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 1.11 2008/05/05 20:34:48 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         if (error == EINTR) {
 126                 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
 127                 error = 0;
 128         }
 129         return(error);
 130 }
 131
 132 /*
 133  * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
 134  *
 135  * XXX We have no visibility into internal B-Tree nodes at the moment,
 136  * only leaf nodes.
 137  */
 138 static int
 139 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
 140                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 141 {
 142         hammer_off_t tmp_offset;
 143         int error;
 144         int zone;
 145         int bytes;
 146         int cur;
 147
 148         if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
 149                 return(0);
 150         error = 0;
 151
 152         /*
 153          * Reblock data.  Note that data embedded in a record is reblocked
 154          * by the record reblock code.
 155          */
 156         tmp_offset = elm->leaf.data_offset;
 157         zone = HAMMER_ZONE_DECODE(tmp_offset);          /* can be 0 */
 158         if ((zone == HAMMER_ZONE_SMALL_DATA_INDEX ||
 159              zone == HAMMER_ZONE_LARGE_DATA_INDEX) && error == 0) {
 160                 ++reblock->data_count;
 161                 reblock->data_byte_count += elm->leaf.data_len;
 162                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 163                                                 &cur, &error);
 164                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 165                         if (hammer_debug_general & 0x4000)
 166                                 kprintf("%6d ", bytes);
 167                         error = hammer_cursor_upgrade(cursor);
 168                         if (error == 0) {
 169                                 error = hammer_reblock_data(reblock,
 170                                                             cursor, elm);
 171                         }
 172                         if (error == 0) {
 173                                 ++reblock->data_moves;
 174                                 reblock->data_byte_moves += elm->leaf.data_len;
 175                         }
 176                 }
 177         }
 178
 179         /*
 180          * Reblock a record
 181          */
 182         tmp_offset = elm->leaf.rec_offset;
 183         zone = HAMMER_ZONE_DECODE(tmp_offset);
 184         if (zone == HAMMER_ZONE_RECORD_INDEX && error == 0) {
 185                 ++reblock->record_count;
 186                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 187                                                 &cur, &error);
 188                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 189                         if (hammer_debug_general & 0x4000)
 190                                 kprintf("%6d ", bytes);
 191                         error = hammer_cursor_upgrade(cursor);
 192                         if (error == 0) {
 193                                 error = hammer_reblock_record(reblock,
 194                                                               cursor, elm);
 195                         }
 196                         if (error == 0) {
 197                                 ++reblock->record_moves;
 198                         }
 199                 }
 200         }
 201
 202         /*
 203          * Reblock a B-Tree node.  Adjust elm to point at the parent's
 204          * leaf entry.
 205          */
 206         tmp_offset = cursor->node->node_offset;
 207         zone = HAMMER_ZONE_DECODE(tmp_offset);
 208         if (zone == HAMMER_ZONE_BTREE_INDEX && error == 0 &&
 209             cursor->index == 0) {
 210                 ++reblock->btree_count;
 211                 bytes = hammer_blockmap_getfree(cursor->trans->hmp, tmp_offset,
 212                                                 &cur, &error);
 213                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 214                         if (hammer_debug_general & 0x4000)
 215                                 kprintf("%6d ", bytes);
 216                         error = hammer_cursor_upgrade(cursor);
 217                         if (error == 0) {
 218                                 if (cursor->parent)
 219                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 220                                 else
 221                                         elm = NULL;
 222                                 error = hammer_reblock_node(reblock,
 223                                                             cursor, elm);
 224                         }
 225                         if (error == 0) {
 226                                 ++reblock->btree_moves;
 227                         }
 228                 }
 229         }
 230
 231         hammer_cursor_downgrade(cursor);
 232         return(error);
 233 }
 234
 235 /*
 236  * Reblock a record's data.  Both the B-Tree element and record pointers
 237  * to the data must be adjusted.
 238  */
 239 static int
 240 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
 241                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 242 {
 243         struct hammer_buffer *data_buffer = NULL;
 244         hammer_off_t ndata_offset;
 245         int error;
 246         void *ndata;
 247
 248         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 249                                              HAMMER_CURSOR_GET_RECORD);
 250         if (error)
 251                 return (error);
 252         ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
 253                                   &ndata_offset, &data_buffer, &error);
 254         if (error)
 255                 goto done;
 256
 257         /*
 258          * Move the data
 259          */
 260         hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
 261         bcopy(cursor->data, ndata, elm->leaf.data_len);
 262         hammer_modify_buffer_done(data_buffer);
 263
 264         hammer_blockmap_free(cursor->trans,
 265                              elm->leaf.data_offset, elm->leaf.data_len);
 266
 267         hammer_modify_record_field(cursor->trans, cursor->record_buffer,
 268                                    cursor->record, base.data_off, 0);
 269         cursor->record->base.data_off = ndata_offset;
 270         hammer_modify_record_done(cursor->record_buffer, cursor->record);
 271
 272         hammer_modify_node(cursor->trans, cursor->node,
 273                            &elm->leaf.data_offset, sizeof(hammer_off_t));
 274         elm->leaf.data_offset = ndata_offset;
 275         hammer_modify_node_done(cursor->node);
 276
 277 done:
 278         if (data_buffer)
 279                 hammer_rel_buffer(data_buffer, 0);
 280         return (error);
 281 }
 282
 283 /*
 284  * Reblock a record.  The B-Tree must be adjusted to point to the new record
 285  * and the existing record must be physically destroyed so a FS rebuild
 286  * does not see two versions of the same record.
 287  */
 288 static int
 289 hammer_reblock_record(struct hammer_ioc_reblock *reblock,
 290                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 291 {
 292         struct hammer_buffer *rec_buffer = NULL;
 293         hammer_off_t nrec_offset;
 294         hammer_off_t ndata_offset;
 295         hammer_record_ondisk_t orec;
 296         hammer_record_ondisk_t nrec;
 297         int error;
 298         int inline_data;
 299
 300         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_RECORD);
 301         if (error)
 302                 return (error);
 303
 304         nrec = hammer_alloc_record(cursor->trans, &nrec_offset,
 305                                    elm->leaf.base.rec_type, &rec_buffer,
 306                                    0, NULL, NULL, NULL, &error);
 307         if (error)
 308                 goto done;
 309
 310         /*
 311          * Move the record.  Check for an inline data reference and move that
 312          * too if necessary.
 313          */
 314         orec = cursor->record;
 315         hammer_modify_buffer(cursor->trans, rec_buffer, NULL, 0);
 316         bcopy(orec, nrec, sizeof(*nrec));
 317
 318         if ((orec->base.data_off & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_RECORD) {
 319                 ndata_offset = orec->base.data_off - elm->leaf.rec_offset;
 320                 KKASSERT(ndata_offset < sizeof(*nrec));
 321                 ndata_offset += nrec_offset;
 322                 inline_data = 1;
 323         } else {
 324                 ndata_offset = 0;
 325                 inline_data = 0;
 326         }
 327         hammer_modify_record_field(cursor->trans, cursor->record_buffer,
 328                                    orec, base.base.rec_type, 1);
 329         orec->base.base.rec_type |= HAMMER_RECTYPE_MOVED;
 330         orec->base.signature = HAMMER_RECORD_SIGNATURE_DESTROYED;
 331         hammer_modify_record_done(cursor->record_buffer, orec);
 332
 333         hammer_blockmap_free(cursor->trans,
 334                              elm->leaf.rec_offset, sizeof(*nrec));
 335
 336         if (hammer_debug_general & 0x4000) {
 337                 kprintf("REBLOCK RECD %016llx -> %016llx\n",
 338                         elm->leaf.rec_offset, nrec_offset);
 339         }
 340
 341         hammer_modify_node(cursor->trans, cursor->node,
 342                            &elm->leaf.rec_offset, sizeof(hammer_off_t));
 343         elm->leaf.rec_offset = nrec_offset;
 344         hammer_modify_node_done(cursor->node);
 345         if (inline_data) {
 346                 hammer_modify_node(cursor->trans, cursor->node,
 347                                  &elm->leaf.data_offset, sizeof(hammer_off_t));
 348                 elm->leaf.data_offset = ndata_offset;
 349                 hammer_modify_node_done(cursor->node);
 350                 nrec->base.data_off = ndata_offset;
 351         }
 352         hammer_modify_buffer_done(rec_buffer);
 353
 354 done:
 355         if (rec_buffer)
 356                 hammer_rel_buffer(rec_buffer, 0);
 357         return (error);
 358 }
 359
 360 /*
 361  * Reblock a B-Tree (leaf) node.  The parent must be adjusted to point to
 362  * the new copy of the leaf node.  elm is a pointer to the parent element
 363  * pointing at cursor.node.
 364  *
 365  * XXX reblock internal nodes too.
 366  */
 367 static int
 368 hammer_reblock_node(struct hammer_ioc_reblock *reblock,
 369                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 370 {
 371         hammer_node_t onode;
 372         hammer_node_t nnode;
 373         int error;
 374
 375         onode = cursor->node;
 376         nnode = hammer_alloc_btree(cursor->trans, &error);
 377         hammer_lock_ex(&nnode->lock);
 378
 379         if (nnode == NULL)
 380                 return (error);
 381
 382         /*
 383          * Move the node
 384          */
 385         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 386
 387         if (elm) {
 388                 /*
 389                  * We are not the root of the B-Tree
 390                  */
 391                 hammer_modify_node(cursor->trans, cursor->parent,
 392                                    &elm->internal.subtree_offset,
 393                                    sizeof(elm->internal.subtree_offset));
 394                 elm->internal.subtree_offset = nnode->node_offset;
 395                 hammer_modify_node_done(cursor->parent);
 396         } else {
 397                 /*
 398                  * We are the root of the B-Tree
 399                  */
 400                 hammer_volume_t volume;
 401
 402                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 403                 KKASSERT(error == 0);
 404
 405                 hammer_modify_volume_field(cursor->trans, volume,
 406                                            vol0_btree_root);
 407                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 408                 hammer_modify_volume_done(volume);
 409                 hammer_rel_volume(volume, 0);
 410         }
 411
 412         hammer_delete_node(cursor->trans, onode);
 413
 414         if (hammer_debug_general & 0x4000) {
 415                 kprintf("REBLOCK NODE %016llx -> %016llx\n",
 416                         onode->node_offset, nnode->node_offset);
 417         }
 418
 419         cursor->node = nnode;
 420         hammer_rel_node(onode);
 421
 422         return (error);
 423 }
 424