if it is a directory node that was rmdir'd. 242 * 243 * XXX what if node is a directory which still contains 244 * directory entries (e.g. due to a forced umount) ? 245 */ 246 node->tn_size = 0; 247 KKASSERT(node->tn_dir.tn_parent == NULL); 248 249 /* 250 * If the root node is being destroyed don't leave a 251 * dangling pointer in tmpfs_mount. 252 */ 253 if (node == tmp->tm_root) 254 tmp->tm_root = NULL; 255 break; 256 case VFIFO: 257 /* FALLTHROUGH */ 258 case VSOCK: 259 break; 260 261 case VLNK: 262 kfree(node->tn_link, tmp->tm_name_zone); 263 node->tn_link = NULL; 264 node->tn_size = 0; 265 break; 266 267 case VREG: 268 if (node->tn_reg.tn_aobj != NULL) 269 vm_object_deallocate(node->tn_reg.tn_aobj); 270 node->tn_reg.tn_aobj = NULL; 271 pages = node->tn_reg.tn_aobj_pages; 272 break; 273 274 default: 275 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); 276 } 277 278 /* 279 * Clean up fields as a safety before destroying the entry. 280 */ 281 tmpfs_node_uninit(node); 282 kfree_obj(node, tmp->tm_node_zone); 283 /* node is now invalid */ 284 285 if (pages) 286 atomic_add_long(&tmp->tm_pages_used, -(long)pages); 287 } 288 289 /* --------------------------------------------------------------------- */ 290 291 /* 292 * Allocates a new directory entry for the node node with a name of name. 293 * The new directory entry is returned in *de. 294 * 295 * The link count of node is increased by one to reflect the new object 296 * referencing it. 297 * 298 * Returns zero on success or an appropriate error code on failure. 299 */ 300 int 301 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 302 const char *name, uint16_t len, struct tmpfs_dirent **de) 303 { 304 struct tmpfs_dirent *nde; 305 306 nde = kmalloc_obj(sizeof(struct tmpfs_dirent), 307 tmp->tm_dirent_zone, M_WAITOK); 308 nde->td_name = kmalloc(len + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK); 309 if (nde->td_name == NULL) { 310 kfree_obj(nde, tmp->tm_dirent_zone); 311 *de = NULL; 312 return (ENOSPC); 313 } 314 nde->td_namelen = len; 315 bcopy(name, nde->td_name, len); 316 nde->td_name[len] = '\0'; 317 318 nde->td_node = node; 319 320 atomic_add_int(&node->tn_links, 1); 321 322 *de = nde; 323 324 return 0; 325 } 326 327 /* --------------------------------------------------------------------- */ 328 329 /* 330 * Frees a directory entry. It is the caller's responsibility to destroy 331 * the node referenced by it if needed. 332 * 333 * The link count of node is decreased by one to reflect the removal of an 334 * object that referenced it. This only happens if 'node_exists' is true; 335 * otherwise the function will not access the node referred to by the 336 * directory entry, as it may already have been released from the outside. 337 */ 338 void 339 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de) 340 { 341 struct tmpfs_node *node; 342 343 node = de->td_node; 344 345 KKASSERT(node->tn_links > 0); 346 atomic_add_int(&node->tn_links, -1); 347 348 kfree(de->td_name, tmp->tm_name_zone); 349 de->td_namelen = 0; 350 de->td_name = NULL; 351 de->td_node = NULL; 352 kfree_obj(de, tmp->tm_dirent_zone); 353 } 354 355 /* --------------------------------------------------------------------- */ 356 357 /* 358 * Allocates a new vnode for the node node or returns a new reference to 359 * an existing one if the node had already a vnode referencing it. The 360 * resulting locked vnode is returned in *vpp. 361 * 362 * Returns zero on success or an appropriate error code on failure. 363 * 364 * The caller must ensure that node cannot go away (usually by holding 365 * the related directory entry). 366 * 367 * If dnode is non-NULL this routine avoids deadlocking against it but 368 * can return EAGAIN. Caller must try again. The dnode lock will cycle 369 * in this case, it remains locked on return in all cases. dnode must 370 * be shared-locked. 371 */ 372 int 373 tmpfs_alloc_vp(struct mount *mp, 374 struct tmpfs_node *dnode, struct tmpfs_node *node, int lkflag, 375 struct vnode **vpp) 376 { 377 int error = 0; 378 struct vnode *vp; 379 380 loop: 381 vp = NULL; 382 if (node->tn_vnode == NULL) { 383 error = getnewvnode(VT_TMPFS, mp, &vp, 384 VLKTIMEOUT, LK_CANRECURSE); 385 if (error) 386 goto out; 387 } 388 389 /* 390 * Interlocked extraction from node. This can race many things. 391 * We have to get a soft reference on the vnode while we hold 392 * the node locked, then acquire it properly and check for races. 393 */ 394 TMPFS_NODE_LOCK(node); 395 if (node->tn_vnode) { 396 if (vp) { 397 vp->v_type = VBAD; 398 vx_put(vp); 399 } 400 vp = node->tn_vnode; 401 402 KKASSERT((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); 403 vhold(vp); 404 TMPFS_NODE_UNLOCK(node); 405 406 if (dnode) { 407 /* 408 * Special-case handling to avoid deadlocking against 409 * dnode. This case has been validated and occurs 410 * every so often during synth builds and in other 411 * situations. 412 */ 413 if (vget(vp, (lkflag & ~LK_RETRY) | 414 LK_NOWAIT | 415 LK_EXCLUSIVE) != 0) 416 { 417 TMPFS_NODE_UNLOCK(dnode); 418 if (vget(vp, (lkflag & ~LK_RETRY) | 419 LK_SLEEPFAIL | 420 LK_EXCLUSIVE) == 0) { 421 vput(vp); 422 } 423 vdrop(vp); 424 TMPFS_NODE_LOCK_SH(dnode); 425 426 return EAGAIN; 427 } 428 } else { 429 /* 430 * Normal path 431 */ 432 if (vget(vp, lkflag | LK_EXCLUSIVE) != 0) { 433 vdrop(vp); 434 goto loop; 435 } 436 } 437 if (node->tn_vnode != vp) { 438 vput(vp); 439 vdrop(vp); 440 goto loop; 441 } 442 vdrop(vp); 443 goto out; 444 } 445 446 /* 447 * We need to assign node->tn_vnode. If vp is NULL, loop up to 448 * allocate the vp. This can happen due to SMP races. 449 */ 450 if (vp == NULL) { 451 TMPFS_NODE_UNLOCK(node); 452 goto loop; 453 } 454 455 /* 456 * This should never happen. 457 */ 458 if (node->tn_vpstate & TMPFS_VNODE_DOOMED) { 459 TMPFS_NODE_UNLOCK(node); 460 vp->v_type = VBAD; 461 vx_put(vp); 462 error = ENOENT; 463 goto out; 464 } 465 466 KKASSERT(node->tn_vnode == NULL); 467 KKASSERT(vp != NULL); 468 vp->v_data = node; 469 vp->v_type = node->tn_type; 470 471 /* Type-specific initialization. */ 472 switch (node->tn_type) { 473 case VBLK: 474 /* FALLTHROUGH */ 475 case VCHR: 476 /* FALLTHROUGH */ 477 case VSOCK: 478 break; 479 case VREG: 480 /* 481 * VMIO is mandatory. Tmpfs also supports KVABIO 482 * for its tmpfs_strategy(). 483 */ 484 vsetflags(vp, VKVABIO); 485 vinitvmio(vp, node->tn_size, node->tn_blksize, -1); 486 break; 487 case VLNK: 488 break; 489 case VFIFO: 490 vp->v_ops = &mp->mnt_vn_fifo_ops; 491 break; 492 case VDIR: 493 break; 494 495 default: 496 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); 497 } 498 499 node->tn_vnode = vp; 500 TMPFS_NODE_UNLOCK(node); 501 502 vx_downgrade(vp); 503 out: 504 *vpp = vp; 505 KKASSERT(IFF(error == 0, *vpp != NULL && vn_islocked(*vpp))); 506 507 return error; 508 } 509 510 /* --------------------------------------------------------------------- */ 511 512 /* 513 * Allocates a new file of type 'type' and adds it to the parent directory 514 * 'dvp'; this addition is done using the component name given in 'cnp'. 515 * The ownership of the new file is automatically assigned based on the 516 * credentials of the caller (through 'cnp'), the group is set based on 517 * the parent directory and the mode is determined from the 'vap' argument. 518 * If successful, *vpp holds a vnode to the newly created file and zero 519 * is returned. Otherwise *vpp is NULL and the function returns an 520 * appropriate error code. 521 */ 522 int 523 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 524 struct namecache *ncp, struct ucred *cred, char *target) 525 { 526 int error; 527 struct tmpfs_dirent *de; 528 struct tmpfs_mount *tmp; 529 struct tmpfs_node *dnode; 530 struct tmpfs_node *node; 531 532 tmp = VFS_TO_TMPFS(dvp->v_mount); 533 dnode = VP_TO_TMPFS_DIR(dvp); 534 *vpp = NULL; 535 536 TMPFS_NODE_LOCK(dnode); 537 538 /* 539 * If the directory was removed but a process was CD'd into it, 540 * we do not allow any more file/dir creation within it. Otherwise 541 * we will lose track of it. 542 */ 543 KKASSERT(dnode->tn_type == VDIR); 544 if (dnode != tmp->tm_root && dnode->tn_dir.tn_parent == NULL) { 545 TMPFS_NODE_UNLOCK(dnode); 546 return ENOENT; 547 } 548 549 /* 550 * Make sure the link count does not overflow. 551 */ 552 if (vap->va_type == VDIR && dnode->tn_links >= LINK_MAX) { 553 TMPFS_NODE_UNLOCK(dnode); 554 return EMLINK; 555 } 556 557 /* Allocate a node that represents the new file. */ 558 error = tmpfs_alloc_node(tmp, vap->va_type, cred->cr_uid, 559 dnode->tn_gid, vap->va_mode, target, 560 vap->va_rmajor, vap->va_rminor, &node); 561 if (error != 0) { 562 TMPFS_NODE_UNLOCK(dnode); 563 return error; 564 } 565 TMPFS_NODE_LOCK(node); 566 567 /* Allocate a directory entry that points to the new file. */ 568 error = tmpfs_alloc_dirent(tmp, node, ncp->nc_name, ncp->nc_nlen, &de); 569 if (error != 0) { 570 TMPFS_NODE_UNLOCK(dnode); 571 tmpfs_free_node(tmp, node); 572 /* eats node lock */ 573 return error; 574 } 575 576 /* Allocate a vnode for the new file. */ 577 error = tmpfs_alloc_vp(dvp->v_mount, NULL, node, LK_EXCLUSIVE, vpp); 578 if (error != 0) { 579 TMPFS_NODE_UNLOCK(dnode); 580 tmpfs_free_dirent(tmp, de); 581 tmpfs_free_node(tmp, node); 582 /* eats node lock */ 583 return error; 584 } 585 586 /* 587 * Now that all required items are allocated, we can proceed to 588 * insert the new node into the directory, an operation that 589 * cannot fail. 590 */ 591 tmpfs_dir_attach_locked(dnode, de); 592 TMPFS_NODE_UNLOCK(dnode); 593 TMPFS_NODE_UNLOCK(node); 594 595 return error; 596 } 597 598 /* --------------------------------------------------------------------- */ 599 600 /* 601 * Attaches the directory entry de to the directory represented by dnode. 602 * Note that this does not change the link count of the node pointed by 603 * the directory entry, as this is done by tmpfs_alloc_dirent. 604 * 605 * dnode must be locked. 606 */ 607 void 608 tmpfs_dir_attach_locked(struct tmpfs_node *dnode, struct tmpfs_dirent *de) 609 { 610 struct tmpfs_node *node = de->td_node; 611 struct tmpfs_dirent *de2; 612 613 if (node && node->tn_type == VDIR) { 614 TMPFS_NODE_LOCK(node); 615 atomic_add_int(&node->tn_links, 1); 616 node->tn_status |= TMPFS_NODE_CHANGED; 617 node->tn_dir.tn_parent = dnode; 618 atomic_add_int(&dnode->tn_links, 1); 619 TMPFS_NODE_UNLOCK(node); 620 } 621 de2 = RB_INSERT(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de); 622 KASSERT(de2 == NULL, 623 ("tmpfs_dir_attach_lockedA: duplicate insertion of %p, has %p\n", 624 de, de2)); 625 de2 = RB_INSERT(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de); 626 KASSERT(de2 == NULL, 627 ("tmpfs_dir_attach_lockedB: duplicate insertion of %p, has %p\n", 628 de, de2)); 629 dnode->tn_size += sizeof(struct tmpfs_dirent); 630 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | 631 TMPFS_NODE_MODIFIED; 632 } 633 634 /* --------------------------------------------------------------------- */ 635 636 /* 637 * Detaches the directory entry de from the directory represented by dnode. 638 * Note that this does not change the link count of the node pointed by 639 * the directory entry, as this is done by tmpfs_free_dirent. 640 * 641 * dnode must be locked. 642 */ 643 void 644 tmpfs_dir_detach_locked(struct tmpfs_node *dnode, struct tmpfs_dirent *de) 645 { 646 struct tmpfs_node *node = de->td_node; 647 648 RB_REMOVE(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de); 649 RB_REMOVE(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de); 650 dnode->tn_size -= sizeof(struct tmpfs_dirent); 651 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | 652 TMPFS_NODE_MODIFIED; 653 654 /* 655 * Clean out the tn_parent pointer immediately when removing a 656 * directory. 657 * 658 * Removal of the parent linkage also cleans out the extra tn_links 659 * count we had on both node and dnode. 660 * 661 * node can be NULL (typ during a forced umount), in which case 662 * the mount code is dealing with the linkages from a linked list 663 * scan. 664 */ 665 if (node && node->tn_type == VDIR && node->tn_dir.tn_parent) { 666 TMPFS_NODE_LOCK(node); 667 KKASSERT(node->tn_dir.tn_parent == dnode); 668 atomic_add_int(&dnode->tn_links, -1); 669 atomic_add_int(&node->tn_links, -1); 670 node->tn_dir.tn_parent = NULL; 671 TMPFS_NODE_UNLOCK(node); 672 } 673 } 674 675 /* --------------------------------------------------------------------- */ 676 677 /* 678 * Looks for a directory entry in the directory represented by node. 679 * 'ncp' describes the name of the entry to look for. Note that the . 680 * and .. components are not allowed as they do not physically exist 681 * within directories. 682 * 683 * Returns a pointer to the entry when found, otherwise NULL. 684 * 685 * Caller must hold the node locked (shared ok) 686 */ 687 struct tmpfs_dirent * 688 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, 689 struct namecache *ncp) 690 { 691 struct tmpfs_dirent *de; 692 int len = ncp->nc_nlen; 693 struct tmpfs_dirent wanted; 694 695 wanted.td_namelen = len; 696 wanted.td_name = ncp->nc_name; 697 698 TMPFS_VALIDATE_DIR(node); 699 700 de = RB_FIND(tmpfs_dirtree, &node->tn_dir.tn_dirtree, &wanted); 701 702 KASSERT((f == NULL || de == NULL || f == de->td_node), 703 ("tmpfs_dir_lookup: Incorrect node %p %p %p", 704 f, de, (de ? de->td_node : NULL))); 705 706 return de; 707 } 708 709 /* --------------------------------------------------------------------- */ 710 711 /* 712 * Helper function for tmpfs_readdir. Creates a '.' entry for the given 713 * directory and returns it in the uio space. The function returns 0 714 * on success, -1 if there was not enough space in the uio structure to 715 * hold the directory entry or an appropriate error code if another 716 * error happens. 717 */ 718 int 719 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) 720 { 721 int error; 722 723 TMPFS_VALIDATE_DIR(node); 724 KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); 725 726 if (vop_write_dirent(&error, uio, node->tn_id, DT_DIR, 1, ".")) 727 return -1; 728 if (error == 0) 729 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 730 return error; 731 } 732 733 /* --------------------------------------------------------------------- */ 734 735 /* 736 * Helper function for tmpfs_readdir. Creates a '..' entry for the given 737 * directory and returns it in the uio space. The function returns 0 738 * on success, -1 if there was not enough space in the uio structure to 739 * hold the directory entry or an appropriate error code if another 740 * error happens. 741 */ 742 int 743 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 744 struct uio *uio) 745 { 746 int error; 747 ino_t d_ino; 748 749 TMPFS_VALIDATE_DIR(node); 750 KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); 751 752 if (node->tn_dir.tn_parent) { 753 TMPFS_NODE_LOCK(node); 754 if (node->tn_dir.tn_parent) 755 d_ino = node->tn_dir.tn_parent->tn_id; 756 else 757 d_ino = tmp->tm_root->tn_id; 758 TMPFS_NODE_UNLOCK(node); 759 } else { 760 d_ino = tmp->tm_root->tn_id; 761 } 762 763 if (vop_write_dirent(&error, uio, d_ino, DT_DIR, 2, "..")) 764 return -1; 765 if (error == 0) { 766 struct tmpfs_dirent *de; 767 de = RB_MIN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree); 768 if (de == NULL) 769 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 770 else 771 uio->uio_offset = tmpfs_dircookie(de); 772 } 773 return error; 774 } 775 776 /* --------------------------------------------------------------------- */ 777 778 /* 779 * Lookup a directory entry by its associated cookie. 780 * 781 * Must be called with the directory node locked (shared ok) 782 */ 783 #if 0 784 785 struct lubycookie_info { 786 off_t cookie; 787 struct tmpfs_dirent *de; 788 }; 789 790 static int 791 lubycookie_cmp(struct tmpfs_dirent *de, void *arg) 792 { 793 struct lubycookie_info *info = arg; 794 off_t cookie = tmpfs_dircookie(de); 795 796 if (cookie < info->cookie) 797 return(-1); 798 if (cookie > info->cookie) 799 return(1); 800 return(0); 801 } 802 803 static int 804 lubycookie_callback(struct tmpfs_dirent *de, void *arg) 805 { 806 struct lubycookie_info *info = arg; 807 808 if (tmpfs_dircookie(de) == info->cookie) { 809 info->de = de; 810 return(-1); 811 } 812 return(0); 813 } 814 815 #endif 816 817 /* 818 * Find first cookie >= (cookie). If exact specified, find the exact 819 * cookie. 820 */ 821 struct tmpfs_dirent * 822 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie, int exact) 823 { 824 #if 0 825 struct lubycookie_info info; 826 827 info.cookie = cookie; 828 info.de = NULL; 829 RB_SCAN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree, 830 lubycookie_cmp, lubycookie_callback, &info); 831 return (info.de); 832 #endif 833 struct tmpfs_dirent *cdent = tmpfs_cookiedir(cookie); 834 struct tmpfs_dirent *last; 835 struct tmpfs_dirent *tmp; 836 837 last = NULL; 838 tmp = RB_ROOT(&node->tn_dir.tn_cookietree); 839 while (tmp) { 840 if (cdent == tmp) 841 return cdent; 842 if (cdent > tmp) { 843 last = tmp; 844 tmp = RB_RIGHT(tmp, rb_cookienode); 845 } else { 846 tmp = RB_LEFT(tmp, rb_cookienode); 847 } 848 } 849 return (exact ? NULL : last); 850 } 851 852 /* --------------------------------------------------------------------- */ 853 854 /* 855 * Helper function for tmpfs_readdir. Returns as much directory entries 856 * as can fit in the uio space. The read starts at uio->uio_offset. 857 * The function returns 0 on success, -1 if there was not enough space 858 * in the uio structure to hold the directory entry or an appropriate 859 * error code if another error happens. 860 * 861 * Caller must hold the node locked (shared ok) 862 */ 863 int 864 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp) 865 { 866 int error; 867 off_t startcookie; 868 struct tmpfs_dirent *de; 869 870 TMPFS_VALIDATE_DIR(node); 871 872 /* 873 * Locate the first directory entry we have to return. We have cached 874 * the last readdir in the node, so use those values if appropriate. 875 * Otherwise do a linear scan to find the requested entry. 876 * 877 * If a particular cookie does not exist, locate the first valid 878 * cookie after that one. 879 */ 880 startcookie = uio->uio_offset; 881 KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOT); 882 KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT); 883 884 if (startcookie == TMPFS_DIRCOOKIE_EOF) 885 return 0; 886 887 /* 888 * Inexact lookup, find first direntry with a cookie >= startcookie. 889 * If none found we are at the EOF. 890 */ 891 de = tmpfs_dir_lookupbycookie(node, startcookie, 0); 892 if (de == NULL) { 893 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 894 return 0; 895 } 896 897 /* 898 * Read as much entries as possible; i.e., until we reach the end of 899 * the directory or we exhaust uio space. 900 */ 901 do { 902 ino_t d_ino; 903 uint8_t d_type; 904 905 /* Create a dirent structure representing the current 906 * tmpfs_node and fill it. */ 907 d_ino = de->td_node->tn_id; 908 switch (de->td_node->tn_type) { 909 case VBLK: 910 d_type = DT_BLK; 911 break; 912 913 case VCHR: 914 d_type = DT_CHR; 915 break; 916 917 case VDIR: 918 d_type = DT_DIR; 919 break; 920 921 case VFIFO: 922 d_type = DT_FIFO; 923 break; 924 925 case VLNK: 926 d_type = DT_LNK; 927 break; 928 929 case VREG: 930 d_type = DT_REG; 931 break; 932 933 case VSOCK: 934 d_type = DT_SOCK; 935 break; 936 937 default: 938 panic("tmpfs_dir_getdents: type %p %d", 939 de->td_node, (int)de->td_node->tn_type); 940 } 941 KKASSERT(de->td_namelen < 256); /* 255 + 1 */ 942 943 if (vop_write_dirent(&error, uio, d_ino, d_type, 944 de->td_namelen, de->td_name)) { 945 error = -1; 946 break; 947 } 948 949 (*cntp)++; 950 de = RB_NEXT(tmpfs_dirtree_cookie, 951 node->tn_dir.tn_cookietree, de); 952 } while (error == 0 && uio->uio_resid > 0 && de != NULL); 953 954 /* Update the offset and cache. */ 955 if (de == NULL) { 956 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 957 } else { 958 uio->uio_offset = tmpfs_dircookie(de); 959 } 960 961 return error; 962 } 963 964 /* --------------------------------------------------------------------- */ 965 966 /* 967 * Resizes the aobj associated to the regular file pointed to by vp to 968 * the size newsize. 'vp' must point to a vnode that represents a regular 969 * file. 'newsize' must be positive. 970 * 971 * pass NVEXTF_TRIVIAL when buf content will be overwritten, otherwise set 0 972 * to be zero filled. 973 * 974 * Returns zero on success or an appropriate error code on failure. 975 * 976 * Caller must hold the node exclusively locked. 977 */ 978 int 979 tmpfs_reg_resize(struct vnode *vp, off_t newsize, int trivial) 980 { 981 int error; 982 vm_pindex_t newpages, oldpages; 983 struct tmpfs_mount *tmp; 984 struct tmpfs_node *node; 985 off_t oldsize; 986 int nvextflags; 987 988 #ifdef INVARIANTS 989 KKASSERT(vp->v_type == VREG); 990 KKASSERT(newsize >= 0); 991 #endif 992 993 node = VP_TO_TMPFS_NODE(vp); 994 tmp = VFS_TO_TMPFS(vp->v_mount); 995 996 /* 997 * Convert the old and new sizes to the number of pages needed to 998 * store them. It may happen that we do not need to do anything 999 * because the last allocated page can accommodate the change on 1000 * its own. 1001 */ 1002 oldsize = node->tn_size; 1003 oldpages = round_page64(oldsize) / PAGE_SIZE; 1004 KKASSERT(oldpages == node->tn_reg.tn_aobj_pages); 1005 newpages = round_page64(newsize) / PAGE_SIZE; 1006 1007 if (newpages > oldpages && 1008 tmp->tm_pages_used + newpages - oldpages > tmp->tm_pages_max) { 1009 error = ENOSPC; 1010 goto out; 1011 } 1012 node->tn_reg.tn_aobj_pages = newpages; 1013 node->tn_size = newsize; 1014 1015 if (newpages != oldpages) 1016 atomic_add_long(&tmp->tm_pages_used, (newpages - oldpages)); 1017 1018 /* 1019 * nvextflags to pass along for bdwrite() vs buwrite(), this is 1020 * so tmpfs activity doesn't eat memory being freed by the pageout 1021 * daemon. 1022 */ 1023 if (vm_pages_needed || vm_paging_start(0) || 1024 tmpfs_bufcache_mode >= 2) { 1025 nvextflags = 0; 1026 } else { 1027 nvextflags = NVEXTF_BUWRITE; 1028 } 1029 1030 1031 /* 1032 * When adjusting the vnode filesize and its VM object we must 1033 * also adjust our backing VM object (aobj). The blocksize 1034 * used must match the block sized we use for the buffer cache. 1035 * 1036 * The backing VM object may contain VM pages as well as swap 1037 * assignments if we previously renamed main object pages into 1038 * it during deactivation. 1039 * 1040 * To make things easier tmpfs uses a blksize in multiples of 1041 * PAGE_SIZE, and will only increase the blksize as a small file 1042 * increases in size. Once a file has exceeded TMPFS_BLKSIZE (16KB), 1043 * the blksize is maxed out. Truncating the file does not reduce 1044 * the blksize. 1045 */ 1046 if (newsize < oldsize) { 1047 vm_pindex_t osize; 1048 vm_pindex_t nsize; 1049 vm_object_t aobj; 1050 1051 error = nvtruncbuf(vp, newsize, node->tn_blksize, 1052 -1, nvextflags); 1053 aobj = node->tn_reg.tn_aobj; 1054 if (aobj) { 1055 osize = aobj->size; 1056 nsize = vp->v_object->size; 1057 if (nsize < osize) { 1058 aobj->size = osize; 1059 swap_pager_freespace(aobj, nsize, 1060 osize - nsize); 1061 vm_object_page_remove(aobj, nsize, osize, 1062 FALSE); 1063 } 1064 } 1065 } else { 1066 vm_object_t aobj; 1067 int nblksize; 1068 1069 /* 1070 * The first (and only the first) buffer in the file is resized 1071 * in multiples of PAGE_SIZE, up to TMPFS_BLKSIZE. 1072 */ 1073 nblksize = node->tn_blksize; 1074 while (nblksize < TMPFS_BLKSIZE && 1075 nblksize < newsize) { 1076 nblksize += PAGE_SIZE; 1077 } 1078 1079 if (trivial) 1080 nvextflags |= NVEXTF_TRIVIAL; 1081 1082 error = nvextendbuf(vp, oldsize, newsize, 1083 node->tn_blksize, nblksize, 1084 -1, -1, nvextflags); 1085 node->tn_blksize = nblksize; 1086 aobj = node->tn_reg.tn_aobj; 1087 if (aobj) 1088 aobj->size = vp->v_object->size; 1089 } 1090 1091 out: 1092 return error; 1093 } 1094 1095 /* --------------------------------------------------------------------- */ 1096 1097 /* 1098 * Change flags of the given vnode. 1099 * Caller should execute tmpfs_update on vp after a successful execution. 1100 * The vnode must be locked on entry and remain locked on exit. 1101 */ 1102 int 1103 tmpfs_chflags(struct vnode *vp, u_long vaflags, struct ucred *cred) 1104 { 1105 int error; 1106 struct tmpfs_node *node; 1107 int flags; 1108 1109 KKASSERT(vn_islocked(vp)); 1110 1111 node = VP_TO_TMPFS_NODE(vp); 1112 flags = node->tn_flags; 1113 1114 /* Disallow this operation if the file system is mounted read-only. */ 1115 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1116 return EROFS; 1117 error = vop_helper_setattr_flags(&flags, vaflags, node->tn_uid, cred); 1118 1119 /* Actually change the flags on the node itself */ 1120 if (error == 0) { 1121 TMPFS_NODE_LOCK(node); 1122 node->tn_flags = flags; 1123 node->tn_status |= TMPFS_NODE_CHANGED; 1124 TMPFS_NODE_UNLOCK(node); 1125 } 1126 1127 KKASSERT(vn_islocked(vp)); 1128 1129 return error; 1130 } 1131 1132 /* --------------------------------------------------------------------- */ 1133 1134 /* 1135 * Change access mode on the given vnode. 1136 * Caller should execute tmpfs_update on vp after a successful execution. 1137 * The vnode must be locked on entry and remain locked on exit. 1138 */ 1139 int 1140 tmpfs_chmod(struct vnode *vp, mode_t vamode, struct ucred *cred) 1141 { 1142 struct tmpfs_node *node; 1143 mode_t cur_mode; 1144 int error; 1145 1146 KKASSERT(vn_islocked(vp)); 1147 1148 node = VP_TO_TMPFS_NODE(vp); 1149 1150 /* Disallow this operation if the file system is mounted read-only. */ 1151 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1152 return EROFS; 1153 1154 /* Immutable or append-only files cannot be modified, either. */ 1155 if (node->tn_flags & (IMMUTABLE | APPEND)) 1156 return EPERM; 1157 1158 cur_mode = node->tn_mode; 1159 error = vop_helper_chmod(vp, vamode, cred, node->tn_uid, node->tn_gid, 1160 &cur_mode); 1161 1162 if (error == 0 && 1163 (node->tn_mode & ALLPERMS) != (cur_mode & ALLPERMS)) { 1164 TMPFS_NODE_LOCK(node); 1165 node->tn_mode &= ~ALLPERMS; 1166 node->tn_mode |= cur_mode & ALLPERMS; 1167 1168 node->tn_status |= TMPFS_NODE_CHANGED; 1169 TMPFS_NODE_UNLOCK(node); 1170 } 1171 1172 KKASSERT(vn_islocked(vp)); 1173 1174 return 0; 1175 } 1176 1177 /* --------------------------------------------------------------------- */ 1178 1179 /* 1180 * Change ownership of the given vnode. At least one of uid or gid must 1181 * be different than VNOVAL. If one is set to that value, the attribute 1182 * is unchanged. 1183 * Caller should execute tmpfs_update on vp after a successful execution. 1184 * The vnode must be locked on entry and remain locked on exit. 1185 */ 1186 int 1187 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred) 1188 { 1189 mode_t cur_mode; 1190 uid_t cur_uid; 1191 gid_t cur_gid; 1192 struct tmpfs_node *node; 1193 int error; 1194 1195 KKASSERT(vn_islocked(vp)); 1196 node = VP_TO_TMPFS_NODE(vp); 1197 1198 /* Disallow this operation if the file system is mounted read-only. */ 1199 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1200 return EROFS; 1201 1202 /* Immutable or append-only files cannot be modified, either. */ 1203 if (node->tn_flags & (IMMUTABLE | APPEND)) 1204 return EPERM; 1205 1206 cur_uid = node->tn_uid; 1207 cur_gid = node->tn_gid; 1208 cur_mode = node->tn_mode; 1209 error = vop_helper_chown(vp, uid, gid, cred, 1210 &cur_uid, &cur_gid, &cur_mode); 1211 1212 if (error == 0) { 1213 TMPFS_NODE_LOCK(node); 1214 if (cur_uid != node->tn_uid || 1215 cur_gid != node->tn_gid || 1216 cur_mode != node->tn_mode) { 1217 node->tn_uid = cur_uid; 1218 node->tn_gid = cur_gid; 1219 node->tn_mode = cur_mode; 1220 node->tn_status |= TMPFS_NODE_CHANGED; 1221 } 1222 TMPFS_NODE_UNLOCK(node); 1223 } 1224 1225 return error; 1226 } 1227 1228 /* --------------------------------------------------------------------- */ 1229 1230 /* 1231 * Change size of the given vnode. 1232 * Caller should execute tmpfs_update on vp after a successful execution. 1233 * The vnode must be locked on entry and remain locked on exit. 1234 */ 1235 int 1236 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred) 1237 { 1238 int error; 1239 struct tmpfs_node *node; 1240 1241 KKASSERT(vn_islocked(vp)); 1242 1243 node = VP_TO_TMPFS_NODE(vp); 1244 1245 /* Decide whether this is a valid operation based on the file type. */ 1246 error = 0; 1247 switch (vp->v_type) { 1248 case VDIR: 1249 return EISDIR; 1250 1251 case VREG: 1252 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1253 return EROFS; 1254 break; 1255 1256 case VBLK: 1257 /* FALLTHROUGH */ 1258 case VCHR: 1259 /* FALLTHROUGH */ 1260 case VFIFO: 1261 /* Allow modifications of special files even if in the file 1262 * system is mounted read-only (we are not modifying the 1263 * files themselves, but the objects they represent). */ 1264 return 0; 1265 1266 default: 1267 /* Anything else is unsupported. */ 1268 return EOPNOTSUPP; 1269 } 1270 1271 /* Immutable or append-only files cannot be modified, either. */ 1272 if (node->tn_flags & (IMMUTABLE | APPEND)) 1273 return EPERM; 1274 1275 error = tmpfs_truncate(vp, size); 1276 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents 1277 * for us, as will update tn_status; no need to do that here. */ 1278 1279 KKASSERT(vn_islocked(vp)); 1280 1281 return error; 1282 } 1283 1284 /* --------------------------------------------------------------------- */ 1285 1286 /* 1287 * Change access and modification times of the given vnode. 1288 * Caller should execute tmpfs_update on vp after a successful execution. 1289 * The vnode must be locked on entry and remain locked on exit. 1290 */ 1291 int 1292 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime, 1293 int vaflags, struct ucred *cred) 1294 { 1295 struct tmpfs_node *node; 1296 1297 KKASSERT(vn_islocked(vp)); 1298 1299 node = VP_TO_TMPFS_NODE(vp); 1300 1301 /* Disallow this operation if the file system is mounted read-only. */ 1302 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1303 return EROFS; 1304 1305 /* Immutable or append-only files cannot be modified, either. */ 1306 if (node->tn_flags & (IMMUTABLE | APPEND)) 1307 return EPERM; 1308 1309 TMPFS_NODE_LOCK(node); 1310 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL) 1311 node->tn_status |= TMPFS_NODE_ACCESSED; 1312 1313 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) { 1314 node->tn_status |= TMPFS_NODE_MODIFIED; 1315 vclrflags(vp, VLASTWRITETS); 1316 } 1317 1318 TMPFS_NODE_UNLOCK(node); 1319 1320 tmpfs_itimes(vp, atime, mtime); 1321 1322 KKASSERT(vn_islocked(vp)); 1323 1324 return 0; 1325 } 1326 1327 /* --------------------------------------------------------------------- */ 1328 /* Sync timestamps */ 1329 void 1330 tmpfs_itimes(struct vnode *vp, const struct timespec *acc, 1331 const struct timespec *mod) 1332 { 1333 struct tmpfs_node *node; 1334 struct timespec now; 1335 1336 node = VP_TO_TMPFS_NODE(vp); 1337 1338 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1339 TMPFS_NODE_CHANGED)) == 0) { 1340 return; 1341 } 1342 1343 vfs_timestamp(&now); 1344 1345 TMPFS_NODE_LOCK(node); 1346 if (node->tn_status & TMPFS_NODE_ACCESSED) { 1347 if (acc == NULL) 1348 acc = &now; 1349 node->tn_atime = acc->tv_sec; 1350 node->tn_atimensec = acc->tv_nsec; 1351 } 1352 if (node->tn_status & TMPFS_NODE_MODIFIED) { 1353 if (mod == NULL) 1354 mod = &now; 1355 node->tn_mtime = mod->tv_sec; 1356 node->tn_mtimensec = mod->tv_nsec; 1357 } 1358 if (node->tn_status & TMPFS_NODE_CHANGED) { 1359 node->tn_ctime = now.tv_sec; 1360 node->tn_ctimensec = now.tv_nsec; 1361 } 1362 1363 node->tn_status &= ~(TMPFS_NODE_ACCESSED | 1364 TMPFS_NODE_MODIFIED | 1365 TMPFS_NODE_CHANGED); 1366 TMPFS_NODE_UNLOCK(node); 1367 } 1368 1369 /* --------------------------------------------------------------------- */ 1370 1371 void 1372 tmpfs_update(struct vnode *vp) 1373 { 1374 tmpfs_itimes(vp, NULL, NULL); 1375 } 1376 1377 /* --------------------------------------------------------------------- */ 1378 1379 /* 1380 * Caller must hold an exclusive node lock. 1381 */ 1382 int 1383 tmpfs_truncate(struct vnode *vp, off_t length) 1384 { 1385 int error; 1386 struct tmpfs_node *node; 1387 1388 node = VP_TO_TMPFS_NODE(vp); 1389 1390 if (length < 0) { 1391 error = EINVAL; 1392 goto out; 1393 } 1394 1395 if (node->tn_size == length) { 1396 error = 0; 1397 goto out; 1398 } 1399 1400 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) 1401 return (EFBIG); 1402 1403 1404 error = tmpfs_reg_resize(vp, length, 1); 1405 1406 if (error == 0) 1407 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; 1408 1409 out: 1410 tmpfs_update(vp); 1411 1412 return error; 1413 } 1414 1415 /* --------------------------------------------------------------------- */ 1416 1417 static ino_t 1418 tmpfs_fetch_ino(struct tmpfs_mount *tmp) 1419 { 1420 ino_t ret; 1421 1422 ret = atomic_fetchadd_64(&tmp->tm_ino, 1); 1423 1424 return (ret); 1425 } 1426 1427 static int 1428 tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b) 1429 { 1430 if (a->td_namelen > b->td_namelen) 1431 return 1; 1432 else if (a->td_namelen < b->td_namelen) 1433 return -1; 1434 else 1435 return strncmp(a->td_name, b->td_name, a->td_namelen); 1436 } 1437 1438 static int 1439 tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b) 1440 { 1441 if (a < b) 1442 return(-1); 1443 if (a > b) 1444 return(1); 1445 return 0; 1446 } 1447 1448 /* 1449 * Lock for rename. The namecache entries for the related terminal files 1450 * are already locked but the directories are not. A directory lock order 1451 * reversal is possible so use a deterministic order. 1452 * 1453 * Generally order path parent-to-child or using a simple pointer comparison. 1454 * Probably not perfect but it should catch most of the cases. 1455 * 1456 * Underlying files must be locked after the related directory. 1457 */ 1458 void 1459 tmpfs_lock4(struct tmpfs_node *node1, struct tmpfs_node *node2, 1460 struct tmpfs_node *node3, struct tmpfs_node *node4) 1461 { 1462 if (node1->tn_dir.tn_parent != node2 && 1463 (node1 < node2 || node2->tn_dir.tn_parent == node1)) { 1464 TMPFS_NODE_LOCK(node1); /* fdir */ 1465 TMPFS_NODE_LOCK(node3); /* ffile */ 1466 TMPFS_NODE_LOCK(node2); /* tdir */ 1467 if (node4) 1468 TMPFS_NODE_LOCK(node4); /* tfile */ 1469 } else { 1470 TMPFS_NODE_LOCK(node2); /* tdir */ 1471 if (node4) 1472 TMPFS_NODE_LOCK(node4); /* tfile */ 1473 TMPFS_NODE_LOCK(node1); /* fdir */ 1474 TMPFS_NODE_LOCK(node3); /* ffile */ 1475 } 1476 } 1477 1478 void 1479 tmpfs_unlock4(struct tmpfs_node *node1, struct tmpfs_node *node2, 1480 struct tmpfs_node *node3, struct tmpfs_node *node4) 1481 { 1482 if (node4) 1483 TMPFS_NODE_UNLOCK(node4); 1484 TMPFS_NODE_UNLOCK(node2); 1485 TMPFS_NODE_UNLOCK(node3); 1486 TMPFS_NODE_UNLOCK(node1); 1487 } 1488