sys/vfs/hammer/hammer_reblock.c

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