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 1.10 2008/05/03 20:21:20 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_record(struct hammer_ioc_reblock *reblock,
  54                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  55 static int hammer_reblock_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 retry:
  72         error = hammer_init_cursor(trans, &cursor, NULL, NULL);
  73         if (error) {
  74                 hammer_done_cursor(&cursor);
  75                 return(error);
  76         }
  77         cursor.key_beg.obj_id = reblock->cur_obj_id;
  78         cursor.key_beg.key = HAMMER_MIN_KEY;
  79         cursor.key_beg.create_tid = 1;
  80         cursor.key_beg.delete_tid = 0;
  81         cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
  82         cursor.key_beg.obj_type = 0;
  83
  84         cursor.key_end.obj_id = reblock->end_obj_id;
  85         cursor.key_end.key = HAMMER_MAX_KEY;
  86         cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
  87         cursor.key_end.delete_tid = 0;
  88         cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
  89         cursor.key_end.obj_type = 0;
  90
  91         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
  92         cursor.flags |= HAMMER_CURSOR_BACKEND;
  93
  94         error = hammer_btree_first(&cursor);
  95         while (error == 0) {
  96                 elm = &cursor.node->ondisk->elms[cursor.index];
  97                 reblock->cur_obj_id = elm->base.obj_id;
  98
  99                 /*
 100                  * Acquiring the sync_lock prevents the operation from
 101                  * crossing a synchronization boundary.
 102                  */
 103                 hammer_lock_ex(&trans->hmp->sync_lock);
 104                 error = hammer_reblock_helper(reblock, &cursor, elm);
 105                 hammer_unlock(&trans->hmp->sync_lock);
 106                 if (error == 0) {
 107                         cursor.flags |= HAMMER_CURSOR_ATEDISK;
 108                         error = hammer_btree_iterate(&cursor);
 109                 }
 110
 111                 /*
 112                  * Bad hack for now, don't blow out the kernel's buffer
 113                  * cache.
 114                  */
 115                 if (trans->hmp->locked_dirty_count > hammer_limit_dirtybufs)
 116                         hammer_flusher_sync(trans->hmp);
 117                 if (error == 0)
 118                         error = hammer_signal_check(trans->hmp);
 119         }
 120         if (error == ENOENT)
 121                 error = 0;
 122         hammer_done_cursor(&cursor);
 123         if (error == EDEADLK)
 124                 goto retry;
 125         return(error);
 126 }
 127
 128 /*
 129  * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
 130  *
 131  * XXX We have no visibility into internal B-Tree nodes at the moment,
 132  * only leaf nodes.
 133  */
 134 static int
 135 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
 136                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 137 {
 138         hammer_off_t tmp_offset;
 139         int error;
 140         int zone;
 141         int bytes;
 142         int cur;
 143
 144         if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
 145                 return(0);
 146         error = 0;
 147
 148         /*
 149          * Reblock data.  Note that data embedded in a record is reblocked
 150          * by the record reblock code.
 151          */
 152         tmp_offset = elm->leaf.data_offset;
 153         zone = HAMMER_ZONE_DECODE(tmp_offset);          /* can be 0 */
 154         if ((zone == HAMMER_ZONE_SMALL_DATA_INDEX ||
 155              zone == HAMMER_ZONE_LARGE_DATA_INDEX) && error == 0) {
 156                 ++reblock->data_count;
 157                 reblock->data_byte_count += elm->leaf.data_len;
 158                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 159                                                 &cur, &error);
 160                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 161                         if (hammer_debug_general & 0x4000)
 162                                 kprintf("%6d ", bytes);
 163                         error = hammer_cursor_upgrade(cursor);
 164                         if (error == 0) {
 165                                 error = hammer_reblock_data(reblock,
 166                                                             cursor, elm);
 167                         }
 168                         if (error == 0) {
 169                                 ++reblock->data_moves;
 170                                 reblock->data_byte_moves += elm->leaf.data_len;
 171                         }
 172                 }
 173         }
 174
 175         /*
 176          * Reblock a record
 177          */
 178         tmp_offset = elm->leaf.rec_offset;
 179         zone = HAMMER_ZONE_DECODE(tmp_offset);
 180         if (zone == HAMMER_ZONE_RECORD_INDEX && error == 0) {
 181                 ++reblock->record_count;
 182                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 183                                                 &cur, &error);
 184                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 185                         if (hammer_debug_general & 0x4000)
 186                                 kprintf("%6d ", bytes);
 187                         error = hammer_cursor_upgrade(cursor);
 188                         if (error == 0) {
 189                                 error = hammer_reblock_record(reblock,
 190                                                               cursor, elm);
 191                         }
 192                         if (error == 0) {
 193                                 ++reblock->record_moves;
 194                         }
 195                 }
 196         }
 197
 198         /*
 199          * Reblock a B-Tree node.  Adjust elm to point at the parent's
 200          * leaf entry.
 201          */
 202         tmp_offset = cursor->node->node_offset;
 203         zone = HAMMER_ZONE_DECODE(tmp_offset);
 204         if (zone == HAMMER_ZONE_BTREE_INDEX && error == 0 &&
 205             cursor->index == 0) {
 206                 ++reblock->btree_count;
 207                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 208                                                 &cur, &error);
 209                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 210                         if (hammer_debug_general & 0x4000)
 211                                 kprintf("%6d ", bytes);
 212                         error = hammer_cursor_upgrade(cursor);
 213                         if (error == 0) {
 214                                 if (cursor->parent)
 215                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 216                                 else
 217                                         elm = NULL;
 218                                 error = hammer_reblock_node(reblock,
 219                                                             cursor, elm);
 220                         }
 221                         if (error == 0) {
 222                                 ++reblock->btree_moves;
 223                         }
 224                 }
 225         }
 226
 227         hammer_cursor_downgrade(cursor);
 228         return(error);
 229 }
 230
 231 /*
 232  * Reblock a record's data.  Both the B-Tree element and record pointers
 233  * to the data must be adjusted.
 234  */
 235 static int
 236 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
 237                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 238 {
 239         struct hammer_buffer *data_buffer = NULL;
 240         hammer_off_t ndata_offset;
 241         int error;
 242         void *ndata;
 243
 244         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 245                                              HAMMER_CURSOR_GET_RECORD);
 246         if (error)
 247                 return (error);
 248         ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
 249                                   &ndata_offset, &data_buffer, &error);
 250         if (error)
 251                 goto done;
 252
 253         /*
 254          * Move the data
 255          */
 256         hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
 257         bcopy(cursor->data, ndata, elm->leaf.data_len);
 258         hammer_modify_buffer_done(data_buffer);
 259
 260         hammer_blockmap_free(cursor->trans,
 261                              elm->leaf.data_offset, elm->leaf.data_len);
 262
 263         hammer_modify_record(cursor->trans, cursor->record_buffer,
 264                              &cursor->record->base.data_off,
 265                              sizeof(hammer_off_t));
 266         cursor->record->base.data_off = ndata_offset;
 267         hammer_modify_record_done(cursor->record_buffer);
 268
 269         hammer_modify_node(cursor->trans, cursor->node,
 270                            &elm->leaf.data_offset, sizeof(hammer_off_t));
 271         elm->leaf.data_offset = ndata_offset;
 272         hammer_modify_node_done(cursor->node);
 273
 274 done:
 275         if (data_buffer)
 276                 hammer_rel_buffer(data_buffer, 0);
 277         return (error);
 278 }
 279
 280 /*
 281  * Reblock a record.  The B-Tree must be adjusted to point to the new record
 282  * and the existing record must be physically destroyed so a FS rebuild
 283  * does not see two versions of the same record.
 284  */
 285 static int
 286 hammer_reblock_record(struct hammer_ioc_reblock *reblock,
 287                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 288 {
 289         struct hammer_buffer *rec_buffer = NULL;
 290         hammer_off_t nrec_offset;
 291         hammer_off_t ndata_offset;
 292         hammer_record_ondisk_t orec;
 293         hammer_record_ondisk_t nrec;
 294         int error;
 295         int inline_data;
 296
 297         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_RECORD);
 298         if (error)
 299                 return (error);
 300
 301         nrec = hammer_alloc_record(cursor->trans, &nrec_offset,
 302                                    elm->leaf.base.rec_type, &rec_buffer,
 303                                    0, NULL, NULL, &error);
 304         if (error)
 305                 goto done;
 306
 307         /*
 308          * Move the record.  Check for an inline data reference and move that
 309          * too if necessary.
 310          */
 311         orec = cursor->record;
 312         hammer_modify_buffer(cursor->trans, rec_buffer, NULL, 0);
 313         bcopy(orec, nrec, sizeof(*nrec));
 314
 315         if ((orec->base.data_off & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_RECORD) {
 316                 ndata_offset = orec->base.data_off - elm->leaf.rec_offset;
 317                 KKASSERT(ndata_offset < sizeof(*nrec));
 318                 ndata_offset += nrec_offset;
 319                 inline_data = 1;
 320         } else {
 321                 ndata_offset = 0;
 322                 inline_data = 0;
 323         }
 324
 325         hammer_modify_record(cursor->trans, cursor->record_buffer,
 326                              &orec->base.base.rec_type,
 327                              sizeof(orec->base.base.rec_type));
 328         orec->base.base.rec_type |= HAMMER_RECTYPE_MOVED;
 329         hammer_modify_record_done(cursor->record_buffer);
 330
 331         hammer_blockmap_free(cursor->trans,
 332                              elm->leaf.rec_offset, sizeof(*nrec));
 333
 334         if (hammer_debug_general & 0x4000) {
 335                 kprintf("REBLOCK RECD %016llx -> %016llx\n",
 336                         elm->leaf.rec_offset, nrec_offset);
 337         }
 338
 339         hammer_modify_node(cursor->trans, cursor->node,
 340                            &elm->leaf.rec_offset, sizeof(hammer_off_t));
 341         elm->leaf.rec_offset = nrec_offset;
 342         hammer_modify_node_done(cursor->node);
 343         if (inline_data) {
 344                 hammer_modify_node(cursor->trans, cursor->node,
 345                                  &elm->leaf.data_offset, sizeof(hammer_off_t));
 346                 elm->leaf.data_offset = ndata_offset;
 347                 hammer_modify_node_done(cursor->node);
 348                 nrec->base.data_off = ndata_offset;
 349         }
 350         hammer_modify_buffer_done(rec_buffer);
 351
 352 done:
 353         if (rec_buffer)
 354                 hammer_rel_buffer(rec_buffer, 0);
 355         return (error);
 356 }
 357
 358 /*
 359  * Reblock a B-Tree (leaf) node.  The parent must be adjusted to point to
 360  * the new copy of the leaf node.  elm is a pointer to the parent element
 361  * pointing at cursor.node.
 362  *
 363  * XXX reblock internal nodes too.
 364  */
 365 static int
 366 hammer_reblock_node(struct hammer_ioc_reblock *reblock,
 367                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 368 {
 369         hammer_node_t onode;
 370         hammer_node_t nnode;
 371         int error;
 372
 373         onode = cursor->node;
 374         nnode = hammer_alloc_btree(cursor->trans, &error);
 375         hammer_lock_ex(&nnode->lock);
 376
 377         if (nnode == NULL)
 378                 return (error);
 379
 380         /*
 381          * Move the node
 382          */
 383         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 384
 385         if (elm) {
 386                 /*
 387                  * We are not the root of the B-Tree
 388                  */
 389                 hammer_modify_node(cursor->trans, cursor->parent,
 390                                    &elm->internal.subtree_offset,
 391                                    sizeof(elm->internal.subtree_offset));
 392                 elm->internal.subtree_offset = nnode->node_offset;
 393                 hammer_modify_node_done(cursor->parent);
 394         } else {
 395                 /*
 396                  * We are the root of the B-Tree
 397                  */
 398                 hammer_volume_t volume;
 399
 400                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 401                 KKASSERT(error == 0);
 402
 403                 hammer_modify_volume_field(cursor->trans, volume,
 404                                            vol0_btree_root);
 405                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 406                 hammer_modify_volume_done(volume);
 407                 hammer_rel_volume(volume, 0);
 408         }
 409
 410         hammer_delete_node(cursor->trans, onode);
 411
 412         if (hammer_debug_general & 0x4000) {
 413                 kprintf("REBLOCK NODE %016llx -> %016llx\n",
 414                         onode->node_offset, nnode->node_offset);
 415         }
 416
 417         cursor->node = nnode;
 418         hammer_rel_node(onode);
 419
 420         return (error);
 421 }
 422