1 /* $OpenBSD: tmpfs_subr.c,v 1.23 2019/10/17 11:23:49 millert 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 { 464 465 KASSERT(de->td_node == NULL); 466 KASSERT(de->td_seq == TMPFS_DIRSEQ_NONE); 467 tmpfs_strname_free(tmp, de->td_name, de->td_namelen); 468 tmpfs_dirent_put(tmp, de); 469 } 470 471 /* 472 * tmpfs_dir_attach: associate directory entry with a specified inode, 473 * and attach the entry into the directory, specified by vnode. 474 * 475 * => Increases link count on the associated node. 476 * => Increases link count on directory node, if our node is VDIR. 477 * It is caller's responsibility to check for the LINK_MAX limit. 478 * => Triggers kqueue events here. 479 */ 480 void 481 tmpfs_dir_attach(tmpfs_node_t *dnode, tmpfs_dirent_t *de, tmpfs_node_t *node) 482 { 483 struct vnode *dvp = dnode->tn_vnode; 484 int events = NOTE_WRITE; 485 486 KASSERT(dvp != NULL); 487 KASSERT(VOP_ISLOCKED(dvp)); 488 489 /* Get a new sequence number. */ 490 KASSERT(de->td_seq == TMPFS_DIRSEQ_NONE); 491 de->td_seq = tmpfs_dir_getseq(dnode, de); 492 493 /* Associate directory entry and the inode. */ 494 de->td_node = node; 495 KASSERT(node->tn_links < LINK_MAX); 496 node->tn_links++; 497 498 /* Save the hint (might overwrite). */ 499 node->tn_dirent_hint = de; 500 501 /* Insert the entry to the directory (parent of inode). */ 502 TAILQ_INSERT_TAIL(&dnode->tn_spec.tn_dir.tn_dir, de, td_entries); 503 dnode->tn_size += sizeof(tmpfs_dirent_t); 504 tmpfs_update(dnode, TMPFS_NODE_STATUSALL); 505 uvm_vnp_setsize(dvp, dnode->tn_size); 506 507 if (node->tn_type == VDIR) { 508 /* Set parent. */ 509 KASSERT(node->tn_spec.tn_dir.tn_parent == NULL); 510 node->tn_spec.tn_dir.tn_parent = dnode; 511 512 /* Increase the link count of parent. */ 513 KASSERT(dnode->tn_links < LINK_MAX); 514 dnode->tn_links++; 515 events |= NOTE_LINK; 516 517 TMPFS_VALIDATE_DIR(node); 518 } 519 VN_KNOTE(dvp, events); 520 } 521 522 /* 523 * tmpfs_dir_detach: disassociate directory entry and its inode, 524 * and detach the entry from the directory, specified by vnode. 525 * 526 * => Decreases link count on the associated node. 527 * => Decreases the link count on directory node, if our node is VDIR. 528 * => Triggers kqueue events here. 529 */ 530 void 531 tmpfs_dir_detach(tmpfs_node_t *dnode, tmpfs_dirent_t *de) 532 { 533 tmpfs_node_t *node = de->td_node; 534 struct vnode *vp, *dvp = dnode->tn_vnode; 535 int events = NOTE_WRITE; 536 537 KASSERT(dvp == NULL || VOP_ISLOCKED(dvp)); 538 539 /* Deassociate the inode and entry. */ 540 de->td_node = NULL; 541 node->tn_dirent_hint = NULL; 542 543 KASSERT(node->tn_links > 0); 544 node->tn_links--; 545 if ((vp = node->tn_vnode) != NULL) { 546 KASSERT(VOP_ISLOCKED(vp)); 547 VN_KNOTE(vp, node->tn_links ? NOTE_LINK : NOTE_DELETE); 548 } 549 550 /* If directory - decrease the link count of parent. */ 551 if (node->tn_type == VDIR) { 552 KASSERT(node->tn_spec.tn_dir.tn_parent == dnode); 553 node->tn_spec.tn_dir.tn_parent = NULL; 554 555 KASSERT(dnode->tn_links > 0); 556 dnode->tn_links--; 557 events |= NOTE_LINK; 558 } 559 560 /* Remove the entry from the directory. */ 561 if (dnode->tn_spec.tn_dir.tn_readdir_lastp == de) { 562 dnode->tn_spec.tn_dir.tn_readdir_lastp = NULL; 563 } 564 TAILQ_REMOVE(&dnode->tn_spec.tn_dir.tn_dir, de, td_entries); 565 566 dnode->tn_size -= sizeof(tmpfs_dirent_t); 567 tmpfs_update(dnode, TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); 568 tmpfs_dir_putseq(dnode, de); 569 if (dvp) { 570 tmpfs_update(dnode, 0); 571 uvm_vnp_setsize(dvp, dnode->tn_size); 572 VN_KNOTE(dvp, events); 573 } 574 } 575 576 /* 577 * tmpfs_dir_lookup: find a directory entry in the specified inode. 578 * 579 * Note that the . and .. components are not allowed as they do not 580 * physically exist within directories. 581 */ 582 tmpfs_dirent_t * 583 tmpfs_dir_lookup(tmpfs_node_t *node, struct componentname *cnp) 584 { 585 const char *name = cnp->cn_nameptr; 586 const uint16_t nlen = cnp->cn_namelen; 587 tmpfs_dirent_t *de; 588 589 KASSERT(VOP_ISLOCKED(node->tn_vnode)); 590 KASSERT(nlen != 1 || !(name[0] == '.')); 591 KASSERT(nlen != 2 || !(name[0] == '.' && name[1] == '.')); 592 TMPFS_VALIDATE_DIR(node); 593 594 TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) { 595 if (de->td_namelen != nlen) 596 continue; 597 if (memcmp(de->td_name, name, nlen) != 0) 598 continue; 599 break; 600 } 601 tmpfs_update(node, TMPFS_NODE_ACCESSED); 602 return de; 603 } 604 605 /* 606 * tmpfs_dir_cached: get a cached directory entry if it is valid. Used to 607 * avoid unnecessary tmpfs_dir_lookup(). 608 * 609 * => The vnode must be locked. 610 */ 611 tmpfs_dirent_t * 612 tmpfs_dir_cached(tmpfs_node_t *node) 613 { 614 tmpfs_dirent_t *de = node->tn_dirent_hint; 615 616 KASSERT(VOP_ISLOCKED(node->tn_vnode)); 617 618 if (de == NULL) { 619 return NULL; 620 } 621 KASSERT(de->td_node == node); 622 623 /* 624 * Directories always have a valid hint. For files, check if there 625 * are any hard links. If there are - hint might be invalid. 626 */ 627 return (node->tn_type != VDIR && node->tn_links > 1) ? NULL : de; 628 } 629 630 /* 631 * tmpfs_dir_getseq: get a per-directory sequence number for the entry. 632 */ 633 uint64_t 634 tmpfs_dir_getseq(tmpfs_node_t *dnode, tmpfs_dirent_t *de) 635 { 636 uint64_t seq = de->td_seq; 637 638 TMPFS_VALIDATE_DIR(dnode); 639 640 if (__predict_true(seq != TMPFS_DIRSEQ_NONE)) { 641 /* Already set. */ 642 KASSERT(seq >= TMPFS_DIRSEQ_START); 643 return seq; 644 } 645 646 /* 647 * The "." and ".." and the end-of-directory have reserved numbers. 648 * The other sequence numbers are allocated incrementally. 649 */ 650 651 seq = dnode->tn_spec.tn_dir.tn_next_seq; 652 KASSERT(seq >= TMPFS_DIRSEQ_START); 653 KASSERT(seq < TMPFS_DIRSEQ_END); 654 dnode->tn_spec.tn_dir.tn_next_seq++; 655 return seq; 656 } 657 658 void 659 tmpfs_dir_putseq(tmpfs_node_t *dnode, tmpfs_dirent_t *de) 660 { 661 uint64_t seq = de->td_seq; 662 663 TMPFS_VALIDATE_DIR(dnode); 664 KASSERT(seq == TMPFS_DIRSEQ_NONE || seq >= TMPFS_DIRSEQ_START); 665 KASSERT(seq == TMPFS_DIRSEQ_NONE || seq < TMPFS_DIRSEQ_END); 666 667 de->td_seq = TMPFS_DIRSEQ_NONE; 668 669 /* Empty? We can reset. */ 670 if (dnode->tn_size == 0) { 671 dnode->tn_spec.tn_dir.tn_next_seq = TMPFS_DIRSEQ_START; 672 } else if (seq != TMPFS_DIRSEQ_NONE && 673 seq == dnode->tn_spec.tn_dir.tn_next_seq - 1) { 674 dnode->tn_spec.tn_dir.tn_next_seq--; 675 } 676 } 677 678 /* 679 * tmpfs_dir_lookupbyseq: lookup a directory entry by the sequence number. 680 */ 681 tmpfs_dirent_t * 682 tmpfs_dir_lookupbyseq(tmpfs_node_t *node, off_t seq) 683 { 684 tmpfs_dirent_t *de = node->tn_spec.tn_dir.tn_readdir_lastp; 685 686 TMPFS_VALIDATE_DIR(node); 687 688 /* 689 * First, check the cache. If does not match - perform a lookup. 690 */ 691 if (de && de->td_seq == seq) { 692 KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); 693 KASSERT(de->td_seq != TMPFS_DIRSEQ_NONE); 694 return de; 695 } 696 697 TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) { 698 KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); 699 KASSERT(de->td_seq != TMPFS_DIRSEQ_NONE); 700 if (de->td_seq == seq) 701 return de; 702 } 703 return NULL; 704 } 705 706 /* 707 * tmpfs_dir_getdotents: helper function for tmpfs_readdir() to get the 708 * dot meta entries, that is, "." or "..". Copy it to the UIO space. 709 */ 710 int 711 tmpfs_dir_getdotents(tmpfs_node_t *node, struct dirent *dp, struct uio *uio) 712 { 713 tmpfs_dirent_t *de; 714 off_t next = 0; 715 int error; 716 717 switch (uio->uio_offset) { 718 case TMPFS_DIRSEQ_DOT: 719 dp->d_fileno = node->tn_id; 720 strlcpy(dp->d_name, ".", sizeof(dp->d_name)); 721 next = TMPFS_DIRSEQ_DOTDOT; 722 break; 723 case TMPFS_DIRSEQ_DOTDOT: 724 dp->d_fileno = node->tn_spec.tn_dir.tn_parent->tn_id; 725 strlcpy(dp->d_name, "..", sizeof(dp->d_name)); 726 de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir); 727 next = de ? tmpfs_dir_getseq(node, de) : TMPFS_DIRSEQ_EOF; 728 break; 729 default: 730 KASSERT(false); 731 } 732 dp->d_type = DT_DIR; 733 dp->d_namlen = strlen(dp->d_name); 734 dp->d_reclen = DIRENT_SIZE(dp); 735 dp->d_off = next; 736 737 if (dp->d_reclen > uio->uio_resid) { 738 return EJUSTRETURN; 739 } 740 741 if ((error = uiomove(dp, dp->d_reclen, uio)) != 0) { 742 return error; 743 } 744 745 uio->uio_offset = next; 746 return error; 747 } 748 749 /* 750 * tmpfs_dir_getdents: helper function for tmpfs_readdir. 751 * 752 * => Returns as much directory entries as can fit in the uio space. 753 * => The read starts at uio->uio_offset. 754 */ 755 int 756 tmpfs_dir_getdents(tmpfs_node_t *node, struct uio *uio) 757 { 758 tmpfs_dirent_t *de, *next_de; 759 struct dirent dent; 760 int error = 0; 761 762 KASSERT(VOP_ISLOCKED(node->tn_vnode)); 763 TMPFS_VALIDATE_DIR(node); 764 memset(&dent, 0, sizeof(dent)); 765 766 if (uio->uio_offset == TMPFS_DIRSEQ_DOT) { 767 if ((error = tmpfs_dir_getdotents(node, &dent, uio)) != 0) { 768 goto done; 769 } 770 } 771 if (uio->uio_offset == TMPFS_DIRSEQ_DOTDOT) { 772 if ((error = tmpfs_dir_getdotents(node, &dent, uio)) != 0) { 773 goto done; 774 } 775 } 776 /* Done if we reached the end. */ 777 if (uio->uio_offset == TMPFS_DIRSEQ_EOF) { 778 goto done; 779 } 780 781 /* Locate the directory entry given by the given sequence number. */ 782 de = tmpfs_dir_lookupbyseq(node, uio->uio_offset); 783 if (de == NULL) { 784 error = EINVAL; 785 goto done; 786 } 787 788 /* 789 * Read as many entries as possible; i.e., until we reach the end 790 * of the directory or we exhaust UIO space. 791 */ 792 do { 793 dent.d_fileno = de->td_node->tn_id; 794 switch (de->td_node->tn_type) { 795 case VBLK: 796 dent.d_type = DT_BLK; 797 break; 798 case VCHR: 799 dent.d_type = DT_CHR; 800 break; 801 case VDIR: 802 dent.d_type = DT_DIR; 803 break; 804 case VFIFO: 805 dent.d_type = DT_FIFO; 806 break; 807 case VLNK: 808 dent.d_type = DT_LNK; 809 break; 810 case VREG: 811 dent.d_type = DT_REG; 812 break; 813 case VSOCK: 814 dent.d_type = DT_SOCK; 815 break; 816 default: 817 KASSERT(0); 818 } 819 dent.d_namlen = de->td_namelen; 820 KASSERT(de->td_namelen < sizeof(dent.d_name)); 821 memcpy(dent.d_name, de->td_name, de->td_namelen); 822 dent.d_name[de->td_namelen] = '\0'; 823 dent.d_reclen = DIRENT_SIZE(&dent); 824 825 next_de = TAILQ_NEXT(de, td_entries); 826 if (next_de == NULL) 827 dent.d_off = TMPFS_DIRSEQ_EOF; 828 else 829 dent.d_off = tmpfs_dir_getseq(node, next_de); 830 831 if (dent.d_reclen > uio->uio_resid) { 832 /* Exhausted UIO space. */ 833 error = EJUSTRETURN; 834 break; 835 } 836 837 /* Copy out the directory entry and continue. */ 838 error = uiomove(&dent, dent.d_reclen, uio); 839 if (error) { 840 break; 841 } 842 de = TAILQ_NEXT(de, td_entries); 843 844 } while (uio->uio_resid > 0 && de); 845 846 /* Cache the last entry or clear and mark EOF. */ 847 uio->uio_offset = de ? tmpfs_dir_getseq(node, de) : TMPFS_DIRSEQ_EOF; 848 node->tn_spec.tn_dir.tn_readdir_lastp = de; 849 done: 850 tmpfs_update(node, TMPFS_NODE_ACCESSED); 851 852 if (error == EJUSTRETURN) { 853 /* Exhausted UIO space - just return. */ 854 error = 0; 855 } 856 KASSERT(error >= 0); 857 return error; 858 } 859 860 /* 861 * tmpfs_reg_resize: resize the underlying UVM object associated with the 862 * specified regular file. 863 */ 864 865 int 866 tmpfs_reg_resize(struct vnode *vp, off_t newsize) 867 { 868 tmpfs_mount_t *tmp = VFS_TO_TMPFS(vp->v_mount); 869 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 870 struct uvm_object *uobj = node->tn_spec.tn_reg.tn_aobj; 871 size_t newpages, oldpages, bytes; 872 off_t oldsize; 873 vaddr_t pgoff; 874 int error; 875 876 KASSERT(vp->v_type == VREG); 877 KASSERT(newsize >= 0); 878 879 oldsize = node->tn_size; 880 oldpages = round_page(oldsize) >> PAGE_SHIFT; 881 newpages = round_page(newsize) >> PAGE_SHIFT; 882 KASSERT(oldpages == node->tn_spec.tn_reg.tn_aobj_pages); 883 884 if (newpages > oldpages) { 885 /* Increase the used-memory counter if getting extra pages. */ 886 bytes = (newpages - oldpages) << PAGE_SHIFT; 887 if (tmpfs_mem_incr(tmp, bytes) == 0) 888 return ENOSPC; 889 if (uao_grow(uobj, newpages) != 0) { 890 tmpfs_mem_decr(tmp, bytes); 891 return ENOSPC; 892 } 893 } 894 895 node->tn_spec.tn_reg.tn_aobj_pages = newpages; 896 node->tn_size = newsize; 897 uvm_vnp_setsize(vp, newsize); 898 uvm_vnp_uncache(vp); 899 900 /* 901 * Free "backing store". 902 */ 903 if (newpages < oldpages) { 904 if (tmpfs_uio_cached(node)) 905 tmpfs_uio_uncache(node); 906 if (uao_shrink(uobj, newpages)) 907 panic("shrink failed"); 908 /* Decrease the used-memory counter. */ 909 tmpfs_mem_decr(tmp, (oldpages - newpages) << PAGE_SHIFT); 910 } 911 if (newsize > oldsize) { 912 if (tmpfs_uio_cached(node)) 913 tmpfs_uio_uncache(node); 914 pgoff = oldsize & PAGE_MASK; 915 if (pgoff != 0) { 916 /* 917 * Growing from an offset which is not at a page 918 * boundary; zero out unused bytes in current page. 919 */ 920 error = tmpfs_zeropg(node, trunc_page(oldsize), pgoff); 921 if (error) 922 panic("tmpfs_zeropg: error %d", error); 923 } 924 VN_KNOTE(vp, NOTE_EXTEND); 925 } 926 return 0; 927 } 928 929 /* 930 * tmpfs_chflags: change flags of the given vnode. 931 * 932 */ 933 int 934 tmpfs_chflags(struct vnode *vp, int flags, struct ucred *cred, struct proc *p) 935 { 936 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 937 int error; 938 939 KASSERT(VOP_ISLOCKED(vp)); 940 941 /* Disallow this operation if the file system is mounted read-only. */ 942 if (vp->v_mount->mnt_flag & MNT_RDONLY) 943 return EROFS; 944 945 if (cred->cr_uid != node->tn_uid && (error = suser_ucred(cred))) 946 return error; 947 948 if (cred->cr_uid == 0) { 949 if (node->tn_flags & (SF_IMMUTABLE | SF_APPEND) && 950 securelevel > 0) 951 return EPERM; 952 node->tn_flags = flags; 953 } else { 954 if (node->tn_flags & (SF_IMMUTABLE | SF_APPEND) || 955 (flags & UF_SETTABLE) != flags) 956 return EPERM; 957 node->tn_flags &= SF_SETTABLE; 958 node->tn_flags |= (flags & UF_SETTABLE); 959 } 960 961 tmpfs_update(node, TMPFS_NODE_CHANGED); 962 VN_KNOTE(vp, NOTE_ATTRIB); 963 return 0; 964 } 965 966 /* 967 * tmpfs_chmod: change access mode on the given vnode. 968 * 969 */ 970 int 971 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct proc *p) 972 { 973 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 974 int error; 975 976 KASSERT(VOP_ISLOCKED(vp)); 977 978 /* Disallow this operation if the file system is mounted read-only. */ 979 if (vp->v_mount->mnt_flag & MNT_RDONLY) 980 return EROFS; 981 982 /* Immutable or append-only files cannot be modified, either. */ 983 if (node->tn_flags & (IMMUTABLE | APPEND)) 984 return EPERM; 985 986 if (cred->cr_uid != node->tn_uid && (error = suser_ucred(cred))) 987 return error; 988 if (cred->cr_uid != 0) { 989 if (vp->v_type != VDIR && (mode & S_ISTXT)) 990 return EFTYPE; 991 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) 992 return EPERM; 993 } 994 995 node->tn_mode = (mode & ALLPERMS); 996 tmpfs_update(node, TMPFS_NODE_CHANGED); 997 if ((vp->v_flag & VTEXT) && (node->tn_mode & S_ISTXT) == 0) 998 uvm_vnp_uncache(vp); 999 VN_KNOTE(vp, NOTE_ATTRIB); 1000 return 0; 1001 } 1002 1003 /* 1004 * tmpfs_chown: change ownership of the given vnode. 1005 * 1006 * => At least one of uid or gid must be different than VNOVAL. 1007 * => Attribute is unchanged for VNOVAL case. 1008 */ 1009 int 1010 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, struct proc *p) 1011 { 1012 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1013 int error; 1014 1015 KASSERT(VOP_ISLOCKED(vp)); 1016 1017 /* Assign default values if they are unknown. */ 1018 KASSERT(uid != VNOVAL || gid != VNOVAL); 1019 if (uid == VNOVAL) { 1020 uid = node->tn_uid; 1021 } 1022 if (gid == VNOVAL) { 1023 gid = node->tn_gid; 1024 } 1025 1026 /* Disallow this operation if the file system is mounted read-only. */ 1027 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1028 return EROFS; 1029 1030 /* Immutable or append-only files cannot be modified, either. */ 1031 if (node->tn_flags & (IMMUTABLE | APPEND)) 1032 return EPERM; 1033 1034 if ((cred->cr_uid != node->tn_uid || uid != node->tn_uid || 1035 (gid != node->tn_gid && !groupmember(gid, cred))) && 1036 (error = suser_ucred(cred))) 1037 return error; 1038 1039 node->tn_uid = uid; 1040 node->tn_gid = gid; 1041 tmpfs_update(node, TMPFS_NODE_CHANGED); 1042 VN_KNOTE(vp, NOTE_ATTRIB); 1043 return 0; 1044 } 1045 1046 /* 1047 * tmpfs_chsize: change size of the given vnode. 1048 */ 1049 int 1050 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, struct proc *p) 1051 { 1052 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1053 1054 KASSERT(VOP_ISLOCKED(vp)); 1055 1056 /* Decide whether this is a valid operation based on the file type. */ 1057 switch (vp->v_type) { 1058 case VDIR: 1059 return EISDIR; 1060 case VREG: 1061 if (vp->v_mount->mnt_flag & MNT_RDONLY) { 1062 return EROFS; 1063 } 1064 break; 1065 case VBLK: 1066 case VCHR: 1067 case VFIFO: 1068 /* 1069 * Allow modifications of special files even if in the file 1070 * system is mounted read-only (we are not modifying the 1071 * files themselves, but the objects they represent). 1072 */ 1073 return 0; 1074 default: 1075 return EOPNOTSUPP; 1076 } 1077 1078 /* Immutable or append-only files cannot be modified, either. */ 1079 if (node->tn_flags & (IMMUTABLE | APPEND)) { 1080 return EPERM; 1081 } 1082 1083 /* Note: tmpfs_truncate() will raise NOTE_EXTEND and NOTE_ATTRIB. */ 1084 return tmpfs_truncate(vp, size); 1085 } 1086 1087 /* 1088 * tmpfs_chtimes: change access and modification times for vnode. 1089 */ 1090 int 1091 tmpfs_chtimes(struct vnode *vp, const struct timespec *atime, 1092 const struct timespec *mtime, int vaflags, struct ucred *cred, 1093 struct proc *p) 1094 { 1095 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1096 int error; 1097 1098 KASSERT(VOP_ISLOCKED(vp)); 1099 1100 /* Disallow this operation if the file system is mounted read-only. */ 1101 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1102 return EROFS; 1103 1104 /* Immutable or append-only files cannot be modified, either. */ 1105 if (node->tn_flags & (IMMUTABLE | APPEND)) 1106 return EPERM; 1107 1108 if (cred->cr_uid != node->tn_uid && (error = suser_ucred(cred)) && 1109 ((vaflags & VA_UTIMES_NULL) == 0 || 1110 (error = VOP_ACCESS(vp, VWRITE, cred, p)))) 1111 return error; 1112 1113 if (atime->tv_nsec != VNOVAL) 1114 node->tn_atime = *atime; 1115 1116 if (mtime->tv_nsec != VNOVAL) 1117 node->tn_mtime = *mtime; 1118 1119 if (mtime->tv_nsec != VNOVAL || (vaflags & VA_UTIMES_CHANGE)) 1120 tmpfs_update(VP_TO_TMPFS_NODE(vp), TMPFS_NODE_CHANGED); 1121 1122 VN_KNOTE(vp, NOTE_ATTRIB); 1123 1124 return 0; 1125 } 1126 1127 /* 1128 * tmpfs_update: update timestamps, et al. 1129 */ 1130 void 1131 tmpfs_update(tmpfs_node_t *node, int flags) 1132 { 1133 struct timespec nowtm; 1134 1135 nanotime(&nowtm); 1136 1137 if (flags & TMPFS_NODE_ACCESSED) { 1138 node->tn_atime = nowtm; 1139 } 1140 if (flags & TMPFS_NODE_MODIFIED) { 1141 node->tn_mtime = nowtm; 1142 } 1143 if (flags & TMPFS_NODE_CHANGED) { 1144 node->tn_ctime = nowtm; 1145 } 1146 } 1147 1148 int 1149 tmpfs_truncate(struct vnode *vp, off_t length) 1150 { 1151 tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); 1152 int error; 1153 1154 if (length < 0) { 1155 error = EINVAL; 1156 goto out; 1157 } 1158 if (node->tn_size == length) { 1159 error = 0; 1160 goto out; 1161 } 1162 error = tmpfs_reg_resize(vp, length); 1163 if (error == 0) { 1164 tmpfs_update(node, TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED); 1165 } 1166 out: 1167 return error; 1168 } 1169 1170 int 1171 tmpfs_uio_cached(tmpfs_node_t *node) 1172 { 1173 int pgnum_valid = (node->tn_pgnum != (voff_t)-1); 1174 int pgptr_valid = (node->tn_pgptr != (vaddr_t)NULL); 1175 KASSERT(pgnum_valid == pgptr_valid); 1176 return pgnum_valid && pgptr_valid; 1177 } 1178 1179 vaddr_t 1180 tmpfs_uio_lookup(tmpfs_node_t *node, voff_t pgnum) 1181 { 1182 if (tmpfs_uio_cached(node) == 1 && node->tn_pgnum == pgnum) 1183 return node->tn_pgptr; 1184 1185 return (vaddr_t)NULL; 1186 } 1187 1188 void 1189 tmpfs_uio_uncache(tmpfs_node_t *node) 1190 { 1191 KASSERT(node->tn_pgnum != (voff_t)-1); 1192 KASSERT(node->tn_pgptr != (vaddr_t)NULL); 1193 uvm_unmap(kernel_map, node->tn_pgptr, node->tn_pgptr + PAGE_SIZE); 1194 node->tn_pgnum = (voff_t)-1; 1195 node->tn_pgptr = (vaddr_t)NULL; 1196 } 1197 1198 void 1199 tmpfs_uio_cache(tmpfs_node_t *node, voff_t pgnum, vaddr_t pgptr) 1200 { 1201 KASSERT(node->tn_pgnum == (voff_t)-1); 1202 KASSERT(node->tn_pgptr == (vaddr_t)NULL); 1203 node->tn_pgnum = pgnum; 1204 node->tn_pgptr = pgptr; 1205 } 1206 1207 /* 1208 * Be gentle to kernel_map, don't allow more than 4MB in a single transaction. 1209 */ 1210 #define TMPFS_UIO_MAXBYTES ((1 << 22) - PAGE_SIZE) 1211 1212 int 1213 tmpfs_uiomove(tmpfs_node_t *node, struct uio *uio, vsize_t len) 1214 { 1215 vaddr_t va, pgoff; 1216 int error, adv; 1217 voff_t pgnum; 1218 vsize_t sz; 1219 1220 pgnum = trunc_page(uio->uio_offset); 1221 pgoff = uio->uio_offset & PAGE_MASK; 1222 1223 if (pgoff + len < PAGE_SIZE) { 1224 va = tmpfs_uio_lookup(node, pgnum); 1225 if (va != (vaddr_t)NULL) 1226 return uiomove((void *)va + pgoff, len, uio); 1227 } 1228 1229 if (len >= TMPFS_UIO_MAXBYTES) { 1230 sz = TMPFS_UIO_MAXBYTES; 1231 adv = MADV_NORMAL; 1232 } else { 1233 sz = len; 1234 adv = MADV_SEQUENTIAL; 1235 } 1236 1237 if (tmpfs_uio_cached(node)) 1238 tmpfs_uio_uncache(node); 1239 1240 uao_reference(node->tn_uobj); 1241 1242 error = uvm_map(kernel_map, &va, round_page(pgoff + sz), node->tn_uobj, 1243 trunc_page(uio->uio_offset), 0, UVM_MAPFLAG(PROT_READ | PROT_WRITE, 1244 PROT_READ | PROT_WRITE, MAP_INHERIT_NONE, adv, 0)); 1245 if (error) { 1246 uao_detach(node->tn_uobj); /* Drop reference. */ 1247 return error; 1248 } 1249 1250 error = uiomove((void *)va + pgoff, sz, uio); 1251 if (error == 0 && pgoff + sz < PAGE_SIZE) 1252 tmpfs_uio_cache(node, pgnum, va); 1253 else 1254 uvm_unmap(kernel_map, va, va + round_page(pgoff + sz)); 1255 1256 return error; 1257 } 1258 1259 int 1260 tmpfs_zeropg(tmpfs_node_t *node, voff_t pgnum, vaddr_t pgoff) 1261 { 1262 vaddr_t va; 1263 int error; 1264 1265 KASSERT(tmpfs_uio_cached(node) == 0); 1266 1267 uao_reference(node->tn_uobj); 1268 1269 error = uvm_map(kernel_map, &va, PAGE_SIZE, node->tn_uobj, pgnum, 0, 1270 UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE, 1271 MAP_INHERIT_NONE, MADV_NORMAL, 0)); 1272 if (error) { 1273 uao_detach(node->tn_uobj); /* Drop reference. */ 1274 return error; 1275 } 1276 1277 bzero((void *)va + pgoff, PAGE_SIZE - pgoff); 1278 uvm_unmap(kernel_map, va, va + PAGE_SIZE); 1279 1280 return 0; 1281 } 1282 1283