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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/10.0/sys/fs/unionfs/union_subr.c 243311 2012-11-19 22:43:45Z attilio $ 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); 539 540 vref(dvp); 541 VOP_UNLOCK(dvp, LK_RELEASE); 542 543 if ((error = relookup(dvp, vpp, cn))) { 544 uma_zfree(namei_zone, cn->cn_pnbuf); 545 cn->cn_flags &= ~HASBUF; 546 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); 547 } else 548 vrele(dvp); 549 550 return (error); 551 } 552 553 /* 554 * relookup for CREATE namei operation. 555 * 556 * dvp is unionfs vnode. dvp should be locked. 557 * 558 * If it called 'unionfs_copyfile' function by unionfs_link etc, 559 * VOP_LOOKUP information is broken. 560 * So it need relookup in order to create link etc. 561 */ 562 int 563 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, 564 struct thread *td) 565 { 566 int error; 567 struct vnode *udvp; 568 struct vnode *vp; 569 struct componentname cn; 570 571 udvp = UNIONFSVPTOUPPERVP(dvp); 572 vp = NULLVP; 573 574 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 575 strlen(cnp->cn_nameptr), CREATE); 576 if (error) 577 return (error); 578 579 if (vp != NULLVP) { 580 if (udvp == vp) 581 vrele(vp); 582 else 583 vput(vp); 584 585 error = EEXIST; 586 } 587 588 if (cn.cn_flags & HASBUF) { 589 uma_zfree(namei_zone, cn.cn_pnbuf); 590 cn.cn_flags &= ~HASBUF; 591 } 592 593 if (!error) { 594 cn.cn_flags |= (cnp->cn_flags & HASBUF); 595 cnp->cn_flags = cn.cn_flags; 596 } 597 598 return (error); 599 } 600 601 /* 602 * relookup for DELETE namei operation. 603 * 604 * dvp is unionfs vnode. dvp should be locked. 605 */ 606 int 607 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, 608 struct thread *td) 609 { 610 int error; 611 struct vnode *udvp; 612 struct vnode *vp; 613 struct componentname cn; 614 615 udvp = UNIONFSVPTOUPPERVP(dvp); 616 vp = NULLVP; 617 618 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 619 strlen(cnp->cn_nameptr), DELETE); 620 if (error) 621 return (error); 622 623 if (vp == NULLVP) 624 error = ENOENT; 625 else { 626 if (udvp == vp) 627 vrele(vp); 628 else 629 vput(vp); 630 } 631 632 if (cn.cn_flags & HASBUF) { 633 uma_zfree(namei_zone, cn.cn_pnbuf); 634 cn.cn_flags &= ~HASBUF; 635 } 636 637 if (!error) { 638 cn.cn_flags |= (cnp->cn_flags & HASBUF); 639 cnp->cn_flags = cn.cn_flags; 640 } 641 642 return (error); 643 } 644 645 /* 646 * relookup for RENAME namei operation. 647 * 648 * dvp is unionfs vnode. dvp should be locked. 649 */ 650 int 651 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, 652 struct thread *td) 653 { 654 int error; 655 struct vnode *udvp; 656 struct vnode *vp; 657 struct componentname cn; 658 659 udvp = UNIONFSVPTOUPPERVP(dvp); 660 vp = NULLVP; 661 662 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr, 663 strlen(cnp->cn_nameptr), RENAME); 664 if (error) 665 return (error); 666 667 if (vp != NULLVP) { 668 if (udvp == vp) 669 vrele(vp); 670 else 671 vput(vp); 672 } 673 674 if (cn.cn_flags & HASBUF) { 675 uma_zfree(namei_zone, cn.cn_pnbuf); 676 cn.cn_flags &= ~HASBUF; 677 } 678 679 if (!error) { 680 cn.cn_flags |= (cnp->cn_flags & HASBUF); 681 cnp->cn_flags = cn.cn_flags; 682 } 683 684 return (error); 685 686 } 687 688 /* 689 * Update the unionfs_node. 690 * 691 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the 692 * uvp's lock and lower's lock will be unlocked. 693 */ 694 static void 695 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp, 696 struct thread *td) 697 { 698 unsigned count, lockrec; 699 struct vnode *vp; 700 struct vnode *lvp; 701 struct vnode *dvp; 702 703 vp = UNIONFSTOV(unp); 704 lvp = unp->un_lowervp; 705 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update"); 706 dvp = unp->un_dvp; 707 708 /* 709 * lock update 710 */ 711 VI_LOCK(vp); 712 unp->un_uppervp = uvp; 713 vp->v_vnlock = uvp->v_vnlock; 714 VI_UNLOCK(vp); 715 lockrec = lvp->v_vnlock->lk_recurse; 716 for (count = 0; count < lockrec; count++) 717 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY); 718 719 /* 720 * cache update 721 */ 722 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) { 723 static struct unionfs_node_hashhead *hd; 724 725 VI_LOCK(dvp); 726 hd = unionfs_get_hashhead(dvp, unp->un_path); 727 LIST_REMOVE(unp, un_hash); 728 LIST_INSERT_HEAD(hd, unp, un_hash); 729 VI_UNLOCK(dvp); 730 } 731 } 732 733 /* 734 * Create a new shadow dir. 735 * 736 * udvp should be locked on entry and will be locked on return. 737 * 738 * If no error returned, unp will be updated. 739 */ 740 int 741 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp, 742 struct unionfs_node *unp, struct componentname *cnp, 743 struct thread *td) 744 { 745 int error; 746 struct vnode *lvp; 747 struct vnode *uvp; 748 struct vattr va; 749 struct vattr lva; 750 struct componentname cn; 751 struct mount *mp; 752 struct ucred *cred; 753 struct ucred *credbk; 754 struct uidinfo *rootinfo; 755 756 if (unp->un_uppervp != NULLVP) 757 return (EEXIST); 758 759 lvp = unp->un_lowervp; 760 uvp = NULLVP; 761 credbk = cnp->cn_cred; 762 763 /* Authority change to root */ 764 rootinfo = uifind((uid_t)0); 765 cred = crdup(cnp->cn_cred); 766 /* 767 * The calls to chgproccnt() are needed to compensate for change_ruid() 768 * calling chgproccnt(). 769 */ 770 chgproccnt(cred->cr_ruidinfo, 1, 0); 771 change_euid(cred, rootinfo); 772 change_ruid(cred, rootinfo); 773 change_svuid(cred, (uid_t)0); 774 uifree(rootinfo); 775 cnp->cn_cred = cred; 776 777 memset(&cn, 0, sizeof(cn)); 778 779 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred))) 780 goto unionfs_mkshadowdir_abort; 781 782 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE))) 783 goto unionfs_mkshadowdir_abort; 784 if (uvp != NULLVP) { 785 if (udvp == uvp) 786 vrele(uvp); 787 else 788 vput(uvp); 789 790 error = EEXIST; 791 goto unionfs_mkshadowdir_free_out; 792 } 793 794 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH))) 795 goto unionfs_mkshadowdir_free_out; 796 unionfs_create_uppervattr_core(ump, &lva, &va, td); 797 798 error = VOP_MKDIR(udvp, &uvp, &cn, &va); 799 800 if (!error) { 801 unionfs_node_update(unp, uvp, td); 802 803 /* 804 * XXX The bug which cannot set uid/gid was corrected. 805 * Ignore errors. 806 */ 807 va.va_type = VNON; 808 VOP_SETATTR(uvp, &va, cn.cn_cred); 809 } 810 vn_finished_write(mp); 811 812 unionfs_mkshadowdir_free_out: 813 if (cn.cn_flags & HASBUF) { 814 uma_zfree(namei_zone, cn.cn_pnbuf); 815 cn.cn_flags &= ~HASBUF; 816 } 817 818 unionfs_mkshadowdir_abort: 819 cnp->cn_cred = credbk; 820 chgproccnt(cred->cr_ruidinfo, -1, 0); 821 crfree(cred); 822 823 return (error); 824 } 825 826 /* 827 * Create a new whiteout. 828 * 829 * dvp should be locked on entry and will be locked on return. 830 */ 831 int 832 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, 833 struct thread *td, char *path) 834 { 835 int error; 836 struct vnode *wvp; 837 struct componentname cn; 838 struct mount *mp; 839 840 if (path == NULL) 841 path = cnp->cn_nameptr; 842 843 wvp = NULLVP; 844 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE))) 845 return (error); 846 if (wvp != NULLVP) { 847 if (cn.cn_flags & HASBUF) { 848 uma_zfree(namei_zone, cn.cn_pnbuf); 849 cn.cn_flags &= ~HASBUF; 850 } 851 if (dvp == wvp) 852 vrele(wvp); 853 else 854 vput(wvp); 855 856 return (EEXIST); 857 } 858 859 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH))) 860 goto unionfs_mkwhiteout_free_out; 861 error = VOP_WHITEOUT(dvp, &cn, CREATE); 862 863 vn_finished_write(mp); 864 865 unionfs_mkwhiteout_free_out: 866 if (cn.cn_flags & HASBUF) { 867 uma_zfree(namei_zone, cn.cn_pnbuf); 868 cn.cn_flags &= ~HASBUF; 869 } 870 871 return (error); 872 } 873 874 /* 875 * Create a new vnode for create a new shadow file. 876 * 877 * If an error is returned, *vpp will be invalid, otherwise it will hold a 878 * locked, referenced and opened vnode. 879 * 880 * unp is never updated. 881 */ 882 static int 883 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp, 884 struct unionfs_node *unp, struct vattr *uvap, 885 struct thread *td) 886 { 887 struct unionfs_mount *ump; 888 struct vnode *vp; 889 struct vnode *lvp; 890 struct ucred *cred; 891 struct vattr lva; 892 int fmode; 893 int error; 894 struct componentname cn; 895 896 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount); 897 vp = NULLVP; 898 lvp = unp->un_lowervp; 899 cred = td->td_ucred; 900 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL); 901 error = 0; 902 903 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0) 904 return (error); 905 unionfs_create_uppervattr_core(ump, &lva, uvap, td); 906 907 if (unp->un_path == NULL) 908 panic("unionfs: un_path is null"); 909 910 cn.cn_namelen = strlen(unp->un_path); 911 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 912 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1); 913 cn.cn_nameiop = CREATE; 914 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN); 915 cn.cn_lkflags = LK_EXCLUSIVE; 916 cn.cn_thread = td; 917 cn.cn_cred = cred; 918 cn.cn_nameptr = cn.cn_pnbuf; 919 cn.cn_consume = 0; 920 921 vref(udvp); 922 if ((error = relookup(udvp, &vp, &cn)) != 0) 923 goto unionfs_vn_create_on_upper_free_out2; 924 vrele(udvp); 925 926 if (vp != NULLVP) { 927 if (vp == udvp) 928 vrele(vp); 929 else 930 vput(vp); 931 error = EEXIST; 932 goto unionfs_vn_create_on_upper_free_out1; 933 } 934 935 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0) 936 goto unionfs_vn_create_on_upper_free_out1; 937 938 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) { 939 vput(vp); 940 goto unionfs_vn_create_on_upper_free_out1; 941 } 942 VOP_ADD_WRITECOUNT(vp, 1); 943 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, 944 vp->v_writecount); 945 *vpp = vp; 946 947 unionfs_vn_create_on_upper_free_out1: 948 VOP_UNLOCK(udvp, LK_RELEASE); 949 950 unionfs_vn_create_on_upper_free_out2: 951 if (cn.cn_flags & HASBUF) { 952 uma_zfree(namei_zone, cn.cn_pnbuf); 953 cn.cn_flags &= ~HASBUF; 954 } 955 956 return (error); 957 } 958 959 /* 960 * Copy from lvp to uvp. 961 * 962 * lvp and uvp should be locked and opened on entry and will be locked and 963 * opened on return. 964 */ 965 static int 966 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp, 967 struct ucred *cred, struct thread *td) 968 { 969 int error; 970 off_t offset; 971 int count; 972 int bufoffset; 973 char *buf; 974 struct uio uio; 975 struct iovec iov; 976 977 error = 0; 978 memset(&uio, 0, sizeof(uio)); 979 980 uio.uio_td = td; 981 uio.uio_segflg = UIO_SYSSPACE; 982 uio.uio_offset = 0; 983 984 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); 985 986 while (error == 0) { 987 offset = uio.uio_offset; 988 989 uio.uio_iov = &iov; 990 uio.uio_iovcnt = 1; 991 iov.iov_base = buf; 992 iov.iov_len = MAXBSIZE; 993 uio.uio_resid = iov.iov_len; 994 uio.uio_rw = UIO_READ; 995 996 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0) 997 break; 998 if ((count = MAXBSIZE - uio.uio_resid) == 0) 999 break; 1000 1001 bufoffset = 0; 1002 while (bufoffset < count) { 1003 uio.uio_iov = &iov; 1004 uio.uio_iovcnt = 1; 1005 iov.iov_base = buf + bufoffset; 1006 iov.iov_len = count - bufoffset; 1007 uio.uio_offset = offset + bufoffset; 1008 uio.uio_resid = iov.iov_len; 1009 uio.uio_rw = UIO_WRITE; 1010 1011 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0) 1012 break; 1013 1014 bufoffset += (count - bufoffset) - uio.uio_resid; 1015 } 1016 1017 uio.uio_offset = offset + bufoffset; 1018 } 1019 1020 free(buf, M_TEMP); 1021 1022 return (error); 1023 } 1024 1025 /* 1026 * Copy file from lower to upper. 1027 * 1028 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to 1029 * docopy. 1030 * 1031 * If no error returned, unp will be updated. 1032 */ 1033 int 1034 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, 1035 struct thread *td) 1036 { 1037 int error; 1038 struct mount *mp; 1039 struct vnode *udvp; 1040 struct vnode *lvp; 1041 struct vnode *uvp; 1042 struct vattr uva; 1043 1044 lvp = unp->un_lowervp; 1045 uvp = NULLVP; 1046 1047 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY)) 1048 return (EROFS); 1049 if (unp->un_dvp == NULLVP) 1050 return (EINVAL); 1051 if (unp->un_uppervp != NULLVP) 1052 return (EEXIST); 1053 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp; 1054 if (udvp == NULLVP) 1055 return (EROFS); 1056 if ((udvp->v_mount->mnt_flag & MNT_RDONLY)) 1057 return (EROFS); 1058 1059 error = VOP_ACCESS(lvp, VREAD, cred, td); 1060 if (error != 0) 1061 return (error); 1062 1063 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0) 1064 return (error); 1065 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td); 1066 if (error != 0) { 1067 vn_finished_write(mp); 1068 return (error); 1069 } 1070 1071 if (docopy != 0) { 1072 error = VOP_OPEN(lvp, FREAD, cred, td, NULL); 1073 if (error == 0) { 1074 error = unionfs_copyfile_core(lvp, uvp, cred, td); 1075 VOP_CLOSE(lvp, FREAD, cred, td); 1076 } 1077 } 1078 VOP_CLOSE(uvp, FWRITE, cred, td); 1079 VOP_ADD_WRITECOUNT(uvp, -1); 1080 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d", __func__, uvp, 1081 uvp->v_writecount); 1082 1083 vn_finished_write(mp); 1084 1085 if (error == 0) { 1086 /* Reset the attributes. Ignore errors. */ 1087 uva.va_type = VNON; 1088 VOP_SETATTR(uvp, &uva, cred); 1089 } 1090 1091 unionfs_node_update(unp, uvp, td); 1092 1093 return (error); 1094 } 1095 1096 /* 1097 * It checks whether vp can rmdir. (check empty) 1098 * 1099 * vp is unionfs vnode. 1100 * vp should be locked. 1101 */ 1102 int 1103 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td) 1104 { 1105 int error; 1106 int eofflag; 1107 int lookuperr; 1108 struct vnode *uvp; 1109 struct vnode *lvp; 1110 struct vnode *tvp; 1111 struct vattr va; 1112 struct componentname cn; 1113 /* 1114 * The size of buf needs to be larger than DIRBLKSIZ. 1115 */ 1116 char buf[256 * 6]; 1117 struct dirent *dp; 1118 struct dirent *edp; 1119 struct uio uio; 1120 struct iovec iov; 1121 1122 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir"); 1123 1124 eofflag = 0; 1125 uvp = UNIONFSVPTOUPPERVP(vp); 1126 lvp = UNIONFSVPTOLOWERVP(vp); 1127 1128 /* check opaque */ 1129 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0) 1130 return (error); 1131 if (va.va_flags & OPAQUE) 1132 return (0); 1133 1134 /* open vnode */ 1135 #ifdef MAC 1136 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0) 1137 return (error); 1138 #endif 1139 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0) 1140 return (error); 1141 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0) 1142 return (error); 1143 1144 uio.uio_rw = UIO_READ; 1145 uio.uio_segflg = UIO_SYSSPACE; 1146 uio.uio_td = td; 1147 uio.uio_offset = 0; 1148 1149 #ifdef MAC 1150 error = mac_vnode_check_readdir(td->td_ucred, lvp); 1151 #endif 1152 while (!error && !eofflag) { 1153 iov.iov_base = buf; 1154 iov.iov_len = sizeof(buf); 1155 uio.uio_iov = &iov; 1156 uio.uio_iovcnt = 1; 1157 uio.uio_resid = iov.iov_len; 1158 1159 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL); 1160 if (error != 0) 1161 break; 1162 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) { 1163 #ifdef DIAGNOSTIC 1164 panic("bad readdir response from lower FS."); 1165 #endif 1166 break; 1167 } 1168 1169 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid]; 1170 for (dp = (struct dirent*)buf; !error && dp < edp; 1171 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) { 1172 if (dp->d_type == DT_WHT || dp->d_fileno == 0 || 1173 (dp->d_namlen == 1 && dp->d_name[0] == '.') || 1174 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2))) 1175 continue; 1176 1177 cn.cn_namelen = dp->d_namlen; 1178 cn.cn_pnbuf = NULL; 1179 cn.cn_nameptr = dp->d_name; 1180 cn.cn_nameiop = LOOKUP; 1181 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1182 cn.cn_lkflags = LK_EXCLUSIVE; 1183 cn.cn_thread = td; 1184 cn.cn_cred = cred; 1185 cn.cn_consume = 0; 1186 1187 /* 1188 * check entry in lower. 1189 * Sometimes, readdir function returns 1190 * wrong entry. 1191 */ 1192 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn); 1193 1194 if (!lookuperr) 1195 vput(tvp); 1196 else 1197 continue; /* skip entry */ 1198 1199 /* 1200 * check entry 1201 * If it has no exist/whiteout entry in upper, 1202 * directory is not empty. 1203 */ 1204 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN); 1205 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn); 1206 1207 if (!lookuperr) 1208 vput(tvp); 1209 1210 /* ignore exist or whiteout entry */ 1211 if (!lookuperr || 1212 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT))) 1213 continue; 1214 1215 error = ENOTEMPTY; 1216 } 1217 } 1218 1219 /* close vnode */ 1220 VOP_CLOSE(vp, FREAD, cred, td); 1221 1222 return (error); 1223 } 1224 1225 #ifdef DIAGNOSTIC 1226 1227 struct vnode * 1228 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) 1229 { 1230 struct unionfs_node *unp; 1231 1232 unp = VTOUNIONFS(vp); 1233 1234 #ifdef notyet 1235 if (vp->v_op != unionfs_vnodeop_p) { 1236 printf("unionfs_checkuppervp: on non-unionfs-node.\n"); 1237 #ifdef KDB 1238 kdb_enter(KDB_WHY_UNIONFS, 1239 "unionfs_checkuppervp: on non-unionfs-node.\n"); 1240 #endif 1241 panic("unionfs_checkuppervp"); 1242 }; 1243 #endif 1244 return (unp->un_uppervp); 1245 } 1246 1247 struct vnode * 1248 unionfs_checklowervp(struct vnode *vp, char *fil, int lno) 1249 { 1250 struct unionfs_node *unp; 1251 1252 unp = VTOUNIONFS(vp); 1253 1254 #ifdef notyet 1255 if (vp->v_op != unionfs_vnodeop_p) { 1256 printf("unionfs_checklowervp: on non-unionfs-node.\n"); 1257 #ifdef KDB 1258 kdb_enter(KDB_WHY_UNIONFS, 1259 "unionfs_checklowervp: on non-unionfs-node.\n"); 1260 #endif 1261 panic("unionfs_checklowervp"); 1262 }; 1263 #endif 1264 return (unp->un_lowervp); 1265 } 1266 #endif
Cache object: 05f94ba171172ef4b200977996bd30ce
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