moving LastWrittenLSNCache to Neon Extension

.gitmodules

@@ -1,16 +1,16 @@
 [submodule "vendor/postgres-v14"]
 	path = vendor/postgres-v14
 	url = https://github.com/neondatabase/postgres.git
-	branch = REL_14_STABLE_neon
+	branch = thesuhas/move_lwlsn_neon_ext_v14
 [submodule "vendor/postgres-v15"]
 	path = vendor/postgres-v15
 	url = https://github.com/neondatabase/postgres.git
-	branch = REL_15_STABLE_neon
+	branch = thesuhas/move_lwlsn_neon_ext_v15
 [submodule "vendor/postgres-v16"]
 	path = vendor/postgres-v16
 	url = https://github.com/neondatabase/postgres.git
-	branch = REL_16_STABLE_neon
+	branch = thesuhas/move_lwlsn_neon_ext_v16
 [submodule "vendor/postgres-v17"]
 	path = vendor/postgres-v17
 	url = https://github.com/neondatabase/postgres.git
-	branch = REL_17_STABLE_neon
+	branch = move_lwlsn_neon_ext

pgxn/neon/Makefile

@@ -10,6 +10,7 @@ OBJS = \
 	libpagestore.o \
 	logical_replication_monitor.o \
 	neon.o \
+	neon_lwlc.o \
 	neon_pgversioncompat.o \
 	neon_perf_counters.o \
 	neon_utils.o \

pgxn/neon/file_cache.c

@@ -48,6 +48,7 @@
 #include "hll.h"
 #include "bitmap.h"
 #include "neon.h"
+#include "neon_lwlc.h"
 #include "neon_perf_counters.h"
 
 #define CriticalAssert(cond) do if (!(cond)) elog(PANIC, "LFC: assertion %s failed at %s:%d: ", #cond, __FILE__, __LINE__); while (0)
@@ -999,7 +1000,9 @@ lfc_prefetch(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 		LWLockRelease(lfc_lock);
 		return false;
 	}
-	lwlsn = GetLastWrittenLSN(rinfo, forknum, blkno);
+
+	lwlsn = neon_get_lwlsn(rinfo, forknum, blkno);
+
 	if (lwlsn > lsn)
 	{
 		elog(DEBUG1, "Skip LFC write for %d because LwLSN=%X/%X is greater than not_nodified_since LSN %X/%X",

pgxn/neon/neon.c

@@ -33,6 +33,7 @@
 
 #include "extension_server.h"
 #include "neon.h"
+#include "neon_lwlc.h"
 #include "control_plane_connector.h"
 #include "logical_replication_monitor.h"
 #include "unstable_extensions.h"
@@ -437,6 +438,8 @@ _PG_init(void)
 
 	pg_init_libpagestore();
 	pg_init_walproposer();
+	init_lwlc();
+
 	pagestore_smgr_init();
 	Custom_XLogReaderRoutines = NeonOnDemandXLogReaderRoutines;