3 files changed, 27 insertions, 21 deletions
diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c
index d158bb7a19f..f41563a0a48 100644
--- a/src/backend/storage/ipc/procsignal.c
+++ b/src/backend/storage/ipc/procsignal.c
@@ -28,6 +28,7 @@
 #include "storage/latch.h"
 #include "storage/proc.h"
 #include "storage/shmem.h"
+#include "storage/smgr.h"
 #include "storage/sinval.h"
 #include "tcop/tcopprot.h"
 #include "utils/memutils.h"
@@ -94,7 +95,6 @@ static ProcSignalSlot *MyProcSignalSlot = NULL;
 static bool CheckProcSignal(ProcSignalReason reason);
 static void CleanupProcSignalState(int status, Datum arg);
 static void ResetProcSignalBarrierBits(uint32 flags);
-static bool ProcessBarrierPlaceholder(void);
 static inline int GetNumProcSignalSlots(void);
 
 /*
@@ -536,8 +536,8 @@ ProcessProcSignalBarrier(void)
 				type = (ProcSignalBarrierType) pg_rightmost_one_pos32(flags);
 				switch (type)
 				{
-					case PROCSIGNAL_BARRIER_PLACEHOLDER:
-						processed = ProcessBarrierPlaceholder();
+					case PROCSIGNAL_BARRIER_SMGRRELEASE:
+						processed = ProcessBarrierSmgrRelease();
 						break;
 				}
 
@@ -603,24 +603,6 @@ ResetProcSignalBarrierBits(uint32 flags)
 	InterruptPending = true;
 }
 
-static bool
-ProcessBarrierPlaceholder(void)
-{
-	/*
-	 * XXX. This is just a placeholder until the first real user of this
-	 * machinery gets committed. Rename PROCSIGNAL_BARRIER_PLACEHOLDER to
-	 * PROCSIGNAL_BARRIER_SOMETHING_ELSE where SOMETHING_ELSE is something
-	 * appropriately descriptive. Get rid of this function and instead have
-	 * ProcessBarrierSomethingElse. Most likely, that function should live in
-	 * the file pertaining to that subsystem, rather than here.
-	 *
-	 * The return value should be 'true' if the barrier was successfully
-	 * absorbed and 'false' if not. Note that returning 'false' can lead to
-	 * very frequent retries, so try hard to make that an uncommon case.
-	 */
-	return true;
-}
-
 /*
  * CheckProcSignal - check to see if a particular reason has been
  * signaled, and clear the signal flag.  Should be called after receiving
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index d26c915f90e..879f647dbc2 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -549,6 +549,12 @@ mdclose(SMgrRelation reln, ForkNumber forknum)
 	}
 }
 
+void
+mdrelease(void)
+{
+	closeAllVfds();
+}
+
 /*
  *	mdprefetch() -- Initiate asynchronous read of the specified block of a relation
  */
diff --git a/src/backend/storage/smgr/smgr.c b/src/backend/storage/smgr/smgr.c
index eb701dce576..d71a557a352 100644
--- a/src/backend/storage/smgr/smgr.c
+++ b/src/backend/storage/smgr/smgr.c
@@ -41,6 +41,7 @@ typedef struct f_smgr
 {
 	void		(*smgr_init) (void);	/* may be NULL */
 	void		(*smgr_shutdown) (void);	/* may be NULL */
+	void		(*smgr_release) (void); /* may be NULL */
 	void		(*smgr_open) (SMgrRelation reln);
 	void		(*smgr_close) (SMgrRelation reln, ForkNumber forknum);
 	void		(*smgr_create) (SMgrRelation reln, ForkNumber forknum,
@@ -69,6 +70,7 @@ static const f_smgr smgrsw[] = {
 	{
 		.smgr_init = mdinit,
 		.smgr_shutdown = NULL,
+		.smgr_release = mdrelease,
 		.smgr_open = mdopen,
 		.smgr_close = mdclose,
 		.smgr_create = mdcreate,
@@ -693,3 +695,19 @@ AtEOXact_SMgr(void)
 		smgrclose(rel);
 	}
 }
+
+/*
+ * This routine is called when we are ordered to release all open files by a
+ * ProcSignalBarrier.
+ */
+bool
+ProcessBarrierSmgrRelease(void)
+{
+	for (int i = 0; i < NSmgr; i++)
+	{
+		if (smgrsw[i].smgr_release)
+			smgrsw[i].smgr_release();
+	}
+
+	return true;
+}