[PATCH 4.9 116/151] ocfs2: remove ocfs2_is_o2cb_active()

[Greg Kroah-Hartman]

From: Gang He <ghe@xxxxxxxx>

commit a634644751c46238df58bbfe992e30c1668388db upstream.

Remove ocfs2_is_o2cb_active().  We have similar functions to identify
which cluster stack is being used via osb->osb_cluster_stack.

Secondly, the current implementation of ocfs2_is_o2cb_active() is not
totally safe.  Based on the design of stackglue, we need to get
ocfs2_stack_lock before using ocfs2_stack related data structures, and
that active_stack pointer can be NULL in the case of mount failure.

Link: http://lkml.kernel.org/r/1495441079-11708-1-git-send-email-ghe@xxxxxxxx
Signed-off-by: Gang He <ghe@xxxxxxxx>
Reviewed-by: Joseph Qi <jiangqi903@xxxxxxxxx>
Reviewed-by: Eric Ren <zren@xxxxxxxx>
Acked-by: Changwei Ge <ge.changwei@xxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/ocfs2/dlmglue.c   |    2 +-
 fs/ocfs2/stackglue.c |    6 ------
 fs/ocfs2/stackglue.h |    3 ---
 3 files changed, 1 insertion(+), 10 deletions(-)

--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -3421,7 +3421,7 @@ static int ocfs2_downconvert_lock(struct
 	 * we can recover correctly from node failure. Otherwise, we may get
 	 * invalid LVB in LKB, but without DLM_SBF_VALNOTVALIDÂbeing set.
 	 */
-	if (!ocfs2_is_o2cb_active() &&
+	if (ocfs2_userspace_stack(osb) &&
 	    lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
 		lvb = 1;
 
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -48,12 +48,6 @@ static char ocfs2_hb_ctl_path[OCFS2_MAX_
  */
 static struct ocfs2_stack_plugin *active_stack;
 
-inline int ocfs2_is_o2cb_active(void)
-{
-	return !strcmp(active_stack->sp_name, OCFS2_STACK_PLUGIN_O2CB);
-}
-EXPORT_SYMBOL_GPL(ocfs2_is_o2cb_active);
-
 static struct ocfs2_stack_plugin *ocfs2_stack_lookup(const char *name)
 {
 	struct ocfs2_stack_plugin *p;
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -298,9 +298,6 @@ void ocfs2_stack_glue_set_max_proto_vers
 int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
 void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
 
-/* In ocfs2_downconvert_lock(), we need to know which stack we are using */
-int ocfs2_is_o2cb_active(void);
-
 extern struct kset *ocfs2_kset;
 
 #endif  /* STACKGLUE_H */