union_subr.c revision 190888
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 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc. 6 * Copyright (c) 2006 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: head/sys/fs/unionfs/union_subr.c 190888 2009-04-10 10:52:19Z rwatson $ 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#ifdef MAC 56#include <sys/mac.h> 57#endif 58 59#include <vm/uma.h> 60 61#include <fs/unionfs/union.h> 62 63#define NUNIONFSNODECACHE 16 64 65static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table"); 66MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part"); 67MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part"); 68 69/* 70 * Initialize 71 */ 72int 73unionfs_init(struct vfsconf *vfsp) 74{ 75 UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */ 76 return (0); 77} 78 79/* 80 * Uninitialize 81 */ 82int 83unionfs_uninit(struct vfsconf *vfsp) 84{ 85 return (0); 86} 87 88static struct unionfs_node_hashhead * 89unionfs_get_hashhead(struct vnode *dvp, char *path) 90{ 91 int count; 92 char hash; 93 struct unionfs_node *unp; 94 95 hash = 0; 96 unp = VTOUNIONFS(dvp); 97 if (path != NULL) { 98 for (count = 0; path[count]; count++) 99 hash += path[count]; 100 } 101 102 return (&(unp->un_hashtbl[hash & (unp->un_hashmask)])); 103} 104 105/* 106 * Get the cached vnode. 107 */ 108static struct vnode * 109unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp, 110 struct vnode *dvp, char *path) 111{ 112 struct unionfs_node_hashhead *hd; 113 struct unionfs_node *unp; 114 struct vnode *vp; 115 116 KASSERT((uvp == NULLVP || uvp->v_type == VDIR), 117 ("unionfs_get_cached_vnode: v_type != VDIR")); 118 KASSERT((lvp == NULLVP || lvp->v_type == VDIR), 119 ("unionfs_get_cached_vnode: v_type != VDIR")); 120 121 VI_LOCK(dvp); 122 hd = unionfs_get_hashhead(dvp, path); 123 LIST_FOREACH(unp, hd, un_hash) { 124 if (!strcmp(unp->un_path, path)) { 125 vp = UNIONFSTOV(unp); 126 VI_LOCK_FLAGS(vp, MTX_DUPOK); 127 VI_UNLOCK(dvp); 128 vp->v_iflag &= ~VI_OWEINACT; 129 if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) { 130 VI_UNLOCK(vp); 131 vp = NULLVP; 132 } else 133 VI_UNLOCK(vp); 134 return (vp); 135 } 136 } 137 VI_UNLOCK(dvp); 138 139 return (NULLVP); 140} 141 142/* 143 * Add the new vnode into cache. 144 */ 145static struct vnode * 146unionfs_ins_cached_vnode(struct unionfs_node *uncp, 147 struct vnode *dvp, char *path) 148{ 149 struct unionfs_node_hashhead *hd; 150 struct unionfs_node *unp; 151 struct vnode *vp; 152 153 KASSERT((uncp->un_uppervp==NULLVP || uncp->un_uppervp->v_type==VDIR), 154 ("unionfs_ins_cached_vnode: v_type != VDIR")); 155 KASSERT((uncp->un_lowervp==NULLVP || uncp->un_lowervp->v_type==VDIR), 156 ("unionfs_ins_cached_vnode: v_type != VDIR")); 157 158 VI_LOCK(dvp); 159 hd = unionfs_get_hashhead(dvp, path); 160 LIST_FOREACH(unp, hd, un_hash) { 161 if (!strcmp(unp->un_path, path)) { 162 vp = UNIONFSTOV(unp); 163 VI_LOCK_FLAGS(vp, MTX_DUPOK); 164 vp->v_iflag &= ~VI_OWEINACT; 165 if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) { 166 LIST_INSERT_HEAD(hd, uncp, un_hash); 167 VI_UNLOCK(vp); 168 vp = NULLVP; 169 } else 170 VI_UNLOCK(vp); 171 VI_UNLOCK(dvp); 172 return (vp); 173 } 174 } 175 176 LIST_INSERT_HEAD(hd, uncp, un_hash); 177 VI_UNLOCK(dvp); 178 179 return (NULLVP); 180} 181 182/* 183 * Remove the vnode. 184 */ 185static void 186unionfs_rem_cached_vnode(struct unionfs_node *unp, struct vnode *dvp) 187{ 188 KASSERT((unp != NULL), ("unionfs_rem_cached_vnode: null node")); 189 KASSERT((dvp != NULLVP), 190 ("unionfs_rem_cached_vnode: null parent vnode")); 191 KASSERT((unp->un_hash.le_prev != NULL), 192 ("unionfs_rem_cached_vnode: null hash")); 193 194 VI_LOCK(dvp); 195 LIST_REMOVE(unp, un_hash); 196 unp->un_hash.le_next = NULL; 197 unp->un_hash.le_prev = NULL; 198 VI_UNLOCK(dvp); 199} 200 201/* 202 * Make a new or get existing unionfs node. 203 * 204 * uppervp and lowervp should be unlocked. Because if new unionfs vnode is 205 * locked, uppervp or lowervp is locked too. In order to prevent dead lock, 206 * you should not lock plurality simultaneously. 207 */ 208int 209unionfs_nodeget(struct mount *mp, struct vnode *uppervp, 210 struct vnode *lowervp, struct vnode *dvp, 211 struct vnode **vpp, struct componentname *cnp, 212 struct thread *td) 213{ 214 struct unionfs_mount *ump; 215 struct unionfs_node *unp; 216 struct vnode *vp; 217 int error; 218 int lkflags; 219 enum vtype vt; 220 char *path; 221 222 ump = MOUNTTOUNIONFSMOUNT(mp); 223 lkflags = (cnp ? cnp->cn_lkflags : 0); 224 path = (cnp ? cnp->cn_nameptr : NULL); 225 *vpp = NULLVP; 226 227 if (uppervp == NULLVP && lowervp == NULLVP) 228 panic("unionfs_nodeget: upper and lower is null"); 229 230 vt = (uppervp != NULLVP ? uppervp->v_type : lowervp->v_type); 231 232 /* If it has no ISLASTCN flag, path check is skipped. */ 233 if (cnp && !(cnp->cn_flags & ISLASTCN)) 234 path = NULL; 235 236 /* check the cache */ 237 if (path != NULL && dvp != NULLVP && vt == VDIR) { 238 vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp, path); 239 if (vp != NULLVP) { 240 vref(vp); 241 *vpp = vp; 242 goto unionfs_nodeget_out; 243 } 244 } 245 246 if ((uppervp == NULLVP || ump->um_uppervp != uppervp) || 247 (lowervp == NULLVP || ump->um_lowervp != lowervp)) { 248 /* dvp will be NULLVP only in case of root vnode. */ 249 if (dvp == NULLVP) 250 return (EINVAL); 251 } 252 253 /* 254 * Do the MALLOC before the getnewvnode since doing so afterward 255 * might cause a bogus v_data pointer to get dereferenced elsewhere 256 * if MALLOC should block. 257 */ 258 unp = malloc(sizeof(struct unionfs_node), 259 M_UNIONFSNODE, M_WAITOK | M_ZERO); 260 261 error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp); 262 if (error != 0) { 263 free(unp, M_UNIONFSNODE); 264 return (error); 265 } 266 error = insmntque(vp, mp); /* XXX: Too early for mpsafe fs */ 267 if (error != 0) { 268 free(unp, M_UNIONFSNODE); 269 return (error); 270 } 271 if (dvp != NULLVP) 272 vref(dvp); 273 if (uppervp != NULLVP) 274 vref(uppervp); 275 if (lowervp != NULLVP) 276 vref(lowervp); 277 278 if (vt == VDIR) 279 unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, 280 &(unp->un_hashmask)); 281 282 unp->un_vnode = vp; 283 unp->un_uppervp = uppervp; 284 unp->un_lowervp = lowervp; 285 unp->un_dvp = dvp; 286 if (uppervp != NULLVP) 287 vp->v_vnlock = uppervp->v_vnlock; 288 else 289 vp->v_vnlock = lowervp->v_vnlock; 290 291 if (path != NULL) { 292 unp->un_path = (char *) 293 malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO); 294 bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen); 295 unp->un_path[cnp->cn_namelen] = '\0'; 296 } 297 vp->v_type = vt; 298 vp->v_data = unp; 299 300 if ((uppervp != NULLVP && ump->um_uppervp == uppervp) && 301 (lowervp != NULLVP && ump->um_lowervp == lowervp)) 302 vp->v_vflag |= VV_ROOT; 303 304 if (path != NULL && dvp != NULLVP && vt == VDIR) 305 *vpp = unionfs_ins_cached_vnode(unp, dvp, path); 306 if ((*vpp) != NULLVP) { 307 if (dvp != NULLVP) 308 vrele(dvp); 309 if (uppervp != NULLVP) 310 vrele(uppervp); 311 if (lowervp != NULLVP) 312 vrele(lowervp); 313 314 unp->un_uppervp = NULLVP; 315 unp->un_lowervp = NULLVP; 316 unp->un_dvp = NULLVP; 317 vrele(vp); 318 vp = *vpp; 319 vref(vp); 320 } else 321 *vpp = vp; 322 323unionfs_nodeget_out: 324 if (lkflags & LK_TYPE_MASK) 325 vn_lock(vp, lkflags | LK_RETRY); 326 327 return (0); 328} 329 330/* 331 * Clean up the unionfs node. 332 */ 333void 334unionfs_noderem(struct vnode *vp, struct thread *td) 335{ 336 int vfslocked; 337 int count; 338 struct unionfs_node *unp, *unp_t1, *unp_t2; 339 struct unionfs_node_hashhead *hd; 340 struct unionfs_node_status *unsp, *unsp_tmp; 341 struct vnode *lvp; 342 struct vnode *uvp; 343 struct vnode *dvp; 344 345 /* 346 * Use the interlock to protect the clearing of v_data to 347 * prevent faults in unionfs_lock(). 348 */ 349 VI_LOCK(vp); 350 unp = VTOUNIONFS(vp); 351 lvp = unp->un_lowervp; 352 uvp = unp->un_uppervp; 353 dvp = unp->un_dvp; 354 unp->un_lowervp = unp->un_uppervp = NULLVP; 355 356 vp->v_vnlock = &(vp->v_lock); 357 vp->v_data = NULL; 358 lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_INTERLOCK, VI_MTX(vp)); 359 if (lvp != NULLVP) 360 VOP_UNLOCK(lvp, 0); 361 if (uvp != NULLVP) 362 VOP_UNLOCK(uvp, 0); 363 vp->v_object = NULL; 364 365 if (dvp != NULLVP && unp->un_hash.le_prev != NULL) 366 unionfs_rem_cached_vnode(unp, dvp); 367 368 if (lvp != NULLVP) { 369 vfslocked = VFS_LOCK_GIANT(lvp->v_mount); 370 vrele(lvp); 371 VFS_UNLOCK_GIANT(vfslocked); 372 } 373 if (uvp != NULLVP) { 374 vfslocked = VFS_LOCK_GIANT(uvp->v_mount); 375 vrele(uvp); 376 VFS_UNLOCK_GIANT(vfslocked); 377 } 378 if (dvp != NULLVP) { 379 vfslocked = VFS_LOCK_GIANT(dvp->v_mount); 380 vrele(dvp); 381 VFS_UNLOCK_GIANT(vfslocked); 382 unp->un_dvp = NULLVP; 383 } 384 if (unp->un_path != NULL) { 385 free(unp->un_path, M_UNIONFSPATH); 386 unp->un_path = NULL; 387 } 388 389 if (unp->un_hashtbl != NULL) { 390 for (count = 0; count <= unp->un_hashmask; count++) { 391 hd = unp->un_hashtbl + count; 392 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { 393 LIST_REMOVE(unp_t1, un_hash); 394 unp_t1->un_hash.le_next = NULL; 395 unp_t1->un_hash.le_prev = NULL; 396 } 397 } 398 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask); 399 } 400 401 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { 402 LIST_REMOVE(unsp, uns_list); 403 free(unsp, M_TEMP); 404 } 405 free(unp, M_UNIONFSNODE); 406} 407 408/* 409 * Get the unionfs node status. 410 * You need exclusive lock this vnode. 411 */ 412void 413unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, 414 struct unionfs_node_status **unspp) 415{ 416 struct unionfs_node_status *unsp; 417 pid_t pid = td->td_proc->p_pid; 418 419 KASSERT(NULL != unspp, ("null pointer")); 420 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 421 422 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { 423 if (unsp->uns_pid == pid) { 424 *unspp = unsp; 425 return; 426 } 427 } 428 429 /* create a new unionfs node status */ 430 unsp = malloc(sizeof(struct unionfs_node_status), 431 M_TEMP, M_WAITOK | M_ZERO); 432 433 unsp->uns_pid = pid; 434 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); 435 436 *unspp = unsp; 437} 438 439/* 440 * Remove the unionfs node status, if you can. 441 * You need exclusive lock this vnode. 442 */ 443void 444unionfs_tryrem_node_status(struct unionfs_node *unp, 445 struct unionfs_node_status *unsp) 446{ 447 KASSERT(NULL != unsp, ("null pointer")); 448 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 449 450 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) 451 return; 452 453 LIST_REMOVE(unsp, uns_list); 454 free(unsp, M_TEMP); 455} 456 457/* 458 * Create upper node attr. 459 */ 460void 461unionfs_create_uppervattr_core(struct unionfs_mount *ump, 462 struct vattr *lva, 463 struct vattr *uva, 464 struct thread *td) 465{ 466 VATTR_NULL(uva); 467 uva->va_type = lva->va_type; 468 uva->va_atime = lva->va_atime; 469 uva->va_mtime = lva->va_mtime; 470 uva->va_ctime = lva->va_ctime; 471 472 switch (ump->um_copymode) { 473 case UNIONFS_TRANSPARENT: 474 uva->va_mode = lva->va_mode; 475 uva->va_uid = lva->va_uid; 476 uva->va_gid = lva->va_gid; 477 break; 478 case UNIONFS_MASQUERADE: 479 if (ump->um_uid == lva->va_uid) { 480 uva->va_mode = lva->va_mode & 077077; 481 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700; 482 uva->va_uid = lva->va_uid; 483 uva->va_gid = lva->va_gid; 484 } else { 485 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile); 486 uva->va_uid = ump->um_uid; 487 uva->va_gid = ump->um_gid; 488 } 489 break; 490 default: /* UNIONFS_TRADITIONAL */ 491 FILEDESC_SLOCK(td->td_proc->p_fd); 492 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask; 493 FILEDESC_SUNLOCK(td->td_proc->p_fd); 494 uva->va_uid = ump->um_uid; 495 uva->va_gid = ump->um_gid; 496 break; 497 } 498} 499 500/* 501 * Create upper node attr. 502 */ 503int 504unionfs_create_uppervattr(struct unionfs_mount *ump, 505 struct vnode *lvp, 506 struct vattr *uva, 507 struct ucred *cred, 508 struct thread *td) 509{ 510 int error; 511 struct vattr lva; 512 513 if ((error = VOP_GETATTR(lvp, &lva, cred))) 514 return (error); 515 516 unionfs_create_uppervattr_core(ump, &lva, uva, td); 517 518 return (error); 519} 520 521/* 522 * relookup 523 * 524 * dvp should be locked on entry and will be locked on return. 525 * 526 * If an error is returned, *vpp will be invalid, otherwise it will hold a 527 * locked, referenced vnode. If *vpp == dvp then remember that only one 528 * LK_EXCLUSIVE lock is held. 529 */ 530int 531unionfs_relookup(struct vnode *dvp, struct vnode **vpp, 532 struct componentname *cnp, struct componentname *cn, 533 struct thread *td, char *path, int pathlen, u_long nameiop) 534{ 535 int error; 536 537 cn->cn_namelen = pathlen; 538 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 539 bcopy(path, cn->cn_pnbuf, pathlen); 540 cn->cn_pnbuf[pathlen] = '\0'; 541 542 cn->cn_nameiop = nameiop; 543 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 544 cn->cn_lkflags = LK_EXCLUSIVE; 545 cn->cn_thread = td; 546 cn->cn_cred = cnp->cn_cred; 547 548 cn->cn_nameptr = cn->cn_pnbuf; 549 cn->cn_consume = cnp->cn_consume; 550 551 if (nameiop == DELETE) 552 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); 553 else if (RENAME == nameiop) 554 cn->cn_flags |= (cnp->cn_flags & SAVESTART); 555 556 vref(dvp); 557 VOP_UNLOCK(dvp, 0); 558 559 if ((error = relookup(dvp, vpp, cn))) { 560 uma_zfree(namei_zone, cn->cn_pnbuf); 561 cn->cn_flags &= ~HASBUF; 562 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 563 } else 564 vrele(dvp); 565 566 return (error); 567} 568 569/* 570 * relookup for CREATE namei operation. 571 * 572 * dvp is unionfs vnode. dvp should be locked. 573 * 574 * If it called 'unionfs_copyfile' function by unionfs_link etc, 575 * VOP_LOOKUP information is broken. 576 * So it need relookup in order to create link etc. 577 */ 578int 579unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 580 struct thread *td) 581{ 582 int error; 583 struct vnode *udvp; 584 struct vnode *vp; 585 struct componentname cn; 586 587 udvp = UNIONFSVPTOUPPERVP(dvp); 588 vp = NULLVP; 589 590 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 591 strlen(cnp->cn_nameptr), CREATE); 592 if (error) 593 return (error); 594 595 if (vp != NULLVP) { 596 if (udvp == vp) 597 vrele(vp); 598 else 599 vput(vp); 600 601 error = EEXIST; 602 } 603 604 if (cn.cn_flags & HASBUF) { 605 uma_zfree(namei_zone, cn.cn_pnbuf); 606 cn.cn_flags &= ~HASBUF; 607 } 608 609 if (!error) { 610 cn.cn_flags |= (cnp->cn_flags & HASBUF); 611 cnp->cn_flags = cn.cn_flags; 612 } 613 614 return (error); 615} 616 617/* 618 * relookup for DELETE namei operation. 619 * 620 * dvp is unionfs vnode. dvp should be locked. 621 */ 622int 623unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 624 struct thread *td) 625{ 626 int error; 627 struct vnode *udvp; 628 struct vnode *vp; 629 struct componentname cn; 630 631 udvp = UNIONFSVPTOUPPERVP(dvp); 632 vp = NULLVP; 633 634 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 635 strlen(cnp->cn_nameptr), DELETE); 636 if (error) 637 return (error); 638 639 if (vp == NULLVP) 640 error = ENOENT; 641 else { 642 if (udvp == vp) 643 vrele(vp); 644 else 645 vput(vp); 646 } 647 648 if (cn.cn_flags & HASBUF) { 649 uma_zfree(namei_zone, cn.cn_pnbuf); 650 cn.cn_flags &= ~HASBUF; 651 } 652 653 if (!error) { 654 cn.cn_flags |= (cnp->cn_flags & HASBUF); 655 cnp->cn_flags = cn.cn_flags; 656 } 657 658 return (error); 659} 660 661/* 662 * relookup for RENAME namei operation. 663 * 664 * dvp is unionfs vnode. dvp should be locked. 665 */ 666int 667unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 668 struct thread *td) 669{ 670 int error; 671 struct vnode *udvp; 672 struct vnode *vp; 673 struct componentname cn; 674 675 udvp = UNIONFSVPTOUPPERVP(dvp); 676 vp = NULLVP; 677 678 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 679 strlen(cnp->cn_nameptr), RENAME); 680 if (error) 681 return (error); 682 683 if (vp != NULLVP) { 684 if (udvp == vp) 685 vrele(vp); 686 else 687 vput(vp); 688 } 689 690 if (cn.cn_flags & HASBUF) { 691 uma_zfree(namei_zone, cn.cn_pnbuf); 692 cn.cn_flags &= ~HASBUF; 693 } 694 695 if (!error) { 696 cn.cn_flags |= (cnp->cn_flags & HASBUF); 697 cnp->cn_flags = cn.cn_flags; 698 } 699 700 return (error); 701 702} 703 704/* 705 * Update the unionfs_node. 706 * 707 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 708 * uvp's lock and lower's lock will be unlocked. 709 */ 710static void 711unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 712 struct thread *td) 713{ 714 unsigned count, lockrec; 715 struct vnode *vp; 716 struct vnode *lvp; 717 struct vnode *dvp; 718 719 vp = UNIONFSTOV(unp); 720 lvp = unp->un_lowervp; 721 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); 722 dvp = unp->un_dvp; 723 724 /* 725 * lock update 726 */ 727 VI_LOCK(vp); 728 unp->un_uppervp = uvp; 729 vp->v_vnlock = uvp->v_vnlock; 730 VI_UNLOCK(vp); 731 lockrec = lvp->v_vnlock->lk_recurse; 732 for (count = 0; count < lockrec; count++) 733 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 734 735 /* 736 * cache update 737 */ 738 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { 739 static struct unionfs_node_hashhead *hd; 740 741 VI_LOCK(dvp); 742 hd = unionfs_get_hashhead(dvp, unp->un_path); 743 LIST_REMOVE(unp, un_hash); 744 LIST_INSERT_HEAD(hd, unp, un_hash); 745 VI_UNLOCK(dvp); 746 } 747} 748 749/* 750 * Create a new shadow dir. 751 * 752 * udvp should be locked on entry and will be locked on return. 753 * 754 * If no error returned, unp will be updated. 755 */ 756int 757unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 758 struct unionfs_node *unp, struct componentname *cnp, 759 struct thread *td) 760{ 761 int error; 762 struct vnode *lvp; 763 struct vnode *uvp; 764 struct vattr va; 765 struct vattr lva; 766 struct componentname cn; 767 struct mount *mp; 768 struct ucred *cred; 769 struct ucred *credbk; 770 struct uidinfo *rootinfo; 771 772 if (unp->un_uppervp != NULLVP) 773 return (EEXIST); 774 775 lvp = unp->un_lowervp; 776 uvp = NULLVP; 777 credbk = cnp->cn_cred; 778 779 /* Authority change to root */ 780 rootinfo = uifind((uid_t)0); 781 cred = crdup(cnp->cn_cred); 782 chgproccnt(cred->cr_ruidinfo, 1, 0); 783 change_euid(cred, rootinfo); 784 change_ruid(cred, rootinfo); 785 change_svuid(cred, (uid_t)0); 786 uifree(rootinfo); 787 cnp->cn_cred = cred; 788 789 memset(&cn, 0, sizeof(cn)); 790 791 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 792 goto unionfs_mkshadowdir_abort; 793 794 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 795 goto unionfs_mkshadowdir_abort; 796 if (uvp != NULLVP) { 797 if (udvp == uvp) 798 vrele(uvp); 799 else 800 vput(uvp); 801 802 error = EEXIST; 803 goto unionfs_mkshadowdir_free_out; 804 } 805 806 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) 807 goto unionfs_mkshadowdir_free_out; 808 unionfs_create_uppervattr_core(ump, &lva, &va, td); 809 810 error = VOP_MKDIR(udvp, &uvp, &cn, &va); 811 812 if (!error) { 813 unionfs_node_update(unp, uvp, td); 814 815 /* 816 * XXX The bug which cannot set uid/gid was corrected. 817 * Ignore errors. 818 */ 819 va.va_type = VNON; 820 VOP_SETATTR(uvp, &va, cn.cn_cred); 821 } 822 vn_finished_write(mp); 823 824unionfs_mkshadowdir_free_out: 825 if (cn.cn_flags & HASBUF) { 826 uma_zfree(namei_zone, cn.cn_pnbuf); 827 cn.cn_flags &= ~HASBUF; 828 } 829 830unionfs_mkshadowdir_abort: 831 cnp->cn_cred = credbk; 832 chgproccnt(cred->cr_ruidinfo, -1, 0); 833 crfree(cred); 834 835 return (error); 836} 837 838/* 839 * Create a new whiteout. 840 * 841 * dvp should be locked on entry and will be locked on return. 842 */ 843int 844unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 845 struct thread *td, char *path) 846{ 847 int error; 848 struct vnode *wvp; 849 struct componentname cn; 850 struct mount *mp; 851 852 if (path == NULL) 853 path = cnp->cn_nameptr; 854 855 wvp = NULLVP; 856 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) 857 return (error); 858 if (wvp != NULLVP) { 859 if (cn.cn_flags & HASBUF) { 860 uma_zfree(namei_zone, cn.cn_pnbuf); 861 cn.cn_flags &= ~HASBUF; 862 } 863 if (dvp == wvp) 864 vrele(wvp); 865 else 866 vput(wvp); 867 868 return (EEXIST); 869 } 870 871 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) 872 goto unionfs_mkwhiteout_free_out; 873 error = VOP_WHITEOUT(dvp, &cn, CREATE); 874 875 vn_finished_write(mp); 876 877unionfs_mkwhiteout_free_out: 878 if (cn.cn_flags & HASBUF) { 879 uma_zfree(namei_zone, cn.cn_pnbuf); 880 cn.cn_flags &= ~HASBUF; 881 } 882 883 return (error); 884} 885 886/* 887 * Create a new vnode for create a new shadow file. 888 * 889 * If an error is returned, *vpp will be invalid, otherwise it will hold a 890 * locked, referenced and opened vnode. 891 * 892 * unp is never updated. 893 */ 894static int 895unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 896 struct unionfs_node *unp, struct vattr *uvap, 897 struct thread *td) 898{ 899 struct unionfs_mount *ump; 900 struct vnode *vp; 901 struct vnode *lvp; 902 struct ucred *cred; 903 struct vattr lva; 904 int fmode; 905 int error; 906 struct componentname cn; 907 908 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 909 vp = NULLVP; 910 lvp = unp->un_lowervp; 911 cred = td->td_ucred; 912 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 913 error = 0; 914 915 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 916 return (error); 917 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 918 919 if (unp->un_path == NULL) 920 panic("unionfs: un_path is null"); 921 922 cn.cn_namelen = strlen(unp->un_path); 923 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 924 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); 925 cn.cn_nameiop = CREATE; 926 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 927 cn.cn_lkflags = LK_EXCLUSIVE; 928 cn.cn_thread = td; 929 cn.cn_cred = cred; 930 cn.cn_nameptr = cn.cn_pnbuf; 931 cn.cn_consume = 0; 932 933 vref(udvp); 934 if ((error = relookup(udvp, &vp, &cn)) != 0) 935 goto unionfs_vn_create_on_upper_free_out2; 936 vrele(udvp); 937 938 if (vp != NULLVP) { 939 if (vp == udvp) 940 vrele(vp); 941 else 942 vput(vp); 943 error = EEXIST; 944 goto unionfs_vn_create_on_upper_free_out1; 945 } 946 947 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0) 948 goto unionfs_vn_create_on_upper_free_out1; 949 950 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { 951 vput(vp); 952 goto unionfs_vn_create_on_upper_free_out1; 953 } 954 vp->v_writecount++; 955 *vpp = vp; 956 957unionfs_vn_create_on_upper_free_out1: 958 VOP_UNLOCK(udvp, 0); 959 960unionfs_vn_create_on_upper_free_out2: 961 if (cn.cn_flags & HASBUF) { 962 uma_zfree(namei_zone, cn.cn_pnbuf); 963 cn.cn_flags &= ~HASBUF; 964 } 965 966 return (error); 967} 968 969/* 970 * Copy from lvp to uvp. 971 * 972 * lvp and uvp should be locked and opened on entry and will be locked and 973 * opened on return. 974 */ 975static int 976unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, 977 struct ucred *cred, struct thread *td) 978{ 979 int error; 980 off_t offset; 981 int count; 982 int bufoffset; 983 char *buf; 984 struct uio uio; 985 struct iovec iov; 986 987 error = 0; 988 memset(&uio, 0, sizeof(uio)); 989 990 uio.uio_td = td; 991 uio.uio_segflg = UIO_SYSSPACE; 992 uio.uio_offset = 0; 993 994 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); 995 996 while (error == 0) { 997 offset = uio.uio_offset; 998 999 uio.uio_iov = &iov; 1000 uio.uio_iovcnt = 1; 1001 iov.iov_base = buf; 1002 iov.iov_len = MAXBSIZE; 1003 uio.uio_resid = iov.iov_len; 1004 uio.uio_rw = UIO_READ; 1005 1006 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) 1007 break; 1008 if ((count = MAXBSIZE - uio.uio_resid) == 0) 1009 break; 1010 1011 bufoffset = 0; 1012 while (bufoffset < count) { 1013 uio.uio_iov = &iov; 1014 uio.uio_iovcnt = 1; 1015 iov.iov_base = buf + bufoffset; 1016 iov.iov_len = count - bufoffset; 1017 uio.uio_offset = offset + bufoffset; 1018 uio.uio_resid = iov.iov_len; 1019 uio.uio_rw = UIO_WRITE; 1020 1021 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) 1022 break; 1023 1024 bufoffset += (count - bufoffset) - uio.uio_resid; 1025 } 1026 1027 uio.uio_offset = offset + bufoffset; 1028 } 1029 1030 free(buf, M_TEMP); 1031 1032 return (error); 1033} 1034 1035/* 1036 * Copy file from lower to upper. 1037 * 1038 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to 1039 * docopy. 1040 * 1041 * If no error returned, unp will be updated. 1042 */ 1043int 1044unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, 1045 struct thread *td) 1046{ 1047 int error; 1048 struct mount *mp; 1049 struct vnode *udvp; 1050 struct vnode *lvp; 1051 struct vnode *uvp; 1052 struct vattr uva; 1053 1054 lvp = unp->un_lowervp; 1055 uvp = NULLVP; 1056 1057 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) 1058 return (EROFS); 1059 if (unp->un_dvp == NULLVP) 1060 return (EINVAL); 1061 if (unp->un_uppervp != NULLVP) 1062 return (EEXIST); 1063 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; 1064 if (udvp == NULLVP) 1065 return (EROFS); 1066 if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) 1067 return (EROFS); 1068 1069 error = VOP_ACCESS(lvp, VREAD, cred, td); 1070 if (error != 0) 1071 return (error); 1072 1073 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0) 1074 return (error); 1075 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); 1076 if (error != 0) { 1077 vn_finished_write(mp); 1078 return (error); 1079 } 1080 1081 if (docopy != 0) { 1082 error = VOP_OPEN(lvp, FREAD, cred, td, NULL); 1083 if (error == 0) { 1084 error = unionfs_copyfile_core(lvp, uvp, cred, td); 1085 VOP_CLOSE(lvp, FREAD, cred, td); 1086 } 1087 } 1088 VOP_CLOSE(uvp, FWRITE, cred, td); 1089 uvp->v_writecount--; 1090 1091 vn_finished_write(mp); 1092 1093 if (error == 0) { 1094 /* Reset the attributes. Ignore errors. */ 1095 uva.va_type = VNON; 1096 VOP_SETATTR(uvp, &uva, cred); 1097 } 1098 1099 unionfs_node_update(unp, uvp, td); 1100 1101 return (error); 1102} 1103 1104/* 1105 * It checks whether vp can rmdir. (check empty) 1106 * 1107 * vp is unionfs vnode. 1108 * vp should be locked. 1109 */ 1110int 1111unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) 1112{ 1113 int error; 1114 int eofflag; 1115 int lookuperr; 1116 struct vnode *uvp; 1117 struct vnode *lvp; 1118 struct vnode *tvp; 1119 struct vattr va; 1120 struct componentname cn; 1121 /* 1122 * The size of buf needs to be larger than DIRBLKSIZ. 1123 */ 1124 char buf[256 * 6]; 1125 struct dirent *dp; 1126 struct dirent *edp; 1127 struct uio uio; 1128 struct iovec iov; 1129 1130 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir"); 1131 1132 eofflag = 0; 1133 uvp = UNIONFSVPTOUPPERVP(vp); 1134 lvp = UNIONFSVPTOLOWERVP(vp); 1135 1136 /* check opaque */ 1137 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) 1138 return (error); 1139 if (va.va_flags & OPAQUE) 1140 return (0); 1141 1142 /* open vnode */ 1143#ifdef MAC 1144 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) 1145 return (error); 1146#endif 1147 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) 1148 return (error); 1149 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) 1150 return (error); 1151 1152 uio.uio_rw = UIO_READ; 1153 uio.uio_segflg = UIO_SYSSPACE; 1154 uio.uio_td = td; 1155 uio.uio_offset = 0; 1156 1157#ifdef MAC 1158 error = mac_vnode_check_readdir(td->td_ucred, lvp); 1159#endif 1160 while (!error && !eofflag) { 1161 iov.iov_base = buf; 1162 iov.iov_len = sizeof(buf); 1163 uio.uio_iov = &iov; 1164 uio.uio_iovcnt = 1; 1165 uio.uio_resid = iov.iov_len; 1166 1167 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); 1168 if (error != 0) 1169 break; 1170 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) { 1171#ifdef DIAGNOSTIC 1172 panic("bad readdir response from lower FS."); 1173#endif 1174 break; 1175 } 1176 1177 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; 1178 for (dp = (struct dirent*)buf; !error && dp < edp; 1179 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { 1180 if (dp->d_type == DT_WHT || 1181 (dp->d_namlen == 1 && dp->d_name[0] == '.') || 1182 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) 1183 continue; 1184 1185 cn.cn_namelen = dp->d_namlen; 1186 cn.cn_pnbuf = NULL; 1187 cn.cn_nameptr = dp->d_name; 1188 cn.cn_nameiop = LOOKUP; 1189 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1190 cn.cn_lkflags = LK_EXCLUSIVE; 1191 cn.cn_thread = td; 1192 cn.cn_cred = cred; 1193 cn.cn_consume = 0; 1194 1195 /* 1196 * check entry in lower. 1197 * Sometimes, readdir function returns 1198 * wrong entry. 1199 */ 1200 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1201 1202 if (!lookuperr) 1203 vput(tvp); 1204 else 1205 continue; /* skip entry */ 1206 1207 /* 1208 * check entry 1209 * If it has no exist/whiteout entry in upper, 1210 * directory is not empty. 1211 */ 1212 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1213 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1214 1215 if (!lookuperr) 1216 vput(tvp); 1217 1218 /* ignore exist or whiteout entry */ 1219 if (!lookuperr || 1220 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1221 continue; 1222 1223 error = ENOTEMPTY; 1224 } 1225 } 1226 1227 /* close vnode */ 1228 VOP_CLOSE(vp, FREAD, cred, td); 1229 1230 return (error); 1231} 1232 1233#ifdef DIAGNOSTIC 1234 1235struct vnode * 1236unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) 1237{ 1238 struct unionfs_node *unp; 1239 1240 unp = VTOUNIONFS(vp); 1241 1242#ifdef notyet 1243 if (vp->v_op != unionfs_vnodeop_p) { 1244 printf("unionfs_checkuppervp: on non-unionfs-node.\n"); 1245#ifdef KDB 1246 kdb_enter(KDB_WHY_UNIONFS, 1247 "unionfs_checkuppervp: on non-unionfs-node.\n"); 1248#endif 1249 panic("unionfs_checkuppervp"); 1250 }; 1251#endif 1252 return (unp->un_uppervp); 1253} 1254 1255struct vnode * 1256unionfs_checklowervp(struct vnode *vp, char *fil, int lno) 1257{ 1258 struct unionfs_node *unp; 1259 1260 unp = VTOUNIONFS(vp); 1261 1262#ifdef notyet 1263 if (vp->v_op != unionfs_vnodeop_p) { 1264 printf("unionfs_checklowervp: on non-unionfs-node.\n"); 1265#ifdef KDB 1266 kdb_enter(KDB_WHY_UNIONFS, 1267 "unionfs_checklowervp: on non-unionfs-node.\n"); 1268#endif 1269 panic("unionfs_checklowervp"); 1270 }; 1271#endif 1272 return (unp->un_lowervp); 1273} 1274#endif 1275