fs/ext4: use rbtree postorder iteration helper instead of opencoding

Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Michel Lespinasse <walken@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 3f11656bd72e3c4e667bc666320a2f9e84d1bd4f..41eb9dcfac7e3ebc7b8e2099a80c892caabbfb19 100644 (file)
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -180,37 +180,12 @@ int ext4_setup_system_zone(struct super_block *sb)
 /* Called when the filesystem is unmounted */
 void ext4_release_system_zone(struct super_block *sb)
 {
-       struct rb_node  *n = EXT4_SB(sb)->system_blks.rb_node;
-       struct rb_node  *parent;
-       struct ext4_system_zone *entry;
+       struct ext4_system_zone *entry, *n;
 
-       while (n) {
-               /* Do the node's children first */
-               if (n->rb_left) {
-                       n = n->rb_left;
-                       continue;
-               }
-               if (n->rb_right) {
-                       n = n->rb_right;
-                       continue;
-               }
-               /*
-                * The node has no children; free it, and then zero
-                * out parent's link to it.  Finally go to the
-                * beginning of the loop and try to free the parent
-                * node.
-                */
-               parent = rb_parent(n);
-               entry = rb_entry(n, struct ext4_system_zone, node);
+       rbtree_postorder_for_each_entry_safe(entry, n,
+                       &EXT4_SB(sb)->system_blks, node)
                kmem_cache_free(ext4_system_zone_cachep, entry);
-               if (!parent)
-                       EXT4_SB(sb)->system_blks = RB_ROOT;
-               else if (parent->rb_left == n)
-                       parent->rb_left = NULL;
-               else if (parent->rb_right == n)
-                       parent->rb_right = NULL;
-               n = parent;
-       }
+
        EXT4_SB(sb)->system_blks = RB_ROOT;
 }
 

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 680bb3388919a444b25e7dc0ee660b92ad475ce2..d638c57e996e6f775143cfac459cc7eccb607f3b 100644 (file)
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -353,41 +353,16 @@ struct fname {
  */
 static void free_rb_tree_fname(struct rb_root *root)
 {
-       struct rb_node  *n = root->rb_node;
-       struct rb_node  *parent;
-       struct fname    *fname;
-
-       while (n) {
-               /* Do the node's children first */
-               if (n->rb_left) {
-                       n = n->rb_left;
-                       continue;
-               }
-               if (n->rb_right) {
-                       n = n->rb_right;
-                       continue;
-               }
-               /*
-                * The node has no children; free it, and then zero
-                * out parent's link to it.  Finally go to the
-                * beginning of the loop and try to free the parent
-                * node.
-                */
-               parent = rb_parent(n);
-               fname = rb_entry(n, struct fname, rb_hash);
+       struct fname *fname, *next;
+
+       rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
                while (fname) {
                        struct fname *old = fname;
                        fname = fname->next;
                        kfree(old);
                }
-               if (!parent)
-                       *root = RB_ROOT;
-               else if (parent->rb_left == n)
-                       parent->rb_left = NULL;
-               else if (parent->rb_right == n)
-                       parent->rb_right = NULL;
-               n = parent;
-       }
+
+       *root = RB_ROOT;
 }