Move functions related to temporary file management to tempfile.c

Like in the few previous commits, the idea is that only functions
related to the Virtual File Descriptor abstraction remain in fd.c.
This commit moves functions related to creating and deleting temporary
files and managing temporary dirs in tablespaces to a separate source
file.

This mostly a mechanical move. Note the split of the end-of-xact and
process-exit functions, however. tempfile.c now registers the
process-exit callback, but it relies on the CleanupTempFiles()
function provided by fd.c to do the work. CleanupTempFiles() now only
cleans up the temporary Files, it does not try to close AllocateDesc
handles. They should've been closed by end-of-xact cleanup already,
and if not, they will be closed at the impending process exit anyway.

Resetting the temporary tablespace list is moved to a new
AtEOXact_TempFiles() function, which is called from
Commit/AbortTransaction(), but not from all the cleanup routines where
AtEOXact_files() is called. Having a temporary tablespace list
requires an open transaction, so it doesn't need to be called at
non-transaction cleanup.

Author: hlinnaka

src/backend/access/transam/xact.c

@@ -62,6 +62,7 @@
 #include "storage/procarray.h"
 #include "storage/sinvaladt.h"
 #include "storage/smgr.h"
+#include "storage/tempfile.h"
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -2512,6 +2513,7 @@ CommitTransaction(void)
 	AtEOXact_Namespace(true, is_parallel_worker);
 	AtEOXact_SMgr();
 	AtEOXact_Files(true);
+	AtEOXact_TempFiles();
 	AtEOXact_ComboCid();
 	AtEOXact_HashTables(true);
 	AtEOXact_RI(true);
@@ -2808,6 +2810,7 @@ PrepareTransaction(void)
 	AtEOXact_Namespace(true, false);
 	AtEOXact_SMgr();
 	AtEOXact_Files(true);
+	AtEOXact_TempFiles();
 	AtEOXact_ComboCid();
 	AtEOXact_HashTables(true);
 	AtEOXact_RI(true);
@@ -3039,6 +3042,7 @@ AbortTransaction(void)
 		AtEOXact_Namespace(false, is_parallel_worker);
 		AtEOXact_SMgr();
 		AtEOXact_Files(false);
+		AtEOXact_TempFiles();
 		AtEOXact_ComboCid();
 		AtEOXact_HashTables(false);
 		AtEOXact_RI(false);

src/backend/backup/basebackup.c

@@ -43,6 +43,7 @@
 #include "storage/dsm_impl.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
+#include "storage/tempfile.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
 #include "utils/ps_status.h"

src/backend/commands/tablespace.c

@@ -74,6 +74,7 @@
 #include "storage/lwlock.h"
 #include "storage/procsignal.h"
 #include "storage/standby.h"
+#include "storage/tempfile.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"

src/backend/postmaster/postmaster.c

@@ -116,6 +116,7 @@
 #include "storage/pmsignal.h"
 #include "storage/proc.h"
 #include "storage/shmem_internal.h"
+#include "storage/tempfile.h"
 #include "tcop/backend_startup.h"
 #include "tcop/tcopprot.h"
 #include "utils/datetime.h"

src/backend/storage/file/Makefile

@@ -20,6 +20,7 @@ OBJS = \
 	fileset.o \
 	file_utils.o \
 	reinit.o \
-	sharedfileset.o
+	sharedfileset.o \
+	tempfile.o
 
 include $(top_srcdir)/src/backend/common.mk

src/backend/storage/file/buffile.c

@@ -52,6 +52,7 @@
 #include "storage/buffile.h"
 #include "storage/bufmgr.h"
 #include "storage/fd.h"
+#include "storage/tempfile.h"
 #include "utils/resowner.h"
 #include "utils/wait_event.h"
 

src/backend/storage/file/datadir.c

@@ -25,6 +25,7 @@
 #include "storage/datadir.h"
 #include "storage/fd.h"
 #include "storage/file_utils.h"
+#include "storage/tempfile.h"
 
 /* Define PG_FLUSH_DATA_WORKS if we have an implementation for pg_flush_data */
 #if defined(HAVE_SYNC_FILE_RANGE)