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sys/fs/unionfs/union_subr.c
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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: releng/12.0/sys/fs/unionfs/union_subr.c 326023 2017-11-20 19:43:44Z pfg $ 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/mutex.h> 46 #include <sys/malloc.h> 47 #include <sys/mount.h> 48 #include <sys/namei.h> 49 #include <sys/proc.h> 50 #include <sys/vnode.h> 51 #include <sys/dirent.h> 52 #include <sys/fcntl.h> 53 #include <sys/filedesc.h> 54 #include <sys/stat.h> 55 #include <sys/resourcevar.h> 56 57 #include <security/mac/mac_framework.h> 58 59 #include <vm/uma.h> 60 61 #include <fs/unionfs/union.h> 62 63 #define NUNIONFSNODECACHE 16 64 65 static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table"); 66 MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part"); 67 MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part"); 68 69 /* 70 * Initialize 71 */ 72 int 73 unionfs_init(struct vfsconf *vfsp) 74 { 75 UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */ 76 return (0); 77 } 78 79 /* 80 * Uninitialize 81 */ 82 int 83 unionfs_uninit(struct vfsconf *vfsp) 84 { 85 return (0); 86 } 87 88 static struct unionfs_node_hashhead * 89 unionfs_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 */ 108 static struct vnode * 109 unionfs_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 */ 145 static struct vnode * 146 unionfs_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 */ 185 static void 186 unionfs_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 */ 208 int 209 unionfs_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 unp = malloc(sizeof(struct unionfs_node), 253 M_UNIONFSNODE, M_WAITOK | M_ZERO); 254 255 error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp); 256 if (error != 0) { 257 free(unp, M_UNIONFSNODE); 258 return (error); 259 } 260 error = insmntque(vp, mp); /* XXX: Too early for mpsafe fs */ 261 if (error != 0) { 262 free(unp, M_UNIONFSNODE); 263 return (error); 264 } 265 if (dvp != NULLVP) 266 vref(dvp); 267 if (uppervp != NULLVP) 268 vref(uppervp); 269 if (lowervp != NULLVP) 270 vref(lowervp); 271 272 if (vt == VDIR) 273 unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, 274 &(unp->un_hashmask)); 275 276 unp->un_vnode = vp; 277 unp->un_uppervp = uppervp; 278 unp->un_lowervp = lowervp; 279 unp->un_dvp = dvp; 280 if (uppervp != NULLVP) 281 vp->v_vnlock = uppervp->v_vnlock; 282 else 283 vp->v_vnlock = lowervp->v_vnlock; 284 285 if (path != NULL) { 286 unp->un_path = (char *) 287 malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO); 288 bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen); 289 unp->un_path[cnp->cn_namelen] = '\0'; 290 } 291 vp->v_type = vt; 292 vp->v_data = unp; 293 294 if ((uppervp != NULLVP && ump->um_uppervp == uppervp) && 295 (lowervp != NULLVP && ump->um_lowervp == lowervp)) 296 vp->v_vflag |= VV_ROOT; 297 298 if (path != NULL && dvp != NULLVP && vt == VDIR) 299 *vpp = unionfs_ins_cached_vnode(unp, dvp, path); 300 if ((*vpp) != NULLVP) { 301 if (dvp != NULLVP) 302 vrele(dvp); 303 if (uppervp != NULLVP) 304 vrele(uppervp); 305 if (lowervp != NULLVP) 306 vrele(lowervp); 307 308 unp->un_uppervp = NULLVP; 309 unp->un_lowervp = NULLVP; 310 unp->un_dvp = NULLVP; 311 vrele(vp); 312 vp = *vpp; 313 vref(vp); 314 } else 315 *vpp = vp; 316 317 unionfs_nodeget_out: 318 if (lkflags & LK_TYPE_MASK) 319 vn_lock(vp, lkflags | LK_RETRY); 320 321 return (0); 322 } 323 324 /* 325 * Clean up the unionfs node. 326 */ 327 void 328 unionfs_noderem(struct vnode *vp, struct thread *td) 329 { 330 int count; 331 struct unionfs_node *unp, *unp_t1, *unp_t2; 332 struct unionfs_node_hashhead *hd; 333 struct unionfs_node_status *unsp, *unsp_tmp; 334 struct vnode *lvp; 335 struct vnode *uvp; 336 struct vnode *dvp; 337 338 /* 339 * Use the interlock to protect the clearing of v_data to 340 * prevent faults in unionfs_lock(). 341 */ 342 VI_LOCK(vp); 343 unp = VTOUNIONFS(vp); 344 lvp = unp->un_lowervp; 345 uvp = unp->un_uppervp; 346 dvp = unp->un_dvp; 347 unp->un_lowervp = unp->un_uppervp = NULLVP; 348 vp->v_vnlock = &(vp->v_lock); 349 vp->v_data = NULL; 350 vp->v_object = NULL; 351 VI_UNLOCK(vp); 352 353 if (lvp != NULLVP) 354 VOP_UNLOCK(lvp, LK_RELEASE); 355 if (uvp != NULLVP) 356 VOP_UNLOCK(uvp, LK_RELEASE); 357 358 if (dvp != NULLVP && unp->un_hash.le_prev != NULL) 359 unionfs_rem_cached_vnode(unp, dvp); 360 361 if (lockmgr(vp->v_vnlock, LK_EXCLUSIVE, VI_MTX(vp)) != 0) 362 panic("the lock for deletion is unacquirable."); 363 364 if (lvp != NULLVP) 365 vrele(lvp); 366 if (uvp != NULLVP) 367 vrele(uvp); 368 if (dvp != NULLVP) { 369 vrele(dvp); 370 unp->un_dvp = NULLVP; 371 } 372 if (unp->un_path != NULL) { 373 free(unp->un_path, M_UNIONFSPATH); 374 unp->un_path = NULL; 375 } 376 377 if (unp->un_hashtbl != NULL) { 378 for (count = 0; count <= unp->un_hashmask; count++) { 379 hd = unp->un_hashtbl + count; 380 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { 381 LIST_REMOVE(unp_t1, un_hash); 382 unp_t1->un_hash.le_next = NULL; 383 unp_t1->un_hash.le_prev = NULL; 384 } 385 } 386 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask); 387 } 388 389 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { 390 LIST_REMOVE(unsp, uns_list); 391 free(unsp, M_TEMP); 392 } 393 free(unp, M_UNIONFSNODE); 394 } 395 396 /* 397 * Get the unionfs node status. 398 * You need exclusive lock this vnode. 399 */ 400 void 401 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, 402 struct unionfs_node_status **unspp) 403 { 404 struct unionfs_node_status *unsp; 405 pid_t pid = td->td_proc->p_pid; 406 407 KASSERT(NULL != unspp, ("null pointer")); 408 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 409 410 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { 411 if (unsp->uns_pid == pid) { 412 *unspp = unsp; 413 return; 414 } 415 } 416 417 /* create a new unionfs node status */ 418 unsp = malloc(sizeof(struct unionfs_node_status), 419 M_TEMP, M_WAITOK | M_ZERO); 420 421 unsp->uns_pid = pid; 422 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); 423 424 *unspp = unsp; 425 } 426 427 /* 428 * Remove the unionfs node status, if you can. 429 * You need exclusive lock this vnode. 430 */ 431 void 432 unionfs_tryrem_node_status(struct unionfs_node *unp, 433 struct unionfs_node_status *unsp) 434 { 435 KASSERT(NULL != unsp, ("null pointer")); 436 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 437 438 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) 439 return; 440 441 LIST_REMOVE(unsp, uns_list); 442 free(unsp, M_TEMP); 443 } 444 445 /* 446 * Create upper node attr. 447 */ 448 void 449 unionfs_create_uppervattr_core(struct unionfs_mount *ump, 450 struct vattr *lva, 451 struct vattr *uva, 452 struct thread *td) 453 { 454 VATTR_NULL(uva); 455 uva->va_type = lva->va_type; 456 uva->va_atime = lva->va_atime; 457 uva->va_mtime = lva->va_mtime; 458 uva->va_ctime = lva->va_ctime; 459 460 switch (ump->um_copymode) { 461 case UNIONFS_TRANSPARENT: 462 uva->va_mode = lva->va_mode; 463 uva->va_uid = lva->va_uid; 464 uva->va_gid = lva->va_gid; 465 break; 466 case UNIONFS_MASQUERADE: 467 if (ump->um_uid == lva->va_uid) { 468 uva->va_mode = lva->va_mode & 077077; 469 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700; 470 uva->va_uid = lva->va_uid; 471 uva->va_gid = lva->va_gid; 472 } else { 473 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile); 474 uva->va_uid = ump->um_uid; 475 uva->va_gid = ump->um_gid; 476 } 477 break; 478 default: /* UNIONFS_TRADITIONAL */ 479 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask; 480 uva->va_uid = ump->um_uid; 481 uva->va_gid = ump->um_gid; 482 break; 483 } 484 } 485 486 /* 487 * Create upper node attr. 488 */ 489 int 490 unionfs_create_uppervattr(struct unionfs_mount *ump, 491 struct vnode *lvp, 492 struct vattr *uva, 493 struct ucred *cred, 494 struct thread *td) 495 { 496 int error; 497 struct vattr lva; 498 499 if ((error = VOP_GETATTR(lvp, &lva, cred))) 500 return (error); 501 502 unionfs_create_uppervattr_core(ump, &lva, uva, td); 503 504 return (error); 505 } 506 507 /* 508 * relookup 509 * 510 * dvp should be locked on entry and will be locked on return. 511 * 512 * If an error is returned, *vpp will be invalid, otherwise it will hold a 513 * locked, referenced vnode. If *vpp == dvp then remember that only one 514 * LK_EXCLUSIVE lock is held. 515 */ 516 int 517 unionfs_relookup(struct vnode *dvp, struct vnode **vpp, 518 struct componentname *cnp, struct componentname *cn, 519 struct thread *td, char *path, int pathlen, u_long nameiop) 520 { 521 int error; 522 523 cn->cn_namelen = pathlen; 524 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 525 bcopy(path, cn->cn_pnbuf, pathlen); 526 cn->cn_pnbuf[pathlen] = '\0'; 527 528 cn->cn_nameiop = nameiop; 529 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 530 cn->cn_lkflags = LK_EXCLUSIVE; 531 cn->cn_thread = td; 532 cn->cn_cred = cnp->cn_cred; 533 534 cn->cn_nameptr = cn->cn_pnbuf; 535 536 if (nameiop == DELETE) 537 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); 538 else if (RENAME == nameiop) 539 cn->cn_flags |= (cnp->cn_flags & SAVESTART); 540 else if (nameiop == CREATE) 541 cn->cn_flags |= NOCACHE; 542 543 vref(dvp); 544 VOP_UNLOCK(dvp, LK_RELEASE); 545 546 if ((error = relookup(dvp, vpp, cn))) { 547 uma_zfree(namei_zone, cn->cn_pnbuf); 548 cn->cn_flags &= ~HASBUF; 549 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 550 } else 551 vrele(dvp); 552 553 return (error); 554 } 555 556 /* 557 * relookup for CREATE namei operation. 558 * 559 * dvp is unionfs vnode. dvp should be locked. 560 * 561 * If it called 'unionfs_copyfile' function by unionfs_link etc, 562 * VOP_LOOKUP information is broken. 563 * So it need relookup in order to create link etc. 564 */ 565 int 566 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 567 struct thread *td) 568 { 569 int error; 570 struct vnode *udvp; 571 struct vnode *vp; 572 struct componentname cn; 573 574 udvp = UNIONFSVPTOUPPERVP(dvp); 575 vp = NULLVP; 576 577 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 578 strlen(cnp->cn_nameptr), CREATE); 579 if (error) 580 return (error); 581 582 if (vp != NULLVP) { 583 if (udvp == vp) 584 vrele(vp); 585 else 586 vput(vp); 587 588 error = EEXIST; 589 } 590 591 if (cn.cn_flags & HASBUF) { 592 uma_zfree(namei_zone, cn.cn_pnbuf); 593 cn.cn_flags &= ~HASBUF; 594 } 595 596 if (!error) { 597 cn.cn_flags |= (cnp->cn_flags & HASBUF); 598 cnp->cn_flags = cn.cn_flags; 599 } 600 601 return (error); 602 } 603 604 /* 605 * relookup for DELETE namei operation. 606 * 607 * dvp is unionfs vnode. dvp should be locked. 608 */ 609 int 610 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 611 struct thread *td) 612 { 613 int error; 614 struct vnode *udvp; 615 struct vnode *vp; 616 struct componentname cn; 617 618 udvp = UNIONFSVPTOUPPERVP(dvp); 619 vp = NULLVP; 620 621 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 622 strlen(cnp->cn_nameptr), DELETE); 623 if (error) 624 return (error); 625 626 if (vp == NULLVP) 627 error = ENOENT; 628 else { 629 if (udvp == vp) 630 vrele(vp); 631 else 632 vput(vp); 633 } 634 635 if (cn.cn_flags & HASBUF) { 636 uma_zfree(namei_zone, cn.cn_pnbuf); 637 cn.cn_flags &= ~HASBUF; 638 } 639 640 if (!error) { 641 cn.cn_flags |= (cnp->cn_flags & HASBUF); 642 cnp->cn_flags = cn.cn_flags; 643 } 644 645 return (error); 646 } 647 648 /* 649 * relookup for RENAME namei operation. 650 * 651 * dvp is unionfs vnode. dvp should be locked. 652 */ 653 int 654 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 655 struct thread *td) 656 { 657 int error; 658 struct vnode *udvp; 659 struct vnode *vp; 660 struct componentname cn; 661 662 udvp = UNIONFSVPTOUPPERVP(dvp); 663 vp = NULLVP; 664 665 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 666 strlen(cnp->cn_nameptr), RENAME); 667 if (error) 668 return (error); 669 670 if (vp != NULLVP) { 671 if (udvp == vp) 672 vrele(vp); 673 else 674 vput(vp); 675 } 676 677 if (cn.cn_flags & HASBUF) { 678 uma_zfree(namei_zone, cn.cn_pnbuf); 679 cn.cn_flags &= ~HASBUF; 680 } 681 682 if (!error) { 683 cn.cn_flags |= (cnp->cn_flags & HASBUF); 684 cnp->cn_flags = cn.cn_flags; 685 } 686 687 return (error); 688 689 } 690 691 /* 692 * Update the unionfs_node. 693 * 694 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 695 * uvp's lock and lower's lock will be unlocked. 696 */ 697 static void 698 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 699 struct thread *td) 700 { 701 unsigned count, lockrec; 702 struct vnode *vp; 703 struct vnode *lvp; 704 struct vnode *dvp; 705 706 vp = UNIONFSTOV(unp); 707 lvp = unp->un_lowervp; 708 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); 709 dvp = unp->un_dvp; 710 711 /* 712 * lock update 713 */ 714 VI_LOCK(vp); 715 unp->un_uppervp = uvp; 716 vp->v_vnlock = uvp->v_vnlock; 717 VI_UNLOCK(vp); 718 lockrec = lvp->v_vnlock->lk_recurse; 719 for (count = 0; count < lockrec; count++) 720 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 721 722 /* 723 * cache update 724 */ 725 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { 726 static struct unionfs_node_hashhead *hd; 727 728 VI_LOCK(dvp); 729 hd = unionfs_get_hashhead(dvp, unp->un_path); 730 LIST_REMOVE(unp, un_hash); 731 LIST_INSERT_HEAD(hd, unp, un_hash); 732 VI_UNLOCK(dvp); 733 } 734 } 735 736 /* 737 * Create a new shadow dir. 738 * 739 * udvp should be locked on entry and will be locked on return. 740 * 741 * If no error returned, unp will be updated. 742 */ 743 int 744 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 745 struct unionfs_node *unp, struct componentname *cnp, 746 struct thread *td) 747 { 748 int error; 749 struct vnode *lvp; 750 struct vnode *uvp; 751 struct vattr va; 752 struct vattr lva; 753 struct componentname cn; 754 struct mount *mp; 755 struct ucred *cred; 756 struct ucred *credbk; 757 struct uidinfo *rootinfo; 758 759 if (unp->un_uppervp != NULLVP) 760 return (EEXIST); 761 762 lvp = unp->un_lowervp; 763 uvp = NULLVP; 764 credbk = cnp->cn_cred; 765 766 /* Authority change to root */ 767 rootinfo = uifind((uid_t)0); 768 cred = crdup(cnp->cn_cred); 769 /* 770 * The calls to chgproccnt() are needed to compensate for change_ruid() 771 * calling chgproccnt(). 772 */ 773 chgproccnt(cred->cr_ruidinfo, 1, 0); 774 change_euid(cred, rootinfo); 775 change_ruid(cred, rootinfo); 776 change_svuid(cred, (uid_t)0); 777 uifree(rootinfo); 778 cnp->cn_cred = cred; 779 780 memset(&cn, 0, sizeof(cn)); 781 782 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 783 goto unionfs_mkshadowdir_abort; 784 785 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 786 goto unionfs_mkshadowdir_abort; 787 if (uvp != NULLVP) { 788 if (udvp == uvp) 789 vrele(uvp); 790 else 791 vput(uvp); 792 793 error = EEXIST; 794 goto unionfs_mkshadowdir_free_out; 795 } 796 797 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) 798 goto unionfs_mkshadowdir_free_out; 799 unionfs_create_uppervattr_core(ump, &lva, &va, td); 800 801 error = VOP_MKDIR(udvp, &uvp, &cn, &va); 802 803 if (!error) { 804 unionfs_node_update(unp, uvp, td); 805 806 /* 807 * XXX The bug which cannot set uid/gid was corrected. 808 * Ignore errors. 809 */ 810 va.va_type = VNON; 811 VOP_SETATTR(uvp, &va, cn.cn_cred); 812 } 813 vn_finished_write(mp); 814 815 unionfs_mkshadowdir_free_out: 816 if (cn.cn_flags & HASBUF) { 817 uma_zfree(namei_zone, cn.cn_pnbuf); 818 cn.cn_flags &= ~HASBUF; 819 } 820 821 unionfs_mkshadowdir_abort: 822 cnp->cn_cred = credbk; 823 chgproccnt(cred->cr_ruidinfo, -1, 0); 824 crfree(cred); 825 826 return (error); 827 } 828 829 /* 830 * Create a new whiteout. 831 * 832 * dvp should be locked on entry and will be locked on return. 833 */ 834 int 835 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 836 struct thread *td, char *path) 837 { 838 int error; 839 struct vnode *wvp; 840 struct componentname cn; 841 struct mount *mp; 842 843 if (path == NULL) 844 path = cnp->cn_nameptr; 845 846 wvp = NULLVP; 847 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) 848 return (error); 849 if (wvp != NULLVP) { 850 if (cn.cn_flags & HASBUF) { 851 uma_zfree(namei_zone, cn.cn_pnbuf); 852 cn.cn_flags &= ~HASBUF; 853 } 854 if (dvp == wvp) 855 vrele(wvp); 856 else 857 vput(wvp); 858 859 return (EEXIST); 860 } 861 862 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) 863 goto unionfs_mkwhiteout_free_out; 864 error = VOP_WHITEOUT(dvp, &cn, CREATE); 865 866 vn_finished_write(mp); 867 868 unionfs_mkwhiteout_free_out: 869 if (cn.cn_flags & HASBUF) { 870 uma_zfree(namei_zone, cn.cn_pnbuf); 871 cn.cn_flags &= ~HASBUF; 872 } 873 874 return (error); 875 } 876 877 /* 878 * Create a new vnode for create a new shadow file. 879 * 880 * If an error is returned, *vpp will be invalid, otherwise it will hold a 881 * locked, referenced and opened vnode. 882 * 883 * unp is never updated. 884 */ 885 static int 886 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 887 struct unionfs_node *unp, struct vattr *uvap, 888 struct thread *td) 889 { 890 struct unionfs_mount *ump; 891 struct vnode *vp; 892 struct vnode *lvp; 893 struct ucred *cred; 894 struct vattr lva; 895 int fmode; 896 int error; 897 struct componentname cn; 898 899 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 900 vp = NULLVP; 901 lvp = unp->un_lowervp; 902 cred = td->td_ucred; 903 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 904 error = 0; 905 906 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 907 return (error); 908 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 909 910 if (unp->un_path == NULL) 911 panic("unionfs: un_path is null"); 912 913 cn.cn_namelen = strlen(unp->un_path); 914 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 915 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); 916 cn.cn_nameiop = CREATE; 917 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 918 cn.cn_lkflags = LK_EXCLUSIVE; 919 cn.cn_thread = td; 920 cn.cn_cred = cred; 921 cn.cn_nameptr = cn.cn_pnbuf; 922 923 vref(udvp); 924 if ((error = relookup(udvp, &vp, &cn)) != 0) 925 goto unionfs_vn_create_on_upper_free_out2; 926 vrele(udvp); 927 928 if (vp != NULLVP) { 929 if (vp == udvp) 930 vrele(vp); 931 else 932 vput(vp); 933 error = EEXIST; 934 goto unionfs_vn_create_on_upper_free_out1; 935 } 936 937 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0) 938 goto unionfs_vn_create_on_upper_free_out1; 939 940 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { 941 vput(vp); 942 goto unionfs_vn_create_on_upper_free_out1; 943 } 944 VOP_ADD_WRITECOUNT(vp, 1); 945 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, 946 vp->v_writecount); 947 *vpp = vp; 948 949 unionfs_vn_create_on_upper_free_out1: 950 VOP_UNLOCK(udvp, LK_RELEASE); 951 952 unionfs_vn_create_on_upper_free_out2: 953 if (cn.cn_flags & HASBUF) { 954 uma_zfree(namei_zone, cn.cn_pnbuf); 955 cn.cn_flags &= ~HASBUF; 956 } 957 958 return (error); 959 } 960 961 /* 962 * Copy from lvp to uvp. 963 * 964 * lvp and uvp should be locked and opened on entry and will be locked and 965 * opened on return. 966 */ 967 static int 968 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, 969 struct ucred *cred, struct thread *td) 970 { 971 int error; 972 off_t offset; 973 int count; 974 int bufoffset; 975 char *buf; 976 struct uio uio; 977 struct iovec iov; 978 979 error = 0; 980 memset(&uio, 0, sizeof(uio)); 981 982 uio.uio_td = td; 983 uio.uio_segflg = UIO_SYSSPACE; 984 uio.uio_offset = 0; 985 986 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); 987 988 while (error == 0) { 989 offset = uio.uio_offset; 990 991 uio.uio_iov = &iov; 992 uio.uio_iovcnt = 1; 993 iov.iov_base = buf; 994 iov.iov_len = MAXBSIZE; 995 uio.uio_resid = iov.iov_len; 996 uio.uio_rw = UIO_READ; 997 998 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) 999 break; 1000 if ((count = MAXBSIZE - uio.uio_resid) == 0) 1001 break; 1002 1003 bufoffset = 0; 1004 while (bufoffset < count) { 1005 uio.uio_iov = &iov; 1006 uio.uio_iovcnt = 1; 1007 iov.iov_base = buf + bufoffset; 1008 iov.iov_len = count - bufoffset; 1009 uio.uio_offset = offset + bufoffset; 1010 uio.uio_resid = iov.iov_len; 1011 uio.uio_rw = UIO_WRITE; 1012 1013 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) 1014 break; 1015 1016 bufoffset += (count - bufoffset) - uio.uio_resid; 1017 } 1018 1019 uio.uio_offset = offset + bufoffset; 1020 } 1021 1022 free(buf, M_TEMP); 1023 1024 return (error); 1025 } 1026 1027 /* 1028 * Copy file from lower to upper. 1029 * 1030 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to 1031 * docopy. 1032 * 1033 * If no error returned, unp will be updated. 1034 */ 1035 int 1036 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, 1037 struct thread *td) 1038 { 1039 int error; 1040 struct mount *mp; 1041 struct vnode *udvp; 1042 struct vnode *lvp; 1043 struct vnode *uvp; 1044 struct vattr uva; 1045 1046 lvp = unp->un_lowervp; 1047 uvp = NULLVP; 1048 1049 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) 1050 return (EROFS); 1051 if (unp->un_dvp == NULLVP) 1052 return (EINVAL); 1053 if (unp->un_uppervp != NULLVP) 1054 return (EEXIST); 1055 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; 1056 if (udvp == NULLVP) 1057 return (EROFS); 1058 if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) 1059 return (EROFS); 1060 1061 error = VOP_ACCESS(lvp, VREAD, cred, td); 1062 if (error != 0) 1063 return (error); 1064 1065 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0) 1066 return (error); 1067 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); 1068 if (error != 0) { 1069 vn_finished_write(mp); 1070 return (error); 1071 } 1072 1073 if (docopy != 0) { 1074 error = VOP_OPEN(lvp, FREAD, cred, td, NULL); 1075 if (error == 0) { 1076 error = unionfs_copyfile_core(lvp, uvp, cred, td); 1077 VOP_CLOSE(lvp, FREAD, cred, td); 1078 } 1079 } 1080 VOP_CLOSE(uvp, FWRITE, cred, td); 1081 VOP_ADD_WRITECOUNT(uvp, -1); 1082 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", __func__, uvp, 1083 uvp->v_writecount); 1084 1085 vn_finished_write(mp); 1086 1087 if (error == 0) { 1088 /* Reset the attributes. Ignore errors. */ 1089 uva.va_type = VNON; 1090 VOP_SETATTR(uvp, &uva, cred); 1091 } 1092 1093 unionfs_node_update(unp, uvp, td); 1094 1095 return (error); 1096 } 1097 1098 /* 1099 * It checks whether vp can rmdir. (check empty) 1100 * 1101 * vp is unionfs vnode. 1102 * vp should be locked. 1103 */ 1104 int 1105 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) 1106 { 1107 int error; 1108 int eofflag; 1109 int lookuperr; 1110 struct vnode *uvp; 1111 struct vnode *lvp; 1112 struct vnode *tvp; 1113 struct vattr va; 1114 struct componentname cn; 1115 /* 1116 * The size of buf needs to be larger than DIRBLKSIZ. 1117 */ 1118 char buf[256 * 6]; 1119 struct dirent *dp; 1120 struct dirent *edp; 1121 struct uio uio; 1122 struct iovec iov; 1123 1124 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir"); 1125 1126 eofflag = 0; 1127 uvp = UNIONFSVPTOUPPERVP(vp); 1128 lvp = UNIONFSVPTOLOWERVP(vp); 1129 1130 /* check opaque */ 1131 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) 1132 return (error); 1133 if (va.va_flags & OPAQUE) 1134 return (0); 1135 1136 /* open vnode */ 1137 #ifdef MAC 1138 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) 1139 return (error); 1140 #endif 1141 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) 1142 return (error); 1143 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) 1144 return (error); 1145 1146 uio.uio_rw = UIO_READ; 1147 uio.uio_segflg = UIO_SYSSPACE; 1148 uio.uio_td = td; 1149 uio.uio_offset = 0; 1150 1151 #ifdef MAC 1152 error = mac_vnode_check_readdir(td->td_ucred, lvp); 1153 #endif 1154 while (!error && !eofflag) { 1155 iov.iov_base = buf; 1156 iov.iov_len = sizeof(buf); 1157 uio.uio_iov = &iov; 1158 uio.uio_iovcnt = 1; 1159 uio.uio_resid = iov.iov_len; 1160 1161 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); 1162 if (error != 0) 1163 break; 1164 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) { 1165 #ifdef DIAGNOSTIC 1166 panic("bad readdir response from lower FS."); 1167 #endif 1168 break; 1169 } 1170 1171 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; 1172 for (dp = (struct dirent*)buf; !error && dp < edp; 1173 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { 1174 if (dp->d_type == DT_WHT || dp->d_fileno == 0 || 1175 (dp->d_namlen == 1 && dp->d_name[0] == '.') || 1176 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) 1177 continue; 1178 1179 cn.cn_namelen = dp->d_namlen; 1180 cn.cn_pnbuf = NULL; 1181 cn.cn_nameptr = dp->d_name; 1182 cn.cn_nameiop = LOOKUP; 1183 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1184 cn.cn_lkflags = LK_EXCLUSIVE; 1185 cn.cn_thread = td; 1186 cn.cn_cred = cred; 1187 1188 /* 1189 * check entry in lower. 1190 * Sometimes, readdir function returns 1191 * wrong entry. 1192 */ 1193 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1194 1195 if (!lookuperr) 1196 vput(tvp); 1197 else 1198 continue; /* skip entry */ 1199 1200 /* 1201 * check entry 1202 * If it has no exist/whiteout entry in upper, 1203 * directory is not empty. 1204 */ 1205 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1206 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1207 1208 if (!lookuperr) 1209 vput(tvp); 1210 1211 /* ignore exist or whiteout entry */ 1212 if (!lookuperr || 1213 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1214 continue; 1215 1216 error = ENOTEMPTY; 1217 } 1218 } 1219 1220 /* close vnode */ 1221 VOP_CLOSE(vp, FREAD, cred, td); 1222 1223 return (error); 1224 } 1225 1226 #ifdef DIAGNOSTIC 1227 1228 struct vnode * 1229 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) 1230 { 1231 struct unionfs_node *unp; 1232 1233 unp = VTOUNIONFS(vp); 1234 1235 #ifdef notyet 1236 if (vp->v_op != unionfs_vnodeop_p) { 1237 printf("unionfs_checkuppervp: on non-unionfs-node.\n"); 1238 #ifdef KDB 1239 kdb_enter(KDB_WHY_UNIONFS, 1240 "unionfs_checkuppervp: on non-unionfs-node.\n"); 1241 #endif 1242 panic("unionfs_checkuppervp"); 1243 } 1244 #endif 1245 return (unp->un_uppervp); 1246 } 1247 1248 struct vnode * 1249 unionfs_checklowervp(struct vnode *vp, char *fil, int lno) 1250 { 1251 struct unionfs_node *unp; 1252 1253 unp = VTOUNIONFS(vp); 1254 1255 #ifdef notyet 1256 if (vp->v_op != unionfs_vnodeop_p) { 1257 printf("unionfs_checklowervp: on non-unionfs-node.\n"); 1258 #ifdef KDB 1259 kdb_enter(KDB_WHY_UNIONFS, 1260 "unionfs_checklowervp: on non-unionfs-node.\n"); 1261 #endif 1262 panic("unionfs_checklowervp"); 1263 } 1264 #endif 1265 return (unp->un_lowervp); 1266 } 1267 #endif
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