ext4-code-cleanup-in-rb-tree-and-dir.patch

   1 ext4: improve some code in rb tree part of dir.c
   2
   3 From: Shen Feng <shen@cn.fujitsu.com>
   4
   5 *remove unnecessary code in free_rb_tree_fname
   6 *rename free_rb_tree_fname to ext4_htree_create_dir_info
   7  since it and ext4_htree_free_dir_info are a pair
   8 *replace kmalloc with kzalloc in ext4_htree_free_dir_info
   9
  10 All these make the code more readable and simple.
  11 PS: this patch is also suitable for ext3.
  12
  13 Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
  14 Signed-off-by: Mingming Cao <cmm@us.ibm.com>
  15 ---
  16  fs/ext4/dir.c |   14 ++++----------
  17  1 file changed, 4 insertions(+), 10 deletions(-)
  18
  19 Index: linux-2.6.26-rc4/fs/ext4/dir.c
  20 ===================================================================
  21 --- linux-2.6.26-rc4.orig/fs/ext4/dir.c 2008-05-29 10:52:29.000000000 -0700
  22 +++ linux-2.6.26-rc4/fs/ext4/dir.c      2008-05-29 10:52:33.000000000 -0700
  23 @@ -272,7 +272,7 @@ static void free_rb_tree_fname(struct rb
  24
  25         while (n) {
  26                 /* Do the node's children first */
  27 -               if ((n)->rb_left) {
  28 +               if (n->rb_left) {
  29                         n = n->rb_left;
  30                         continue;
  31                 }
  32 @@ -301,24 +301,18 @@ static void free_rb_tree_fname(struct rb
  33                         parent->rb_right = NULL;
  34                 n = parent;
  35         }
  36 -       root->rb_node = NULL;
  37  }
  38
  39
  40 -static struct dir_private_info *create_dir_info(loff_t pos)
  41 +static struct dir_private_info *ext4_htree_create_dir_info(loff_t pos)
  42  {
  43         struct dir_private_info *p;
  44
  45 -       p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL);
  46 +       p = kzalloc(sizeof(struct dir_private_info), GFP_KERNEL);
  47         if (!p)
  48                 return NULL;
  49 -       p->root.rb_node = NULL;
  50 -       p->curr_node = NULL;
  51 -       p->extra_fname = NULL;
  52 -       p->last_pos = 0;
  53         p->curr_hash = pos2maj_hash(pos);
  54         p->curr_minor_hash = pos2min_hash(pos);
  55 -       p->next_hash = 0;
  56         return p;
  57  }
  58
  59 @@ -433,7 +427,7 @@ static int ext4_dx_readdir(struct file *
  60         int     ret;
  61
  62         if (!info) {
  63 -               info = create_dir_info(filp->f_pos);
  64 +               info = ext4_htree_create_dir_info(filp->f_pos);
  65                 if (!info)
  66                         return -ENOMEM;
  67                 filp->private_data = info;