ocfs2: Add the 'cluster_stack' sysfs file.

Userspace can now query and specify the cluster stack in use via the
/sys/fs/ocfs2/cluster_stack file.  By default, it is 'o2cb', which is
the classic stack.  Thus, old tools that do not know how to modify this
file will work just fine.  The stack cannot be modified if there is a
live filesystem.

ocfs2_cluster_connect() now takes the expected cluster stack as an
argument.  This way, the filesystem and the stack glue ensure they are
speaking to the same backend.

If the stack is 'o2cb', the o2cb stack plugin is used.  For any other
value, the fsdlm stack plugin is selected.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index f62a9e4fc315..394d25a131a5 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2627,7 +2627,8 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
         }
 
         /* for now, uuid == domain */
-        status = ocfs2_cluster_connect(osb->uuid_str,
+        status = ocfs2_cluster_connect(osb->osb_cluster_stack,
+                                       osb->uuid_str,
                                        strlen(osb->uuid_str),
                                        ocfs2_do_node_down, osb,
                                        &conn);