ext4: improve some code in rb tree part of dir.c

* remove unnecessary code in free_rb_tree_fname

* rename free_rb_tree_fname to ext4_htree_create_dir_info
  since it and ext4_htree_free_dir_info are a pair

* replace kmalloc with kzalloc in ext4_htree_free_dir_info

All these make the code more readable and simple.
PS: this patch is also suitable for ext3.

Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 4 insertions, 10 deletions

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 2bf0331ea194..5ed5108766c1 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -272,7 +272,7 @@ static void free_rb_tree_fname(struct rb_root *root)
 
         while (n) {
                 /* Do the node's children first */
-                if ((n)->rb_left) {
+                if (n->rb_left) {
                         n = n->rb_left;
                         continue;
                 }
@@ -301,24 +301,18 @@ static void free_rb_tree_fname(struct rb_root *root)
                         parent->rb_right = NULL;
                 n = parent;
         }
-        root->rb_node = NULL;
 }
 
 
-static struct dir_private_info *create_dir_info(loff_t pos)
+static struct dir_private_info *ext4_htree_create_dir_info(loff_t pos)
 {
         struct dir_private_info *p;
 
-        p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL);
+        p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
         if (!p)
                 return NULL;
-        p->root.rb_node = NULL;
-        p->curr_node = NULL;
-        p->extra_fname = NULL;
-        p->last_pos = 0;
         p->curr_hash = pos2maj_hash(pos);
         p->curr_minor_hash = pos2min_hash(pos);
-        p->next_hash = 0;
         return p;
 }
 
@@ -433,7 +427,7 @@ static int ext4_dx_readdir(struct file * filp,
         int     ret;
 
         if (!info) {
-                info = create_dir_info(filp->f_pos);
+                info = ext4_htree_create_dir_info(filp->f_pos);
                 if (!info)
                         return -ENOMEM;
                 filp->private_data = info;