1 files changed, 65 insertions, 26 deletions

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 387092724d2..820e6dbfd97 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -125,12 +125,11 @@ static int	max_safe_fds = 32;	/* default if not changed */
 /* these are the assigned bits in fdstate below: */
 #define FD_TEMPORARY		(1 << 0)	/* T = delete when closed */
 #define FD_XACT_TEMPORARY	(1 << 1)	/* T = delete at eoXact */
+#define FD_XACT_TRANSIENT	(1 << 2)	/* T = close (not delete) at aoXact,
+										 * but keep VFD */
 
-/*
- * Flag to tell whether it's worth scanning VfdCache looking for temp files to
- * close
- */
-static bool have_xact_temporary_files = false;
+/* Flag to tell whether there are files to close/delete at end of transaction */
+static bool have_pending_fd_cleanup = false;
 
 typedef struct vfd
 {
@@ -591,6 +590,7 @@ LruDelete(File file)
 	Vfd		   *vfdP;
 
 	Assert(file != 0);
+	Assert(!FileIsNotOpen(file));
 
 	DO_DB(elog(LOG, "LruDelete %d (%s)",
 			   file, VfdCache[file].fileName));
@@ -953,7 +953,7 @@ OpenTemporaryFile(bool interXact)
 		VfdCache[file].resowner = CurrentResourceOwner;
 
 		/* ensure cleanup happens at eoxact */
-		have_xact_temporary_files = true;
+		have_pending_fd_cleanup = true;
 	}
 
 	return file;
@@ -1027,6 +1027,25 @@ OpenTemporaryFileInTablespace(Oid tblspcOid, bool rejectError)
 }
 
 /*
+ * Set the transient flag on a file
+ *
+ * This flag tells CleanupTempFiles to close the kernel-level file descriptor
+ * (but not the VFD itself) at end of transaction.
+ */
+void
+FileSetTransient(File file)
+{
+	Vfd		  *vfdP;
+
+	Assert(FileIsValid(file));
+
+	vfdP = &VfdCache[file];
+	vfdP->fdstate |= FD_XACT_TRANSIENT;
+
+	have_pending_fd_cleanup = true;
+}
+
+/*
  * close a file when done with it
  */
 void
@@ -1778,8 +1797,9 @@ AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
  * particularly care which).  All still-open per-transaction temporary file
  * VFDs are closed, which also causes the underlying files to be deleted
  * (although they should've been closed already by the ResourceOwner
- * cleanup). Furthermore, all "allocated" stdio files are closed. We also
- * forget any transaction-local temp tablespace list.
+ * cleanup). Transient files have their kernel file descriptors closed.
+ * Furthermore, all "allocated" stdio files are closed. We also forget any
+ * transaction-local temp tablespace list.
  */
 void
 AtEOXact_Files(void)
@@ -1802,7 +1822,10 @@ AtProcExit_Files(int code, Datum arg)
 }
 
 /*
- * Close temporary files and delete their underlying files.
+ * General cleanup routine for fd.c.
+ *
+ * Temporary files are closed, and their underlying files deleted.
+ * Transient files are closed.
  *
  * isProcExit: if true, this is being called as the backend process is
  * exiting. If that's the case, we should remove all temporary files; if
@@ -1819,35 +1842,51 @@ CleanupTempFiles(bool isProcExit)
 	 * Careful here: at proc_exit we need extra cleanup, not just
 	 * xact_temporary files.
 	 */
-	if (isProcExit || have_xact_temporary_files)
+	if (isProcExit || have_pending_fd_cleanup)
 	{
 		Assert(FileIsNotOpen(0));		/* Make sure ring not corrupted */
 		for (i = 1; i < SizeVfdCache; i++)
 		{
 			unsigned short fdstate = VfdCache[i].fdstate;
 
-			if ((fdstate & FD_TEMPORARY) && VfdCache[i].fileName != NULL)
+			if (VfdCache[i].fileName != NULL)
 			{
-				/*
-				 * If we're in the process of exiting a backend process, close
-				 * all temporary files. Otherwise, only close temporary files
-				 * local to the current transaction. They should be closed by
-				 * the ResourceOwner mechanism already, so this is just a
-				 * debugging cross-check.
-				 */
-				if (isProcExit)
-					FileClose(i);
-				else if (fdstate & FD_XACT_TEMPORARY)
+				if (fdstate & FD_TEMPORARY)
+				{
+					/*
+					 * If we're in the process of exiting a backend process, close
+					 * all temporary files. Otherwise, only close temporary files
+					 * local to the current transaction. They should be closed by
+					 * the ResourceOwner mechanism already, so this is just a
+					 * debugging cross-check.
+					 */
+					if (isProcExit)
+						FileClose(i);
+					else if (fdstate & FD_XACT_TEMPORARY)
+					{
+						elog(WARNING,
+							 "temporary file %s not closed at end-of-transaction",
+							 VfdCache[i].fileName);
+						FileClose(i);
+					}
+				}
+				else if (fdstate & FD_XACT_TRANSIENT)
 				{
-					elog(WARNING,
-						 "temporary file %s not closed at end-of-transaction",
-						 VfdCache[i].fileName);
-					FileClose(i);
+					/*
+					 * Close the FD, and remove the entry from the LRU ring,
+					 * but also remove the flag from the VFD.  This is to
+					 * ensure that if the VFD is reused in the future for
+					 * non-transient access, we don't close it inappropriately
+					 * then.
+					 */
+					if (!FileIsNotOpen(i))
+						LruDelete(i);
+					VfdCache[i].fdstate &= ~FD_XACT_TRANSIENT;
 				}
 			}
 		}
 
-		have_xact_temporary_files = false;
+		have_pending_fd_cleanup = false;
 	}
 
 	/* Clean up "allocated" stdio files and dirs. */