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 1.1 2008/03/18 05:19:16 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(hammer_mount_t hmp,
  49                                  struct hammer_ioc_reblock *reblock,
  50                                  hammer_cursor_t cursor,
  51                                  hammer_btree_elm_t elm);
  52 static int hammer_reblock_data(hammer_mount_t hmp,
  53                                 struct hammer_ioc_reblock *reblock,
  54                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  55 static int hammer_reblock_record(hammer_mount_t hmp,
  56                                 struct hammer_ioc_reblock *reblock,
  57                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  58 static int hammer_reblock_node(hammer_mount_t hmp,
  59                                 struct hammer_ioc_reblock *reblock,
  60                                 hammer_cursor_t cursor, hammer_btree_elm_t elm);
  61
  62 int
  63 hammer_reblock(hammer_inode_t ip, struct hammer_ioc_reblock *reblock)
  64 {
  65         struct hammer_cursor cursor;
  66         hammer_btree_elm_t elm;
  67         int error;
  68
  69         if (reblock->beg_obj_id >= reblock->end_obj_id)
  70                 return(EINVAL);
  71         if (reblock->free_level < 0)
  72                 return(EINVAL);
  73
  74 retry:
  75         error = hammer_init_cursor_hmp(&cursor, NULL, ip->hmp);
  76         if (error) {
  77                 hammer_done_cursor(&cursor);
  78                 return(error);
  79         }
  80         cursor.key_beg.obj_id = reblock->cur_obj_id;
  81         cursor.key_beg.key = HAMMER_MIN_KEY;
  82         cursor.key_beg.create_tid = 1;
  83         cursor.key_beg.delete_tid = 0;
  84         cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
  85         cursor.key_beg.obj_type = 0;
  86
  87         cursor.key_end.obj_id = reblock->end_obj_id;
  88         cursor.key_end.key = HAMMER_MAX_KEY;
  89         cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
  90         cursor.key_end.delete_tid = 0;
  91         cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
  92         cursor.key_end.obj_type = 0;
  93
  94         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
  95
  96         error = hammer_btree_first(&cursor);
  97         while (error == 0) {
  98                 elm = &cursor.node->ondisk->elms[cursor.index];
  99                 reblock->cur_obj_id = elm->base.obj_id;
 100
 101                 error = hammer_reblock_helper(ip->hmp, reblock, &cursor, elm);
 102                 if (error == 0) {
 103                         cursor.flags |= HAMMER_CURSOR_ATEDISK;
 104                         error = hammer_btree_iterate(&cursor);
 105                 }
 106         }
 107         if (error == ENOENT)
 108                 error = 0;
 109         hammer_done_cursor(&cursor);
 110         if (error == EDEADLK)
 111                 goto retry;
 112         return(error);
 113 }
 114
 115 /*
 116  * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
 117  *
 118  * XXX We have no visibility into internal B-Tree nodes at the moment.
 119  */
 120 static int
 121 hammer_reblock_helper(hammer_mount_t hmp, struct hammer_ioc_reblock *reblock,
 122                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 123 {
 124         hammer_off_t tmp_offset;
 125         int error;
 126         int zone;
 127         int bytes;
 128         int cur;
 129
 130         if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
 131                 return(0);
 132         error = 0;
 133
 134         /*
 135          * Reblock data.  Note that data embedded in a record is reblocked
 136          * by the record reblock code.
 137          */
 138         tmp_offset = elm->leaf.data_offset;
 139         zone = HAMMER_ZONE_DECODE(tmp_offset);          /* can be 0 */
 140         if ((zone == HAMMER_ZONE_SMALL_DATA_INDEX ||
 141              zone == HAMMER_ZONE_LARGE_DATA_INDEX) && error == 0) {
 142                 ++reblock->data_count;
 143                 reblock->data_byte_count += elm->leaf.data_len;
 144                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 145                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 146                         kprintf("%6d ", bytes);
 147                         error = hammer_cursor_upgrade(cursor);
 148                         if (error == 0) {
 149                                 error = hammer_reblock_data(hmp, reblock,
 150                                                             cursor, elm);
 151                         }
 152                         if (error == 0) {
 153                                 ++reblock->data_moves;
 154                                 reblock->data_byte_moves += elm->leaf.data_len;
 155                         }
 156                 }
 157         }
 158
 159         /*
 160          * Reblock a record
 161          */
 162         tmp_offset = elm->leaf.rec_offset;
 163         zone = HAMMER_ZONE_DECODE(tmp_offset);
 164         if (zone == HAMMER_ZONE_RECORD_INDEX && error == 0) {
 165                 ++reblock->record_count;
 166                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 167                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 168                         kprintf("%6d ", bytes);
 169                         error = hammer_cursor_upgrade(cursor);
 170                         if (error == 0) {
 171                                 error = hammer_reblock_record(hmp, reblock,
 172                                                               cursor, elm);
 173                         }
 174                         if (error == 0) {
 175                                 ++reblock->record_moves;
 176                         }
 177                 }
 178         }
 179
 180         /*
 181          * Reblock a B-Tree node.  Adjust elm to point at the parent's
 182          * leaf entry.
 183          */
 184         tmp_offset = cursor->node->node_offset;
 185         zone = HAMMER_ZONE_DECODE(tmp_offset);
 186         if (zone == HAMMER_ZONE_BTREE_INDEX && error == 0 &&
 187             cursor->index == 0) {
 188                 ++reblock->btree_count;
 189                 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
 190                 if (error == 0 && cur == 0 && bytes > reblock->free_level) {
 191                         kprintf("%6d ", bytes);
 192                         error = hammer_cursor_upgrade(cursor);
 193                         if (error == 0) {
 194                                 if (cursor->parent)
 195                                         elm = &cursor->parent->ondisk->elms[cursor->parent_index];
 196                                 else
 197                                         elm = NULL;
 198                                 error = hammer_reblock_node(hmp, reblock,
 199                                                             cursor, elm);
 200                         }
 201                         if (error == 0) {
 202                                 ++reblock->btree_moves;
 203                         }
 204                 }
 205         }
 206
 207         hammer_cursor_downgrade(cursor);
 208         return(error);
 209 }
 210
 211 /*
 212  * Reblock a record's data.  Both the B-Tree element and record pointers
 213  * to the data must be adjusted.
 214  */
 215 static int
 216 hammer_reblock_data(hammer_mount_t hmp, struct hammer_ioc_reblock *reblock,
 217                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 218 {
 219         struct hammer_buffer *data_buffer = NULL;
 220         hammer_off_t ndata_offset;
 221         int error;
 222         void *ndata;
 223
 224         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
 225                                              HAMMER_CURSOR_GET_RECORD);
 226         if (error)
 227                 return (error);
 228         ndata = hammer_alloc_data(hmp, elm->leaf.data_len, &ndata_offset,
 229                                   &data_buffer, &error);
 230         if (error)
 231                 goto done;
 232
 233         /*
 234          * Move the data
 235          */
 236         bcopy(cursor->data, ndata, elm->leaf.data_len);
 237         hammer_modify_node(cursor->node,
 238                 &elm->leaf.data_offset, sizeof(hammer_off_t));
 239         hammer_modify_record(cursor->record_buffer,
 240                 &cursor->record->base.data_off, sizeof(hammer_off_t));
 241
 242         hammer_blockmap_free(hmp, elm->leaf.data_offset, elm->leaf.data_len);
 243
 244         kprintf("REBLOCK DATA %016llx -> %016llx\n",
 245                 elm->leaf.data_offset, ndata_offset);
 246         cursor->record->base.data_off = ndata_offset;
 247         elm->leaf.data_offset = ndata_offset;
 248
 249 done:
 250         if (data_buffer)
 251                 hammer_rel_buffer(data_buffer, 0);
 252         return (error);
 253 }
 254
 255 /*
 256  * Reblock a record.  The B-Tree must be adjusted to point to the new record
 257  * and the existing record must be physically destroyed so a FS rebuild
 258  * does not see two versions of the same record.
 259  */
 260 static int
 261 hammer_reblock_record(hammer_mount_t hmp, struct hammer_ioc_reblock *reblock,
 262                       hammer_cursor_t cursor, hammer_btree_elm_t elm)
 263 {
 264         struct hammer_buffer *rec_buffer = NULL;
 265         hammer_off_t nrec_offset;
 266         hammer_record_ondisk_t nrec;
 267         int error;
 268
 269         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_RECORD);
 270         if (error)
 271                 return (error);
 272
 273         nrec = hammer_alloc_record(hmp, &nrec_offset, elm->leaf.base.rec_type,
 274                                   &rec_buffer, 0, NULL, NULL, &error);
 275         if (error)
 276                 goto done;
 277
 278         /*
 279          * Move the record
 280          */
 281         bcopy(cursor->record, nrec, sizeof(*nrec));
 282
 283         hammer_modify_node(cursor->node,
 284                 &elm->leaf.rec_offset, sizeof(hammer_off_t));
 285         hammer_modify_record(cursor->record_buffer,
 286                 &cursor->record->base.base.rec_type,
 287                 sizeof(cursor->record->base.base.rec_type));
 288
 289         hammer_blockmap_free(hmp, elm->leaf.rec_offset, sizeof(*nrec));
 290
 291         kprintf("REBLOCK RECD %016llx -> %016llx\n",
 292                 elm->leaf.rec_offset, nrec_offset);
 293         elm->leaf.rec_offset = nrec_offset;
 294
 295 done:
 296         if (rec_buffer)
 297                 hammer_rel_buffer(rec_buffer, 0);
 298         return (error);
 299 }
 300
 301 /*
 302  * Reblock a B-Tree (leaf) node.  The parent must be adjusted to point to
 303  * the new copy of the leaf node.  elm is a pointer to the parent element
 304  * pointing at cursor.node.
 305  *
 306  * XXX reblock internal nodes too.
 307  */
 308 static int
 309 hammer_reblock_node(hammer_mount_t hmp, struct hammer_ioc_reblock *reblock,
 310                     hammer_cursor_t cursor, hammer_btree_elm_t elm)
 311 {
 312         hammer_node_t onode;
 313         hammer_node_t nnode;
 314         int error;
 315
 316         onode = cursor->node;
 317         nnode = hammer_alloc_btree(hmp, &error);
 318         hammer_lock_ex(&nnode->lock);
 319
 320         if (nnode == NULL)
 321                 return (error);
 322
 323         /*
 324          * Move the node
 325          */
 326         bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
 327
 328         if (elm) {
 329                 /*
 330                  * We are not the root of the B-Tree
 331                  */
 332                 hammer_modify_node(cursor->parent,
 333                                    &elm->internal.subtree_offset,
 334                                    sizeof(elm->internal.subtree_offset));
 335                 elm->internal.subtree_offset = nnode->node_offset;
 336         } else {
 337                 /*
 338                  * We are the root of the B-Tree
 339                  */
 340                 hammer_volume_t volume;
 341
 342                 volume = hammer_get_root_volume(hmp, &error);
 343                 KKASSERT(error == 0);
 344
 345                 hammer_modify_volume(volume, &volume->ondisk->vol0_btree_root,
 346                                      sizeof(hammer_off_t));
 347                 volume->ondisk->vol0_btree_root = nnode->node_offset;
 348                 hammer_rel_volume(volume, 0);
 349         }
 350
 351         onode->flags |= HAMMER_NODE_DELETED;
 352
 353         kprintf("REBLOCK NODE %016llx -> %016llx\n",
 354                 onode->node_offset, nnode->node_offset);
 355
 356         cursor->node = nnode;
 357         hammer_rel_node(onode);
 358
 359         return (error);
 360 }
 361