[sheepdog] [PATCH v6 12/17] sheep: update store format version to v5

[Hitoshi Mitake]

From: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>

This patchset introduces two important change for sheep store:
1. generational reference counting: adding ledger object and expand
   inode object for generation reference
2. changing a place of btree_counter in inode object

Incrementing SD_FORMAT_VERSION in either of them would be
confusing. So this independent patch updates the number.

Cc: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
Cc: Valerio Pachera <sirio81 at gmail.com>
Cc: Alessandro Bolgia <alessandro at extensys.it>
Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
---
 sheep/config.c  |  2 +-
 sheep/migrate.c | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/sheep/config.c b/sheep/config.c
index 9a0217b..beb6509 100644
--- a/sheep/config.c
+++ b/sheep/config.c
@@ -11,7 +11,7 @@
 
 #include "sheep_priv.h"
 
-#define SD_FORMAT_VERSION 0x0004
+#define SD_FORMAT_VERSION 0x0005
 #define SD_CONFIG_SIZE 40
 
 static struct sheepdog_config {
diff --git a/sheep/migrate.c b/sheep/migrate.c
index 0d69fa1..e405f8a 100644
--- a/sheep/migrate.c
+++ b/sheep/migrate.c
@@ -496,6 +496,12 @@ static int migrate_from_v3_to_v4(void)
 	return 0;
 }
 
+static int migrate_from_v4_to_v5(void)
+{
+	panic("not implemented yet");
+	return -1;
+}
+
 static int (*migrate[])(void) = {
 	migrate_from_v0_to_v1, /* from 0.4.0 or 0.5.0 to 0.5.1 */
 	migrate_from_v1_to_v2, /* from 0.5.x to 0.6.0 */
@@ -506,6 +512,16 @@ static int (*migrate[])(void) = {
 	 * produced by the commit 79706e07a068
 	 */
 	migrate_from_v3_to_v4,
+
+	/*
+	 * from v0.8.x to v0.9.y
+	 *
+	 * introduced changes:
+	 * 1. generational reference counting: adding ledger object and expand
+	 *    inode object for generation reference
+	 * 2. changing a place of btree_counter in inode object
+	 */
+	migrate_from_v4_to_v5,
 };
 
 int sd_migrate_store(int from, int to)
-- 
1.8.3.2