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, 0);
 153                         hammer_flusher_wait(trans->hmp, seq);
 154                         hammer_lock_cursor(&cursor, 0);
 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, 0);
 172                         hammer_flusher_wait(trans->hmp, seq);
 173                         hammer_lock_cursor(&cursor, 0);
 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, 0);
 193                         bwillwrite(HAMMER_XBUFSIZE);
 194                         hammer_lock_cursor(&cursor, 0);
 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, 0);
 293                         hammer_io_direct_uncache(hmp, &leaf);
 294                         hammer_lock_cursor(cursor, 0);
 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.
 317          */
 318         tmp_offset = cursor->node->node_offset;
 319         if (cursor->index == 0 &&
 320             error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
 321                 ++reblock->btree_count;
 322                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 323                 if (hammer_debug_general & 0x4000)
 324                         kprintf("B %6d/%d\n", bytes, reblock->free_level);
 325                 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
 326                     bytes >= reblock->free_level) {
 327                         error = hammer_cursor_upgrade(cursor);
 328                         if (error == 0) {
 329                                 if (cursor->parent)
 330                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 331                                 else
 332                                         elm = NULL;
 333                                 switch(cursor->node->ondisk->type) {
 334                                 case HAMMER_BTREE_TYPE_LEAF:
 335                                         error = hammer_reblock_leaf_node(
 336                                                         reblock, cursor, elm);
 337                                         break;
 338                                 case HAMMER_BTREE_TYPE_INTERNAL:
 339                                         error = hammer_reblock_int_node(
 340                                                         reblock, cursor, elm);
 341                                         break;
 342                                 default:
 343                                         panic("Illegal B-Tree node type");
 344                                 }
 345                         }
 346                         if (error == 0) {
 347                                 ++reblock->btree_moves;
 348                         }
 349                 }
 350         }
 351
 352         hammer_cursor_downgrade(cursor);
 353         return(error);
 354 }
 355
 356 /*
 357  * Reblock a record's data.  Both the B-Tree element and record pointers
 358  * to the data must be adjusted.
 359  */
 360 static int
 361 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
 362                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 363 {
 364         struct hammer_buffer *data_buffer = NULL;
 365         hammer_off_t ndata_offset;
 366         int error;
 367         void *ndata;
 368
 369         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 370                                              HAMMER_CURSOR_GET_LEAF);
 371         if (error)
 372                 return (error);
 373         ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
 374                                   elm->leaf.base.rec_type,
 375                                   &ndata_offset, &data_buffer, &error);
 376         if (error)
 377                 goto done;
 378
 379         /*
 380          * Move the data
 381          */
 382         hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
 383         bcopy(cursor->data, ndata, elm->leaf.data_len);
 384         hammer_modify_buffer_done(data_buffer);
 385
 386         hammer_blockmap_free(cursor->trans,
 387                              elm->leaf.data_offset, elm->leaf.data_len);
 388
 389         hammer_modify_node(cursor->trans, cursor->node,
 390                            &elm->leaf.data_offset, sizeof(hammer_off_t));
 391         elm->leaf.data_offset = ndata_offset;
 392         hammer_modify_node_done(cursor->node);
 393
 394 done:
 395         if (data_buffer)
 396                 hammer_rel_buffer(data_buffer, 0);
 397         return (error);
 398 }
 399
 400 /*
 401  * Reblock a B-Tree leaf node.  The parent must be adjusted to point to
 402  * the new copy of the leaf node.
 403  *
 404  * elm is a pointer to the parent element pointing at cursor.node.
 405  */
 406 static int
 407 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
 408                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 409 {
 410         hammer_node_t onode;
 411         hammer_node_t nnode;
 412         int error;
 413
 414         onode = cursor->node;
 415         nnode = hammer_alloc_btree(cursor->trans, &error);
 416
 417         if (nnode == NULL)
 418                 return (error);
 419
 420         /*
 421          * Move the node
 422          */
 423         hammer_lock_ex(&nnode->lock);
 424         hammer_modify_node_noundo(cursor->trans, nnode);
 425         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 426
 427         if (elm) {
 428                 /*
 429                  * We are not the root of the B-Tree
 430                  */
 431                 hammer_modify_node(cursor->trans, cursor->parent,
 432                                    &elm->internal.subtree_offset,
 433                                    sizeof(elm->internal.subtree_offset));
 434                 elm->internal.subtree_offset = nnode->node_offset;
 435                 hammer_modify_node_done(cursor->parent);
 436         } else {
 437                 /*
 438                  * We are the root of the B-Tree
 439                  */
 440                 hammer_volume_t volume;
 441
 442                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 443                 KKASSERT(error == 0);
 444
 445                 hammer_modify_volume_field(cursor->trans, volume,
 446                                            vol0_btree_root);
 447                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 448                 hammer_modify_volume_done(volume);
 449                 hammer_rel_volume(volume, 0);
 450         }
 451
 452         hammer_cursor_replaced_node(onode, nnode);
 453         hammer_delete_node(cursor->trans, onode);
 454
 455         if (hammer_debug_general & 0x4000) {
 456                 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
 457                         onode->node_offset, nnode->node_offset);
 458         }
 459         hammer_modify_node_done(nnode);
 460         cursor->node = nnode;
 461
 462         hammer_unlock(&onode->lock);
 463         hammer_rel_node(onode);
 464
 465         return (error);
 466 }
 467
 468 /*
 469  * Reblock a B-Tree internal node.  The parent must be adjusted to point to
 470  * the new copy of the internal node, and the node's children's parent
 471  * pointers must also be adjusted to point to the new copy.
 472  *
 473  * elm is a pointer to the parent element pointing at cursor.node.
 474  */
 475 static int
 476 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
 477                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 478 {
 479         hammer_node_locklist_t locklist = NULL;
 480         hammer_node_t onode;
 481         hammer_node_t nnode;
 482         int error;
 483         int i;
 484
 485         error = hammer_btree_lock_children(cursor, &locklist);
 486         if (error)
 487                 goto done;
 488
 489         onode = cursor->node;
 490         nnode = hammer_alloc_btree(cursor->trans, &error);
 491
 492         if (nnode == NULL)
 493                 goto done;
 494
 495         /*
 496          * Move the node.  Adjust the parent's pointer to us first.
 497          */
 498         hammer_lock_ex(&nnode->lock);
 499         hammer_modify_node_noundo(cursor->trans, nnode);
 500         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 501
 502         if (elm) {
 503                 /*
 504                  * We are not the root of the B-Tree
 505                  */
 506                 hammer_modify_node(cursor->trans, cursor->parent,
 507                                    &elm->internal.subtree_offset,
 508                                    sizeof(elm->internal.subtree_offset));
 509                 elm->internal.subtree_offset = nnode->node_offset;
 510                 hammer_modify_node_done(cursor->parent);
 511         } else {
 512                 /*
 513                  * We are the root of the B-Tree
 514                  */
 515                 hammer_volume_t volume;
 516
 517                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 518                 KKASSERT(error == 0);
 519
 520                 hammer_modify_volume_field(cursor->trans, volume,
 521                                            vol0_btree_root);
 522                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 523                 hammer_modify_volume_done(volume);
 524                 hammer_rel_volume(volume, 0);
 525         }
 526
 527         /*
 528          * Now adjust our children's pointers to us.
 529          */
 530         for (i = 0; i < nnode->ondisk->count; ++i) {
 531                 elm = &nnode->ondisk->elms[i];
 532                 error = btree_set_parent(cursor->trans, nnode, elm);
 533                 if (error)
 534                         panic("reblock internal node: fixup problem");
 535         }
 536
 537         /*
 538          * Clean up.
 539          *
 540          * The new node replaces the current node in the cursor.  The cursor
 541          * expects it to be locked so leave it locked.  Discard onode.
 542          */
 543         hammer_cursor_replaced_node(onode, nnode);
 544         hammer_delete_node(cursor->trans, onode);
 545
 546         if (hammer_debug_general & 0x4000) {
 547                 kprintf("REBLOCK INODE %016llx -> %016llx\n",
 548                         onode->node_offset, nnode->node_offset);
 549         }
 550         hammer_modify_node_done(nnode);
 551         cursor->node = nnode;
 552
 553         hammer_unlock(&onode->lock);
 554         hammer_rel_node(onode);
 555
 556 done:
 557         hammer_btree_unlock_children(cursor, &locklist);
 558         return (error);
 559 }
 560