[PATCH] libceph : client only want latest osdmap. If the gap with the latest version exceeds the threshold, mon will send the fullosdmap instead of incremental osdmap

[simon gao <simon29rock@gmail.com>]

Fix: https://tracker.ceph.com/issues/43421
Signed-off-by: simon gao <simon29rock@gmail.com>
---
 include/linux/ceph/ceph_fs.h | 1 +
 net/ceph/mon_client.c        | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index ebf5ba6..9dcc132 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -208,6 +208,7 @@ struct ceph_client_mount {
 } __attribute__ ((packed));
 
 #define CEPH_SUBSCRIBE_ONETIME    1  /* i want only 1 update after have */
+#define CEPH_SUBSCRIBE_LATEST_OSDMAP   2  /* i want the latest fullmap, for client */ 
 
 struct ceph_mon_subscribe_item {
 	__le64 start;
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 3d8c801..8d67671 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -349,7 +349,8 @@ static bool __ceph_monc_want_map(struct ceph_mon_client *monc, int sub,
 {
 	__le64 start = cpu_to_le64(epoch);
 	u8 flags = !continuous ? CEPH_SUBSCRIBE_ONETIME : 0;
-
+	if (CEPH_SUB_OSDMAP == sub)
+            flags |= CEPH_SUBSCRIBE_LATEST_OSDMAP;
 	dout("%s %s epoch %u continuous %d\n", __func__, ceph_sub_str[sub],
 	     epoch, continuous);
 
-- 
1.8.3.1