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