| 1 | /* $NetBSD: tmpfs_subr.c,v 1.101 2015/10/29 16:19:44 leot Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2005-2013 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, and by Mindaugas Rasiukevicius. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms, with or without |
| 12 | * modification, are permitted provided that the following conditions |
| 13 | * are met: |
| 14 | * 1. Redistributions of source code must retain the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer. |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in the |
| 18 | * documentation and/or other materials provided with the distribution. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 22 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 23 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 24 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 27 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 29 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 30 | * POSSIBILITY OF SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | /* |
| 34 | * Efficient memory file system: interfaces for inode and directory entry |
| 35 | * construction, destruction and manipulation. |
| 36 | * |
| 37 | * Reference counting |
| 38 | * |
| 39 | * The link count of inode (tmpfs_node_t::tn_links) is used as a |
| 40 | * reference counter. However, it has slightly different semantics. |
| 41 | * |
| 42 | * For directories - link count represents directory entries, which |
| 43 | * refer to the directories. In other words, it represents the count |
| 44 | * of sub-directories. It also takes into account the virtual '.' |
| 45 | * entry (which has no real entry in the list). For files - link count |
| 46 | * represents the hard links. Since only empty directories can be |
| 47 | * removed - link count aligns the reference counting requirements |
| 48 | * enough. Note: to check whether directory is not empty, the inode |
| 49 | * size (tmpfs_node_t::tn_size) can be used. |
| 50 | * |
| 51 | * The inode itself, as an object, gathers its first reference when |
| 52 | * directory entry is attached via tmpfs_dir_attach(9). For instance, |
| 53 | * after regular tmpfs_create(), a file would have a link count of 1, |
| 54 | * while directory after tmpfs_mkdir() would have 2 (due to '.'). |
| 55 | * |
| 56 | * Reclamation |
| 57 | * |
| 58 | * It should be noted that tmpfs inodes rely on a combination of vnode |
| 59 | * reference counting and link counting. That is, an inode can only be |
| 60 | * destroyed if its associated vnode is inactive. The destruction is |
| 61 | * done on vnode reclamation i.e. tmpfs_reclaim(). It should be noted |
| 62 | * that tmpfs_node_t::tn_links being 0 is a destruction criterion. |
| 63 | * |
| 64 | * If an inode has references within the file system (tn_links > 0) and |
| 65 | * its inactive vnode gets reclaimed/recycled - then the association is |
| 66 | * broken in tmpfs_reclaim(). In such case, an inode will always pass |
| 67 | * tmpfs_lookup() and thus vcache_get() to associate a new vnode. |
| 68 | * |
| 69 | * Lock order |
| 70 | * |
| 71 | * vnode_t::v_vlock -> |
| 72 | * vnode_t::v_interlock |
| 73 | */ |
| 74 | |
| 75 | #include <sys/cdefs.h> |
| 76 | __KERNEL_RCSID(0, "$NetBSD: tmpfs_subr.c,v 1.101 2015/10/29 16:19:44 leot Exp $" ); |
| 77 | |
| 78 | #include <sys/param.h> |
| 79 | #include <sys/cprng.h> |
| 80 | #include <sys/dirent.h> |
| 81 | #include <sys/event.h> |
| 82 | #include <sys/kmem.h> |
| 83 | #include <sys/mount.h> |
| 84 | #include <sys/namei.h> |
| 85 | #include <sys/time.h> |
| 86 | #include <sys/stat.h> |
| 87 | #include <sys/systm.h> |
| 88 | #include <sys/vnode.h> |
| 89 | #include <sys/kauth.h> |
| 90 | #include <sys/atomic.h> |
| 91 | |
| 92 | #include <uvm/uvm.h> |
| 93 | |
| 94 | #include <miscfs/specfs/specdev.h> |
| 95 | #include <miscfs/genfs/genfs.h> |
| 96 | #include <fs/tmpfs/tmpfs.h> |
| 97 | #include <fs/tmpfs/tmpfs_fifoops.h> |
| 98 | #include <fs/tmpfs/tmpfs_specops.h> |
| 99 | #include <fs/tmpfs/tmpfs_vnops.h> |
| 100 | |
| 101 | static void tmpfs_dir_putseq(tmpfs_node_t *, tmpfs_dirent_t *); |
| 102 | |
| 103 | /* |
| 104 | * Initialize vnode with tmpfs node. |
| 105 | */ |
| 106 | static void |
| 107 | tmpfs_init_vnode(struct vnode *vp, tmpfs_node_t *node) |
| 108 | { |
| 109 | kmutex_t *slock; |
| 110 | |
| 111 | KASSERT(node->tn_vnode == NULL); |
| 112 | |
| 113 | /* Share the interlock with the node. */ |
| 114 | if (node->tn_type == VREG) { |
| 115 | slock = node->tn_spec.tn_reg.tn_aobj->vmobjlock; |
| 116 | mutex_obj_hold(slock); |
| 117 | uvm_obj_setlock(&vp->v_uobj, slock); |
| 118 | } |
| 119 | |
| 120 | vp->v_tag = VT_TMPFS; |
| 121 | vp->v_type = node->tn_type; |
| 122 | |
| 123 | /* Type-specific initialization. */ |
| 124 | switch (vp->v_type) { |
| 125 | case VBLK: |
| 126 | case VCHR: |
| 127 | vp->v_op = tmpfs_specop_p; |
| 128 | spec_node_init(vp, node->tn_spec.tn_dev.tn_rdev); |
| 129 | break; |
| 130 | case VFIFO: |
| 131 | vp->v_op = tmpfs_fifoop_p; |
| 132 | break; |
| 133 | case VDIR: |
| 134 | if (node->tn_spec.tn_dir.tn_parent == node) |
| 135 | vp->v_vflag |= VV_ROOT; |
| 136 | /* FALLTHROUGH */ |
| 137 | case VLNK: |
| 138 | case VREG: |
| 139 | case VSOCK: |
| 140 | vp->v_op = tmpfs_vnodeop_p; |
| 141 | break; |
| 142 | default: |
| 143 | panic("bad node type %d" , vp->v_type); |
| 144 | break; |
| 145 | } |
| 146 | |
| 147 | vp->v_data = node; |
| 148 | node->tn_vnode = vp; |
| 149 | uvm_vnp_setsize(vp, node->tn_size); |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | * tmpfs_loadvnode: initialise a vnode for a specified inode. |
| 154 | */ |
| 155 | int |
| 156 | tmpfs_loadvnode(struct mount *mp, struct vnode *vp, |
| 157 | const void *key, size_t key_len, const void **new_key) |
| 158 | { |
| 159 | tmpfs_node_t *node; |
| 160 | |
| 161 | KASSERT(key_len == sizeof(node)); |
| 162 | memcpy(&node, key, key_len); |
| 163 | |
| 164 | if (node->tn_links == 0) |
| 165 | return ENOENT; |
| 166 | |
| 167 | tmpfs_init_vnode(vp, node); |
| 168 | |
| 169 | *new_key = &vp->v_data; |
| 170 | |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * tmpfs_newvnode: allocate a new inode of a specified type and |
| 176 | * attach the vonode. |
| 177 | */ |
| 178 | int |
| 179 | tmpfs_newvnode(struct mount *mp, struct vnode *dvp, struct vnode *vp, |
| 180 | struct vattr *vap, kauth_cred_t cred, |
| 181 | size_t *key_len, const void **new_key) |
| 182 | { |
| 183 | tmpfs_mount_t *tmp = VFS_TO_TMPFS(mp); |
| 184 | tmpfs_node_t *node, *dnode; |
| 185 | |
| 186 | if (dvp != NULL) { |
| 187 | KASSERT(VOP_ISLOCKED(dvp)); |
| 188 | dnode = VP_TO_TMPFS_DIR(dvp); |
| 189 | if (dnode->tn_links == 0) |
| 190 | return ENOENT; |
| 191 | if (vap->va_type == VDIR) { |
| 192 | /* Check for maximum links limit. */ |
| 193 | if (dnode->tn_links == LINK_MAX) |
| 194 | return EMLINK; |
| 195 | KASSERT(dnode->tn_links < LINK_MAX); |
| 196 | } |
| 197 | } else |
| 198 | dnode = NULL; |
| 199 | |
| 200 | node = tmpfs_node_get(tmp); |
| 201 | if (node == NULL) |
| 202 | return ENOSPC; |
| 203 | |
| 204 | /* Initially, no references and no associations. */ |
| 205 | node->tn_links = 0; |
| 206 | node->tn_vnode = NULL; |
| 207 | node->tn_holdcount = 0; |
| 208 | node->tn_dirent_hint = NULL; |
| 209 | |
| 210 | /* |
| 211 | * XXX Where the pool is backed by a map larger than (4GB * |
| 212 | * sizeof(*node)), this may produce duplicate inode numbers |
| 213 | * for applications that do not understand 64-bit ino_t. |
| 214 | */ |
| 215 | node->tn_id = (ino_t)((uintptr_t)node / sizeof(*node)); |
| 216 | /* |
| 217 | * Make sure the generation number is not zero. |
| 218 | * tmpfs_inactive() uses generation zero to mark dead nodes. |
| 219 | */ |
| 220 | do { |
| 221 | node->tn_gen = TMPFS_NODE_GEN_MASK & cprng_fast32(); |
| 222 | } while (node->tn_gen == 0); |
| 223 | |
| 224 | /* Generic initialization. */ |
| 225 | KASSERT((int)vap->va_type != VNOVAL); |
| 226 | node->tn_type = vap->va_type; |
| 227 | node->tn_size = 0; |
| 228 | node->tn_flags = 0; |
| 229 | node->tn_lockf = NULL; |
| 230 | |
| 231 | vfs_timestamp(&node->tn_atime); |
| 232 | node->tn_birthtime = node->tn_atime; |
| 233 | node->tn_ctime = node->tn_atime; |
| 234 | node->tn_mtime = node->tn_atime; |
| 235 | |
| 236 | if (dvp == NULL) { |
| 237 | KASSERT(vap->va_uid != VNOVAL && vap->va_gid != VNOVAL); |
| 238 | node->tn_uid = vap->va_uid; |
| 239 | node->tn_gid = vap->va_gid; |
| 240 | vp->v_vflag |= VV_ROOT; |
| 241 | } else { |
| 242 | KASSERT(dnode != NULL); |
| 243 | node->tn_uid = kauth_cred_geteuid(cred); |
| 244 | node->tn_gid = dnode->tn_gid; |
| 245 | } |
| 246 | KASSERT(vap->va_mode != VNOVAL); |
| 247 | node->tn_mode = vap->va_mode; |
| 248 | |
| 249 | /* Type-specific initialization. */ |
| 250 | switch (node->tn_type) { |
| 251 | case VBLK: |
| 252 | case VCHR: |
| 253 | /* Character/block special device. */ |
| 254 | KASSERT(vap->va_rdev != VNOVAL); |
| 255 | node->tn_spec.tn_dev.tn_rdev = vap->va_rdev; |
| 256 | break; |
| 257 | case VDIR: |
| 258 | /* Directory. */ |
| 259 | TAILQ_INIT(&node->tn_spec.tn_dir.tn_dir); |
| 260 | node->tn_spec.tn_dir.tn_parent = NULL; |
| 261 | node->tn_spec.tn_dir.tn_seq_arena = NULL; |
| 262 | node->tn_spec.tn_dir.tn_next_seq = TMPFS_DIRSEQ_START; |
| 263 | node->tn_spec.tn_dir.tn_readdir_lastp = NULL; |
| 264 | |
| 265 | /* Extra link count for the virtual '.' entry. */ |
| 266 | node->tn_links++; |
| 267 | break; |
| 268 | case VFIFO: |
| 269 | case VSOCK: |
| 270 | break; |
| 271 | case VLNK: |
| 272 | node->tn_size = 0; |
| 273 | node->tn_spec.tn_lnk.tn_link = NULL; |
| 274 | break; |
| 275 | case VREG: |
| 276 | /* Regular file. Create an underlying UVM object. */ |
| 277 | node->tn_spec.tn_reg.tn_aobj = |
| 278 | uao_create(INT32_MAX - PAGE_SIZE, 0); |
| 279 | node->tn_spec.tn_reg.tn_aobj_pages = 0; |
| 280 | break; |
| 281 | default: |
| 282 | panic("bad node type %d" , vp->v_type); |
| 283 | break; |
| 284 | } |
| 285 | |
| 286 | tmpfs_init_vnode(vp, node); |
| 287 | |
| 288 | mutex_enter(&tmp->tm_lock); |
| 289 | LIST_INSERT_HEAD(&tmp->tm_nodes, node, tn_entries); |
| 290 | mutex_exit(&tmp->tm_lock); |
| 291 | |
| 292 | *key_len = sizeof(vp->v_data); |
| 293 | *new_key = &vp->v_data; |
| 294 | |
| 295 | return 0; |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | * tmpfs_free_node: remove the inode from a list in the mount point and |
| 300 | * destroy the inode structures. |
| 301 | */ |
| 302 | void |
| 303 | tmpfs_free_node(tmpfs_mount_t *tmp, tmpfs_node_t *node) |
| 304 | { |
| 305 | size_t objsz; |
| 306 | uint32_t hold; |
| 307 | |
| 308 | mutex_enter(&tmp->tm_lock); |
| 309 | hold = atomic_or_32_nv(&node->tn_holdcount, TMPFS_NODE_RECLAIMED); |
| 310 | /* Defer destruction to last thread holding this node. */ |
| 311 | if (hold != TMPFS_NODE_RECLAIMED) { |
| 312 | mutex_exit(&tmp->tm_lock); |
| 313 | return; |
| 314 | } |
| 315 | LIST_REMOVE(node, tn_entries); |
| 316 | mutex_exit(&tmp->tm_lock); |
| 317 | |
| 318 | switch (node->tn_type) { |
| 319 | case VLNK: |
| 320 | if (node->tn_size > 0) { |
| 321 | tmpfs_strname_free(tmp, node->tn_spec.tn_lnk.tn_link, |
| 322 | node->tn_size); |
| 323 | } |
| 324 | break; |
| 325 | case VREG: |
| 326 | /* |
| 327 | * Calculate the size of inode data, decrease the used-memory |
| 328 | * counter, and destroy the unerlying UVM object (if any). |
| 329 | */ |
| 330 | objsz = PAGE_SIZE * node->tn_spec.tn_reg.tn_aobj_pages; |
| 331 | if (objsz != 0) { |
| 332 | tmpfs_mem_decr(tmp, objsz); |
| 333 | } |
| 334 | if (node->tn_spec.tn_reg.tn_aobj != NULL) { |
| 335 | uao_detach(node->tn_spec.tn_reg.tn_aobj); |
| 336 | } |
| 337 | break; |
| 338 | case VDIR: |
| 339 | KASSERT(node->tn_size == 0); |
| 340 | KASSERT(node->tn_spec.tn_dir.tn_seq_arena == NULL); |
| 341 | KASSERT(TAILQ_EMPTY(&node->tn_spec.tn_dir.tn_dir)); |
| 342 | KASSERT(node->tn_spec.tn_dir.tn_parent == NULL || |
| 343 | node == tmp->tm_root); |
| 344 | break; |
| 345 | default: |
| 346 | break; |
| 347 | } |
| 348 | KASSERT(node->tn_vnode == NULL); |
| 349 | KASSERT(node->tn_links == 0); |
| 350 | |
| 351 | tmpfs_node_put(tmp, node); |
| 352 | } |
| 353 | |
| 354 | /* |
| 355 | * tmpfs_construct_node: allocate a new file of specified type and adds it |
| 356 | * into the parent directory. |
| 357 | * |
| 358 | * => Credentials of the caller are used. |
| 359 | */ |
| 360 | int |
| 361 | tmpfs_construct_node(vnode_t *dvp, vnode_t **vpp, struct vattr *vap, |
| 362 | struct componentname *cnp, char *target) |
| 363 | { |
| 364 | tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount); |
| 365 | tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp), *node; |
| 366 | tmpfs_dirent_t *de, *wde; |
| 367 | char *slink = NULL; |
| 368 | int ssize = 0; |
| 369 | int error; |
| 370 | |
| 371 | /* Allocate symlink target. */ |
| 372 | if (target != NULL) { |
| 373 | KASSERT(vap->va_type == VLNK); |
| 374 | ssize = strlen(target); |
| 375 | KASSERT(ssize < MAXPATHLEN); |
| 376 | if (ssize > 0) { |
| 377 | slink = tmpfs_strname_alloc(tmp, ssize); |
| 378 | if (slink == NULL) |
| 379 | return ENOSPC; |
| 380 | memcpy(slink, target, ssize); |
| 381 | } |
| 382 | } |
| 383 | |
| 384 | /* Allocate a directory entry that points to the new file. */ |
| 385 | error = tmpfs_alloc_dirent(tmp, cnp->cn_nameptr, cnp->cn_namelen, &de); |
| 386 | if (error) { |
| 387 | if (slink != NULL) |
| 388 | tmpfs_strname_free(tmp, slink, ssize); |
| 389 | return error; |
| 390 | } |
| 391 | |
| 392 | /* Allocate a vnode that represents the new file. */ |
| 393 | error = vcache_new(dvp->v_mount, dvp, vap, cnp->cn_cred, vpp); |
| 394 | if (error) { |
| 395 | if (slink != NULL) |
| 396 | tmpfs_strname_free(tmp, slink, ssize); |
| 397 | tmpfs_free_dirent(tmp, de); |
| 398 | return error; |
| 399 | } |
| 400 | error = vn_lock(*vpp, LK_EXCLUSIVE); |
| 401 | if (error) { |
| 402 | vrele(*vpp); |
| 403 | *vpp = NULL; |
| 404 | if (slink != NULL) |
| 405 | tmpfs_strname_free(tmp, slink, ssize); |
| 406 | tmpfs_free_dirent(tmp, de); |
| 407 | return error; |
| 408 | } |
| 409 | |
| 410 | node = VP_TO_TMPFS_NODE(*vpp); |
| 411 | |
| 412 | if (slink != NULL) { |
| 413 | node->tn_spec.tn_lnk.tn_link = slink; |
| 414 | node->tn_size = ssize; |
| 415 | } |
| 416 | |
| 417 | /* Remove whiteout before adding the new entry. */ |
| 418 | if (cnp->cn_flags & ISWHITEOUT) { |
| 419 | wde = tmpfs_dir_lookup(dnode, cnp); |
| 420 | KASSERT(wde != NULL && wde->td_node == TMPFS_NODE_WHITEOUT); |
| 421 | tmpfs_dir_detach(dnode, wde); |
| 422 | tmpfs_free_dirent(tmp, wde); |
| 423 | } |
| 424 | |
| 425 | /* Associate inode and attach the entry into the directory. */ |
| 426 | tmpfs_dir_attach(dnode, de, node); |
| 427 | |
| 428 | /* Make node opaque if requested. */ |
| 429 | if (cnp->cn_flags & ISWHITEOUT) |
| 430 | node->tn_flags |= UF_OPAQUE; |
| 431 | |
| 432 | /* Update the parent's timestamps. */ |
| 433 | tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME); |
| 434 | |
| 435 | VOP_UNLOCK(*vpp); |
| 436 | |
| 437 | return 0; |
| 438 | } |
| 439 | |
| 440 | /* |
| 441 | * tmpfs_alloc_dirent: allocates a new directory entry for the inode. |
| 442 | * The directory entry contains a path name component. |
| 443 | */ |
| 444 | int |
| 445 | tmpfs_alloc_dirent(tmpfs_mount_t *tmp, const char *name, uint16_t len, |
| 446 | tmpfs_dirent_t **de) |
| 447 | { |
| 448 | tmpfs_dirent_t *nde; |
| 449 | |
| 450 | nde = tmpfs_dirent_get(tmp); |
| 451 | if (nde == NULL) |
| 452 | return ENOSPC; |
| 453 | |
| 454 | nde->td_name = tmpfs_strname_alloc(tmp, len); |
| 455 | if (nde->td_name == NULL) { |
| 456 | tmpfs_dirent_put(tmp, nde); |
| 457 | return ENOSPC; |
| 458 | } |
| 459 | nde->td_namelen = len; |
| 460 | memcpy(nde->td_name, name, len); |
| 461 | nde->td_seq = TMPFS_DIRSEQ_NONE; |
| 462 | nde->td_node = NULL; /* for asserts */ |
| 463 | |
| 464 | *de = nde; |
| 465 | return 0; |
| 466 | } |
| 467 | |
| 468 | /* |
| 469 | * tmpfs_free_dirent: free a directory entry. |
| 470 | */ |
| 471 | void |
| 472 | tmpfs_free_dirent(tmpfs_mount_t *tmp, tmpfs_dirent_t *de) |
| 473 | { |
| 474 | KASSERT(de->td_node == NULL); |
| 475 | KASSERT(de->td_seq == TMPFS_DIRSEQ_NONE); |
| 476 | tmpfs_strname_free(tmp, de->td_name, de->td_namelen); |
| 477 | tmpfs_dirent_put(tmp, de); |
| 478 | } |
| 479 | |
| 480 | /* |
| 481 | * tmpfs_dir_attach: associate directory entry with a specified inode, |
| 482 | * and attach the entry into the directory, specified by vnode. |
| 483 | * |
| 484 | * => Increases link count on the associated node. |
| 485 | * => Increases link count on directory node if our node is VDIR. |
| 486 | * => It is caller's responsibility to check for the LINK_MAX limit. |
| 487 | * => Triggers kqueue events here. |
| 488 | */ |
| 489 | void |
| 490 | tmpfs_dir_attach(tmpfs_node_t *dnode, tmpfs_dirent_t *de, tmpfs_node_t *node) |
| 491 | { |
| 492 | vnode_t *dvp = dnode->tn_vnode; |
| 493 | int events = NOTE_WRITE; |
| 494 | |
| 495 | KASSERT(dvp != NULL); |
| 496 | KASSERT(VOP_ISLOCKED(dvp)); |
| 497 | |
| 498 | /* Get a new sequence number. */ |
| 499 | KASSERT(de->td_seq == TMPFS_DIRSEQ_NONE); |
| 500 | de->td_seq = tmpfs_dir_getseq(dnode, de); |
| 501 | |
| 502 | /* Associate directory entry and the inode. */ |
| 503 | de->td_node = node; |
| 504 | if (node != TMPFS_NODE_WHITEOUT) { |
| 505 | KASSERT(node->tn_links < LINK_MAX); |
| 506 | node->tn_links++; |
| 507 | |
| 508 | /* Save the hint (might overwrite). */ |
| 509 | node->tn_dirent_hint = de; |
| 510 | } else if ((dnode->tn_gen & TMPFS_WHITEOUT_BIT) == 0) { |
| 511 | /* Flag that there are whiteout entries. */ |
| 512 | atomic_or_32(&dnode->tn_gen, TMPFS_WHITEOUT_BIT); |
| 513 | } |
| 514 | |
| 515 | /* Insert the entry to the directory (parent of inode). */ |
| 516 | TAILQ_INSERT_TAIL(&dnode->tn_spec.tn_dir.tn_dir, de, td_entries); |
| 517 | dnode->tn_size += sizeof(tmpfs_dirent_t); |
| 518 | uvm_vnp_setsize(dvp, dnode->tn_size); |
| 519 | |
| 520 | if (node != TMPFS_NODE_WHITEOUT && node->tn_type == VDIR) { |
| 521 | /* Set parent. */ |
| 522 | KASSERT(node->tn_spec.tn_dir.tn_parent == NULL); |
| 523 | node->tn_spec.tn_dir.tn_parent = dnode; |
| 524 | |
| 525 | /* Increase the link count of parent. */ |
| 526 | KASSERT(dnode->tn_links < LINK_MAX); |
| 527 | dnode->tn_links++; |
| 528 | events |= NOTE_LINK; |
| 529 | |
| 530 | TMPFS_VALIDATE_DIR(node); |
| 531 | } |
| 532 | VN_KNOTE(dvp, events); |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * tmpfs_dir_detach: disassociate directory entry and its inode, |
| 537 | * and detach the entry from the directory, specified by vnode. |
| 538 | * |
| 539 | * => Decreases link count on the associated node. |
| 540 | * => Decreases the link count on directory node, if our node is VDIR. |
| 541 | * => Triggers kqueue events here. |
| 542 | * |
| 543 | * => Note: dvp and vp may be NULL only if called by tmpfs_unmount(). |
| 544 | */ |
| 545 | void |
| 546 | tmpfs_dir_detach(tmpfs_node_t *dnode, tmpfs_dirent_t *de) |
| 547 | { |
| 548 | tmpfs_node_t *node = de->td_node; |
| 549 | vnode_t *vp, *dvp = dnode->tn_vnode; |
| 550 | int events = NOTE_WRITE; |
| 551 | |
| 552 | KASSERT(dvp == NULL || VOP_ISLOCKED(dvp)); |
| 553 | |
| 554 | if (__predict_true(node != TMPFS_NODE_WHITEOUT)) { |
| 555 | /* Deassociate the inode and entry. */ |
| 556 | node->tn_dirent_hint = NULL; |
| 557 | |
| 558 | KASSERT(node->tn_links > 0); |
| 559 | node->tn_links--; |
| 560 | |
| 561 | if ((vp = node->tn_vnode) != NULL) { |
| 562 | KASSERT(VOP_ISLOCKED(vp)); |
| 563 | VN_KNOTE(vp, node->tn_links ? NOTE_LINK : NOTE_DELETE); |
| 564 | } |
| 565 | |
| 566 | /* If directory - decrease the link count of parent. */ |
| 567 | if (node->tn_type == VDIR) { |
| 568 | KASSERT(node->tn_spec.tn_dir.tn_parent == dnode); |
| 569 | node->tn_spec.tn_dir.tn_parent = NULL; |
| 570 | |
| 571 | KASSERT(dnode->tn_links > 0); |
| 572 | dnode->tn_links--; |
| 573 | events |= NOTE_LINK; |
| 574 | } |
| 575 | } |
| 576 | de->td_node = NULL; |
| 577 | |
| 578 | /* Remove the entry from the directory. */ |
| 579 | if (dnode->tn_spec.tn_dir.tn_readdir_lastp == de) { |
| 580 | dnode->tn_spec.tn_dir.tn_readdir_lastp = NULL; |
| 581 | } |
| 582 | TAILQ_REMOVE(&dnode->tn_spec.tn_dir.tn_dir, de, td_entries); |
| 583 | dnode->tn_size -= sizeof(tmpfs_dirent_t); |
| 584 | tmpfs_dir_putseq(dnode, de); |
| 585 | |
| 586 | if (dvp) { |
| 587 | uvm_vnp_setsize(dvp, dnode->tn_size); |
| 588 | VN_KNOTE(dvp, events); |
| 589 | } |
| 590 | } |
| 591 | |
| 592 | /* |
| 593 | * tmpfs_dir_lookup: find a directory entry in the specified inode. |
| 594 | * |
| 595 | * Note that the . and .. components are not allowed as they do not |
| 596 | * physically exist within directories. |
| 597 | */ |
| 598 | tmpfs_dirent_t * |
| 599 | tmpfs_dir_lookup(tmpfs_node_t *node, struct componentname *cnp) |
| 600 | { |
| 601 | const char *name = cnp->cn_nameptr; |
| 602 | const uint16_t nlen = cnp->cn_namelen; |
| 603 | tmpfs_dirent_t *de; |
| 604 | |
| 605 | KASSERT(VOP_ISLOCKED(node->tn_vnode)); |
| 606 | KASSERT(nlen != 1 || !(name[0] == '.')); |
| 607 | KASSERT(nlen != 2 || !(name[0] == '.' && name[1] == '.')); |
| 608 | TMPFS_VALIDATE_DIR(node); |
| 609 | |
| 610 | TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) { |
| 611 | if (de->td_namelen != nlen) |
| 612 | continue; |
| 613 | if (memcmp(de->td_name, name, nlen) != 0) |
| 614 | continue; |
| 615 | break; |
| 616 | } |
| 617 | return de; |
| 618 | } |
| 619 | |
| 620 | /* |
| 621 | * tmpfs_dir_cached: get a cached directory entry if it is valid. Used to |
| 622 | * avoid unnecessary tmpfs_dir_lookup(). |
| 623 | * |
| 624 | * => The vnode must be locked. |
| 625 | */ |
| 626 | tmpfs_dirent_t * |
| 627 | tmpfs_dir_cached(tmpfs_node_t *node) |
| 628 | { |
| 629 | tmpfs_dirent_t *de = node->tn_dirent_hint; |
| 630 | |
| 631 | KASSERT(VOP_ISLOCKED(node->tn_vnode)); |
| 632 | |
| 633 | if (de == NULL) { |
| 634 | return NULL; |
| 635 | } |
| 636 | KASSERT(de->td_node == node); |
| 637 | |
| 638 | /* |
| 639 | * Directories always have a valid hint. For files, check if there |
| 640 | * are any hard links. If there are - hint might be invalid. |
| 641 | */ |
| 642 | return (node->tn_type != VDIR && node->tn_links > 1) ? NULL : de; |
| 643 | } |
| 644 | |
| 645 | /* |
| 646 | * tmpfs_dir_getseq: get a per-directory sequence number for the entry. |
| 647 | * |
| 648 | * => Shall not be larger than 2^31 for linux32 compatibility. |
| 649 | */ |
| 650 | uint32_t |
| 651 | tmpfs_dir_getseq(tmpfs_node_t *dnode, tmpfs_dirent_t *de) |
| 652 | { |
| 653 | uint32_t seq = de->td_seq; |
| 654 | vmem_t *seq_arena; |
| 655 | vmem_addr_t off; |
| 656 | int error __diagused; |
| 657 | |
| 658 | TMPFS_VALIDATE_DIR(dnode); |
| 659 | |
| 660 | if (__predict_true(seq != TMPFS_DIRSEQ_NONE)) { |
| 661 | /* Already set. */ |
| 662 | KASSERT(seq >= TMPFS_DIRSEQ_START); |
| 663 | return seq; |
| 664 | } |
| 665 | |
| 666 | /* |
| 667 | * The "." and ".." and the end-of-directory have reserved numbers. |
| 668 | * The other sequence numbers are allocated as following: |
| 669 | * |
| 670 | * - The first half of the 2^31 is assigned incrementally. |
| 671 | * |
| 672 | * - If that range is exceeded, then the second half of 2^31 |
| 673 | * is used, but managed by vmem(9). |
| 674 | */ |
| 675 | |
| 676 | seq = dnode->tn_spec.tn_dir.tn_next_seq; |
| 677 | KASSERT(seq >= TMPFS_DIRSEQ_START); |
| 678 | |
| 679 | if (__predict_true(seq < TMPFS_DIRSEQ_END)) { |
| 680 | /* First half: just increment and return. */ |
| 681 | dnode->tn_spec.tn_dir.tn_next_seq++; |
| 682 | return seq; |
| 683 | } |
| 684 | |
| 685 | /* |
| 686 | * First half exceeded, use the second half. May need to create |
| 687 | * vmem(9) arena for the directory first. |
| 688 | */ |
| 689 | if ((seq_arena = dnode->tn_spec.tn_dir.tn_seq_arena) == NULL) { |
| 690 | seq_arena = vmem_create("tmpfscoo" , 0, |
| 691 | TMPFS_DIRSEQ_END - 1, 1, NULL, NULL, NULL, 0, |
| 692 | VM_SLEEP, IPL_NONE); |
| 693 | dnode->tn_spec.tn_dir.tn_seq_arena = seq_arena; |
| 694 | KASSERT(seq_arena != NULL); |
| 695 | } |
| 696 | error = vmem_alloc(seq_arena, 1, VM_SLEEP | VM_BESTFIT, &off); |
| 697 | KASSERT(error == 0); |
| 698 | |
| 699 | KASSERT(off < TMPFS_DIRSEQ_END); |
| 700 | seq = off | TMPFS_DIRSEQ_END; |
| 701 | return seq; |
| 702 | } |
| 703 | |
| 704 | static void |
| 705 | tmpfs_dir_putseq(tmpfs_node_t *dnode, tmpfs_dirent_t *de) |
| 706 | { |
| 707 | vmem_t *seq_arena = dnode->tn_spec.tn_dir.tn_seq_arena; |
| 708 | uint32_t seq = de->td_seq; |
| 709 | |
| 710 | TMPFS_VALIDATE_DIR(dnode); |
| 711 | |
| 712 | if (seq == TMPFS_DIRSEQ_NONE || seq < TMPFS_DIRSEQ_END) { |
| 713 | /* First half (or no sequence number set yet). */ |
| 714 | KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); |
| 715 | } else { |
| 716 | /* Second half. */ |
| 717 | KASSERT(seq_arena != NULL); |
| 718 | KASSERT(seq >= TMPFS_DIRSEQ_END); |
| 719 | seq &= ~TMPFS_DIRSEQ_END; |
| 720 | vmem_free(seq_arena, seq, 1); |
| 721 | } |
| 722 | de->td_seq = TMPFS_DIRSEQ_NONE; |
| 723 | |
| 724 | /* Empty? We can reset. */ |
| 725 | if (seq_arena && dnode->tn_size == 0) { |
| 726 | dnode->tn_spec.tn_dir.tn_seq_arena = NULL; |
| 727 | dnode->tn_spec.tn_dir.tn_next_seq = TMPFS_DIRSEQ_START; |
| 728 | vmem_destroy(seq_arena); |
| 729 | } |
| 730 | } |
| 731 | |
| 732 | /* |
| 733 | * tmpfs_dir_lookupbyseq: lookup a directory entry by the sequence number. |
| 734 | */ |
| 735 | tmpfs_dirent_t * |
| 736 | tmpfs_dir_lookupbyseq(tmpfs_node_t *node, off_t seq) |
| 737 | { |
| 738 | tmpfs_dirent_t *de = node->tn_spec.tn_dir.tn_readdir_lastp; |
| 739 | |
| 740 | TMPFS_VALIDATE_DIR(node); |
| 741 | |
| 742 | /* |
| 743 | * First, check the cache. If does not match - perform a lookup. |
| 744 | */ |
| 745 | if (de && de->td_seq == seq) { |
| 746 | KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); |
| 747 | KASSERT(de->td_seq != TMPFS_DIRSEQ_NONE); |
| 748 | return de; |
| 749 | } |
| 750 | TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) { |
| 751 | KASSERT(de->td_seq >= TMPFS_DIRSEQ_START); |
| 752 | KASSERT(de->td_seq != TMPFS_DIRSEQ_NONE); |
| 753 | if (de->td_seq == seq) |
| 754 | return de; |
| 755 | } |
| 756 | return NULL; |
| 757 | } |
| 758 | |
| 759 | /* |
| 760 | * tmpfs_dir_getdotents: helper function for tmpfs_readdir() to get the |
| 761 | * dot meta entries, that is, "." or "..". Copy it to the UIO space. |
| 762 | */ |
| 763 | static int |
| 764 | tmpfs_dir_getdotents(tmpfs_node_t *node, struct dirent *dp, struct uio *uio) |
| 765 | { |
| 766 | tmpfs_dirent_t *de; |
| 767 | off_t next = 0; |
| 768 | int error; |
| 769 | |
| 770 | switch (uio->uio_offset) { |
| 771 | case TMPFS_DIRSEQ_DOT: |
| 772 | dp->d_fileno = node->tn_id; |
| 773 | strlcpy(dp->d_name, "." , sizeof(dp->d_name)); |
| 774 | next = TMPFS_DIRSEQ_DOTDOT; |
| 775 | break; |
| 776 | case TMPFS_DIRSEQ_DOTDOT: |
| 777 | dp->d_fileno = node->tn_spec.tn_dir.tn_parent->tn_id; |
| 778 | strlcpy(dp->d_name, ".." , sizeof(dp->d_name)); |
| 779 | de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir); |
| 780 | next = de ? tmpfs_dir_getseq(node, de) : TMPFS_DIRSEQ_EOF; |
| 781 | break; |
| 782 | default: |
| 783 | KASSERT(false); |
| 784 | } |
| 785 | dp->d_type = DT_DIR; |
| 786 | dp->d_namlen = strlen(dp->d_name); |
| 787 | dp->d_reclen = _DIRENT_SIZE(dp); |
| 788 | |
| 789 | if (dp->d_reclen > uio->uio_resid) { |
| 790 | return EJUSTRETURN; |
| 791 | } |
| 792 | if ((error = uiomove(dp, dp->d_reclen, uio)) != 0) { |
| 793 | return error; |
| 794 | } |
| 795 | |
| 796 | uio->uio_offset = next; |
| 797 | return error; |
| 798 | } |
| 799 | |
| 800 | /* |
| 801 | * tmpfs_dir_getdents: helper function for tmpfs_readdir. |
| 802 | * |
| 803 | * => Returns as much directory entries as can fit in the uio space. |
| 804 | * => The read starts at uio->uio_offset. |
| 805 | */ |
| 806 | int |
| 807 | tmpfs_dir_getdents(tmpfs_node_t *node, struct uio *uio, off_t *cntp) |
| 808 | { |
| 809 | tmpfs_dirent_t *de; |
| 810 | struct dirent dent; |
| 811 | int error = 0; |
| 812 | |
| 813 | KASSERT(VOP_ISLOCKED(node->tn_vnode)); |
| 814 | TMPFS_VALIDATE_DIR(node); |
| 815 | |
| 816 | /* |
| 817 | * First check for the "." and ".." cases. |
| 818 | * Note: tmpfs_dir_getdotents() will "seek" for us. |
| 819 | */ |
| 820 | memset(&dent, 0, sizeof(dent)); |
| 821 | |
| 822 | if (uio->uio_offset == TMPFS_DIRSEQ_DOT) { |
| 823 | if ((error = tmpfs_dir_getdotents(node, &dent, uio)) != 0) { |
| 824 | goto done; |
| 825 | } |
| 826 | (*cntp)++; |
| 827 | } |
| 828 | if (uio->uio_offset == TMPFS_DIRSEQ_DOTDOT) { |
| 829 | if ((error = tmpfs_dir_getdotents(node, &dent, uio)) != 0) { |
| 830 | goto done; |
| 831 | } |
| 832 | (*cntp)++; |
| 833 | } |
| 834 | |
| 835 | /* Done if we reached the end. */ |
| 836 | if (uio->uio_offset == TMPFS_DIRSEQ_EOF) { |
| 837 | goto done; |
| 838 | } |
| 839 | |
| 840 | /* Locate the directory entry given by the given sequence number. */ |
| 841 | de = tmpfs_dir_lookupbyseq(node, uio->uio_offset); |
| 842 | if (de == NULL) { |
| 843 | error = EINVAL; |
| 844 | goto done; |
| 845 | } |
| 846 | |
| 847 | /* |
| 848 | * Read as many entries as possible; i.e., until we reach the end |
| 849 | * of the directory or we exhaust UIO space. |
| 850 | */ |
| 851 | do { |
| 852 | if (de->td_node == TMPFS_NODE_WHITEOUT) { |
| 853 | dent.d_fileno = 1; |
| 854 | dent.d_type = DT_WHT; |
| 855 | } else { |
| 856 | dent.d_fileno = de->td_node->tn_id; |
| 857 | dent.d_type = vtype2dt(de->td_node->tn_type); |
| 858 | } |
| 859 | dent.d_namlen = de->td_namelen; |
| 860 | KASSERT(de->td_namelen < sizeof(dent.d_name)); |
| 861 | memcpy(dent.d_name, de->td_name, de->td_namelen); |
| 862 | dent.d_name[de->td_namelen] = '\0'; |
| 863 | dent.d_reclen = _DIRENT_SIZE(&dent); |
| 864 | |
| 865 | if (dent.d_reclen > uio->uio_resid) { |
| 866 | /* Exhausted UIO space. */ |
| 867 | error = EJUSTRETURN; |
| 868 | break; |
| 869 | } |
| 870 | |
| 871 | /* Copy out the directory entry and continue. */ |
| 872 | error = uiomove(&dent, dent.d_reclen, uio); |
| 873 | if (error) { |
| 874 | break; |
| 875 | } |
| 876 | (*cntp)++; |
| 877 | de = TAILQ_NEXT(de, td_entries); |
| 878 | |
| 879 | } while (uio->uio_resid > 0 && de); |
| 880 | |
| 881 | /* Cache the last entry or clear and mark EOF. */ |
| 882 | uio->uio_offset = de ? tmpfs_dir_getseq(node, de) : TMPFS_DIRSEQ_EOF; |
| 883 | node->tn_spec.tn_dir.tn_readdir_lastp = de; |
| 884 | done: |
| 885 | tmpfs_update(node->tn_vnode, TMPFS_UPDATE_ATIME); |
| 886 | |
| 887 | if (error == EJUSTRETURN) { |
| 888 | /* Exhausted UIO space - just return. */ |
| 889 | error = 0; |
| 890 | } |
| 891 | KASSERT(error >= 0); |
| 892 | return error; |
| 893 | } |
| 894 | |
| 895 | /* |
| 896 | * tmpfs_reg_resize: resize the underlying UVM object associated with the |
| 897 | * specified regular file. |
| 898 | */ |
| 899 | int |
| 900 | tmpfs_reg_resize(struct vnode *vp, off_t newsize) |
| 901 | { |
| 902 | tmpfs_mount_t *tmp = VFS_TO_TMPFS(vp->v_mount); |
| 903 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 904 | struct uvm_object *uobj = node->tn_spec.tn_reg.tn_aobj; |
| 905 | size_t newpages, oldpages; |
| 906 | off_t oldsize; |
| 907 | |
| 908 | KASSERT(vp->v_type == VREG); |
| 909 | KASSERT(newsize >= 0); |
| 910 | |
| 911 | oldsize = node->tn_size; |
| 912 | oldpages = round_page(oldsize) >> PAGE_SHIFT; |
| 913 | newpages = round_page(newsize) >> PAGE_SHIFT; |
| 914 | KASSERT(oldpages == node->tn_spec.tn_reg.tn_aobj_pages); |
| 915 | |
| 916 | if (newpages > oldpages) { |
| 917 | /* Increase the used-memory counter if getting extra pages. */ |
| 918 | if (!tmpfs_mem_incr(tmp, (newpages - oldpages) << PAGE_SHIFT)) { |
| 919 | return ENOSPC; |
| 920 | } |
| 921 | } else if (newsize < oldsize) { |
| 922 | size_t zerolen; |
| 923 | |
| 924 | zerolen = MIN(round_page(newsize), node->tn_size) - newsize; |
| 925 | ubc_zerorange(uobj, newsize, zerolen, UBC_UNMAP_FLAG(vp)); |
| 926 | } |
| 927 | |
| 928 | node->tn_spec.tn_reg.tn_aobj_pages = newpages; |
| 929 | node->tn_size = newsize; |
| 930 | uvm_vnp_setsize(vp, newsize); |
| 931 | |
| 932 | /* |
| 933 | * Free "backing store". |
| 934 | */ |
| 935 | if (newpages < oldpages) { |
| 936 | KASSERT(uobj->vmobjlock == vp->v_interlock); |
| 937 | |
| 938 | mutex_enter(uobj->vmobjlock); |
| 939 | uao_dropswap_range(uobj, newpages, oldpages); |
| 940 | mutex_exit(uobj->vmobjlock); |
| 941 | |
| 942 | /* Decrease the used-memory counter. */ |
| 943 | tmpfs_mem_decr(tmp, (oldpages - newpages) << PAGE_SHIFT); |
| 944 | } |
| 945 | if (newsize > oldsize) { |
| 946 | VN_KNOTE(vp, NOTE_EXTEND); |
| 947 | } |
| 948 | return 0; |
| 949 | } |
| 950 | |
| 951 | /* |
| 952 | * tmpfs_chflags: change flags of the given vnode. |
| 953 | */ |
| 954 | int |
| 955 | tmpfs_chflags(vnode_t *vp, int flags, kauth_cred_t cred, lwp_t *l) |
| 956 | { |
| 957 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 958 | kauth_action_t action = KAUTH_VNODE_WRITE_FLAGS; |
| 959 | int error; |
| 960 | bool changing_sysflags = false; |
| 961 | |
| 962 | KASSERT(VOP_ISLOCKED(vp)); |
| 963 | |
| 964 | /* Disallow this operation if the file system is mounted read-only. */ |
| 965 | if (vp->v_mount->mnt_flag & MNT_RDONLY) |
| 966 | return EROFS; |
| 967 | |
| 968 | /* |
| 969 | * If the new flags have non-user flags that are different than |
| 970 | * those on the node, we need special permission to change them. |
| 971 | */ |
| 972 | if ((flags & SF_SETTABLE) != (node->tn_flags & SF_SETTABLE)) { |
| 973 | action |= KAUTH_VNODE_WRITE_SYSFLAGS; |
| 974 | changing_sysflags = true; |
| 975 | } |
| 976 | |
| 977 | /* |
| 978 | * Indicate that this node's flags have system attributes in them if |
| 979 | * that's the case. |
| 980 | */ |
| 981 | if (node->tn_flags & (SF_IMMUTABLE | SF_APPEND)) { |
| 982 | action |= KAUTH_VNODE_HAS_SYSFLAGS; |
| 983 | } |
| 984 | |
| 985 | error = kauth_authorize_vnode(cred, action, vp, NULL, |
| 986 | genfs_can_chflags(cred, vp->v_type, node->tn_uid, |
| 987 | changing_sysflags)); |
| 988 | if (error) |
| 989 | return error; |
| 990 | |
| 991 | /* |
| 992 | * Set the flags. If we're not setting non-user flags, be careful not |
| 993 | * to overwrite them. |
| 994 | * |
| 995 | * XXX: Can't we always assign here? if the system flags are different, |
| 996 | * the code above should catch attempts to change them without |
| 997 | * proper permissions, and if we're here it means it's okay to |
| 998 | * change them... |
| 999 | */ |
| 1000 | if (!changing_sysflags) { |
| 1001 | /* Clear all user-settable flags and re-set them. */ |
| 1002 | node->tn_flags &= SF_SETTABLE; |
| 1003 | node->tn_flags |= (flags & UF_SETTABLE); |
| 1004 | } else { |
| 1005 | node->tn_flags = flags; |
| 1006 | } |
| 1007 | tmpfs_update(vp, TMPFS_UPDATE_CTIME); |
| 1008 | VN_KNOTE(vp, NOTE_ATTRIB); |
| 1009 | return 0; |
| 1010 | } |
| 1011 | |
| 1012 | /* |
| 1013 | * tmpfs_chmod: change access mode on the given vnode. |
| 1014 | */ |
| 1015 | int |
| 1016 | tmpfs_chmod(vnode_t *vp, mode_t mode, kauth_cred_t cred, lwp_t *l) |
| 1017 | { |
| 1018 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 1019 | int error; |
| 1020 | |
| 1021 | KASSERT(VOP_ISLOCKED(vp)); |
| 1022 | |
| 1023 | /* Disallow this operation if the file system is mounted read-only. */ |
| 1024 | if (vp->v_mount->mnt_flag & MNT_RDONLY) |
| 1025 | return EROFS; |
| 1026 | |
| 1027 | /* Immutable or append-only files cannot be modified, either. */ |
| 1028 | if (node->tn_flags & (IMMUTABLE | APPEND)) |
| 1029 | return EPERM; |
| 1030 | |
| 1031 | error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_SECURITY, vp, |
| 1032 | NULL, genfs_can_chmod(vp->v_type, cred, node->tn_uid, node->tn_gid, mode)); |
| 1033 | if (error) { |
| 1034 | return error; |
| 1035 | } |
| 1036 | node->tn_mode = (mode & ALLPERMS); |
| 1037 | tmpfs_update(vp, TMPFS_UPDATE_CTIME); |
| 1038 | VN_KNOTE(vp, NOTE_ATTRIB); |
| 1039 | return 0; |
| 1040 | } |
| 1041 | |
| 1042 | /* |
| 1043 | * tmpfs_chown: change ownership of the given vnode. |
| 1044 | * |
| 1045 | * => At least one of uid or gid must be different than VNOVAL. |
| 1046 | * => Attribute is unchanged for VNOVAL case. |
| 1047 | */ |
| 1048 | int |
| 1049 | tmpfs_chown(vnode_t *vp, uid_t uid, gid_t gid, kauth_cred_t cred, lwp_t *l) |
| 1050 | { |
| 1051 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 1052 | int error; |
| 1053 | |
| 1054 | KASSERT(VOP_ISLOCKED(vp)); |
| 1055 | |
| 1056 | /* Assign default values if they are unknown. */ |
| 1057 | KASSERT(uid != VNOVAL || gid != VNOVAL); |
| 1058 | if (uid == VNOVAL) { |
| 1059 | uid = node->tn_uid; |
| 1060 | } |
| 1061 | if (gid == VNOVAL) { |
| 1062 | gid = node->tn_gid; |
| 1063 | } |
| 1064 | |
| 1065 | /* Disallow this operation if the file system is mounted read-only. */ |
| 1066 | if (vp->v_mount->mnt_flag & MNT_RDONLY) |
| 1067 | return EROFS; |
| 1068 | |
| 1069 | /* Immutable or append-only files cannot be modified, either. */ |
| 1070 | if (node->tn_flags & (IMMUTABLE | APPEND)) |
| 1071 | return EPERM; |
| 1072 | |
| 1073 | error = kauth_authorize_vnode(cred, KAUTH_VNODE_CHANGE_OWNERSHIP, vp, |
| 1074 | NULL, genfs_can_chown(cred, node->tn_uid, node->tn_gid, uid, |
| 1075 | gid)); |
| 1076 | if (error) { |
| 1077 | return error; |
| 1078 | } |
| 1079 | node->tn_uid = uid; |
| 1080 | node->tn_gid = gid; |
| 1081 | tmpfs_update(vp, TMPFS_UPDATE_CTIME); |
| 1082 | VN_KNOTE(vp, NOTE_ATTRIB); |
| 1083 | return 0; |
| 1084 | } |
| 1085 | |
| 1086 | /* |
| 1087 | * tmpfs_chsize: change size of the given vnode. |
| 1088 | */ |
| 1089 | int |
| 1090 | tmpfs_chsize(vnode_t *vp, u_quad_t size, kauth_cred_t cred, lwp_t *l) |
| 1091 | { |
| 1092 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 1093 | const off_t length = size; |
| 1094 | int error; |
| 1095 | |
| 1096 | KASSERT(VOP_ISLOCKED(vp)); |
| 1097 | |
| 1098 | /* Decide whether this is a valid operation based on the file type. */ |
| 1099 | switch (vp->v_type) { |
| 1100 | case VDIR: |
| 1101 | return EISDIR; |
| 1102 | case VREG: |
| 1103 | if (vp->v_mount->mnt_flag & MNT_RDONLY) { |
| 1104 | return EROFS; |
| 1105 | } |
| 1106 | break; |
| 1107 | case VBLK: |
| 1108 | case VCHR: |
| 1109 | case VFIFO: |
| 1110 | /* |
| 1111 | * Allow modifications of special files even if in the file |
| 1112 | * system is mounted read-only (we are not modifying the |
| 1113 | * files themselves, but the objects they represent). |
| 1114 | */ |
| 1115 | return 0; |
| 1116 | default: |
| 1117 | return EOPNOTSUPP; |
| 1118 | } |
| 1119 | |
| 1120 | /* Immutable or append-only files cannot be modified, either. */ |
| 1121 | if (node->tn_flags & (IMMUTABLE | APPEND)) { |
| 1122 | return EPERM; |
| 1123 | } |
| 1124 | |
| 1125 | if (length < 0) { |
| 1126 | return EINVAL; |
| 1127 | } |
| 1128 | if (node->tn_size == length) { |
| 1129 | return 0; |
| 1130 | } |
| 1131 | |
| 1132 | /* Note: tmpfs_reg_resize() will raise NOTE_EXTEND and NOTE_ATTRIB. */ |
| 1133 | if ((error = tmpfs_reg_resize(vp, length)) != 0) { |
| 1134 | return error; |
| 1135 | } |
| 1136 | tmpfs_update(vp, TMPFS_UPDATE_CTIME | TMPFS_UPDATE_MTIME); |
| 1137 | return 0; |
| 1138 | } |
| 1139 | |
| 1140 | /* |
| 1141 | * tmpfs_chtimes: change access and modification times for vnode. |
| 1142 | */ |
| 1143 | int |
| 1144 | tmpfs_chtimes(vnode_t *vp, const struct timespec *atime, |
| 1145 | const struct timespec *mtime, const struct timespec *btime, |
| 1146 | int vaflags, kauth_cred_t cred, lwp_t *l) |
| 1147 | { |
| 1148 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 1149 | int error; |
| 1150 | |
| 1151 | KASSERT(VOP_ISLOCKED(vp)); |
| 1152 | |
| 1153 | /* Disallow this operation if the file system is mounted read-only. */ |
| 1154 | if (vp->v_mount->mnt_flag & MNT_RDONLY) |
| 1155 | return EROFS; |
| 1156 | |
| 1157 | /* Immutable or append-only files cannot be modified, either. */ |
| 1158 | if (node->tn_flags & (IMMUTABLE | APPEND)) |
| 1159 | return EPERM; |
| 1160 | |
| 1161 | error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_TIMES, vp, NULL, |
| 1162 | genfs_can_chtimes(vp, vaflags, node->tn_uid, cred)); |
| 1163 | if (error) |
| 1164 | return error; |
| 1165 | |
| 1166 | if (atime->tv_sec != VNOVAL) { |
| 1167 | node->tn_atime = *atime; |
| 1168 | } |
| 1169 | if (mtime->tv_sec != VNOVAL) { |
| 1170 | node->tn_mtime = *mtime; |
| 1171 | } |
| 1172 | if (btime->tv_sec != VNOVAL) { |
| 1173 | node->tn_birthtime = *btime; |
| 1174 | } |
| 1175 | VN_KNOTE(vp, NOTE_ATTRIB); |
| 1176 | return 0; |
| 1177 | } |
| 1178 | |
| 1179 | /* |
| 1180 | * tmpfs_update: update the timestamps as indicated by the flags. |
| 1181 | */ |
| 1182 | void |
| 1183 | tmpfs_update(vnode_t *vp, unsigned tflags) |
| 1184 | { |
| 1185 | tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp); |
| 1186 | struct timespec nowtm; |
| 1187 | |
| 1188 | if (tflags == 0) { |
| 1189 | return; |
| 1190 | } |
| 1191 | vfs_timestamp(&nowtm); |
| 1192 | |
| 1193 | if (tflags & TMPFS_UPDATE_ATIME) { |
| 1194 | node->tn_atime = nowtm; |
| 1195 | } |
| 1196 | if (tflags & TMPFS_UPDATE_MTIME) { |
| 1197 | node->tn_mtime = nowtm; |
| 1198 | } |
| 1199 | if (tflags & TMPFS_UPDATE_CTIME) { |
| 1200 | node->tn_ctime = nowtm; |
| 1201 | } |
| 1202 | } |
| 1203 | |