sys/vfs/hammer/hammer_spike.c

   1 /*
   2  * Copyright (c) 2007 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/Attic/hammer_spike.c,v 1.6 2008/01/11 01:41:34 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 /*
  40  * Load spike info given a cursor.  The cursor must point to the leaf node
  41  * that needs to be spiked.
  42  */
  43 void
  44 hammer_load_spike(hammer_cursor_t cursor, struct hammer_cursor **spikep)
  45 {
  46         hammer_cursor_t spike;
  47
  48         KKASSERT(cursor->node->ondisk->type == HAMMER_BTREE_TYPE_LEAF);
  49         KKASSERT(*spikep == NULL);
  50         *spikep = spike = kmalloc(sizeof(*spike), M_HAMMER, M_WAITOK|M_ZERO);
  51         ++hammer_count_spikes;
  52
  53         spike->parent = cursor->parent;
  54         spike->parent_index = cursor->parent_index;
  55         spike->node = cursor->node;
  56         spike->index = cursor->index;
  57         spike->left_bound = cursor->left_bound;
  58         spike->right_bound = cursor->right_bound;
  59
  60         if (spike->parent) {
  61                 hammer_ref_node(spike->parent);
  62                 hammer_lock_ex(&spike->parent->lock);
  63         }
  64         hammer_ref_node(spike->node);
  65         hammer_lock_ex(&spike->node->lock);
  66         kprintf("LOAD SPIKE %p\n", spike);
  67 }
  68
  69 /*
  70  * Spike code - make room in a cluster by spiking in a new cluster.
  71  *
  72  * The spike structure contains a locked and reference B-Tree leaf node.
  73  * The spike at a minimum must replace the node with a cluster reference
  74  * and then delete the contents of the node.
  75  *
  76  * Various optimizations are desireable, including merging the spike node
  77  * with an adjacent node that has already been spiked, if its cluster is
  78  * not full, or promoting the spike node to the parent cluster of the current
  79  * cluster when it represents the right hand boundary leaf node in the
  80  * cluster (to avoid append chains).
  81  */
  82 int
  83 hammer_spike(struct hammer_cursor **spikep)
  84 {
  85         hammer_cursor_t spike;
  86         struct hammer_cursor ncursor;
  87         hammer_cluster_t ocluster;
  88         hammer_cluster_t ncluster;
  89         hammer_node_t onode;
  90         hammer_record_ondisk_t rec;
  91         int error;
  92
  93         kprintf("hammer_spike: ENOSPC in cluster, spiking\n");
  94         /*Debugger("ENOSPC");*/
  95
  96         /*
  97          * Lock and flush the cluster XXX
  98          */
  99         spike = *spikep;
 100         KKASSERT(spike != NULL);
 101         KKASSERT(spike->parent &&
 102                  spike->parent->cluster == spike->node->cluster);
 103
 104         error = 0;
 105         onode = spike->node;
 106         ocluster = onode->cluster;
 107         hammer_lock_ex(&ocluster->io.lock);
 108
 109         /* XXX */
 110
 111         /*
 112          * Allocate and lock a new cluster, initialize its bounds.
 113          */
 114         ncluster = hammer_alloc_cluster(ocluster->volume->hmp, ocluster,
 115                                         &error);
 116         if (ncluster == NULL)
 117                 goto failed3;
 118         hammer_init_cluster(ncluster, spike->left_bound, spike->right_bound);
 119
 120         /*
 121          * Get a cursor for the new cluster.  Operations will be limited to
 122          * this cluster.
 123          */
 124         error = hammer_init_cursor_cluster(&ncursor, ncluster);
 125         if (error)
 126                 goto failed2;
 127
 128         /*
 129          * Copy the elements in the leaf node.
 130          */
 131         for (spike->index = 0; spike->index < onode->ondisk->count;
 132              ++spike->index) {
 133                 error = hammer_btree_extract(spike, HAMMER_CURSOR_GET_RECORD |
 134                                                     HAMMER_CURSOR_GET_DATA);
 135                 if (error)
 136                         goto failed1;
 137                 kprintf("EXTRACT %04x %016llx %016llx\n",
 138                         spike->record->base.base.rec_type,
 139                         spike->record->base.base.obj_id,
 140                         spike->record->base.base.key);
 141                 error = hammer_write_record(&ncursor, spike->record,
 142                                             spike->data, spike->flags);
 143                 if (error == ENOSPC) {
 144                         kprintf("impossible ENOSPC error on spike\n");
 145                         error = EIO;
 146                 }
 147                 if (error)
 148                         goto failed1;
 149         }
 150
 151         /*
 152          * Success!  Replace the parent reference to the leaf node with a
 153          * parent reference to the new cluster and fixup the new cluster's
 154          * parent reference.  This completes the spike operation.
 155          */
 156         {
 157                 hammer_node_ondisk_t ondisk;
 158                 hammer_btree_elm_t elm;
 159
 160                 hammer_modify_node(spike->parent);
 161                 ondisk = spike->parent->ondisk;
 162                 elm = &ondisk->elms[spike->parent_index];
 163                 elm->internal.subtree_type = HAMMER_BTREE_TYPE_CLUSTER;
 164                 elm->internal.rec_offset = -1; /* XXX */
 165                 elm->internal.subtree_clu_no = ncluster->clu_no;
 166                 elm->internal.subtree_vol_no = ncluster->volume->vol_no;
 167                 elm->internal.subtree_count = onode->ondisk->count; /*XXX*/
 168                 onode->flags |= HAMMER_NODE_MODIFIED;
 169                 hammer_flush_node(onode);
 170         }
 171         {
 172                 hammer_cluster_ondisk_t ondisk;
 173
 174                 hammer_modify_cluster(ncluster);
 175                 ondisk = ncluster->ondisk;
 176                 ondisk->clu_btree_parent_vol_no = ocluster->volume->vol_no;
 177                 ondisk->clu_btree_parent_clu_no = ocluster->clu_no;
 178                 ondisk->clu_btree_parent_offset = spike->parent->node_offset;
 179                 ondisk->clu_btree_parent_clu_gen = ocluster->ondisk->clu_gen;
 180         }
 181
 182         /*
 183          * Delete the records and data associated with the old leaf node,
 184          * then free the old leaf node (nothing references it any more).
 185          */
 186         for (spike->index = 0; spike->index < onode->ondisk->count;
 187              ++spike->index) {
 188                 hammer_btree_elm_t elm;
 189                 int32_t roff;
 190
 191                 elm = &onode->ondisk->elms[spike->index];
 192                 KKASSERT(elm->leaf.rec_offset > 0);
 193                 hammer_free_record(ocluster, elm->leaf.rec_offset);
 194                 if (elm->leaf.data_offset) {
 195                         roff = elm->leaf.data_offset - elm->leaf.rec_offset;
 196                         if (roff < 0 || roff >= HAMMER_RECORD_SIZE) {
 197                                 hammer_free_data(ocluster,
 198                                                  elm->leaf.data_offset,
 199                                                  elm->leaf.data_len);
 200                         }
 201                 }
 202         }
 203         onode->flags |= HAMMER_NODE_DELETED;
 204
 205         /*
 206          * Add a record representing the spike using space freed up by the
 207          * above deletions.
 208          */
 209         rec = hammer_alloc_record(ocluster, &error, &spike->record_buffer);
 210         KKASSERT(error == 0);
 211         rec->spike.base.base.rec_type = HAMMER_RECTYPE_CLUSTER;
 212         rec->spike.clu_no = ncluster->clu_no;
 213         rec->spike.vol_no = ncluster->volume->vol_no;
 214         rec->spike.clu_id = 0;
 215
 216         /*
 217          * XXX I/O dependancy - new cluster must be flushed before current
 218          * cluster can be flushed.
 219          */
 220         /*Debugger("COPY COMPLETE");*/
 221         hammer_done_cursor(&ncursor);
 222         goto success;
 223
 224         /*
 225          * Cleanup
 226          */
 227 failed1:
 228         hammer_done_cursor(&ncursor);
 229 failed2:
 230         hammer_free_cluster(ncluster);
 231 success:
 232         hammer_unlock(&ncluster->io.lock);
 233         hammer_rel_cluster(ncluster, 0);
 234 failed3:
 235         kprintf("UNLOAD SPIKE %p %d\n", spike, error);
 236         hammer_unlock(&ocluster->io.lock);
 237         hammer_done_cursor(spike);
 238         --hammer_count_spikes;
 239         kfree(spike, M_HAMMER);
 240         *spikep = NULL;
 241         return (error);
 242 }
 243