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 1.16 2008/05/18 01:48:50 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 error;
  65
  66         if (reblock->beg_obj_id >= reblock->end_obj_id)
  67                 return(EINVAL);
  68         if (reblock->free_level < 0)
  69                 return(EINVAL);
  70
  71         reblock->cur_obj_id = reblock->beg_obj_id;
  72         reblock->cur_localization = reblock->beg_localization;
  73
  74 retry:
  75         error = hammer_init_cursor(trans, &cursor, NULL, NULL);
  76         if (error) {
  77                 hammer_done_cursor(&cursor);
  78                 return(error);
  79         }
  80         cursor.key_beg.localization = reblock->cur_localization;
  81         cursor.key_beg.obj_id = reblock->cur_obj_id;
  82         cursor.key_beg.key = HAMMER_MIN_KEY;
  83         cursor.key_beg.create_tid = 1;
  84         cursor.key_beg.delete_tid = 0;
  85         cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
  86         cursor.key_beg.obj_type = 0;
  87
  88         cursor.key_end.localization = reblock->end_localization;
  89         cursor.key_end.obj_id = reblock->end_obj_id;
  90         cursor.key_end.key = HAMMER_MAX_KEY;
  91         cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
  92         cursor.key_end.delete_tid = 0;
  93         cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
  94         cursor.key_end.obj_type = 0;
  95
  96         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
  97         cursor.flags |= HAMMER_CURSOR_BACKEND;
  98
  99         /*
 100          * This flag allows the btree scan code to return internal nodes,
 101          * so we can reblock them in addition to the leafs.  Only specify it
 102          * if we intend to reblock B-Tree nodes.
 103          */
 104         if (reblock->head.flags & HAMMER_IOC_DO_BTREE)
 105                 cursor.flags |= HAMMER_CURSOR_REBLOCKING;
 106
 107         error = hammer_btree_first(&cursor);
 108         while (error == 0) {
 109                 /*
 110                  * Internal or Leaf node
 111                  */
 112                 elm = &cursor.node->ondisk->elms[cursor.index];
 113                 reblock->cur_obj_id = elm->base.obj_id;
 114                 reblock->cur_localization = elm->base.localization;
 115
 116                 /*
 117                  * Acquiring the sync_lock prevents the operation from
 118                  * crossing a synchronization boundary.
 119                  *
 120                  * NOTE: cursor.node may have changed on return.
 121                  */
 122                 hammer_sync_lock_sh(trans);
 123                 error = hammer_reblock_helper(reblock, &cursor, elm);
 124                 hammer_sync_unlock(trans);
 125                 if (error == 0) {
 126                         cursor.flags |= HAMMER_CURSOR_ATEDISK;
 127                         error = hammer_btree_iterate(&cursor);
 128                 }
 129
 130                 /*
 131                  * Bad hack for now, don't blow out the kernel's buffer
 132                  * cache.  NOTE: We still hold locks on the cursor, we
 133                  * cannot call the flusher synchronously.
 134                  */
 135                 if (trans->hmp->locked_dirty_count +
 136                     trans->hmp->io_running_count > hammer_limit_dirtybufs) {
 137                         hammer_flusher_async(trans->hmp);
 138                         tsleep(trans, 0, "hmrslo", hz / 10);
 139                 }
 140                 if (error == 0)
 141                         error = hammer_signal_check(trans->hmp);
 142         }
 143         if (error == ENOENT)
 144                 error = 0;
 145         hammer_done_cursor(&cursor);
 146         if (error == EDEADLK)
 147                 goto retry;
 148         if (error == EINTR) {
 149                 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
 150                 error = 0;
 151         }
 152         return(error);
 153 }
 154
 155 /*
 156  * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
 157  *
 158  * XXX We have no visibility into internal B-Tree nodes at the moment,
 159  * only leaf nodes.
 160  */
 161 static int
 162 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
 163                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 164 {
 165         hammer_off_t tmp_offset;
 166         int error;
 167         int zone;
 168         int bytes;
 169         int cur;
 170
 171         error = 0;
 172
 173         /*
 174          * Reblock data.  Note that data embedded in a record is reblocked
 175          * by the record reblock code.  Data processing only occurs at leaf
 176          * nodes and for RECORD element types.
 177          */
 178         if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
 179                 goto skip;
 180         if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
 181                 return(0);
 182         tmp_offset = elm->leaf.data_offset;
 183         zone = HAMMER_ZONE_DECODE(tmp_offset);          /* can be 0 */
 184         if ((zone == HAMMER_ZONE_SMALL_DATA_INDEX ||
 185              zone == HAMMER_ZONE_LARGE_DATA_INDEX) &&
 186             error == 0 && (reblock->head.flags & (HAMMER_IOC_DO_DATA | HAMMER_IOC_DO_INODES))) {
 187                 ++reblock->data_count;
 188                 reblock->data_byte_count += elm->leaf.data_len;
 189                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 190                                                 &cur, &error);
 191                 if (hammer_debug_general & 0x4000)
 192                         kprintf("D %6d/%d\n", bytes, reblock->free_level);
 193                 if (error == 0 && cur == 0 && bytes >= reblock->free_level) {
 194                         error = hammer_cursor_upgrade(cursor);
 195                         if (error == 0) {
 196                                 error = hammer_reblock_data(reblock,
 197                                                             cursor, elm);
 198                         }
 199                         if (error == 0) {
 200                                 ++reblock->data_moves;
 201                                 reblock->data_byte_moves += elm->leaf.data_len;
 202                         }
 203                 }
 204         }
 205
 206 skip:
 207         /*
 208          * Reblock a B-Tree internal or leaf node.
 209          */
 210         tmp_offset = cursor->node->node_offset;
 211         zone = HAMMER_ZONE_DECODE(tmp_offset);
 212         if (zone == HAMMER_ZONE_BTREE_INDEX && cursor->index == 0 &&
 213             error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
 214                 ++reblock->btree_count;
 215                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 216                                                 &cur, &error);
 217                 if (hammer_debug_general & 0x4000)
 218                         kprintf("B %6d/%d\n", bytes, reblock->free_level);
 219                 if (error == 0 && cur == 0 && bytes >= reblock->free_level) {
 220                         error = hammer_cursor_upgrade(cursor);
 221                         if (error == 0) {
 222                                 if (cursor->parent)
 223                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 224                                 else
 225                                         elm = NULL;
 226                                 switch(cursor->node->ondisk->type) {
 227                                 case HAMMER_BTREE_TYPE_LEAF:
 228                                         error = hammer_reblock_leaf_node(
 229                                                         reblock, cursor, elm);
 230                                         break;
 231                                 case HAMMER_BTREE_TYPE_INTERNAL:
 232                                         error = hammer_reblock_int_node(
 233                                                         reblock, cursor, elm);
 234                                         break;
 235                                 default:
 236                                         panic("Illegal B-Tree node type");
 237                                 }
 238                         }
 239                         if (error == 0) {
 240                                 ++reblock->btree_moves;
 241                         }
 242                 }
 243         }
 244
 245         hammer_cursor_downgrade(cursor);
 246         return(error);
 247 }
 248
 249 /*
 250  * Reblock a record's data.  Both the B-Tree element and record pointers
 251  * to the data must be adjusted.
 252  */
 253 static int
 254 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
 255                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 256 {
 257         struct hammer_buffer *data_buffer = NULL;
 258         hammer_off_t ndata_offset;
 259         int error;
 260         void *ndata;
 261
 262         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 263                                              HAMMER_CURSOR_GET_LEAF);
 264         if (error)
 265                 return (error);
 266         ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
 267                                   &ndata_offset, &data_buffer, &error);
 268         if (error)
 269                 goto done;
 270
 271         /*
 272          * Move the data
 273          */
 274         hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
 275         bcopy(cursor->data, ndata, elm->leaf.data_len);
 276         hammer_modify_buffer_done(data_buffer);
 277
 278         hammer_blockmap_free(cursor->trans,
 279                              elm->leaf.data_offset, elm->leaf.data_len);
 280
 281         hammer_modify_node(cursor->trans, cursor->node,
 282                            &elm->leaf.data_offset, sizeof(hammer_off_t));
 283         elm->leaf.data_offset = ndata_offset;
 284         hammer_modify_node_done(cursor->node);
 285
 286 done:
 287         if (data_buffer)
 288                 hammer_rel_buffer(data_buffer, 0);
 289         return (error);
 290 }
 291
 292 /*
 293  * Reblock a B-Tree leaf node.  The parent must be adjusted to point to
 294  * the new copy of the leaf node.
 295  *
 296  * elm is a pointer to the parent element pointing at cursor.node.
 297  */
 298 static int
 299 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
 300                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 301 {
 302         hammer_node_t onode;
 303         hammer_node_t nnode;
 304         int error;
 305
 306         onode = cursor->node;
 307         nnode = hammer_alloc_btree(cursor->trans, &error);
 308
 309         if (nnode == NULL)
 310                 return (error);
 311
 312         /*
 313          * Move the node
 314          */
 315         hammer_lock_ex(&nnode->lock);
 316         hammer_modify_node_noundo(cursor->trans, nnode);
 317         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 318
 319         if (elm) {
 320                 /*
 321                  * We are not the root of the B-Tree
 322                  */
 323                 hammer_modify_node(cursor->trans, cursor->parent,
 324                                    &elm->internal.subtree_offset,
 325                                    sizeof(elm->internal.subtree_offset));
 326                 elm->internal.subtree_offset = nnode->node_offset;
 327                 hammer_modify_node_done(cursor->parent);
 328         } else {
 329                 /*
 330                  * We are the root of the B-Tree
 331                  */
 332                 hammer_volume_t volume;
 333
 334                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 335                 KKASSERT(error == 0);
 336
 337                 hammer_modify_volume_field(cursor->trans, volume,
 338                                            vol0_btree_root);
 339                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 340                 hammer_modify_volume_done(volume);
 341                 hammer_rel_volume(volume, 0);
 342         }
 343
 344         hammer_delete_node(cursor->trans, onode);
 345
 346         if (hammer_debug_general & 0x4000) {
 347                 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
 348                         onode->node_offset, nnode->node_offset);
 349         }
 350         hammer_modify_node_done(nnode);
 351         cursor->node = nnode;
 352
 353         hammer_unlock(&onode->lock);
 354         hammer_rel_node(onode);
 355
 356         return (error);
 357 }
 358
 359 /*
 360  * Reblock a B-Tree internal node.  The parent must be adjusted to point to
 361  * the new copy of the internal node, and the node's children's parent
 362  * pointers must also be adjusted to point to the new copy.
 363  *
 364  * elm is a pointer to the parent element pointing at cursor.node.
 365  */
 366 static int
 367 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
 368                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 369 {
 370         hammer_node_locklist_t locklist = NULL;
 371         hammer_node_t onode;
 372         hammer_node_t nnode;
 373         int error;
 374         int i;
 375
 376         error = hammer_btree_lock_children(cursor, &locklist);
 377         if (error)
 378                 goto done;
 379
 380         onode = cursor->node;
 381         nnode = hammer_alloc_btree(cursor->trans, &error);
 382
 383         if (nnode == NULL)
 384                 goto done;
 385
 386         /*
 387          * Move the node.  Adjust the parent's pointer to us first.
 388          */
 389         hammer_lock_ex(&nnode->lock);
 390         hammer_modify_node_noundo(cursor->trans, nnode);
 391         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 392
 393         if (elm) {
 394                 /*
 395                  * We are not the root of the B-Tree
 396                  */
 397                 hammer_modify_node(cursor->trans, cursor->parent,
 398                                    &elm->internal.subtree_offset,
 399                                    sizeof(elm->internal.subtree_offset));
 400                 elm->internal.subtree_offset = nnode->node_offset;
 401                 hammer_modify_node_done(cursor->parent);
 402         } else {
 403                 /*
 404                  * We are the root of the B-Tree
 405                  */
 406                 hammer_volume_t volume;
 407
 408                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 409                 KKASSERT(error == 0);
 410
 411                 hammer_modify_volume_field(cursor->trans, volume,
 412                                            vol0_btree_root);
 413                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 414                 hammer_modify_volume_done(volume);
 415                 hammer_rel_volume(volume, 0);
 416         }
 417
 418         /*
 419          * Now adjust our children's pointers to us.
 420          */
 421         for (i = 0; i < nnode->ondisk->count; ++i) {
 422                 elm = &nnode->ondisk->elms[i];
 423                 error = btree_set_parent(cursor->trans, nnode, elm);
 424                 if (error)
 425                         panic("reblock internal node: fixup problem");
 426         }
 427
 428         /*
 429          * Clean up.
 430          *
 431          * The new node replaces the current node in the cursor.  The cursor
 432          * expects it to be locked so leave it locked.  Discard onode.
 433          */
 434         hammer_delete_node(cursor->trans, onode);
 435
 436         if (hammer_debug_general & 0x4000) {
 437                 kprintf("REBLOCK INODE %016llx -> %016llx\n",
 438                         onode->node_offset, nnode->node_offset);
 439         }
 440         hammer_modify_node_done(nnode);
 441         cursor->node = nnode;
 442
 443         hammer_unlock(&onode->lock);
 444         hammer_rel_node(onode);
 445
 446 done:
 447         hammer_btree_unlock_children(&locklist);
 448         return (error);
 449 }
 450