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