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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 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc. 6 * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org> 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Jan-Simon Pendry. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)union_subr.c 8.20 (Berkeley) 5/20/95 36 * $FreeBSD: releng/8.0/sys/fs/unionfs/union_subr.c 195995 2009-07-31 13:40:06Z jhb $ 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; 353 354 vp->v_vnlock = &(vp->v_lock); 355 vp->v_data = NULL; 356 lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_INTERLOCK, VI_MTX(vp)); 357 if (lvp != NULLVP) 358 VOP_UNLOCK(lvp, 0); 359 if (uvp != NULLVP) 360 VOP_UNLOCK(uvp, 0); 361 vp->v_object = NULL; 362 363 if (dvp != NULLVP && unp->un_hash.le_prev != NULL) 364 unionfs_rem_cached_vnode(unp, dvp); 365 366 if (lvp != NULLVP) { 367 vfslocked = VFS_LOCK_GIANT(lvp->v_mount); 368 vrele(lvp); 369 VFS_UNLOCK_GIANT(vfslocked); 370 } 371 if (uvp != NULLVP) { 372 vfslocked = VFS_LOCK_GIANT(uvp->v_mount); 373 vrele(uvp); 374 VFS_UNLOCK_GIANT(vfslocked); 375 } 376 if (dvp != NULLVP) { 377 vfslocked = VFS_LOCK_GIANT(dvp->v_mount); 378 vrele(dvp); 379 VFS_UNLOCK_GIANT(vfslocked); 380 unp->un_dvp = NULLVP; 381 } 382 if (unp->un_path != NULL) { 383 free(unp->un_path, M_UNIONFSPATH); 384 unp->un_path = NULL; 385 } 386 387 if (unp->un_hashtbl != NULL) { 388 for (count = 0; count <= unp->un_hashmask; count++) { 389 hd = unp->un_hashtbl + count; 390 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) { 391 LIST_REMOVE(unp_t1, un_hash); 392 unp_t1->un_hash.le_next = NULL; 393 unp_t1->un_hash.le_prev = NULL; 394 } 395 } 396 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask); 397 } 398 399 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) { 400 LIST_REMOVE(unsp, uns_list); 401 free(unsp, M_TEMP); 402 } 403 free(unp, M_UNIONFSNODE); 404 } 405 406 /* 407 * Get the unionfs node status. 408 * You need exclusive lock this vnode. 409 */ 410 void 411 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, 412 struct unionfs_node_status **unspp) 413 { 414 struct unionfs_node_status *unsp; 415 pid_t pid = td->td_proc->p_pid; 416 417 KASSERT(NULL != unspp, ("null pointer")); 418 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 419 420 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) { 421 if (unsp->uns_pid == pid) { 422 *unspp = unsp; 423 return; 424 } 425 } 426 427 /* create a new unionfs node status */ 428 unsp = malloc(sizeof(struct unionfs_node_status), 429 M_TEMP, M_WAITOK | M_ZERO); 430 431 unsp->uns_pid = pid; 432 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list); 433 434 *unspp = unsp; 435 } 436 437 /* 438 * Remove the unionfs node status, if you can. 439 * You need exclusive lock this vnode. 440 */ 441 void 442 unionfs_tryrem_node_status(struct unionfs_node *unp, 443 struct unionfs_node_status *unsp) 444 { 445 KASSERT(NULL != unsp, ("null pointer")); 446 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status"); 447 448 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt) 449 return; 450 451 LIST_REMOVE(unsp, uns_list); 452 free(unsp, M_TEMP); 453 } 454 455 /* 456 * Create upper node attr. 457 */ 458 void 459 unionfs_create_uppervattr_core(struct unionfs_mount *ump, 460 struct vattr *lva, 461 struct vattr *uva, 462 struct thread *td) 463 { 464 VATTR_NULL(uva); 465 uva->va_type = lva->va_type; 466 uva->va_atime = lva->va_atime; 467 uva->va_mtime = lva->va_mtime; 468 uva->va_ctime = lva->va_ctime; 469 470 switch (ump->um_copymode) { 471 case UNIONFS_TRANSPARENT: 472 uva->va_mode = lva->va_mode; 473 uva->va_uid = lva->va_uid; 474 uva->va_gid = lva->va_gid; 475 break; 476 case UNIONFS_MASQUERADE: 477 if (ump->um_uid == lva->va_uid) { 478 uva->va_mode = lva->va_mode & 077077; 479 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700; 480 uva->va_uid = lva->va_uid; 481 uva->va_gid = lva->va_gid; 482 } else { 483 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile); 484 uva->va_uid = ump->um_uid; 485 uva->va_gid = ump->um_gid; 486 } 487 break; 488 default: /* UNIONFS_TRADITIONAL */ 489 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask; 490 uva->va_uid = ump->um_uid; 491 uva->va_gid = ump->um_gid; 492 break; 493 } 494 } 495 496 /* 497 * Create upper node attr. 498 */ 499 int 500 unionfs_create_uppervattr(struct unionfs_mount *ump, 501 struct vnode *lvp, 502 struct vattr *uva, 503 struct ucred *cred, 504 struct thread *td) 505 { 506 int error; 507 struct vattr lva; 508 509 if ((error = VOP_GETATTR(lvp, &lva, cred))) 510 return (error); 511 512 unionfs_create_uppervattr_core(ump, &lva, uva, td); 513 514 return (error); 515 } 516 517 /* 518 * relookup 519 * 520 * dvp should be locked on entry and will be locked on return. 521 * 522 * If an error is returned, *vpp will be invalid, otherwise it will hold a 523 * locked, referenced vnode. If *vpp == dvp then remember that only one 524 * LK_EXCLUSIVE lock is held. 525 */ 526 int 527 unionfs_relookup(struct vnode *dvp, struct vnode **vpp, 528 struct componentname *cnp, struct componentname *cn, 529 struct thread *td, char *path, int pathlen, u_long nameiop) 530 { 531 int error; 532 533 cn->cn_namelen = pathlen; 534 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 535 bcopy(path, cn->cn_pnbuf, pathlen); 536 cn->cn_pnbuf[pathlen] = '\0'; 537 538 cn->cn_nameiop = nameiop; 539 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 540 cn->cn_lkflags = LK_EXCLUSIVE; 541 cn->cn_thread = td; 542 cn->cn_cred = cnp->cn_cred; 543 544 cn->cn_nameptr = cn->cn_pnbuf; 545 cn->cn_consume = cnp->cn_consume; 546 547 if (nameiop == DELETE) 548 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART)); 549 else if (RENAME == nameiop) 550 cn->cn_flags |= (cnp->cn_flags & SAVESTART); 551 552 vref(dvp); 553 VOP_UNLOCK(dvp, 0); 554 555 if ((error = relookup(dvp, vpp, cn))) { 556 uma_zfree(namei_zone, cn->cn_pnbuf); 557 cn->cn_flags &= ~HASBUF; 558 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 559 } else 560 vrele(dvp); 561 562 return (error); 563 } 564 565 /* 566 * relookup for CREATE namei operation. 567 * 568 * dvp is unionfs vnode. dvp should be locked. 569 * 570 * If it called 'unionfs_copyfile' function by unionfs_link etc, 571 * VOP_LOOKUP information is broken. 572 * So it need relookup in order to create link etc. 573 */ 574 int 575 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 576 struct thread *td) 577 { 578 int error; 579 struct vnode *udvp; 580 struct vnode *vp; 581 struct componentname cn; 582 583 udvp = UNIONFSVPTOUPPERVP(dvp); 584 vp = NULLVP; 585 586 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 587 strlen(cnp->cn_nameptr), CREATE); 588 if (error) 589 return (error); 590 591 if (vp != NULLVP) { 592 if (udvp == vp) 593 vrele(vp); 594 else 595 vput(vp); 596 597 error = EEXIST; 598 } 599 600 if (cn.cn_flags & HASBUF) { 601 uma_zfree(namei_zone, cn.cn_pnbuf); 602 cn.cn_flags &= ~HASBUF; 603 } 604 605 if (!error) { 606 cn.cn_flags |= (cnp->cn_flags & HASBUF); 607 cnp->cn_flags = cn.cn_flags; 608 } 609 610 return (error); 611 } 612 613 /* 614 * relookup for DELETE namei operation. 615 * 616 * dvp is unionfs vnode. dvp should be locked. 617 */ 618 int 619 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 620 struct thread *td) 621 { 622 int error; 623 struct vnode *udvp; 624 struct vnode *vp; 625 struct componentname cn; 626 627 udvp = UNIONFSVPTOUPPERVP(dvp); 628 vp = NULLVP; 629 630 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 631 strlen(cnp->cn_nameptr), DELETE); 632 if (error) 633 return (error); 634 635 if (vp == NULLVP) 636 error = ENOENT; 637 else { 638 if (udvp == vp) 639 vrele(vp); 640 else 641 vput(vp); 642 } 643 644 if (cn.cn_flags & HASBUF) { 645 uma_zfree(namei_zone, cn.cn_pnbuf); 646 cn.cn_flags &= ~HASBUF; 647 } 648 649 if (!error) { 650 cn.cn_flags |= (cnp->cn_flags & HASBUF); 651 cnp->cn_flags = cn.cn_flags; 652 } 653 654 return (error); 655 } 656 657 /* 658 * relookup for RENAME namei operation. 659 * 660 * dvp is unionfs vnode. dvp should be locked. 661 */ 662 int 663 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 664 struct thread *td) 665 { 666 int error; 667 struct vnode *udvp; 668 struct vnode *vp; 669 struct componentname cn; 670 671 udvp = UNIONFSVPTOUPPERVP(dvp); 672 vp = NULLVP; 673 674 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 675 strlen(cnp->cn_nameptr), RENAME); 676 if (error) 677 return (error); 678 679 if (vp != NULLVP) { 680 if (udvp == vp) 681 vrele(vp); 682 else 683 vput(vp); 684 } 685 686 if (cn.cn_flags & HASBUF) { 687 uma_zfree(namei_zone, cn.cn_pnbuf); 688 cn.cn_flags &= ~HASBUF; 689 } 690 691 if (!error) { 692 cn.cn_flags |= (cnp->cn_flags & HASBUF); 693 cnp->cn_flags = cn.cn_flags; 694 } 695 696 return (error); 697 698 } 699 700 /* 701 * Update the unionfs_node. 702 * 703 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 704 * uvp's lock and lower's lock will be unlocked. 705 */ 706 static void 707 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 708 struct thread *td) 709 { 710 unsigned count, lockrec; 711 struct vnode *vp; 712 struct vnode *lvp; 713 struct vnode *dvp; 714 715 vp = UNIONFSTOV(unp); 716 lvp = unp->un_lowervp; 717 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); 718 dvp = unp->un_dvp; 719 720 /* 721 * lock update 722 */ 723 VI_LOCK(vp); 724 unp->un_uppervp = uvp; 725 vp->v_vnlock = uvp->v_vnlock; 726 VI_UNLOCK(vp); 727 lockrec = lvp->v_vnlock->lk_recurse; 728 for (count = 0; count < lockrec; count++) 729 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 730 731 /* 732 * cache update 733 */ 734 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { 735 static struct unionfs_node_hashhead *hd; 736 737 VI_LOCK(dvp); 738 hd = unionfs_get_hashhead(dvp, unp->un_path); 739 LIST_REMOVE(unp, un_hash); 740 LIST_INSERT_HEAD(hd, unp, un_hash); 741 VI_UNLOCK(dvp); 742 } 743 } 744 745 /* 746 * Create a new shadow dir. 747 * 748 * udvp should be locked on entry and will be locked on return. 749 * 750 * If no error returned, unp will be updated. 751 */ 752 int 753 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 754 struct unionfs_node *unp, struct componentname *cnp, 755 struct thread *td) 756 { 757 int error; 758 struct vnode *lvp; 759 struct vnode *uvp; 760 struct vattr va; 761 struct vattr lva; 762 struct componentname cn; 763 struct mount *mp; 764 struct ucred *cred; 765 struct ucred *credbk; 766 struct uidinfo *rootinfo; 767 768 if (unp->un_uppervp != NULLVP) 769 return (EEXIST); 770 771 lvp = unp->un_lowervp; 772 uvp = NULLVP; 773 credbk = cnp->cn_cred; 774 775 /* Authority change to root */ 776 rootinfo = uifind((uid_t)0); 777 cred = crdup(cnp->cn_cred); 778 chgproccnt(cred->cr_ruidinfo, 1, 0); 779 change_euid(cred, rootinfo); 780 change_ruid(cred, rootinfo); 781 change_svuid(cred, (uid_t)0); 782 uifree(rootinfo); 783 cnp->cn_cred = cred; 784 785 memset(&cn, 0, sizeof(cn)); 786 787 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 788 goto unionfs_mkshadowdir_abort; 789 790 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 791 goto unionfs_mkshadowdir_abort; 792 if (uvp != NULLVP) { 793 if (udvp == uvp) 794 vrele(uvp); 795 else 796 vput(uvp); 797 798 error = EEXIST; 799 goto unionfs_mkshadowdir_free_out; 800 } 801 802 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) 803 goto unionfs_mkshadowdir_free_out; 804 unionfs_create_uppervattr_core(ump, &lva, &va, td); 805 806 error = VOP_MKDIR(udvp, &uvp, &cn, &va); 807 808 if (!error) { 809 unionfs_node_update(unp, uvp, td); 810 811 /* 812 * XXX The bug which cannot set uid/gid was corrected. 813 * Ignore errors. 814 */ 815 va.va_type = VNON; 816 VOP_SETATTR(uvp, &va, cn.cn_cred); 817 } 818 vn_finished_write(mp); 819 820 unionfs_mkshadowdir_free_out: 821 if (cn.cn_flags & HASBUF) { 822 uma_zfree(namei_zone, cn.cn_pnbuf); 823 cn.cn_flags &= ~HASBUF; 824 } 825 826 unionfs_mkshadowdir_abort: 827 cnp->cn_cred = credbk; 828 chgproccnt(cred->cr_ruidinfo, -1, 0); 829 crfree(cred); 830 831 return (error); 832 } 833 834 /* 835 * Create a new whiteout. 836 * 837 * dvp should be locked on entry and will be locked on return. 838 */ 839 int 840 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 841 struct thread *td, char *path) 842 { 843 int error; 844 struct vnode *wvp; 845 struct componentname cn; 846 struct mount *mp; 847 848 if (path == NULL) 849 path = cnp->cn_nameptr; 850 851 wvp = NULLVP; 852 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) 853 return (error); 854 if (wvp != NULLVP) { 855 if (cn.cn_flags & HASBUF) { 856 uma_zfree(namei_zone, cn.cn_pnbuf); 857 cn.cn_flags &= ~HASBUF; 858 } 859 if (dvp == wvp) 860 vrele(wvp); 861 else 862 vput(wvp); 863 864 return (EEXIST); 865 } 866 867 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) 868 goto unionfs_mkwhiteout_free_out; 869 error = VOP_WHITEOUT(dvp, &cn, CREATE); 870 871 vn_finished_write(mp); 872 873 unionfs_mkwhiteout_free_out: 874 if (cn.cn_flags & HASBUF) { 875 uma_zfree(namei_zone, cn.cn_pnbuf); 876 cn.cn_flags &= ~HASBUF; 877 } 878 879 return (error); 880 } 881 882 /* 883 * Create a new vnode for create a new shadow file. 884 * 885 * If an error is returned, *vpp will be invalid, otherwise it will hold a 886 * locked, referenced and opened vnode. 887 * 888 * unp is never updated. 889 */ 890 static int 891 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 892 struct unionfs_node *unp, struct vattr *uvap, 893 struct thread *td) 894 { 895 struct unionfs_mount *ump; 896 struct vnode *vp; 897 struct vnode *lvp; 898 struct ucred *cred; 899 struct vattr lva; 900 int fmode; 901 int error; 902 struct componentname cn; 903 904 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 905 vp = NULLVP; 906 lvp = unp->un_lowervp; 907 cred = td->td_ucred; 908 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 909 error = 0; 910 911 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 912 return (error); 913 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 914 915 if (unp->un_path == NULL) 916 panic("unionfs: un_path is null"); 917 918 cn.cn_namelen = strlen(unp->un_path); 919 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 920 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); 921 cn.cn_nameiop = CREATE; 922 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 923 cn.cn_lkflags = LK_EXCLUSIVE; 924 cn.cn_thread = td; 925 cn.cn_cred = cred; 926 cn.cn_nameptr = cn.cn_pnbuf; 927 cn.cn_consume = 0; 928 929 vref(udvp); 930 if ((error = relookup(udvp, &vp, &cn)) != 0) 931 goto unionfs_vn_create_on_upper_free_out2; 932 vrele(udvp); 933 934 if (vp != NULLVP) { 935 if (vp == udvp) 936 vrele(vp); 937 else 938 vput(vp); 939 error = EEXIST; 940 goto unionfs_vn_create_on_upper_free_out1; 941 } 942 943 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0) 944 goto unionfs_vn_create_on_upper_free_out1; 945 946 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { 947 vput(vp); 948 goto unionfs_vn_create_on_upper_free_out1; 949 } 950 vp->v_writecount++; 951 *vpp = vp; 952 953 unionfs_vn_create_on_upper_free_out1: 954 VOP_UNLOCK(udvp, 0); 955 956 unionfs_vn_create_on_upper_free_out2: 957 if (cn.cn_flags & HASBUF) { 958 uma_zfree(namei_zone, cn.cn_pnbuf); 959 cn.cn_flags &= ~HASBUF; 960 } 961 962 return (error); 963 } 964 965 /* 966 * Copy from lvp to uvp. 967 * 968 * lvp and uvp should be locked and opened on entry and will be locked and 969 * opened on return. 970 */ 971 static int 972 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, 973 struct ucred *cred, struct thread *td) 974 { 975 int error; 976 off_t offset; 977 int count; 978 int bufoffset; 979 char *buf; 980 struct uio uio; 981 struct iovec iov; 982 983 error = 0; 984 memset(&uio, 0, sizeof(uio)); 985 986 uio.uio_td = td; 987 uio.uio_segflg = UIO_SYSSPACE; 988 uio.uio_offset = 0; 989 990 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); 991 992 while (error == 0) { 993 offset = uio.uio_offset; 994 995 uio.uio_iov = &iov; 996 uio.uio_iovcnt = 1; 997 iov.iov_base = buf; 998 iov.iov_len = MAXBSIZE; 999 uio.uio_resid = iov.iov_len; 1000 uio.uio_rw = UIO_READ; 1001 1002 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) 1003 break; 1004 if ((count = MAXBSIZE - uio.uio_resid) == 0) 1005 break; 1006 1007 bufoffset = 0; 1008 while (bufoffset < count) { 1009 uio.uio_iov = &iov; 1010 uio.uio_iovcnt = 1; 1011 iov.iov_base = buf + bufoffset; 1012 iov.iov_len = count - bufoffset; 1013 uio.uio_offset = offset + bufoffset; 1014 uio.uio_resid = iov.iov_len; 1015 uio.uio_rw = UIO_WRITE; 1016 1017 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) 1018 break; 1019 1020 bufoffset += (count - bufoffset) - uio.uio_resid; 1021 } 1022 1023 uio.uio_offset = offset + bufoffset; 1024 } 1025 1026 free(buf, M_TEMP); 1027 1028 return (error); 1029 } 1030 1031 /* 1032 * Copy file from lower to upper. 1033 * 1034 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to 1035 * docopy. 1036 * 1037 * If no error returned, unp will be updated. 1038 */ 1039 int 1040 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, 1041 struct thread *td) 1042 { 1043 int error; 1044 struct mount *mp; 1045 struct vnode *udvp; 1046 struct vnode *lvp; 1047 struct vnode *uvp; 1048 struct vattr uva; 1049 1050 lvp = unp->un_lowervp; 1051 uvp = NULLVP; 1052 1053 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) 1054 return (EROFS); 1055 if (unp->un_dvp == NULLVP) 1056 return (EINVAL); 1057 if (unp->un_uppervp != NULLVP) 1058 return (EEXIST); 1059 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; 1060 if (udvp == NULLVP) 1061 return (EROFS); 1062 if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) 1063 return (EROFS); 1064 1065 error = VOP_ACCESS(lvp, VREAD, cred, td); 1066 if (error != 0) 1067 return (error); 1068 1069 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0) 1070 return (error); 1071 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); 1072 if (error != 0) { 1073 vn_finished_write(mp); 1074 return (error); 1075 } 1076 1077 if (docopy != 0) { 1078 error = VOP_OPEN(lvp, FREAD, cred, td, NULL); 1079 if (error == 0) { 1080 error = unionfs_copyfile_core(lvp, uvp, cred, td); 1081 VOP_CLOSE(lvp, FREAD, cred, td); 1082 } 1083 } 1084 VOP_CLOSE(uvp, FWRITE, cred, td); 1085 uvp->v_writecount--; 1086 1087 vn_finished_write(mp); 1088 1089 if (error == 0) { 1090 /* Reset the attributes. Ignore errors. */ 1091 uva.va_type = VNON; 1092 VOP_SETATTR(uvp, &uva, cred); 1093 } 1094 1095 unionfs_node_update(unp, uvp, td); 1096 1097 return (error); 1098 } 1099 1100 /* 1101 * It checks whether vp can rmdir. (check empty) 1102 * 1103 * vp is unionfs vnode. 1104 * vp should be locked. 1105 */ 1106 int 1107 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) 1108 { 1109 int error; 1110 int eofflag; 1111 int lookuperr; 1112 struct vnode *uvp; 1113 struct vnode *lvp; 1114 struct vnode *tvp; 1115 struct vattr va; 1116 struct componentname cn; 1117 /* 1118 * The size of buf needs to be larger than DIRBLKSIZ. 1119 */ 1120 char buf[256 * 6]; 1121 struct dirent *dp; 1122 struct dirent *edp; 1123 struct uio uio; 1124 struct iovec iov; 1125 1126 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir"); 1127 1128 eofflag = 0; 1129 uvp = UNIONFSVPTOUPPERVP(vp); 1130 lvp = UNIONFSVPTOLOWERVP(vp); 1131 1132 /* check opaque */ 1133 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) 1134 return (error); 1135 if (va.va_flags & OPAQUE) 1136 return (0); 1137 1138 /* open vnode */ 1139 #ifdef MAC 1140 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) 1141 return (error); 1142 #endif 1143 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) 1144 return (error); 1145 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) 1146 return (error); 1147 1148 uio.uio_rw = UIO_READ; 1149 uio.uio_segflg = UIO_SYSSPACE; 1150 uio.uio_td = td; 1151 uio.uio_offset = 0; 1152 1153 #ifdef MAC 1154 error = mac_vnode_check_readdir(td->td_ucred, lvp); 1155 #endif 1156 while (!error && !eofflag) { 1157 iov.iov_base = buf; 1158 iov.iov_len = sizeof(buf); 1159 uio.uio_iov = &iov; 1160 uio.uio_iovcnt = 1; 1161 uio.uio_resid = iov.iov_len; 1162 1163 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); 1164 if (error != 0) 1165 break; 1166 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) { 1167 #ifdef DIAGNOSTIC 1168 panic("bad readdir response from lower FS."); 1169 #endif 1170 break; 1171 } 1172 1173 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; 1174 for (dp = (struct dirent*)buf; !error && dp < edp; 1175 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { 1176 if (dp->d_type == DT_WHT || 1177 (dp->d_namlen == 1 && dp->d_name[0] == '.') || 1178 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) 1179 continue; 1180 1181 cn.cn_namelen = dp->d_namlen; 1182 cn.cn_pnbuf = NULL; 1183 cn.cn_nameptr = dp->d_name; 1184 cn.cn_nameiop = LOOKUP; 1185 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1186 cn.cn_lkflags = LK_EXCLUSIVE; 1187 cn.cn_thread = td; 1188 cn.cn_cred = cred; 1189 cn.cn_consume = 0; 1190 1191 /* 1192 * check entry in lower. 1193 * Sometimes, readdir function returns 1194 * wrong entry. 1195 */ 1196 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1197 1198 if (!lookuperr) 1199 vput(tvp); 1200 else 1201 continue; /* skip entry */ 1202 1203 /* 1204 * check entry 1205 * If it has no exist/whiteout entry in upper, 1206 * directory is not empty. 1207 */ 1208 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1209 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1210 1211 if (!lookuperr) 1212 vput(tvp); 1213 1214 /* ignore exist or whiteout entry */ 1215 if (!lookuperr || 1216 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1217 continue; 1218 1219 error = ENOTEMPTY; 1220 } 1221 } 1222 1223 /* close vnode */ 1224 VOP_CLOSE(vp, FREAD, cred, td); 1225 1226 return (error); 1227 } 1228 1229 #ifdef DIAGNOSTIC 1230 1231 struct vnode * 1232 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) 1233 { 1234 struct unionfs_node *unp; 1235 1236 unp = VTOUNIONFS(vp); 1237 1238 #ifdef notyet 1239 if (vp->v_op != unionfs_vnodeop_p) { 1240 printf("unionfs_checkuppervp: on non-unionfs-node.\n"); 1241 #ifdef KDB 1242 kdb_enter(KDB_WHY_UNIONFS, 1243 "unionfs_checkuppervp: on non-unionfs-node.\n"); 1244 #endif 1245 panic("unionfs_checkuppervp"); 1246 }; 1247 #endif 1248 return (unp->un_uppervp); 1249 } 1250 1251 struct vnode * 1252 unionfs_checklowervp(struct vnode *vp, char *fil, int lno) 1253 { 1254 struct unionfs_node *unp; 1255 1256 unp = VTOUNIONFS(vp); 1257 1258 #ifdef notyet 1259 if (vp->v_op != unionfs_vnodeop_p) { 1260 printf("unionfs_checklowervp: on non-unionfs-node.\n"); 1261 #ifdef KDB 1262 kdb_enter(KDB_WHY_UNIONFS, 1263 "unionfs_checklowervp: on non-unionfs-node.\n"); 1264 #endif 1265 panic("unionfs_checklowervp"); 1266 }; 1267 #endif 1268 return (unp->un_lowervp); 1269 } 1270 #endif
Cache object: f730ae45cb0ad30a66c0c8694083ce0f
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