1 /* 2 * Copyright (c) 2008-2012 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 /* 35 * HAMMER reblocker - This code frees up fragmented physical space 36 * 37 * HAMMER only keeps track of free space on a big-block basis. A big-block 38 * containing holes can only be freed by migrating the remaining data in 39 * that big-block into a new big-block, then freeing the big-block. 40 * 41 * This function is called from an ioctl or via the hammer support thread. 42 */ 43 44 #include "hammer.h" 45 46 static int hammer_reblock_helper(struct hammer_ioc_reblock *reblock, 47 hammer_cursor_t cursor, 48 hammer_btree_elm_t elm); 49 static int hammer_reblock_data(struct hammer_ioc_reblock *reblock, 50 hammer_cursor_t cursor, hammer_btree_elm_t elm); 51 static int hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock, 52 hammer_cursor_t cursor, hammer_btree_elm_t elm); 53 static int hammer_reblock_int_node(struct hammer_ioc_reblock *reblock, 54 hammer_cursor_t cursor, hammer_btree_elm_t elm); 55 56 int 57 hammer_ioc_reblock(hammer_transaction_t trans, hammer_inode_t ip, 58 struct hammer_ioc_reblock *reblock) 59 { 60 struct hammer_cursor cursor; 61 hammer_btree_elm_t elm; 62 int checkspace_count; 63 int error; 64 int seq; 65 int slop; 66 u_int32_t key_end_localization; 67 68 if ((reblock->key_beg.localization | reblock->key_end.localization) & 69 HAMMER_LOCALIZE_PSEUDOFS_MASK) { 70 return(EINVAL); 71 } 72 if (reblock->key_beg.obj_id >= reblock->key_end.obj_id) 73 return(EINVAL); 74 if (reblock->free_level < 0 || 75 reblock->free_level > HAMMER_BIGBLOCK_SIZE) 76 return(EINVAL); 77 78 /* 79 * A fill_percentage <= 20% is considered an emergency. free_level is 80 * inverted from fill_percentage. 81 */ 82 if (reblock->free_level >= HAMMER_BIGBLOCK_SIZE * 8 / 10) 83 slop = HAMMER_CHKSPC_EMERGENCY; 84 else 85 slop = HAMMER_CHKSPC_REBLOCK; 86 87 /* 88 * Ioctl caller has only set localization type to reblock. 89 * Initialize cursor key localization with ip localization. 90 */ 91 reblock->key_cur = reblock->key_beg; 92 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK; 93 reblock->key_cur.localization += ip->obj_localization; 94 95 key_end_localization = reblock->key_end.localization; 96 key_end_localization &= HAMMER_LOCALIZE_MASK; 97 key_end_localization += ip->obj_localization; 98 99 checkspace_count = 0; 100 seq = trans->hmp->flusher.done; 101 retry: 102 error = hammer_init_cursor(trans, &cursor, NULL, NULL); 103 if (error) { 104 hammer_done_cursor(&cursor); 105 goto failed; 106 } 107 cursor.key_beg.localization = reblock->key_cur.localization; 108 cursor.key_beg.obj_id = reblock->key_cur.obj_id; 109 cursor.key_beg.key = HAMMER_MIN_KEY; 110 cursor.key_beg.create_tid = 1; 111 cursor.key_beg.delete_tid = 0; 112 cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE; 113 cursor.key_beg.obj_type = 0; 114 115 cursor.key_end.localization = key_end_localization; 116 cursor.key_end.obj_id = reblock->key_end.obj_id; 117 cursor.key_end.key = HAMMER_MAX_KEY; 118 cursor.key_end.create_tid = HAMMER_MAX_TID - 1; 119 cursor.key_end.delete_tid = 0; 120 cursor.key_end.rec_type = HAMMER_MAX_RECTYPE; 121 cursor.key_end.obj_type = 0; 122 123 cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE; 124 cursor.flags |= HAMMER_CURSOR_BACKEND; 125 cursor.flags |= HAMMER_CURSOR_NOSWAPCACHE; 126 127 /* 128 * This flag allows the btree scan code to return internal nodes, 129 * so we can reblock them in addition to the leafs. Only specify it 130 * if we intend to reblock B-Tree nodes. 131 */ 132 if (reblock->head.flags & HAMMER_IOC_DO_BTREE) 133 cursor.flags |= HAMMER_CURSOR_REBLOCKING; 134 135 error = hammer_btree_first(&cursor); 136 while (error == 0) { 137 /* 138 * Internal or Leaf node 139 */ 140 KKASSERT(cursor.index < cursor.node->ondisk->count); 141 elm = &cursor.node->ondisk->elms[cursor.index]; 142 reblock->key_cur.obj_id = elm->base.obj_id; 143 reblock->key_cur.localization = elm->base.localization; 144 145 /* 146 * Yield to more important tasks 147 */ 148 if ((error = hammer_signal_check(trans->hmp)) != 0) 149 break; 150 151 /* 152 * If there is insufficient free space it may be due to 153 * reserved bigblocks, which flushing might fix. 154 * 155 * We must force a retest in case the unlocked cursor is 156 * moved to the end of the leaf, or moved to an internal 157 * node. 158 * 159 * WARNING: See warnings in hammer_unlock_cursor() function. 160 */ 161 if (hammer_checkspace(trans->hmp, slop)) { 162 if (++checkspace_count == 10) { 163 error = ENOSPC; 164 break; 165 } 166 hammer_unlock_cursor(&cursor); 167 cursor.flags |= HAMMER_CURSOR_RETEST; 168 hammer_flusher_wait(trans->hmp, seq); 169 hammer_lock_cursor(&cursor); 170 seq = hammer_flusher_async(trans->hmp, NULL); 171 goto skip; 172 } 173 174 /* 175 * Acquiring the sync_lock prevents the operation from 176 * crossing a synchronization boundary. 177 * 178 * NOTE: cursor.node may have changed on return. 179 * 180 * WARNING: See warnings in hammer_unlock_cursor() function. 181 */ 182 hammer_sync_lock_sh(trans); 183 error = hammer_reblock_helper(reblock, &cursor, elm); 184 hammer_sync_unlock(trans); 185 186 while (hammer_flusher_meta_halflimit(trans->hmp) || 187 hammer_flusher_undo_exhausted(trans, 2)) { 188 hammer_unlock_cursor(&cursor); 189 hammer_flusher_wait(trans->hmp, seq); 190 hammer_lock_cursor(&cursor); 191 seq = hammer_flusher_async_one(trans->hmp); 192 } 193 194 /* 195 * Setup for iteration, our cursor flags may be modified by 196 * other threads while we are unlocked. 197 */ 198 cursor.flags |= HAMMER_CURSOR_ATEDISK; 199 200 /* 201 * We allocate data buffers, which atm we don't track 202 * dirty levels for because we allow the kernel to write 203 * them. But if we allocate too many we can still deadlock 204 * the buffer cache. 205 * 206 * WARNING: See warnings in hammer_unlock_cursor() function. 207 * (The cursor's node and element may change!) 208 */ 209 if (bd_heatup()) { 210 hammer_unlock_cursor(&cursor); 211 bwillwrite(HAMMER_XBUFSIZE); 212 hammer_lock_cursor(&cursor); 213 } 214 vm_wait_nominal(); 215 skip: 216 if (error == 0) { 217 error = hammer_btree_iterate(&cursor); 218 } 219 } 220 if (error == ENOENT) 221 error = 0; 222 hammer_done_cursor(&cursor); 223 if (error == EWOULDBLOCK) { 224 hammer_flusher_sync(trans->hmp); 225 goto retry; 226 } 227 if (error == EDEADLK) 228 goto retry; 229 if (error == EINTR) { 230 reblock->head.flags |= HAMMER_IOC_HEAD_INTR; 231 error = 0; 232 } 233 failed: 234 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK; 235 return(error); 236 } 237 238 /* 239 * Reblock the B-Tree (leaf) node, record, and/or data if necessary. 240 * 241 * XXX We have no visibility into internal B-Tree nodes at the moment, 242 * only leaf nodes. 243 */ 244 static int 245 hammer_reblock_helper(struct hammer_ioc_reblock *reblock, 246 hammer_cursor_t cursor, hammer_btree_elm_t elm) 247 { 248 hammer_mount_t hmp; 249 hammer_off_t tmp_offset; 250 hammer_node_ondisk_t ondisk; 251 struct hammer_btree_leaf_elm leaf; 252 int error; 253 int bytes; 254 int cur; 255 int iocflags; 256 257 error = 0; 258 hmp = cursor->trans->hmp; 259 260 /* 261 * Reblock data. Note that data embedded in a record is reblocked 262 * by the record reblock code. Data processing only occurs at leaf 263 * nodes and for RECORD element types. 264 */ 265 if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF) 266 goto skip; 267 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD) 268 return(0); 269 tmp_offset = elm->leaf.data_offset; 270 if (tmp_offset == 0) 271 goto skip; 272 if (error) 273 goto skip; 274 275 /* 276 * NOTE: Localization restrictions may also have been set-up, we can't 277 * just set the match flags willy-nilly here. 278 */ 279 switch(elm->leaf.base.rec_type) { 280 case HAMMER_RECTYPE_INODE: 281 case HAMMER_RECTYPE_SNAPSHOT: 282 case HAMMER_RECTYPE_CONFIG: 283 iocflags = HAMMER_IOC_DO_INODES; 284 break; 285 case HAMMER_RECTYPE_EXT: 286 case HAMMER_RECTYPE_FIX: 287 case HAMMER_RECTYPE_PFS: 288 case HAMMER_RECTYPE_DIRENTRY: 289 iocflags = HAMMER_IOC_DO_DIRS; 290 break; 291 case HAMMER_RECTYPE_DATA: 292 case HAMMER_RECTYPE_DB: 293 iocflags = HAMMER_IOC_DO_DATA; 294 break; 295 default: 296 iocflags = 0; 297 break; 298 } 299 if (reblock->head.flags & iocflags) { 300 ++reblock->data_count; 301 reblock->data_byte_count += elm->leaf.data_len; 302 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error); 303 if (hammer_debug_general & 0x4000) 304 kprintf("D %6d/%d\n", bytes, reblock->free_level); 305 if (error == 0 && (cur == 0 || reblock->free_level == 0) && 306 bytes >= reblock->free_level) { 307 /* 308 * This is nasty, the uncache code may have to get 309 * vnode locks and because of that we can't hold 310 * the cursor locked. 311 * 312 * WARNING: See warnings in hammer_unlock_cursor() 313 * function. 314 */ 315 leaf = elm->leaf; 316 hammer_unlock_cursor(cursor); 317 hammer_io_direct_uncache(hmp, &leaf); 318 hammer_lock_cursor(cursor); 319 320 /* 321 * elm may have become stale or invalid, reload it. 322 * ondisk variable is temporary only. Note that 323 * cursor->node and thus cursor->node->ondisk may 324 * also changed. 325 */ 326 ondisk = cursor->node->ondisk; 327 elm = &ondisk->elms[cursor->index]; 328 if (cursor->flags & HAMMER_CURSOR_RETEST) { 329 kprintf("hammer: debug: retest on " 330 "reblocker uncache\n"); 331 error = EDEADLK; 332 } else if (ondisk->type != HAMMER_BTREE_TYPE_LEAF || 333 cursor->index >= ondisk->count) { 334 kprintf("hammer: debug: shifted on " 335 "reblocker uncache\n"); 336 error = EDEADLK; 337 } else if (bcmp(&elm->leaf, &leaf, sizeof(leaf))) { 338 kprintf("hammer: debug: changed on " 339 "reblocker uncache\n"); 340 error = EDEADLK; 341 } 342 if (error == 0) 343 error = hammer_cursor_upgrade(cursor); 344 if (error == 0) { 345 KKASSERT(cursor->index < ondisk->count); 346 error = hammer_reblock_data(reblock, 347 cursor, elm); 348 } 349 if (error == 0) { 350 ++reblock->data_moves; 351 reblock->data_byte_moves += elm->leaf.data_len; 352 } 353 } 354 } 355 356 skip: 357 /* 358 * Reblock a B-Tree internal or leaf node. A leaf node is reblocked 359 * on initial entry only (element 0). An internal node is reblocked 360 * when entered upward from its first leaf node only (also element 0). 361 * Further revisits of the internal node (index > 0) are ignored. 362 */ 363 tmp_offset = cursor->node->node_offset; 364 if (cursor->index == 0 && 365 error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) { 366 ++reblock->btree_count; 367 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error); 368 if (hammer_debug_general & 0x4000) 369 kprintf("B %6d/%d\n", bytes, reblock->free_level); 370 if (error == 0 && (cur == 0 || reblock->free_level == 0) && 371 bytes >= reblock->free_level) { 372 error = hammer_cursor_upgrade(cursor); 373 if (error == 0) { 374 if (cursor->parent) { 375 KKASSERT(cursor->parent_index < 376 cursor->parent->ondisk->count); 377 elm = &cursor->parent->ondisk->elms[cursor->parent_index]; 378 } else { 379 elm = NULL; 380 } 381 switch(cursor->node->ondisk->type) { 382 case HAMMER_BTREE_TYPE_LEAF: 383 error = hammer_reblock_leaf_node( 384 reblock, cursor, elm); 385 break; 386 case HAMMER_BTREE_TYPE_INTERNAL: 387 error = hammer_reblock_int_node( 388 reblock, cursor, elm); 389 break; 390 default: 391 panic("Illegal B-Tree node type"); 392 } 393 } 394 if (error == 0) { 395 ++reblock->btree_moves; 396 } 397 } 398 } 399 400 hammer_cursor_downgrade(cursor); 401 return(error); 402 } 403 404 /* 405 * Reblock a record's data. Both the B-Tree element and record pointers 406 * to the data must be adjusted. 407 */ 408 static int 409 hammer_reblock_data(struct hammer_ioc_reblock *reblock, 410 hammer_cursor_t cursor, hammer_btree_elm_t elm) 411 { 412 struct hammer_buffer *data_buffer = NULL; 413 hammer_off_t ndata_offset; 414 int error; 415 void *ndata; 416 417 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA | 418 HAMMER_CURSOR_GET_LEAF); 419 if (error) 420 return (error); 421 ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len, 422 elm->leaf.base.rec_type, 423 &ndata_offset, &data_buffer, 424 0, &error); 425 if (error) 426 goto done; 427 hammer_io_notmeta(data_buffer); 428 429 /* 430 * Move the data. Note that we must invalidate any cached 431 * data buffer in the cursor before calling blockmap_free. 432 * The blockmap_free may free up the entire big-block and 433 * will not be able to invalidate it if the cursor is holding 434 * a data buffer cached in that big block. 435 */ 436 hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0); 437 bcopy(cursor->data, ndata, elm->leaf.data_len); 438 hammer_modify_buffer_done(data_buffer); 439 hammer_cursor_invalidate_cache(cursor); 440 441 hammer_blockmap_free(cursor->trans, 442 elm->leaf.data_offset, elm->leaf.data_len); 443 444 hammer_modify_node(cursor->trans, cursor->node, 445 &elm->leaf.data_offset, sizeof(hammer_off_t)); 446 elm->leaf.data_offset = ndata_offset; 447 hammer_modify_node_done(cursor->node); 448 449 done: 450 if (data_buffer) 451 hammer_rel_buffer(data_buffer, 0); 452 return (error); 453 } 454 455 /* 456 * Reblock a B-Tree leaf node. The parent must be adjusted to point to 457 * the new copy of the leaf node. 458 * 459 * elm is a pointer to the parent element pointing at cursor.node. 460 */ 461 static int 462 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock, 463 hammer_cursor_t cursor, hammer_btree_elm_t elm) 464 { 465 hammer_node_t onode; 466 hammer_node_t nnode; 467 int error; 468 469 /* 470 * Don't supply a hint when allocating the leaf. Fills are done 471 * from the leaf upwards. 472 */ 473 onode = cursor->node; 474 nnode = hammer_alloc_btree(cursor->trans, 0, &error); 475 476 if (nnode == NULL) 477 return (error); 478 479 /* 480 * Move the node 481 */ 482 hammer_lock_ex(&nnode->lock); 483 hammer_modify_node_noundo(cursor->trans, nnode); 484 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk)); 485 486 if (elm) { 487 /* 488 * We are not the root of the B-Tree 489 */ 490 hammer_modify_node(cursor->trans, cursor->parent, 491 &elm->internal.subtree_offset, 492 sizeof(elm->internal.subtree_offset)); 493 elm->internal.subtree_offset = nnode->node_offset; 494 hammer_modify_node_done(cursor->parent); 495 } else { 496 /* 497 * We are the root of the B-Tree 498 */ 499 hammer_volume_t volume; 500 501 volume = hammer_get_root_volume(cursor->trans->hmp, &error); 502 KKASSERT(error == 0); 503 504 hammer_modify_volume_field(cursor->trans, volume, 505 vol0_btree_root); 506 volume->ondisk->vol0_btree_root = nnode->node_offset; 507 hammer_modify_volume_done(volume); 508 hammer_rel_volume(volume, 0); 509 } 510 511 hammer_cursor_replaced_node(onode, nnode); 512 hammer_delete_node(cursor->trans, onode); 513 514 if (hammer_debug_general & 0x4000) { 515 kprintf("REBLOCK LNODE %016llx -> %016llx\n", 516 (long long)onode->node_offset, 517 (long long)nnode->node_offset); 518 } 519 hammer_modify_node_done(nnode); 520 cursor->node = nnode; 521 522 hammer_unlock(&onode->lock); 523 hammer_rel_node(onode); 524 525 return (error); 526 } 527 528 /* 529 * Reblock a B-Tree internal node. The parent must be adjusted to point to 530 * the new copy of the internal node, and the node's children's parent 531 * pointers must also be adjusted to point to the new copy. 532 * 533 * elm is a pointer to the parent element pointing at cursor.node. 534 */ 535 static int 536 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock, 537 hammer_cursor_t cursor, hammer_btree_elm_t elm) 538 { 539 struct hammer_node_lock lockroot; 540 hammer_node_t onode; 541 hammer_node_t nnode; 542 int error; 543 int i; 544 545 hammer_node_lock_init(&lockroot, cursor->node); 546 error = hammer_btree_lock_children(cursor, 1, &lockroot, NULL); 547 if (error) 548 goto done; 549 550 onode = cursor->node; 551 nnode = hammer_alloc_btree(cursor->trans, 0, &error); 552 553 if (nnode == NULL) 554 goto done; 555 556 /* 557 * Move the node. Adjust the parent's pointer to us first. 558 */ 559 hammer_lock_ex(&nnode->lock); 560 hammer_modify_node_noundo(cursor->trans, nnode); 561 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk)); 562 563 if (elm) { 564 /* 565 * We are not the root of the B-Tree 566 */ 567 hammer_modify_node(cursor->trans, cursor->parent, 568 &elm->internal.subtree_offset, 569 sizeof(elm->internal.subtree_offset)); 570 elm->internal.subtree_offset = nnode->node_offset; 571 hammer_modify_node_done(cursor->parent); 572 } else { 573 /* 574 * We are the root of the B-Tree 575 */ 576 hammer_volume_t volume; 577 578 volume = hammer_get_root_volume(cursor->trans->hmp, &error); 579 KKASSERT(error == 0); 580 581 hammer_modify_volume_field(cursor->trans, volume, 582 vol0_btree_root); 583 volume->ondisk->vol0_btree_root = nnode->node_offset; 584 hammer_modify_volume_done(volume); 585 hammer_rel_volume(volume, 0); 586 } 587 588 /* 589 * Now adjust our children's pointers to us. 590 */ 591 for (i = 0; i < nnode->ondisk->count; ++i) { 592 elm = &nnode->ondisk->elms[i]; 593 error = btree_set_parent(cursor->trans, nnode, elm); 594 if (error) 595 panic("reblock internal node: fixup problem"); 596 } 597 598 /* 599 * Clean up. 600 * 601 * The new node replaces the current node in the cursor. The cursor 602 * expects it to be locked so leave it locked. Discard onode. 603 */ 604 hammer_cursor_replaced_node(onode, nnode); 605 hammer_delete_node(cursor->trans, onode); 606 607 if (hammer_debug_general & 0x4000) { 608 kprintf("REBLOCK INODE %016llx -> %016llx\n", 609 (long long)onode->node_offset, 610 (long long)nnode->node_offset); 611 } 612 hammer_modify_node_done(nnode); 613 cursor->node = nnode; 614 615 hammer_unlock(&onode->lock); 616 hammer_rel_node(onode); 617 618 done: 619 hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL); 620 return (error); 621 } 622 623