1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1994 Jan-Simon Pendry 5 * Copyright (c) 1994 6 * The Regents of the University of California. All rights reserved. 7 * Copyright (c) 2005, 2006, 2012 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc. 8 * Copyright (c) 2006, 2012 Daichi Goto <daichi@freebsd.org> 9 * 10 * This code is derived from software contributed to Berkeley by 11 * Jan-Simon Pendry. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)union_subr.c 8.20 (Berkeley) 5/20/95 38 * $FreeBSD$ 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/ktr.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/malloc.h> 48 #include <sys/mount.h> 49 #include <sys/namei.h> 50 #include <sys/proc.h> 51 #include <sys/vnode.h> 52 #include <sys/dirent.h> 53 #include <sys/fcntl.h> 54 #include <sys/filedesc.h> 55 #include <sys/stat.h> 56 #include <sys/sysctl.h> 57 #include <sys/taskqueue.h> 58 #include <sys/resourcevar.h> 59 60 #include <machine/atomic.h> 61 62 #include <security/mac/mac_framework.h> 63 64 #include <vm/uma.h> 65 66 #include <fs/unionfs/union.h> 67 68 #define NUNIONFSNODECACHE 16 69 #define UNIONFSHASHMASK (NUNIONFSNODECACHE - 1) 70 71 static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table"); 72 MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part"); 73 MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part"); 74 75 static struct task unionfs_deferred_rele_task; 76 static struct mtx unionfs_deferred_rele_lock; 77 static STAILQ_HEAD(, unionfs_node) unionfs_deferred_rele_list = 78 STAILQ_HEAD_INITIALIZER(unionfs_deferred_rele_list); 79 static TASKQUEUE_DEFINE_THREAD(unionfs_rele); 80 81 unsigned int unionfs_ndeferred = 0; 82 SYSCTL_UINT(_vfs, OID_AUTO, unionfs_ndeferred, CTLFLAG_RD, 83 &unionfs_ndeferred, 0, "unionfs deferred vnode release"); 84 85 static void unionfs_deferred_rele(void *, int); 86 87 /* 88 * Initialize 89 */ 90 int 91 unionfs_init(struct vfsconf *vfsp) 92 { 93 UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */ 94 TASK_INIT(&unionfs_deferred_rele_task, 0, unionfs_deferred_rele, NULL); 95 mtx_init(&unionfs_deferred_rele_lock, "uniondefr", NULL, MTX_DEF); 96 return (0); 97 } 98 99 /* 100 * Uninitialize 101 */ 102 int 103 unionfs_uninit(struct vfsconf *vfsp) 104 { 105 taskqueue_quiesce(taskqueue_unionfs_rele); 106 taskqueue_free(taskqueue_unionfs_rele); 107 mtx_destroy(&unionfs_deferred_rele_lock); 108 return (0); 109 } 110 111 static void 112 unionfs_deferred_rele(void *arg __unused, int pending __unused) 113 { 114 STAILQ_HEAD(, unionfs_node) local_rele_list; 115 struct unionfs_node *unp, *tunp; 116 unsigned int ndeferred; 117 118 ndeferred = 0; 119 STAILQ_INIT(&local_rele_list); 120 mtx_lock(&unionfs_deferred_rele_lock); 121 STAILQ_CONCAT(&local_rele_list, &unionfs_deferred_rele_list); 122 mtx_unlock(&unionfs_deferred_rele_lock); 123 STAILQ_FOREACH_SAFE(unp, &local_rele_list, un_rele, tunp) { 124 ++ndeferred; 125 MPASS(unp->un_dvp != NULL); 126 vrele(unp->un_dvp); 127 free(unp, M_UNIONFSNODE); 128 } 129 130 /* We expect this function to be single-threaded, thus no atomic */ 131 unionfs_ndeferred += ndeferred; 132 } 133 134 static struct unionfs_node_hashhead * 135 unionfs_get_hashhead(struct vnode *dvp, struct vnode *lookup) 136 { 137 struct unionfs_node *unp; 138 139 unp = VTOUNIONFS(dvp); 140 141 return (&(unp->un_hashtbl[vfs_hash_index(lookup) & UNIONFSHASHMASK])); 142 } 143 144 /* 145 * Attempt to lookup a cached unionfs vnode by upper/lower vp 146 * from dvp, with dvp's interlock held. 147 */ 148 static struct vnode * 149 unionfs_get_cached_vnode_locked(struct vnode *lookup, struct vnode *dvp) 150 { 151 struct unionfs_node *unp; 152 struct unionfs_node_hashhead *hd; 153 struct vnode *vp; 154 155 hd = unionfs_get_hashhead(dvp, lookup); 156 157 LIST_FOREACH(unp, hd, un_hash) { 158 if (unp->un_uppervp == lookup || 159 unp->un_lowervp == lookup) { 160 vp = UNIONFSTOV(unp); 161 VI_LOCK_FLAGS(vp, MTX_DUPOK); 162 vp->v_iflag &= ~VI_OWEINACT; 163 if (VN_IS_DOOMED(vp) || 164 ((vp->v_iflag & VI_DOINGINACT) != 0)) { 165 VI_UNLOCK(vp); 166 vp = NULLVP; 167 } else { 168 vrefl(vp); 169 VI_UNLOCK(vp); 170 } 171 return (vp); 172 } 173 } 174 175 return (NULLVP); 176 } 177 178 179 /* 180 * Get the cached vnode. 181 */ 182 static struct vnode * 183 unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp, 184 struct vnode *dvp) 185 { 186 struct vnode *vp; 187 188 vp = NULLVP; 189 VI_LOCK(dvp); 190 if (uvp != NULLVP) 191 vp = unionfs_get_cached_vnode_locked(uvp, dvp); 192 else if (lvp != NULLVP) 193 vp = unionfs_get_cached_vnode_locked(lvp, dvp); 194 VI_UNLOCK(dvp); 195 196 return (vp); 197 } 198 199 /* 200 * Add the new vnode into cache. 201 */ 202 static struct vnode * 203 unionfs_ins_cached_vnode(struct unionfs_node *uncp, 204 struct vnode *dvp) 205 { 206 struct unionfs_node_hashhead *hd; 207 struct vnode *vp; 208 209 ASSERT_VOP_ELOCKED(uncp->un_uppervp, __func__); 210 ASSERT_VOP_ELOCKED(uncp->un_lowervp, __func__); 211 KASSERT(uncp->un_uppervp == NULLVP || uncp->un_uppervp->v_type == VDIR, 212 ("%s: v_type != VDIR", __func__)); 213 KASSERT(uncp->un_lowervp == NULLVP || uncp->un_lowervp->v_type == VDIR, 214 ("%s: v_type != VDIR", __func__)); 215 216 vp = NULLVP; 217 VI_LOCK(dvp); 218 if (uncp->un_uppervp != NULL) 219 vp = unionfs_get_cached_vnode_locked(uncp->un_uppervp, dvp); 220 else if (uncp->un_lowervp != NULL) 221 vp = unionfs_get_cached_vnode_locked(uncp->un_lowervp, dvp); 222 if (vp == NULLVP) { 223 hd = unionfs_get_hashhead(dvp, (uncp->un_uppervp != NULLVP ? 224 uncp->un_uppervp : uncp->un_lowervp)); 225 LIST_INSERT_HEAD(hd, uncp, un_hash); 226 } 227 VI_UNLOCK(dvp); 228 229 return (vp); 230 } 231 232 /* 233 * Remove the vnode. 234 */ 235 static void 236 unionfs_rem_cached_vnode(struct unionfs_node *unp, struct vnode *dvp) 237 { 238 KASSERT(unp != NULL, ("%s: null node", __func__)); 239 KASSERT(dvp != NULLVP, 240 ("%s: null parent vnode", __func__)); 241 242 VI_LOCK(dvp); 243 if (unp->un_hash.le_prev != NULL) { 244 LIST_REMOVE(unp, un_hash); 245 unp->un_hash.le_next = NULL; 246 unp->un_hash.le_prev = NULL; 247 } 248 VI_UNLOCK(dvp); 249 } 250 251 /* 252 * Common cleanup handling for unionfs_nodeget 253 * Upper, lower, and parent directory vnodes are expected to be referenced by 254 * the caller. Upper and lower vnodes, if non-NULL, are also expected to be 255 * exclusively locked by the caller. 256 * This function will return with the caller's locks and references undone. 257 */ 258 static void 259 unionfs_nodeget_cleanup(struct vnode *vp, struct unionfs_node *unp) 260 { 261 262 /* 263 * Lock and reset the default vnode lock; vgone() expects a locked 264 * vnode, and we're going to reset the vnode ops. 265 */ 266 lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); 267 268 /* 269 * Clear out private data and reset the vnode ops to avoid use of 270 * unionfs vnode ops on a partially constructed vnode. 271 */ 272 VI_LOCK(vp); 273 vp->v_data = NULL; 274 vp->v_vnlock = &vp->v_lock; 275 vp->v_op = &dead_vnodeops; 276 VI_UNLOCK(vp); 277 vgone(vp); 278 vput(vp); 279 280 if (unp->un_dvp != NULLVP) 281 vrele(unp->un_dvp); 282 if (unp->un_uppervp != NULLVP) 283 vput(unp->un_uppervp); 284 if (unp->un_lowervp != NULLVP) 285 vput(unp->un_lowervp); 286 if (unp->un_hashtbl != NULL) 287 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, UNIONFSHASHMASK); 288 free(unp->un_path, M_UNIONFSPATH); 289 free(unp, M_UNIONFSNODE); 290 } 291 292 /* 293 * Make a new or get existing unionfs node. 294 * 295 * uppervp and lowervp should be unlocked. Because if new unionfs vnode is 296 * locked, uppervp or lowervp is locked too. In order to prevent dead lock, 297 * you should not lock plurality simultaneously. 298 */ 299 int 300 unionfs_nodeget(struct mount *mp, struct vnode *uppervp, 301 struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, 302 struct componentname *cnp) 303 { 304 char *path; 305 struct unionfs_mount *ump; 306 struct unionfs_node *unp; 307 struct vnode *vp; 308 u_long hashmask; 309 int error; 310 int lkflags; 311 enum vtype vt; 312 313 error = 0; 314 ump = MOUNTTOUNIONFSMOUNT(mp); 315 lkflags = (cnp ? cnp->cn_lkflags : 0); 316 path = (cnp ? cnp->cn_nameptr : NULL); 317 *vpp = NULLVP; 318 319 if (uppervp == NULLVP && lowervp == NULLVP) 320 panic("%s: upper and lower is null", __func__); 321 322 vt = (uppervp != NULLVP ? uppervp->v_type : lowervp->v_type); 323 324 /* If it has no ISLASTCN flag, path check is skipped. */ 325 if (cnp && !(cnp->cn_flags & ISLASTCN)) 326 path = NULL; 327 328 /* check the cache */ 329 if (dvp != NULLVP && vt == VDIR) { 330 vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp); 331 if (vp != NULLVP) { 332 *vpp = vp; 333 goto unionfs_nodeget_out; 334 } 335 } 336 337 unp = malloc(sizeof(struct unionfs_node), 338 M_UNIONFSNODE, M_WAITOK | M_ZERO); 339 340 error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp); 341 if (error != 0) { 342 free(unp, M_UNIONFSNODE); 343 return (error); 344 } 345 if (dvp != NULLVP) 346 vref(dvp); 347 if (uppervp != NULLVP) 348 vref(uppervp); 349 if (lowervp != NULLVP) 350 vref(lowervp); 351 352 if (vt == VDIR) { 353 unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, 354 &hashmask); 355 KASSERT(hashmask == UNIONFSHASHMASK, 356 ("unexpected unionfs hash mask 0x%lx", hashmask)); 357 } 358 359 unp->un_vnode = vp; 360 unp->un_uppervp = uppervp; 361 unp->un_lowervp = lowervp; 362 unp->un_dvp = dvp; 363 if (uppervp != NULLVP) 364 vp->v_vnlock = uppervp->v_vnlock; 365 else 366 vp->v_vnlock = lowervp->v_vnlock; 367 368 if (path != NULL) { 369 unp->un_path = malloc(cnp->cn_namelen + 1, 370 M_UNIONFSPATH, M_WAITOK | M_ZERO); 371 bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen); 372 unp->un_path[cnp->cn_namelen] = '\0'; 373 unp->un_pathlen = cnp->cn_namelen; 374 } 375 vp->v_type = vt; 376 vp->v_data = unp; 377 378 /* 379 * TODO: This is an imperfect check, as there's no guarantee that 380 * the underlying filesystems will always return vnode pointers 381 * for the root inodes that match our cached values. To reduce 382 * the likelihood of failure, for example in the case where either 383 * vnode has been forcibly doomed, we check both pointers and set 384 * VV_ROOT if either matches. 385 */ 386 if (ump->um_uppervp == uppervp || ump->um_lowervp == lowervp) 387 vp->v_vflag |= VV_ROOT; 388 KASSERT(dvp != NULL || (vp->v_vflag & VV_ROOT) != 0, 389 ("%s: NULL dvp for non-root vp %p", __func__, vp)); 390 391 vn_lock_pair(lowervp, false, uppervp, false); 392 error = insmntque1(vp, mp); 393 if (error != 0) { 394 unionfs_nodeget_cleanup(vp, unp); 395 return (error); 396 } 397 if (lowervp != NULL && VN_IS_DOOMED(lowervp)) { 398 vput(lowervp); 399 unp->un_lowervp = NULL; 400 } 401 if (uppervp != NULL && VN_IS_DOOMED(uppervp)) { 402 vput(uppervp); 403 unp->un_uppervp = NULL; 404 } 405 if (unp->un_lowervp == NULL && unp->un_uppervp == NULL) { 406 unionfs_nodeget_cleanup(vp, unp); 407 return (ENOENT); 408 } 409 410 if (dvp != NULLVP && vt == VDIR) 411 *vpp = unionfs_ins_cached_vnode(unp, dvp); 412 if (*vpp != NULLVP) { 413 unionfs_nodeget_cleanup(vp, unp); 414 vp = *vpp; 415 } else { 416 if (uppervp != NULL) 417 VOP_UNLOCK(uppervp); 418 if (lowervp != NULL) 419 VOP_UNLOCK(lowervp); 420 *vpp = vp; 421 } 422 423 unionfs_nodeget_out: 424 if (lkflags & LK_TYPE_MASK) 425 vn_lock(vp, lkflags | LK_RETRY); 426 427 return (0); 428 } 429 430 /* 431 * Clean up the unionfs node. 432 */ 433 void 434 unionfs_noderem(struct vnode *vp) 435 { 436 struct unionfs_node *unp, *unp_t1, *unp_t2; 437 struct unionfs_node_hashhead *hd; 438 struct unionfs_node_status *unsp, *unsp_tmp; 439 struct vnode *lvp; 440 struct vnode *uvp; 441 struct vnode *dvp; 442 int count; 443 int writerefs; 444 445 /* 446 * The root vnode lock may be recursed during unmount, because 447 * it may share the same lock as the unionfs mount's covered vnode, 448 * which is locked across VFS_UNMOUNT(). This lock will then be 449 * recursively taken during the vflush() issued by unionfs_unmount(). 450 * But we still only need to lock the unionfs lock once, because only 451 * one of those lock operations was taken against a unionfs vnode and 452 * will be undone against a unionfs vnode. 453 */ 454 KASSERT(vp->v_vnlock->lk_recurse == 0 || (vp->v_vflag & VV_ROOT) != 0, 455 ("%s: vnode %p locked recursively", __func__, vp)); 456 if (lockmgr(&vp->v_lock, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) 457 panic("%s: failed to acquire lock for vnode lock", __func__); 458 459 /* 460 * Use the interlock to protect the clearing of v_data to 461 * prevent faults in unionfs_lock(). 462 */ 463 VI_LOCK(vp); 464 unp = VTOUNIONFS(vp); 465 lvp = unp->un_lowervp; 466 uvp = unp->un_uppervp; 467 dvp = unp->un_dvp; 468 unp->un_lowervp = unp->un_uppervp = NULLVP; 469 vp->v_vnlock = &(vp->v_lock); 470 vp->v_data = NULL; 471 vp->v_object = NULL; 472 if (unp->un_hashtbl != NULL) { 473 /* 474 * Clear out any cached child vnodes. This should only 475 * be necessary during forced unmount, when the vnode may 476 * be reclaimed with a non-zero use count. Otherwise the 477 * reference held by each child should prevent reclamation. 478 */ 479 for (count = 0; count <= UNIONFSHASHMASK; count++) { 480 hd = unp->un_hashtbl + count; 481 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { 482 LIST_REMOVE(unp_t1, un_hash); 483 unp_t1->un_hash.le_next = NULL; 484 unp_t1->un_hash.le_prev = NULL; 485 } 486 } 487 } 488 VI_UNLOCK(vp); 489 490 writerefs = atomic_load_int(&vp->v_writecount); 491 VNASSERT(writerefs >= 0, vp, 492 ("%s: write count %d, unexpected text ref", __func__, writerefs)); 493 /* 494 * If we were opened for write, we leased the write reference 495 * to the lower vnode. If this is a reclamation due to the 496 * forced unmount, undo the reference now. 497 */ 498 if (writerefs > 0) { 499 VNASSERT(uvp != NULL, vp, 500 ("%s: write reference without upper vnode", __func__)); 501 VOP_ADD_WRITECOUNT(uvp, -writerefs); 502 } 503 if (lvp != NULLVP) 504 VOP_UNLOCK(lvp); 505 if (uvp != NULLVP) 506 VOP_UNLOCK(uvp); 507 508 if (dvp != NULLVP) 509 unionfs_rem_cached_vnode(unp, dvp); 510 511 if (lvp != NULLVP) 512 vrele(lvp); 513 if (uvp != NULLVP) 514 vrele(uvp); 515 if (unp->un_path != NULL) { 516 free(unp->un_path, M_UNIONFSPATH); 517 unp->un_path = NULL; 518 unp->un_pathlen = 0; 519 } 520 521 if (unp->un_hashtbl != NULL) { 522 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, UNIONFSHASHMASK); 523 } 524 525 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { 526 LIST_REMOVE(unsp, uns_list); 527 free(unsp, M_TEMP); 528 } 529 if (dvp != NULLVP) { 530 mtx_lock(&unionfs_deferred_rele_lock); 531 STAILQ_INSERT_TAIL(&unionfs_deferred_rele_list, unp, un_rele); 532 mtx_unlock(&unionfs_deferred_rele_lock); 533 taskqueue_enqueue(taskqueue_unionfs_rele, 534 &unionfs_deferred_rele_task); 535 } else 536 free(unp, M_UNIONFSNODE); 537 } 538 539 /* 540 * Get the unionfs node status object for the vnode corresponding to unp, 541 * for the process that owns td. Allocate a new status object if one 542 * does not already exist. 543 */ 544 void 545 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, 546 struct unionfs_node_status **unspp) 547 { 548 struct unionfs_node_status *unsp; 549 pid_t pid; 550 551 pid = td->td_proc->p_pid; 552 553 KASSERT(NULL != unspp, ("%s: NULL status", __func__)); 554 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), __func__); 555 556 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { 557 if (unsp->uns_pid == pid) { 558 *unspp = unsp; 559 return; 560 } 561 } 562 563 /* create a new unionfs node status */ 564 unsp = malloc(sizeof(struct unionfs_node_status), 565 M_TEMP, M_WAITOK | M_ZERO); 566 567 unsp->uns_pid = pid; 568 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); 569 570 *unspp = unsp; 571 } 572 573 /* 574 * Remove the unionfs node status, if you can. 575 * You need exclusive lock this vnode. 576 */ 577 void 578 unionfs_tryrem_node_status(struct unionfs_node *unp, 579 struct unionfs_node_status *unsp) 580 { 581 KASSERT(NULL != unsp, ("%s: NULL status", __func__)); 582 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), __func__); 583 584 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) 585 return; 586 587 LIST_REMOVE(unsp, uns_list); 588 free(unsp, M_TEMP); 589 } 590 591 /* 592 * Create upper node attr. 593 */ 594 void 595 unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, 596 struct vattr *uva, struct thread *td) 597 { 598 VATTR_NULL(uva); 599 uva->va_type = lva->va_type; 600 uva->va_atime = lva->va_atime; 601 uva->va_mtime = lva->va_mtime; 602 uva->va_ctime = lva->va_ctime; 603 604 switch (ump->um_copymode) { 605 case UNIONFS_TRANSPARENT: 606 uva->va_mode = lva->va_mode; 607 uva->va_uid = lva->va_uid; 608 uva->va_gid = lva->va_gid; 609 break; 610 case UNIONFS_MASQUERADE: 611 if (ump->um_uid == lva->va_uid) { 612 uva->va_mode = lva->va_mode & 077077; 613 uva->va_mode |= (lva->va_type == VDIR ? 614 ump->um_udir : ump->um_ufile) & 0700; 615 uva->va_uid = lva->va_uid; 616 uva->va_gid = lva->va_gid; 617 } else { 618 uva->va_mode = (lva->va_type == VDIR ? 619 ump->um_udir : ump->um_ufile); 620 uva->va_uid = ump->um_uid; 621 uva->va_gid = ump->um_gid; 622 } 623 break; 624 default: /* UNIONFS_TRADITIONAL */ 625 uva->va_mode = 0777 & ~td->td_proc->p_pd->pd_cmask; 626 uva->va_uid = ump->um_uid; 627 uva->va_gid = ump->um_gid; 628 break; 629 } 630 } 631 632 /* 633 * Create upper node attr. 634 */ 635 int 636 unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, 637 struct vattr *uva, struct ucred *cred, struct thread *td) 638 { 639 struct vattr lva; 640 int error; 641 642 if ((error = VOP_GETATTR(lvp, &lva, cred))) 643 return (error); 644 645 unionfs_create_uppervattr_core(ump, &lva, uva, td); 646 647 return (error); 648 } 649 650 /* 651 * relookup 652 * 653 * dvp should be locked on entry and will be locked on return. 654 * 655 * If an error is returned, *vpp will be invalid, otherwise it will hold a 656 * locked, referenced vnode. If *vpp == dvp then remember that only one 657 * LK_EXCLUSIVE lock is held. 658 */ 659 int 660 unionfs_relookup(struct vnode *dvp, struct vnode **vpp, 661 struct componentname *cnp, struct componentname *cn, struct thread *td, 662 char *path, int pathlen, u_long nameiop) 663 { 664 int error; 665 666 cn->cn_namelen = pathlen; 667 cn->cn_pnbuf = path; 668 cn->cn_nameiop = nameiop; 669 cn->cn_flags = (LOCKPARENT | LOCKLEAF | ISLASTCN); 670 cn->cn_lkflags = LK_EXCLUSIVE; 671 cn->cn_cred = cnp->cn_cred; 672 cn->cn_nameptr = cn->cn_pnbuf; 673 674 if (nameiop == DELETE) 675 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); 676 else if (RENAME == nameiop) 677 cn->cn_flags |= (cnp->cn_flags & SAVESTART); 678 else if (nameiop == CREATE) 679 cn->cn_flags |= NOCACHE; 680 681 vref(dvp); 682 VOP_UNLOCK(dvp); 683 684 if ((error = vfs_relookup(dvp, vpp, cn))) { 685 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 686 } else 687 vrele(dvp); 688 689 KASSERT(cn->cn_pnbuf == path, ("%s: cn_pnbuf changed", __func__)); 690 691 return (error); 692 } 693 694 /* 695 * relookup for CREATE namei operation. 696 * 697 * dvp is unionfs vnode. dvp should be locked. 698 * 699 * If it called 'unionfs_copyfile' function by unionfs_link etc, 700 * VOP_LOOKUP information is broken. 701 * So it need relookup in order to create link etc. 702 */ 703 int 704 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 705 struct thread *td) 706 { 707 struct vnode *udvp; 708 struct vnode *vp; 709 struct componentname cn; 710 int error; 711 712 udvp = UNIONFSVPTOUPPERVP(dvp); 713 vp = NULLVP; 714 715 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 716 cnp->cn_namelen, CREATE); 717 if (error) 718 return (error); 719 720 if (vp != NULLVP) { 721 if (udvp == vp) 722 vrele(vp); 723 else 724 vput(vp); 725 726 error = EEXIST; 727 } 728 729 return (error); 730 } 731 732 /* 733 * relookup for DELETE namei operation. 734 * 735 * dvp is unionfs vnode. dvp should be locked. 736 */ 737 int 738 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 739 struct thread *td) 740 { 741 struct vnode *udvp; 742 struct vnode *vp; 743 struct componentname cn; 744 int error; 745 746 udvp = UNIONFSVPTOUPPERVP(dvp); 747 vp = NULLVP; 748 749 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 750 cnp->cn_namelen, DELETE); 751 if (error) 752 return (error); 753 754 if (vp == NULLVP) 755 error = ENOENT; 756 else { 757 if (udvp == vp) 758 vrele(vp); 759 else 760 vput(vp); 761 } 762 763 return (error); 764 } 765 766 /* 767 * relookup for RENAME namei operation. 768 * 769 * dvp is unionfs vnode. dvp should be locked. 770 */ 771 int 772 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 773 struct thread *td) 774 { 775 struct vnode *udvp; 776 struct vnode *vp; 777 struct componentname cn; 778 int error; 779 780 udvp = UNIONFSVPTOUPPERVP(dvp); 781 vp = NULLVP; 782 783 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 784 cnp->cn_namelen, RENAME); 785 if (error) 786 return (error); 787 788 if (vp != NULLVP) { 789 if (udvp == vp) 790 vrele(vp); 791 else 792 vput(vp); 793 } 794 795 return (error); 796 } 797 798 /* 799 * Update the unionfs_node. 800 * 801 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 802 * uvp's lock and lower's lock will be unlocked. 803 */ 804 static void 805 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 806 struct thread *td) 807 { 808 struct unionfs_node_hashhead *hd; 809 struct vnode *vp; 810 struct vnode *lvp; 811 struct vnode *dvp; 812 unsigned count, lockrec; 813 814 vp = UNIONFSTOV(unp); 815 lvp = unp->un_lowervp; 816 ASSERT_VOP_ELOCKED(lvp, __func__); 817 ASSERT_VOP_ELOCKED(uvp, __func__); 818 dvp = unp->un_dvp; 819 820 VNASSERT(vp->v_writecount == 0, vp, 821 ("%s: non-zero writecount", __func__)); 822 /* 823 * Update the upper vnode's lock state to match the lower vnode, 824 * and then switch the unionfs vnode's lock to the upper vnode. 825 */ 826 lockrec = lvp->v_vnlock->lk_recurse; 827 for (count = 0; count < lockrec; count++) 828 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 829 VI_LOCK(vp); 830 unp->un_uppervp = uvp; 831 vp->v_vnlock = uvp->v_vnlock; 832 VI_UNLOCK(vp); 833 834 /* 835 * Re-cache the unionfs vnode against the upper vnode 836 */ 837 if (dvp != NULLVP && vp->v_type == VDIR) { 838 VI_LOCK(dvp); 839 if (unp->un_hash.le_prev != NULL) { 840 LIST_REMOVE(unp, un_hash); 841 hd = unionfs_get_hashhead(dvp, uvp); 842 LIST_INSERT_HEAD(hd, unp, un_hash); 843 } 844 VI_UNLOCK(unp->un_dvp); 845 } 846 } 847 848 /* 849 * Create a new shadow dir. 850 * 851 * udvp should be locked on entry and will be locked on return. 852 * 853 * If no error returned, unp will be updated. 854 */ 855 int 856 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 857 struct unionfs_node *unp, struct componentname *cnp, struct thread *td) 858 { 859 struct vnode *lvp; 860 struct vnode *uvp; 861 struct vattr va; 862 struct vattr lva; 863 struct nameidata nd; 864 struct mount *mp; 865 struct ucred *cred; 866 struct ucred *credbk; 867 struct uidinfo *rootinfo; 868 int error; 869 870 if (unp->un_uppervp != NULLVP) 871 return (EEXIST); 872 873 lvp = unp->un_lowervp; 874 uvp = NULLVP; 875 credbk = cnp->cn_cred; 876 877 /* Authority change to root */ 878 rootinfo = uifind((uid_t)0); 879 cred = crdup(cnp->cn_cred); 880 /* 881 * The calls to chgproccnt() are needed to compensate for change_ruid() 882 * calling chgproccnt(). 883 */ 884 chgproccnt(cred->cr_ruidinfo, 1, 0); 885 change_euid(cred, rootinfo); 886 change_ruid(cred, rootinfo); 887 change_svuid(cred, (uid_t)0); 888 uifree(rootinfo); 889 cnp->cn_cred = cred; 890 891 memset(&nd.ni_cnd, 0, sizeof(struct componentname)); 892 NDPREINIT(&nd); 893 894 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 895 goto unionfs_mkshadowdir_abort; 896 897 if ((error = unionfs_relookup(udvp, &uvp, cnp, &nd.ni_cnd, td, 898 cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 899 goto unionfs_mkshadowdir_abort; 900 if (uvp != NULLVP) { 901 if (udvp == uvp) 902 vrele(uvp); 903 else 904 vput(uvp); 905 906 error = EEXIST; 907 goto unionfs_mkshadowdir_abort; 908 } 909 910 if ((error = vn_start_write(udvp, &mp, V_WAIT | V_PCATCH))) 911 goto unionfs_mkshadowdir_abort; 912 unionfs_create_uppervattr_core(ump, &lva, &va, td); 913 914 error = VOP_MKDIR(udvp, &uvp, &nd.ni_cnd, &va); 915 916 if (!error) { 917 unionfs_node_update(unp, uvp, td); 918 919 /* 920 * XXX The bug which cannot set uid/gid was corrected. 921 * Ignore errors. 922 */ 923 va.va_type = VNON; 924 VOP_SETATTR(uvp, &va, nd.ni_cnd.cn_cred); 925 } 926 vn_finished_write(mp); 927 928 unionfs_mkshadowdir_abort: 929 cnp->cn_cred = credbk; 930 chgproccnt(cred->cr_ruidinfo, -1, 0); 931 crfree(cred); 932 933 return (error); 934 } 935 936 /* 937 * Create a new whiteout. 938 * 939 * dvp should be locked on entry and will be locked on return. 940 */ 941 int 942 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 943 struct thread *td, char *path, int pathlen) 944 { 945 struct vnode *wvp; 946 struct nameidata nd; 947 struct mount *mp; 948 int error; 949 950 wvp = NULLVP; 951 NDPREINIT(&nd); 952 if ((error = unionfs_relookup(dvp, &wvp, cnp, &nd.ni_cnd, td, path, 953 pathlen, CREATE))) { 954 return (error); 955 } 956 if (wvp != NULLVP) { 957 if (dvp == wvp) 958 vrele(wvp); 959 else 960 vput(wvp); 961 962 return (EEXIST); 963 } 964 965 if ((error = vn_start_write(dvp, &mp, V_WAIT | V_PCATCH))) 966 goto unionfs_mkwhiteout_free_out; 967 error = VOP_WHITEOUT(dvp, &nd.ni_cnd, CREATE); 968 969 vn_finished_write(mp); 970 971 unionfs_mkwhiteout_free_out: 972 return (error); 973 } 974 975 /* 976 * Create a new vnode for create a new shadow file. 977 * 978 * If an error is returned, *vpp will be invalid, otherwise it will hold a 979 * locked, referenced and opened vnode. 980 * 981 * unp is never updated. 982 */ 983 static int 984 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 985 struct unionfs_node *unp, struct vattr *uvap, struct thread *td) 986 { 987 struct unionfs_mount *ump; 988 struct vnode *vp; 989 struct vnode *lvp; 990 struct ucred *cred; 991 struct vattr lva; 992 struct nameidata nd; 993 int fmode; 994 int error; 995 996 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 997 vp = NULLVP; 998 lvp = unp->un_lowervp; 999 cred = td->td_ucred; 1000 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 1001 error = 0; 1002 1003 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 1004 return (error); 1005 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 1006 1007 if (unp->un_path == NULL) 1008 panic("%s: NULL un_path", __func__); 1009 1010 nd.ni_cnd.cn_namelen = unp->un_pathlen; 1011 nd.ni_cnd.cn_pnbuf = unp->un_path; 1012 nd.ni_cnd.cn_nameiop = CREATE; 1013 nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF | ISLASTCN; 1014 nd.ni_cnd.cn_lkflags = LK_EXCLUSIVE; 1015 nd.ni_cnd.cn_cred = cred; 1016 nd.ni_cnd.cn_nameptr = nd.ni_cnd.cn_pnbuf; 1017 NDPREINIT(&nd); 1018 1019 vref(udvp); 1020 if ((error = vfs_relookup(udvp, &vp, &nd.ni_cnd)) != 0) 1021 goto unionfs_vn_create_on_upper_free_out2; 1022 vrele(udvp); 1023 1024 if (vp != NULLVP) { 1025 if (vp == udvp) 1026 vrele(vp); 1027 else 1028 vput(vp); 1029 error = EEXIST; 1030 goto unionfs_vn_create_on_upper_free_out1; 1031 } 1032 1033 if ((error = VOP_CREATE(udvp, &vp, &nd.ni_cnd, uvap)) != 0) 1034 goto unionfs_vn_create_on_upper_free_out1; 1035 1036 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { 1037 vput(vp); 1038 goto unionfs_vn_create_on_upper_free_out1; 1039 } 1040 error = VOP_ADD_WRITECOUNT(vp, 1); 1041 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", 1042 __func__, vp, vp->v_writecount); 1043 if (error == 0) { 1044 *vpp = vp; 1045 } else { 1046 VOP_CLOSE(vp, fmode, cred, td); 1047 } 1048 1049 unionfs_vn_create_on_upper_free_out1: 1050 VOP_UNLOCK(udvp); 1051 1052 unionfs_vn_create_on_upper_free_out2: 1053 KASSERT(nd.ni_cnd.cn_pnbuf == unp->un_path, 1054 ("%s: cn_pnbuf changed", __func__)); 1055 1056 return (error); 1057 } 1058 1059 /* 1060 * Copy from lvp to uvp. 1061 * 1062 * lvp and uvp should be locked and opened on entry and will be locked and 1063 * opened on return. 1064 */ 1065 static int 1066 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, 1067 struct ucred *cred, struct thread *td) 1068 { 1069 char *buf; 1070 struct uio uio; 1071 struct iovec iov; 1072 off_t offset; 1073 int count; 1074 int error; 1075 int bufoffset; 1076 1077 error = 0; 1078 memset(&uio, 0, sizeof(uio)); 1079 1080 uio.uio_td = td; 1081 uio.uio_segflg = UIO_SYSSPACE; 1082 uio.uio_offset = 0; 1083 1084 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); 1085 1086 while (error == 0) { 1087 offset = uio.uio_offset; 1088 1089 uio.uio_iov = &iov; 1090 uio.uio_iovcnt = 1; 1091 iov.iov_base = buf; 1092 iov.iov_len = MAXBSIZE; 1093 uio.uio_resid = iov.iov_len; 1094 uio.uio_rw = UIO_READ; 1095 1096 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) 1097 break; 1098 if ((count = MAXBSIZE - uio.uio_resid) == 0) 1099 break; 1100 1101 bufoffset = 0; 1102 while (bufoffset < count) { 1103 uio.uio_iov = &iov; 1104 uio.uio_iovcnt = 1; 1105 iov.iov_base = buf + bufoffset; 1106 iov.iov_len = count - bufoffset; 1107 uio.uio_offset = offset + bufoffset; 1108 uio.uio_resid = iov.iov_len; 1109 uio.uio_rw = UIO_WRITE; 1110 1111 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) 1112 break; 1113 1114 bufoffset += (count - bufoffset) - uio.uio_resid; 1115 } 1116 1117 uio.uio_offset = offset + bufoffset; 1118 } 1119 1120 free(buf, M_TEMP); 1121 1122 return (error); 1123 } 1124 1125 /* 1126 * Copy file from lower to upper. 1127 * 1128 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to 1129 * docopy. 1130 * 1131 * If no error returned, unp will be updated. 1132 */ 1133 int 1134 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, 1135 struct thread *td) 1136 { 1137 struct mount *mp; 1138 struct vnode *udvp; 1139 struct vnode *lvp; 1140 struct vnode *uvp; 1141 struct vattr uva; 1142 int error; 1143 1144 lvp = unp->un_lowervp; 1145 uvp = NULLVP; 1146 1147 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) 1148 return (EROFS); 1149 if (unp->un_dvp == NULLVP) 1150 return (EINVAL); 1151 if (unp->un_uppervp != NULLVP) 1152 return (EEXIST); 1153 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; 1154 if (udvp == NULLVP) 1155 return (EROFS); 1156 if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) 1157 return (EROFS); 1158 1159 error = VOP_ACCESS(lvp, VREAD, cred, td); 1160 if (error != 0) 1161 return (error); 1162 1163 if ((error = vn_start_write(udvp, &mp, V_WAIT | V_PCATCH)) != 0) 1164 return (error); 1165 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); 1166 if (error != 0) { 1167 vn_finished_write(mp); 1168 return (error); 1169 } 1170 1171 if (docopy != 0) { 1172 error = VOP_OPEN(lvp, FREAD, cred, td, NULL); 1173 if (error == 0) { 1174 error = unionfs_copyfile_core(lvp, uvp, cred, td); 1175 VOP_CLOSE(lvp, FREAD, cred, td); 1176 } 1177 } 1178 VOP_CLOSE(uvp, FWRITE, cred, td); 1179 VOP_ADD_WRITECOUNT_CHECKED(uvp, -1); 1180 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", 1181 __func__, uvp, uvp->v_writecount); 1182 1183 vn_finished_write(mp); 1184 1185 if (error == 0) { 1186 /* Reset the attributes. Ignore errors. */ 1187 uva.va_type = VNON; 1188 VOP_SETATTR(uvp, &uva, cred); 1189 } 1190 1191 unionfs_node_update(unp, uvp, td); 1192 1193 return (error); 1194 } 1195 1196 /* 1197 * It checks whether vp can rmdir. (check empty) 1198 * 1199 * vp is unionfs vnode. 1200 * vp should be locked. 1201 */ 1202 int 1203 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) 1204 { 1205 struct vnode *uvp; 1206 struct vnode *lvp; 1207 struct vnode *tvp; 1208 struct dirent *dp; 1209 struct dirent *edp; 1210 struct componentname cn; 1211 struct iovec iov; 1212 struct uio uio; 1213 struct vattr va; 1214 int error; 1215 int eofflag; 1216 int lookuperr; 1217 1218 /* 1219 * The size of buf needs to be larger than DIRBLKSIZ. 1220 */ 1221 char buf[256 * 6]; 1222 1223 ASSERT_VOP_ELOCKED(vp, __func__); 1224 1225 eofflag = 0; 1226 uvp = UNIONFSVPTOUPPERVP(vp); 1227 lvp = UNIONFSVPTOLOWERVP(vp); 1228 1229 /* check opaque */ 1230 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) 1231 return (error); 1232 if (va.va_flags & OPAQUE) 1233 return (0); 1234 1235 /* open vnode */ 1236 #ifdef MAC 1237 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) 1238 return (error); 1239 #endif 1240 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) 1241 return (error); 1242 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) 1243 return (error); 1244 1245 uio.uio_rw = UIO_READ; 1246 uio.uio_segflg = UIO_SYSSPACE; 1247 uio.uio_td = td; 1248 uio.uio_offset = 0; 1249 1250 #ifdef MAC 1251 error = mac_vnode_check_readdir(td->td_ucred, lvp); 1252 #endif 1253 while (!error && !eofflag) { 1254 iov.iov_base = buf; 1255 iov.iov_len = sizeof(buf); 1256 uio.uio_iov = &iov; 1257 uio.uio_iovcnt = 1; 1258 uio.uio_resid = iov.iov_len; 1259 1260 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); 1261 if (error != 0) 1262 break; 1263 KASSERT(eofflag != 0 || uio.uio_resid < sizeof(buf), 1264 ("%s: empty read from lower FS", __func__)); 1265 1266 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; 1267 for (dp = (struct dirent*)buf; !error && dp < edp; 1268 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { 1269 if (dp->d_type == DT_WHT || dp->d_fileno == 0 || 1270 (dp->d_namlen == 1 && dp->d_name[0] == '.') || 1271 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) 1272 continue; 1273 1274 cn.cn_namelen = dp->d_namlen; 1275 cn.cn_pnbuf = NULL; 1276 cn.cn_nameptr = dp->d_name; 1277 cn.cn_nameiop = LOOKUP; 1278 cn.cn_flags = LOCKPARENT | LOCKLEAF | RDONLY | ISLASTCN; 1279 cn.cn_lkflags = LK_EXCLUSIVE; 1280 cn.cn_cred = cred; 1281 1282 /* 1283 * check entry in lower. 1284 * Sometimes, readdir function returns 1285 * wrong entry. 1286 */ 1287 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1288 1289 if (!lookuperr) 1290 vput(tvp); 1291 else 1292 continue; /* skip entry */ 1293 1294 /* 1295 * check entry 1296 * If it has no exist/whiteout entry in upper, 1297 * directory is not empty. 1298 */ 1299 cn.cn_flags = LOCKPARENT | LOCKLEAF | RDONLY | ISLASTCN; 1300 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1301 1302 if (!lookuperr) 1303 vput(tvp); 1304 1305 /* ignore exist or whiteout entry */ 1306 if (!lookuperr || 1307 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1308 continue; 1309 1310 error = ENOTEMPTY; 1311 } 1312 } 1313 1314 /* close vnode */ 1315 VOP_CLOSE(vp, FREAD, cred, td); 1316 1317 return (error); 1318 } 1319 1320