1 /* 2 * Copyright (c) 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_reblock.c,v 1.34 2008/11/13 02:18:43 dillon Exp $ 35 */ 36 /* 37 * HAMMER reblocker - This code frees up fragmented physical space 38 * 39 * HAMMER only keeps track of free space on a big-block basis. A big-block 40 * containing holes can only be freed by migrating the remaining data in 41 * that big-block into a new big-block, then freeing the big-block. 42 * 43 * This function is called from an ioctl or via the hammer support thread. 44 */ 45 46 #include "hammer.h" 47 48 static int hammer_reblock_helper(struct hammer_ioc_reblock *reblock, 49 hammer_cursor_t cursor, 50 hammer_btree_elm_t elm); 51 static int hammer_reblock_data(struct hammer_ioc_reblock *reblock, 52 hammer_cursor_t cursor, hammer_btree_elm_t elm); 53 static int hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock, 54 hammer_cursor_t cursor, hammer_btree_elm_t elm); 55 static int hammer_reblock_int_node(struct hammer_ioc_reblock *reblock, 56 hammer_cursor_t cursor, hammer_btree_elm_t elm); 57 58 int 59 hammer_ioc_reblock(hammer_transaction_t trans, hammer_inode_t ip, 60 struct hammer_ioc_reblock *reblock) 61 { 62 struct hammer_cursor cursor; 63 hammer_btree_elm_t elm; 64 int checkspace_count; 65 int error; 66 int seq; 67 int slop; 68 69 /* 70 * A fill level <= 20% is considered an emergency. free_level is 71 * inverted from fill_level. 72 */ 73 if (reblock->free_level >= HAMMER_LARGEBLOCK_SIZE * 8 / 10) 74 slop = HAMMER_CHKSPC_EMERGENCY; 75 else 76 slop = HAMMER_CHKSPC_REBLOCK; 77 78 if ((reblock->key_beg.localization | reblock->key_end.localization) & 79 HAMMER_LOCALIZE_PSEUDOFS_MASK) { 80 return(EINVAL); 81 } 82 if (reblock->key_beg.obj_id >= reblock->key_end.obj_id) 83 return(EINVAL); 84 if (reblock->free_level < 0) 85 return(EINVAL); 86 87 reblock->key_cur = reblock->key_beg; 88 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK; 89 reblock->key_cur.localization += ip->obj_localization; 90 91 checkspace_count = 0; 92 seq = trans->hmp->flusher.done; 93 retry: 94 error = hammer_init_cursor(trans, &cursor, NULL, NULL); 95 if (error) { 96 hammer_done_cursor(&cursor); 97 goto failed; 98 } 99 cursor.key_beg.localization = reblock->key_cur.localization; 100 cursor.key_beg.obj_id = reblock->key_cur.obj_id; 101 cursor.key_beg.key = HAMMER_MIN_KEY; 102 cursor.key_beg.create_tid = 1; 103 cursor.key_beg.delete_tid = 0; 104 cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE; 105 cursor.key_beg.obj_type = 0; 106 107 cursor.key_end.localization = (reblock->key_end.localization & 108 HAMMER_LOCALIZE_MASK) + 109 ip->obj_localization; 110 cursor.key_end.obj_id = reblock->key_end.obj_id; 111 cursor.key_end.key = HAMMER_MAX_KEY; 112 cursor.key_end.create_tid = HAMMER_MAX_TID - 1; 113 cursor.key_end.delete_tid = 0; 114 cursor.key_end.rec_type = HAMMER_MAX_RECTYPE; 115 cursor.key_end.obj_type = 0; 116 117 cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE; 118 cursor.flags |= HAMMER_CURSOR_BACKEND; 119 cursor.flags |= HAMMER_CURSOR_NOSWAPCACHE; 120 121 /* 122 * This flag allows the btree scan code to return internal nodes, 123 * so we can reblock them in addition to the leafs. Only specify it 124 * if we intend to reblock B-Tree nodes. 125 */ 126 if (reblock->head.flags & HAMMER_IOC_DO_BTREE) 127 cursor.flags |= HAMMER_CURSOR_REBLOCKING; 128 129 error = hammer_btree_first(&cursor); 130 while (error == 0) { 131 /* 132 * Internal or Leaf node 133 */ 134 KKASSERT(cursor.index < cursor.node->ondisk->count); 135 elm = &cursor.node->ondisk->elms[cursor.index]; 136 reblock->key_cur.obj_id = elm->base.obj_id; 137 reblock->key_cur.localization = elm->base.localization; 138 139 /* 140 * Yield to more important tasks 141 */ 142 if ((error = hammer_signal_check(trans->hmp)) != 0) 143 break; 144 145 /* 146 * If there is insufficient free space it may be due to 147 * reserved bigblocks, which flushing might fix. 148 * 149 * We must force a retest in case the unlocked cursor is 150 * moved to the end of the leaf, or moved to an internal 151 * node. 152 * 153 * WARNING: See warnings in hammer_unlock_cursor() function. 154 */ 155 if (hammer_checkspace(trans->hmp, slop)) { 156 if (++checkspace_count == 10) { 157 error = ENOSPC; 158 break; 159 } 160 hammer_unlock_cursor(&cursor); 161 cursor.flags |= HAMMER_CURSOR_RETEST; 162 hammer_flusher_wait(trans->hmp, seq); 163 hammer_lock_cursor(&cursor); 164 seq = hammer_flusher_async(trans->hmp, NULL); 165 goto skip; 166 } 167 168 /* 169 * Acquiring the sync_lock prevents the operation from 170 * crossing a synchronization boundary. 171 * 172 * NOTE: cursor.node may have changed on return. 173 * 174 * WARNING: See warnings in hammer_unlock_cursor() function. 175 */ 176 hammer_sync_lock_sh(trans); 177 error = hammer_reblock_helper(reblock, &cursor, elm); 178 hammer_sync_unlock(trans); 179 180 while (hammer_flusher_meta_halflimit(trans->hmp) || 181 hammer_flusher_undo_exhausted(trans, 2)) { 182 hammer_unlock_cursor(&cursor); 183 hammer_flusher_wait(trans->hmp, seq); 184 hammer_lock_cursor(&cursor); 185 seq = hammer_flusher_async_one(trans->hmp); 186 } 187 188 /* 189 * Setup for iteration, our cursor flags may be modified by 190 * other threads while we are unlocked. 191 */ 192 cursor.flags |= HAMMER_CURSOR_ATEDISK; 193 194 /* 195 * We allocate data buffers, which atm we don't track 196 * dirty levels for because we allow the kernel to write 197 * them. But if we allocate too many we can still deadlock 198 * the buffer cache. 199 * 200 * WARNING: See warnings in hammer_unlock_cursor() function. 201 * (The cursor's node and element may change!) 202 */ 203 if (bd_heatup()) { 204 hammer_unlock_cursor(&cursor); 205 bwillwrite(HAMMER_XBUFSIZE); 206 hammer_lock_cursor(&cursor); 207 } 208 skip: 209 if (error == 0) { 210 error = hammer_btree_iterate(&cursor); 211 } 212 } 213 if (error == ENOENT) 214 error = 0; 215 hammer_done_cursor(&cursor); 216 if (error == EWOULDBLOCK) { 217 hammer_flusher_sync(trans->hmp); 218 goto retry; 219 } 220 if (error == EDEADLK) 221 goto retry; 222 if (error == EINTR) { 223 reblock->head.flags |= HAMMER_IOC_HEAD_INTR; 224 error = 0; 225 } 226 failed: 227 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK; 228 return(error); 229 } 230 231 /* 232 * Reblock the B-Tree (leaf) node, record, and/or data if necessary. 233 * 234 * XXX We have no visibility into internal B-Tree nodes at the moment, 235 * only leaf nodes. 236 */ 237 static int 238 hammer_reblock_helper(struct hammer_ioc_reblock *reblock, 239 hammer_cursor_t cursor, hammer_btree_elm_t elm) 240 { 241 hammer_mount_t hmp; 242 hammer_off_t tmp_offset; 243 hammer_node_ondisk_t ondisk; 244 struct hammer_btree_leaf_elm leaf; 245 int error; 246 int bytes; 247 int cur; 248 int iocflags; 249 250 error = 0; 251 hmp = cursor->trans->hmp; 252 253 /* 254 * Reblock data. Note that data embedded in a record is reblocked 255 * by the record reblock code. Data processing only occurs at leaf 256 * nodes and for RECORD element types. 257 */ 258 if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF) 259 goto skip; 260 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD) 261 return(0); 262 tmp_offset = elm->leaf.data_offset; 263 if (tmp_offset == 0) 264 goto skip; 265 if (error) 266 goto skip; 267 268 /* 269 * NOTE: Localization restrictions may also have been set-up, we can't 270 * just set the match flags willy-nilly here. 271 */ 272 switch(elm->leaf.base.rec_type) { 273 case HAMMER_RECTYPE_INODE: 274 case HAMMER_RECTYPE_SNAPSHOT: 275 case HAMMER_RECTYPE_CONFIG: 276 iocflags = HAMMER_IOC_DO_INODES; 277 break; 278 case HAMMER_RECTYPE_EXT: 279 case HAMMER_RECTYPE_FIX: 280 case HAMMER_RECTYPE_PFS: 281 case HAMMER_RECTYPE_DIRENTRY: 282 iocflags = HAMMER_IOC_DO_DIRS; 283 break; 284 case HAMMER_RECTYPE_DATA: 285 case HAMMER_RECTYPE_DB: 286 iocflags = HAMMER_IOC_DO_DATA; 287 break; 288 default: 289 iocflags = 0; 290 break; 291 } 292 if (reblock->head.flags & iocflags) { 293 ++reblock->data_count; 294 reblock->data_byte_count += elm->leaf.data_len; 295 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error); 296 if (hammer_debug_general & 0x4000) 297 kprintf("D %6d/%d\n", bytes, reblock->free_level); 298 if (error == 0 && (cur == 0 || reblock->free_level == 0) && 299 bytes >= reblock->free_level) { 300 /* 301 * This is nasty, the uncache code may have to get 302 * vnode locks and because of that we can't hold 303 * the cursor locked. 304 * 305 * WARNING: See warnings in hammer_unlock_cursor() 306 * function. 307 */ 308 leaf = elm->leaf; 309 hammer_unlock_cursor(cursor); 310 hammer_io_direct_uncache(hmp, &leaf); 311 hammer_lock_cursor(cursor); 312 313 /* 314 * elm may have become stale or invalid, reload it. 315 * ondisk variable is temporary only. Note that 316 * cursor->node and thus cursor->node->ondisk may 317 * also changed. 318 */ 319 ondisk = cursor->node->ondisk; 320 elm = &ondisk->elms[cursor->index]; 321 if (cursor->flags & HAMMER_CURSOR_RETEST) { 322 kprintf("hammer: debug: retest on " 323 "reblocker uncache\n"); 324 error = EDEADLK; 325 } else if (ondisk->type != HAMMER_BTREE_TYPE_LEAF || 326 cursor->index >= ondisk->count) { 327 kprintf("hammer: debug: shifted on " 328 "reblocker uncache\n"); 329 error = EDEADLK; 330 } else if (bcmp(&elm->leaf, &leaf, sizeof(leaf))) { 331 kprintf("hammer: debug: changed on " 332 "reblocker uncache\n"); 333 error = EDEADLK; 334 } 335 if (error == 0) 336 error = hammer_cursor_upgrade(cursor); 337 if (error == 0) { 338 KKASSERT(cursor->index < ondisk->count); 339 error = hammer_reblock_data(reblock, 340 cursor, elm); 341 } 342 if (error == 0) { 343 ++reblock->data_moves; 344 reblock->data_byte_moves += elm->leaf.data_len; 345 } 346 } 347 } 348 349 skip: 350 /* 351 * Reblock a B-Tree internal or leaf node. A leaf node is reblocked 352 * on initial entry only (element 0). An internal node is reblocked 353 * when entered upward from its first leaf node only (also element 0). 354 * Further revisits of the internal node (index > 0) are ignored. 355 */ 356 tmp_offset = cursor->node->node_offset; 357 if (cursor->index == 0 && 358 error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) { 359 ++reblock->btree_count; 360 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error); 361 if (hammer_debug_general & 0x4000) 362 kprintf("B %6d/%d\n", bytes, reblock->free_level); 363 if (error == 0 && (cur == 0 || reblock->free_level == 0) && 364 bytes >= reblock->free_level) { 365 error = hammer_cursor_upgrade(cursor); 366 if (error == 0) { 367 if (cursor->parent) { 368 KKASSERT(cursor->parent_index < 369 cursor->parent->ondisk->count); 370 elm = &cursor->parent->ondisk->elms[cursor->parent_index]; 371 } else { 372 elm = NULL; 373 } 374 switch(cursor->node->ondisk->type) { 375 case HAMMER_BTREE_TYPE_LEAF: 376 error = hammer_reblock_leaf_node( 377 reblock, cursor, elm); 378 break; 379 case HAMMER_BTREE_TYPE_INTERNAL: 380 error = hammer_reblock_int_node( 381 reblock, cursor, elm); 382 break; 383 default: 384 panic("Illegal B-Tree node type"); 385 } 386 } 387 if (error == 0) { 388 ++reblock->btree_moves; 389 } 390 } 391 } 392 393 hammer_cursor_downgrade(cursor); 394 return(error); 395 } 396 397 /* 398 * Reblock a record's data. Both the B-Tree element and record pointers 399 * to the data must be adjusted. 400 */ 401 static int 402 hammer_reblock_data(struct hammer_ioc_reblock *reblock, 403 hammer_cursor_t cursor, hammer_btree_elm_t elm) 404 { 405 struct hammer_buffer *data_buffer = NULL; 406 hammer_off_t ndata_offset; 407 int error; 408 void *ndata; 409 410 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA | 411 HAMMER_CURSOR_GET_LEAF); 412 if (error) 413 return (error); 414 ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len, 415 elm->leaf.base.rec_type, 416 &ndata_offset, &data_buffer, 417 0, &error); 418 if (error) 419 goto done; 420 hammer_io_notmeta(data_buffer); 421 422 /* 423 * Move the data. Note that we must invalidate any cached 424 * data buffer in the cursor before calling blockmap_free. 425 * The blockmap_free may free up the entire large-block and 426 * will not be able to invalidate it if the cursor is holding 427 * a data buffer cached in that large block. 428 */ 429 hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0); 430 bcopy(cursor->data, ndata, elm->leaf.data_len); 431 hammer_modify_buffer_done(data_buffer); 432 hammer_cursor_invalidate_cache(cursor); 433 434 hammer_blockmap_free(cursor->trans, 435 elm->leaf.data_offset, elm->leaf.data_len); 436 437 hammer_modify_node(cursor->trans, cursor->node, 438 &elm->leaf.data_offset, sizeof(hammer_off_t)); 439 elm->leaf.data_offset = ndata_offset; 440 hammer_modify_node_done(cursor->node); 441 442 done: 443 if (data_buffer) 444 hammer_rel_buffer(data_buffer, 0); 445 return (error); 446 } 447 448 /* 449 * Reblock a B-Tree leaf node. The parent must be adjusted to point to 450 * the new copy of the leaf node. 451 * 452 * elm is a pointer to the parent element pointing at cursor.node. 453 */ 454 static int 455 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock, 456 hammer_cursor_t cursor, hammer_btree_elm_t elm) 457 { 458 hammer_node_t onode; 459 hammer_node_t nnode; 460 int error; 461 462 /* 463 * Don't supply a hint when allocating the leaf. Fills are done 464 * from the leaf upwards. 465 */ 466 onode = cursor->node; 467 nnode = hammer_alloc_btree(cursor->trans, 0, &error); 468 469 if (nnode == NULL) 470 return (error); 471 472 /* 473 * Move the node 474 */ 475 hammer_lock_ex(&nnode->lock); 476 hammer_modify_node_noundo(cursor->trans, nnode); 477 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk)); 478 479 if (elm) { 480 /* 481 * We are not the root of the B-Tree 482 */ 483 hammer_modify_node(cursor->trans, cursor->parent, 484 &elm->internal.subtree_offset, 485 sizeof(elm->internal.subtree_offset)); 486 elm->internal.subtree_offset = nnode->node_offset; 487 hammer_modify_node_done(cursor->parent); 488 } else { 489 /* 490 * We are the root of the B-Tree 491 */ 492 hammer_volume_t volume; 493 494 volume = hammer_get_root_volume(cursor->trans->hmp, &error); 495 KKASSERT(error == 0); 496 497 hammer_modify_volume_field(cursor->trans, volume, 498 vol0_btree_root); 499 volume->ondisk->vol0_btree_root = nnode->node_offset; 500 hammer_modify_volume_done(volume); 501 hammer_rel_volume(volume, 0); 502 } 503 504 hammer_cursor_replaced_node(onode, nnode); 505 hammer_delete_node(cursor->trans, onode); 506 507 if (hammer_debug_general & 0x4000) { 508 kprintf("REBLOCK LNODE %016llx -> %016llx\n", 509 (long long)onode->node_offset, 510 (long long)nnode->node_offset); 511 } 512 hammer_modify_node_done(nnode); 513 cursor->node = nnode; 514 515 hammer_unlock(&onode->lock); 516 hammer_rel_node(onode); 517 518 return (error); 519 } 520 521 /* 522 * Reblock a B-Tree internal node. The parent must be adjusted to point to 523 * the new copy of the internal node, and the node's children's parent 524 * pointers must also be adjusted to point to the new copy. 525 * 526 * elm is a pointer to the parent element pointing at cursor.node. 527 */ 528 static int 529 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock, 530 hammer_cursor_t cursor, hammer_btree_elm_t elm) 531 { 532 struct hammer_node_lock lockroot; 533 hammer_node_t onode; 534 hammer_node_t nnode; 535 hammer_off_t hint; 536 int error; 537 int i; 538 539 hammer_node_lock_init(&lockroot, cursor->node); 540 error = hammer_btree_lock_children(cursor, 1, &lockroot, NULL); 541 if (error) 542 goto done; 543 544 /* 545 * The internal node is visited after recursing through its 546 * first element. Use the subtree offset allocated for that 547 * element as a hint for allocating the internal node. 548 */ 549 onode = cursor->node; 550 if (onode->ondisk->count) 551 hint = onode->ondisk->elms[0].internal.subtree_offset; 552 else 553 hint = 0; 554 nnode = hammer_alloc_btree(cursor->trans, 0, &error); 555 556 if (nnode == NULL) 557 goto done; 558 559 /* 560 * Move the node. Adjust the parent's pointer to us first. 561 */ 562 hammer_lock_ex(&nnode->lock); 563 hammer_modify_node_noundo(cursor->trans, nnode); 564 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk)); 565 566 if (elm) { 567 /* 568 * We are not the root of the B-Tree 569 */ 570 hammer_modify_node(cursor->trans, cursor->parent, 571 &elm->internal.subtree_offset, 572 sizeof(elm->internal.subtree_offset)); 573 elm->internal.subtree_offset = nnode->node_offset; 574 hammer_modify_node_done(cursor->parent); 575 } else { 576 /* 577 * We are the root of the B-Tree 578 */ 579 hammer_volume_t volume; 580 581 volume = hammer_get_root_volume(cursor->trans->hmp, &error); 582 KKASSERT(error == 0); 583 584 hammer_modify_volume_field(cursor->trans, volume, 585 vol0_btree_root); 586 volume->ondisk->vol0_btree_root = nnode->node_offset; 587 hammer_modify_volume_done(volume); 588 hammer_rel_volume(volume, 0); 589 } 590 591 /* 592 * Now adjust our children's pointers to us. 593 */ 594 for (i = 0; i < nnode->ondisk->count; ++i) { 595 elm = &nnode->ondisk->elms[i]; 596 error = btree_set_parent(cursor->trans, nnode, elm); 597 if (error) 598 panic("reblock internal node: fixup problem"); 599 } 600 601 /* 602 * Clean up. 603 * 604 * The new node replaces the current node in the cursor. The cursor 605 * expects it to be locked so leave it locked. Discard onode. 606 */ 607 hammer_cursor_replaced_node(onode, nnode); 608 hammer_delete_node(cursor->trans, onode); 609 610 if (hammer_debug_general & 0x4000) { 611 kprintf("REBLOCK INODE %016llx -> %016llx\n", 612 (long long)onode->node_offset, 613 (long long)nnode->node_offset); 614 } 615 hammer_modify_node_done(nnode); 616 cursor->node = nnode; 617 618 hammer_unlock(&onode->lock); 619 hammer_rel_node(onode); 620 621 done: 622 hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL); 623 return (error); 624 } 625 626