md: only count actual openers as access which prevent a 'stop'
Open isn't the only thing that increments ->active. e.g. reading
/proc/mdstat will increment it briefly. So to avoid false positives
in testing for concurrent access, introduce a new counter that counts
just the number of times the md device it open.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 6f72b47..4bef479 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -215,7 +215,8 @@
int in_sync; /* know to not need resync */
struct mutex reconfig_mutex;
- atomic_t active;
+ atomic_t active; /* general refcount */
+ atomic_t openers; /* number of active opens */
int changed; /* true if we might need to reread partition info */
int degraded; /* whether md should consider