[sheepdog] [PATCH v2 2/2] sheep: don't start recovery if cluster was shutdowned

[Liu Yuan]

Add a new field in the config file to indicate shutdown status. The layout of
config file isn't modified, just find a free slot to hold shutdown status.

Signed-off-by: Liu Yuan <namei.unix at gmail.com>
---
 sheep/config.c     |   14 +++++++++++++-
 sheep/group.c      |    4 +++-
 sheep/ops.c        |    6 ++++++
 sheep/sheep_priv.h |    2 ++
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/sheep/config.c b/sheep/config.c
index 67198c0..1770ed1 100644
--- a/sheep/config.c
+++ b/sheep/config.c
@@ -19,7 +19,8 @@ static struct sheepdog_config {
 	uint16_t flags;
 	uint8_t copies;
 	uint8_t store[STORE_LEN];
-	uint8_t __pad[3];
+	uint8_t shutdown;
+	uint8_t __pad[2];
 	uint16_t version;
 	uint64_t space;
 } config;
@@ -171,6 +172,17 @@ bool is_cluster_formatted(void)
 	return cinfo.ctime != 0;
 }
 
+int set_cluster_shutdown(bool down)
+{
+	config.shutdown = down;
+	return write_config();
+}
+
+bool was_cluster_shutdowned(void)
+{
+	return config.shutdown;
+}
+
 static inline __attribute__((used)) void __sd_config_format_build_bug_ons(void)
 {
 	/* never called, only for checking BUILD_BUG_ON()s */
diff --git a/sheep/group.c b/sheep/group.c
index d063fcd..2b37090 100644
--- a/sheep/group.c
+++ b/sheep/group.c
@@ -660,10 +660,12 @@ static void update_cluster_info(const struct cluster_info *cinfo,
 
 			start_recovery(main_thread_get(current_vnode_info),
 				       old_vnode_info, true);
-		} else
+		} else if (!was_cluster_shutdowned()) {
 			start_recovery(main_thread_get(current_vnode_info),
 				       main_thread_get(current_vnode_info),
 				       false);
+		}
+		set_cluster_shutdown(false);
 	}
 
 	put_vnode_info(old_vnode_info);
diff --git a/sheep/ops.c b/sheep/ops.c
index f2d0a4d..3a0c16d 100644
--- a/sheep/ops.c
+++ b/sheep/ops.c
@@ -273,6 +273,12 @@ static int cluster_shutdown(const struct sd_req *req, struct sd_rsp *rsp,
 			    void *data)
 {
 	sys->cinfo.status = SD_STATUS_SHUTDOWN;
+	if (!node_in_recovery() && set_cluster_shutdown(true) != SD_RES_SUCCESS)
+		/*
+		 * It's okay we failed to set 'shutdown', just start recovery
+		 * after restart blindly.
+		 */
+		sd_err("failed to set cluster as shutdown");
 	return SD_RES_SUCCESS;
 }
 
diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
index 52b6b05..bb3ebbb 100644
--- a/sheep/sheep_priv.h
+++ b/sheep/sheep_priv.h
@@ -326,6 +326,8 @@ int get_cluster_config(struct cluster_info *cinfo);
 int set_node_space(uint64_t space);
 int get_node_space(uint64_t *space);
 bool is_cluster_formatted(void);
+bool was_cluster_shutdowned(void);
+int set_cluster_shutdown(bool);
 
 int store_file_write(void *buffer, size_t len);
 void *store_file_read(void);
-- 
1.7.9.5