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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/8.4/sys/fs/unionfs/union_subr.c 235244 2012-05-10 20:37:56Z daichi $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/malloc.h> 45 #include <sys/mount.h> 46 #include <sys/namei.h> 47 #include <sys/proc.h> 48 #include <sys/vnode.h> 49 #include <sys/dirent.h> 50 #include <sys/fcntl.h> 51 #include <sys/filedesc.h> 52 #include <sys/stat.h> 53 #include <sys/resourcevar.h> 54 55 #include <security/mac/mac_framework.h> 56 57 #include <vm/uma.h> 58 59 #include <fs/unionfs/union.h> 60 61 #define NUNIONFSNODECACHE 16 62 63 static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table"); 64 MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part"); 65 MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part"); 66 67 /* 68 * Initialize 69 */ 70 int 71 unionfs_init(struct vfsconf *vfsp) 72 { 73 UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */ 74 return (0); 75 } 76 77 /* 78 * Uninitialize 79 */ 80 int 81 unionfs_uninit(struct vfsconf *vfsp) 82 { 83 return (0); 84 } 85 86 static struct unionfs_node_hashhead * 87 unionfs_get_hashhead(struct vnode *dvp, char *path) 88 { 89 int count; 90 char hash; 91 struct unionfs_node *unp; 92 93 hash = 0; 94 unp = VTOUNIONFS(dvp); 95 if (path != NULL) { 96 for (count = 0; path[count]; count++) 97 hash += path[count]; 98 } 99 100 return (&(unp->un_hashtbl[hash & (unp->un_hashmask)])); 101 } 102 103 /* 104 * Get the cached vnode. 105 */ 106 static struct vnode * 107 unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp, 108 struct vnode *dvp, char *path) 109 { 110 struct unionfs_node_hashhead *hd; 111 struct unionfs_node *unp; 112 struct vnode *vp; 113 114 KASSERT((uvp == NULLVP || uvp->v_type == VDIR), 115 ("unionfs_get_cached_vnode: v_type != VDIR")); 116 KASSERT((lvp == NULLVP || lvp->v_type == VDIR), 117 ("unionfs_get_cached_vnode: v_type != VDIR")); 118 119 VI_LOCK(dvp); 120 hd = unionfs_get_hashhead(dvp, path); 121 LIST_FOREACH(unp, hd, un_hash) { 122 if (!strcmp(unp->un_path, path)) { 123 vp = UNIONFSTOV(unp); 124 VI_LOCK_FLAGS(vp, MTX_DUPOK); 125 VI_UNLOCK(dvp); 126 vp->v_iflag &= ~VI_OWEINACT; 127 if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) { 128 VI_UNLOCK(vp); 129 vp = NULLVP; 130 } else 131 VI_UNLOCK(vp); 132 return (vp); 133 } 134 } 135 VI_UNLOCK(dvp); 136 137 return (NULLVP); 138 } 139 140 /* 141 * Add the new vnode into cache. 142 */ 143 static struct vnode * 144 unionfs_ins_cached_vnode(struct unionfs_node *uncp, 145 struct vnode *dvp, char *path) 146 { 147 struct unionfs_node_hashhead *hd; 148 struct unionfs_node *unp; 149 struct vnode *vp; 150 151 KASSERT((uncp->un_uppervp==NULLVP || uncp->un_uppervp->v_type==VDIR), 152 ("unionfs_ins_cached_vnode: v_type != VDIR")); 153 KASSERT((uncp->un_lowervp==NULLVP || uncp->un_lowervp->v_type==VDIR), 154 ("unionfs_ins_cached_vnode: v_type != VDIR")); 155 156 VI_LOCK(dvp); 157 hd = unionfs_get_hashhead(dvp, path); 158 LIST_FOREACH(unp, hd, un_hash) { 159 if (!strcmp(unp->un_path, path)) { 160 vp = UNIONFSTOV(unp); 161 VI_LOCK_FLAGS(vp, MTX_DUPOK); 162 vp->v_iflag &= ~VI_OWEINACT; 163 if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) { 164 LIST_INSERT_HEAD(hd, uncp, un_hash); 165 VI_UNLOCK(vp); 166 vp = NULLVP; 167 } else 168 VI_UNLOCK(vp); 169 VI_UNLOCK(dvp); 170 return (vp); 171 } 172 } 173 174 LIST_INSERT_HEAD(hd, uncp, un_hash); 175 VI_UNLOCK(dvp); 176 177 return (NULLVP); 178 } 179 180 /* 181 * Remove the vnode. 182 */ 183 static void 184 unionfs_rem_cached_vnode(struct unionfs_node *unp, struct vnode *dvp) 185 { 186 KASSERT((unp != NULL), ("unionfs_rem_cached_vnode: null node")); 187 KASSERT((dvp != NULLVP), 188 ("unionfs_rem_cached_vnode: null parent vnode")); 189 KASSERT((unp->un_hash.le_prev != NULL), 190 ("unionfs_rem_cached_vnode: null hash")); 191 192 VI_LOCK(dvp); 193 LIST_REMOVE(unp, un_hash); 194 unp->un_hash.le_next = NULL; 195 unp->un_hash.le_prev = NULL; 196 VI_UNLOCK(dvp); 197 } 198 199 /* 200 * Make a new or get existing unionfs node. 201 * 202 * uppervp and lowervp should be unlocked. Because if new unionfs vnode is 203 * locked, uppervp or lowervp is locked too. In order to prevent dead lock, 204 * you should not lock plurality simultaneously. 205 */ 206 int 207 unionfs_nodeget(struct mount *mp, struct vnode *uppervp, 208 struct vnode *lowervp, struct vnode *dvp, 209 struct vnode **vpp, struct componentname *cnp, 210 struct thread *td) 211 { 212 struct unionfs_mount *ump; 213 struct unionfs_node *unp; 214 struct vnode *vp; 215 int error; 216 int lkflags; 217 enum vtype vt; 218 char *path; 219 220 ump = MOUNTTOUNIONFSMOUNT(mp); 221 lkflags = (cnp ? cnp->cn_lkflags : 0); 222 path = (cnp ? cnp->cn_nameptr : NULL); 223 *vpp = NULLVP; 224 225 if (uppervp == NULLVP && lowervp == NULLVP) 226 panic("unionfs_nodeget: upper and lower is null"); 227 228 vt = (uppervp != NULLVP ? uppervp->v_type : lowervp->v_type); 229 230 /* If it has no ISLASTCN flag, path check is skipped. */ 231 if (cnp && !(cnp->cn_flags & ISLASTCN)) 232 path = NULL; 233 234 /* check the cache */ 235 if (path != NULL && dvp != NULLVP && vt == VDIR) { 236 vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp, path); 237 if (vp != NULLVP) { 238 vref(vp); 239 *vpp = vp; 240 goto unionfs_nodeget_out; 241 } 242 } 243 244 if ((uppervp == NULLVP || ump->um_uppervp != uppervp) || 245 (lowervp == NULLVP || ump->um_lowervp != lowervp)) { 246 /* dvp will be NULLVP only in case of root vnode. */ 247 if (dvp == NULLVP) 248 return (EINVAL); 249 } 250 251 /* 252 * Do the MALLOC before the getnewvnode since doing so afterward 253 * might cause a bogus v_data pointer to get dereferenced elsewhere 254 * if MALLOC should block. 255 */ 256 unp = malloc(sizeof(struct unionfs_node), 257 M_UNIONFSNODE, M_WAITOK | M_ZERO); 258 259 error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp); 260 if (error != 0) { 261 free(unp, M_UNIONFSNODE); 262 return (error); 263 } 264 error = insmntque(vp, mp); /* XXX: Too early for mpsafe fs */ 265 if (error != 0) { 266 free(unp, M_UNIONFSNODE); 267 return (error); 268 } 269 if (dvp != NULLVP) 270 vref(dvp); 271 if (uppervp != NULLVP) 272 vref(uppervp); 273 if (lowervp != NULLVP) 274 vref(lowervp); 275 276 if (vt == VDIR) 277 unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH, 278 &(unp->un_hashmask)); 279 280 unp->un_vnode = vp; 281 unp->un_uppervp = uppervp; 282 unp->un_lowervp = lowervp; 283 unp->un_dvp = dvp; 284 if (uppervp != NULLVP) 285 vp->v_vnlock = uppervp->v_vnlock; 286 else 287 vp->v_vnlock = lowervp->v_vnlock; 288 289 if (path != NULL) { 290 unp->un_path = (char *) 291 malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO); 292 bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen); 293 unp->un_path[cnp->cn_namelen] = '\0'; 294 } 295 vp->v_type = vt; 296 vp->v_data = unp; 297 298 if ((uppervp != NULLVP && ump->um_uppervp == uppervp) && 299 (lowervp != NULLVP && ump->um_lowervp == lowervp)) 300 vp->v_vflag |= VV_ROOT; 301 302 if (path != NULL && dvp != NULLVP && vt == VDIR) 303 *vpp = unionfs_ins_cached_vnode(unp, dvp, path); 304 if ((*vpp) != NULLVP) { 305 if (dvp != NULLVP) 306 vrele(dvp); 307 if (uppervp != NULLVP) 308 vrele(uppervp); 309 if (lowervp != NULLVP) 310 vrele(lowervp); 311 312 unp->un_uppervp = NULLVP; 313 unp->un_lowervp = NULLVP; 314 unp->un_dvp = NULLVP; 315 vrele(vp); 316 vp = *vpp; 317 vref(vp); 318 } else 319 *vpp = vp; 320 321 unionfs_nodeget_out: 322 if (lkflags & LK_TYPE_MASK) 323 vn_lock(vp, lkflags | LK_RETRY); 324 325 return (0); 326 } 327 328 /* 329 * Clean up the unionfs node. 330 */ 331 void 332 unionfs_noderem(struct vnode *vp, struct thread *td) 333 { 334 int vfslocked; 335 int count; 336 struct unionfs_node *unp, *unp_t1, *unp_t2; 337 struct unionfs_node_hashhead *hd; 338 struct unionfs_node_status *unsp, *unsp_tmp; 339 struct vnode *lvp; 340 struct vnode *uvp; 341 struct vnode *dvp; 342 343 /* 344 * Use the interlock to protect the clearing of v_data to 345 * prevent faults in unionfs_lock(). 346 */ 347 VI_LOCK(vp); 348 unp = VTOUNIONFS(vp); 349 lvp = unp->un_lowervp; 350 uvp = unp->un_uppervp; 351 dvp = unp->un_dvp; 352 unp->un_lowervp = unp->un_uppervp = NULLVP; 353 vp->v_vnlock = &(vp->v_lock); 354 vp->v_data = NULL; 355 vp->v_object = NULL; 356 VI_UNLOCK(vp); 357 358 if (lvp != NULLVP) 359 VOP_UNLOCK(lvp, LK_RELEASE); 360 if (uvp != NULLVP) 361 VOP_UNLOCK(uvp, LK_RELEASE); 362 363 if (dvp != NULLVP && unp->un_hash.le_prev != NULL) 364 unionfs_rem_cached_vnode(unp, dvp); 365 366 if (lockmgr(vp->v_vnlock, LK_EXCLUSIVE, VI_MTX(vp)) != 0) 367 panic("the lock for deletion is unacquirable."); 368 369 if (lvp != NULLVP) { 370 vfslocked = VFS_LOCK_GIANT(lvp->v_mount); 371 vrele(lvp); 372 VFS_UNLOCK_GIANT(vfslocked); 373 } 374 if (uvp != NULLVP) { 375 vfslocked = VFS_LOCK_GIANT(uvp->v_mount); 376 vrele(uvp); 377 VFS_UNLOCK_GIANT(vfslocked); 378 } 379 if (dvp != NULLVP) { 380 vfslocked = VFS_LOCK_GIANT(dvp->v_mount); 381 vrele(dvp); 382 VFS_UNLOCK_GIANT(vfslocked); 383 unp->un_dvp = NULLVP; 384 } 385 if (unp->un_path != NULL) { 386 free(unp->un_path, M_UNIONFSPATH); 387 unp->un_path = NULL; 388 } 389 390 if (unp->un_hashtbl != NULL) { 391 for (count = 0; count <= unp->un_hashmask; count++) { 392 hd = unp->un_hashtbl + count; 393 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { 394 LIST_REMOVE(unp_t1, un_hash); 395 unp_t1->un_hash.le_next = NULL; 396 unp_t1->un_hash.le_prev = NULL; 397 } 398 } 399 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask); 400 } 401 402 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { 403 LIST_REMOVE(unsp, uns_list); 404 free(unsp, M_TEMP); 405 } 406 free(unp, M_UNIONFSNODE); 407 } 408 409 /* 410 * Get the unionfs node status. 411 * You need exclusive lock this vnode. 412 */ 413 void 414 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, 415 struct unionfs_node_status **unspp) 416 { 417 struct unionfs_node_status *unsp; 418 pid_t pid = td->td_proc->p_pid; 419 420 KASSERT(NULL != unspp, ("null pointer")); 421 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 422 423 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { 424 if (unsp->uns_pid == pid) { 425 *unspp = unsp; 426 return; 427 } 428 } 429 430 /* create a new unionfs node status */ 431 unsp = malloc(sizeof(struct unionfs_node_status), 432 M_TEMP, M_WAITOK | M_ZERO); 433 434 unsp->uns_pid = pid; 435 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); 436 437 *unspp = unsp; 438 } 439 440 /* 441 * Remove the unionfs node status, if you can. 442 * You need exclusive lock this vnode. 443 */ 444 void 445 unionfs_tryrem_node_status(struct unionfs_node *unp, 446 struct unionfs_node_status *unsp) 447 { 448 KASSERT(NULL != unsp, ("null pointer")); 449 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 450 451 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) 452 return; 453 454 LIST_REMOVE(unsp, uns_list); 455 free(unsp, M_TEMP); 456 } 457 458 /* 459 * Create upper node attr. 460 */ 461 void 462 unionfs_create_uppervattr_core(struct unionfs_mount *ump, 463 struct vattr *lva, 464 struct vattr *uva, 465 struct thread *td) 466 { 467 VATTR_NULL(uva); 468 uva->va_type = lva->va_type; 469 uva->va_atime = lva->va_atime; 470 uva->va_mtime = lva->va_mtime; 471 uva->va_ctime = lva->va_ctime; 472 473 switch (ump->um_copymode) { 474 case UNIONFS_TRANSPARENT: 475 uva->va_mode = lva->va_mode; 476 uva->va_uid = lva->va_uid; 477 uva->va_gid = lva->va_gid; 478 break; 479 case UNIONFS_MASQUERADE: 480 if (ump->um_uid == lva->va_uid) { 481 uva->va_mode = lva->va_mode & 077077; 482 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700; 483 uva->va_uid = lva->va_uid; 484 uva->va_gid = lva->va_gid; 485 } else { 486 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile); 487 uva->va_uid = ump->um_uid; 488 uva->va_gid = ump->um_gid; 489 } 490 break; 491 default: /* UNIONFS_TRADITIONAL */ 492 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask; 493 uva->va_uid = ump->um_uid; 494 uva->va_gid = ump->um_gid; 495 break; 496 } 497 } 498 499 /* 500 * Create upper node attr. 501 */ 502 int 503 unionfs_create_uppervattr(struct unionfs_mount *ump, 504 struct vnode *lvp, 505 struct vattr *uva, 506 struct ucred *cred, 507 struct thread *td) 508 { 509 int error; 510 struct vattr lva; 511 512 if ((error = VOP_GETATTR(lvp, &lva, cred))) 513 return (error); 514 515 unionfs_create_uppervattr_core(ump, &lva, uva, td); 516 517 return (error); 518 } 519 520 /* 521 * relookup 522 * 523 * dvp should be locked on entry and will be locked on return. 524 * 525 * If an error is returned, *vpp will be invalid, otherwise it will hold a 526 * locked, referenced vnode. If *vpp == dvp then remember that only one 527 * LK_EXCLUSIVE lock is held. 528 */ 529 int 530 unionfs_relookup(struct vnode *dvp, struct vnode **vpp, 531 struct componentname *cnp, struct componentname *cn, 532 struct thread *td, char *path, int pathlen, u_long nameiop) 533 { 534 int error; 535 536 cn->cn_namelen = pathlen; 537 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 538 bcopy(path, cn->cn_pnbuf, pathlen); 539 cn->cn_pnbuf[pathlen] = '\0'; 540 541 cn->cn_nameiop = nameiop; 542 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 543 cn->cn_lkflags = LK_EXCLUSIVE; 544 cn->cn_thread = td; 545 cn->cn_cred = cnp->cn_cred; 546 547 cn->cn_nameptr = cn->cn_pnbuf; 548 cn->cn_consume = cnp->cn_consume; 549 550 if (nameiop == DELETE) 551 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); 552 else if (RENAME == nameiop) 553 cn->cn_flags |= (cnp->cn_flags & SAVESTART); 554 555 vref(dvp); 556 VOP_UNLOCK(dvp, LK_RELEASE); 557 558 if ((error = relookup(dvp, vpp, cn))) { 559 uma_zfree(namei_zone, cn->cn_pnbuf); 560 cn->cn_flags &= ~HASBUF; 561 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 562 } else 563 vrele(dvp); 564 565 return (error); 566 } 567 568 /* 569 * relookup for CREATE namei operation. 570 * 571 * dvp is unionfs vnode. dvp should be locked. 572 * 573 * If it called 'unionfs_copyfile' function by unionfs_link etc, 574 * VOP_LOOKUP information is broken. 575 * So it need relookup in order to create link etc. 576 */ 577 int 578 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 579 struct thread *td) 580 { 581 int error; 582 struct vnode *udvp; 583 struct vnode *vp; 584 struct componentname cn; 585 586 udvp = UNIONFSVPTOUPPERVP(dvp); 587 vp = NULLVP; 588 589 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 590 strlen(cnp->cn_nameptr), CREATE); 591 if (error) 592 return (error); 593 594 if (vp != NULLVP) { 595 if (udvp == vp) 596 vrele(vp); 597 else 598 vput(vp); 599 600 error = EEXIST; 601 } 602 603 if (cn.cn_flags & HASBUF) { 604 uma_zfree(namei_zone, cn.cn_pnbuf); 605 cn.cn_flags &= ~HASBUF; 606 } 607 608 if (!error) { 609 cn.cn_flags |= (cnp->cn_flags & HASBUF); 610 cnp->cn_flags = cn.cn_flags; 611 } 612 613 return (error); 614 } 615 616 /* 617 * relookup for DELETE namei operation. 618 * 619 * dvp is unionfs vnode. dvp should be locked. 620 */ 621 int 622 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 623 struct thread *td) 624 { 625 int error; 626 struct vnode *udvp; 627 struct vnode *vp; 628 struct componentname cn; 629 630 udvp = UNIONFSVPTOUPPERVP(dvp); 631 vp = NULLVP; 632 633 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 634 strlen(cnp->cn_nameptr), DELETE); 635 if (error) 636 return (error); 637 638 if (vp == NULLVP) 639 error = ENOENT; 640 else { 641 if (udvp == vp) 642 vrele(vp); 643 else 644 vput(vp); 645 } 646 647 if (cn.cn_flags & HASBUF) { 648 uma_zfree(namei_zone, cn.cn_pnbuf); 649 cn.cn_flags &= ~HASBUF; 650 } 651 652 if (!error) { 653 cn.cn_flags |= (cnp->cn_flags & HASBUF); 654 cnp->cn_flags = cn.cn_flags; 655 } 656 657 return (error); 658 } 659 660 /* 661 * relookup for RENAME namei operation. 662 * 663 * dvp is unionfs vnode. dvp should be locked. 664 */ 665 int 666 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 667 struct thread *td) 668 { 669 int error; 670 struct vnode *udvp; 671 struct vnode *vp; 672 struct componentname cn; 673 674 udvp = UNIONFSVPTOUPPERVP(dvp); 675 vp = NULLVP; 676 677 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 678 strlen(cnp->cn_nameptr), RENAME); 679 if (error) 680 return (error); 681 682 if (vp != NULLVP) { 683 if (udvp == vp) 684 vrele(vp); 685 else 686 vput(vp); 687 } 688 689 if (cn.cn_flags & HASBUF) { 690 uma_zfree(namei_zone, cn.cn_pnbuf); 691 cn.cn_flags &= ~HASBUF; 692 } 693 694 if (!error) { 695 cn.cn_flags |= (cnp->cn_flags & HASBUF); 696 cnp->cn_flags = cn.cn_flags; 697 } 698 699 return (error); 700 701 } 702 703 /* 704 * Update the unionfs_node. 705 * 706 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 707 * uvp's lock and lower's lock will be unlocked. 708 */ 709 static void 710 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 711 struct thread *td) 712 { 713 unsigned count, lockrec; 714 struct vnode *vp; 715 struct vnode *lvp; 716 struct vnode *dvp; 717 718 vp = UNIONFSTOV(unp); 719 lvp = unp->un_lowervp; 720 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); 721 dvp = unp->un_dvp; 722 723 /* 724 * lock update 725 */ 726 VI_LOCK(vp); 727 unp->un_uppervp = uvp; 728 vp->v_vnlock = uvp->v_vnlock; 729 VI_UNLOCK(vp); 730 lockrec = lvp->v_vnlock->lk_recurse; 731 for (count = 0; count < lockrec; count++) 732 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 733 734 /* 735 * cache update 736 */ 737 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { 738 static struct unionfs_node_hashhead *hd; 739 740 VI_LOCK(dvp); 741 hd = unionfs_get_hashhead(dvp, unp->un_path); 742 LIST_REMOVE(unp, un_hash); 743 LIST_INSERT_HEAD(hd, unp, un_hash); 744 VI_UNLOCK(dvp); 745 } 746 } 747 748 /* 749 * Create a new shadow dir. 750 * 751 * udvp should be locked on entry and will be locked on return. 752 * 753 * If no error returned, unp will be updated. 754 */ 755 int 756 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 757 struct unionfs_node *unp, struct componentname *cnp, 758 struct thread *td) 759 { 760 int error; 761 struct vnode *lvp; 762 struct vnode *uvp; 763 struct vattr va; 764 struct vattr lva; 765 struct componentname cn; 766 struct mount *mp; 767 struct ucred *cred; 768 struct ucred *credbk; 769 struct uidinfo *rootinfo; 770 771 if (unp->un_uppervp != NULLVP) 772 return (EEXIST); 773 774 lvp = unp->un_lowervp; 775 uvp = NULLVP; 776 credbk = cnp->cn_cred; 777 778 /* Authority change to root */ 779 rootinfo = uifind((uid_t)0); 780 cred = crdup(cnp->cn_cred); 781 chgproccnt(cred->cr_ruidinfo, 1, 0); 782 change_euid(cred, rootinfo); 783 change_ruid(cred, rootinfo); 784 change_svuid(cred, (uid_t)0); 785 uifree(rootinfo); 786 cnp->cn_cred = cred; 787 788 memset(&cn, 0, sizeof(cn)); 789 790 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 791 goto unionfs_mkshadowdir_abort; 792 793 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 794 goto unionfs_mkshadowdir_abort; 795 if (uvp != NULLVP) { 796 if (udvp == uvp) 797 vrele(uvp); 798 else 799 vput(uvp); 800 801 error = EEXIST; 802 goto unionfs_mkshadowdir_free_out; 803 } 804 805 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) 806 goto unionfs_mkshadowdir_free_out; 807 unionfs_create_uppervattr_core(ump, &lva, &va, td); 808 809 error = VOP_MKDIR(udvp, &uvp, &cn, &va); 810 811 if (!error) { 812 unionfs_node_update(unp, uvp, td); 813 814 /* 815 * XXX The bug which cannot set uid/gid was corrected. 816 * Ignore errors. 817 */ 818 va.va_type = VNON; 819 VOP_SETATTR(uvp, &va, cn.cn_cred); 820 } 821 vn_finished_write(mp); 822 823 unionfs_mkshadowdir_free_out: 824 if (cn.cn_flags & HASBUF) { 825 uma_zfree(namei_zone, cn.cn_pnbuf); 826 cn.cn_flags &= ~HASBUF; 827 } 828 829 unionfs_mkshadowdir_abort: 830 cnp->cn_cred = credbk; 831 chgproccnt(cred->cr_ruidinfo, -1, 0); 832 crfree(cred); 833 834 return (error); 835 } 836 837 /* 838 * Create a new whiteout. 839 * 840 * dvp should be locked on entry and will be locked on return. 841 */ 842 int 843 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 844 struct thread *td, char *path) 845 { 846 int error; 847 struct vnode *wvp; 848 struct componentname cn; 849 struct mount *mp; 850 851 if (path == NULL) 852 path = cnp->cn_nameptr; 853 854 wvp = NULLVP; 855 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) 856 return (error); 857 if (wvp != NULLVP) { 858 if (cn.cn_flags & HASBUF) { 859 uma_zfree(namei_zone, cn.cn_pnbuf); 860 cn.cn_flags &= ~HASBUF; 861 } 862 if (dvp == wvp) 863 vrele(wvp); 864 else 865 vput(wvp); 866 867 return (EEXIST); 868 } 869 870 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) 871 goto unionfs_mkwhiteout_free_out; 872 error = VOP_WHITEOUT(dvp, &cn, CREATE); 873 874 vn_finished_write(mp); 875 876 unionfs_mkwhiteout_free_out: 877 if (cn.cn_flags & HASBUF) { 878 uma_zfree(namei_zone, cn.cn_pnbuf); 879 cn.cn_flags &= ~HASBUF; 880 } 881 882 return (error); 883 } 884 885 /* 886 * Create a new vnode for create a new shadow file. 887 * 888 * If an error is returned, *vpp will be invalid, otherwise it will hold a 889 * locked, referenced and opened vnode. 890 * 891 * unp is never updated. 892 */ 893 static int 894 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 895 struct unionfs_node *unp, struct vattr *uvap, 896 struct thread *td) 897 { 898 struct unionfs_mount *ump; 899 struct vnode *vp; 900 struct vnode *lvp; 901 struct ucred *cred; 902 struct vattr lva; 903 int fmode; 904 int error; 905 struct componentname cn; 906 907 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 908 vp = NULLVP; 909 lvp = unp->un_lowervp; 910 cred = td->td_ucred; 911 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 912 error = 0; 913 914 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 915 return (error); 916 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 917 918 if (unp->un_path == NULL) 919 panic("unionfs: un_path is null"); 920 921 cn.cn_namelen = strlen(unp->un_path); 922 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 923 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); 924 cn.cn_nameiop = CREATE; 925 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 926 cn.cn_lkflags = LK_EXCLUSIVE; 927 cn.cn_thread = td; 928 cn.cn_cred = cred; 929 cn.cn_nameptr = cn.cn_pnbuf; 930 cn.cn_consume = 0; 931 932 vref(udvp); 933 if ((error = relookup(udvp, &vp, &cn)) != 0) 934 goto unionfs_vn_create_on_upper_free_out2; 935 vrele(udvp); 936 937 if (vp != NULLVP) { 938 if (vp == udvp) 939 vrele(vp); 940 else 941 vput(vp); 942 error = EEXIST; 943 goto unionfs_vn_create_on_upper_free_out1; 944 } 945 946 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0) 947 goto unionfs_vn_create_on_upper_free_out1; 948 949 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { 950 vput(vp); 951 goto unionfs_vn_create_on_upper_free_out1; 952 } 953 vp->v_writecount++; 954 *vpp = vp; 955 956 unionfs_vn_create_on_upper_free_out1: 957 VOP_UNLOCK(udvp, LK_RELEASE); 958 959 unionfs_vn_create_on_upper_free_out2: 960 if (cn.cn_flags & HASBUF) { 961 uma_zfree(namei_zone, cn.cn_pnbuf); 962 cn.cn_flags &= ~HASBUF; 963 } 964 965 return (error); 966 } 967 968 /* 969 * Copy from lvp to uvp. 970 * 971 * lvp and uvp should be locked and opened on entry and will be locked and 972 * opened on return. 973 */ 974 static int 975 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, 976 struct ucred *cred, struct thread *td) 977 { 978 int error; 979 off_t offset; 980 int count; 981 int bufoffset; 982 char *buf; 983 struct uio uio; 984 struct iovec iov; 985 986 error = 0; 987 memset(&uio, 0, sizeof(uio)); 988 989 uio.uio_td = td; 990 uio.uio_segflg = UIO_SYSSPACE; 991 uio.uio_offset = 0; 992 993 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); 994 995 while (error == 0) { 996 offset = uio.uio_offset; 997 998 uio.uio_iov = &iov; 999 uio.uio_iovcnt = 1; 1000 iov.iov_base = buf; 1001 iov.iov_len = MAXBSIZE; 1002 uio.uio_resid = iov.iov_len; 1003 uio.uio_rw = UIO_READ; 1004 1005 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) 1006 break; 1007 if ((count = MAXBSIZE - uio.uio_resid) == 0) 1008 break; 1009 1010 bufoffset = 0; 1011 while (bufoffset < count) { 1012 uio.uio_iov = &iov; 1013 uio.uio_iovcnt = 1; 1014 iov.iov_base = buf + bufoffset; 1015 iov.iov_len = count - bufoffset; 1016 uio.uio_offset = offset + bufoffset; 1017 uio.uio_resid = iov.iov_len; 1018 uio.uio_rw = UIO_WRITE; 1019 1020 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) 1021 break; 1022 1023 bufoffset += (count - bufoffset) - uio.uio_resid; 1024 } 1025 1026 uio.uio_offset = offset + bufoffset; 1027 } 1028 1029 free(buf, M_TEMP); 1030 1031 return (error); 1032 } 1033 1034 /* 1035 * Copy file from lower to upper. 1036 * 1037 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to 1038 * docopy. 1039 * 1040 * If no error returned, unp will be updated. 1041 */ 1042 int 1043 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, 1044 struct thread *td) 1045 { 1046 int error; 1047 struct mount *mp; 1048 struct vnode *udvp; 1049 struct vnode *lvp; 1050 struct vnode *uvp; 1051 struct vattr uva; 1052 1053 lvp = unp->un_lowervp; 1054 uvp = NULLVP; 1055 1056 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) 1057 return (EROFS); 1058 if (unp->un_dvp == NULLVP) 1059 return (EINVAL); 1060 if (unp->un_uppervp != NULLVP) 1061 return (EEXIST); 1062 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; 1063 if (udvp == NULLVP) 1064 return (EROFS); 1065 if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) 1066 return (EROFS); 1067 1068 error = VOP_ACCESS(lvp, VREAD, cred, td); 1069 if (error != 0) 1070 return (error); 1071 1072 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0) 1073 return (error); 1074 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); 1075 if (error != 0) { 1076 vn_finished_write(mp); 1077 return (error); 1078 } 1079 1080 if (docopy != 0) { 1081 error = VOP_OPEN(lvp, FREAD, cred, td, NULL); 1082 if (error == 0) { 1083 error = unionfs_copyfile_core(lvp, uvp, cred, td); 1084 VOP_CLOSE(lvp, FREAD, cred, td); 1085 } 1086 } 1087 VOP_CLOSE(uvp, FWRITE, cred, td); 1088 uvp->v_writecount--; 1089 1090 vn_finished_write(mp); 1091 1092 if (error == 0) { 1093 /* Reset the attributes. Ignore errors. */ 1094 uva.va_type = VNON; 1095 VOP_SETATTR(uvp, &uva, cred); 1096 } 1097 1098 unionfs_node_update(unp, uvp, td); 1099 1100 return (error); 1101 } 1102 1103 /* 1104 * It checks whether vp can rmdir. (check empty) 1105 * 1106 * vp is unionfs vnode. 1107 * vp should be locked. 1108 */ 1109 int 1110 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) 1111 { 1112 int error; 1113 int eofflag; 1114 int lookuperr; 1115 struct vnode *uvp; 1116 struct vnode *lvp; 1117 struct vnode *tvp; 1118 struct vattr va; 1119 struct componentname cn; 1120 /* 1121 * The size of buf needs to be larger than DIRBLKSIZ. 1122 */ 1123 char buf[256 * 6]; 1124 struct dirent *dp; 1125 struct dirent *edp; 1126 struct uio uio; 1127 struct iovec iov; 1128 1129 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir"); 1130 1131 eofflag = 0; 1132 uvp = UNIONFSVPTOUPPERVP(vp); 1133 lvp = UNIONFSVPTOLOWERVP(vp); 1134 1135 /* check opaque */ 1136 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) 1137 return (error); 1138 if (va.va_flags & OPAQUE) 1139 return (0); 1140 1141 /* open vnode */ 1142 #ifdef MAC 1143 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) 1144 return (error); 1145 #endif 1146 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) 1147 return (error); 1148 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) 1149 return (error); 1150 1151 uio.uio_rw = UIO_READ; 1152 uio.uio_segflg = UIO_SYSSPACE; 1153 uio.uio_td = td; 1154 uio.uio_offset = 0; 1155 1156 #ifdef MAC 1157 error = mac_vnode_check_readdir(td->td_ucred, lvp); 1158 #endif 1159 while (!error && !eofflag) { 1160 iov.iov_base = buf; 1161 iov.iov_len = sizeof(buf); 1162 uio.uio_iov = &iov; 1163 uio.uio_iovcnt = 1; 1164 uio.uio_resid = iov.iov_len; 1165 1166 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); 1167 if (error != 0) 1168 break; 1169 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) { 1170 #ifdef DIAGNOSTIC 1171 panic("bad readdir response from lower FS."); 1172 #endif 1173 break; 1174 } 1175 1176 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; 1177 for (dp = (struct dirent*)buf; !error && dp < edp; 1178 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { 1179 if (dp->d_type == DT_WHT || 1180 (dp->d_namlen == 1 && dp->d_name[0] == '.') || 1181 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) 1182 continue; 1183 1184 cn.cn_namelen = dp->d_namlen; 1185 cn.cn_pnbuf = NULL; 1186 cn.cn_nameptr = dp->d_name; 1187 cn.cn_nameiop = LOOKUP; 1188 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1189 cn.cn_lkflags = LK_EXCLUSIVE; 1190 cn.cn_thread = td; 1191 cn.cn_cred = cred; 1192 cn.cn_consume = 0; 1193 1194 /* 1195 * check entry in lower. 1196 * Sometimes, readdir function returns 1197 * wrong entry. 1198 */ 1199 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1200 1201 if (!lookuperr) 1202 vput(tvp); 1203 else 1204 continue; /* skip entry */ 1205 1206 /* 1207 * check entry 1208 * If it has no exist/whiteout entry in upper, 1209 * directory is not empty. 1210 */ 1211 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1212 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1213 1214 if (!lookuperr) 1215 vput(tvp); 1216 1217 /* ignore exist or whiteout entry */ 1218 if (!lookuperr || 1219 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1220 continue; 1221 1222 error = ENOTEMPTY; 1223 } 1224 } 1225 1226 /* close vnode */ 1227 VOP_CLOSE(vp, FREAD, cred, td); 1228 1229 return (error); 1230 } 1231 1232 #ifdef DIAGNOSTIC 1233 1234 struct vnode * 1235 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) 1236 { 1237 struct unionfs_node *unp; 1238 1239 unp = VTOUNIONFS(vp); 1240 1241 #ifdef notyet 1242 if (vp->v_op != unionfs_vnodeop_p) { 1243 printf("unionfs_checkuppervp: on non-unionfs-node.\n"); 1244 #ifdef KDB 1245 kdb_enter(KDB_WHY_UNIONFS, 1246 "unionfs_checkuppervp: on non-unionfs-node.\n"); 1247 #endif 1248 panic("unionfs_checkuppervp"); 1249 }; 1250 #endif 1251 return (unp->un_uppervp); 1252 } 1253 1254 struct vnode * 1255 unionfs_checklowervp(struct vnode *vp, char *fil, int lno) 1256 { 1257 struct unionfs_node *unp; 1258 1259 unp = VTOUNIONFS(vp); 1260 1261 #ifdef notyet 1262 if (vp->v_op != unionfs_vnodeop_p) { 1263 printf("unionfs_checklowervp: on non-unionfs-node.\n"); 1264 #ifdef KDB 1265 kdb_enter(KDB_WHY_UNIONFS, 1266 "unionfs_checklowervp: on non-unionfs-node.\n"); 1267 #endif 1268 panic("unionfs_checklowervp"); 1269 }; 1270 #endif 1271 return (unp->un_lowervp); 1272 } 1273 #endif
Cache object: 35bc7f34d58c43eacf465fd0286ba097
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