rf_dagffrd.c

RAIDFrame是个非常好的磁盘阵列RAID仿真工具

    (RF_DagNode_t *), allocList);
  i = 0;
  diskNodes   = &nodes[i]; i += n;
  blockNode   = &nodes[i]; i += 1;
  commitNode   = &nodes[i]; i += 1;
  termNode    = &nodes[i];  i += 1;
  RF_ASSERT(i == totalNumNodes);

  /* initialize nodes */
  switch (type) {
    case RF_IO_TYPE_READ:
      rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc,
        NULL, n, 0, 0, 0, dag_h, "Nil", allocList);
      rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc,
        NULL, 1, n, 0, 0, dag_h, "Cmt", allocList);
      rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc,
        NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
      break;
    case RF_IO_TYPE_WRITE:
      rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc,
        NULL, 1, 0, 0, 0, dag_h, "Nil", allocList);
      rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc,
        NULL, n, 1, 0, 0, dag_h, "Cmt", allocList);
      rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc,
        NULL, 0, n, 0, 0, dag_h, "Trm", allocList);
      break;
    default:
      RF_PANIC();
  }

  for (i = 0; i < n; i++) {
    RF_ASSERT(pda != NULL);
    rf_InitNode(&diskNodes[i], rf_wait, RF_FALSE, doFunc, undoFunc, rf_GenericWakeupFunc,
      1, 1, 4, 0, dag_h, name, allocList);
    diskNodes[i].params[0].p  = pda;
    diskNodes[i].params[1].p  = pda->bufPtr;
    /* parity stripe id is not necessary */
    diskNodes[i].params[2].v  = 0;
    diskNodes[i].params[3].v  = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, 0);
    pda = pda->next;
  }

  /*
   * Connect nodes.
   */

  /* connect hdr to block node */
  RF_ASSERT(blockNode->numAntecedents == 0);
  dag_h->succedents[0] = blockNode;

  if (type == RF_IO_TYPE_READ) {
    /* connecting a nonredundant read DAG */
    RF_ASSERT(blockNode->numSuccedents == n);
    RF_ASSERT(commitNode->numAntecedents == n);
    for (i=0; i < n; i++) {
      /* connect block node to each read node */
      RF_ASSERT(diskNodes[i].numAntecedents == 1);
      blockNode->succedents[i] = &diskNodes[i];
      diskNodes[i].antecedents[0] = blockNode;
      diskNodes[i].antType[0] = rf_control;

      /* connect each read node to the commit node */
      RF_ASSERT(diskNodes[i].numSuccedents == 1);
      diskNodes[i].succedents[0] = commitNode;
      commitNode->antecedents[i] = &diskNodes[i];
      commitNode->antType[i] = rf_control;
    }
    /* connect the commit node to the term node */
    RF_ASSERT(commitNode->numSuccedents == 1);
    RF_ASSERT(termNode->numAntecedents == 1);
    RF_ASSERT(termNode->numSuccedents == 0);
    commitNode->succedents[0] = termNode;
    termNode->antecedents[0] = commitNode;
    termNode->antType[0] = rf_control;
  }
  else {
    /* connecting a nonredundant write DAG */
    /* connect the block node to the commit node */
    RF_ASSERT(blockNode->numSuccedents == 1);
    RF_ASSERT(commitNode->numAntecedents == 1);
    blockNode->succedents[0] = commitNode;
    commitNode->antecedents[0] = blockNode;
    commitNode->antType[0] = rf_control;

    RF_ASSERT(commitNode->numSuccedents == n);
    RF_ASSERT(termNode->numAntecedents == n);
    RF_ASSERT(termNode->numSuccedents == 0);
    for (i=0; i < n; i++) {
      /* connect the commit node to each write node */
      RF_ASSERT(diskNodes[i].numAntecedents == 1);
      commitNode->succedents[i] = &diskNodes[i];
      diskNodes[i].antecedents[0] = commitNode;
      diskNodes[i].antType[0] = rf_control;

      /* connect each write node to the term node */
      RF_ASSERT(diskNodes[i].numSuccedents == 1);
      diskNodes[i].succedents[0] = termNode;
      termNode->antecedents[i] = &diskNodes[i];
      termNode->antType[i] = rf_control;
    }
  }
}

/******************************************************************************
 * Create a fault-free read DAG for RAID level 1
 *
 * Hdr -> Nil -> Rmir -> Cmt -> Trm
 *
 * The "Rmir" node schedules a read from the disk in the mirror pair with the
 * shortest disk queue.  the proper queue is selected at Rmir execution.  this
 * deferred mapping is unlike other archs in RAIDframe which generally fix
 * mapping at DAG creation time.
 *
 * Parameters:  raidPtr   - description of the physical array
 *              asmap     - logical & physical addresses for this access
 *              bp        - buffer ptr (for holding read data)
 *              flags     - general flags (e.g. disk locking) 
 *              allocList - list of memory allocated in DAG creation
 *****************************************************************************/

static void CreateMirrorReadDAG(
  RF_Raid_t             *raidPtr,
  RF_AccessStripeMap_t  *asmap,
  RF_DagHeader_t        *dag_h,
  void                  *bp,
  RF_RaidAccessFlags_t   flags,
  RF_AllocListElem_t    *allocList,
  int                   (*readfunc)(RF_DagNode_t *node))
{
  RF_DagNode_t *readNodes, *nodes, *blockNode, *commitNode, *termNode;
  RF_PhysDiskAddr_t *data_pda = asmap->physInfo;
  RF_PhysDiskAddr_t *parity_pda = asmap->parityInfo;
  int i, n, totalNumNodes;

  n = asmap->numStripeUnitsAccessed;
  dag_h->creator = "RaidOneReadDAG";
  if (rf_dagDebug) {
    printf("[Creating RAID level 1 read DAG]\n");
  }

  /*
   * This dag can not commit until the commit node is reached
   * errors prior to the commit point imply the dag has failed.
   */
  dag_h->numCommitNodes = 1;
  dag_h->numCommits = 0;
  dag_h->numSuccedents = 1;

  /*
   * Node count:
   * n data reads
   * 1 block node
   * 1 commit node
   * 1 terminator node
   */
  RF_ASSERT(n > 0);
  totalNumNodes = n + 3;
  RF_CallocAndAdd(nodes, totalNumNodes, sizeof(RF_DagNode_t),
    (RF_DagNode_t *), allocList);
  i = 0;
  readNodes   = &nodes[i]; i += n;
  blockNode   = &nodes[i]; i += 1;
  commitNode = &nodes[i]; i += 1;
  termNode    = &nodes[i]; i += 1;
  RF_ASSERT(i == totalNumNodes);

  /* initialize nodes */
  rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
    rf_NullNodeUndoFunc, NULL, n, 0, 0, 0, dag_h, "Nil", allocList);
  rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
    rf_NullNodeUndoFunc, NULL, 1, n, 0, 0, dag_h, "Cmt", allocList);
  rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
    rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);

  for (i = 0; i < n; i++) {
    RF_ASSERT(data_pda != NULL);
    RF_ASSERT(parity_pda != NULL);
    rf_InitNode(&readNodes[i], rf_wait, RF_FALSE, readfunc,
      rf_DiskReadMirrorUndoFunc, rf_GenericWakeupFunc, 1, 1, 5, 0, dag_h,
      "Rmir", allocList);
    readNodes[i].params[0].p = data_pda;
    readNodes[i].params[1].p = data_pda->bufPtr;
    /* parity stripe id is not necessary */
    readNodes[i].params[2].p = 0;
    readNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, 0);
    readNodes[i].params[4].p = parity_pda;
    data_pda = data_pda->next;
    parity_pda = parity_pda->next;
  }

  /*
   * Connect nodes
   */

  /* connect hdr to block node */
  RF_ASSERT(blockNode->numAntecedents == 0);
  dag_h->succedents[0] = blockNode;

  /* connect block node to read nodes */
  RF_ASSERT(blockNode->numSuccedents == n);
  for (i=0; i < n; i++) {
    RF_ASSERT(readNodes[i].numAntecedents == 1);
    blockNode->succedents[i] = &readNodes[i];
    readNodes[i].antecedents[0] = blockNode;
    readNodes[i].antType[0] = rf_control;
  }

  /* connect read nodes to commit node */
  RF_ASSERT(commitNode->numAntecedents == n);
  for (i=0; i < n; i++) {
    RF_ASSERT(readNodes[i].numSuccedents == 1);
    readNodes[i].succedents[0] = commitNode;
    commitNode->antecedents[i] = &readNodes[i];
    commitNode->antType[i] = rf_control;
  }

  /* connect commit node to term node */
  RF_ASSERT(commitNode->numSuccedents == 1);
  RF_ASSERT(termNode->numAntecedents == 1);
  RF_ASSERT(termNode->numSuccedents == 0);
  commitNode->succedents[0] = termNode;
  termNode->antecedents[0] = commitNode;
  termNode->antType[0] = rf_control;
}

void rf_CreateMirrorIdleReadDAG(
  RF_Raid_t             *raidPtr,
  RF_AccessStripeMap_t  *asmap,
  RF_DagHeader_t        *dag_h,
  void                  *bp,
  RF_RaidAccessFlags_t   flags,
  RF_AllocListElem_t    *allocList)
{
  CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList,
    rf_DiskReadMirrorIdleFunc);
}

void rf_CreateMirrorPartitionReadDAG(
  RF_Raid_t             *raidPtr,
  RF_AccessStripeMap_t  *asmap,
  RF_DagHeader_t        *dag_h,
  void                  *bp,
  RF_RaidAccessFlags_t   flags,
  RF_AllocListElem_t    *allocList)
{
  CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList,
    rf_DiskReadMirrorPartitionFunc);
}