| 1 | /* $NetBSD: tmpfs_rename.c,v 1.8 2015/07/06 10:24:59 wiz Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2012 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Taylor R Campbell. |
| 9 | * |
| 10 | * Redistribution and use in source and binary forms, with or without |
| 11 | * modification, are permitted provided that the following conditions |
| 12 | * are met: |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in the |
| 17 | * documentation and/or other materials provided with the distribution. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * tmpfs rename |
| 34 | */ |
| 35 | |
| 36 | #include <sys/cdefs.h> |
| 37 | __KERNEL_RCSID(0, "$NetBSD: tmpfs_rename.c,v 1.8 2015/07/06 10:24:59 wiz Exp $" ); |
| 38 | |
| 39 | #include <sys/param.h> |
| 40 | #include <sys/errno.h> |
| 41 | #include <sys/kauth.h> |
| 42 | #include <sys/mount.h> |
| 43 | #include <sys/namei.h> |
| 44 | #include <sys/stat.h> |
| 45 | #include <sys/vnode.h> |
| 46 | #include <sys/vnode_if.h> |
| 47 | |
| 48 | #include <miscfs/genfs/genfs.h> |
| 49 | |
| 50 | #include <fs/tmpfs/tmpfs_vnops.h> |
| 51 | #include <fs/tmpfs/tmpfs.h> |
| 52 | |
| 53 | /* |
| 54 | * Forward declarations |
| 55 | */ |
| 56 | |
| 57 | static int tmpfs_sane_rename(struct vnode *, struct componentname *, |
| 58 | struct vnode *, struct componentname *, |
| 59 | kauth_cred_t, bool); |
| 60 | static bool tmpfs_rmdired_p(struct vnode *); |
| 61 | static int tmpfs_gro_lock_directory(struct mount *, struct vnode *); |
| 62 | |
| 63 | static const struct genfs_rename_ops tmpfs_genfs_rename_ops; |
| 64 | |
| 65 | /* |
| 66 | * tmpfs_sane_rename: The hairiest vop, with the saner API. |
| 67 | * |
| 68 | * Arguments: |
| 69 | * |
| 70 | * . fdvp (from directory vnode), |
| 71 | * . fcnp (from component name), |
| 72 | * . tdvp (to directory vnode), |
| 73 | * . tcnp (to component name), |
| 74 | * . cred (credentials structure), and |
| 75 | * . posixly_correct (flag for behaviour if target & source link same file). |
| 76 | * |
| 77 | * fdvp and tdvp may be the same, and must be referenced and unlocked. |
| 78 | */ |
| 79 | static int |
| 80 | tmpfs_sane_rename( |
| 81 | struct vnode *fdvp, struct componentname *fcnp, |
| 82 | struct vnode *tdvp, struct componentname *tcnp, |
| 83 | kauth_cred_t cred, bool posixly_correct) |
| 84 | { |
| 85 | struct tmpfs_dirent *fdirent, *tdirent; |
| 86 | |
| 87 | return genfs_sane_rename(&tmpfs_genfs_rename_ops, |
| 88 | fdvp, fcnp, &fdirent, tdvp, tcnp, &tdirent, |
| 89 | cred, posixly_correct); |
| 90 | } |
| 91 | |
| 92 | /* |
| 93 | * tmpfs_rename: The hairiest vop, with the insanest API. Defer to |
| 94 | * genfs_insane_rename immediately. |
| 95 | */ |
| 96 | int |
| 97 | tmpfs_rename(void *v) |
| 98 | { |
| 99 | |
| 100 | return genfs_insane_rename(v, &tmpfs_sane_rename); |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * tmpfs_gro_directory_empty_p: Return true if the directory vp is |
| 105 | * empty. dvp is its parent. |
| 106 | * |
| 107 | * vp and dvp must be locked and referenced. |
| 108 | */ |
| 109 | static bool |
| 110 | tmpfs_gro_directory_empty_p(struct mount *mp, kauth_cred_t cred, |
| 111 | struct vnode *vp, struct vnode *dvp) |
| 112 | { |
| 113 | |
| 114 | (void)mp; |
| 115 | (void)cred; |
| 116 | (void)dvp; |
| 117 | KASSERT(mp != NULL); |
| 118 | KASSERT(vp != NULL); |
| 119 | KASSERT(dvp != NULL); |
| 120 | KASSERT(vp != dvp); |
| 121 | KASSERT(vp->v_mount == mp); |
| 122 | KASSERT(dvp->v_mount == mp); |
| 123 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
| 124 | KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE); |
| 125 | |
| 126 | return (VP_TO_TMPFS_NODE(vp)->tn_size == 0); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * tmpfs_gro_rename_check_possible: Check whether a rename is possible |
| 131 | * independent of credentials. |
| 132 | */ |
| 133 | static int |
| 134 | tmpfs_gro_rename_check_possible(struct mount *mp, |
| 135 | struct vnode *fdvp, struct vnode *fvp, |
| 136 | struct vnode *tdvp, struct vnode *tvp) |
| 137 | { |
| 138 | |
| 139 | (void)mp; |
| 140 | KASSERT(mp != NULL); |
| 141 | KASSERT(fdvp != NULL); |
| 142 | KASSERT(fvp != NULL); |
| 143 | KASSERT(tdvp != NULL); |
| 144 | KASSERT(fdvp != fvp); |
| 145 | KASSERT(fdvp != tvp); |
| 146 | KASSERT(tdvp != fvp); |
| 147 | KASSERT(tdvp != tvp); |
| 148 | KASSERT(fvp != tvp); |
| 149 | KASSERT(fdvp->v_type == VDIR); |
| 150 | KASSERT(tdvp->v_type == VDIR); |
| 151 | KASSERT(fdvp->v_mount == mp); |
| 152 | KASSERT(fvp->v_mount == mp); |
| 153 | KASSERT(tdvp->v_mount == mp); |
| 154 | KASSERT((tvp == NULL) || (tvp->v_mount == mp)); |
| 155 | KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE); |
| 156 | KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE); |
| 157 | KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE); |
| 158 | KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE)); |
| 159 | |
| 160 | return genfs_ufslike_rename_check_possible( |
| 161 | VP_TO_TMPFS_NODE(fdvp)->tn_flags, VP_TO_TMPFS_NODE(fvp)->tn_flags, |
| 162 | VP_TO_TMPFS_NODE(tdvp)->tn_flags, |
| 163 | (tvp? VP_TO_TMPFS_NODE(tvp)->tn_flags : 0), (tvp != NULL), |
| 164 | IMMUTABLE, APPEND); |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * tmpfs_gro_rename_check_permitted: Check whether a rename is |
| 169 | * permitted given our credentials. |
| 170 | */ |
| 171 | static int |
| 172 | tmpfs_gro_rename_check_permitted(struct mount *mp, kauth_cred_t cred, |
| 173 | struct vnode *fdvp, struct vnode *fvp, |
| 174 | struct vnode *tdvp, struct vnode *tvp) |
| 175 | { |
| 176 | |
| 177 | (void)mp; |
| 178 | KASSERT(mp != NULL); |
| 179 | KASSERT(fdvp != NULL); |
| 180 | KASSERT(fvp != NULL); |
| 181 | KASSERT(tdvp != NULL); |
| 182 | KASSERT(fdvp != fvp); |
| 183 | KASSERT(fdvp != tvp); |
| 184 | KASSERT(tdvp != fvp); |
| 185 | KASSERT(tdvp != tvp); |
| 186 | KASSERT(fvp != tvp); |
| 187 | KASSERT(fdvp->v_type == VDIR); |
| 188 | KASSERT(tdvp->v_type == VDIR); |
| 189 | KASSERT(fdvp->v_mount == mp); |
| 190 | KASSERT(fvp->v_mount == mp); |
| 191 | KASSERT(tdvp->v_mount == mp); |
| 192 | KASSERT((tvp == NULL) || (tvp->v_mount == mp)); |
| 193 | KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE); |
| 194 | KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE); |
| 195 | KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE); |
| 196 | KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE)); |
| 197 | |
| 198 | return genfs_ufslike_rename_check_permitted(cred, |
| 199 | fdvp, VP_TO_TMPFS_NODE(fdvp)->tn_mode, |
| 200 | VP_TO_TMPFS_NODE(fdvp)->tn_uid, |
| 201 | fvp, VP_TO_TMPFS_NODE(fvp)->tn_uid, |
| 202 | tdvp, VP_TO_TMPFS_NODE(tdvp)->tn_mode, |
| 203 | VP_TO_TMPFS_NODE(tdvp)->tn_uid, |
| 204 | tvp, (tvp? VP_TO_TMPFS_NODE(tvp)->tn_uid : 0)); |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * tmpfs_gro_remove_check_possible: Check whether a remove is possible |
| 209 | * independent of credentials. |
| 210 | */ |
| 211 | static int |
| 212 | tmpfs_gro_remove_check_possible(struct mount *mp, |
| 213 | struct vnode *dvp, struct vnode *vp) |
| 214 | { |
| 215 | |
| 216 | (void)mp; |
| 217 | KASSERT(mp != NULL); |
| 218 | KASSERT(dvp != NULL); |
| 219 | KASSERT(vp != NULL); |
| 220 | KASSERT(dvp != vp); |
| 221 | KASSERT(dvp->v_type == VDIR); |
| 222 | KASSERT(vp->v_type != VDIR); |
| 223 | KASSERT(dvp->v_mount == mp); |
| 224 | KASSERT(vp->v_mount == mp); |
| 225 | KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE); |
| 226 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
| 227 | |
| 228 | return genfs_ufslike_remove_check_possible( |
| 229 | VP_TO_TMPFS_NODE(dvp)->tn_flags, VP_TO_TMPFS_NODE(vp)->tn_flags, |
| 230 | IMMUTABLE, APPEND); |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * tmpfs_gro_remove_check_permitted: Check whether a remove is |
| 235 | * permitted given our credentials. |
| 236 | */ |
| 237 | static int |
| 238 | tmpfs_gro_remove_check_permitted(struct mount *mp, kauth_cred_t cred, |
| 239 | struct vnode *dvp, struct vnode *vp) |
| 240 | { |
| 241 | |
| 242 | (void)mp; |
| 243 | KASSERT(mp != NULL); |
| 244 | KASSERT(dvp != NULL); |
| 245 | KASSERT(vp != NULL); |
| 246 | KASSERT(dvp != vp); |
| 247 | KASSERT(dvp->v_type == VDIR); |
| 248 | KASSERT(vp->v_type != VDIR); |
| 249 | KASSERT(dvp->v_mount == mp); |
| 250 | KASSERT(vp->v_mount == mp); |
| 251 | KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE); |
| 252 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
| 253 | |
| 254 | return genfs_ufslike_remove_check_permitted(cred, |
| 255 | dvp, VP_TO_TMPFS_NODE(dvp)->tn_mode, VP_TO_TMPFS_NODE(dvp)->tn_uid, |
| 256 | vp, VP_TO_TMPFS_NODE(vp)->tn_uid); |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * tmpfs_gro_rename: Actually perform the rename operation. |
| 261 | */ |
| 262 | static int |
| 263 | tmpfs_gro_rename(struct mount *mp, kauth_cred_t cred, |
| 264 | struct vnode *fdvp, struct componentname *fcnp, |
| 265 | void *fde, struct vnode *fvp, |
| 266 | struct vnode *tdvp, struct componentname *tcnp, |
| 267 | void *tde, struct vnode *tvp) |
| 268 | { |
| 269 | tmpfs_node_t *fdnode = VP_TO_TMPFS_DIR(fdvp); |
| 270 | tmpfs_node_t *tdnode = VP_TO_TMPFS_DIR(tdvp); |
| 271 | struct tmpfs_dirent **fdep = fde; |
| 272 | struct tmpfs_dirent **tdep = tde; |
| 273 | char *newname; |
| 274 | |
| 275 | (void)cred; |
| 276 | KASSERT(mp != NULL); |
| 277 | KASSERT(fdvp != NULL); |
| 278 | KASSERT(fcnp != NULL); |
| 279 | KASSERT(fdep != NULL); |
| 280 | KASSERT(fvp != NULL); |
| 281 | KASSERT(tdvp != NULL); |
| 282 | KASSERT(tcnp != NULL); |
| 283 | KASSERT(tdep != NULL); |
| 284 | KASSERT(fdep != tdep); |
| 285 | KASSERT((*fdep) != (*tdep)); |
| 286 | KASSERT((*fdep) != NULL); |
| 287 | KASSERT((*fdep)->td_node == VP_TO_TMPFS_NODE(fvp)); |
| 288 | KASSERT((tvp == NULL) || ((*tdep) != NULL)); |
| 289 | KASSERT((tvp == NULL) || ((*tdep)->td_node == VP_TO_TMPFS_NODE(tvp))); |
| 290 | KASSERT(fdvp != fvp); |
| 291 | KASSERT(fdvp != tvp); |
| 292 | KASSERT(tdvp != fvp); |
| 293 | KASSERT(tdvp != tvp); |
| 294 | KASSERT(fvp != tvp); |
| 295 | KASSERT(fdvp->v_mount == mp); |
| 296 | KASSERT(fvp->v_mount == mp); |
| 297 | KASSERT(tdvp->v_mount == mp); |
| 298 | KASSERT((tvp == NULL) || (tvp->v_mount == mp)); |
| 299 | KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE); |
| 300 | KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE); |
| 301 | KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE); |
| 302 | KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE)); |
| 303 | |
| 304 | if (tmpfs_strname_neqlen(fcnp, tcnp)) { |
| 305 | newname = tmpfs_strname_alloc(VFS_TO_TMPFS(mp), |
| 306 | tcnp->cn_namelen); |
| 307 | if (newname == NULL) |
| 308 | return ENOSPC; |
| 309 | } else { |
| 310 | newname = NULL; |
| 311 | } |
| 312 | |
| 313 | /* |
| 314 | * If we are moving from one directory to another, detach the |
| 315 | * source entry and reattach it to the target directory. |
| 316 | */ |
| 317 | if (fdvp != tdvp) { |
| 318 | tmpfs_dir_detach(fdnode, *fdep); |
| 319 | tmpfs_dir_attach(tdnode, *fdep, VP_TO_TMPFS_NODE(fvp)); |
| 320 | } else if (tvp == NULL) { |
| 321 | /* |
| 322 | * We are changing the directory. tmpfs_dir_attach and |
| 323 | * tmpfs_dir_detach note the events for us, but for |
| 324 | * this case we don't call them, so we must note the |
| 325 | * event explicitly. |
| 326 | */ |
| 327 | VN_KNOTE(fdvp, NOTE_WRITE); |
| 328 | } |
| 329 | |
| 330 | /* |
| 331 | * If we are replacing an existing target entry, delete it. |
| 332 | * |
| 333 | * XXX What if the target is a directory with whiteout entries? |
| 334 | */ |
| 335 | if (tvp != NULL) { |
| 336 | tdnode = VP_TO_TMPFS_DIR(tdvp); |
| 337 | |
| 338 | KASSERT((*tdep) != NULL); |
| 339 | KASSERT((*tdep)->td_node == VP_TO_TMPFS_NODE(tvp)); |
| 340 | KASSERT((fvp->v_type == VDIR) == (tvp->v_type == VDIR)); |
| 341 | if (tvp->v_type == VDIR) { |
| 342 | KASSERT(VP_TO_TMPFS_NODE(tvp)->tn_size == 0); |
| 343 | KASSERT(VP_TO_TMPFS_NODE(tvp)->tn_links == 2); |
| 344 | |
| 345 | /* |
| 346 | * Decrement the extra link count for `.' so |
| 347 | * the vnode will be recycled when released. |
| 348 | */ |
| 349 | VP_TO_TMPFS_NODE(tvp)->tn_links--; |
| 350 | } |
| 351 | tmpfs_dir_detach(tdnode, *tdep); |
| 352 | tmpfs_free_dirent(VFS_TO_TMPFS(mp), *tdep); |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Update the directory entry's name if necessary, and flag |
| 357 | * metadata updates. A memory allocation failure here is not |
| 358 | * OK because we've already committed some changes that we |
| 359 | * can't back out at this point, hence the early allocation |
| 360 | * above. |
| 361 | */ |
| 362 | if (newname != NULL) { |
| 363 | KASSERT(tcnp->cn_namelen <= TMPFS_MAXNAMLEN); |
| 364 | |
| 365 | tmpfs_strname_free(VFS_TO_TMPFS(mp), (*fdep)->td_name, |
| 366 | (*fdep)->td_namelen); |
| 367 | (*fdep)->td_namelen = (uint16_t)tcnp->cn_namelen; |
| 368 | (void)memcpy(newname, tcnp->cn_nameptr, tcnp->cn_namelen); |
| 369 | (*fdep)->td_name = newname; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * Update the timestamps of both parent directories and |
| 374 | * the renamed file itself. |
| 375 | */ |
| 376 | tmpfs_update(fdvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME); |
| 377 | tmpfs_update(tdvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME); |
| 378 | tmpfs_update(fvp, TMPFS_UPDATE_CTIME); |
| 379 | |
| 380 | VN_KNOTE(fvp, NOTE_RENAME); |
| 381 | |
| 382 | genfs_rename_cache_purge(fdvp, fvp, tdvp, tvp); |
| 383 | |
| 384 | return 0; |
| 385 | } |
| 386 | |
| 387 | /* |
| 388 | * tmpfs_gro_remove: Rename an object over another link to itself, |
| 389 | * effectively removing just the original link. |
| 390 | */ |
| 391 | static int |
| 392 | tmpfs_gro_remove(struct mount *mp, kauth_cred_t cred, |
| 393 | struct vnode *dvp, struct componentname *cnp, void *de, struct vnode *vp) |
| 394 | { |
| 395 | tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp); |
| 396 | struct tmpfs_dirent **dep = de; |
| 397 | |
| 398 | (void)vp; |
| 399 | KASSERT(mp != NULL); |
| 400 | KASSERT(dvp != NULL); |
| 401 | KASSERT(cnp != NULL); |
| 402 | KASSERT(dep != NULL); |
| 403 | KASSERT(vp != NULL); |
| 404 | KASSERT(dvp != vp); |
| 405 | KASSERT(dvp->v_mount == mp); |
| 406 | KASSERT(vp->v_mount == mp); |
| 407 | KASSERT(dvp->v_type == VDIR); |
| 408 | KASSERT(vp->v_type != VDIR); |
| 409 | KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE); |
| 410 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
| 411 | |
| 412 | tmpfs_dir_detach(dnode, *dep); |
| 413 | tmpfs_free_dirent(VFS_TO_TMPFS(mp), *dep); |
| 414 | tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME); |
| 415 | |
| 416 | return 0; |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * tmpfs_gro_lookup: Look up and save the lookup results. |
| 421 | */ |
| 422 | static int |
| 423 | tmpfs_gro_lookup(struct mount *mp, struct vnode *dvp, |
| 424 | struct componentname *cnp, void *de_ret, struct vnode **vp_ret) |
| 425 | { |
| 426 | struct tmpfs_dirent *dirent, **dep_ret = de_ret; |
| 427 | struct vnode *vp; |
| 428 | int error __diagused; |
| 429 | |
| 430 | (void)mp; |
| 431 | KASSERT(mp != NULL); |
| 432 | KASSERT(dvp != NULL); |
| 433 | KASSERT(cnp != NULL); |
| 434 | KASSERT(dep_ret != NULL); |
| 435 | KASSERT(vp_ret != NULL); |
| 436 | KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE); |
| 437 | |
| 438 | dirent = tmpfs_dir_lookup(VP_TO_TMPFS_NODE(dvp), cnp); |
| 439 | if (dirent == NULL) |
| 440 | return ENOENT; |
| 441 | |
| 442 | error = vcache_get(mp, &dirent->td_node, sizeof(dirent->td_node), &vp); |
| 443 | if (error) |
| 444 | return error; |
| 445 | KASSERT(vp != NULL); |
| 446 | |
| 447 | /* |
| 448 | * XXX Once namei is fixed, we can change the genfs_rename |
| 449 | * protocol so that we have to lock vp here. |
| 450 | */ |
| 451 | |
| 452 | *dep_ret = dirent; |
| 453 | *vp_ret = vp; |
| 454 | return 0; |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | * tmpfs_rmdired_p: Check whether the directory vp has been rmdired. |
| 459 | * |
| 460 | * vp must be locked and referenced. |
| 461 | */ |
| 462 | static bool |
| 463 | tmpfs_rmdired_p(struct vnode *vp) |
| 464 | { |
| 465 | |
| 466 | KASSERT(vp != NULL); |
| 467 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
| 468 | KASSERT(vp->v_type == VDIR); |
| 469 | |
| 470 | return (VP_TO_TMPFS_NODE(vp)->tn_spec.tn_dir.tn_parent == NULL); |
| 471 | } |
| 472 | |
| 473 | /* |
| 474 | * tmpfs_gro_genealogy: Analyze the genealogy of the source and target |
| 475 | * directories. |
| 476 | */ |
| 477 | static int |
| 478 | tmpfs_gro_genealogy(struct mount *mp, kauth_cred_t cred, |
| 479 | struct vnode *fdvp, struct vnode *tdvp, |
| 480 | struct vnode **intermediate_node_ret) |
| 481 | { |
| 482 | struct vnode *vp, *ovp; |
| 483 | struct tmpfs_node *dnode; |
| 484 | int error; |
| 485 | |
| 486 | (void)cred; |
| 487 | KASSERT(mp != NULL); |
| 488 | KASSERT(fdvp != NULL); |
| 489 | KASSERT(tdvp != NULL); |
| 490 | KASSERT(fdvp != tdvp); |
| 491 | KASSERT(intermediate_node_ret != NULL); |
| 492 | KASSERT(fdvp->v_mount == mp); |
| 493 | KASSERT(tdvp->v_mount == mp); |
| 494 | KASSERT(fdvp->v_type == VDIR); |
| 495 | KASSERT(tdvp->v_type == VDIR); |
| 496 | |
| 497 | /* |
| 498 | * We need to provisionally lock tdvp to keep rmdir from |
| 499 | * deleting it -- or any ancestor -- at an inopportune moment. |
| 500 | */ |
| 501 | error = tmpfs_gro_lock_directory(mp, tdvp); |
| 502 | if (error) |
| 503 | return error; |
| 504 | |
| 505 | vp = tdvp; |
| 506 | vref(vp); |
| 507 | |
| 508 | for (;;) { |
| 509 | KASSERT(vp != NULL); |
| 510 | KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE); |
| 511 | KASSERT(vp->v_mount == mp); |
| 512 | KASSERT(vp->v_type == VDIR); |
| 513 | KASSERT(!tmpfs_rmdired_p(vp)); |
| 514 | |
| 515 | dnode = VP_TO_TMPFS_NODE(vp)->tn_spec.tn_dir.tn_parent; |
| 516 | |
| 517 | /* |
| 518 | * If dnode is null then vp has been rmdir'd, which is |
| 519 | * not supposed to happen because we have it locked. |
| 520 | */ |
| 521 | KASSERT(dnode != NULL); |
| 522 | |
| 523 | /* Did we hit the root without finding fdvp? */ |
| 524 | if (dnode == VP_TO_TMPFS_NODE(vp)) { |
| 525 | vput(vp); |
| 526 | *intermediate_node_ret = NULL; |
| 527 | return 0; |
| 528 | } |
| 529 | |
| 530 | /* Did we find that fdvp is an ancestor of tdvp? */ |
| 531 | if (dnode == VP_TO_TMPFS_NODE(fdvp)) { |
| 532 | KASSERT(dnode->tn_vnode == fdvp); |
| 533 | /* Unlock vp, but keep it referenced. */ |
| 534 | VOP_UNLOCK(vp); |
| 535 | *intermediate_node_ret = vp; |
| 536 | return 0; |
| 537 | } |
| 538 | |
| 539 | /* Neither -- keep ascending the family tree. */ |
| 540 | ovp = vp; |
| 541 | vp = NULL; |
| 542 | error = vcache_get(mp, &dnode, sizeof(dnode), &vp); |
| 543 | vput(ovp); |
| 544 | if (error) |
| 545 | return error; |
| 546 | error = vn_lock(vp, LK_EXCLUSIVE); |
| 547 | if (error) { |
| 548 | vrele(vp); |
| 549 | return error; |
| 550 | } |
| 551 | |
| 552 | /* |
| 553 | * vcache_get only guarantees that dnode will not |
| 554 | * be freed while we get a vnode for it. It does not |
| 555 | * preserve any other invariants, so we must check |
| 556 | * whether the parent has been removed in the meantime. |
| 557 | */ |
| 558 | if (tmpfs_rmdired_p(vp)) { |
| 559 | vput(vp); |
| 560 | return ENOENT; |
| 561 | } |
| 562 | } |
| 563 | } |
| 564 | |
| 565 | /* |
| 566 | * tmpfs_gro_lock_directory: Lock the directory vp, but fail if it has |
| 567 | * been rmdir'd. |
| 568 | */ |
| 569 | static int |
| 570 | tmpfs_gro_lock_directory(struct mount *mp, struct vnode *vp) |
| 571 | { |
| 572 | |
| 573 | (void)mp; |
| 574 | KASSERT(mp != NULL); |
| 575 | KASSERT(vp != NULL); |
| 576 | KASSERT(vp->v_mount == mp); |
| 577 | |
| 578 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
| 579 | |
| 580 | if (tmpfs_rmdired_p(vp)) { |
| 581 | VOP_UNLOCK(vp); |
| 582 | return ENOENT; |
| 583 | } |
| 584 | |
| 585 | return 0; |
| 586 | } |
| 587 | |
| 588 | static const struct genfs_rename_ops tmpfs_genfs_rename_ops = { |
| 589 | .gro_directory_empty_p = tmpfs_gro_directory_empty_p, |
| 590 | .gro_rename_check_possible = tmpfs_gro_rename_check_possible, |
| 591 | .gro_rename_check_permitted = tmpfs_gro_rename_check_permitted, |
| 592 | .gro_remove_check_possible = tmpfs_gro_remove_check_possible, |
| 593 | .gro_remove_check_permitted = tmpfs_gro_remove_check_permitted, |
| 594 | .gro_rename = tmpfs_gro_rename, |
| 595 | .gro_remove = tmpfs_gro_remove, |
| 596 | .gro_lookup = tmpfs_gro_lookup, |
| 597 | .gro_genealogy = tmpfs_gro_genealogy, |
| 598 | .gro_lock_directory = tmpfs_gro_lock_directory, |
| 599 | }; |
| 600 | |