ocfs2: Add an incompat feature flag OCFS2_FEATURE_INCOMPAT_CLUSTERINFO

OCFS2_FEATURE_INCOMPAT_CLUSTERINFO allows us to use sb->s_cluster_info for
both userspace and o2cb cluster stacks. It also allows us to extend cluster
info to include stack flags.

This patch also adds stackflags to sb->s_clusterinfo. It also introduces a
clusterinfo flag OCFS2_CLUSTER_O2CB_GLOBAL_HEARTBEAT to denote the enabled
global heartbeat mode.

This incompat flag can be set/cleared using tunefs.ocfs2 --fs-features. The
clusterinfo flag is set/cleared using tunefs.ocfs2 --update-cluster-stack.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>

1 files changed, 29 insertions, 2 deletions

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index c67003b6b5a2..d5496a792bdb 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -368,6 +368,8 @@ struct ocfs2_super
         struct ocfs2_alloc_stats alloc_stats;
         char dev_str[20];               /* "major,minor" of the device */
 
+        u8 osb_stackflags;
+
         char osb_cluster_stack[OCFS2_STACK_LABEL_LEN + 1];
         struct ocfs2_cluster_connection *cconn;
         struct ocfs2_lock_res osb_super_lockres;
@@ -601,10 +603,35 @@ static inline int ocfs2_is_soft_readonly(struct ocfs2_super *osb)
         return ret;
 }
 
-static inline int ocfs2_userspace_stack(struct ocfs2_super *osb)
+static inline int ocfs2_clusterinfo_valid(struct ocfs2_super *osb)
 {
         return (osb->s_feature_incompat &
-                OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK);
+                (OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK |
+                 OCFS2_FEATURE_INCOMPAT_CLUSTERINFO));
+}
+
+static inline int ocfs2_userspace_stack(struct ocfs2_super *osb)
+{
+        if (ocfs2_clusterinfo_valid(osb) &&
+            memcmp(osb->osb_cluster_stack, OCFS2_CLASSIC_CLUSTER_STACK,
+                   OCFS2_STACK_LABEL_LEN))
+                return 1;
+        return 0;
+}
+
+static inline int ocfs2_o2cb_stack(struct ocfs2_super *osb)
+{
+        if (ocfs2_clusterinfo_valid(osb) &&
+            !memcmp(osb->osb_cluster_stack, OCFS2_CLASSIC_CLUSTER_STACK,
+                   OCFS2_STACK_LABEL_LEN))
+                return 1;
+        return 0;
+}
+
+static inline int ocfs2_cluster_o2cb_global_heartbeat(struct ocfs2_super *osb)
+{
+        return ocfs2_o2cb_stack(osb) &&
+                (osb->osb_stackflags & OCFS2_CLUSTER_O2CB_GLOBAL_HEARTBEAT);
 }
 
 static inline int ocfs2_mount_local(struct ocfs2_super *osb)