cifs: convert tlink_tree to a rbtree

Radix trees are ideal when you want to track a bunch of pointers and
can't embed a tracking structure within the target of those pointers.
The tradeoff is an increase in memory, particularly if the tree is
sparse.

In CIFS, we use the tlink_tree to track tcon_link structs. A tcon_link
can never be in more than one tlink_tree, so there's no impediment to
using a rb_tree here instead of a radix tree.

Convert the new multiuser mount code to use a rb_tree instead. This
should reduce the memory required to manage the tlink_tree.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 79576dac336..e9a393c9c2c 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -15,7 +15,7 @@
  *   the GNU Lesser General Public License for more details.
  *
  */
-#include <linux/radix-tree.h>
+#include <linux/rbtree.h>
 
 #ifndef _CIFS_FS_SB_H
 #define _CIFS_FS_SB_H
@@ -42,7 +42,7 @@
 #define CIFS_MOUNT_MULTIUSER	0x20000 /* multiuser mount */
 
 struct cifs_sb_info {
-	struct radix_tree_root tlink_tree;
+	struct rb_root tlink_tree;
 	spinlock_t tlink_tree_lock;
 	struct tcon_link *master_tlink;
 	struct nls_table *local_nls;