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sys/fs/unionfs/union_subr.c
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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: releng/10.4/sys/fs/unionfs/union_subr.c 276500 2015-01-01 10:44:20Z kib $ 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 unp = malloc(sizeof(struct unionfs_node), 251 M_UNIONFSNODE, M_WAITOK | M_ZERO); 252 253 error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp); 254 if (error != 0) { 255 free(unp, M_UNIONFSNODE); 256 return (error); 257 } 258 error = insmntque(vp, mp); /* XXX: Too early for mpsafe fs */ 259 if (error != 0) { 260 free(unp, M_UNIONFSNODE); 261 return (error); 262 } 263 if (dvp != NULLVP) 264 vref(dvp); 265 if (uppervp != NULLVP) 266 vref(uppervp); 267 if (lowervp != NULLVP) 268 vref(lowervp); 269 270 if (vt == VDIR) 271 unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, 272 &(unp->un_hashmask)); 273 274 unp->un_vnode = vp; 275 unp->un_uppervp = uppervp; 276 unp->un_lowervp = lowervp; 277 unp->un_dvp = dvp; 278 if (uppervp != NULLVP) 279 vp->v_vnlock = uppervp->v_vnlock; 280 else 281 vp->v_vnlock = lowervp->v_vnlock; 282 283 if (path != NULL) { 284 unp->un_path = (char *) 285 malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO); 286 bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen); 287 unp->un_path[cnp->cn_namelen] = '\0'; 288 } 289 vp->v_type = vt; 290 vp->v_data = unp; 291 292 if ((uppervp != NULLVP && ump->um_uppervp == uppervp) && 293 (lowervp != NULLVP && ump->um_lowervp == lowervp)) 294 vp->v_vflag |= VV_ROOT; 295 296 if (path != NULL && dvp != NULLVP && vt == VDIR) 297 *vpp = unionfs_ins_cached_vnode(unp, dvp, path); 298 if ((*vpp) != NULLVP) { 299 if (dvp != NULLVP) 300 vrele(dvp); 301 if (uppervp != NULLVP) 302 vrele(uppervp); 303 if (lowervp != NULLVP) 304 vrele(lowervp); 305 306 unp->un_uppervp = NULLVP; 307 unp->un_lowervp = NULLVP; 308 unp->un_dvp = NULLVP; 309 vrele(vp); 310 vp = *vpp; 311 vref(vp); 312 } else 313 *vpp = vp; 314 315 unionfs_nodeget_out: 316 if (lkflags & LK_TYPE_MASK) 317 vn_lock(vp, lkflags | LK_RETRY); 318 319 return (0); 320 } 321 322 /* 323 * Clean up the unionfs node. 324 */ 325 void 326 unionfs_noderem(struct vnode *vp, struct thread *td) 327 { 328 int count; 329 struct unionfs_node *unp, *unp_t1, *unp_t2; 330 struct unionfs_node_hashhead *hd; 331 struct unionfs_node_status *unsp, *unsp_tmp; 332 struct vnode *lvp; 333 struct vnode *uvp; 334 struct vnode *dvp; 335 336 /* 337 * Use the interlock to protect the clearing of v_data to 338 * prevent faults in unionfs_lock(). 339 */ 340 VI_LOCK(vp); 341 unp = VTOUNIONFS(vp); 342 lvp = unp->un_lowervp; 343 uvp = unp->un_uppervp; 344 dvp = unp->un_dvp; 345 unp->un_lowervp = unp->un_uppervp = NULLVP; 346 vp->v_vnlock = &(vp->v_lock); 347 vp->v_data = NULL; 348 vp->v_object = NULL; 349 VI_UNLOCK(vp); 350 351 if (lvp != NULLVP) 352 VOP_UNLOCK(lvp, LK_RELEASE); 353 if (uvp != NULLVP) 354 VOP_UNLOCK(uvp, LK_RELEASE); 355 356 if (dvp != NULLVP && unp->un_hash.le_prev != NULL) 357 unionfs_rem_cached_vnode(unp, dvp); 358 359 if (lockmgr(vp->v_vnlock, LK_EXCLUSIVE, VI_MTX(vp)) != 0) 360 panic("the lock for deletion is unacquirable."); 361 362 if (lvp != NULLVP) 363 vrele(lvp); 364 if (uvp != NULLVP) 365 vrele(uvp); 366 if (dvp != NULLVP) { 367 vrele(dvp); 368 unp->un_dvp = NULLVP; 369 } 370 if (unp->un_path != NULL) { 371 free(unp->un_path, M_UNIONFSPATH); 372 unp->un_path = NULL; 373 } 374 375 if (unp->un_hashtbl != NULL) { 376 for (count = 0; count <= unp->un_hashmask; count++) { 377 hd = unp->un_hashtbl + count; 378 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { 379 LIST_REMOVE(unp_t1, un_hash); 380 unp_t1->un_hash.le_next = NULL; 381 unp_t1->un_hash.le_prev = NULL; 382 } 383 } 384 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask); 385 } 386 387 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { 388 LIST_REMOVE(unsp, uns_list); 389 free(unsp, M_TEMP); 390 } 391 free(unp, M_UNIONFSNODE); 392 } 393 394 /* 395 * Get the unionfs node status. 396 * You need exclusive lock this vnode. 397 */ 398 void 399 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, 400 struct unionfs_node_status **unspp) 401 { 402 struct unionfs_node_status *unsp; 403 pid_t pid = td->td_proc->p_pid; 404 405 KASSERT(NULL != unspp, ("null pointer")); 406 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 407 408 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { 409 if (unsp->uns_pid == pid) { 410 *unspp = unsp; 411 return; 412 } 413 } 414 415 /* create a new unionfs node status */ 416 unsp = malloc(sizeof(struct unionfs_node_status), 417 M_TEMP, M_WAITOK | M_ZERO); 418 419 unsp->uns_pid = pid; 420 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); 421 422 *unspp = unsp; 423 } 424 425 /* 426 * Remove the unionfs node status, if you can. 427 * You need exclusive lock this vnode. 428 */ 429 void 430 unionfs_tryrem_node_status(struct unionfs_node *unp, 431 struct unionfs_node_status *unsp) 432 { 433 KASSERT(NULL != unsp, ("null pointer")); 434 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 435 436 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) 437 return; 438 439 LIST_REMOVE(unsp, uns_list); 440 free(unsp, M_TEMP); 441 } 442 443 /* 444 * Create upper node attr. 445 */ 446 void 447 unionfs_create_uppervattr_core(struct unionfs_mount *ump, 448 struct vattr *lva, 449 struct vattr *uva, 450 struct thread *td) 451 { 452 VATTR_NULL(uva); 453 uva->va_type = lva->va_type; 454 uva->va_atime = lva->va_atime; 455 uva->va_mtime = lva->va_mtime; 456 uva->va_ctime = lva->va_ctime; 457 458 switch (ump->um_copymode) { 459 case UNIONFS_TRANSPARENT: 460 uva->va_mode = lva->va_mode; 461 uva->va_uid = lva->va_uid; 462 uva->va_gid = lva->va_gid; 463 break; 464 case UNIONFS_MASQUERADE: 465 if (ump->um_uid == lva->va_uid) { 466 uva->va_mode = lva->va_mode & 077077; 467 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700; 468 uva->va_uid = lva->va_uid; 469 uva->va_gid = lva->va_gid; 470 } else { 471 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile); 472 uva->va_uid = ump->um_uid; 473 uva->va_gid = ump->um_gid; 474 } 475 break; 476 default: /* UNIONFS_TRADITIONAL */ 477 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask; 478 uva->va_uid = ump->um_uid; 479 uva->va_gid = ump->um_gid; 480 break; 481 } 482 } 483 484 /* 485 * Create upper node attr. 486 */ 487 int 488 unionfs_create_uppervattr(struct unionfs_mount *ump, 489 struct vnode *lvp, 490 struct vattr *uva, 491 struct ucred *cred, 492 struct thread *td) 493 { 494 int error; 495 struct vattr lva; 496 497 if ((error = VOP_GETATTR(lvp, &lva, cred))) 498 return (error); 499 500 unionfs_create_uppervattr_core(ump, &lva, uva, td); 501 502 return (error); 503 } 504 505 /* 506 * relookup 507 * 508 * dvp should be locked on entry and will be locked on return. 509 * 510 * If an error is returned, *vpp will be invalid, otherwise it will hold a 511 * locked, referenced vnode. If *vpp == dvp then remember that only one 512 * LK_EXCLUSIVE lock is held. 513 */ 514 int 515 unionfs_relookup(struct vnode *dvp, struct vnode **vpp, 516 struct componentname *cnp, struct componentname *cn, 517 struct thread *td, char *path, int pathlen, u_long nameiop) 518 { 519 int error; 520 521 cn->cn_namelen = pathlen; 522 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 523 bcopy(path, cn->cn_pnbuf, pathlen); 524 cn->cn_pnbuf[pathlen] = '\0'; 525 526 cn->cn_nameiop = nameiop; 527 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 528 cn->cn_lkflags = LK_EXCLUSIVE; 529 cn->cn_thread = td; 530 cn->cn_cred = cnp->cn_cred; 531 532 cn->cn_nameptr = cn->cn_pnbuf; 533 cn->cn_consume = cnp->cn_consume; 534 535 if (nameiop == DELETE) 536 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); 537 else if (RENAME == nameiop) 538 cn->cn_flags |= (cnp->cn_flags & SAVESTART); 539 else if (nameiop == CREATE) 540 cn->cn_flags |= NOCACHE; 541 542 vref(dvp); 543 VOP_UNLOCK(dvp, LK_RELEASE); 544 545 if ((error = relookup(dvp, vpp, cn))) { 546 uma_zfree(namei_zone, cn->cn_pnbuf); 547 cn->cn_flags &= ~HASBUF; 548 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 549 } else 550 vrele(dvp); 551 552 return (error); 553 } 554 555 /* 556 * relookup for CREATE namei operation. 557 * 558 * dvp is unionfs vnode. dvp should be locked. 559 * 560 * If it called 'unionfs_copyfile' function by unionfs_link etc, 561 * VOP_LOOKUP information is broken. 562 * So it need relookup in order to create link etc. 563 */ 564 int 565 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 566 struct thread *td) 567 { 568 int error; 569 struct vnode *udvp; 570 struct vnode *vp; 571 struct componentname cn; 572 573 udvp = UNIONFSVPTOUPPERVP(dvp); 574 vp = NULLVP; 575 576 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 577 strlen(cnp->cn_nameptr), CREATE); 578 if (error) 579 return (error); 580 581 if (vp != NULLVP) { 582 if (udvp == vp) 583 vrele(vp); 584 else 585 vput(vp); 586 587 error = EEXIST; 588 } 589 590 if (cn.cn_flags & HASBUF) { 591 uma_zfree(namei_zone, cn.cn_pnbuf); 592 cn.cn_flags &= ~HASBUF; 593 } 594 595 if (!error) { 596 cn.cn_flags |= (cnp->cn_flags & HASBUF); 597 cnp->cn_flags = cn.cn_flags; 598 } 599 600 return (error); 601 } 602 603 /* 604 * relookup for DELETE namei operation. 605 * 606 * dvp is unionfs vnode. dvp should be locked. 607 */ 608 int 609 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 610 struct thread *td) 611 { 612 int error; 613 struct vnode *udvp; 614 struct vnode *vp; 615 struct componentname cn; 616 617 udvp = UNIONFSVPTOUPPERVP(dvp); 618 vp = NULLVP; 619 620 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 621 strlen(cnp->cn_nameptr), DELETE); 622 if (error) 623 return (error); 624 625 if (vp == NULLVP) 626 error = ENOENT; 627 else { 628 if (udvp == vp) 629 vrele(vp); 630 else 631 vput(vp); 632 } 633 634 if (cn.cn_flags & HASBUF) { 635 uma_zfree(namei_zone, cn.cn_pnbuf); 636 cn.cn_flags &= ~HASBUF; 637 } 638 639 if (!error) { 640 cn.cn_flags |= (cnp->cn_flags & HASBUF); 641 cnp->cn_flags = cn.cn_flags; 642 } 643 644 return (error); 645 } 646 647 /* 648 * relookup for RENAME namei operation. 649 * 650 * dvp is unionfs vnode. dvp should be locked. 651 */ 652 int 653 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 654 struct thread *td) 655 { 656 int error; 657 struct vnode *udvp; 658 struct vnode *vp; 659 struct componentname cn; 660 661 udvp = UNIONFSVPTOUPPERVP(dvp); 662 vp = NULLVP; 663 664 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 665 strlen(cnp->cn_nameptr), RENAME); 666 if (error) 667 return (error); 668 669 if (vp != NULLVP) { 670 if (udvp == vp) 671 vrele(vp); 672 else 673 vput(vp); 674 } 675 676 if (cn.cn_flags & HASBUF) { 677 uma_zfree(namei_zone, cn.cn_pnbuf); 678 cn.cn_flags &= ~HASBUF; 679 } 680 681 if (!error) { 682 cn.cn_flags |= (cnp->cn_flags & HASBUF); 683 cnp->cn_flags = cn.cn_flags; 684 } 685 686 return (error); 687 688 } 689 690 /* 691 * Update the unionfs_node. 692 * 693 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 694 * uvp's lock and lower's lock will be unlocked. 695 */ 696 static void 697 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 698 struct thread *td) 699 { 700 unsigned count, lockrec; 701 struct vnode *vp; 702 struct vnode *lvp; 703 struct vnode *dvp; 704 705 vp = UNIONFSTOV(unp); 706 lvp = unp->un_lowervp; 707 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); 708 dvp = unp->un_dvp; 709 710 /* 711 * lock update 712 */ 713 VI_LOCK(vp); 714 unp->un_uppervp = uvp; 715 vp->v_vnlock = uvp->v_vnlock; 716 VI_UNLOCK(vp); 717 lockrec = lvp->v_vnlock->lk_recurse; 718 for (count = 0; count < lockrec; count++) 719 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 720 721 /* 722 * cache update 723 */ 724 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { 725 static struct unionfs_node_hashhead *hd; 726 727 VI_LOCK(dvp); 728 hd = unionfs_get_hashhead(dvp, unp->un_path); 729 LIST_REMOVE(unp, un_hash); 730 LIST_INSERT_HEAD(hd, unp, un_hash); 731 VI_UNLOCK(dvp); 732 } 733 } 734 735 /* 736 * Create a new shadow dir. 737 * 738 * udvp should be locked on entry and will be locked on return. 739 * 740 * If no error returned, unp will be updated. 741 */ 742 int 743 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 744 struct unionfs_node *unp, struct componentname *cnp, 745 struct thread *td) 746 { 747 int error; 748 struct vnode *lvp; 749 struct vnode *uvp; 750 struct vattr va; 751 struct vattr lva; 752 struct componentname cn; 753 struct mount *mp; 754 struct ucred *cred; 755 struct ucred *credbk; 756 struct uidinfo *rootinfo; 757 758 if (unp->un_uppervp != NULLVP) 759 return (EEXIST); 760 761 lvp = unp->un_lowervp; 762 uvp = NULLVP; 763 credbk = cnp->cn_cred; 764 765 /* Authority change to root */ 766 rootinfo = uifind((uid_t)0); 767 cred = crdup(cnp->cn_cred); 768 /* 769 * The calls to chgproccnt() are needed to compensate for change_ruid() 770 * calling chgproccnt(). 771 */ 772 chgproccnt(cred->cr_ruidinfo, 1, 0); 773 change_euid(cred, rootinfo); 774 change_ruid(cred, rootinfo); 775 change_svuid(cred, (uid_t)0); 776 uifree(rootinfo); 777 cnp->cn_cred = cred; 778 779 memset(&cn, 0, sizeof(cn)); 780 781 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 782 goto unionfs_mkshadowdir_abort; 783 784 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 785 goto unionfs_mkshadowdir_abort; 786 if (uvp != NULLVP) { 787 if (udvp == uvp) 788 vrele(uvp); 789 else 790 vput(uvp); 791 792 error = EEXIST; 793 goto unionfs_mkshadowdir_free_out; 794 } 795 796 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) 797 goto unionfs_mkshadowdir_free_out; 798 unionfs_create_uppervattr_core(ump, &lva, &va, td); 799 800 error = VOP_MKDIR(udvp, &uvp, &cn, &va); 801 802 if (!error) { 803 unionfs_node_update(unp, uvp, td); 804 805 /* 806 * XXX The bug which cannot set uid/gid was corrected. 807 * Ignore errors. 808 */ 809 va.va_type = VNON; 810 VOP_SETATTR(uvp, &va, cn.cn_cred); 811 } 812 vn_finished_write(mp); 813 814 unionfs_mkshadowdir_free_out: 815 if (cn.cn_flags & HASBUF) { 816 uma_zfree(namei_zone, cn.cn_pnbuf); 817 cn.cn_flags &= ~HASBUF; 818 } 819 820 unionfs_mkshadowdir_abort: 821 cnp->cn_cred = credbk; 822 chgproccnt(cred->cr_ruidinfo, -1, 0); 823 crfree(cred); 824 825 return (error); 826 } 827 828 /* 829 * Create a new whiteout. 830 * 831 * dvp should be locked on entry and will be locked on return. 832 */ 833 int 834 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 835 struct thread *td, char *path) 836 { 837 int error; 838 struct vnode *wvp; 839 struct componentname cn; 840 struct mount *mp; 841 842 if (path == NULL) 843 path = cnp->cn_nameptr; 844 845 wvp = NULLVP; 846 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) 847 return (error); 848 if (wvp != NULLVP) { 849 if (cn.cn_flags & HASBUF) { 850 uma_zfree(namei_zone, cn.cn_pnbuf); 851 cn.cn_flags &= ~HASBUF; 852 } 853 if (dvp == wvp) 854 vrele(wvp); 855 else 856 vput(wvp); 857 858 return (EEXIST); 859 } 860 861 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) 862 goto unionfs_mkwhiteout_free_out; 863 error = VOP_WHITEOUT(dvp, &cn, CREATE); 864 865 vn_finished_write(mp); 866 867 unionfs_mkwhiteout_free_out: 868 if (cn.cn_flags & HASBUF) { 869 uma_zfree(namei_zone, cn.cn_pnbuf); 870 cn.cn_flags &= ~HASBUF; 871 } 872 873 return (error); 874 } 875 876 /* 877 * Create a new vnode for create a new shadow file. 878 * 879 * If an error is returned, *vpp will be invalid, otherwise it will hold a 880 * locked, referenced and opened vnode. 881 * 882 * unp is never updated. 883 */ 884 static int 885 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 886 struct unionfs_node *unp, struct vattr *uvap, 887 struct thread *td) 888 { 889 struct unionfs_mount *ump; 890 struct vnode *vp; 891 struct vnode *lvp; 892 struct ucred *cred; 893 struct vattr lva; 894 int fmode; 895 int error; 896 struct componentname cn; 897 898 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 899 vp = NULLVP; 900 lvp = unp->un_lowervp; 901 cred = td->td_ucred; 902 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 903 error = 0; 904 905 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 906 return (error); 907 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 908 909 if (unp->un_path == NULL) 910 panic("unionfs: un_path is null"); 911 912 cn.cn_namelen = strlen(unp->un_path); 913 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 914 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); 915 cn.cn_nameiop = CREATE; 916 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 917 cn.cn_lkflags = LK_EXCLUSIVE; 918 cn.cn_thread = td; 919 cn.cn_cred = cred; 920 cn.cn_nameptr = cn.cn_pnbuf; 921 cn.cn_consume = 0; 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 cn.cn_consume = 0; 1188 1189 /* 1190 * check entry in lower. 1191 * Sometimes, readdir function returns 1192 * wrong entry. 1193 */ 1194 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1195 1196 if (!lookuperr) 1197 vput(tvp); 1198 else 1199 continue; /* skip entry */ 1200 1201 /* 1202 * check entry 1203 * If it has no exist/whiteout entry in upper, 1204 * directory is not empty. 1205 */ 1206 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1207 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1208 1209 if (!lookuperr) 1210 vput(tvp); 1211 1212 /* ignore exist or whiteout entry */ 1213 if (!lookuperr || 1214 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1215 continue; 1216 1217 error = ENOTEMPTY; 1218 } 1219 } 1220 1221 /* close vnode */ 1222 VOP_CLOSE(vp, FREAD, cred, td); 1223 1224 return (error); 1225 } 1226 1227 #ifdef DIAGNOSTIC 1228 1229 struct vnode * 1230 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) 1231 { 1232 struct unionfs_node *unp; 1233 1234 unp = VTOUNIONFS(vp); 1235 1236 #ifdef notyet 1237 if (vp->v_op != unionfs_vnodeop_p) { 1238 printf("unionfs_checkuppervp: on non-unionfs-node.\n"); 1239 #ifdef KDB 1240 kdb_enter(KDB_WHY_UNIONFS, 1241 "unionfs_checkuppervp: on non-unionfs-node.\n"); 1242 #endif 1243 panic("unionfs_checkuppervp"); 1244 }; 1245 #endif 1246 return (unp->un_uppervp); 1247 } 1248 1249 struct vnode * 1250 unionfs_checklowervp(struct vnode *vp, char *fil, int lno) 1251 { 1252 struct unionfs_node *unp; 1253 1254 unp = VTOUNIONFS(vp); 1255 1256 #ifdef notyet 1257 if (vp->v_op != unionfs_vnodeop_p) { 1258 printf("unionfs_checklowervp: on non-unionfs-node.\n"); 1259 #ifdef KDB 1260 kdb_enter(KDB_WHY_UNIONFS, 1261 "unionfs_checklowervp: on non-unionfs-node.\n"); 1262 #endif 1263 panic("unionfs_checklowervp"); 1264 }; 1265 #endif 1266 return (unp->un_lowervp); 1267 } 1268 #endif
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