BUG#27370: Potential inconsistent blob reads for ReadCommitted reads.

The old blob implementation had code that attempted to upgrade the lock mode for
LM_CommittedRead operations, but it did not work properly as it did not recompute
the operation flags.

As a consequence, reading a blob with LM_CommittedRead could return inconsistent
data, with different part of the read data being from different commits done by
other transactions.

The fix is to correctly recompute all necessary flags when upgrading lock mode.


ndb/include/kernel/signaldata/ScanTab.hpp:
  Remove assumption in setXXX() methods that old value is zero, needed to allow blob
  code to upgrade lock mode.
  Fix spelling and commments.
ndb/include/ndbapi/NdbOperation.hpp:
  Add method to change lock mode, to allow blob code to upgrade lock mode.
ndb/include/ndbapi/NdbScanOperation.hpp:
  Add method to change lock mode, to allow blob code to upgrade lock mode.
ndb/src/ndbapi/NdbBlob.cpp:
  Fix upgrading lock mode (old code had no effect).
ndb/src/ndbapi/NdbOperationDefine.cpp:
  Add method to change lock mode, to allow blob code to upgrade lock mode.
ndb/src/ndbapi/NdbScanOperation.cpp:
  Add method to change lock mode, to allow blob code to upgrade lock mode.
ndb/test/ndbapi/testBlobs.cpp:
  Add testcase.
ndb/test/run-test/daily-basic-tests.txt:
  Enable bug tests for auto test.

mysql-test/r/bdb_notembedded.result

+set autocommit=1;
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+drop table bug16206;
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int) engine=         bdb
+f	n	Query	1	n	use `test`; insert into bug16206 values(0)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; BEGIN
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+f	n	Query	1	n	use `test`; COMMIT
+f	n	Query	1	n	use `test`; insert into bug16206 values(3)
+drop table bug16206;
+set autocommit=0;
+End of 5.0 tests

mysql-test/t/bdb_notembedded.test

+-- source include/not_embedded.inc
+-- source include/have_bdb.inc
+
+#
+# Bug #16206: Superfluous COMMIT event in binlog when updating BDB in autocommit mode
+#
+set autocommit=1;
+
+let $VERSION=`select version()`;
+
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+set autocommit=0;
+
+
+--echo End of 5.0 tests

ndb/include/kernel/signaldata/ScanTab.hpp

@@ -113,15 +113,15 @@ private:
  z = Descending (TUX)      - 1  Bit 14
  x = Range Scan (TUX)      - 1  Bit 15
  b = Scan batch            - 10 Bit 16-25 (max 1023)
- d = Distribution key flag
+ d = Distribution key flag - 1  Bit 26
 
            1111111111222222222233
  01234567890123456789012345678901
- ppppppppl hcktzxbbbbbbbbbb
+ ppppppppl hcktzxbbbbbbbbbbd
 */
 
-#define PARALLELL_SHIFT     (0)
-#define PARALLELL_MASK      (255)
+#define PARALLEL_SHIFT     (0)
+#define PARALLEL_MASK      (255)
 
 #define LOCK_MODE_SHIFT     (8)
 #define LOCK_MODE_MASK      (1)
@@ -148,11 +148,12 @@ private:
 #define SCAN_BATCH_MASK  (1023)
 
 #define SCAN_DISTR_KEY_SHIFT (26)
+#define SCAN_DISTR_KEY_MASK (1)
 
 inline
 Uint8
 ScanTabReq::getParallelism(const UintR & requestInfo){
-  return (Uint8)((requestInfo >> PARALLELL_SHIFT) & PARALLELL_MASK);
+  return (Uint8)((requestInfo >> PARALLEL_SHIFT) & PARALLEL_MASK);
 }
 
 inline
@@ -206,58 +207,65 @@ ScanTabReq::clearRequestInfo(UintR & requestInfo){
 inline
 void 
 ScanTabReq::setParallelism(UintR & requestInfo, Uint32 type){
-  ASSERT_MAX(type, PARALLELL_MASK, "ScanTabReq::setParallellism");
-  requestInfo |= (type << PARALLELL_SHIFT);
+  ASSERT_MAX(type, PARALLEL_MASK, "ScanTabReq::setParallelism");
+  requestInfo= (requestInfo & ~(PARALLEL_MASK << PARALLEL_SHIFT)) |
+               ((type & PARALLEL_MASK) << PARALLEL_SHIFT);
 }
 
 inline
 void 
 ScanTabReq::setLockMode(UintR & requestInfo, Uint32 mode){
   ASSERT_MAX(mode, LOCK_MODE_MASK,  "ScanTabReq::setLockMode");
-  requestInfo |= (mode << LOCK_MODE_SHIFT);
+  requestInfo= (requestInfo & ~(LOCK_MODE_MASK << LOCK_MODE_SHIFT)) |
+               ((mode & LOCK_MODE_MASK) << LOCK_MODE_SHIFT);
 }
 
 inline
 void 
 ScanTabReq::setHoldLockFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setHoldLockFlag");
-  requestInfo |= (flag << HOLD_LOCK_SHIFT);
+  requestInfo= (requestInfo & ~(HOLD_LOCK_MASK << HOLD_LOCK_SHIFT)) |
+               ((flag & HOLD_LOCK_MASK) << HOLD_LOCK_SHIFT);
 }
 
 inline
 void 
 ScanTabReq::setReadCommittedFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setReadCommittedFlag");
-  requestInfo |= (flag << READ_COMMITTED_SHIFT);
+  requestInfo= (requestInfo & ~(READ_COMMITTED_MASK << READ_COMMITTED_SHIFT)) |
+               ((flag & READ_COMMITTED_MASK) << READ_COMMITTED_SHIFT);
 }
 
 inline
 void 
 ScanTabReq::setRangeScanFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setRangeScanFlag");
-  requestInfo |= (flag << RANGE_SCAN_SHIFT);
+  requestInfo= (requestInfo & ~(RANGE_SCAN_MASK << RANGE_SCAN_SHIFT)) |
+               ((flag & RANGE_SCAN_MASK) << RANGE_SCAN_SHIFT);
 }
 
 inline
 void 
 ScanTabReq::setDescendingFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setDescendingFlag");
-  requestInfo |= (flag << DESCENDING_SHIFT);
+  requestInfo= (requestInfo & ~(DESCENDING_MASK << DESCENDING_SHIFT)) |
+               ((flag & DESCENDING_MASK) << DESCENDING_SHIFT);
 }
 
 inline
 void 
 ScanTabReq::setTupScanFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setTupScanFlag");
-  requestInfo |= (flag << TUP_SCAN_SHIFT);
+  requestInfo= (requestInfo & ~(TUP_SCAN_MASK << TUP_SCAN_SHIFT)) |
+               ((flag & TUP_SCAN_MASK) << TUP_SCAN_SHIFT);
 }
 
 inline
 void
 ScanTabReq::setScanBatch(Uint32 & requestInfo, Uint32 flag){
   ASSERT_MAX(flag, SCAN_BATCH_MASK,  "ScanTabReq::setScanBatch");
-  requestInfo &= ~(SCAN_BATCH_MASK << SCAN_BATCH_SHIFT);
-  requestInfo |= (flag << SCAN_BATCH_SHIFT);
+  requestInfo= (requestInfo & ~(SCAN_BATCH_MASK << SCAN_BATCH_SHIFT)) |
+               ((flag & SCAN_BATCH_MASK) << SCAN_BATCH_SHIFT);
 }
 
 inline
@@ -270,7 +278,8 @@ inline
 void 
 ScanTabReq::setKeyinfoFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setKeyinfoFlag");
-  requestInfo |= (flag << KEYINFO_SHIFT);
+  requestInfo= (requestInfo & ~(KEYINFO_MASK << KEYINFO_SHIFT)) |
+               ((flag & KEYINFO_MASK) << KEYINFO_SHIFT);
 }
 
 inline
@@ -283,7 +292,8 @@ inline
 void 
 ScanTabReq::setDistributionKeyFlag(UintR & requestInfo, Uint32 flag){
   ASSERT_BOOL(flag, "ScanTabReq::setKeyinfoFlag");
-  requestInfo |= (flag << SCAN_DISTR_KEY_SHIFT);
+  requestInfo= (requestInfo & ~(SCAN_DISTR_KEY_MASK << SCAN_DISTR_KEY_SHIFT)) |
+               ((flag & SCAN_DISTR_KEY_MASK) << SCAN_DISTR_KEY_SHIFT);
 }
 
 /**

ndb/include/ndbapi/NdbOperation.hpp

@@ -908,6 +908,8 @@ protected:
   // get table or index key from prepared signals
   int getKeyFromTCREQ(Uint32* data, unsigned size);
 
+  virtual void setReadLockMode(LockMode lockMode);
+
 /******************************************************************************
  * These are the private variables that are defined in the operation objects.
  *****************************************************************************/

ndb/include/ndbapi/NdbScanOperation.hpp

@@ -212,6 +212,7 @@ protected:
   int prepareSend(Uint32  TC_ConnectPtr, Uint64  TransactionId);
   int doSend(int ProcessorId);
   void checkForceSend(bool forceSend);
+  virtual void setReadLockMode(LockMode lockMode);
 
   virtual void setErrorCode(int aErrorCode);
   virtual void setErrorCodeAbort(int aErrorCode);

ndb/src/ndbapi/NdbBlob.cpp

@@ -1157,7 +1157,7 @@ NdbBlob::atPrepare(NdbTransaction* aCon, NdbOperation* anOp, const NdbColumnImpl
     if (isReadOp()) {
       // upgrade lock mode
       if (theNdbOp->theLockMode == NdbOperation::LM_CommittedRead)
-        theNdbOp->theLockMode = NdbOperation::LM_Read;
+        theNdbOp->setReadLockMode(NdbOperation::LM_Read);
       // add read of head+inline in this op
       if (getHeadInlineValue(theNdbOp) == -1)
         DBUG_RETURN(-1);
@@ -1178,7 +1178,7 @@ NdbBlob::atPrepare(NdbTransaction* aCon, NdbOperation* anOp, const NdbColumnImpl
   if (isScanOp()) {
     // upgrade lock mode
     if (theNdbOp->theLockMode == NdbOperation::LM_CommittedRead)
-      theNdbOp->theLockMode = NdbOperation::LM_Read;
+      theNdbOp->setReadLockMode(NdbOperation::LM_Read);
     // add read of head+inline in this op
     if (getHeadInlineValue(theNdbOp) == -1)
       DBUG_RETURN(-1);

ndb/src/ndbapi/NdbOperationDefine.cpp

@@ -322,6 +322,36 @@ NdbOperation::interpretedDeleteTuple()
   }//if
 }//NdbOperation::interpretedDeleteTuple()
 
+void
+NdbOperation::setReadLockMode(LockMode lockMode)
+{
+  /* We only support changing lock mode for read operations at this time. */
+  assert(theOperationType == ReadRequest || theOperationType == ReadExclusive);
+  switch (lockMode)
+  {
+    case LM_CommittedRead:
+      theOperationType= ReadRequest;
+      theSimpleIndicator= 1;
+      theDirtyIndicator= 1;
+      break;
+    case LM_Read:
+      theNdbCon->theSimpleState= 0;
+      theOperationType= ReadRequest;
+      theSimpleIndicator= 0;
+      theDirtyIndicator= 0;
+      break;
+    case LM_Exclusive:
+      theNdbCon->theSimpleState= 0;
+      theOperationType= ReadExclusive;
+      theSimpleIndicator= 0;
+      theDirtyIndicator= 0;
+      break;
+    default:
+      /* Not supported / invalid. */
+      assert(false);
+  }
+  theLockMode= lockMode;
+}
 
 
 /******************************************************************************

ndb/src/ndbapi/NdbScanOperation.cpp

@@ -136,31 +136,6 @@ NdbScanOperation::readTuples(NdbScanOperation::LockMode lm,
   }
 
   theNdbCon->theScanningOp = this;
-  theLockMode = lm;
-
-  bool lockExcl, lockHoldMode, readCommitted;
-  switch(lm){
-  case NdbScanOperation::LM_Read:
-    lockExcl = false;
-    lockHoldMode = true;
-    readCommitted = false;
-    break;
-  case NdbScanOperation::LM_Exclusive:
-    lockExcl = true;
-    lockHoldMode = true;
-    readCommitted = false;
-    break;
-  case NdbScanOperation::LM_CommittedRead:
-    lockExcl = false;
-    lockHoldMode = false;
-    readCommitted = true;
-    break;
-  default:
-    setErrorCode(4003);
-    return -1;
-  }
-
-  m_keyInfo = ((scan_flags & SF_KeyInfo) || lockExcl) ? 1 : 0;
 
   bool rangeScan = false;
   if (m_accessTable->m_indexType == NdbDictionary::Index::OrderedIndex)
@@ -210,13 +185,13 @@ NdbScanOperation::readTuples(NdbScanOperation::LockMode lm,
   Uint32 reqInfo = 0;
   ScanTabReq::setParallelism(reqInfo, parallel);
   ScanTabReq::setScanBatch(reqInfo, 0);
-  ScanTabReq::setLockMode(reqInfo, lockExcl);
-  ScanTabReq::setHoldLockFlag(reqInfo, lockHoldMode);
-  ScanTabReq::setReadCommittedFlag(reqInfo, readCommitted);
   ScanTabReq::setRangeScanFlag(reqInfo, rangeScan);
   ScanTabReq::setTupScanFlag(reqInfo, tupScan);
   req->requestInfo = reqInfo;
 
+  m_keyInfo = (scan_flags & SF_KeyInfo) ? 1 : 0;
+  setReadLockMode(lm);
+
   Uint64 transId = theNdbCon->getTransactionId();
   req->transId1 = (Uint32) transId;
   req->transId2 = (Uint32) (transId >> 32);
@@ -236,6 +211,41 @@ NdbScanOperation::readTuples(NdbScanOperation::LockMode lm,
   return 0;
 }
 
+void
+NdbScanOperation::setReadLockMode(LockMode lockMode)
+{
+  bool lockExcl, lockHoldMode, readCommitted;
+  switch (lockMode)
+  {
+    case LM_CommittedRead:
+      lockExcl= false;
+      lockHoldMode= false;
+      readCommitted= true;
+      break;
+    case LM_Read:
+      lockExcl= false;
+      lockHoldMode= true;
+      readCommitted= false;
+      break;
+    case LM_Exclusive:
+      lockExcl= true;
+      lockHoldMode= true;
+      readCommitted= false;
+      m_keyInfo= 1;
+      break;
+    default:
+      /* Not supported / invalid. */
+      assert(false);
+  }
+  theLockMode= lockMode;
+  ScanTabReq *req= CAST_PTR(ScanTabReq, theSCAN_TABREQ->getDataPtrSend());
+  Uint32 reqInfo= req->requestInfo;
+  ScanTabReq::setLockMode(reqInfo, lockExcl);
+  ScanTabReq::setHoldLockFlag(reqInfo, lockHoldMode);
+  ScanTabReq::setReadCommittedFlag(reqInfo, readCommitted);
+  req->requestInfo= reqInfo;
+}
+
 int
 NdbScanOperation::fix_receivers(Uint32 parallel){
   assert(parallel > 0);

ndb/test/ndbapi/testBlobs.cpp

@@ -139,6 +139,7 @@ printusage()
     << "bug tests (no blob test)" << endl
     << "  -bug 4088   ndb api hang with mixed ops on index table" << endl
     << "  -bug 27018  middle partial part write clobbers rest of part" << endl
+    << "  -bug 27370  Potential inconsistent blob reads for ReadCommitted reads" << endl
     << "  -bug nnnn   delete + write gives 626" << endl
     << "  -bug nnnn   acc crash on delete and long key" << endl
     ;
@@ -1857,6 +1858,203 @@ bugtest_27018()
   return 0;
 }
 
+
+struct bug27370_data {
+  Ndb *m_ndb;
+  char m_current_write_value;
+  char *m_writebuf;
+  Uint32 m_blob1_size;
+  Uint32 m_pk1;
+  char m_pk2[g_max_pk2len + 1];
+  bool m_thread_stop;
+};
+
+void *bugtest_27370_thread(void *arg)
+{
+  bug27370_data *data= (bug27370_data *)arg;
+
+  while (!data->m_thread_stop)
+  {
+    memset(data->m_writebuf, data->m_current_write_value, data->m_blob1_size);
+    data->m_current_write_value++;
+
+    NdbConnection *con;
+    if ((con= data->m_ndb->startTransaction()) == 0)
+      return (void *)"Failed to create transaction";
+    NdbOperation *opr;
+    if ((opr= con->getNdbOperation(g_opt.m_tname)) == 0)
+      return (void *)"Failed to create operation";
+    if (opr->writeTuple() != 0)
+      return (void *)"writeTuple() failed";
+    if (opr->equal("PK1", data->m_pk1) != 0)
+      return (void *)"equal(PK1) failed";
+    if (g_opt.m_pk2len != 0)
+      if (opr->equal("PK2", data->m_pk2) != 0)
+        return (void *)"equal(PK2) failed";
+    NdbBlob *bh;
+    if ((bh= opr->getBlobHandle("BL1")) == 0)
+      return (void *)"getBlobHandle() failed";
+    if (bh->setValue(data->m_writebuf, data->m_blob1_size) != 0)
+      return (void *)"setValue() failed";
+    if (con->execute(Commit, AbortOnError, 1) != 0)
+      return (void *)"execute() failed";
+    data->m_ndb->closeTransaction(con);
+  }
+
+  return NULL;                                  // Success
+}
+
+static int
+bugtest_27370()
+{
+  DBG("bug test 27370 - Potential inconsistent blob reads for ReadCommitted reads");
+
+  bug27370_data data;
+
+  data.m_ndb= new Ndb(g_ncc, "TEST_DB");
+  CHK(data.m_ndb->init(20) == 0);
+  CHK(data.m_ndb->waitUntilReady() == 0);
+
+  data.m_current_write_value= 0;
+  data.m_blob1_size= g_opt.m_blob1.m_inline + 10 * g_opt.m_blob1.m_partsize;
+  CHK((data.m_writebuf= new char [data.m_blob1_size]) != 0);
+  data.m_pk1= 27370;
+  memset(data.m_pk2, 'x', g_max_pk2len);
+  data.m_pk2[g_max_pk2len]= '\0';
+  data.m_thread_stop= false;
+
+  memset(data.m_writebuf, data.m_current_write_value, data.m_blob1_size);
+  data.m_current_write_value++;
+
+  CHK((g_con= g_ndb->startTransaction()) != 0);
+  CHK((g_opr= g_con->getNdbOperation(g_opt.m_tname)) != 0);
+  CHK(g_opr->writeTuple() == 0);
+  CHK(g_opr->equal("PK1", data.m_pk1) == 0);
+  if (g_opt.m_pk2len != 0)
+    CHK(g_opr->equal("PK2", data.m_pk2) == 0);
+  CHK((g_bh1= g_opr->getBlobHandle("BL1")) != 0);
+  CHK(g_bh1->setValue(data.m_writebuf, data.m_blob1_size) == 0);
+  CHK(g_con->execute(Commit) == 0);
+  g_ndb->closeTransaction(g_con);
+  g_con= NULL;
+
+  pthread_t thread_handle;
+  CHK(pthread_create(&thread_handle, NULL, bugtest_27370_thread, &data) == 0);
+
+  DBG("bug test 27370 - PK blob reads");
+  Uint32 seen_updates= 0;
+  while (seen_updates < 50)
+  {
+    CHK((g_con= g_ndb->startTransaction()) != 0);
+    CHK((g_opr= g_con->getNdbOperation(g_opt.m_tname)) != 0);
+    CHK(g_opr->readTuple(NdbOperation::LM_CommittedRead) == 0);
+    CHK(g_opr->equal("PK1", data.m_pk1) == 0);
+    if (g_opt.m_pk2len != 0)
+      CHK(g_opr->equal("PK2", data.m_pk2) == 0);
+    CHK((g_bh1= g_opr->getBlobHandle("BL1")) != 0);
+    CHK(g_con->execute(NoCommit, AbortOnError, 1) == 0);
+
+    const Uint32 loop_max= 10;
+    char read_char;
+    char original_read_char= 0;
+    Uint32 readloop;
+    for (readloop= 0;; readloop++)
+    {
+      if (readloop > 0)
+      {
+        if (readloop > 1)
+        {
+          /* Compare against first read. */
+          CHK(read_char == original_read_char);
+        }
+        else
+        {
+          /*
+            We count the number of times we see the other thread had the
+            chance to update, so that we can be sure it had the opportunity
+            to run a reasonable number of times before we stop.
+          */
+          if (original_read_char != read_char)
+            seen_updates++;
+          original_read_char= read_char;
+        }
+      }
+      if (readloop > loop_max)
+        break;
+      Uint32 readSize= 1;
+      CHK(g_bh1->setPos(urandom(data.m_blob1_size)) == 0);
+      CHK(g_bh1->readData(&read_char, readSize) == 0);
+      CHK(readSize == 1);
+      ExecType commitType= readloop == loop_max ? Commit : NoCommit;
+      CHK(g_con->execute(commitType, AbortOnError, 1) == 0);
+    }
+    g_ndb->closeTransaction(g_con);
+    g_con= NULL;
+  }
+
+  DBG("bug test 27370 - table scan blob reads");
+  seen_updates= 0;
+  while (seen_updates < 50)
+  {
+    CHK((g_con= g_ndb->startTransaction()) != 0);
+    CHK((g_ops= g_con->getNdbScanOperation(g_opt.m_tname)) != 0);
+    CHK(g_ops->readTuples(NdbOperation::LM_CommittedRead) == 0);
+    CHK((g_bh1= g_ops->getBlobHandle("BL1")) != 0);
+    CHK(g_con->execute(NoCommit, AbortOnError, 1) == 0);
+    CHK(g_ops->nextResult(true) == 0);
+
+    const Uint32 loop_max= 10;
+    char read_char;
+    char original_read_char= 0;
+    Uint32 readloop;
+    for (readloop= 0;; readloop++)
+    {
+      if (readloop > 0)
+      {
+        if (readloop > 1)
+        {
+          /* Compare against first read. */
+          CHK(read_char == original_read_char);
+        }
+        else
+        {
+          /*
+            We count the number of times we see the other thread had the
+            chance to update, so that we can be sure it had the opportunity
+            to run a reasonable number of times before we stop.
+          */
+          if (original_read_char != read_char)
+            seen_updates++;
+          original_read_char= read_char;
+        }
+      }
+      if (readloop > loop_max)
+        break;
+      Uint32 readSize= 1;
+      CHK(g_bh1->setPos(urandom(data.m_blob1_size)) == 0);
+      CHK(g_bh1->readData(&read_char, readSize) == 0);
+      CHK(readSize == 1);
+      CHK(g_con->execute(NoCommit, AbortOnError, 1) == 0);
+    }
+
+    CHK(g_ops->nextResult(true) == 1);
+    g_ndb->closeTransaction(g_con);
+    g_con= NULL;
+  }
+
+  data.m_thread_stop= true;
+  void *thread_return;
+  CHK(pthread_join(thread_handle, &thread_return) == 0);
+  DBG("bug 27370 - thread return status: " <<
+      (thread_return ? (char *)thread_return : "<null>"));
+  CHK(thread_return == 0);
+
+  g_con= NULL;
+  g_opr= NULL;
+  g_bh1= NULL;
+  return 0;
+}
+
 static int
 bugtest_2222()
 {
@@ -1874,7 +2072,8 @@ static struct {
   int (*m_test)();
 } g_bugtest[] = {
   { 4088, bugtest_4088 },
-  { 27018, bugtest_27018 }
+  { 27018, bugtest_27018 },
+  { 27370, bugtest_27370 }
 };
 
 NDB_COMMAND(testOdbcDriver, "testBlobs", "testBlobs", "testBlobs", 65535)

ndb/test/run-test/daily-basic-tests.txt

@@ -645,6 +645,14 @@ max-time: 600
 cmd: testBlobs
 args:
 
+max-time: 600
+cmd: testBlobs
+args: -bug 27018
+
+max-time: 600
+cmd: testBlobs
+args: -bug 27370
+
 max-time: 5000
 cmd: testOIBasic
 args: -case abcdefz