1 /* $OpenBSD: tmpfs_subr.c,v 1.26 2022/11/15 17:16:44 mvs Exp $ */ 2 /* $NetBSD: tmpfs_subr.c,v 1.79 2012/03/13 18:40:50 elad Exp $ */ 3 4 /* 5 * Copyright (c) 2005-2011 The NetBSD Foundation, Inc. 6 * Copyright (c) 2013 Pedro Martelletto 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to The NetBSD Foundation 10 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code 11 * 2005 program, and by Mindaugas Rasiukevicius. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Efficient memory file system: interfaces for inode and directory entry 37 * construction, destruction and manipulation. 38 * 39 * Reference counting 40 * 41 * The link count of inode (tmpfs_node_t::tn_links) is used as a 42 * reference counter. However, it has slightly different semantics. 43 * 44 * For directories - link count represents directory entries, which 45 * refer to the directories. In other words, it represents the count 46 * of sub-directories. It also takes into account the virtual '.' 47 * entry (which has no real entry in the list). For files - link count 48 * represents the hard links. Since only empty directories can be 49 * removed - link count aligns the reference counting requirements 50 * enough. Note: to check whether directory is not empty, the inode 51 * size (tmpfs_node_t::tn_size) can be used. 52 * 53 * The inode itself, as an object, gathers its first reference when 54 * directory entry is attached via tmpfs_dir_attach(9). For instance, 55 * after regular tmpfs_create(), a file would have a link count of 1, 56 * while directory after tmpfs_mkdir() would have 2 (due to '.'). 57 * 58 * Reclamation 59 * 60 * It should be noted that tmpfs inodes rely on a combination of vnode 61 * reference counting and link counting. That is, an inode can only be 62 * destroyed if its associated vnode is inactive. The destruction is 63 * done on vnode reclamation i.e. tmpfs_reclaim(). It should be noted 64 * that tmpfs_node_t::tn_links being 0 is a destruction criterion. 65 * 66 * If an inode has references within the file system (tn_links > 0) and 67 * its inactive vnode gets reclaimed/recycled - then the association is 68 * broken in tmpfs_reclaim(). In such case, an inode will always pass 69 * tmpfs_lookup() and thus tmpfs_vnode_get() to associate a new vnode. 70 * 71 * Lock order 72 * 73 * tmpfs_node_t::tn_nlock -> 74 * struct vnode::v_vlock -> 75 * struct vnode::v_interlock 76 */ 77 78 #include <sys/param.h> 79 #include <sys/dirent.h> 80 #include <sys/event.h> 81 #include <sys/mount.h> 82 #include <sys/namei.h> 83 #include <sys/time.h> 84 #include <sys/proc.h> 85 #include <sys/stat.h> 86 #include <sys/systm.h> 87 #include <sys/vnode.h> 88 89 #include <uvm/uvm_aobj.h> 90 91 #include <tmpfs/tmpfs.h> 92 #include <tmpfs/tmpfs_vnops.h> 93 94 95 /* Local functions. */ 96 void tmpfs_dir_putseq(tmpfs_node_t *, tmpfs_dirent_t *); 97 int tmpfs_dir_getdotents(tmpfs_node_t *, struct dirent *, struct uio *); 98 99 /* 100 * tmpfs_alloc_node: allocate a new inode of a specified type and 101 * insert it into the list of specified mount point. 102 */ 103 int 104 tmpfs_alloc_node(tmpfs_mount_t *tmp, enum vtype type, uid_t uid, gid_t gid, 105 mode_t mode, char *target, dev_t rdev, tmpfs_node_t **node) 106 { 107 tmpfs_node_t *nnode; 108 struct uvm_object *uobj; 109 110 nnode = tmpfs_node_get(tmp); 111 if (nnode == NULL) { 112 return ENOSPC; 113 } 114 115 /* Initially, no references and no associations. */ 116 nnode->tn_links = 0; 117 nnode->tn_vnode = NULL; 118 nnode->tn_dirent_hint = NULL; 119 120 rw_enter_write(&tmp->tm_acc_lock); 121 nnode->tn_id = ++tmp->tm_highest_inode; 122 if (nnode->tn_id == 0) { 123 --tmp->tm_highest_inode; 124 rw_exit_write(&tmp->tm_acc_lock); 125 tmpfs_node_put(tmp, nnode); 126 return ENOSPC; 127 } 128 rw_exit_write(&tmp->tm_acc_lock); 129 130 /* Generic initialization. */ 131 nnode->tn_type = type; 132 nnode->tn_size = 0; 133 nnode->tn_flags = 0; 134 nnode->tn_lockf = NULL; 135 nnode->tn_gen = TMPFS_NODE_GEN_MASK & arc4random(); 136 137 nanotime(&nnode->tn_atime); 138 nnode->tn_birthtime = nnode->tn_atime; 139 nnode->tn_ctime = nnode->tn_atime; 140 nnode->tn_mtime = nnode->tn_atime; 141 142 KASSERT(uid != VNOVAL && gid != VNOVAL && mode != VNOVAL); 143 144 nnode->tn_uid = uid; 145 nnode->tn_gid = gid; 146 nnode->tn_mode = mode; 147 148 /* Type-specific initialization. */ 149 switch (nnode->tn_type) { 150 case VBLK: 151 case VCHR: 152 /* Character/block special device. */ 153 KASSERT(rdev != VNOVAL); 154 nnode->tn_spec.tn_dev.tn_rdev = rdev; 155 break; 156 case VDIR: 157 /* Directory. */ 158 TAILQ_INIT(&nnode->tn_spec.tn_dir.tn_dir); 159 nnode->tn_spec.tn_dir.tn_parent = NULL; 160 nnode->tn_spec.tn_dir.tn_next_seq = TMPFS_DIRSEQ_START; 161 nnode->tn_spec.tn_dir.tn_readdir_lastp = NULL; 162 163 /* Extra link count for the virtual '.' entry. */ 164 nnode->tn_links++; 165 break; 166 case VFIFO: 167 case VSOCK: 168 break; 169 case VLNK: 170 /* Symbolic link. Target specifies the file name. */ 171 KASSERT(target && strlen(target) < MAXPATHLEN); 172 173 nnode->tn_size = strlen(target); 174 if (nnode->tn_size == 0) { 175 nnode->tn_spec.tn_lnk.tn_link = NULL; 176 break; 177 } 178 nnode->tn_spec.tn_lnk.tn_link = 179 tmpfs_strname_alloc(tmp, nnode->tn_size); 180 if (nnode->tn_spec.tn_lnk.tn_link == NULL) { 181 tmpfs_node_put(tmp, nnode); 182 return ENOSPC; 183 } 184 memcpy(nnode->tn_spec.tn_lnk.tn_link, target, nnode->tn_size); 185 break; 186 case VREG: 187 /* Regular file. Create an underlying UVM object. */ 188 uobj = uao_create(0, UAO_FLAG_CANFAIL); 189 if (uobj == NULL) { 190 tmpfs_node_put(tmp, nnode); 191 return ENOSPC; 192 } 193 nnode->tn_spec.tn_reg.tn_aobj = uobj; 194 nnode->tn_spec.tn_reg.tn_aobj_pages = 0; 195 nnode->tn_spec.tn_reg.tn_aobj_pgptr = (vaddr_t)NULL; 196 nnode->tn_spec.tn_reg.tn_aobj_pgnum = (voff_t)-1; 197 break; 198 default: 199 KASSERT(0); 200 } 201 202 rw_init(&nnode->tn_nlock, "tvlk"); 203 204 rw_enter_write(&tmp->tm_lock); 205 LIST_INSERT_HEAD(&tmp->tm_nodes, nnode, tn_entries); 206 rw_exit_write(&tmp->tm_lock); 207 208 *node = nnode; 209 return 0; 210 } 211 212 /* 213 * tmpfs_free_node: remove the inode from a list in the mount point and 214 * destroy the inode structures. 215 */ 216 void 217 tmpfs_free_node(tmpfs_mount_t *tmp, tmpfs_node_t *node) 218 { 219 size_t objsz; 220 221 rw_enter_write(&tmp->tm_lock); 222 LIST_REMOVE(node, tn_entries); 223 rw_exit_write(&tmp->tm_lock); 224 225 switch (node->tn_type) { 226 case VLNK: 227 if (node->tn_size > 0) { 228 KASSERT(node->tn_size <= SIZE_MAX); 229 tmpfs_strname_free(tmp, node->tn_spec.tn_lnk.tn_link, 230 node->tn_size); 231 } 232 break; 233 case VREG: 234 /* 235 * Calculate the size of inode data, decrease the used-memory 236 * counter, and destroy the underlying UVM object (if any). 237 */ 238 objsz = PAGE_SIZE * node->tn_spec.tn_reg.tn_aobj_pages; 239 if (objsz != 0) { 240 tmpfs_mem_decr(tmp, objsz); 241 } 242 if (node->tn_spec.tn_reg.tn_aobj != NULL) { 243 uao_detach(node->tn_spec.tn_reg.tn_aobj); 244 node->tn_spec.tn_reg.tn_aobj = NULL; 245 } 246 break; 247 case VDIR: 248 KASSERT(TAILQ_EMPTY(&node->tn_spec.tn_dir.tn_dir)); 249 KASSERT(node->tn_spec.tn_dir.tn_parent == NULL || 250 node == tmp->tm_root); 251 break; 252 default: 253 break; 254 } 255 256 rw_enter_write(&tmp->tm_acc_lock); 257 if (node->tn_id == tmp->tm_highest_inode) 258 --tmp->tm_highest_inode; 259 rw_exit_write(&tmp->tm_acc_lock); 260 261 /* mutex_destroy(&node->tn_nlock); */ 262 tmpfs_node_put(tmp, node); 263 } 264 265 /* 266 * tmpfs_vnode_get: allocate or reclaim a vnode for a specified inode. 267 * 268 * => Must be called with tmpfs_node_t::tn_nlock held. 269 * => Returns vnode (*vpp) locked. 270 */ 271 int 272 tmpfs_vnode_get(struct mount *mp, tmpfs_node_t *node, struct vnode **vpp) 273 { 274 struct vnode *vp, *nvp; 275 /* kmutex_t *slock; */ 276 int error; 277 again: 278 /* If there is already a vnode, try to reclaim it. */ 279 if ((vp = node->tn_vnode) != NULL) { 280 /* atomic_or_ulong(&node->tn_gen, TMPFS_RECLAIMING_BIT); */ 281 node->tn_gen |= TMPFS_RECLAIMING_BIT; 282 rw_exit_write(&node->tn_nlock); 283 error = vget(vp, LK_EXCLUSIVE); 284 if (error == ENOENT) { 285 rw_enter_write(&node->tn_nlock); 286 goto again; 287 } 288 /* atomic_and_ulong(&node->tn_gen, ~TMPFS_RECLAIMING_BIT); */ 289 node->tn_gen &= ~TMPFS_RECLAIMING_BIT; 290 *vpp = vp; 291 return error; 292 } 293 if (TMPFS_NODE_RECLAIMING(node)) { 294 /* atomic_and_ulong(&node->tn_gen, ~TMPFS_RECLAIMING_BIT); */ 295 node->tn_gen &= ~TMPFS_RECLAIMING_BIT; 296 } 297 298 /* 299 * Get a new vnode and associate it with our inode. Share the 300 * lock with underlying UVM object, if there is one (VREG case). 301 */ 302 #if 0 303 if (node->tn_type == VREG) { 304 struct uvm_object *uobj = node->tn_spec.tn_reg.tn_aobj; 305 slock = uobj->vmobjlock; 306 } else { 307 slock = NULL; 308 } 309 #endif 310 error = getnewvnode(VT_TMPFS, mp, &tmpfs_vops, &vp); 311 if (error) { 312 rw_exit_write(&node->tn_nlock); 313 return error; 314 } 315 316 rrw_init_flags(&node->tn_vlock, "tnode", RWL_DUPOK | RWL_IS_VNODE); 317 vp->v_type = node->tn_type; 318 319 /* Type-specific initialization. */ 320 switch (node->tn_type) { 321 case VBLK: 322 case VCHR: 323 vp->v_op = &tmpfs_specvops; 324 if ((nvp = checkalias(vp, node->tn_spec.tn_dev.tn_rdev, mp))) { 325 nvp->v_data = vp->v_data; 326 vp->v_data = NULL; 327 vp->v_op = &spec_vops; 328 vrele(vp); 329 vgone(vp); 330 vp = nvp; 331 node->tn_vnode = vp; 332 } 333 break; 334 case VDIR: 335 vp->v_flag |= node->tn_spec.tn_dir.tn_parent == node ? 336 VROOT : 0; 337 break; 338 #ifdef FIFO 339 case VFIFO: 340 vp->v_op = &tmpfs_fifovops; 341 break; 342 #endif 343 case VLNK: 344 case VREG: 345 case VSOCK: 346 break; 347 default: 348 KASSERT(0); 349 } 350 351 uvm_vnp_setsize(vp, node->tn_size); 352 vp->v_data = node; 353 node->tn_vnode = vp; 354 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 355 rw_exit_write(&node->tn_nlock); 356 357 KASSERT(VOP_ISLOCKED(vp)); 358 *vpp = vp; 359 return 0; 360 } 361 362 /* 363 * tmpfs_alloc_file: allocate a new file of specified type and adds it 364 * into the parent directory. 365 * 366 * => Credentials of the caller are used. 367 */ 368 int 369 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 370 struct componentname *cnp, char *target) 371 { 372 tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount); 373 tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp), *node; 374 tmpfs_dirent_t *de; 375 int error; 376 377 KASSERT(VOP_ISLOCKED(dvp)); 378 *vpp = NULL; 379 380 /* Check for the maximum number of links limit. */ 381 if (vap->va_type == VDIR) { 382 /* Check for maximum links limit. */ 383 if (dnode->tn_links == LINK_MAX) { 384 error = EMLINK; 385 goto out; 386 } 387 KASSERT(dnode->tn_links < LINK_MAX); 388 } 389 390 if (TMPFS_DIRSEQ_FULL(dnode)) { 391 error = ENOSPC; 392 goto out; 393 } 394 395 if (dnode->tn_links == 0) { 396 error = ENOENT; 397 goto out; 398 } 399 400 /* Allocate a node that represents the new file. */ 401 error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid, 402 dnode->tn_gid, vap->va_mode, target, vap->va_rdev, &node); 403 if (error) 404 goto out; 405 406 /* Allocate a directory entry that points to the new file. */ 407 error = tmpfs_alloc_dirent(tmp, cnp->cn_nameptr, cnp->cn_namelen, &de); 408 if (error) { 409 tmpfs_free_node(tmp, node); 410 goto out; 411 } 412 413 /* Get a vnode for the new file. */ 414 rw_enter_write(&node->tn_nlock); 415 error = tmpfs_vnode_get(dvp->v_mount, node, vpp); 416 if (error) { 417 tmpfs_free_dirent(tmp, de); 418 tmpfs_free_node(tmp, node); 419 goto out; 420 } 421 422 /* Associate inode and attach the entry into the directory. */ 423 tmpfs_dir_attach(dnode, de, node); 424 425 out: 426 if (error == 0 && (cnp->cn_flags & SAVESTART) == 0) 427 pool_put(&namei_pool, cnp->cn_pnbuf); 428 return error; 429 } 430 431 /* 432 * tmpfs_alloc_dirent: allocates a new directory entry for the inode. 433 * The directory entry contains a path name component. 434 */ 435 int 436 tmpfs_alloc_dirent(tmpfs_mount_t *tmp, const char *name, uint16_t len, 437 tmpfs_dirent_t **de) 438 { 439 tmpfs_dirent_t *nde; 440 441 nde = tmpfs_dirent_get(tmp); 442 if (nde == NULL) 443 return ENOSPC; 444 445 nde->td_name = tmpfs_strname_alloc(tmp, len); 446 if (nde->td_name == NULL) { 447 tmpfs_dirent_put(tmp, nde); 448 return ENOSPC; 449 } 450 nde->td_namelen = len; 451 memcpy(nde->td_name, name, len); 452 nde->td_seq = TMPFS_DIRSEQ_NONE; 453 454 *de = nde; 455 return 0; 456 } 457 458 /* 459 * tmpfs_free_dirent: free a directory entry. 460 */ 461 void 462 tmpfs_free_dirent(tmpfs_mount_t *tmp, tmpfs_dirent_t *de) 463 { 464 KASSERT(de->td_node == NULL); 465 KASSERT(de->td_seq == TMPFS_DIRSEQ_NONE); 466 tmpfs_strname_free(tmp, de->td_name, de->td_namelen); 467 tmpfs_dirent_put(tmp, de); 468 } 469 470 /* 471 * tmpfs_dir_attach: associate directory entry with a specified inode, 472 * and attach the entry into the directory, specified by vnode. 473 * 474 * => Increases link count on the associated node. 475 * => Increases link count on directory node, if our node is VDIR. 476 * It is caller's responsibility to check for the LINK_MAX limit. 477 * => Triggers kqueue events here. 478 */ 479 void 480 tmpfs_dir_attach(tmpfs_node_t *dnode, tmpfs_dirent_t *de, tmpfs_node_t *node) 481 { 482 struct vnode *dvp = dnode->tn_vnode; 483 int events = NOTE_WRITE; 484 485 KASSERT(dvp != NULL); 486 KASSERT(VOP_ISLOCKED(dvp)); 487 488 /* Get a new sequence number. */ 489 KASSERT(de->td_seq == TMPFS_DIRSEQ_NONE); 490 de->td_seq = tmpfs_dir_getseq(dnode, de); 491 492 /* Associate directory entry and the inode. */ 493 de->td_node = node; 494 KASSERT(node->tn_links < LINK_MAX); 495 node->tn_links++; 496 497 /* Save the hint (might overwrite). */ 498 node->tn_dirent_hint = de; 499 500 /* Insert the entry to the directory (parent of inode). */ 501 TAILQ_INSERT_TAIL(&dnode->tn_spec.tn_dir.tn_dir, de, td_entries); 502 dnode->tn_size += sizeof(tmpfs_dirent_t); 503 tmpfs_update(dnode, TMPFS_NODE_STATUSALL); 504 uvm_vnp_setsize(dvp, dnode->tn_size); 505 506 if (node->tn_type == VDIR) { 507 /* Set parent. */ 508 KASSERT(node->tn_spec.tn_dir.tn_parent == NULL); 509 node->tn_spec.tn_dir.tn_parent = dnode; 510 511 /* Increase the link count of parent. */ 512 KASSERT(dnode->tn_links < LINK_MAX); 513 dnode->tn_links++; 514 events |= NOTE_LINK; 515 516 TMPFS_VALIDATE_DIR(node); 517 } 518 VN_KNOTE(dvp, events); 519 } 520 521 /* 522 * tmpfs_dir_detach: disassociate directory entry and its inode, 523 * and detach the entry from the directory, specified by vnode. 524 * 525 * => Decreases link count on the associated node. 526 * => Decreases the link count on directory node, if our node is VDIR. 527 * => Triggers kqueue events here. 528 */ 529 void 530 tmpfs_dir_detach(tmpfs_node_t *dnode, tmpfs_dirent_t *de) 531 { 532 tmpfs_node_t *node = de->td_node; 533 struct vnode *vp, *dvp = dnode->tn_vnode; 534 int events = NOTE_WRITE; 535 536 KASSERT(dvp == NULL || VOP_ISLOCKED(dvp)); 537 538 /* Deassociate the inode and entry. */ 539 de->td_node = NULL; 540 node->tn_dirent_hint = NULL; 541 542 KASSERT(node->tn_links > 0); 543 node->tn_links--; 544 if ((vp = node->tn_vnode) != NULL) { 545 KASSERT(VOP_ISLOCKED(vp)); 546 VN_KNOTE(vp, node->tn_links ? NOTE_LINK : NOTE_DELETE); 547 } 548 549 /* If directory - decrease the link count of parent. */ 550 if (node->tn_type == VDIR) { 551 KASSERT(node->tn_spec.tn_dir.tn_parent == dnode); 552 node->tn_spec.tn_dir.tn_parent = NULL; 553 554 KASSERT(dnode->tn_links > 0); 555 dnode->tn_links--; 556 events |= NOTE_LINK; 557 } 558 559 /* Remove the entry from the directory. */ 560 if (dnode->tn_spec.tn_dir.tn_readdir_lastp == de) { 561 dnode->tn_spec.tn_dir.tn_readdir_lastp = NULL; 562 } 563 TAILQ_REMOVE(&dnode->tn_spec.tn_dir.tn_dir, de, td_entries); 564 565 dnode->tn_size -= sizeof(tmpfs_dirent_t); 566 tmpfs_update(dnode, TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); 567 tmpfs_dir_putseq(dnode, de); 568 if (dvp) { 569 tmpfs_update(dnode, 0); 570 uvm_vnp_setsize(dvp, dnode->tn_size); 571 VN_KNOTE(dvp, events); 572 } 573 } 574 575 /* 576 * tmpfs_dir_lookup: find a directory entry in the specified inode. 577 * 578 * Note that the . and .. components are not allowed as they do not 579 * physically exist within directories. 580 */ 581 tmpfs_dirent_t * 582 tmpfs_dir_lookup(tmpfs_node_t *node, struct componentname *cnp) 583 { 584 const char *name = cnp->cn_nameptr; 585 const uint16_t nlen = cnp->cn_namelen; 586 tmpfs_dirent_t *de; 587 588 KASSERT(VOP_ISLOCKED(node->tn_vnode)); 589 KASSERT(nlen != 1 || !(name[0] == '.')); 590 KASSERT(nlen != 2 || !(name[0] == '.' && name[1] == '.')); 591 TMPFS_VALIDATE_DIR(node); 592 593 TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) { 594 if (de->td_namelen != nlen) 595 continue; 596 if (memcmp(de->td_name, name, nlen) != 0) 597 continue; 598 break; 599 } 600 tmpfs_update(node, TMPFS_NODE_ACCESSED); 601 return de; 602 } 603 604 /* 605 * tmpfs_dir_cached: get a cached directory entry if it is valid. Used to 606 * avoid unnecessary tmpfs_dir_lookup(). 607 * 608 * => The vnode must be locked. 609 */ 610 tmpfs_dirent_t * 611 tmpfs_dir_cached(tmpfs_node_t *node) 612 { 613 tmpfs_dirent_t *de = node->tn_dirent_hint; 614 615 KASSERT(VOP_ISLOCKED(node->tn_vnode)); 616 617 if (de == NULL) { 618 return NULL; 619 } 620 KASSERT(de->td_node == node); 621 622 /* 623 * Directories always have a valid hint. For files, check if there 624 * are any hard links. If there are - hint might be invalid. 625 */ 626 return (node->tn_type != VDIR && node->tn_links > 1) ? NULL : de; 627 } 628 629 /* 630 * tmpfs_dir_getseq: get a per-directory sequence number for the entry. 631 */ 632 uint64_t 633 tmpfs_dir_getseq(tmpfs_node_t *dnode, tmpfs_dirent_t *de) 634 { 635 uint64_t seq = de->td_seq; 636 637 TMPFS_VALIDATE_DIR(dnode); 638 639 if (__predict_true(seq != TMPFS_DIRSEQ_NONE)) { 640 /* Already set. */ 641 KASSERT(seq >= TMPFS_DIRSEQ_START); 642 return seq; 643 } 644 645 /* 646 * The "." and ".." and the end-of-directory have reserved numbers. 647 * The other sequence numbers are allocated incrementally. 648 */ 649 650 seq = dnode->tn_spec.tn_dir.tn_next_seq; 651 KASSERT(seq >= TMPFS_DIRSEQ_START); 652 KASSERT(seq < TMPFS_DIRSEQ_END); 653 dnode->tn_spec.tn_dir.tn_next_seq++; 654 return seq; 655 } 656 657 void 658 tmpfs_dir_putseq(tmpfs_node_t *dnode, tmpfs_dirent_t *de) 659 { 660 uint64_t seq = de->td_seq; 661 662 TMPFS_VALIDATE_DIR(dnode); 663 KASSERT(seq == TMPFS_DIRSEQ_NONE || seq >= TMPFS_DIRSEQ_START); 664 KASSERT(seq == TMPFS_DIRSEQ_NONE || seq < TMPFS_DIRSEQ_END); 665 666 de->td_seq = TMPFS_DIRSEQ_NONE; 667 668 /* Empty? We can reset. */ 669 if (dnode->tn_size == 0) { 670 dnode->tn_spec.tn_dir.tn_next_seq = TMPFS_DIRSEQ_START; 671 } else if (seq != TMPFS_DIRSEQ_NONE && 672 seq == dnode->tn_spec.tn_dir.tn_next_seq - 1) { 673 dnode->tn_spec.tn_dir.tn_next_seq--; 674 } 675 } 676 677 /* 678 * tmpfs_dir_lookupbyseq: lookup a directory entry by the sequence number. 679 */ 680 tmpfs_dirent_t * 681 tmpfs_dir_lookupbyseq(tmpfs_node_t *node, off_t seq) 682 { 683 tmpfs_dirent_t *de = node->tn_spec.tn_dir.tn_readdir_lastp; 684 685 TMPFS_VALIDATE_DIR(node); 686 687 /* 688 * First, check the cache. If does not match - perform a lookup. 689 */ 690 if (de && de->td_seq == seq) { 691 KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); 692 KASSERT(de->td_seq != TMPFS_DIRSEQ_NONE); 693 return de; 694 } 695 TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) { 696 KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); 697 KASSERT(de->td_seq != TMPFS_DIRSEQ_NONE); 698 if (de->td_seq == seq) 699 return de; 700 } 701 return NULL; 702 } 703 704 /* 705 * tmpfs_dir_getdotents: helper function for tmpfs_readdir() to get the 706 * dot meta entries, that is, "." or "..". Copy it to the UIO space. 707 */ 708 int 709 tmpfs_dir_getdotents(tmpfs_node_t *node, struct dirent *dp, struct uio *uio) 710 { 711 tmpfs_dirent_t *de; 712 off_t next = 0; 713 int error; 714 715 switch (uio->uio_offset) { 716 case TMPFS_DIRSEQ_DOT: 717 dp->d_fileno = node->tn_id; 718 strlcpy(dp->d_name, ".", sizeof(dp->d_name)); 719 next = TMPFS_DIRSEQ_DOTDOT; 720 break; 721 case TMPFS_DIRSEQ_DOTDOT: 722 dp->d_fileno = node->tn_spec.tn_dir.tn_parent->tn_id; 723 strlcpy(dp->d_name, "..", sizeof(dp->d_name)); 724 de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir); 725 next = de ? tmpfs_dir_getseq(node, de) : TMPFS_DIRSEQ_EOF; 726 break; 727 default: 728 KASSERT(false); 729 } 730 dp->d_type = DT_DIR; 731 dp->d_namlen = strlen(dp->d_name); 732 dp->d_reclen = DIRENT_SIZE(dp); 733 dp->d_off = next; 734 735 if (dp->d_reclen > uio->uio_resid) { 736 return EJUSTRETURN; 737 } 738 739 if ((error = uiomove(dp, dp->d_reclen, uio)) != 0) { 740 return error; 741 } 742 743 uio->uio_offset = next; 744 return error; 745 } 746 747 /* 748 * tmpfs_dir_getdents: helper function for tmpfs_readdir. 749 * 750 * => Returns as much directory entries as can fit in the uio space. 751 * => The read starts at uio->uio_offset. 752 */ 753 int 754 tmpfs_dir_getdents(tmpfs_node_t *node, struct uio *uio) 755 { 756 tmpfs_dirent_t *de, *next_de; 757 struct dirent dent; 758 int error = 0; 759 760 KASSERT(VOP_ISLOCKED(node->tn_vnode)); 761 TMPFS_VALIDATE_DIR(node); 762 memset(&dent, 0, sizeof(dent)); 763 764 if (uio->uio_offset == TMPFS_DIRSEQ_DOT) { 765 if ((error = tmpfs_dir_getdotents(node, &dent, uio)) != 0) { 766 goto done; 767 } 768 } 769 if (uio->uio_offset == TMPFS_DIRSEQ_DOTDOT) { 770 if ((error = tmpfs_dir_getdotents(node, &dent, uio)) != 0) { 771 goto done; 772 } 773 } 774 /* Done if we reached the end. */ 775 if (uio->uio_offset == TMPFS_DIRSEQ_EOF) { 776 goto done; 777 } 778 779 /* Locate the directory entry given by the given sequence number. */ 780 de = tmpfs_dir_lookupbyseq(node, uio->uio_offset); 781 if (de == NULL) { 782 error = EINVAL; 783 goto done; 784 } 785 786 /* 787 * Read as many entries as possible; i.e., until we reach the end 788 * of the directory or we exhaust UIO space. 789 */ 790 do { 791 dent.d_fileno = de->td_node->tn_id; 792 switch (de->td_node->tn_type) { 793 case VBLK: 794 dent.d_type = DT_BLK; 795 break; 796 case VCHR: 797 dent.d_type = DT_CHR; 798 break; 799 case VDIR: 800 dent.d_type = DT_DIR; 801 break; 802 case VFIFO: 803 dent.d_type = DT_FIFO; 804 break; 805 case VLNK: 806 dent.d_type = DT_LNK; 807 break; 808 case VREG: 809 dent.d_type = DT_REG; 810 break; 811 case VSOCK: 812 dent.d_type = DT_SOCK; 813 break; 814 default: 815 KASSERT(0); 816 } 817 dent.d_namlen = de->td_namelen; 818 KASSERT(de->td_namelen < sizeof(dent.d_name)); 819 memcpy(dent.d_name, de->td_name, de->td_namelen); 820 dent.d_name[de->td_namelen] = '\0'; 821 dent.d_reclen = DIRENT_SIZE(&dent); 822 823 next_de = TAILQ_NEXT(de, td_entries); 824 if (next_de == NULL) 825 dent.d_off = TMPFS_DIRSEQ_EOF; 826 else 827 dent.d_off = tmpfs_dir_getseq(node, next_de); 828 829 if (dent.d_reclen > uio->uio_resid) { 830 /* Exhausted UIO space. */ 831 error = EJUSTRETURN; 832 break; 833 } 834 835 /* Copy out the directory entry and continue. */ 836 error = uiomove(&dent, dent.d_reclen, uio); 837 if (error) { 838 break; 839 } 840 de = TAILQ_NEXT(de, td_entries); 841 842 } while (uio->uio_resid > 0 && de); 843 844 /* Cache the last entry or clear and mark EOF. */ 845 uio->uio_offset = de ? tmpfs_dir_getseq(node, de) : TMPFS_DIRSEQ_EOF; 846 node->tn_spec.tn_dir.tn_readdir_lastp = de; 847 done: 848 tmpfs_update(node, TMPFS_NODE_ACCESSED); 849 850 if (error == EJUSTRETURN) { 851 /* Exhausted UIO space - just return. */ 852 error = 0; 853 } 854 KASSERT(error >= 0); 855 return error; 856 } 857 858 /* 859 * tmpfs_reg_resize: resize the underlying UVM object associated with the 860 * specified regular file. 861 */ 862 863 int 864 tmpfs_reg_resize(struct vnode *vp, off_t newsize) 865 { 866 tmpfs_mount_t *tmp = VFS_TO_TMPFS(vp->v_mount); 867 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 868 struct uvm_object *uobj = node->tn_spec.tn_reg.tn_aobj; 869 size_t newpages, oldpages, bytes; 870 off_t oldsize; 871 vaddr_t pgoff; 872 int error; 873 874 KASSERT(vp->v_type == VREG); 875 KASSERT(newsize >= 0); 876 877 oldsize = node->tn_size; 878 oldpages = round_page(oldsize) >> PAGE_SHIFT; 879 newpages = round_page(newsize) >> PAGE_SHIFT; 880 KASSERT(oldpages == node->tn_spec.tn_reg.tn_aobj_pages); 881 882 if (newpages > oldpages) { 883 /* Increase the used-memory counter if getting extra pages. */ 884 bytes = (newpages - oldpages) << PAGE_SHIFT; 885 if (tmpfs_mem_incr(tmp, bytes) == 0) 886 return ENOSPC; 887 rw_enter(uobj->vmobjlock, RW_WRITE); 888 error = uao_grow(uobj, newpages); 889 rw_exit(uobj->vmobjlock); 890 if (error) { 891 tmpfs_mem_decr(tmp, bytes); 892 return ENOSPC; 893 } 894 } 895 896 node->tn_spec.tn_reg.tn_aobj_pages = newpages; 897 node->tn_size = newsize; 898 uvm_vnp_setsize(vp, newsize); 899 uvm_vnp_uncache(vp); 900 901 /* 902 * Free "backing store". 903 */ 904 if (newpages < oldpages) { 905 if (tmpfs_uio_cached(node)) 906 tmpfs_uio_uncache(node); 907 rw_enter(uobj->vmobjlock, RW_WRITE); 908 if (uao_shrink(uobj, newpages)) 909 panic("shrink failed"); 910 rw_exit(uobj->vmobjlock); 911 /* Decrease the used-memory counter. */ 912 tmpfs_mem_decr(tmp, (oldpages - newpages) << PAGE_SHIFT); 913 } 914 if (newsize > oldsize) { 915 if (tmpfs_uio_cached(node)) 916 tmpfs_uio_uncache(node); 917 pgoff = oldsize & PAGE_MASK; 918 if (pgoff != 0) { 919 /* 920 * Growing from an offset which is not at a page 921 * boundary; zero out unused bytes in current page. 922 */ 923 error = tmpfs_zeropg(node, trunc_page(oldsize), pgoff); 924 if (error) 925 panic("tmpfs_zeropg: error %d", error); 926 } 927 VN_KNOTE(vp, NOTE_EXTEND); 928 } 929 return 0; 930 } 931 932 /* 933 * tmpfs_chflags: change flags of the given vnode. 934 * 935 */ 936 int 937 tmpfs_chflags(struct vnode *vp, int flags, struct ucred *cred, struct proc *p) 938 { 939 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 940 int error; 941 942 KASSERT(VOP_ISLOCKED(vp)); 943 944 /* Disallow this operation if the file system is mounted read-only. */ 945 if (vp->v_mount->mnt_flag & MNT_RDONLY) 946 return EROFS; 947 948 if (cred->cr_uid != node->tn_uid && (error = suser_ucred(cred))) 949 return error; 950 951 if (cred->cr_uid == 0) { 952 if (node->tn_flags & (SF_IMMUTABLE | SF_APPEND) && 953 securelevel > 0) 954 return EPERM; 955 node->tn_flags = flags; 956 } else { 957 if (node->tn_flags & (SF_IMMUTABLE | SF_APPEND) || 958 (flags & UF_SETTABLE) != flags) 959 return EPERM; 960 node->tn_flags &= SF_SETTABLE; 961 node->tn_flags |= (flags & UF_SETTABLE); 962 } 963 964 tmpfs_update(node, TMPFS_NODE_CHANGED); 965 VN_KNOTE(vp, NOTE_ATTRIB); 966 return 0; 967 } 968 969 /* 970 * tmpfs_chmod: change access mode on the given vnode. 971 * 972 */ 973 int 974 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct proc *p) 975 { 976 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 977 int error; 978 979 KASSERT(VOP_ISLOCKED(vp)); 980 981 /* Disallow this operation if the file system is mounted read-only. */ 982 if (vp->v_mount->mnt_flag & MNT_RDONLY) 983 return EROFS; 984 985 /* Immutable or append-only files cannot be modified, either. */ 986 if (node->tn_flags & (IMMUTABLE | APPEND)) 987 return EPERM; 988 989 if (cred->cr_uid != node->tn_uid && (error = suser_ucred(cred))) 990 return error; 991 if (cred->cr_uid != 0) { 992 if (vp->v_type != VDIR && (mode & S_ISTXT)) 993 return EFTYPE; 994 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) 995 return EPERM; 996 } 997 998 node->tn_mode = (mode & ALLPERMS); 999 tmpfs_update(node, TMPFS_NODE_CHANGED); 1000 if ((vp->v_flag & VTEXT) && (node->tn_mode & S_ISTXT) == 0) 1001 uvm_vnp_uncache(vp); 1002 VN_KNOTE(vp, NOTE_ATTRIB); 1003 return 0; 1004 } 1005 1006 /* 1007 * tmpfs_chown: change ownership of the given vnode. 1008 * 1009 * => At least one of uid or gid must be different than VNOVAL. 1010 * => Attribute is unchanged for VNOVAL case. 1011 */ 1012 int 1013 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, struct proc *p) 1014 { 1015 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1016 int error; 1017 1018 KASSERT(VOP_ISLOCKED(vp)); 1019 1020 /* Assign default values if they are unknown. */ 1021 KASSERT(uid != VNOVAL || gid != VNOVAL); 1022 if (uid == VNOVAL) { 1023 uid = node->tn_uid; 1024 } 1025 if (gid == VNOVAL) { 1026 gid = node->tn_gid; 1027 } 1028 1029 /* Disallow this operation if the file system is mounted read-only. */ 1030 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1031 return EROFS; 1032 1033 /* Immutable or append-only files cannot be modified, either. */ 1034 if (node->tn_flags & (IMMUTABLE | APPEND)) 1035 return EPERM; 1036 1037 if ((cred->cr_uid != node->tn_uid || uid != node->tn_uid || 1038 (gid != node->tn_gid && !groupmember(gid, cred))) && 1039 (error = suser_ucred(cred))) 1040 return error; 1041 1042 node->tn_uid = uid; 1043 node->tn_gid = gid; 1044 tmpfs_update(node, TMPFS_NODE_CHANGED); 1045 VN_KNOTE(vp, NOTE_ATTRIB); 1046 return 0; 1047 } 1048 1049 /* 1050 * tmpfs_chsize: change size of the given vnode. 1051 */ 1052 int 1053 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, struct proc *p) 1054 { 1055 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1056 1057 KASSERT(VOP_ISLOCKED(vp)); 1058 1059 /* Decide whether this is a valid operation based on the file type. */ 1060 switch (vp->v_type) { 1061 case VDIR: 1062 return EISDIR; 1063 case VREG: 1064 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 1065 return EROFS; 1066 } 1067 break; 1068 case VBLK: 1069 case VCHR: 1070 case VFIFO: 1071 /* 1072 * Allow modifications of special files even if in the file 1073 * system is mounted read-only (we are not modifying the 1074 * files themselves, but the objects they represent). 1075 */ 1076 return 0; 1077 default: 1078 return EOPNOTSUPP; 1079 } 1080 1081 /* Immutable or append-only files cannot be modified, either. */ 1082 if (node->tn_flags & (IMMUTABLE | APPEND)) { 1083 return EPERM; 1084 } 1085 1086 /* Note: tmpfs_truncate() will raise NOTE_EXTEND and NOTE_ATTRIB. */ 1087 return tmpfs_truncate(vp, size); 1088 } 1089 1090 /* 1091 * tmpfs_chtimes: change access and modification times for vnode. 1092 */ 1093 int 1094 tmpfs_chtimes(struct vnode *vp, const struct timespec *atime, 1095 const struct timespec *mtime, int vaflags, struct ucred *cred, 1096 struct proc *p) 1097 { 1098 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1099 int error; 1100 1101 KASSERT(VOP_ISLOCKED(vp)); 1102 1103 /* Disallow this operation if the file system is mounted read-only. */ 1104 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1105 return EROFS; 1106 1107 /* Immutable or append-only files cannot be modified, either. */ 1108 if (node->tn_flags & (IMMUTABLE | APPEND)) 1109 return EPERM; 1110 1111 if (cred->cr_uid != node->tn_uid && (error = suser_ucred(cred)) && 1112 ((vaflags & VA_UTIMES_NULL) == 0 || 1113 (error = VOP_ACCESS(vp, VWRITE, cred, p)))) 1114 return error; 1115 1116 if (atime->tv_nsec != VNOVAL) 1117 node->tn_atime = *atime; 1118 1119 if (mtime->tv_nsec != VNOVAL) 1120 node->tn_mtime = *mtime; 1121 1122 if (mtime->tv_nsec != VNOVAL || (vaflags & VA_UTIMES_CHANGE)) 1123 tmpfs_update(VP_TO_TMPFS_NODE(vp), TMPFS_NODE_CHANGED); 1124 1125 VN_KNOTE(vp, NOTE_ATTRIB); 1126 1127 return 0; 1128 } 1129 1130 /* 1131 * tmpfs_update: update timestamps, et al. 1132 */ 1133 void 1134 tmpfs_update(tmpfs_node_t *node, int flags) 1135 { 1136 struct timespec nowtm; 1137 1138 nanotime(&nowtm); 1139 1140 if (flags & TMPFS_NODE_ACCESSED) { 1141 node->tn_atime = nowtm; 1142 } 1143 if (flags & TMPFS_NODE_MODIFIED) { 1144 node->tn_mtime = nowtm; 1145 } 1146 if (flags & TMPFS_NODE_CHANGED) { 1147 node->tn_ctime = nowtm; 1148 } 1149 } 1150 1151 int 1152 tmpfs_truncate(struct vnode *vp, off_t length) 1153 { 1154 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1155 int error; 1156 1157 if (length < 0) { 1158 error = EINVAL; 1159 goto out; 1160 } 1161 if (node->tn_size == length) { 1162 error = 0; 1163 goto out; 1164 } 1165 error = tmpfs_reg_resize(vp, length); 1166 if (error == 0) { 1167 tmpfs_update(node, TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED); 1168 } 1169 out: 1170 return error; 1171 } 1172 1173 int 1174 tmpfs_uio_cached(tmpfs_node_t *node) 1175 { 1176 int pgnum_valid = (node->tn_pgnum != (voff_t)-1); 1177 int pgptr_valid = (node->tn_pgptr != (vaddr_t)NULL); 1178 KASSERT(pgnum_valid == pgptr_valid); 1179 return pgnum_valid && pgptr_valid; 1180 } 1181 1182 vaddr_t 1183 tmpfs_uio_lookup(tmpfs_node_t *node, voff_t pgnum) 1184 { 1185 if (tmpfs_uio_cached(node) == 1 && node->tn_pgnum == pgnum) 1186 return node->tn_pgptr; 1187 1188 return (vaddr_t)NULL; 1189 } 1190 1191 void 1192 tmpfs_uio_uncache(tmpfs_node_t *node) 1193 { 1194 KASSERT(node->tn_pgnum != (voff_t)-1); 1195 KASSERT(node->tn_pgptr != (vaddr_t)NULL); 1196 uvm_unmap(kernel_map, node->tn_pgptr, node->tn_pgptr + PAGE_SIZE); 1197 node->tn_pgnum = (voff_t)-1; 1198 node->tn_pgptr = (vaddr_t)NULL; 1199 } 1200 1201 void 1202 tmpfs_uio_cache(tmpfs_node_t *node, voff_t pgnum, vaddr_t pgptr) 1203 { 1204 KASSERT(node->tn_pgnum == (voff_t)-1); 1205 KASSERT(node->tn_pgptr == (vaddr_t)NULL); 1206 node->tn_pgnum = pgnum; 1207 node->tn_pgptr = pgptr; 1208 } 1209 1210 /* 1211 * Be gentle to kernel_map, don't allow more than 4MB in a single transaction. 1212 */ 1213 #define TMPFS_UIO_MAXBYTES ((1 << 22) - PAGE_SIZE) 1214 1215 int 1216 tmpfs_uiomove(tmpfs_node_t *node, struct uio *uio, vsize_t len) 1217 { 1218 vaddr_t va, pgoff; 1219 int error, adv; 1220 voff_t pgnum; 1221 vsize_t sz; 1222 1223 pgnum = trunc_page(uio->uio_offset); 1224 pgoff = uio->uio_offset & PAGE_MASK; 1225 1226 if (pgoff + len < PAGE_SIZE) { 1227 va = tmpfs_uio_lookup(node, pgnum); 1228 if (va != (vaddr_t)NULL) 1229 return uiomove((void *)va + pgoff, len, uio); 1230 } 1231 1232 if (len >= TMPFS_UIO_MAXBYTES) { 1233 sz = TMPFS_UIO_MAXBYTES; 1234 adv = MADV_NORMAL; 1235 } else { 1236 sz = len; 1237 adv = MADV_SEQUENTIAL; 1238 } 1239 1240 if (tmpfs_uio_cached(node)) 1241 tmpfs_uio_uncache(node); 1242 1243 uao_reference(node->tn_uobj); 1244 1245 error = uvm_map(kernel_map, &va, round_page(pgoff + sz), node->tn_uobj, 1246 trunc_page(uio->uio_offset), 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE, 1247 PROT_READ | PROT_WRITE, MAP_INHERIT_NONE, adv, 0)); 1248 if (error) { 1249 uao_detach(node->tn_uobj); /* Drop reference. */ 1250 return error; 1251 } 1252 1253 error = uiomove((void *)va + pgoff, sz, uio); 1254 if (error == 0 && pgoff + sz < PAGE_SIZE) 1255 tmpfs_uio_cache(node, pgnum, va); 1256 else 1257 uvm_unmap(kernel_map, va, va + round_page(pgoff + sz)); 1258 1259 return error; 1260 } 1261 1262 int 1263 tmpfs_zeropg(tmpfs_node_t *node, voff_t pgnum, vaddr_t pgoff) 1264 { 1265 vaddr_t va; 1266 int error; 1267 1268 KASSERT(tmpfs_uio_cached(node) == 0); 1269 1270 uao_reference(node->tn_uobj); 1271 1272 error = uvm_map(kernel_map, &va, PAGE_SIZE, node->tn_uobj, pgnum, 0, 1273 UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE, 1274 MAP_INHERIT_NONE, MADV_NORMAL, 0)); 1275 if (error) { 1276 uao_detach(node->tn_uobj); /* Drop reference. */ 1277 return error; 1278 } 1279 1280 bzero((void *)va + pgoff, PAGE_SIZE - pgoff); 1281 uvm_unmap(kernel_map, va, va + PAGE_SIZE); 1282 1283 return 0; 1284 } 1285