1 files changed, 24 insertions, 11 deletions

diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 7817ad8659e..937b669e8cd 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -61,18 +61,29 @@ typedef struct ReplicationSlotOnDisk
 	uint32		version;
 	uint32		length;
 
+	/*
+	 * The actual data in the slot that follows can differ based on the above
+	 * 'version'.
+	 */
+
 	ReplicationSlotPersistentData slotdata;
 } ReplicationSlotOnDisk;
 
-/* size of the part of the slot that is version independent */
+/* size of version independent data */
 #define ReplicationSlotOnDiskConstantSize \
 	offsetof(ReplicationSlotOnDisk, slotdata)
-/* size of the slots that is not version indepenent */
-#define ReplicationSlotOnDiskDynamicSize \
+/* size of the part of the slot not covered by the checksum */
+#define SnapBuildOnDiskNotChecksummedSize \
+	offsetof(ReplicationSlotOnDisk, version)
+/* size of the part covered by the checksum */
+#define SnapBuildOnDiskChecksummedSize \
+	sizeof(ReplicationSlotOnDisk) - SnapBuildOnDiskNotChecksummedSize
+/* size of the slot data that is version dependant */
+#define ReplicationSlotOnDiskV2Size \
 	sizeof(ReplicationSlotOnDisk) - ReplicationSlotOnDiskConstantSize
 
 #define SLOT_MAGIC		0x1051CA1		/* format identifier */
-#define SLOT_VERSION	1		/* version for new files */
+#define SLOT_VERSION	2				/* version for new files */
 
 /* Control array for replication slot management */
 ReplicationSlotCtlData *ReplicationSlotCtl = NULL;
@@ -992,8 +1003,8 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel)
 
 	cp.magic = SLOT_MAGIC;
 	INIT_CRC32C(cp.checksum);
-	cp.version = 1;
-	cp.length = ReplicationSlotOnDiskDynamicSize;
+	cp.version = SLOT_VERSION;
+	cp.length = ReplicationSlotOnDiskV2Size;
 
 	SpinLockAcquire(&slot->mutex);
 
@@ -1002,8 +1013,9 @@ SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel)
 	SpinLockRelease(&slot->mutex);
 
 	COMP_CRC32C(cp.checksum,
-				(char *) (&cp) + ReplicationSlotOnDiskConstantSize,
-				ReplicationSlotOnDiskDynamicSize);
+				(char *) (&cp) + SnapBuildOnDiskNotChecksummedSize,
+				SnapBuildOnDiskChecksummedSize);
+	FIN_CRC32C(cp.checksum);
 
 	if ((write(fd, &cp, sizeof(cp))) != sizeof(cp))
 	{
@@ -1155,7 +1167,7 @@ RestoreSlotFromDisk(const char *name)
 				   path, cp.version)));
 
 	/* boundary check on length */
-	if (cp.length != ReplicationSlotOnDiskDynamicSize)
+	if (cp.length != ReplicationSlotOnDiskV2Size)
 		ereport(PANIC,
 				(errcode_for_file_access(),
 			   errmsg("replication slot file \"%s\" has corrupted length %u",
@@ -1182,8 +1194,9 @@ RestoreSlotFromDisk(const char *name)
 	/* now verify the CRC */
 	INIT_CRC32C(checksum);
 	COMP_CRC32C(checksum,
-				(char *) &cp + ReplicationSlotOnDiskConstantSize,
-				ReplicationSlotOnDiskDynamicSize);
+				(char *) &cp + SnapBuildOnDiskNotChecksummedSize,
+				SnapBuildOnDiskChecksummedSize);
+	FIN_CRC32C(checksum);
 
 	if (!EQ_CRC32C(checksum, cp.checksum))
 		ereport(PANIC,