1 /* $NetBSD: tmpfs_subr.c,v 1.17 2005/12/11 12:24:29 christos 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 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Efficient memory file system supporting functions. 42 */ 43 44 #include <sys/cdefs.h> 45 __KERNEL_RCSID(0, "$NetBSD: tmpfs_subr.c,v 1.17 2005/12/11 12:24:29 christos Exp $"); 46 47 #include <sys/param.h> 48 #include <sys/dirent.h> 49 #include <sys/event.h> 50 #include <sys/malloc.h> 51 #include <sys/mount.h> 52 #include <sys/namei.h> 53 #include <sys/time.h> 54 #include <sys/stat.h> 55 #include <sys/systm.h> 56 #include <sys/swap.h> 57 #include <sys/vnode.h> 58 59 #include <uvm/uvm.h> 60 61 #include <miscfs/specfs/specdev.h> 62 #include <fs/tmpfs/tmpfs.h> 63 #include <fs/tmpfs/tmpfs_fifoops.h> 64 #include <fs/tmpfs/tmpfs_specops.h> 65 #include <fs/tmpfs/tmpfs_vnops.h> 66 67 /* --------------------------------------------------------------------- */ 68 69 /* 70 * Allocates a new node of type 'type' inside the 'tmp' mount point, with 71 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', 72 * using the credentials of the process 'p'. 73 * 74 * If the node type is set to 'VDIR', then the parent parameter must point 75 * to the parent directory of the node being created. It may only be NULL 76 * while allocating the root node. 77 * 78 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter 79 * specifies the device the node represents. 80 * 81 * If the node type is set to 'VLNK', then the parameter target specifies 82 * the file name of the target file for the symbolic link that is being 83 * created. 84 * 85 * Note that new nodes are retrieved from the available list if it has 86 * items or, if it is empty, from the node pool as long as there is enough 87 * space to create them. 88 * 89 * Returns zero on success or an appropriate error code on failure. 90 */ 91 int 92 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type, 93 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, 94 char *target, dev_t rdev, struct proc *p, struct tmpfs_node **node) 95 { 96 struct tmpfs_node *nnode; 97 98 /* If the root directory of the 'tmp' file system is not yet 99 * allocated, this must be the request to do it. */ 100 KASSERT(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); 101 102 KASSERT(IFF(type == VLNK, target != NULL)); 103 KASSERT(IFF(type == VBLK || type == VCHR, rdev != VNOVAL)); 104 105 KASSERT(uid != VNOVAL && gid != VNOVAL && mode != VNOVAL); 106 107 nnode = NULL; 108 if (LIST_EMPTY(&tmp->tm_nodes_avail)) { 109 KASSERT(tmp->tm_nodes_last <= tmp->tm_nodes_max); 110 if (tmp->tm_nodes_last == tmp->tm_nodes_max) 111 return ENOSPC; 112 113 nnode = 114 (struct tmpfs_node *)TMPFS_POOL_GET(&tmp->tm_node_pool, 0); 115 if (nnode == NULL) 116 return ENOSPC; 117 nnode->tn_id = tmp->tm_nodes_last++; 118 nnode->tn_gen = 0; 119 } else { 120 nnode = LIST_FIRST(&tmp->tm_nodes_avail); 121 LIST_REMOVE(nnode, tn_entries); 122 nnode->tn_gen++; 123 } 124 KASSERT(nnode != NULL); 125 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); 126 127 /* Generic initialization. */ 128 nnode->tn_type = type; 129 nnode->tn_size = 0; 130 nnode->tn_status = 0; 131 nnode->tn_flags = 0; 132 nnode->tn_links = 0; 133 (void)nanotime(&nnode->tn_atime); 134 nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = 135 nnode->tn_atime; 136 nnode->tn_uid = uid; 137 nnode->tn_gid = gid; 138 nnode->tn_mode = mode; 139 nnode->tn_lockf = NULL; 140 nnode->tn_vnode = NULL; 141 142 /* Type-specific initialization. */ 143 switch (nnode->tn_type) { 144 case VBLK: 145 case VCHR: 146 nnode->tn_rdev = rdev; 147 break; 148 149 case VDIR: 150 TAILQ_INIT(&nnode->tn_dir); 151 nnode->tn_parent = (parent == NULL) ? nnode : parent; 152 nnode->tn_readdir_lastn = 0; 153 nnode->tn_readdir_lastp = NULL; 154 nnode->tn_links++; 155 nnode->tn_parent->tn_links++; 156 break; 157 158 case VFIFO: 159 /* FALLTHROUGH */ 160 case VSOCK: 161 break; 162 163 case VLNK: 164 KASSERT(strlen(target) < MAXPATHLEN); 165 nnode->tn_size = strlen(target); 166 nnode->tn_link = tmpfs_str_pool_get(&tmp->tm_str_pool, 167 nnode->tn_size, 0); 168 if (nnode->tn_link == NULL) { 169 nnode->tn_type = VNON; 170 tmpfs_free_node(tmp, nnode); 171 return ENOSPC; 172 } 173 memcpy(nnode->tn_link, target, nnode->tn_size); 174 break; 175 176 case VREG: 177 nnode->tn_aobj = uao_create(INT32_MAX - PAGE_SIZE, 0); 178 nnode->tn_aobj_pages = 0; 179 break; 180 181 default: 182 KASSERT(0); 183 } 184 185 *node = nnode; 186 return 0; 187 } 188 189 /* --------------------------------------------------------------------- */ 190 191 /* 192 * Destroys the node pointed to by node from the file system 'tmp'. 193 * If the node does not belong to the given mount point, the results are 194 * unpredicted. 195 * 196 * If the node references a directory; no entries are allowed because 197 * their removal could need a recursive algorithm, something forbidden in 198 * kernel space. Furthermore, there is not need to provide such 199 * functionality (recursive removal) because the only primitives offered 200 * to the user are the removal of empty directories and the deletion of 201 * individual files. 202 * 203 * Note that nodes are not really deleted; in fact, when a node has been 204 * allocated, it cannot be deleted during the whole life of the file 205 * system. Instead, they are moved to the available list and remain there 206 * until reused. 207 */ 208 void 209 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) 210 { 211 ino_t id; 212 unsigned long gen; 213 size_t pages; 214 215 switch (node->tn_type) { 216 case VNON: 217 /* Do not do anything. VNON is provided to let the 218 * allocation routine clean itself easily by avoiding 219 * duplicating code in it. */ 220 /* FALLTHROUGH */ 221 case VBLK: 222 /* FALLTHROUGH */ 223 case VCHR: 224 /* FALLTHROUGH */ 225 case VDIR: 226 /* FALLTHROUGH */ 227 case VFIFO: 228 /* FALLTHROUGH */ 229 case VSOCK: 230 pages = 0; 231 break; 232 233 case VLNK: 234 tmpfs_str_pool_put(&tmp->tm_str_pool, node->tn_link, 235 node->tn_size); 236 pages = 0; 237 break; 238 239 case VREG: 240 if (node->tn_aobj != NULL) 241 uao_detach(node->tn_aobj); 242 pages = node->tn_aobj_pages; 243 break; 244 245 default: 246 KASSERT(0); 247 pages = 0; /* Shut up gcc when !DIAGNOSTIC. */ 248 break; 249 } 250 251 tmp->tm_pages_used -= pages; 252 253 LIST_REMOVE(node, tn_entries); 254 id = node->tn_id; 255 gen = node->tn_gen; 256 memset(node, 0, sizeof(struct tmpfs_node)); 257 node->tn_id = id; 258 node->tn_type = VNON; 259 node->tn_gen = gen; 260 LIST_INSERT_HEAD(&tmp->tm_nodes_avail, node, tn_entries); 261 } 262 263 /* --------------------------------------------------------------------- */ 264 265 /* 266 * Allocates a new directory entry for the node node with a name of name. 267 * The new directory entry is returned in *de. 268 * 269 * The link count of node is increased by one to reflect the new object 270 * referencing it. 271 * 272 * Returns zero on success or an appropriate error code on failure. 273 */ 274 int 275 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, 276 const char *name, uint16_t len, struct tmpfs_dirent **de) 277 { 278 struct tmpfs_dirent *nde; 279 280 nde = (struct tmpfs_dirent *)TMPFS_POOL_GET(&tmp->tm_dirent_pool, 0); 281 if (nde == NULL) 282 return ENOSPC; 283 284 nde->td_name = tmpfs_str_pool_get(&tmp->tm_str_pool, len, 0); 285 if (nde->td_name == NULL) { 286 TMPFS_POOL_PUT(&tmp->tm_dirent_pool, nde); 287 return ENOSPC; 288 } 289 nde->td_namelen = len; 290 memcpy(nde->td_name, name, len); 291 nde->td_node = node; 292 293 node->tn_links++; 294 *de = nde; 295 296 return 0; 297 } 298 299 /* --------------------------------------------------------------------- */ 300 301 /* 302 * Frees a directory entry. It is the caller's responsibility to destroy 303 * the node referenced by it if needed. 304 * 305 * The link count of node is decreased by one to reflect the removal of an 306 * object that referenced it. This only happens if 'node_exists' is true; 307 * otherwise the function will not access the node referred to by the 308 * directory entry, as it may already have been released from the outside. 309 */ 310 void 311 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de, 312 boolean_t node_exists) 313 { 314 if (node_exists) { 315 struct tmpfs_node *node; 316 317 node = de->td_node; 318 319 KASSERT(node->tn_links > 0); 320 node->tn_links--; 321 } 322 323 tmpfs_str_pool_put(&tmp->tm_str_pool, de->td_name, de->td_namelen); 324 TMPFS_POOL_PUT(&tmp->tm_dirent_pool, de); 325 } 326 327 /* --------------------------------------------------------------------- */ 328 329 /* 330 * Allocates a new vnode for the node node or returns a new reference to 331 * an existing one if the node had already a vnode referencing it. The 332 * resulting locked vnode is returned in *vpp. 333 * 334 * Returns zero on success or an appropriate error code on failure. 335 */ 336 int 337 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, struct vnode **vpp) 338 { 339 int error; 340 struct vnode *nvp; 341 struct vnode *vp; 342 343 vp = NULL; 344 345 if (node->tn_vnode != NULL) { 346 vp = node->tn_vnode; 347 vget(vp, LK_EXCLUSIVE | LK_RETRY); 348 error = 0; 349 goto out; 350 } 351 352 /* Get a new vnode and associate it with our node. */ 353 error = getnewvnode(VT_TMPFS, mp, tmpfs_vnodeop_p, &vp); 354 if (error != 0) 355 goto out; 356 KASSERT(vp != NULL); 357 358 error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 359 if (error != 0) { 360 vp->v_data = NULL; 361 ungetnewvnode(vp); 362 vp = NULL; 363 goto out; 364 } 365 366 vp->v_data = node; 367 vp->v_type = node->tn_type; 368 369 /* Type-specific initialization. */ 370 switch (node->tn_type) { 371 case VBLK: 372 /* FALLTHROUGH */ 373 case VCHR: 374 vp->v_op = tmpfs_specop_p; 375 nvp = checkalias(vp, node->tn_rdev, mp); 376 if (nvp != NULL) { 377 /* Discard unneeded vnode, but save its inode. */ 378 nvp->v_data = vp->v_data; 379 vp->v_data = NULL; 380 381 /* XXX spec_vnodeops has no locking, so we have to 382 * do it explicitly. */ 383 VOP_UNLOCK(vp, 0); 384 vp->v_op = spec_vnodeop_p; 385 vp->v_flag &= ~VLOCKSWORK; 386 vrele(vp); 387 vgone(vp); 388 389 /* Reinitialize aliased node. */ 390 vp = nvp; 391 error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 392 if (error != 0) { 393 vp->v_data = NULL; 394 vp = NULL; 395 goto out; 396 } 397 } 398 break; 399 400 case VDIR: 401 vp->v_flag = node->tn_parent == node ? VROOT : 0; 402 break; 403 404 case VFIFO: 405 vp->v_op = tmpfs_fifoop_p; 406 break; 407 408 case VLNK: 409 /* FALLTHROUGH */ 410 case VREG: 411 /* FALLTHROUGH */ 412 case VSOCK: 413 break; 414 415 default: 416 KASSERT(0); 417 } 418 419 uvm_vnp_setsize(vp, node->tn_size); 420 421 error = 0; 422 423 out: 424 *vpp = node->tn_vnode = vp; 425 426 KASSERT(IFF(error == 0, *vpp != NULL && VOP_ISLOCKED(*vpp))); 427 KASSERT(*vpp == node->tn_vnode); 428 429 return error; 430 } 431 432 /* --------------------------------------------------------------------- */ 433 434 /* 435 * Destroys the association between the vnode vp and the node it 436 * references. 437 */ 438 void 439 tmpfs_free_vp(struct vnode *vp) 440 { 441 struct tmpfs_node *node; 442 443 node = VP_TO_TMPFS_NODE(vp); 444 445 node->tn_vnode = NULL; 446 vp->v_data = NULL; 447 } 448 449 /* --------------------------------------------------------------------- */ 450 451 /* 452 * Allocates a new file of type 'type' and adds it to the parent directory 453 * 'dvp'; this addition is done using the component name given in 'cnp'. 454 * The ownership of the new file is automatically assigned based on the 455 * credentials of the caller (through 'cnp'), the group is set based on 456 * the parent directory and the mode is determined from the 'vap' argument. 457 * If successful, *vpp holds a vnode to the newly created file and zero 458 * is returned. Otherwise *vpp is NULL and the function returns an 459 * appropriate error code. 460 */ 461 int 462 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, 463 struct componentname *cnp, char *target) 464 { 465 int error; 466 struct tmpfs_dirent *de; 467 struct tmpfs_mount *tmp; 468 struct tmpfs_node *dnode; 469 struct tmpfs_node *node; 470 struct tmpfs_node *parent; 471 472 KASSERT(VOP_ISLOCKED(dvp)); 473 KASSERT(cnp->cn_flags & HASBUF); 474 475 tmp = VFS_TO_TMPFS(dvp->v_mount); 476 dnode = VP_TO_TMPFS_DIR(dvp); 477 *vpp = NULL; 478 479 /* If the entry we are creating is a directory, we cannot overflow 480 * the number of links of its parent, because it will get a new 481 * link. */ 482 if (vap->va_type == VDIR) { 483 /* Ensure that we do not overflow the maximum number of links 484 * imposed by the system. */ 485 KASSERT(dnode->tn_links <= LINK_MAX); 486 if (dnode->tn_links == LINK_MAX) { 487 error = EMLINK; 488 goto out; 489 } 490 491 parent = dnode; 492 } else 493 parent = NULL; 494 495 /* Allocate a node that represents the new file. */ 496 error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid, 497 dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, 498 cnp->cn_lwp->l_proc, &node); 499 if (error != 0) 500 goto out; 501 502 /* Allocate a directory entry that points to the new file. */ 503 error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, 504 &de); 505 if (error != 0) { 506 tmpfs_free_node(tmp, node); 507 goto out; 508 } 509 510 /* Allocate a vnode for the new file. */ 511 error = tmpfs_alloc_vp(dvp->v_mount, node, vpp); 512 if (error != 0) { 513 tmpfs_free_dirent(tmp, de, TRUE); 514 tmpfs_free_node(tmp, node); 515 goto out; 516 } 517 518 /* Now that all required items are allocated, we can proceed to 519 * insert the new node into the directory, an operation that 520 * cannot fail. */ 521 tmpfs_dir_attach(dvp, de); 522 VN_KNOTE(dvp, NOTE_WRITE); 523 524 out: 525 if (error != 0 || !(cnp->cn_flags & SAVESTART)) 526 PNBUF_PUT(cnp->cn_pnbuf); 527 vput(dvp); 528 529 KASSERT(!VOP_ISLOCKED(dvp)); 530 KASSERT(IFF(error == 0, *vpp != NULL)); 531 532 return error; 533 } 534 535 /* --------------------------------------------------------------------- */ 536 537 /* 538 * Attaches the directory entry de to the directory represented by vp. 539 * Note that this does not change the link count of the node pointed by 540 * the directory entry, as this is done by tmpfs_alloc_dirent. 541 */ 542 void 543 tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) 544 { 545 struct tmpfs_node *dnode; 546 547 dnode = VP_TO_TMPFS_DIR(vp); 548 549 TAILQ_INSERT_TAIL(&dnode->tn_dir, de, td_entries); 550 dnode->tn_size += sizeof(struct tmpfs_dirent); 551 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 552 TMPFS_NODE_MODIFIED; 553 uvm_vnp_setsize(vp, dnode->tn_size); 554 } 555 556 /* --------------------------------------------------------------------- */ 557 558 /* 559 * Detaches the directory entry de from the directory represented by vp. 560 * Note that this does not change the link count of the node pointed by 561 * the directory entry, as this is done by tmpfs_free_dirent. 562 */ 563 void 564 tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) 565 { 566 struct tmpfs_node *dnode; 567 568 KASSERT(VOP_ISLOCKED(vp)); 569 570 dnode = VP_TO_TMPFS_DIR(vp); 571 572 if (dnode->tn_readdir_lastp == de) { 573 dnode->tn_readdir_lastn = 0; 574 dnode->tn_readdir_lastp = NULL; 575 } 576 577 TAILQ_REMOVE(&dnode->tn_dir, de, td_entries); 578 dnode->tn_size -= sizeof(struct tmpfs_dirent); 579 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ 580 TMPFS_NODE_MODIFIED; 581 uvm_vnp_setsize(vp, dnode->tn_size); 582 } 583 584 /* --------------------------------------------------------------------- */ 585 586 /* 587 * Looks for a directory entry in the directory represented by node. 588 * 'cnp' describes the name of the entry to look for. Note that the . 589 * and .. components are not allowed as they do not physically exist 590 * within directories. 591 * 592 * Returns a pointer to the entry when found, otherwise NULL. 593 */ 594 struct tmpfs_dirent * 595 tmpfs_dir_lookup(struct tmpfs_node *node, struct componentname *cnp) 596 { 597 boolean_t found; 598 struct tmpfs_dirent *de; 599 600 KASSERT(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); 601 KASSERT(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && 602 cnp->cn_nameptr[1] == '.'))); 603 TMPFS_VALIDATE_DIR(node); 604 605 node->tn_status |= TMPFS_NODE_ACCESSED; 606 607 found = 0; 608 TAILQ_FOREACH(de, &node->tn_dir, td_entries) { 609 KASSERT(cnp->cn_namelen < 0xffff); 610 if (de->td_namelen == (uint16_t)cnp->cn_namelen && 611 memcmp(de->td_name, cnp->cn_nameptr, de->td_namelen) == 0) { 612 found = 1; 613 break; 614 } 615 } 616 617 return found ? de : NULL; 618 } 619 620 /* --------------------------------------------------------------------- */ 621 622 /* 623 * Helper function for tmpfs_readdir. Creates a '.' entry for the given 624 * directory and returns it in the uio space. The function returns 0 625 * on success, -1 if there was not enough space in the uio structure to 626 * hold the directory entry or an appropriate error code if another 627 * error happens. 628 */ 629 int 630 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) 631 { 632 int error; 633 struct dirent dent; 634 635 TMPFS_VALIDATE_DIR(node); 636 KASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); 637 638 dent.d_fileno = node->tn_id; 639 dent.d_type = DT_DIR; 640 dent.d_namlen = 1; 641 dent.d_name[0] = '.'; 642 dent.d_name[1] = '\0'; 643 dent.d_reclen = _DIRENT_SIZE(&dent); 644 645 if (dent.d_reclen > uio->uio_resid) 646 error = -1; 647 else { 648 error = uiomove(&dent, dent.d_reclen, uio); 649 if (error == 0) 650 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 651 } 652 653 node->tn_status |= TMPFS_NODE_ACCESSED; 654 655 return error; 656 } 657 658 /* --------------------------------------------------------------------- */ 659 660 /* 661 * Helper function for tmpfs_readdir. Creates a '..' entry for the given 662 * directory and returns it in the uio space. The function returns 0 663 * on success, -1 if there was not enough space in the uio structure to 664 * hold the directory entry or an appropriate error code if another 665 * error happens. 666 */ 667 int 668 tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio) 669 { 670 int error; 671 struct dirent dent; 672 673 TMPFS_VALIDATE_DIR(node); 674 KASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); 675 676 dent.d_fileno = node->tn_parent->tn_id; 677 dent.d_type = DT_DIR; 678 dent.d_namlen = 2; 679 dent.d_name[0] = '.'; 680 dent.d_name[1] = '.'; 681 dent.d_name[2] = '\0'; 682 dent.d_reclen = _DIRENT_SIZE(&dent); 683 684 if (dent.d_reclen > uio->uio_resid) 685 error = -1; 686 else { 687 error = uiomove(&dent, dent.d_reclen, uio); 688 if (error == 0) { 689 struct tmpfs_dirent *de; 690 691 de = TAILQ_FIRST(&node->tn_dir); 692 if (de == NULL) 693 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 694 else 695 uio->uio_offset = TMPFS_DIRCOOKIE(de); 696 } 697 } 698 699 node->tn_status |= TMPFS_NODE_ACCESSED; 700 701 return error; 702 } 703 704 /* --------------------------------------------------------------------- */ 705 706 /* 707 * Lookup a directory entry by its associated cookie. 708 */ 709 struct tmpfs_dirent * 710 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie) 711 { 712 struct tmpfs_dirent *de; 713 714 if (cookie == node->tn_readdir_lastn && 715 node->tn_readdir_lastp != NULL) { 716 return node->tn_readdir_lastp; 717 } 718 719 TAILQ_FOREACH(de, &node->tn_dir, td_entries) { 720 if (TMPFS_DIRCOOKIE(de) == cookie) { 721 break; 722 } 723 } 724 725 return de; 726 } 727 728 /* --------------------------------------------------------------------- */ 729 730 /* 731 * Helper function for tmpfs_readdir. Returns as much directory entries 732 * as can fit in the uio space. The read starts at uio->uio_offset. 733 * The function returns 0 on success, -1 if there was not enough space 734 * in the uio structure to hold the directory entry or an appropriate 735 * error code if another error happens. 736 */ 737 int 738 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp) 739 { 740 int error; 741 off_t startcookie; 742 struct tmpfs_dirent *de; 743 744 TMPFS_VALIDATE_DIR(node); 745 746 /* Locate the first directory entry we have to return. We have cached 747 * the last readdir in the node, so use those values if appropriate. 748 * Otherwise do a linear scan to find the requested entry. */ 749 startcookie = uio->uio_offset; 750 KASSERT(startcookie != TMPFS_DIRCOOKIE_DOT); 751 KASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT); 752 if (startcookie == TMPFS_DIRCOOKIE_EOF) { 753 return 0; 754 } else { 755 de = tmpfs_dir_lookupbycookie(node, startcookie); 756 } 757 if (de == NULL) { 758 return EINVAL; 759 } 760 761 /* Read as much entries as possible; i.e., until we reach the end of 762 * the directory or we exhaust uio space. */ 763 do { 764 struct dirent d; 765 766 /* Create a dirent structure representing the current 767 * tmpfs_node and fill it. */ 768 d.d_fileno = de->td_node->tn_id; 769 switch (de->td_node->tn_type) { 770 case VBLK: 771 d.d_type = DT_BLK; 772 break; 773 774 case VCHR: 775 d.d_type = DT_CHR; 776 break; 777 778 case VDIR: 779 d.d_type = DT_DIR; 780 break; 781 782 case VFIFO: 783 d.d_type = DT_FIFO; 784 break; 785 786 case VLNK: 787 d.d_type = DT_LNK; 788 break; 789 790 case VREG: 791 d.d_type = DT_REG; 792 break; 793 794 case VSOCK: 795 d.d_type = DT_SOCK; 796 break; 797 798 default: 799 KASSERT(0); 800 } 801 d.d_namlen = de->td_namelen; 802 KASSERT(de->td_namelen < sizeof(d.d_name)); 803 (void)memcpy(d.d_name, de->td_name, de->td_namelen); 804 d.d_name[de->td_namelen] = '\0'; 805 d.d_reclen = _DIRENT_SIZE(&d); 806 807 /* Stop reading if the directory entry we are treating is 808 * bigger than the amount of data that can be returned. */ 809 if (d.d_reclen > uio->uio_resid) { 810 error = -1; 811 break; 812 } 813 814 /* Copy the new dirent structure into the output buffer and 815 * advance pointers. */ 816 error = uiomove(&d, d.d_reclen, uio); 817 818 (*cntp)++; 819 de = TAILQ_NEXT(de, td_entries); 820 } while (error == 0 && uio->uio_resid > 0 && de != NULL); 821 822 /* Update the offset and cache. */ 823 if (de == NULL) { 824 uio->uio_offset = TMPFS_DIRCOOKIE_EOF; 825 node->tn_readdir_lastn = 0; 826 node->tn_readdir_lastp = NULL; 827 } else { 828 node->tn_readdir_lastn = uio->uio_offset = TMPFS_DIRCOOKIE(de); 829 node->tn_readdir_lastp = de; 830 } 831 832 node->tn_status |= TMPFS_NODE_ACCESSED; 833 834 return error; 835 } 836 837 /* --------------------------------------------------------------------- */ 838 839 /* 840 * Resizes the aobj associated to the regular file pointed to by vp to 841 * the size newsize. 'vp' must point to a vnode that represents a regular 842 * file. 'newsize' must be positive. 843 * 844 * Returns zero on success or an appropriate error code on failure. 845 */ 846 int 847 tmpfs_reg_resize(struct vnode *vp, off_t newsize) 848 { 849 int error; 850 size_t newpages, oldpages; 851 struct tmpfs_mount *tmp; 852 struct tmpfs_node *node; 853 off_t oldsize; 854 855 KASSERT(vp->v_type == VREG); 856 KASSERT(newsize >= 0); 857 858 node = VP_TO_TMPFS_NODE(vp); 859 tmp = VFS_TO_TMPFS(vp->v_mount); 860 861 /* Convert the old and new sizes to the number of pages needed to 862 * store them. It may happen that we do not need to do anything 863 * because the last allocated page can accommodate the change on 864 * its own. */ 865 oldsize = node->tn_size; 866 oldpages = round_page(oldsize) / PAGE_SIZE; 867 KASSERT(oldpages == node->tn_aobj_pages); 868 newpages = round_page(newsize) / PAGE_SIZE; 869 870 if (newpages > oldpages && 871 newpages - oldpages > TMPFS_PAGES_AVAIL(tmp)) { 872 error = ENOSPC; 873 goto out; 874 } 875 876 node->tn_aobj_pages = newpages; 877 878 tmp->tm_pages_used += (newpages - oldpages); 879 node->tn_size = newsize; 880 uvm_vnp_setsize(vp, newsize); 881 if (newsize < oldsize) { 882 int zerolen = MIN(round_page(newsize), node->tn_size) - newsize; 883 884 /* 885 * free "backing store" 886 */ 887 888 if (newpages < oldpages) { 889 struct uvm_object *uobj = node->tn_aobj; 890 891 simple_lock(&uobj->vmobjlock); 892 uao_dropswap_range(uobj, newpages, oldpages); 893 simple_unlock(&uobj->vmobjlock); 894 } 895 896 /* 897 * zero out the truncated part of the last page. 898 */ 899 900 uvm_vnp_zerorange(vp, newsize, zerolen); 901 } 902 903 error = 0; 904 905 out: 906 return error; 907 } 908 909 /* --------------------------------------------------------------------- */ 910 911 /* 912 * Returns information about the number of available memory pages, 913 * including physical and virtual ones. 914 * 915 * If 'total' is TRUE, the value returned is the total amount of memory 916 * pages configured for the system (either in use or free). 917 * If it is FALSE, the value returned is the amount of free memory pages. 918 * 919 * Remember to remove TMPFS_PAGES_RESERVED from the returned value to avoid 920 * excessive memory usage. 921 * 922 */ 923 size_t 924 tmpfs_mem_info(boolean_t total) 925 { 926 size_t size; 927 928 size = 0; 929 size += uvmexp.swpgavail; 930 if (!total) { 931 size -= uvmexp.swpgonly; 932 } 933 size += uvmexp.free; 934 size += uvmexp.filepages; 935 if (size > uvmexp.wired) { 936 size -= uvmexp.wired; 937 } else { 938 size = 0; 939 } 940 941 return size; 942 } 943 944 /* --------------------------------------------------------------------- */ 945 946 /* 947 * Change flags of the given vnode. 948 * Caller should execute tmpfs_update on vp after a successful execution. 949 * The vnode must be locked on entry and remain locked on exit. 950 */ 951 int 952 tmpfs_chflags(struct vnode *vp, int flags, struct ucred *cred, struct proc *p) 953 { 954 int error; 955 struct tmpfs_node *node; 956 957 KASSERT(VOP_ISLOCKED(vp)); 958 959 node = VP_TO_TMPFS_NODE(vp); 960 961 /* Disallow this operation if the file system is mounted read-only. */ 962 if (vp->v_mount->mnt_flag & MNT_RDONLY) 963 return EROFS; 964 965 /* XXX: The following comes from UFS code, and can be found in 966 * several other file systems. Shouldn't this be centralized 967 * somewhere? */ 968 if (cred->cr_uid != node->tn_uid && 969 (error = suser(cred, &p->p_acflag))) 970 return error; 971 if (cred->cr_uid == 0) { 972 /* The super-user is only allowed to change flags if the file 973 * wasn't protected before and the securelevel is zero. */ 974 if ((node->tn_flags & (SF_IMMUTABLE | SF_APPEND)) && 975 securelevel > 0) 976 return EPERM; 977 node->tn_flags = flags; 978 } else { 979 /* Regular users can change flags provided they only want to 980 * change user-specific ones, not those reserved for the 981 * super-user. */ 982 if ((node->tn_flags & (SF_IMMUTABLE | SF_APPEND)) || 983 (flags & UF_SETTABLE) != flags) 984 return EPERM; 985 if ((node->tn_flags & SF_SETTABLE) != (flags & SF_SETTABLE)) 986 return EPERM; 987 node->tn_flags &= SF_SETTABLE; 988 node->tn_flags |= (flags & UF_SETTABLE); 989 } 990 991 node->tn_status |= TMPFS_NODE_CHANGED; 992 VN_KNOTE(vp, NOTE_ATTRIB); 993 994 KASSERT(VOP_ISLOCKED(vp)); 995 996 return 0; 997 } 998 999 /* --------------------------------------------------------------------- */ 1000 1001 /* 1002 * Change access mode on the given vnode. 1003 * Caller should execute tmpfs_update on vp after a successful execution. 1004 * The vnode must be locked on entry and remain locked on exit. 1005 */ 1006 int 1007 tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct proc *p) 1008 { 1009 int error; 1010 struct tmpfs_node *node; 1011 1012 KASSERT(VOP_ISLOCKED(vp)); 1013 1014 node = VP_TO_TMPFS_NODE(vp); 1015 1016 /* Disallow this operation if the file system is mounted read-only. */ 1017 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1018 return EROFS; 1019 1020 /* Immutable or append-only files cannot be modified, either. */ 1021 if (node->tn_flags & (IMMUTABLE | APPEND)) 1022 return EPERM; 1023 1024 /* XXX: The following comes from UFS code, and can be found in 1025 * several other file systems. Shouldn't this be centralized 1026 * somewhere? */ 1027 if (cred->cr_uid != node->tn_uid && 1028 (error = suser(cred, &p->p_acflag))) 1029 return error; 1030 if (cred->cr_uid != 0) { 1031 if (vp->v_type != VDIR && (mode & S_ISTXT)) 1032 return EFTYPE; 1033 1034 if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) 1035 return EPERM; 1036 } 1037 1038 node->tn_mode = (mode & ALLPERMS); 1039 1040 node->tn_status |= TMPFS_NODE_CHANGED; 1041 VN_KNOTE(vp, NOTE_ATTRIB); 1042 1043 KASSERT(VOP_ISLOCKED(vp)); 1044 1045 return 0; 1046 } 1047 1048 /* --------------------------------------------------------------------- */ 1049 1050 /* 1051 * Change ownership of the given vnode. At least one of uid or gid must 1052 * be different than VNOVAL. If one is set to that value, the attribute 1053 * is unchanged. 1054 * Caller should execute tmpfs_update on vp after a successful execution. 1055 * The vnode must be locked on entry and remain locked on exit. 1056 */ 1057 int 1058 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, 1059 struct proc *p) 1060 { 1061 int error; 1062 struct tmpfs_node *node; 1063 1064 KASSERT(VOP_ISLOCKED(vp)); 1065 1066 node = VP_TO_TMPFS_NODE(vp); 1067 1068 /* Assign default values if they are unknown. */ 1069 KASSERT(uid != VNOVAL || gid != VNOVAL); 1070 if (uid == VNOVAL) 1071 uid = node->tn_uid; 1072 if (gid == VNOVAL) 1073 gid = node->tn_gid; 1074 KASSERT(uid != VNOVAL && gid != VNOVAL); 1075 1076 /* Disallow this operation if the file system is mounted read-only. */ 1077 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1078 return EROFS; 1079 1080 /* Immutable or append-only files cannot be modified, either. */ 1081 if (node->tn_flags & (IMMUTABLE | APPEND)) 1082 return EPERM; 1083 1084 /* XXX: The following comes from UFS code, and can be found in 1085 * several other file systems. Shouldn't this be centralized 1086 * somewhere? */ 1087 if ((cred->cr_uid != node->tn_uid || uid != node->tn_uid || 1088 (gid != node->tn_gid && !(cred->cr_gid == node->tn_gid || 1089 groupmember(gid, cred)))) && 1090 ((error = suser(cred, &p->p_acflag)) != 0)) 1091 return error; 1092 1093 node->tn_uid = uid; 1094 node->tn_gid = gid; 1095 1096 node->tn_status |= TMPFS_NODE_CHANGED; 1097 VN_KNOTE(vp, NOTE_ATTRIB); 1098 1099 KASSERT(VOP_ISLOCKED(vp)); 1100 1101 return 0; 1102 } 1103 1104 /* --------------------------------------------------------------------- */ 1105 1106 /* 1107 * Change size of the given vnode. 1108 * Caller should execute tmpfs_update on vp after a successful execution. 1109 * The vnode must be locked on entry and remain locked on exit. 1110 */ 1111 int 1112 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, 1113 struct proc *p) 1114 { 1115 int error; 1116 struct tmpfs_node *node; 1117 1118 KASSERT(VOP_ISLOCKED(vp)); 1119 1120 node = VP_TO_TMPFS_NODE(vp); 1121 1122 /* Decide whether this is a valid operation based on the file type. */ 1123 error = 0; 1124 switch (vp->v_type) { 1125 case VDIR: 1126 return EISDIR; 1127 1128 case VREG: 1129 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1130 return EROFS; 1131 break; 1132 1133 case VBLK: 1134 /* FALLTHROUGH */ 1135 case VCHR: 1136 /* FALLTHROUGH */ 1137 case VFIFO: 1138 /* Allow modifications of special files even if in the file 1139 * system is mounted read-only (we are not modifying the 1140 * files themselves, but the objects they represent). */ 1141 return 0; 1142 1143 default: 1144 /* Anything else is unsupported. */ 1145 return EOPNOTSUPP; 1146 } 1147 1148 /* Immutable or append-only files cannot be modified, either. */ 1149 if (node->tn_flags & (IMMUTABLE | APPEND)) 1150 return EPERM; 1151 1152 error = tmpfs_truncate(vp, size); 1153 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents 1154 * for us, as will update tn_status; no need to do that here. */ 1155 1156 KASSERT(VOP_ISLOCKED(vp)); 1157 1158 return error; 1159 } 1160 1161 /* --------------------------------------------------------------------- */ 1162 1163 /* 1164 * Change access and modification times of the given vnode. 1165 * Caller should execute tmpfs_update on vp after a successful execution. 1166 * The vnode must be locked on entry and remain locked on exit. 1167 */ 1168 int 1169 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime, 1170 int vaflags, struct ucred *cred, struct lwp *l) 1171 { 1172 int error; 1173 struct tmpfs_node *node; 1174 1175 KASSERT(VOP_ISLOCKED(vp)); 1176 1177 node = VP_TO_TMPFS_NODE(vp); 1178 1179 /* Disallow this operation if the file system is mounted read-only. */ 1180 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1181 return EROFS; 1182 1183 /* Immutable or append-only files cannot be modified, either. */ 1184 if (node->tn_flags & (IMMUTABLE | APPEND)) 1185 return EPERM; 1186 1187 /* XXX: The following comes from UFS code, and can be found in 1188 * several other file systems. Shouldn't this be centralized 1189 * somewhere? */ 1190 if (cred->cr_uid != node->tn_uid && 1191 (error = suser(cred, &l->l_proc->p_acflag)) && 1192 ((vaflags & VA_UTIMES_NULL) == 0 || 1193 (error = VOP_ACCESS(vp, VWRITE, cred, l)))) 1194 return error; 1195 1196 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL) 1197 node->tn_status |= TMPFS_NODE_ACCESSED; 1198 1199 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) 1200 node->tn_status |= TMPFS_NODE_MODIFIED; 1201 1202 tmpfs_update(vp, atime, mtime, 0); 1203 1204 KASSERT(VOP_ISLOCKED(vp)); 1205 1206 return 0; 1207 } 1208 1209 /* --------------------------------------------------------------------- */ 1210 1211 /* Sync timestamps */ 1212 void 1213 tmpfs_itimes(struct vnode *vp, const struct timespec *acc, 1214 const struct timespec *mod) 1215 { 1216 struct tmpfs_node *node; 1217 const struct timespec *ts = NULL; 1218 struct timespec tsb; 1219 1220 node = VP_TO_TMPFS_NODE(vp); 1221 1222 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | 1223 TMPFS_NODE_CHANGED)) == 0) 1224 return; 1225 1226 if (node->tn_status & TMPFS_NODE_ACCESSED) { 1227 if (acc == NULL) 1228 acc = ts == NULL ? (ts = nanotime(&tsb)) : ts; 1229 node->tn_atime = *acc; 1230 } 1231 if (node->tn_status & TMPFS_NODE_MODIFIED) { 1232 if (mod == NULL) 1233 mod = ts == NULL ? (ts = nanotime(&tsb)) : ts; 1234 node->tn_mtime = *mod; 1235 } 1236 if (node->tn_status & TMPFS_NODE_CHANGED) { 1237 if (ts == NULL) 1238 ts = nanotime(&tsb); 1239 node->tn_ctime = *ts; 1240 } 1241 node->tn_status &= 1242 ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); 1243 } 1244 1245 /* --------------------------------------------------------------------- */ 1246 1247 void 1248 tmpfs_update(struct vnode *vp, const struct timespec *acc, 1249 const struct timespec *mod, int flags) 1250 { 1251 1252 struct tmpfs_node *node; 1253 1254 KASSERT(VOP_ISLOCKED(vp)); 1255 1256 node = VP_TO_TMPFS_NODE(vp); 1257 1258 if (flags & UPDATE_CLOSE) 1259 ; /* XXX Need to do anything special? */ 1260 1261 tmpfs_itimes(vp, acc, mod); 1262 1263 KASSERT(VOP_ISLOCKED(vp)); 1264 } 1265 1266 /* --------------------------------------------------------------------- */ 1267 1268 int 1269 tmpfs_truncate(struct vnode *vp, off_t length) 1270 { 1271 boolean_t extended; 1272 int error; 1273 struct tmpfs_node *node; 1274 1275 node = VP_TO_TMPFS_NODE(vp); 1276 extended = length > node->tn_size; 1277 1278 if (length < 0) { 1279 error = EINVAL; 1280 goto out; 1281 } 1282 1283 if (node->tn_size == length) { 1284 error = 0; 1285 goto out; 1286 } 1287 1288 error = tmpfs_reg_resize(vp, length); 1289 if (error == 0) { 1290 VN_KNOTE(vp, NOTE_ATTRIB | (extended ? NOTE_EXTEND : 0)); 1291 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; 1292 } 1293 1294 out: 1295 tmpfs_update(vp, NULL, NULL, 0); 1296 1297 return error; 1298 } 1299