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 1.26 2008/07/11 01:22:29 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         int checkspace_count;
  66
  67         if ((reblock->key_beg.localization | reblock->key_end.localization) &
  68             HAMMER_LOCALIZE_PSEUDOFS_MASK) {
  69                 return(EINVAL);
  70         }
  71         if (reblock->key_beg.obj_id >= reblock->key_end.obj_id)
  72                 return(EINVAL);
  73         if (reblock->free_level < 0)
  74                 return(EINVAL);
  75
  76         reblock->key_cur = reblock->key_beg;
  77         reblock->key_cur.localization += ip->obj_localization;
  78
  79         checkspace_count = 0;
  80 retry:
  81         error = hammer_init_cursor(trans, &cursor, NULL, NULL);
  82         if (error) {
  83                 hammer_done_cursor(&cursor);
  84                 goto failed;
  85         }
  86         cursor.key_beg.localization = reblock->key_cur.localization;
  87         cursor.key_beg.obj_id = reblock->key_cur.obj_id;
  88         cursor.key_beg.key = HAMMER_MIN_KEY;
  89         cursor.key_beg.create_tid = 1;
  90         cursor.key_beg.delete_tid = 0;
  91         cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
  92         cursor.key_beg.obj_type = 0;
  93
  94         cursor.key_end.localization = reblock->key_end.localization +
  95                                       ip->obj_localization;
  96         cursor.key_end.obj_id = reblock->key_end.obj_id;
  97         cursor.key_end.key = HAMMER_MAX_KEY;
  98         cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
  99         cursor.key_end.delete_tid = 0;
 100         cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
 101         cursor.key_end.obj_type = 0;
 102
 103         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
 104         cursor.flags |= HAMMER_CURSOR_BACKEND;
 105
 106         /*
 107          * This flag allows the btree scan code to return internal nodes,
 108          * so we can reblock them in addition to the leafs.  Only specify it
 109          * if we intend to reblock B-Tree nodes.
 110          */
 111         if (reblock->head.flags & HAMMER_IOC_DO_BTREE)
 112                 cursor.flags |= HAMMER_CURSOR_REBLOCKING;
 113
 114         error = hammer_btree_first(&cursor);
 115         while (error == 0) {
 116                 /*
 117                  * Internal or Leaf node
 118                  */
 119                 elm = &cursor.node->ondisk->elms[cursor.index];
 120                 reblock->key_cur.obj_id = elm->base.obj_id;
 121                 reblock->key_cur.localization = elm->base.localization;
 122
 123                 /*
 124                  * Yield to more important tasks
 125                  */
 126                 if ((error = hammer_signal_check(trans->hmp)) != 0)
 127                         break;
 128
 129                 /*
 130                  * If we build up too much meta-data we have to wait for
 131                  * a flush cycle.
 132                  */
 133                 if (hammer_flusher_meta_limit(trans->hmp) ||
 134                     hammer_flusher_undo_exhausted(trans, 2)) {
 135                         error = EWOULDBLOCK;
 136                         break;
 137                 }
 138
 139                 /*
 140                  * If there is insufficient free space it may be due to
 141                  * reserved bigblocks, which flushing might fix.
 142                  */
 143                 if (hammer_checkspace(trans->hmp, HAMMER_CHECKSPACE_SLOP_REBLOCK)) {
 144                         if (++checkspace_count == 10) {
 145                                 error = ENOSPC;
 146                         } else {
 147                                 error = EWOULDBLOCK;
 148                         }
 149                         break;
 150                 }
 151
 152                 /*
 153                  * Acquiring the sync_lock prevents the operation from
 154                  * crossing a synchronization boundary.
 155                  *
 156                  * NOTE: cursor.node may have changed on return.
 157                  */
 158                 hammer_sync_lock_sh(trans);
 159                 error = hammer_reblock_helper(reblock, &cursor, elm);
 160                 hammer_sync_unlock(trans);
 161                 if (error == 0) {
 162                         cursor.flags |= HAMMER_CURSOR_ATEDISK;
 163                         error = hammer_btree_iterate(&cursor);
 164                 }
 165
 166         }
 167         if (error == ENOENT)
 168                 error = 0;
 169         hammer_done_cursor(&cursor);
 170         if (error == EWOULDBLOCK) {
 171                 hammer_flusher_sync(trans->hmp);
 172                 goto retry;
 173         }
 174         if (error == EDEADLK)
 175                 goto retry;
 176         if (error == EINTR) {
 177                 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
 178                 error = 0;
 179         }
 180 failed:
 181         reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
 182         return(error);
 183 }
 184
 185 /*
 186  * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
 187  *
 188  * XXX We have no visibility into internal B-Tree nodes at the moment,
 189  * only leaf nodes.
 190  */
 191 static int
 192 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
 193                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 194 {
 195         hammer_mount_t hmp;
 196         hammer_off_t tmp_offset;
 197         int error;
 198         int bytes;
 199         int cur;
 200         int iocflags;
 201
 202         error = 0;
 203         hmp = cursor->trans->hmp;
 204
 205         /*
 206          * Reblock data.  Note that data embedded in a record is reblocked
 207          * by the record reblock code.  Data processing only occurs at leaf
 208          * nodes and for RECORD element types.
 209          */
 210         if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
 211                 goto skip;
 212         if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
 213                 return(0);
 214         tmp_offset = elm->leaf.data_offset;
 215         if (tmp_offset == 0)
 216                 goto skip;
 217         if (error)
 218                 goto skip;
 219
 220         /*
 221          * NOTE: Localization restrictions may also have been set-up, we can't
 222          * just set the match flags willy-nilly here.
 223          */
 224         switch(elm->leaf.base.rec_type) {
 225         case HAMMER_RECTYPE_INODE:
 226                 iocflags = HAMMER_IOC_DO_INODES;
 227                 break;
 228         case HAMMER_RECTYPE_EXT:
 229         case HAMMER_RECTYPE_FIX:
 230         case HAMMER_RECTYPE_PFS:
 231         case HAMMER_RECTYPE_DIRENTRY:
 232                 iocflags = HAMMER_IOC_DO_DIRS;
 233                 break;
 234         case HAMMER_RECTYPE_DATA:
 235         case HAMMER_RECTYPE_DB:
 236                 iocflags = HAMMER_IOC_DO_DATA;
 237                 break;
 238         default:
 239                 iocflags = 0;
 240                 break;
 241         }
 242         if (reblock->head.flags & iocflags) {
 243                 ++reblock->data_count;
 244                 reblock->data_byte_count += elm->leaf.data_len;
 245                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 246                 if (hammer_debug_general & 0x4000)
 247                         kprintf("D %6d/%d\n", bytes, reblock->free_level);
 248                 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
 249                     bytes >= reblock->free_level) {
 250                         hammer_io_direct_uncache(hmp, &elm->leaf);
 251                         error = hammer_cursor_upgrade(cursor);
 252                         if (error == 0) {
 253                                 error = hammer_reblock_data(reblock,
 254                                                             cursor, elm);
 255                         }
 256                         if (error == 0) {
 257                                 ++reblock->data_moves;
 258                                 reblock->data_byte_moves += elm->leaf.data_len;
 259                         }
 260                 }
 261         }
 262
 263 skip:
 264         /*
 265          * Reblock a B-Tree internal or leaf node.
 266          */
 267         tmp_offset = cursor->node->node_offset;
 268         if (cursor->index == 0 &&
 269             error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
 270                 ++reblock->btree_count;
 271                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 272                 if (hammer_debug_general & 0x4000)
 273                         kprintf("B %6d/%d\n", bytes, reblock->free_level);
 274                 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
 275                     bytes >= reblock->free_level) {
 276                         error = hammer_cursor_upgrade(cursor);
 277                         if (error == 0) {
 278                                 if (cursor->parent)
 279                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 280                                 else
 281                                         elm = NULL;
 282                                 switch(cursor->node->ondisk->type) {
 283                                 case HAMMER_BTREE_TYPE_LEAF:
 284                                         error = hammer_reblock_leaf_node(
 285                                                         reblock, cursor, elm);
 286                                         break;
 287                                 case HAMMER_BTREE_TYPE_INTERNAL:
 288                                         error = hammer_reblock_int_node(
 289                                                         reblock, cursor, elm);
 290                                         break;
 291                                 default:
 292                                         panic("Illegal B-Tree node type");
 293                                 }
 294                         }
 295                         if (error == 0) {
 296                                 ++reblock->btree_moves;
 297                         }
 298                 }
 299         }
 300
 301         hammer_cursor_downgrade(cursor);
 302         return(error);
 303 }
 304
 305 /*
 306  * Reblock a record's data.  Both the B-Tree element and record pointers
 307  * to the data must be adjusted.
 308  */
 309 static int
 310 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
 311                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 312 {
 313         struct hammer_buffer *data_buffer = NULL;
 314         hammer_off_t ndata_offset;
 315         int error;
 316         void *ndata;
 317
 318         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 319                                              HAMMER_CURSOR_GET_LEAF);
 320         if (error)
 321                 return (error);
 322         ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
 323                                   elm->leaf.base.rec_type,
 324                                   &ndata_offset, &data_buffer, &error);
 325         if (error)
 326                 goto done;
 327
 328         /*
 329          * Move the data
 330          */
 331         hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
 332         bcopy(cursor->data, ndata, elm->leaf.data_len);
 333         hammer_modify_buffer_done(data_buffer);
 334
 335         hammer_blockmap_free(cursor->trans,
 336                              elm->leaf.data_offset, elm->leaf.data_len);
 337
 338         hammer_modify_node(cursor->trans, cursor->node,
 339                            &elm->leaf.data_offset, sizeof(hammer_off_t));
 340         elm->leaf.data_offset = ndata_offset;
 341         hammer_modify_node_done(cursor->node);
 342
 343 done:
 344         if (data_buffer)
 345                 hammer_rel_buffer(data_buffer, 0);
 346         return (error);
 347 }
 348
 349 /*
 350  * Reblock a B-Tree leaf node.  The parent must be adjusted to point to
 351  * the new copy of the leaf node.
 352  *
 353  * elm is a pointer to the parent element pointing at cursor.node.
 354  */
 355 static int
 356 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
 357                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 358 {
 359         hammer_node_t onode;
 360         hammer_node_t nnode;
 361         int error;
 362
 363         onode = cursor->node;
 364         nnode = hammer_alloc_btree(cursor->trans, &error);
 365
 366         if (nnode == NULL)
 367                 return (error);
 368
 369         /*
 370          * Move the node
 371          */
 372         hammer_lock_ex(&nnode->lock);
 373         hammer_modify_node_noundo(cursor->trans, nnode);
 374         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 375
 376         if (elm) {
 377                 /*
 378                  * We are not the root of the B-Tree
 379                  */
 380                 hammer_modify_node(cursor->trans, cursor->parent,
 381                                    &elm->internal.subtree_offset,
 382                                    sizeof(elm->internal.subtree_offset));
 383                 elm->internal.subtree_offset = nnode->node_offset;
 384                 hammer_modify_node_done(cursor->parent);
 385         } else {
 386                 /*
 387                  * We are the root of the B-Tree
 388                  */
 389                 hammer_volume_t volume;
 390
 391                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 392                 KKASSERT(error == 0);
 393
 394                 hammer_modify_volume_field(cursor->trans, volume,
 395                                            vol0_btree_root);
 396                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 397                 hammer_modify_volume_done(volume);
 398                 hammer_rel_volume(volume, 0);
 399         }
 400
 401         hammer_cursor_replaced_node(onode, nnode);
 402         hammer_delete_node(cursor->trans, onode);
 403
 404         if (hammer_debug_general & 0x4000) {
 405                 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
 406                         onode->node_offset, nnode->node_offset);
 407         }
 408         hammer_modify_node_done(nnode);
 409         cursor->node = nnode;
 410
 411         hammer_unlock(&onode->lock);
 412         hammer_rel_node(onode);
 413
 414         return (error);
 415 }
 416
 417 /*
 418  * Reblock a B-Tree internal node.  The parent must be adjusted to point to
 419  * the new copy of the internal node, and the node's children's parent
 420  * pointers must also be adjusted to point to the new copy.
 421  *
 422  * elm is a pointer to the parent element pointing at cursor.node.
 423  */
 424 static int
 425 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
 426                          hammer_cursor_t cursor, hammer_btree_elm_t elm)
 427 {
 428         hammer_node_locklist_t locklist = NULL;
 429         hammer_node_t onode;
 430         hammer_node_t nnode;
 431         int error;
 432         int i;
 433
 434         error = hammer_btree_lock_children(cursor, &locklist);
 435         if (error)
 436                 goto done;
 437
 438         onode = cursor->node;
 439         nnode = hammer_alloc_btree(cursor->trans, &error);
 440
 441         if (nnode == NULL)
 442                 goto done;
 443
 444         /*
 445          * Move the node.  Adjust the parent's pointer to us first.
 446          */
 447         hammer_lock_ex(&nnode->lock);
 448         hammer_modify_node_noundo(cursor->trans, nnode);
 449         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 450
 451         if (elm) {
 452                 /*
 453                  * We are not the root of the B-Tree
 454                  */
 455                 hammer_modify_node(cursor->trans, cursor->parent,
 456                                    &elm->internal.subtree_offset,
 457                                    sizeof(elm->internal.subtree_offset));
 458                 elm->internal.subtree_offset = nnode->node_offset;
 459                 hammer_modify_node_done(cursor->parent);
 460         } else {
 461                 /*
 462                  * We are the root of the B-Tree
 463                  */
 464                 hammer_volume_t volume;
 465
 466                 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
 467                 KKASSERT(error == 0);
 468
 469                 hammer_modify_volume_field(cursor->trans, volume,
 470                                            vol0_btree_root);
 471                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 472                 hammer_modify_volume_done(volume);
 473                 hammer_rel_volume(volume, 0);
 474         }
 475
 476         /*
 477          * Now adjust our children's pointers to us.
 478          */
 479         for (i = 0; i < nnode->ondisk->count; ++i) {
 480                 elm = &nnode->ondisk->elms[i];
 481                 error = btree_set_parent(cursor->trans, nnode, elm);
 482                 if (error)
 483                         panic("reblock internal node: fixup problem");
 484         }
 485
 486         /*
 487          * Clean up.
 488          *
 489          * The new node replaces the current node in the cursor.  The cursor
 490          * expects it to be locked so leave it locked.  Discard onode.
 491          */
 492         hammer_cursor_replaced_node(onode, nnode);
 493         hammer_delete_node(cursor->trans, onode);
 494
 495         if (hammer_debug_general & 0x4000) {
 496                 kprintf("REBLOCK INODE %016llx -> %016llx\n",
 497                         onode->node_offset, nnode->node_offset);
 498         }
 499         hammer_modify_node_done(nnode);
 500         cursor->node = nnode;
 501
 502         hammer_unlock(&onode->lock);
 503         hammer_rel_node(onode);
 504
 505 done:
 506         hammer_btree_unlock_children(&locklist);
 507         return (error);
 508 }
 509