xfs_rename.c revision 267654
1/* 2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18#include "xfs.h" 19#include "xfs_fs.h" 20#include "xfs_types.h" 21#include "xfs_log.h" 22#include "xfs_inum.h" 23#include "xfs_trans.h" 24#include "xfs_sb.h" 25#include "xfs_dir.h" 26#include "xfs_dir2.h" 27#include "xfs_dmapi.h" 28#include "xfs_mount.h" 29#include "xfs_da_btree.h" 30#include "xfs_bmap_btree.h" 31#include "xfs_dir_sf.h" 32#include "xfs_dir2_sf.h" 33#include "xfs_attr_sf.h" 34#include "xfs_dinode.h" 35#include "xfs_inode.h" 36#include "xfs_inode_item.h" 37#include "xfs_bmap.h" 38#include "xfs_error.h" 39#include "xfs_quota.h" 40#include "xfs_refcache.h" 41#include "xfs_utils.h" 42#include "xfs_trans_space.h" 43#include "xfs_dir_leaf.h" 44 45 46/* 47 * Given an array of up to 4 inode pointers, unlock the pointed to inodes. 48 * If there are fewer than 4 entries in the array, the empty entries will 49 * be at the end and will have NULL pointers in them. 50 */ 51STATIC void 52xfs_rename_unlock4( 53 xfs_inode_t **i_tab, 54 uint lock_mode) 55{ 56 int i; 57 58 xfs_iunlock(i_tab[0], lock_mode); 59 for (i = 1; i < 4; i++) { 60 if (i_tab[i] == NULL) { 61 break; 62 } 63 /* 64 * Watch out for duplicate entries in the table. 65 */ 66 if (i_tab[i] != i_tab[i-1]) { 67 xfs_iunlock(i_tab[i], lock_mode); 68 } 69 } 70} 71 72#ifdef DEBUG 73int xfs_rename_skip, xfs_rename_nskip; 74#endif 75 76/* 77 * The following routine will acquire the locks required for a rename 78 * operation. The code understands the semantics of renames and will 79 * validate that name1 exists under dp1 & that name2 may or may not 80 * exist under dp2. 81 * 82 * We are renaming dp1/name1 to dp2/name2. 83 * 84 * Return ENOENT if dp1 does not exist, other lookup errors, or 0 for success. 85 */ 86STATIC int 87xfs_lock_for_rename( 88 xfs_inode_t *dp1, /* old (source) directory inode */ 89 xfs_inode_t *dp2, /* new (target) directory inode */ 90 vname_t *vname1,/* old entry name */ 91 vname_t *vname2,/* new entry name */ 92 xfs_inode_t **ipp1, /* inode of old entry */ 93 xfs_inode_t **ipp2, /* inode of new entry, if it 94 already exists, NULL otherwise. */ 95 xfs_inode_t **i_tab,/* array of inode returned, sorted */ 96 int *num_inodes) /* number of inodes in array */ 97{ 98 xfs_inode_t *ip1, *ip2, *temp; 99 xfs_ino_t inum1, inum2; 100 int error; 101 int i, j; 102 uint lock_mode; 103 int diff_dirs = (dp1 != dp2); 104 105 ip2 = NULL; 106 107 /* 108 * First, find out the current inums of the entries so that we 109 * can determine the initial locking order. We'll have to 110 * sanity check stuff after all the locks have been acquired 111 * to see if we still have the right inodes, directories, etc. 112 */ 113 lock_mode = xfs_ilock_map_shared(dp1); 114 error = xfs_get_dir_entry(vname1, &ip1); 115 if (error) { 116 xfs_iunlock_map_shared(dp1, lock_mode); 117 return error; 118 } 119 120 inum1 = ip1->i_ino; 121 122 ASSERT(ip1); 123 ITRACE(ip1); 124 125 /* 126 * Unlock dp1 and lock dp2 if they are different. 127 */ 128 129 if (diff_dirs) { 130 xfs_iunlock_map_shared(dp1, lock_mode); 131 lock_mode = xfs_ilock_map_shared(dp2); 132 } 133 134 error = xfs_dir_lookup_int(XFS_ITOBHV(dp2), lock_mode, 135 vname2, &inum2, &ip2); 136 if (error == ENOENT) { /* target does not need to exist. */ 137 inum2 = 0; 138 } else if (error) { 139 /* 140 * If dp2 and dp1 are the same, the next line unlocks dp1. 141 * Got it? 142 */ 143 xfs_iunlock_map_shared(dp2, lock_mode); 144 IRELE (ip1); 145 return error; 146 } else { 147 ITRACE(ip2); 148 } 149 150 /* 151 * i_tab contains a list of pointers to inodes. We initialize 152 * the table here & we'll sort it. We will then use it to 153 * order the acquisition of the inode locks. 154 * 155 * Note that the table may contain duplicates. e.g., dp1 == dp2. 156 */ 157 i_tab[0] = dp1; 158 i_tab[1] = dp2; 159 i_tab[2] = ip1; 160 if (inum2 == 0) { 161 *num_inodes = 3; 162 i_tab[3] = NULL; 163 } else { 164 *num_inodes = 4; 165 i_tab[3] = ip2; 166 } 167 168 /* 169 * Sort the elements via bubble sort. (Remember, there are at 170 * most 4 elements to sort, so this is adequate.) 171 */ 172 for (i=0; i < *num_inodes; i++) { 173 for (j=1; j < *num_inodes; j++) { 174 if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) { 175 temp = i_tab[j]; 176 i_tab[j] = i_tab[j-1]; 177 i_tab[j-1] = temp; 178 } 179 } 180 } 181 182 /* 183 * We have dp2 locked. If it isn't first, unlock it. 184 * If it is first, tell xfs_lock_inodes so it can skip it 185 * when locking. if dp1 == dp2, xfs_lock_inodes will skip both 186 * since they are equal. xfs_lock_inodes needs all these inodes 187 * so that it can unlock and retry if there might be a dead-lock 188 * potential with the log. 189 */ 190 191 if (i_tab[0] == dp2 && lock_mode == XFS_ILOCK_SHARED) { 192#ifdef DEBUG 193 xfs_rename_skip++; 194#endif 195 xfs_lock_inodes(i_tab, *num_inodes, 1, XFS_ILOCK_SHARED); 196 } else { 197#ifdef DEBUG 198 xfs_rename_nskip++; 199#endif 200 xfs_iunlock_map_shared(dp2, lock_mode); 201 xfs_lock_inodes(i_tab, *num_inodes, 0, XFS_ILOCK_SHARED); 202 } 203 204 /* 205 * Set the return value. Null out any unused entries in i_tab. 206 */ 207 *ipp1 = *ipp2 = NULL; 208 for (i=0; i < *num_inodes; i++) { 209 if (i_tab[i]->i_ino == inum1) { 210 *ipp1 = i_tab[i]; 211 } 212 if (i_tab[i]->i_ino == inum2) { 213 *ipp2 = i_tab[i]; 214 } 215 } 216 for (;i < 4; i++) { 217 i_tab[i] = NULL; 218 } 219 return 0; 220} 221 222/* 223 * xfs_rename 224 */ 225int 226xfs_rename( 227 bhv_desc_t *src_dir_bdp, 228 vname_t *src_vname, 229 xfs_vnode_t *target_dir_vp, 230 vname_t *target_vname, 231 cred_t *credp) 232{ 233 xfs_trans_t *tp; 234 xfs_inode_t *src_dp, *target_dp, *src_ip, *target_ip; 235 xfs_mount_t *mp; 236 int new_parent; /* moving to a new dir */ 237 int src_is_directory; /* src_name is a directory */ 238 int error; 239 xfs_bmap_free_t free_list; 240 xfs_fsblock_t first_block; 241 int cancel_flags; 242 int committed; 243 xfs_inode_t *inodes[4]; 244 int target_ip_dropped = 0; /* dropped target_ip link? */ 245 xfs_vnode_t *src_dir_vp; 246 int spaceres; 247 int target_link_zero = 0; 248 int num_inodes; 249 char *src_name = VNAME(src_vname); 250 char *target_name = VNAME(target_vname); 251 int src_namelen = VNAMELEN(src_vname); 252 int target_namelen = VNAMELEN(target_vname); 253 254 src_dir_vp = BHV_TO_VNODE(src_dir_bdp); 255 vn_trace_entry(src_dir_vp, "xfs_rename", (inst_t *)__return_address); 256 vn_trace_entry(target_dir_vp, "xfs_rename", (inst_t *)__return_address); 257 258 /* 259 * Find the XFS behavior descriptor for the target directory 260 * vnode since it was not handed to us. 261 */ 262 target_dp = xfs_vtoi(target_dir_vp); 263 if (target_dp == NULL) { 264 return XFS_ERROR(EXDEV); 265 } 266 267 src_dp = XFS_BHVTOI(src_dir_bdp); 268 mp = src_dp->i_mount; 269 270 if (DM_EVENT_ENABLED(src_dir_vp->v_vfsp, src_dp, DM_EVENT_RENAME) || 271 DM_EVENT_ENABLED(target_dir_vp->v_vfsp, 272 target_dp, DM_EVENT_RENAME)) { 273 error = XFS_SEND_NAMESP(mp, DM_EVENT_RENAME, 274 src_dir_vp, DM_RIGHT_NULL, 275 target_dir_vp, DM_RIGHT_NULL, 276 src_name, target_name, 277 0, 0, 0); 278 if (error) { 279 return error; 280 } 281 } 282 /* Return through std_return after this point. */ 283 284 /* 285 * Lock all the participating inodes. Depending upon whether 286 * the target_name exists in the target directory, and 287 * whether the target directory is the same as the source 288 * directory, we can lock from 2 to 4 inodes. 289 * xfs_lock_for_rename() will return ENOENT if src_name 290 * does not exist in the source directory. 291 */ 292 tp = NULL; 293 error = xfs_lock_for_rename(src_dp, target_dp, src_vname, 294 target_vname, &src_ip, &target_ip, inodes, 295 &num_inodes); 296 297 if (error) { 298 /* 299 * We have nothing locked, no inode references, and 300 * no transaction, so just get out. 301 */ 302 goto std_return; 303 } 304 305 ASSERT(src_ip != NULL); 306 307 if ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR) { 308 /* 309 * Check for link count overflow on target_dp 310 */ 311 if (target_ip == NULL && (src_dp != target_dp) && 312 target_dp->i_d.di_nlink >= XFS_MAXLINK) { 313 error = XFS_ERROR(EMLINK); 314 xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED); 315 goto rele_return; 316 } 317 } 318 319 new_parent = (src_dp != target_dp); 320 src_is_directory = ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR); 321 322 /* 323 * Drop the locks on our inodes so that we can start the transaction. 324 */ 325 xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED); 326 327 XFS_BMAP_INIT(&free_list, &first_block); 328 tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME); 329 cancel_flags = XFS_TRANS_RELEASE_LOG_RES; 330 spaceres = XFS_RENAME_SPACE_RES(mp, target_namelen); 331 error = xfs_trans_reserve(tp, spaceres, XFS_RENAME_LOG_RES(mp), 0, 332 XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT); 333 if (error == ENOSPC) { 334 spaceres = 0; 335 error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0, 336 XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT); 337 } 338 if (error) { 339 xfs_trans_cancel(tp, 0); 340 goto rele_return; 341 } 342 343 /* 344 * Attach the dquots to the inodes 345 */ 346 if ((error = XFS_QM_DQVOPRENAME(mp, inodes))) { 347 xfs_trans_cancel(tp, cancel_flags); 348 goto rele_return; 349 } 350 351 /* 352 * Reacquire the inode locks we dropped above. 353 */ 354 xfs_lock_inodes(inodes, num_inodes, 0, XFS_ILOCK_EXCL); 355 356 /* 357 * Join all the inodes to the transaction. From this point on, 358 * we can rely on either trans_commit or trans_cancel to unlock 359 * them. Note that we need to add a vnode reference to the 360 * directories since trans_commit & trans_cancel will decrement 361 * them when they unlock the inodes. Also, we need to be careful 362 * not to add an inode to the transaction more than once. 363 */ 364 VN_HOLD(src_dir_vp); 365 xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL); 366 if (new_parent) { 367 VN_HOLD(target_dir_vp); 368 xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL); 369 } 370 if ((src_ip != src_dp) && (src_ip != target_dp)) { 371 xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL); 372 } 373 if ((target_ip != NULL) && 374 (target_ip != src_ip) && 375 (target_ip != src_dp) && 376 (target_ip != target_dp)) { 377 xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL); 378 } 379 380 /* 381 * Set up the target. 382 */ 383 if (target_ip == NULL) { 384 /* 385 * If there's no space reservation, check the entry will 386 * fit before actually inserting it. 387 */ 388 if (spaceres == 0 && 389 (error = XFS_DIR_CANENTER(mp, tp, target_dp, target_name, 390 target_namelen))) { 391 goto error_return; 392 } 393 /* 394 * If target does not exist and the rename crosses 395 * directories, adjust the target directory link count 396 * to account for the ".." reference from the new entry. 397 */ 398 error = XFS_DIR_CREATENAME(mp, tp, target_dp, target_name, 399 target_namelen, src_ip->i_ino, 400 &first_block, &free_list, spaceres); 401 if (error == ENOSPC) { 402 goto error_return; 403 } 404 if (error) { 405 goto abort_return; 406 } 407 xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); 408 409 if (new_parent && src_is_directory) { 410 error = xfs_bumplink(tp, target_dp); 411 if (error) { 412 goto abort_return; 413 } 414 } 415 } else { /* target_ip != NULL */ 416 417 /* 418 * If target exists and it's a directory, check that both 419 * target and source are directories and that target can be 420 * destroyed, or that neither is a directory. 421 */ 422 if ((target_ip->i_d.di_mode & S_IFMT) == S_IFDIR) { 423 /* 424 * Make sure target dir is empty. 425 */ 426 if (!(XFS_DIR_ISEMPTY(target_ip->i_mount, target_ip)) || 427 (target_ip->i_d.di_nlink > 2)) { 428 error = XFS_ERROR(EEXIST); 429 goto error_return; 430 } 431 } 432 433 /* 434 * Link the source inode under the target name. 435 * If the source inode is a directory and we are moving 436 * it across directories, its ".." entry will be 437 * inconsistent until we replace that down below. 438 * 439 * In case there is already an entry with the same 440 * name at the destination directory, remove it first. 441 */ 442 error = XFS_DIR_REPLACE(mp, tp, target_dp, target_name, 443 target_namelen, src_ip->i_ino, &first_block, 444 &free_list, spaceres); 445 if (error) { 446 goto abort_return; 447 } 448 xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); 449 450 /* 451 * Decrement the link count on the target since the target 452 * dir no longer points to it. 453 */ 454 error = xfs_droplink(tp, target_ip); 455 if (error) { 456 goto abort_return; 457 } 458 target_ip_dropped = 1; 459 460 if (src_is_directory) { 461 /* 462 * Drop the link from the old "." entry. 463 */ 464 error = xfs_droplink(tp, target_ip); 465 if (error) { 466 goto abort_return; 467 } 468 } 469 470 /* Do this test while we still hold the locks */ 471 target_link_zero = (target_ip)->i_d.di_nlink==0; 472 473 } /* target_ip != NULL */ 474 475 /* 476 * Remove the source. 477 */ 478 if (new_parent && src_is_directory) { 479 480 /* 481 * Rewrite the ".." entry to point to the new 482 * directory. 483 */ 484 error = XFS_DIR_REPLACE(mp, tp, src_ip, "..", 2, 485 target_dp->i_ino, &first_block, 486 &free_list, spaceres); 487 ASSERT(error != EEXIST); 488 if (error) { 489 goto abort_return; 490 } 491 xfs_ichgtime(src_ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); 492 493 } else { 494 /* 495 * We always want to hit the ctime on the source inode. 496 * We do it in the if clause above for the 'new_parent && 497 * src_is_directory' case, and here we get all the other 498 * cases. This isn't strictly required by the standards 499 * since the source inode isn't really being changed, 500 * but old unix file systems did it and some incremental 501 * backup programs won't work without it. 502 */ 503 xfs_ichgtime(src_ip, XFS_ICHGTIME_CHG); 504 } 505 506 /* 507 * Adjust the link count on src_dp. This is necessary when 508 * renaming a directory, either within one parent when 509 * the target existed, or across two parent directories. 510 */ 511 if (src_is_directory && (new_parent || target_ip != NULL)) { 512 513 /* 514 * Decrement link count on src_directory since the 515 * entry that's moved no longer points to it. 516 */ 517 error = xfs_droplink(tp, src_dp); 518 if (error) { 519 goto abort_return; 520 } 521 } 522 523 error = XFS_DIR_REMOVENAME(mp, tp, src_dp, src_name, src_namelen, 524 src_ip->i_ino, &first_block, &free_list, spaceres); 525 if (error) { 526 goto abort_return; 527 } 528 xfs_ichgtime(src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); 529 530 /* 531 * Update the generation counts on all the directory inodes 532 * that we're modifying. 533 */ 534 src_dp->i_gen++; 535 xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE); 536 537 if (new_parent) { 538 target_dp->i_gen++; 539 xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE); 540 } 541 542 /* 543 * If there was a target inode, take an extra reference on 544 * it here so that it doesn't go to xfs_inactive() from 545 * within the commit. 546 */ 547 if (target_ip != NULL) { 548 IHOLD(target_ip); 549 } 550 551 /* 552 * If this is a synchronous mount, make sure that the 553 * rename transaction goes to disk before returning to 554 * the user. 555 */ 556 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) { 557 xfs_trans_set_sync(tp); 558 } 559 560 /* 561 * Take refs. for vop_link_removed calls below. No need to worry 562 * about directory refs. because the caller holds them. 563 * 564 * Do holds before the xfs_bmap_finish since it might rele them down 565 * to zero. 566 */ 567 568 if (target_ip_dropped) 569 IHOLD(target_ip); 570 IHOLD(src_ip); 571 572 error = xfs_bmap_finish(&tp, &free_list, first_block, &committed); 573 if (error) { 574 xfs_bmap_cancel(&free_list); 575 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | 576 XFS_TRANS_ABORT)); 577 if (target_ip != NULL) { 578 IRELE(target_ip); 579 } 580 if (target_ip_dropped) { 581 IRELE(target_ip); 582 } 583 IRELE(src_ip); 584 goto std_return; 585 } 586 587 /* 588 * trans_commit will unlock src_ip, target_ip & decrement 589 * the vnode references. 590 */ 591 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL); 592 if (target_ip != NULL) { 593 xfs_refcache_purge_ip(target_ip); 594 IRELE(target_ip); 595 } 596 /* 597 * Let interposed file systems know about removed links. 598 */ 599 if (target_ip_dropped) { 600 XVOP_LINK_REMOVED(XFS_ITOV(target_ip), target_dir_vp, 601 target_link_zero); 602 IRELE(target_ip); 603 } 604 605 IRELE(src_ip); 606 607 /* Fall through to std_return with error = 0 or errno from 608 * xfs_trans_commit */ 609std_return: 610 if (DM_EVENT_ENABLED(src_dir_vp->v_vfsp, src_dp, DM_EVENT_POSTRENAME) || 611 DM_EVENT_ENABLED(target_dir_vp->v_vfsp, 612 target_dp, DM_EVENT_POSTRENAME)) { 613 (void) XFS_SEND_NAMESP (mp, DM_EVENT_POSTRENAME, 614 src_dir_vp, DM_RIGHT_NULL, 615 target_dir_vp, DM_RIGHT_NULL, 616 src_name, target_name, 617 0, error, 0); 618 } 619 return error; 620 621 abort_return: 622 cancel_flags |= XFS_TRANS_ABORT; 623 /* FALLTHROUGH */ 624 error_return: 625 xfs_bmap_cancel(&free_list); 626 xfs_trans_cancel(tp, cancel_flags); 627 goto std_return; 628 629 rele_return: 630 IRELE(src_ip); 631 if (target_ip != NULL) { 632 IRELE(target_ip); 633 } 634 goto std_return; 635} 636 637