ocfs2: Add refcount tree lock mechanism.

Implement locking around struct ocfs2_refcount_tree.  This protects
all read/write operations on refcount trees.  ocfs2_refcount_tree
has its own lock and its own caching_info, protecting buffers among
multiple nodes.

User must call ocfs2_lock_refcount_tree before his operation on
the tree and unlock it after that.

ocfs2_refcount_trees are referenced by the block number of the
refcount tree root block, So we create an rb-tree on the ocfs2_super
to look them up.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index e35a5052ce3..8b606217697 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -69,6 +69,7 @@
 #include "ver.h"
 #include "xattr.h"
 #include "quota.h"
+#include "refcounttree.h"
 
 #include "buffer_head_io.h"
 
@@ -1858,6 +1859,8 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err)
 
         ocfs2_sync_blockdev(sb);
 
+        ocfs2_purge_refcount_trees(osb);
+
         /* No cluster connection means we've failed during mount, so skip
          * all the steps which depended on that to complete. */
         if (osb->cconn) {
@@ -2064,6 +2067,8 @@ static int ocfs2_initialize_super(struct super_block *sb,
                 goto bail;
         }
 
+        osb->osb_rf_lock_tree = RB_ROOT;
+
         osb->s_feature_compat =
                 le32_to_cpu(OCFS2_RAW_SB(di)->s_feature_compat);
         osb->s_feature_ro_compat =