1 /* 2 * Copyright (c) 2007-2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sys/vfs/hammer/hammer_object.c,v 1.97 2008/09/23 22:28:56 dillon Exp $ 35 */ 36 37 #include "hammer.h" 38 39 static int hammer_mem_lookup(hammer_cursor_t cursor); 40 static void hammer_mem_first(hammer_cursor_t cursor); 41 static int hammer_frontend_trunc_callback(hammer_record_t record, 42 void *data __unused); 43 static int hammer_bulk_scan_callback(hammer_record_t record, void *data); 44 static int hammer_record_needs_overwrite_delete(hammer_record_t record); 45 static int hammer_delete_general(hammer_cursor_t cursor, hammer_inode_t ip, 46 hammer_btree_leaf_elm_t leaf); 47 48 struct rec_trunc_info { 49 u_int16_t rec_type; 50 int64_t trunc_off; 51 }; 52 53 struct hammer_bulk_info { 54 hammer_record_t record; 55 struct hammer_btree_leaf_elm leaf; 56 }; 57 58 /* 59 * Red-black tree support. Comparison code for insertion. 60 */ 61 static int 62 hammer_rec_rb_compare(hammer_record_t rec1, hammer_record_t rec2) 63 { 64 if (rec1->leaf.base.rec_type < rec2->leaf.base.rec_type) 65 return(-1); 66 if (rec1->leaf.base.rec_type > rec2->leaf.base.rec_type) 67 return(1); 68 69 if (rec1->leaf.base.key < rec2->leaf.base.key) 70 return(-1); 71 if (rec1->leaf.base.key > rec2->leaf.base.key) 72 return(1); 73 74 /* 75 * For search & insertion purposes records deleted by the 76 * frontend or deleted/committed by the backend are silently 77 * ignored. Otherwise pipelined insertions will get messed 78 * up. 79 * 80 * rec1 is greater then rec2 if rec1 is marked deleted. 81 * rec1 is less then rec2 if rec2 is marked deleted. 82 * 83 * Multiple deleted records may be present, do not return 0 84 * if both are marked deleted. 85 */ 86 if (rec1->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE | 87 HAMMER_RECF_COMMITTED)) { 88 return(1); 89 } 90 if (rec2->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE | 91 HAMMER_RECF_COMMITTED)) { 92 return(-1); 93 } 94 95 return(0); 96 } 97 98 /* 99 * Basic record comparison code similar to hammer_btree_cmp(). 100 */ 101 static int 102 hammer_rec_cmp(hammer_base_elm_t elm, hammer_record_t rec) 103 { 104 if (elm->rec_type < rec->leaf.base.rec_type) 105 return(-3); 106 if (elm->rec_type > rec->leaf.base.rec_type) 107 return(3); 108 109 if (elm->key < rec->leaf.base.key) 110 return(-2); 111 if (elm->key > rec->leaf.base.key) 112 return(2); 113 114 /* 115 * Never match against an item deleted by the frontend 116 * or backend, or committed by the backend. 117 * 118 * elm is less then rec if rec is marked deleted. 119 */ 120 if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE | 121 HAMMER_RECF_COMMITTED)) { 122 return(-1); 123 } 124 return(0); 125 } 126 127 /* 128 * Ranged scan to locate overlapping record(s). This is used by 129 * hammer_ip_get_bulk() to locate an overlapping record. We have 130 * to use a ranged scan because the keys for data records with the 131 * same file base offset can be different due to differing data_len's. 132 * 133 * NOTE: The base file offset of a data record is (key - data_len), not (key). 134 */ 135 static int 136 hammer_rec_overlap_cmp(hammer_record_t rec, void *data) 137 { 138 struct hammer_bulk_info *info = data; 139 hammer_btree_leaf_elm_t leaf = &info->leaf; 140 141 if (rec->leaf.base.rec_type < leaf->base.rec_type) 142 return(-3); 143 if (rec->leaf.base.rec_type > leaf->base.rec_type) 144 return(3); 145 146 /* 147 * Overlap compare 148 */ 149 if (leaf->base.rec_type == HAMMER_RECTYPE_DATA) { 150 /* rec_beg >= leaf_end */ 151 if (rec->leaf.base.key - rec->leaf.data_len >= leaf->base.key) 152 return(2); 153 /* rec_end <= leaf_beg */ 154 if (rec->leaf.base.key <= leaf->base.key - leaf->data_len) 155 return(-2); 156 } else { 157 if (rec->leaf.base.key < leaf->base.key) 158 return(-2); 159 if (rec->leaf.base.key > leaf->base.key) 160 return(2); 161 } 162 163 /* 164 * We have to return 0 at this point, even if DELETED_FE is set, 165 * because returning anything else will cause the scan to ignore 166 * one of the branches when we really want it to check both. 167 */ 168 return(0); 169 } 170 171 /* 172 * RB_SCAN comparison code for hammer_mem_first(). The argument order 173 * is reversed so the comparison result has to be negated. key_beg and 174 * key_end are both range-inclusive. 175 * 176 * Localized deletions are not cached in-memory. 177 */ 178 static 179 int 180 hammer_rec_scan_cmp(hammer_record_t rec, void *data) 181 { 182 hammer_cursor_t cursor = data; 183 int r; 184 185 r = hammer_rec_cmp(&cursor->key_beg, rec); 186 if (r > 1) 187 return(-1); 188 r = hammer_rec_cmp(&cursor->key_end, rec); 189 if (r < -1) 190 return(1); 191 return(0); 192 } 193 194 /* 195 * This compare function is used when simply looking up key_beg. 196 */ 197 static 198 int 199 hammer_rec_find_cmp(hammer_record_t rec, void *data) 200 { 201 hammer_cursor_t cursor = data; 202 int r; 203 204 r = hammer_rec_cmp(&cursor->key_beg, rec); 205 if (r > 1) 206 return(-1); 207 if (r < -1) 208 return(1); 209 return(0); 210 } 211 212 /* 213 * Locate blocks within the truncation range. Partial blocks do not count. 214 */ 215 static 216 int 217 hammer_rec_trunc_cmp(hammer_record_t rec, void *data) 218 { 219 struct rec_trunc_info *info = data; 220 221 if (rec->leaf.base.rec_type < info->rec_type) 222 return(-1); 223 if (rec->leaf.base.rec_type > info->rec_type) 224 return(1); 225 226 switch(rec->leaf.base.rec_type) { 227 case HAMMER_RECTYPE_DB: 228 /* 229 * DB record key is not beyond the truncation point, retain. 230 */ 231 if (rec->leaf.base.key < info->trunc_off) 232 return(-1); 233 break; 234 case HAMMER_RECTYPE_DATA: 235 /* 236 * DATA record offset start is not beyond the truncation point, 237 * retain. 238 */ 239 if (rec->leaf.base.key - rec->leaf.data_len < info->trunc_off) 240 return(-1); 241 break; 242 default: 243 panic("hammer_rec_trunc_cmp: unexpected record type"); 244 } 245 246 /* 247 * The record start is >= the truncation point, return match, 248 * the record should be destroyed. 249 */ 250 return(0); 251 } 252 253 RB_GENERATE(hammer_rec_rb_tree, hammer_record, rb_node, hammer_rec_rb_compare); 254 255 /* 256 * Allocate a record for the caller to finish filling in. The record is 257 * returned referenced. 258 */ 259 hammer_record_t 260 hammer_alloc_mem_record(hammer_inode_t ip, int data_len) 261 { 262 hammer_record_t record; 263 hammer_mount_t hmp; 264 265 hmp = ip->hmp; 266 ++hammer_count_records; 267 record = kmalloc(sizeof(*record), hmp->m_misc, 268 M_WAITOK | M_ZERO | M_USE_RESERVE); 269 record->flush_state = HAMMER_FST_IDLE; 270 record->ip = ip; 271 record->leaf.base.btype = HAMMER_BTREE_TYPE_RECORD; 272 record->leaf.data_len = data_len; 273 hammer_ref(&record->lock); 274 275 if (data_len) { 276 record->data = kmalloc(data_len, hmp->m_misc, M_WAITOK | M_ZERO); 277 record->flags |= HAMMER_RECF_ALLOCDATA; 278 ++hammer_count_record_datas; 279 } 280 281 return (record); 282 } 283 284 void 285 hammer_wait_mem_record_ident(hammer_record_t record, const char *ident) 286 { 287 while (record->flush_state == HAMMER_FST_FLUSH) { 288 record->flags |= HAMMER_RECF_WANTED; 289 tsleep(record, 0, ident, 0); 290 } 291 } 292 293 /* 294 * Called from the backend, hammer_inode.c, after a record has been 295 * flushed to disk. The record has been exclusively locked by the 296 * caller and interlocked with BE. 297 * 298 * We clean up the state, unlock, and release the record (the record 299 * was referenced by the fact that it was in the HAMMER_FST_FLUSH state). 300 */ 301 void 302 hammer_flush_record_done(hammer_record_t record, int error) 303 { 304 hammer_inode_t target_ip; 305 306 KKASSERT(record->flush_state == HAMMER_FST_FLUSH); 307 KKASSERT(record->flags & HAMMER_RECF_INTERLOCK_BE); 308 309 /* 310 * If an error occured, the backend was unable to sync the 311 * record to its media. Leave the record intact. 312 */ 313 if (error) { 314 hammer_critical_error(record->ip->hmp, record->ip, error, 315 "while flushing record"); 316 } 317 318 --record->flush_group->refs; 319 record->flush_group = NULL; 320 321 /* 322 * Adjust the flush state and dependancy based on success or 323 * failure. 324 */ 325 if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) { 326 if ((target_ip = record->target_ip) != NULL) { 327 TAILQ_REMOVE(&target_ip->target_list, record, 328 target_entry); 329 record->target_ip = NULL; 330 hammer_test_inode(target_ip); 331 } 332 record->flush_state = HAMMER_FST_IDLE; 333 } else { 334 if (record->target_ip) { 335 record->flush_state = HAMMER_FST_SETUP; 336 hammer_test_inode(record->ip); 337 hammer_test_inode(record->target_ip); 338 } else { 339 record->flush_state = HAMMER_FST_IDLE; 340 } 341 } 342 record->flags &= ~HAMMER_RECF_INTERLOCK_BE; 343 344 /* 345 * Cleanup 346 */ 347 if (record->flags & HAMMER_RECF_WANTED) { 348 record->flags &= ~HAMMER_RECF_WANTED; 349 wakeup(record); 350 } 351 hammer_rel_mem_record(record); 352 } 353 354 /* 355 * Release a memory record. Records marked for deletion are immediately 356 * removed from the RB-Tree but otherwise left intact until the last ref 357 * goes away. 358 */ 359 void 360 hammer_rel_mem_record(struct hammer_record *record) 361 { 362 hammer_mount_t hmp; 363 hammer_reserve_t resv; 364 hammer_inode_t ip; 365 hammer_inode_t target_ip; 366 367 hammer_unref(&record->lock); 368 369 if (record->lock.refs == 0) { 370 /* 371 * Upon release of the last reference wakeup any waiters. 372 * The record structure may get destroyed so callers will 373 * loop up and do a relookup. 374 * 375 * WARNING! Record must be removed from RB-TREE before we 376 * might possibly block. hammer_test_inode() can block! 377 */ 378 ip = record->ip; 379 hmp = ip->hmp; 380 381 /* 382 * Upon release of the last reference a record marked deleted 383 * by the front or backend, or committed by the backend, 384 * is destroyed. 385 */ 386 if (record->flags & (HAMMER_RECF_DELETED_FE | 387 HAMMER_RECF_DELETED_BE | 388 HAMMER_RECF_COMMITTED)) { 389 KKASSERT(ip->lock.refs > 0); 390 KKASSERT(record->flush_state != HAMMER_FST_FLUSH); 391 392 /* 393 * target_ip may have zero refs, we have to ref it 394 * to prevent it from being ripped out from under 395 * us. 396 */ 397 if ((target_ip = record->target_ip) != NULL) { 398 TAILQ_REMOVE(&target_ip->target_list, 399 record, target_entry); 400 record->target_ip = NULL; 401 hammer_ref(&target_ip->lock); 402 } 403 404 if (record->flags & HAMMER_RECF_ONRBTREE) { 405 RB_REMOVE(hammer_rec_rb_tree, 406 &record->ip->rec_tree, 407 record); 408 KKASSERT(ip->rsv_recs > 0); 409 --hmp->rsv_recs; 410 --ip->rsv_recs; 411 hmp->rsv_databytes -= record->leaf.data_len; 412 record->flags &= ~HAMMER_RECF_ONRBTREE; 413 414 if (RB_EMPTY(&record->ip->rec_tree)) { 415 record->ip->flags &= ~HAMMER_INODE_XDIRTY; 416 record->ip->sync_flags &= ~HAMMER_INODE_XDIRTY; 417 hammer_test_inode(record->ip); 418 } 419 } 420 421 /* 422 * We must wait for any direct-IO to complete before 423 * we can destroy the record because the bio may 424 * have a reference to it. 425 */ 426 if (record->flags & 427 (HAMMER_RECF_DIRECT_IO | HAMMER_RECF_DIRECT_INVAL)) { 428 hammer_io_direct_wait(record); 429 } 430 431 432 /* 433 * Do this test after removing record from the B-Tree. 434 */ 435 if (target_ip) { 436 hammer_test_inode(target_ip); 437 hammer_rel_inode(target_ip, 0); 438 } 439 440 if (record->flags & HAMMER_RECF_ALLOCDATA) { 441 --hammer_count_record_datas; 442 kfree(record->data, hmp->m_misc); 443 record->flags &= ~HAMMER_RECF_ALLOCDATA; 444 } 445 446 /* 447 * Release the reservation. 448 * 449 * If the record was not committed we can theoretically 450 * undo the reservation. However, doing so might 451 * create weird edge cases with the ordering of 452 * direct writes because the related buffer cache 453 * elements are per-vnode. So we don't try. 454 */ 455 if ((resv = record->resv) != NULL) { 456 /* XXX undo leaf.data_offset,leaf.data_len */ 457 hammer_blockmap_reserve_complete(hmp, resv); 458 record->resv = NULL; 459 } 460 record->data = NULL; 461 --hammer_count_records; 462 kfree(record, hmp->m_misc); 463 } 464 } 465 } 466 467 /* 468 * Record visibility depends on whether the record is being accessed by 469 * the backend or the frontend. Backend tests ignore the frontend delete 470 * flag. Frontend tests do NOT ignore the backend delete/commit flags and 471 * must also check for commit races. 472 * 473 * Return non-zero if the record is visible, zero if it isn't or if it is 474 * deleted. Returns 0 if the record has been comitted (unless the special 475 * delete-visibility flag is set). A committed record must be located 476 * via the media B-Tree. Returns non-zero if the record is good. 477 * 478 * If HAMMER_CURSOR_DELETE_VISIBILITY is set we allow deleted memory 479 * records to be returned. This is so pending deletions are detected 480 * when using an iterator to locate an unused hash key, or when we need 481 * to locate historical records on-disk to destroy. 482 */ 483 static __inline 484 int 485 hammer_ip_iterate_mem_good(hammer_cursor_t cursor, hammer_record_t record) 486 { 487 if (cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) 488 return(1); 489 if (cursor->flags & HAMMER_CURSOR_BACKEND) { 490 if (record->flags & (HAMMER_RECF_DELETED_BE | 491 HAMMER_RECF_COMMITTED)) { 492 return(0); 493 } 494 } else { 495 if (record->flags & (HAMMER_RECF_DELETED_FE | 496 HAMMER_RECF_DELETED_BE | 497 HAMMER_RECF_COMMITTED)) { 498 return(0); 499 } 500 } 501 return(1); 502 } 503 504 /* 505 * This callback is used as part of the RB_SCAN function for in-memory 506 * records. We terminate it (return -1) as soon as we get a match. 507 * 508 * This routine is used by frontend code. 509 * 510 * The primary compare code does not account for ASOF lookups. This 511 * code handles that case as well as a few others. 512 */ 513 static 514 int 515 hammer_rec_scan_callback(hammer_record_t rec, void *data) 516 { 517 hammer_cursor_t cursor = data; 518 519 /* 520 * We terminate on success, so this should be NULL on entry. 521 */ 522 KKASSERT(cursor->iprec == NULL); 523 524 /* 525 * Skip if the record was marked deleted or committed. 526 */ 527 if (hammer_ip_iterate_mem_good(cursor, rec) == 0) 528 return(0); 529 530 /* 531 * Skip if not visible due to our as-of TID 532 */ 533 if (cursor->flags & HAMMER_CURSOR_ASOF) { 534 if (cursor->asof < rec->leaf.base.create_tid) 535 return(0); 536 if (rec->leaf.base.delete_tid && 537 cursor->asof >= rec->leaf.base.delete_tid) { 538 return(0); 539 } 540 } 541 542 /* 543 * ref the record. The record is protected from backend B-Tree 544 * interactions by virtue of the cursor's IP lock. 545 */ 546 hammer_ref(&rec->lock); 547 548 /* 549 * The record may have been deleted or committed while we 550 * were blocked. XXX remove? 551 */ 552 if (hammer_ip_iterate_mem_good(cursor, rec) == 0) { 553 hammer_rel_mem_record(rec); 554 return(0); 555 } 556 557 /* 558 * Set the matching record and stop the scan. 559 */ 560 cursor->iprec = rec; 561 return(-1); 562 } 563 564 565 /* 566 * Lookup an in-memory record given the key specified in the cursor. Works 567 * just like hammer_btree_lookup() but operates on an inode's in-memory 568 * record list. 569 * 570 * The lookup must fail if the record is marked for deferred deletion. 571 * 572 * The API for mem/btree_lookup() does not mess with the ATE/EOF bits. 573 */ 574 static 575 int 576 hammer_mem_lookup(hammer_cursor_t cursor) 577 { 578 KKASSERT(cursor->ip); 579 if (cursor->iprec) { 580 hammer_rel_mem_record(cursor->iprec); 581 cursor->iprec = NULL; 582 } 583 hammer_rec_rb_tree_RB_SCAN(&cursor->ip->rec_tree, hammer_rec_find_cmp, 584 hammer_rec_scan_callback, cursor); 585 586 return (cursor->iprec ? 0 : ENOENT); 587 } 588 589 /* 590 * hammer_mem_first() - locate the first in-memory record matching the 591 * cursor within the bounds of the key range. 592 * 593 * WARNING! API is slightly different from btree_first(). hammer_mem_first() 594 * will set ATEMEM the same as MEMEOF, and does not return any error. 595 */ 596 static 597 void 598 hammer_mem_first(hammer_cursor_t cursor) 599 { 600 hammer_inode_t ip; 601 602 ip = cursor->ip; 603 KKASSERT(ip != NULL); 604 605 if (cursor->iprec) { 606 hammer_rel_mem_record(cursor->iprec); 607 cursor->iprec = NULL; 608 } 609 hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_scan_cmp, 610 hammer_rec_scan_callback, cursor); 611 612 if (cursor->iprec) 613 cursor->flags &= ~(HAMMER_CURSOR_MEMEOF | HAMMER_CURSOR_ATEMEM); 614 else 615 cursor->flags |= HAMMER_CURSOR_MEMEOF | HAMMER_CURSOR_ATEMEM; 616 } 617 618 /************************************************************************ 619 * HAMMER IN-MEMORY RECORD FUNCTIONS * 620 ************************************************************************ 621 * 622 * These functions manipulate in-memory records. Such records typically 623 * exist prior to being committed to disk or indexed via the on-disk B-Tree. 624 */ 625 626 /* 627 * Add a directory entry (dip,ncp) which references inode (ip). 628 * 629 * Note that the low 32 bits of the namekey are set temporarily to create 630 * a unique in-memory record, and may be modified a second time when the 631 * record is synchronized to disk. In particular, the low 32 bits cannot be 632 * all 0's when synching to disk, which is not handled here. 633 * 634 * NOTE: bytes does not include any terminating \0 on name, and name might 635 * not be terminated. 636 */ 637 int 638 hammer_ip_add_directory(struct hammer_transaction *trans, 639 struct hammer_inode *dip, const char *name, int bytes, 640 struct hammer_inode *ip) 641 { 642 struct hammer_cursor cursor; 643 hammer_record_t record; 644 int error; 645 u_int32_t max_iterations; 646 647 record = hammer_alloc_mem_record(dip, HAMMER_ENTRY_SIZE(bytes)); 648 649 record->type = HAMMER_MEM_RECORD_ADD; 650 record->leaf.base.localization = dip->obj_localization + 651 HAMMER_LOCALIZE_MISC; 652 record->leaf.base.obj_id = dip->obj_id; 653 record->leaf.base.key = hammer_directory_namekey(dip, name, bytes, 654 &max_iterations); 655 record->leaf.base.rec_type = HAMMER_RECTYPE_DIRENTRY; 656 record->leaf.base.obj_type = ip->ino_leaf.base.obj_type; 657 record->data->entry.obj_id = ip->obj_id; 658 record->data->entry.localization = ip->obj_localization; 659 bcopy(name, record->data->entry.name, bytes); 660 661 ++ip->ino_data.nlinks; 662 ip->ino_data.ctime = trans->time; 663 hammer_modify_inode(ip, HAMMER_INODE_DDIRTY); 664 665 /* 666 * Find an unused namekey. Both the in-memory record tree and 667 * the B-Tree are checked. We do not want historically deleted 668 * names to create a collision as our iteration space may be limited, 669 * and since create_tid wouldn't match anyway an ASOF search 670 * must be used to locate collisions. 671 * 672 * delete-visibility is set so pending deletions do not give us 673 * a false-negative on our ability to use an iterator. 674 * 675 * The iterator must not rollover the key. Directory keys only 676 * use the positive key space. 677 */ 678 hammer_init_cursor(trans, &cursor, &dip->cache[1], dip); 679 cursor.key_beg = record->leaf.base; 680 cursor.flags |= HAMMER_CURSOR_ASOF; 681 cursor.flags |= HAMMER_CURSOR_DELETE_VISIBILITY; 682 cursor.asof = ip->obj_asof; 683 684 while (hammer_ip_lookup(&cursor) == 0) { 685 ++record->leaf.base.key; 686 KKASSERT(record->leaf.base.key > 0); 687 cursor.key_beg.key = record->leaf.base.key; 688 if (--max_iterations == 0) { 689 hammer_rel_mem_record(record); 690 error = ENOSPC; 691 goto failed; 692 } 693 } 694 695 /* 696 * The target inode and the directory entry are bound together. 697 */ 698 record->target_ip = ip; 699 record->flush_state = HAMMER_FST_SETUP; 700 TAILQ_INSERT_TAIL(&ip->target_list, record, target_entry); 701 702 /* 703 * The inode now has a dependancy and must be taken out of the idle 704 * state. An inode not in an idle state is given an extra reference. 705 * 706 * When transitioning to a SETUP state flag for an automatic reflush 707 * when the dependancies are disposed of if someone is waiting on 708 * the inode. 709 */ 710 if (ip->flush_state == HAMMER_FST_IDLE) { 711 hammer_ref(&ip->lock); 712 ip->flush_state = HAMMER_FST_SETUP; 713 if (ip->flags & HAMMER_INODE_FLUSHW) 714 ip->flags |= HAMMER_INODE_REFLUSH; 715 } 716 error = hammer_mem_add(record); 717 if (error == 0) { 718 dip->ino_data.mtime = trans->time; 719 hammer_modify_inode(dip, HAMMER_INODE_MTIME); 720 } 721 failed: 722 hammer_done_cursor(&cursor); 723 return(error); 724 } 725 726 /* 727 * Delete the directory entry and update the inode link count. The 728 * cursor must be seeked to the directory entry record being deleted. 729 * 730 * The related inode should be share-locked by the caller. The caller is 731 * on the frontend. It could also be NULL indicating that the directory 732 * entry being removed has no related inode. 733 * 734 * This function can return EDEADLK requiring the caller to terminate 735 * the cursor, any locks, wait on the returned record, and retry. 736 */ 737 int 738 hammer_ip_del_directory(struct hammer_transaction *trans, 739 hammer_cursor_t cursor, struct hammer_inode *dip, 740 struct hammer_inode *ip) 741 { 742 hammer_record_t record; 743 int error; 744 745 if (hammer_cursor_inmem(cursor)) { 746 /* 747 * In-memory (unsynchronized) records can simply be freed. 748 * 749 * Even though the HAMMER_RECF_DELETED_FE flag is ignored 750 * by the backend, we must still avoid races against the 751 * backend potentially syncing the record to the media. 752 * 753 * We cannot call hammer_ip_delete_record(), that routine may 754 * only be called from the backend. 755 */ 756 record = cursor->iprec; 757 if (record->flags & (HAMMER_RECF_INTERLOCK_BE | 758 HAMMER_RECF_DELETED_BE | 759 HAMMER_RECF_COMMITTED)) { 760 KKASSERT(cursor->deadlk_rec == NULL); 761 hammer_ref(&record->lock); 762 cursor->deadlk_rec = record; 763 error = EDEADLK; 764 } else { 765 KKASSERT(record->type == HAMMER_MEM_RECORD_ADD); 766 record->flags |= HAMMER_RECF_DELETED_FE; 767 error = 0; 768 } 769 } else { 770 /* 771 * If the record is on-disk we have to queue the deletion by 772 * the record's key. This also causes lookups to skip the 773 * record. 774 */ 775 KKASSERT(dip->flags & 776 (HAMMER_INODE_ONDISK | HAMMER_INODE_DONDISK)); 777 record = hammer_alloc_mem_record(dip, 0); 778 record->type = HAMMER_MEM_RECORD_DEL; 779 record->leaf.base = cursor->leaf->base; 780 781 /* 782 * ip may be NULL, indicating the deletion of a directory 783 * entry which has no related inode. 784 */ 785 record->target_ip = ip; 786 if (ip) { 787 record->flush_state = HAMMER_FST_SETUP; 788 TAILQ_INSERT_TAIL(&ip->target_list, record, 789 target_entry); 790 } else { 791 record->flush_state = HAMMER_FST_IDLE; 792 } 793 794 /* 795 * The inode now has a dependancy and must be taken out of 796 * the idle state. An inode not in an idle state is given 797 * an extra reference. 798 * 799 * When transitioning to a SETUP state flag for an automatic 800 * reflush when the dependancies are disposed of if someone 801 * is waiting on the inode. 802 */ 803 if (ip && ip->flush_state == HAMMER_FST_IDLE) { 804 hammer_ref(&ip->lock); 805 ip->flush_state = HAMMER_FST_SETUP; 806 if (ip->flags & HAMMER_INODE_FLUSHW) 807 ip->flags |= HAMMER_INODE_REFLUSH; 808 } 809 810 error = hammer_mem_add(record); 811 } 812 813 /* 814 * One less link. The file may still be open in the OS even after 815 * all links have gone away. 816 * 817 * We have to terminate the cursor before syncing the inode to 818 * avoid deadlocking against ourselves. XXX this may no longer 819 * be true. 820 * 821 * If nlinks drops to zero and the vnode is inactive (or there is 822 * no vnode), call hammer_inode_unloadable_check() to zonk the 823 * inode. If we don't do this here the inode will not be destroyed 824 * on-media until we unmount. 825 */ 826 if (error == 0) { 827 if (ip) { 828 --ip->ino_data.nlinks; /* do before we might block */ 829 ip->ino_data.ctime = trans->time; 830 } 831 dip->ino_data.mtime = trans->time; 832 hammer_modify_inode(dip, HAMMER_INODE_MTIME); 833 if (ip) { 834 hammer_modify_inode(ip, HAMMER_INODE_DDIRTY); 835 if (ip->ino_data.nlinks == 0 && 836 (ip->vp == NULL || (ip->vp->v_flag & VINACTIVE))) { 837 hammer_done_cursor(cursor); 838 hammer_inode_unloadable_check(ip, 1); 839 hammer_flush_inode(ip, 0); 840 } 841 } 842 843 } 844 return(error); 845 } 846 847 /* 848 * Add a record to an inode. 849 * 850 * The caller must allocate the record with hammer_alloc_mem_record(ip) and 851 * initialize the following additional fields: 852 * 853 * The related inode should be share-locked by the caller. The caller is 854 * on the frontend. 855 * 856 * record->rec.entry.base.base.key 857 * record->rec.entry.base.base.rec_type 858 * record->rec.entry.base.base.data_len 859 * record->data (a copy will be kmalloc'd if it cannot be embedded) 860 */ 861 int 862 hammer_ip_add_record(struct hammer_transaction *trans, hammer_record_t record) 863 { 864 hammer_inode_t ip = record->ip; 865 int error; 866 867 KKASSERT(record->leaf.base.localization != 0); 868 record->leaf.base.obj_id = ip->obj_id; 869 record->leaf.base.obj_type = ip->ino_leaf.base.obj_type; 870 error = hammer_mem_add(record); 871 return(error); 872 } 873 874 /* 875 * Locate a bulk record in-memory. Bulk records allow disk space to be 876 * reserved so the front-end can flush large data writes without having 877 * to queue the BIO to the flusher. Only the related record gets queued 878 * to the flusher. 879 */ 880 881 static hammer_record_t 882 hammer_ip_get_bulk(hammer_inode_t ip, off_t file_offset, int bytes) 883 { 884 struct hammer_bulk_info info; 885 886 bzero(&info, sizeof(info)); 887 info.leaf.base.obj_id = ip->obj_id; 888 info.leaf.base.key = file_offset + bytes; 889 info.leaf.base.create_tid = 0; 890 info.leaf.base.delete_tid = 0; 891 info.leaf.base.rec_type = HAMMER_RECTYPE_DATA; 892 info.leaf.base.obj_type = 0; /* unused */ 893 info.leaf.base.btype = HAMMER_BTREE_TYPE_RECORD; /* unused */ 894 info.leaf.base.localization = ip->obj_localization + /* unused */ 895 HAMMER_LOCALIZE_MISC; 896 info.leaf.data_len = bytes; 897 898 hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_overlap_cmp, 899 hammer_bulk_scan_callback, &info); 900 901 return(info.record); /* may be NULL */ 902 } 903 904 /* 905 * Take records vetted by overlap_cmp. The first non-deleted record 906 * (if any) stops the scan. 907 */ 908 static int 909 hammer_bulk_scan_callback(hammer_record_t record, void *data) 910 { 911 struct hammer_bulk_info *info = data; 912 913 if (record->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE | 914 HAMMER_RECF_COMMITTED)) { 915 return(0); 916 } 917 hammer_ref(&record->lock); 918 info->record = record; 919 return(-1); /* stop scan */ 920 } 921 922 /* 923 * Reserve blockmap space placemarked with an in-memory record. 924 * 925 * This routine is called by the frontend in order to be able to directly 926 * flush a buffer cache buffer. The frontend has locked the related buffer 927 * cache buffers and we should be able to manipulate any overlapping 928 * in-memory records. 929 * 930 * The caller is responsible for adding the returned record. 931 */ 932 hammer_record_t 933 hammer_ip_add_bulk(hammer_inode_t ip, off_t file_offset, void *data, int bytes, 934 int *errorp) 935 { 936 hammer_record_t record; 937 hammer_record_t conflict; 938 int zone; 939 940 /* 941 * Deal with conflicting in-memory records. We cannot have multiple 942 * in-memory records for the same base offset without seriously 943 * confusing the backend, including but not limited to the backend 944 * issuing delete-create-delete or create-delete-create sequences 945 * and asserting on the delete_tid being the same as the create_tid. 946 * 947 * If we encounter a record with the backend interlock set we cannot 948 * immediately delete it without confusing the backend. 949 */ 950 while ((conflict = hammer_ip_get_bulk(ip, file_offset, bytes)) !=NULL) { 951 if (conflict->flags & HAMMER_RECF_INTERLOCK_BE) { 952 conflict->flags |= HAMMER_RECF_WANTED; 953 tsleep(conflict, 0, "hmrrc3", 0); 954 } else { 955 conflict->flags |= HAMMER_RECF_DELETED_FE; 956 } 957 hammer_rel_mem_record(conflict); 958 } 959 960 /* 961 * Create a record to cover the direct write. This is called with 962 * the related BIO locked so there should be no possible conflict. 963 * 964 * The backend is responsible for finalizing the space reserved in 965 * this record. 966 * 967 * XXX bytes not aligned, depend on the reservation code to 968 * align the reservation. 969 */ 970 record = hammer_alloc_mem_record(ip, 0); 971 zone = (bytes >= HAMMER_BUFSIZE) ? HAMMER_ZONE_LARGE_DATA_INDEX : 972 HAMMER_ZONE_SMALL_DATA_INDEX; 973 record->resv = hammer_blockmap_reserve(ip->hmp, zone, bytes, 974 &record->leaf.data_offset, 975 errorp); 976 if (record->resv == NULL) { 977 kprintf("hammer_ip_add_bulk: reservation failed\n"); 978 hammer_rel_mem_record(record); 979 return(NULL); 980 } 981 record->type = HAMMER_MEM_RECORD_DATA; 982 record->leaf.base.rec_type = HAMMER_RECTYPE_DATA; 983 record->leaf.base.obj_type = ip->ino_leaf.base.obj_type; 984 record->leaf.base.obj_id = ip->obj_id; 985 record->leaf.base.key = file_offset + bytes; 986 record->leaf.base.localization = ip->obj_localization + 987 HAMMER_LOCALIZE_MISC; 988 record->leaf.data_len = bytes; 989 hammer_crc_set_leaf(data, &record->leaf); 990 KKASSERT(*errorp == 0); 991 return(record); 992 } 993 994 /* 995 * Frontend truncation code. Scan in-memory records only. On-disk records 996 * and records in a flushing state are handled by the backend. The vnops 997 * setattr code will handle the block containing the truncation point. 998 * 999 * Partial blocks are not deleted. 1000 */ 1001 int 1002 hammer_ip_frontend_trunc(struct hammer_inode *ip, off_t file_size) 1003 { 1004 struct rec_trunc_info info; 1005 1006 switch(ip->ino_data.obj_type) { 1007 case HAMMER_OBJTYPE_REGFILE: 1008 info.rec_type = HAMMER_RECTYPE_DATA; 1009 break; 1010 case HAMMER_OBJTYPE_DBFILE: 1011 info.rec_type = HAMMER_RECTYPE_DB; 1012 break; 1013 default: 1014 return(EINVAL); 1015 } 1016 info.trunc_off = file_size; 1017 hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_trunc_cmp, 1018 hammer_frontend_trunc_callback, &info); 1019 return(0); 1020 } 1021 1022 static int 1023 hammer_frontend_trunc_callback(hammer_record_t record, void *data __unused) 1024 { 1025 if (record->flags & HAMMER_RECF_DELETED_FE) 1026 return(0); 1027 if (record->flush_state == HAMMER_FST_FLUSH) 1028 return(0); 1029 KKASSERT((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0); 1030 hammer_ref(&record->lock); 1031 record->flags |= HAMMER_RECF_DELETED_FE; 1032 hammer_rel_mem_record(record); 1033 return(0); 1034 } 1035 1036 /* 1037 * Return 1 if the caller must check for and delete existing records 1038 * before writing out a new data record. 1039 * 1040 * Return 0 if the caller can just insert the record into the B-Tree without 1041 * checking. 1042 */ 1043 static int 1044 hammer_record_needs_overwrite_delete(hammer_record_t record) 1045 { 1046 hammer_inode_t ip = record->ip; 1047 int64_t file_offset; 1048 int r; 1049 1050 if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) 1051 file_offset = record->leaf.base.key; 1052 else 1053 file_offset = record->leaf.base.key - record->leaf.data_len; 1054 r = (file_offset < ip->save_trunc_off); 1055 if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) { 1056 if (ip->save_trunc_off <= record->leaf.base.key) 1057 ip->save_trunc_off = record->leaf.base.key + 1; 1058 } else { 1059 if (ip->save_trunc_off < record->leaf.base.key) 1060 ip->save_trunc_off = record->leaf.base.key; 1061 } 1062 return(r); 1063 } 1064 1065 /* 1066 * Backend code. Sync a record to the media. 1067 */ 1068 int 1069 hammer_ip_sync_record_cursor(hammer_cursor_t cursor, hammer_record_t record) 1070 { 1071 hammer_transaction_t trans = cursor->trans; 1072 int64_t file_offset; 1073 int bytes; 1074 void *bdata; 1075 int error; 1076 int doprop; 1077 1078 KKASSERT(record->flush_state == HAMMER_FST_FLUSH); 1079 KKASSERT(record->flags & HAMMER_RECF_INTERLOCK_BE); 1080 KKASSERT(record->leaf.base.localization != 0); 1081 1082 /* 1083 * Any direct-write related to the record must complete before we 1084 * can sync the record to the on-disk media. 1085 */ 1086 if (record->flags & (HAMMER_RECF_DIRECT_IO | HAMMER_RECF_DIRECT_INVAL)) 1087 hammer_io_direct_wait(record); 1088 1089 /* 1090 * If this is a bulk-data record placemarker there may be an existing 1091 * record on-disk, indicating a data overwrite. If there is the 1092 * on-disk record must be deleted before we can insert our new record. 1093 * 1094 * We've synthesized this record and do not know what the create_tid 1095 * on-disk is, nor how much data it represents. 1096 * 1097 * Keep in mind that (key) for data records is (base_offset + len), 1098 * not (base_offset). Also, we only want to get rid of on-disk 1099 * records since we are trying to sync our in-memory record, call 1100 * hammer_ip_delete_range() with truncating set to 1 to make sure 1101 * it skips in-memory records. 1102 * 1103 * It is ok for the lookup to return ENOENT. 1104 * 1105 * NOTE OPTIMIZATION: sync_trunc_off is used to determine if we have 1106 * to call hammer_ip_delete_range() or not. This also means we must 1107 * update sync_trunc_off() as we write. 1108 */ 1109 if (record->type == HAMMER_MEM_RECORD_DATA && 1110 hammer_record_needs_overwrite_delete(record)) { 1111 file_offset = record->leaf.base.key - record->leaf.data_len; 1112 bytes = (record->leaf.data_len + HAMMER_BUFMASK) & 1113 ~HAMMER_BUFMASK; 1114 KKASSERT((file_offset & HAMMER_BUFMASK) == 0); 1115 error = hammer_ip_delete_range( 1116 cursor, record->ip, 1117 file_offset, file_offset + bytes - 1, 1118 1); 1119 if (error && error != ENOENT) 1120 goto done; 1121 } 1122 1123 /* 1124 * If this is a general record there may be an on-disk version 1125 * that must be deleted before we can insert the new record. 1126 */ 1127 if (record->type == HAMMER_MEM_RECORD_GENERAL) { 1128 error = hammer_delete_general(cursor, record->ip, 1129 &record->leaf); 1130 if (error && error != ENOENT) 1131 goto done; 1132 } 1133 1134 /* 1135 * Setup the cursor. 1136 */ 1137 hammer_normalize_cursor(cursor); 1138 cursor->key_beg = record->leaf.base; 1139 cursor->flags &= ~HAMMER_CURSOR_INITMASK; 1140 cursor->flags |= HAMMER_CURSOR_BACKEND; 1141 cursor->flags &= ~HAMMER_CURSOR_INSERT; 1142 1143 /* 1144 * Records can wind up on-media before the inode itself is on-media. 1145 * Flag the case. 1146 */ 1147 record->ip->flags |= HAMMER_INODE_DONDISK; 1148 1149 /* 1150 * If we are deleting a directory entry an exact match must be 1151 * found on-disk. 1152 */ 1153 if (record->type == HAMMER_MEM_RECORD_DEL) { 1154 error = hammer_btree_lookup(cursor); 1155 if (error == 0) { 1156 KKASSERT(cursor->iprec == NULL); 1157 error = hammer_ip_delete_record(cursor, record->ip, 1158 trans->tid); 1159 if (error == 0) { 1160 record->flags |= HAMMER_RECF_DELETED_BE | 1161 HAMMER_RECF_COMMITTED; 1162 ++record->ip->rec_generation; 1163 } 1164 } 1165 goto done; 1166 } 1167 1168 /* 1169 * We are inserting. 1170 * 1171 * Issue a lookup to position the cursor and locate the cluster. The 1172 * target key should not exist. If we are creating a directory entry 1173 * we may have to iterate the low 32 bits of the key to find an unused 1174 * key. 1175 */ 1176 hammer_sync_lock_sh(trans); 1177 cursor->flags |= HAMMER_CURSOR_INSERT; 1178 error = hammer_btree_lookup(cursor); 1179 if (hammer_debug_inode) 1180 kprintf("DOINSERT LOOKUP %d\n", error); 1181 if (error == 0) { 1182 kprintf("hammer_ip_sync_record: duplicate rec " 1183 "at (%016llx)\n", record->leaf.base.key); 1184 Debugger("duplicate record1"); 1185 error = EIO; 1186 } 1187 #if 0 1188 if (record->type == HAMMER_MEM_RECORD_DATA) 1189 kprintf("sync_record %016llx ---------------- %016llx %d\n", 1190 record->leaf.base.key - record->leaf.data_len, 1191 record->leaf.data_offset, error); 1192 #endif 1193 1194 if (error != ENOENT) 1195 goto done_unlock; 1196 1197 /* 1198 * Allocate the record and data. The result buffers will be 1199 * marked as being modified and further calls to 1200 * hammer_modify_buffer() will result in unneeded UNDO records. 1201 * 1202 * Support zero-fill records (data == NULL and data_len != 0) 1203 */ 1204 if (record->type == HAMMER_MEM_RECORD_DATA) { 1205 /* 1206 * The data portion of a bulk-data record has already been 1207 * committed to disk, we need only adjust the layer2 1208 * statistics in the same transaction as our B-Tree insert. 1209 */ 1210 KKASSERT(record->leaf.data_offset != 0); 1211 error = hammer_blockmap_finalize(trans, 1212 record->resv, 1213 record->leaf.data_offset, 1214 record->leaf.data_len); 1215 } else if (record->data && record->leaf.data_len) { 1216 /* 1217 * Wholely cached record, with data. Allocate the data. 1218 */ 1219 bdata = hammer_alloc_data(trans, record->leaf.data_len, 1220 record->leaf.base.rec_type, 1221 &record->leaf.data_offset, 1222 &cursor->data_buffer, &error); 1223 if (bdata == NULL) 1224 goto done_unlock; 1225 hammer_crc_set_leaf(record->data, &record->leaf); 1226 hammer_modify_buffer(trans, cursor->data_buffer, NULL, 0); 1227 bcopy(record->data, bdata, record->leaf.data_len); 1228 hammer_modify_buffer_done(cursor->data_buffer); 1229 } else { 1230 /* 1231 * Wholely cached record, without data. 1232 */ 1233 record->leaf.data_offset = 0; 1234 record->leaf.data_crc = 0; 1235 } 1236 1237 error = hammer_btree_insert(cursor, &record->leaf, &doprop); 1238 if (hammer_debug_inode && error) 1239 kprintf("BTREE INSERT error %d @ %016llx:%d key %016llx\n", error, cursor->node->node_offset, cursor->index, record->leaf.base.key); 1240 1241 /* 1242 * Our record is on-disk and we normally mark the in-memory version 1243 * as having been committed (and not BE-deleted). 1244 * 1245 * If the record represented a directory deletion but we had to 1246 * sync a valid directory entry to disk due to dependancies, 1247 * we must convert the record to a covering delete so the 1248 * frontend does not have visibility on the synced entry. 1249 */ 1250 if (error == 0) { 1251 if (doprop) { 1252 hammer_btree_do_propagation(cursor, 1253 record->ip->pfsm, 1254 &record->leaf); 1255 } 1256 if (record->flags & HAMMER_RECF_CONVERT_DELETE) { 1257 /* 1258 * Must convert deleted directory entry add 1259 * to a directory entry delete. 1260 */ 1261 KKASSERT(record->type == HAMMER_MEM_RECORD_ADD); 1262 record->flags &= ~HAMMER_RECF_DELETED_FE; 1263 record->type = HAMMER_MEM_RECORD_DEL; 1264 KKASSERT(record->flush_state == HAMMER_FST_FLUSH); 1265 record->flags &= ~HAMMER_RECF_CONVERT_DELETE; 1266 KKASSERT((record->flags & (HAMMER_RECF_COMMITTED | 1267 HAMMER_RECF_DELETED_BE)) == 0); 1268 /* converted record is not yet committed */ 1269 /* hammer_flush_record_done takes care of the rest */ 1270 } else { 1271 /* 1272 * Everything went fine and we are now done with 1273 * this record. 1274 */ 1275 record->flags |= HAMMER_RECF_COMMITTED; 1276 ++record->ip->rec_generation; 1277 } 1278 } else { 1279 if (record->leaf.data_offset) { 1280 hammer_blockmap_free(trans, record->leaf.data_offset, 1281 record->leaf.data_len); 1282 } 1283 } 1284 done_unlock: 1285 hammer_sync_unlock(trans); 1286 done: 1287 return(error); 1288 } 1289 1290 /* 1291 * Add the record to the inode's rec_tree. The low 32 bits of a directory 1292 * entry's key is used to deal with hash collisions in the upper 32 bits. 1293 * A unique 64 bit key is generated in-memory and may be regenerated a 1294 * second time when the directory record is flushed to the on-disk B-Tree. 1295 * 1296 * A referenced record is passed to this function. This function 1297 * eats the reference. If an error occurs the record will be deleted. 1298 * 1299 * A copy of the temporary record->data pointer provided by the caller 1300 * will be made. 1301 */ 1302 int 1303 hammer_mem_add(hammer_record_t record) 1304 { 1305 hammer_mount_t hmp = record->ip->hmp; 1306 1307 /* 1308 * Make a private copy of record->data 1309 */ 1310 if (record->data) 1311 KKASSERT(record->flags & HAMMER_RECF_ALLOCDATA); 1312 1313 /* 1314 * Insert into the RB tree. A unique key should have already 1315 * been selected if this is a directory entry. 1316 */ 1317 if (RB_INSERT(hammer_rec_rb_tree, &record->ip->rec_tree, record)) { 1318 record->flags |= HAMMER_RECF_DELETED_FE; 1319 hammer_rel_mem_record(record); 1320 return (EEXIST); 1321 } 1322 ++hmp->count_newrecords; 1323 ++hmp->rsv_recs; 1324 ++record->ip->rsv_recs; 1325 record->ip->hmp->rsv_databytes += record->leaf.data_len; 1326 record->flags |= HAMMER_RECF_ONRBTREE; 1327 hammer_modify_inode(record->ip, HAMMER_INODE_XDIRTY); 1328 hammer_rel_mem_record(record); 1329 return(0); 1330 } 1331 1332 /************************************************************************ 1333 * HAMMER INODE MERGED-RECORD FUNCTIONS * 1334 ************************************************************************ 1335 * 1336 * These functions augment the B-Tree scanning functions in hammer_btree.c 1337 * by merging in-memory records with on-disk records. 1338 */ 1339 1340 /* 1341 * Locate a particular record either in-memory or on-disk. 1342 * 1343 * NOTE: This is basically a standalone routine, hammer_ip_next() may 1344 * NOT be called to iterate results. 1345 */ 1346 int 1347 hammer_ip_lookup(hammer_cursor_t cursor) 1348 { 1349 int error; 1350 1351 /* 1352 * If the element is in-memory return it without searching the 1353 * on-disk B-Tree 1354 */ 1355 KKASSERT(cursor->ip); 1356 error = hammer_mem_lookup(cursor); 1357 if (error == 0) { 1358 cursor->leaf = &cursor->iprec->leaf; 1359 return(error); 1360 } 1361 if (error != ENOENT) 1362 return(error); 1363 1364 /* 1365 * If the inode has on-disk components search the on-disk B-Tree. 1366 */ 1367 if ((cursor->ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DONDISK)) == 0) 1368 return(error); 1369 error = hammer_btree_lookup(cursor); 1370 if (error == 0) 1371 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_LEAF); 1372 return(error); 1373 } 1374 1375 /* 1376 * Helper for hammer_ip_first()/hammer_ip_next() 1377 * 1378 * NOTE: Both ATEDISK and DISKEOF will be set the same. This sets up 1379 * hammer_ip_first() for calling hammer_ip_next(), and sets up the re-seek 1380 * state if hammer_ip_next() needs to re-seek. 1381 */ 1382 static __inline 1383 int 1384 _hammer_ip_seek_btree(hammer_cursor_t cursor) 1385 { 1386 hammer_inode_t ip = cursor->ip; 1387 int error; 1388 1389 if (ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DONDISK)) { 1390 error = hammer_btree_lookup(cursor); 1391 if (error == ENOENT || error == EDEADLK) { 1392 if (hammer_debug_general & 0x2000) 1393 kprintf("error %d node %p %016llx index %d\n", error, cursor->node, cursor->node->node_offset, cursor->index); 1394 cursor->flags &= ~HAMMER_CURSOR_ATEDISK; 1395 error = hammer_btree_iterate(cursor); 1396 } 1397 if (error == 0) { 1398 cursor->flags &= ~(HAMMER_CURSOR_DISKEOF | 1399 HAMMER_CURSOR_ATEDISK); 1400 } else { 1401 cursor->flags |= HAMMER_CURSOR_DISKEOF | 1402 HAMMER_CURSOR_ATEDISK; 1403 if (error == ENOENT) 1404 error = 0; 1405 } 1406 } else { 1407 cursor->flags |= HAMMER_CURSOR_DISKEOF | HAMMER_CURSOR_ATEDISK; 1408 error = 0; 1409 } 1410 return(error); 1411 } 1412 1413 /* 1414 * Helper for hammer_ip_next() 1415 * 1416 * The caller has determined that the media cursor is further along than the 1417 * memory cursor and must be reseeked after a generation number change. 1418 */ 1419 static 1420 int 1421 _hammer_ip_reseek(hammer_cursor_t cursor) 1422 { 1423 struct hammer_base_elm save; 1424 hammer_btree_elm_t elm; 1425 int error; 1426 int r; 1427 int again = 0; 1428 1429 /* 1430 * Do the re-seek. 1431 */ 1432 kprintf("HAMMER: Debug: re-seeked during scan @ino=%016llx\n", 1433 (long long)cursor->ip->obj_id); 1434 save = cursor->key_beg; 1435 cursor->key_beg = cursor->iprec->leaf.base; 1436 error = _hammer_ip_seek_btree(cursor); 1437 KKASSERT(error == 0); 1438 cursor->key_beg = save; 1439 1440 /* 1441 * If the memory record was previous returned to 1442 * the caller and the media record matches 1443 * (-1/+1: only create_tid differs), then iterate 1444 * the media record to avoid a double result. 1445 */ 1446 if ((cursor->flags & HAMMER_CURSOR_ATEDISK) == 0 && 1447 (cursor->flags & HAMMER_CURSOR_LASTWASMEM)) { 1448 elm = &cursor->node->ondisk->elms[cursor->index]; 1449 r = hammer_btree_cmp(&elm->base, 1450 &cursor->iprec->leaf.base); 1451 if (cursor->flags & HAMMER_CURSOR_ASOF) { 1452 if (r >= -1 && r <= 1) { 1453 kprintf("HAMMER: Debug: iterated after " 1454 "re-seek (asof r=%d)\n", r); 1455 cursor->flags |= HAMMER_CURSOR_ATEDISK; 1456 again = 1; 1457 } 1458 } else { 1459 if (r == 0) { 1460 kprintf("HAMMER: Debug: iterated after " 1461 "re-seek\n"); 1462 cursor->flags |= HAMMER_CURSOR_ATEDISK; 1463 again = 1; 1464 } 1465 } 1466 } 1467 return(again); 1468 } 1469 1470 /* 1471 * Locate the first record within the cursor's key_beg/key_end range, 1472 * restricted to a particular inode. 0 is returned on success, ENOENT 1473 * if no records matched the requested range, or some other error. 1474 * 1475 * When 0 is returned hammer_ip_next() may be used to iterate additional 1476 * records within the requested range. 1477 * 1478 * This function can return EDEADLK, requiring the caller to terminate 1479 * the cursor and try again. 1480 */ 1481 1482 int 1483 hammer_ip_first(hammer_cursor_t cursor) 1484 { 1485 hammer_inode_t ip = cursor->ip; 1486 int error; 1487 1488 KKASSERT(ip != NULL); 1489 1490 /* 1491 * Clean up fields and setup for merged scan 1492 */ 1493 cursor->flags &= ~HAMMER_CURSOR_RETEST; 1494 1495 /* 1496 * Search the in-memory record list (Red-Black tree). Unlike the 1497 * B-Tree search, mem_first checks for records in the range. 1498 * 1499 * This function will setup both ATEMEM and MEMEOF properly for 1500 * the ip iteration. ATEMEM will be set if MEMEOF is set. 1501 */ 1502 hammer_mem_first(cursor); 1503 1504 /* 1505 * Detect generation changes during blockages, including 1506 * blockages which occur on the initial btree search. 1507 */ 1508 cursor->rec_generation = cursor->ip->rec_generation; 1509 1510 /* 1511 * Initial search and result 1512 */ 1513 error = _hammer_ip_seek_btree(cursor); 1514 if (error == 0) 1515 error = hammer_ip_next(cursor); 1516 1517 return (error); 1518 } 1519 1520 /* 1521 * Retrieve the next record in a merged iteration within the bounds of the 1522 * cursor. This call may be made multiple times after the cursor has been 1523 * initially searched with hammer_ip_first(). 1524 * 1525 * There are numerous special cases in this code to deal with races between 1526 * in-memory records and on-media records. 1527 * 1528 * 0 is returned on success, ENOENT if no further records match the 1529 * requested range, or some other error code is returned. 1530 */ 1531 int 1532 hammer_ip_next(hammer_cursor_t cursor) 1533 { 1534 hammer_btree_elm_t elm; 1535 hammer_record_t rec; 1536 hammer_record_t tmprec; 1537 int error; 1538 int r; 1539 1540 again: 1541 /* 1542 * Get the next on-disk record 1543 * 1544 * NOTE: If we deleted the last on-disk record we had scanned 1545 * ATEDISK will be clear and RETEST will be set, forcing 1546 * a call to iterate. The fact that ATEDISK is clear causes 1547 * iterate to re-test the 'current' element. If ATEDISK is 1548 * set, iterate will skip the 'current' element. 1549 */ 1550 error = 0; 1551 if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) { 1552 if (cursor->flags & (HAMMER_CURSOR_ATEDISK | 1553 HAMMER_CURSOR_RETEST)) { 1554 error = hammer_btree_iterate(cursor); 1555 cursor->flags &= ~HAMMER_CURSOR_RETEST; 1556 if (error == 0) { 1557 cursor->flags &= ~HAMMER_CURSOR_ATEDISK; 1558 hammer_cache_node(&cursor->ip->cache[1], 1559 cursor->node); 1560 } else if (error == ENOENT) { 1561 cursor->flags |= HAMMER_CURSOR_DISKEOF | 1562 HAMMER_CURSOR_ATEDISK; 1563 error = 0; 1564 } 1565 } 1566 } 1567 1568 /* 1569 * If the generation changed the backend has deleted or committed 1570 * one or more memory records since our last check. 1571 * 1572 * When this case occurs if the disk cursor is > current memory record 1573 * or the disk cursor is at EOF, we must re-seek the disk-cursor. 1574 * Since the cursor is ahead it must have not yet been eaten (if 1575 * not at eof anyway). (XXX data offset case?) 1576 * 1577 * NOTE: we are not doing a full check here. That will be handled 1578 * later on. 1579 * 1580 * If we have exhausted all memory records we do not have to do any 1581 * further seeks. 1582 */ 1583 while (cursor->rec_generation != cursor->ip->rec_generation && 1584 error == 0 1585 ) { 1586 kprintf("HAMMER: Debug: generation changed during scan @ino=%016llx\n", (long long)cursor->ip->obj_id); 1587 cursor->rec_generation = cursor->ip->rec_generation; 1588 if (cursor->flags & HAMMER_CURSOR_MEMEOF) 1589 break; 1590 if (cursor->flags & HAMMER_CURSOR_DISKEOF) { 1591 r = 1; 1592 } else { 1593 KKASSERT((cursor->flags & HAMMER_CURSOR_ATEDISK) == 0); 1594 elm = &cursor->node->ondisk->elms[cursor->index]; 1595 r = hammer_btree_cmp(&elm->base, 1596 &cursor->iprec->leaf.base); 1597 } 1598 1599 /* 1600 * Do we re-seek the media cursor? 1601 */ 1602 if (r > 0) { 1603 if (_hammer_ip_reseek(cursor)) 1604 goto again; 1605 } 1606 } 1607 1608 /* 1609 * We can now safely get the next in-memory record. We cannot 1610 * block here. 1611 * 1612 * hammer_rec_scan_cmp: Is the record still in our general range, 1613 * (non-inclusive of snapshot exclusions)? 1614 * hammer_rec_scan_callback: Is the record in our snapshot? 1615 */ 1616 tmprec = NULL; 1617 if ((cursor->flags & HAMMER_CURSOR_MEMEOF) == 0) { 1618 /* 1619 * If the current memory record was eaten then get the next 1620 * one. Stale records are skipped. 1621 */ 1622 if (cursor->flags & HAMMER_CURSOR_ATEMEM) { 1623 tmprec = cursor->iprec; 1624 cursor->iprec = NULL; 1625 rec = hammer_rec_rb_tree_RB_NEXT(tmprec); 1626 while (rec) { 1627 if (hammer_rec_scan_cmp(rec, cursor) != 0) 1628 break; 1629 if (hammer_rec_scan_callback(rec, cursor) != 0) 1630 break; 1631 rec = hammer_rec_rb_tree_RB_NEXT(rec); 1632 } 1633 if (cursor->iprec) { 1634 KKASSERT(cursor->iprec == rec); 1635 cursor->flags &= ~HAMMER_CURSOR_ATEMEM; 1636 } else { 1637 cursor->flags |= HAMMER_CURSOR_MEMEOF; 1638 } 1639 cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM; 1640 } 1641 } 1642 1643 /* 1644 * MEMORY RECORD VALIDITY TEST 1645 * 1646 * (We still can't block, which is why tmprec is being held so 1647 * long). 1648 * 1649 * If the memory record is no longer valid we skip it. It may 1650 * have been deleted by the frontend. If it was deleted or 1651 * committed by the backend the generation change re-seeked the 1652 * disk cursor and the record will be present there. 1653 */ 1654 if (error == 0 && (cursor->flags & HAMMER_CURSOR_MEMEOF) == 0) { 1655 KKASSERT(cursor->iprec); 1656 KKASSERT((cursor->flags & HAMMER_CURSOR_ATEMEM) == 0); 1657 if (!hammer_ip_iterate_mem_good(cursor, cursor->iprec)) { 1658 cursor->flags |= HAMMER_CURSOR_ATEMEM; 1659 if (tmprec) 1660 hammer_rel_mem_record(tmprec); 1661 goto again; 1662 } 1663 } 1664 if (tmprec) 1665 hammer_rel_mem_record(tmprec); 1666 1667 /* 1668 * Extract either the disk or memory record depending on their 1669 * relative position. 1670 */ 1671 error = 0; 1672 switch(cursor->flags & (HAMMER_CURSOR_ATEDISK | HAMMER_CURSOR_ATEMEM)) { 1673 case 0: 1674 /* 1675 * Both entries valid. Compare the entries and nominally 1676 * return the first one in the sort order. Numerous cases 1677 * require special attention, however. 1678 */ 1679 elm = &cursor->node->ondisk->elms[cursor->index]; 1680 r = hammer_btree_cmp(&elm->base, &cursor->iprec->leaf.base); 1681 1682 /* 1683 * If the two entries differ only by their key (-2/2) or 1684 * create_tid (-1/1), and are DATA records, we may have a 1685 * nominal match. We have to calculate the base file 1686 * offset of the data. 1687 */ 1688 if (r <= 2 && r >= -2 && r != 0 && 1689 cursor->ip->ino_data.obj_type == HAMMER_OBJTYPE_REGFILE && 1690 cursor->iprec->type == HAMMER_MEM_RECORD_DATA) { 1691 int64_t base1 = elm->leaf.base.key - elm->leaf.data_len; 1692 int64_t base2 = cursor->iprec->leaf.base.key - 1693 cursor->iprec->leaf.data_len; 1694 if (base1 == base2) 1695 r = 0; 1696 } 1697 1698 if (r < 0) { 1699 error = hammer_btree_extract(cursor, 1700 HAMMER_CURSOR_GET_LEAF); 1701 cursor->flags |= HAMMER_CURSOR_ATEDISK; 1702 cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM; 1703 break; 1704 } 1705 1706 /* 1707 * If the entries match exactly the memory entry is either 1708 * an on-disk directory entry deletion or a bulk data 1709 * overwrite. If it is a directory entry deletion we eat 1710 * both entries. 1711 * 1712 * For the bulk-data overwrite case it is possible to have 1713 * visibility into both, which simply means the syncer 1714 * hasn't gotten around to doing the delete+insert sequence 1715 * on the B-Tree. Use the memory entry and throw away the 1716 * on-disk entry. 1717 * 1718 * If the in-memory record is not either of these we 1719 * probably caught the syncer while it was syncing it to 1720 * the media. Since we hold a shared lock on the cursor, 1721 * the in-memory record had better be marked deleted at 1722 * this point. 1723 */ 1724 if (r == 0) { 1725 if (cursor->iprec->type == HAMMER_MEM_RECORD_DEL) { 1726 if ((cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) { 1727 cursor->flags |= HAMMER_CURSOR_ATEDISK; 1728 cursor->flags |= HAMMER_CURSOR_ATEMEM; 1729 goto again; 1730 } 1731 } else if (cursor->iprec->type == HAMMER_MEM_RECORD_DATA) { 1732 if ((cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) { 1733 cursor->flags |= HAMMER_CURSOR_ATEDISK; 1734 } 1735 /* fall through to memory entry */ 1736 } else { 1737 panic("hammer_ip_next: duplicate mem/b-tree entry %p %d %08x", cursor->iprec, cursor->iprec->type, cursor->iprec->flags); 1738 cursor->flags |= HAMMER_CURSOR_ATEMEM; 1739 goto again; 1740 } 1741 } 1742 /* fall through to the memory entry */ 1743 case HAMMER_CURSOR_ATEDISK: 1744 /* 1745 * Only the memory entry is valid. 1746 */ 1747 cursor->leaf = &cursor->iprec->leaf; 1748 cursor->flags |= HAMMER_CURSOR_ATEMEM; 1749 cursor->flags |= HAMMER_CURSOR_LASTWASMEM; 1750 1751 /* 1752 * If the memory entry is an on-disk deletion we should have 1753 * also had found a B-Tree record. If the backend beat us 1754 * to it it would have interlocked the cursor and we should 1755 * have seen the in-memory record marked DELETED_FE. 1756 */ 1757 if (cursor->iprec->type == HAMMER_MEM_RECORD_DEL && 1758 (cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) { 1759 panic("hammer_ip_next: del-on-disk with no b-tree entry iprec %p flags %08x", cursor->iprec, cursor->iprec->flags); 1760 } 1761 break; 1762 case HAMMER_CURSOR_ATEMEM: 1763 /* 1764 * Only the disk entry is valid 1765 */ 1766 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_LEAF); 1767 cursor->flags |= HAMMER_CURSOR_ATEDISK; 1768 cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM; 1769 break; 1770 default: 1771 /* 1772 * Neither entry is valid 1773 * 1774 * XXX error not set properly 1775 */ 1776 cursor->flags &= ~HAMMER_CURSOR_LASTWASMEM; 1777 cursor->leaf = NULL; 1778 error = ENOENT; 1779 break; 1780 } 1781 return(error); 1782 } 1783 1784 /* 1785 * Resolve the cursor->data pointer for the current cursor position in 1786 * a merged iteration. 1787 */ 1788 int 1789 hammer_ip_resolve_data(hammer_cursor_t cursor) 1790 { 1791 hammer_record_t record; 1792 int error; 1793 1794 if (hammer_cursor_inmem(cursor)) { 1795 /* 1796 * The data associated with an in-memory record is usually 1797 * kmalloced, but reserve-ahead data records will have an 1798 * on-disk reference. 1799 * 1800 * NOTE: Reserve-ahead data records must be handled in the 1801 * context of the related high level buffer cache buffer 1802 * to interlock against async writes. 1803 */ 1804 record = cursor->iprec; 1805 cursor->data = record->data; 1806 error = 0; 1807 if (cursor->data == NULL) { 1808 KKASSERT(record->leaf.base.rec_type == 1809 HAMMER_RECTYPE_DATA); 1810 cursor->data = hammer_bread_ext(cursor->trans->hmp, 1811 record->leaf.data_offset, 1812 record->leaf.data_len, 1813 &error, 1814 &cursor->data_buffer); 1815 } 1816 } else { 1817 cursor->leaf = &cursor->node->ondisk->elms[cursor->index].leaf; 1818 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA); 1819 } 1820 return(error); 1821 } 1822 1823 /* 1824 * Backend truncation / record replacement - delete records in range. 1825 * 1826 * Delete all records within the specified range for inode ip. In-memory 1827 * records still associated with the frontend are ignored. 1828 * 1829 * If truncating is non-zero in-memory records associated with the back-end 1830 * are ignored. If truncating is > 1 we can return EWOULDBLOCK. 1831 * 1832 * NOTES: 1833 * 1834 * * An unaligned range will cause new records to be added to cover 1835 * the edge cases. (XXX not implemented yet). 1836 * 1837 * * Replacement via reservations (see hammer_ip_sync_record_cursor()) 1838 * also do not deal with unaligned ranges. 1839 * 1840 * * ran_end is inclusive (e.g. 0,1023 instead of 0,1024). 1841 * 1842 * * Record keys for regular file data have to be special-cased since 1843 * they indicate the end of the range (key = base + bytes). 1844 * 1845 * * This function may be asked to delete ridiculously huge ranges, for 1846 * example if someone truncates or removes a 1TB regular file. We 1847 * must be very careful on restarts and we may have to stop w/ 1848 * EWOULDBLOCK to avoid blowing out the buffer cache. 1849 */ 1850 int 1851 hammer_ip_delete_range(hammer_cursor_t cursor, hammer_inode_t ip, 1852 int64_t ran_beg, int64_t ran_end, int truncating) 1853 { 1854 hammer_transaction_t trans = cursor->trans; 1855 hammer_btree_leaf_elm_t leaf; 1856 int error; 1857 int64_t off; 1858 int64_t tmp64; 1859 1860 #if 0 1861 kprintf("delete_range %p %016llx-%016llx\n", ip, ran_beg, ran_end); 1862 #endif 1863 1864 KKASSERT(trans->type == HAMMER_TRANS_FLS); 1865 retry: 1866 hammer_normalize_cursor(cursor); 1867 cursor->key_beg.localization = ip->obj_localization + 1868 HAMMER_LOCALIZE_MISC; 1869 cursor->key_beg.obj_id = ip->obj_id; 1870 cursor->key_beg.create_tid = 0; 1871 cursor->key_beg.delete_tid = 0; 1872 cursor->key_beg.obj_type = 0; 1873 1874 if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) { 1875 cursor->key_beg.key = ran_beg; 1876 cursor->key_beg.rec_type = HAMMER_RECTYPE_DB; 1877 } else { 1878 /* 1879 * The key in the B-Tree is (base+bytes), so the first possible 1880 * matching key is ran_beg + 1. 1881 */ 1882 cursor->key_beg.key = ran_beg + 1; 1883 cursor->key_beg.rec_type = HAMMER_RECTYPE_DATA; 1884 } 1885 1886 cursor->key_end = cursor->key_beg; 1887 if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DBFILE) { 1888 cursor->key_end.key = ran_end; 1889 } else { 1890 tmp64 = ran_end + MAXPHYS + 1; /* work around GCC-4 bug */ 1891 if (tmp64 < ran_end) 1892 cursor->key_end.key = 0x7FFFFFFFFFFFFFFFLL; 1893 else 1894 cursor->key_end.key = ran_end + MAXPHYS + 1; 1895 } 1896 1897 cursor->asof = ip->obj_asof; 1898 cursor->flags &= ~HAMMER_CURSOR_INITMASK; 1899 cursor->flags |= HAMMER_CURSOR_ASOF; 1900 cursor->flags |= HAMMER_CURSOR_DELETE_VISIBILITY; 1901 cursor->flags |= HAMMER_CURSOR_BACKEND; 1902 cursor->flags |= HAMMER_CURSOR_END_INCLUSIVE; 1903 1904 error = hammer_ip_first(cursor); 1905 1906 /* 1907 * Iterate through matching records and mark them as deleted. 1908 */ 1909 while (error == 0) { 1910 leaf = cursor->leaf; 1911 1912 KKASSERT(leaf->base.delete_tid == 0); 1913 KKASSERT(leaf->base.obj_id == ip->obj_id); 1914 1915 /* 1916 * There may be overlap cases for regular file data. Also 1917 * remember the key for a regular file record is (base + len), 1918 * NOT (base). 1919 * 1920 * Note that do to duplicates (mem & media) allowed by 1921 * DELETE_VISIBILITY, off can wind up less then ran_beg. 1922 */ 1923 if (leaf->base.rec_type == HAMMER_RECTYPE_DATA) { 1924 off = leaf->base.key - leaf->data_len; 1925 /* 1926 * Check the left edge case. We currently do not 1927 * split existing records. 1928 */ 1929 if (off < ran_beg && leaf->base.key > ran_beg) { 1930 panic("hammer left edge case %016llx %d\n", 1931 leaf->base.key, leaf->data_len); 1932 } 1933 1934 /* 1935 * Check the right edge case. Note that the 1936 * record can be completely out of bounds, which 1937 * terminates the search. 1938 * 1939 * base->key is exclusive of the right edge while 1940 * ran_end is inclusive of the right edge. The 1941 * (key - data_len) left boundary is inclusive. 1942 * 1943 * XXX theory-check this test at some point, are 1944 * we missing a + 1 somewhere? Note that ran_end 1945 * could overflow. 1946 */ 1947 if (leaf->base.key - 1 > ran_end) { 1948 if (leaf->base.key - leaf->data_len > ran_end) 1949 break; 1950 panic("hammer right edge case\n"); 1951 } 1952 } else { 1953 off = leaf->base.key; 1954 } 1955 1956 /* 1957 * Delete the record. When truncating we do not delete 1958 * in-memory (data) records because they represent data 1959 * written after the truncation. 1960 * 1961 * This will also physically destroy the B-Tree entry and 1962 * data if the retention policy dictates. The function 1963 * will set HAMMER_CURSOR_RETEST to cause hammer_ip_next() 1964 * to retest the new 'current' element. 1965 */ 1966 if (truncating == 0 || hammer_cursor_ondisk(cursor)) { 1967 error = hammer_ip_delete_record(cursor, ip, trans->tid); 1968 /* 1969 * If we have built up too many meta-buffers we risk 1970 * deadlocking the kernel and must stop. This can 1971 * occur when deleting ridiculously huge files. 1972 * sync_trunc_off is updated so the next cycle does 1973 * not re-iterate records we have already deleted. 1974 * 1975 * This is only done with formal truncations. 1976 */ 1977 if (truncating > 1 && error == 0 && 1978 hammer_flusher_meta_limit(ip->hmp)) { 1979 ip->sync_trunc_off = off; 1980 error = EWOULDBLOCK; 1981 } 1982 } 1983 if (error) 1984 break; 1985 ran_beg = off; /* for restart */ 1986 error = hammer_ip_next(cursor); 1987 } 1988 if (cursor->node) 1989 hammer_cache_node(&ip->cache[1], cursor->node); 1990 1991 if (error == EDEADLK) { 1992 hammer_done_cursor(cursor); 1993 error = hammer_init_cursor(trans, cursor, &ip->cache[1], ip); 1994 if (error == 0) 1995 goto retry; 1996 } 1997 if (error == ENOENT) 1998 error = 0; 1999 return(error); 2000 } 2001 2002 /* 2003 * This backend function deletes the specified record on-disk, similar to 2004 * delete_range but for a specific record. Unlike the exact deletions 2005 * used when deleting a directory entry this function uses an ASOF search 2006 * like delete_range. 2007 * 2008 * This function may be called with ip->obj_asof set for a slave snapshot, 2009 * so don't use it. We always delete non-historical records only. 2010 */ 2011 static int 2012 hammer_delete_general(hammer_cursor_t cursor, hammer_inode_t ip, 2013 hammer_btree_leaf_elm_t leaf) 2014 { 2015 hammer_transaction_t trans = cursor->trans; 2016 int error; 2017 2018 KKASSERT(trans->type == HAMMER_TRANS_FLS); 2019 retry: 2020 hammer_normalize_cursor(cursor); 2021 cursor->key_beg = leaf->base; 2022 cursor->asof = HAMMER_MAX_TID; 2023 cursor->flags &= ~HAMMER_CURSOR_INITMASK; 2024 cursor->flags |= HAMMER_CURSOR_ASOF; 2025 cursor->flags |= HAMMER_CURSOR_BACKEND; 2026 cursor->flags &= ~HAMMER_CURSOR_INSERT; 2027 2028 error = hammer_btree_lookup(cursor); 2029 if (error == 0) { 2030 error = hammer_ip_delete_record(cursor, ip, trans->tid); 2031 } 2032 if (error == EDEADLK) { 2033 hammer_done_cursor(cursor); 2034 error = hammer_init_cursor(trans, cursor, &ip->cache[1], ip); 2035 if (error == 0) 2036 goto retry; 2037 } 2038 return(error); 2039 } 2040 2041 /* 2042 * This function deletes remaining auxillary records when an inode is 2043 * being deleted. This function explicitly does not delete the 2044 * inode record, directory entry, data, or db records. Those must be 2045 * properly disposed of prior to this call. 2046 */ 2047 int 2048 hammer_ip_delete_clean(hammer_cursor_t cursor, hammer_inode_t ip, int *countp) 2049 { 2050 hammer_transaction_t trans = cursor->trans; 2051 hammer_btree_leaf_elm_t leaf; 2052 int error; 2053 2054 KKASSERT(trans->type == HAMMER_TRANS_FLS); 2055 retry: 2056 hammer_normalize_cursor(cursor); 2057 cursor->key_beg.localization = ip->obj_localization + 2058 HAMMER_LOCALIZE_MISC; 2059 cursor->key_beg.obj_id = ip->obj_id; 2060 cursor->key_beg.create_tid = 0; 2061 cursor->key_beg.delete_tid = 0; 2062 cursor->key_beg.obj_type = 0; 2063 cursor->key_beg.rec_type = HAMMER_RECTYPE_CLEAN_START; 2064 cursor->key_beg.key = HAMMER_MIN_KEY; 2065 2066 cursor->key_end = cursor->key_beg; 2067 cursor->key_end.rec_type = HAMMER_RECTYPE_MAX; 2068 cursor->key_end.key = HAMMER_MAX_KEY; 2069 2070 cursor->asof = ip->obj_asof; 2071 cursor->flags &= ~HAMMER_CURSOR_INITMASK; 2072 cursor->flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF; 2073 cursor->flags |= HAMMER_CURSOR_DELETE_VISIBILITY; 2074 cursor->flags |= HAMMER_CURSOR_BACKEND; 2075 2076 error = hammer_ip_first(cursor); 2077 2078 /* 2079 * Iterate through matching records and mark them as deleted. 2080 */ 2081 while (error == 0) { 2082 leaf = cursor->leaf; 2083 2084 KKASSERT(leaf->base.delete_tid == 0); 2085 2086 /* 2087 * Mark the record and B-Tree entry as deleted. This will 2088 * also physically delete the B-Tree entry, record, and 2089 * data if the retention policy dictates. The function 2090 * will set HAMMER_CURSOR_RETEST to cause hammer_ip_next() 2091 * to retest the new 'current' element. 2092 * 2093 * Directory entries (and delete-on-disk directory entries) 2094 * must be synced and cannot be deleted. 2095 */ 2096 error = hammer_ip_delete_record(cursor, ip, trans->tid); 2097 ++*countp; 2098 if (error) 2099 break; 2100 error = hammer_ip_next(cursor); 2101 } 2102 if (cursor->node) 2103 hammer_cache_node(&ip->cache[1], cursor->node); 2104 if (error == EDEADLK) { 2105 hammer_done_cursor(cursor); 2106 error = hammer_init_cursor(trans, cursor, &ip->cache[1], ip); 2107 if (error == 0) 2108 goto retry; 2109 } 2110 if (error == ENOENT) 2111 error = 0; 2112 return(error); 2113 } 2114 2115 /* 2116 * Delete the record at the current cursor. On success the cursor will 2117 * be positioned appropriately for an iteration but may no longer be at 2118 * a leaf node. 2119 * 2120 * This routine is only called from the backend. 2121 * 2122 * NOTE: This can return EDEADLK, requiring the caller to terminate the 2123 * cursor and retry. 2124 */ 2125 int 2126 hammer_ip_delete_record(hammer_cursor_t cursor, hammer_inode_t ip, 2127 hammer_tid_t tid) 2128 { 2129 hammer_record_t iprec; 2130 hammer_mount_t hmp; 2131 int error; 2132 2133 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND); 2134 KKASSERT(tid != 0); 2135 hmp = cursor->node->hmp; 2136 2137 /* 2138 * In-memory (unsynchronized) records can simply be freed. This 2139 * only occurs in range iterations since all other records are 2140 * individually synchronized. Thus there should be no confusion with 2141 * the interlock. 2142 * 2143 * An in-memory record may be deleted before being committed to disk, 2144 * but could have been accessed in the mean time. The reservation 2145 * code will deal with the case. 2146 */ 2147 if (hammer_cursor_inmem(cursor)) { 2148 iprec = cursor->iprec; 2149 KKASSERT((iprec->flags & HAMMER_RECF_INTERLOCK_BE) ==0); 2150 iprec->flags |= HAMMER_RECF_DELETED_FE; 2151 iprec->flags |= HAMMER_RECF_DELETED_BE; 2152 KKASSERT(iprec->ip == ip); 2153 ++ip->rec_generation; 2154 return(0); 2155 } 2156 2157 /* 2158 * On-disk records are marked as deleted by updating their delete_tid. 2159 * This does not effect their position in the B-Tree (which is based 2160 * on their create_tid). 2161 * 2162 * Frontend B-Tree operations track inodes so we tell 2163 * hammer_delete_at_cursor() not to. 2164 */ 2165 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_LEAF); 2166 2167 if (error == 0) { 2168 error = hammer_delete_at_cursor( 2169 cursor, 2170 HAMMER_DELETE_ADJUST | hammer_nohistory(ip), 2171 cursor->trans->tid, 2172 cursor->trans->time32, 2173 0, NULL); 2174 } 2175 return(error); 2176 } 2177 2178 /* 2179 * Delete the B-Tree element at the current cursor and do any necessary 2180 * mirror propagation. 2181 * 2182 * The cursor must be properly positioned for an iteration on return but 2183 * may be pointing at an internal element. 2184 * 2185 * An element can be un-deleted by passing a delete_tid of 0 with 2186 * HAMMER_DELETE_ADJUST. 2187 */ 2188 int 2189 hammer_delete_at_cursor(hammer_cursor_t cursor, int delete_flags, 2190 hammer_tid_t delete_tid, u_int32_t delete_ts, 2191 int track, int64_t *stat_bytes) 2192 { 2193 struct hammer_btree_leaf_elm save_leaf; 2194 hammer_transaction_t trans; 2195 hammer_btree_leaf_elm_t leaf; 2196 hammer_node_t node; 2197 hammer_btree_elm_t elm; 2198 hammer_off_t data_offset; 2199 int32_t data_len; 2200 u_int16_t rec_type; 2201 int error; 2202 int icount; 2203 int doprop; 2204 2205 error = hammer_cursor_upgrade(cursor); 2206 if (error) 2207 return(error); 2208 2209 trans = cursor->trans; 2210 node = cursor->node; 2211 elm = &node->ondisk->elms[cursor->index]; 2212 leaf = &elm->leaf; 2213 KKASSERT(elm->base.btype == HAMMER_BTREE_TYPE_RECORD); 2214 2215 hammer_sync_lock_sh(trans); 2216 doprop = 0; 2217 icount = 0; 2218 2219 /* 2220 * Adjust the delete_tid. Update the mirror_tid propagation field 2221 * as well. delete_tid can be 0 (undelete -- used by mirroring). 2222 */ 2223 if (delete_flags & HAMMER_DELETE_ADJUST) { 2224 if (elm->base.rec_type == HAMMER_RECTYPE_INODE) { 2225 if (elm->leaf.base.delete_tid == 0 && delete_tid) 2226 icount = -1; 2227 if (elm->leaf.base.delete_tid && delete_tid == 0) 2228 icount = 1; 2229 } 2230 2231 hammer_modify_node(trans, node, elm, sizeof(*elm)); 2232 elm->leaf.base.delete_tid = delete_tid; 2233 elm->leaf.delete_ts = delete_ts; 2234 hammer_modify_node_done(node); 2235 2236 if (elm->leaf.base.delete_tid > node->ondisk->mirror_tid) { 2237 hammer_modify_node_field(trans, node, mirror_tid); 2238 node->ondisk->mirror_tid = elm->leaf.base.delete_tid; 2239 hammer_modify_node_done(node); 2240 doprop = 1; 2241 if (hammer_debug_general & 0x0002) { 2242 kprintf("delete_at_cursor: propagate %016llx" 2243 " @%016llx\n", 2244 elm->leaf.base.delete_tid, 2245 node->node_offset); 2246 } 2247 } 2248 2249 /* 2250 * Adjust for the iteration. We have deleted the current 2251 * element and want to clear ATEDISK so the iteration does 2252 * not skip the element after, which now becomes the current 2253 * element. This element must be re-tested if doing an 2254 * iteration, which is handled by the RETEST flag. 2255 */ 2256 if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) { 2257 cursor->flags |= HAMMER_CURSOR_RETEST; 2258 cursor->flags &= ~HAMMER_CURSOR_ATEDISK; 2259 } 2260 2261 /* 2262 * An on-disk record cannot have the same delete_tid 2263 * as its create_tid. In a chain of record updates 2264 * this could result in a duplicate record. 2265 */ 2266 KKASSERT(elm->leaf.base.delete_tid != 2267 elm->leaf.base.create_tid); 2268 } 2269 2270 /* 2271 * Destroy the B-Tree element if asked (typically if a nohistory 2272 * file or mount, or when called by the pruning code). 2273 * 2274 * Adjust the ATEDISK flag to properly support iterations. 2275 */ 2276 if (delete_flags & HAMMER_DELETE_DESTROY) { 2277 data_offset = elm->leaf.data_offset; 2278 data_len = elm->leaf.data_len; 2279 rec_type = elm->leaf.base.rec_type; 2280 if (doprop) { 2281 save_leaf = elm->leaf; 2282 leaf = &save_leaf; 2283 } 2284 if (elm->base.rec_type == HAMMER_RECTYPE_INODE && 2285 elm->leaf.base.delete_tid == 0) { 2286 icount = -1; 2287 } 2288 2289 error = hammer_btree_delete(cursor); 2290 if (error == 0) { 2291 /* 2292 * The deletion moves the next element (if any) to 2293 * the current element position. We must clear 2294 * ATEDISK so this element is not skipped and we 2295 * must set RETEST to force any iteration to re-test 2296 * the element. 2297 */ 2298 if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) { 2299 cursor->flags |= HAMMER_CURSOR_RETEST; 2300 cursor->flags &= ~HAMMER_CURSOR_ATEDISK; 2301 } 2302 } 2303 if (error == 0) { 2304 switch(data_offset & HAMMER_OFF_ZONE_MASK) { 2305 case HAMMER_ZONE_LARGE_DATA: 2306 case HAMMER_ZONE_SMALL_DATA: 2307 case HAMMER_ZONE_META: 2308 hammer_blockmap_free(trans, 2309 data_offset, data_len); 2310 break; 2311 default: 2312 break; 2313 } 2314 } 2315 } 2316 2317 /* 2318 * Track inode count and next_tid. This is used by the mirroring 2319 * and PFS code. icount can be negative, zero, or positive. 2320 */ 2321 if (error == 0 && track) { 2322 if (icount) { 2323 hammer_modify_volume_field(trans, trans->rootvol, 2324 vol0_stat_inodes); 2325 trans->rootvol->ondisk->vol0_stat_inodes += icount; 2326 hammer_modify_volume_done(trans->rootvol); 2327 } 2328 if (trans->rootvol->ondisk->vol0_next_tid < delete_tid) { 2329 hammer_modify_volume(trans, trans->rootvol, NULL, 0); 2330 trans->rootvol->ondisk->vol0_next_tid = delete_tid; 2331 hammer_modify_volume_done(trans->rootvol); 2332 } 2333 } 2334 2335 /* 2336 * mirror_tid propagation occurs if the node's mirror_tid had to be 2337 * updated while adjusting the delete_tid. 2338 * 2339 * This occurs when deleting even in nohistory mode, but does not 2340 * occur when pruning an already-deleted node. 2341 * 2342 * cursor->ip is NULL when called from the pruning, mirroring, 2343 * and pfs code. If non-NULL propagation will be conditionalized 2344 * on whether the PFS is in no-history mode or not. 2345 */ 2346 if (doprop) { 2347 if (cursor->ip) 2348 hammer_btree_do_propagation(cursor, cursor->ip->pfsm, leaf); 2349 else 2350 hammer_btree_do_propagation(cursor, NULL, leaf); 2351 } 2352 hammer_sync_unlock(trans); 2353 return (error); 2354 } 2355 2356 /* 2357 * Determine whether we can remove a directory. This routine checks whether 2358 * a directory is empty or not and enforces flush connectivity. 2359 * 2360 * Flush connectivity requires that we block if the target directory is 2361 * currently flushing, otherwise it may not end up in the same flush group. 2362 * 2363 * Returns 0 on success, ENOTEMPTY or EDEADLK (or other errors) on failure. 2364 */ 2365 int 2366 hammer_ip_check_directory_empty(hammer_transaction_t trans, hammer_inode_t ip) 2367 { 2368 struct hammer_cursor cursor; 2369 int error; 2370 2371 /* 2372 * Check directory empty 2373 */ 2374 hammer_init_cursor(trans, &cursor, &ip->cache[1], ip); 2375 2376 cursor.key_beg.localization = ip->obj_localization + 2377 HAMMER_LOCALIZE_MISC; 2378 cursor.key_beg.obj_id = ip->obj_id; 2379 cursor.key_beg.create_tid = 0; 2380 cursor.key_beg.delete_tid = 0; 2381 cursor.key_beg.obj_type = 0; 2382 cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE + 1; 2383 cursor.key_beg.key = HAMMER_MIN_KEY; 2384 2385 cursor.key_end = cursor.key_beg; 2386 cursor.key_end.rec_type = 0xFFFF; 2387 cursor.key_end.key = HAMMER_MAX_KEY; 2388 2389 cursor.asof = ip->obj_asof; 2390 cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF; 2391 2392 error = hammer_ip_first(&cursor); 2393 if (error == ENOENT) 2394 error = 0; 2395 else if (error == 0) 2396 error = ENOTEMPTY; 2397 hammer_done_cursor(&cursor); 2398 return(error); 2399 } 2400 2401