ocfs2: Create specific get_extent_tree functions.

A caller knows what kind of extent tree they have.  There's no reason
they have to call ocfs2_get_extent_tree() with a NULL when they could
just as easily call a specific function to their type of extent tree.

Introduce ocfs2_dinode_get_extent_tree(),
ocfs2_xattr_tree_get_extent_tree(), and
ocfs2_xattr_value_get_extent_tree().  They only take the necessary
arguments, calling into the underlying __ocfs2_get_extent_tree() to do
the real work.

__ocfs2_get_extent_tree() is the old ocfs2_get_extent_tree(), but
without needing any switch-by-type logic.

ocfs2_get_extent_tree() is now a wrapper around the specific calls.  It
exists because a couple alloc.c functions can take et_type.  This will
go later.

Another benefit is that ocfs2_xattr_value_get_extent_tree() can take a
struct ocfs2_xattr_value_root* instead of void*.  This gives us
typechecking where we didn't have it before.

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

2 files changed, 56 insertions, 22 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 64f1af4e999e..7b08180a4c67 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -192,7 +192,7 @@ static int ocfs2_xattr_value_sanity_check(struct inode *inode,
         return 0;
 }
 
-static struct ocfs2_extent_tree_operations ocfs2_xattr_et_ops = {
+static struct ocfs2_extent_tree_operations ocfs2_xattr_value_et_ops = {
         .eo_set_last_eb_blk     = ocfs2_xattr_value_set_last_eb_blk,
         .eo_get_last_eb_blk     = ocfs2_xattr_value_get_last_eb_blk,
         .eo_update_clusters     = ocfs2_xattr_value_update_clusters,
@@ -256,27 +256,21 @@ static struct ocfs2_extent_tree_operations ocfs2_xattr_tree_et_ops = {
         .eo_fill_max_leaf_clusters = ocfs2_xattr_tree_fill_max_leaf_clusters,
 };
 
-static void ocfs2_get_extent_tree(struct ocfs2_extent_tree *et,
-                                  struct inode *inode,
-                                  struct buffer_head *bh,
-                                  enum ocfs2_extent_tree_type et_type,
-                                  void *obj)
+static void __ocfs2_get_extent_tree(struct ocfs2_extent_tree *et,
+                                    struct inode *inode,
+                                    struct buffer_head *bh,
+                                    void *obj,
+                                    enum ocfs2_extent_tree_type et_type,
+                                    struct ocfs2_extent_tree_operations *ops)
 {
         et->et_type = et_type;
+        et->et_ops = ops;
         get_bh(bh);
         et->et_root_bh = bh;
         if (!obj)
                 obj = (void *)bh->b_data;
         et->et_object = obj;
 
-        if (et_type == OCFS2_DINODE_EXTENT) {
-                et->et_ops = &ocfs2_dinode_et_ops;
-        } else if (et_type == OCFS2_XATTR_VALUE_EXTENT) {
-                et->et_ops = &ocfs2_xattr_et_ops;
-        } else if (et_type == OCFS2_XATTR_TREE_EXTENT) {
-                et->et_ops = &ocfs2_xattr_tree_et_ops;
-        }
-
         et->et_ops->eo_fill_root_el(et);
         if (!et->et_ops->eo_fill_max_leaf_clusters)
                 et->et_max_leaf_clusters = 0;
@@ -284,6 +278,49 @@ static void ocfs2_get_extent_tree(struct ocfs2_extent_tree *et,
                 et->et_ops->eo_fill_max_leaf_clusters(inode, et);
 }
 
+static void ocfs2_get_dinode_extent_tree(struct ocfs2_extent_tree *et,
+                                         struct inode *inode,
+                                         struct buffer_head *bh)
+{
+        __ocfs2_get_extent_tree(et, inode, bh, NULL, OCFS2_DINODE_EXTENT,
+                                &ocfs2_dinode_et_ops);
+}
+
+static void ocfs2_get_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
+                                             struct inode *inode,
+                                             struct buffer_head *bh)
+{
+        __ocfs2_get_extent_tree(et, inode, bh, NULL,
+                                OCFS2_XATTR_TREE_EXTENT,
+                                &ocfs2_xattr_tree_et_ops);
+}
+
+static void ocfs2_get_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
+                                             struct inode *inode,
+                                             struct buffer_head *bh,
+                                             struct ocfs2_xattr_value_root *xv)
+{
+        __ocfs2_get_extent_tree(et, inode, bh, xv,
+                                OCFS2_XATTR_VALUE_EXTENT,
+                                &ocfs2_xattr_value_et_ops);
+}
+
+static void ocfs2_get_extent_tree(struct ocfs2_extent_tree *et,
+                                  struct inode *inode,
+                                  struct buffer_head *bh,
+                                  enum ocfs2_extent_tree_type et_type,
+                                  void *obj)
+{
+        if (et_type == OCFS2_DINODE_EXTENT)
+                ocfs2_get_dinode_extent_tree(et, inode, bh);
+        else if (et_type == OCFS2_XATTR_VALUE_EXTENT)
+                ocfs2_get_xattr_tree_extent_tree(et, inode, bh);
+        else if (et_type == OCFS2_XATTR_TREE_EXTENT)
+                ocfs2_get_xattr_value_extent_tree(et, inode, bh, obj);
+        else
+                BUG();
+}
+
 static void ocfs2_put_extent_tree(struct ocfs2_extent_tree *et)
 {
         brelse(et->et_root_bh);
@@ -4432,8 +4469,7 @@ int ocfs2_dinode_insert_extent(struct ocfs2_super *osb,
         int status;
         struct ocfs2_extent_tree et;
 
-        ocfs2_get_extent_tree(&et, inode, root_bh, OCFS2_DINODE_EXTENT,
-                              NULL);
+        ocfs2_get_dinode_extent_tree(&et, inode, root_bh);
         status = ocfs2_insert_extent(osb, handle, inode, root_bh,
                                      cpos, start_blk, new_clusters,
                                      flags, meta_ac, &et);
@@ -4451,13 +4487,12 @@ int ocfs2_xattr_value_insert_extent(struct ocfs2_super *osb,
                                     u32 new_clusters,
                                     u8 flags,
                                     struct ocfs2_alloc_context *meta_ac,
-                                    void *obj)
+                                    struct ocfs2_xattr_value_root *xv)
 {
         int status;
         struct ocfs2_extent_tree et;
 
-        ocfs2_get_extent_tree(&et, inode, root_bh,
-                              OCFS2_XATTR_VALUE_EXTENT, obj);
+        ocfs2_get_xattr_value_extent_tree(&et, inode, root_bh, xv);
         status = ocfs2_insert_extent(osb, handle, inode, root_bh,
                                      cpos, start_blk, new_clusters,
                                      flags, meta_ac, &et);
@@ -4479,8 +4514,7 @@ int ocfs2_xattr_tree_insert_extent(struct ocfs2_super *osb,
         int status;
         struct ocfs2_extent_tree et;
 
-        ocfs2_get_extent_tree(&et, inode, root_bh, OCFS2_XATTR_TREE_EXTENT,
-                              NULL);
+        ocfs2_get_xattr_tree_extent_tree(&et, inode, root_bh);
         status = ocfs2_insert_extent(osb, handle, inode, root_bh,
                                      cpos, start_blk, new_clusters,
                                      flags, meta_ac, &et);
diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h
index 23c695ddaa52..5cc9a83cf1a1 100644
--- a/fs/ocfs2/alloc.h
+++ b/fs/ocfs2/alloc.h
@@ -56,7 +56,7 @@ int ocfs2_xattr_value_insert_extent(struct ocfs2_super *osb,
                                     u32 new_clusters,
                                     u8 flags,
                                     struct ocfs2_alloc_context *meta_ac,
-                                    void *private);
+                                    struct ocfs2_xattr_value_root *xv);
 int ocfs2_xattr_tree_insert_extent(struct ocfs2_super *osb,
                                    handle_t *handle,
                                    struct inode *inode,