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