HPCC-12087 Ensure cached files released by implicit transaction

A few fileservice operations on superfiles, effectively leaked
the locks to subfiles, which in turn could cause deadlock when
subsequent super ops. tried to manipulate those subfiles.

This fix, adds an implicit transaction block around the effected
operations, to ensure that on exit the cache entries are cleared.
The added implicit transaction will have no effect, if these
methods are called from a user transaction.

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>

plugins/fileservices/fileservices.cpp

@@ -1019,6 +1019,28 @@ ReplaceSuperFile(const varstring lsuperfn,const varstring lfn,const varstring by
 FinishSuperFileTransaction(boolean rollback=false);
 */
 
+class CImplicitSuperTransaction
+{
+    IDistributedFileTransaction *transaction;
+public:
+    CImplicitSuperTransaction(IDistributedFileTransaction *_transaction)
+    {
+        if (!_transaction->active()) // then created implicitly
+        {
+            transaction = _transaction;
+            transaction->start();
+        }
+        else
+            transaction = NULL;
+    }
+    ~CImplicitSuperTransaction()
+    {
+        if (transaction)
+            transaction->commit();
+    }
+};
+
+
 static bool lookupSuperFile(ICodeContext *ctx, const char *lsuperfn, Owned<IDistributedSuperFile> &file, bool throwerr, StringBuffer &lsfn, bool allowforeign, bool cacheFiles=false)
 {
     lsfn.clear();
@@ -1111,6 +1133,7 @@ FILESERVICES_API unsigned FILESERVICES_CALL fsGetSuperFileSubCount(ICodeContext
     Owned<ISimpleSuperFileEnquiry> enq = getSimpleSuperFileEnquiry(ctx, lsuperfn);
     if (enq)
         return enq->numSubFiles();
+    CImplicitSuperTransaction implicitTransaction(ctx->querySuperFileTransaction());
     Owned<IDistributedSuperFile> file;
     StringBuffer lsfn;
     lookupSuperFile(ctx, lsuperfn, file, true, lsfn, true);
@@ -1128,6 +1151,7 @@ FILESERVICES_API char *  FILESERVICES_CALL fsGetSuperFileSubName(ICodeContext *c
             return CTXSTRDUP(parentCtx, "");
         return ret.detach();
     }
+    CImplicitSuperTransaction implicitTransaction(ctx->querySuperFileTransaction());
     Owned<IDistributedSuperFile> file;
     StringBuffer lsfn;
     lookupSuperFile(ctx, lsuperfn, file, true, lsfn, true);
@@ -1146,6 +1170,7 @@ FILESERVICES_API unsigned FILESERVICES_CALL fsFindSuperFileSubName(ICodeContext
         unsigned n = enq->findSubName(lfn.str());
         return (n==NotFound)?0:n+1;
     }
+    CImplicitSuperTransaction implicitTransaction(ctx->querySuperFileTransaction());
     Owned<IDistributedSuperFile> file;
     StringBuffer lsfn;
     lookupSuperFile(ctx, lsuperfn, file, true, lsfn, true);
@@ -1179,27 +1204,6 @@ FILESERVICES_API void FILESERVICES_CALL fsAddSuperFile(IGlobalCodeContext *gctx,
 }
 
 
-class CImplicitSuperTransaction
-{
-    IDistributedFileTransaction *transaction;
-public:
-    CImplicitSuperTransaction(IDistributedFileTransaction *_transaction)
-    {
-        if (!_transaction->active()) // then created implicitly
-        {
-            transaction = _transaction;
-            transaction->start();
-        }
-        else
-            transaction = NULL;
-    }
-    ~CImplicitSuperTransaction()
-    {
-        if (transaction)
-            transaction->commit();
-    }
-};
-
 FILESERVICES_API void FILESERVICES_CALL fslAddSuperFile(ICodeContext *ctx, const char *lsuperfn,const char *_lfn,unsigned atpos,bool addcontents, bool strict)
 {
     Owned<IDistributedSuperFile> file;
@@ -1697,6 +1701,7 @@ FILESERVICES_API void FILESERVICES_CALL fsSuperFileContents(ICodeContext *ctx, s
         }
     }
     else {
+        CImplicitSuperTransaction implicitTransaction(ctx->querySuperFileTransaction());
         Owned<IDistributedSuperFile> file;
         StringBuffer lsfn;
         lookupSuperFile(ctx, lsuperfn, file, true, lsfn, true);