Btrfs: more efficient inode tree replace operation
authorFilipe David Borba Manana <fdmanana@gmail.com>
Mon, 2 Sep 2013 11:19:13 +0000 (12:19 +0100)
committerChris Mason <chris.mason@fusionio.com>
Sat, 21 Sep 2013 14:58:55 +0000 (10:58 -0400)
Instead of removing the current inode from the red black tree
and then add the new one, just use the red black tree replace
operation, which is more efficient.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
fs/btrfs/inode.c

index 6091ba9d249419765da7cc1ea692c4e9fab21de0..abed81d936873a31c2cb2ebe2ff13ecd5e66fe08 100644 (file)
@@ -4688,11 +4688,11 @@ static void inode_tree_add(struct inode *inode)
        struct btrfs_inode *entry;
        struct rb_node **p;
        struct rb_node *parent;
+       struct rb_node *new = &BTRFS_I(inode)->rb_node;
        u64 ino = btrfs_ino(inode);
 
        if (inode_unhashed(inode))
                return;
-again:
        parent = NULL;
        spin_lock(&root->inode_lock);
        p = &root->inode_tree.rb_node;
@@ -4707,14 +4707,14 @@ again:
                else {
                        WARN_ON(!(entry->vfs_inode.i_state &
                                  (I_WILL_FREE | I_FREEING)));
-                       rb_erase(parent, &root->inode_tree);
+                       rb_replace_node(parent, new, &root->inode_tree);
                        RB_CLEAR_NODE(parent);
                        spin_unlock(&root->inode_lock);
-                       goto again;
+                       return;
                }
        }
-       rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
-       rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
+       rb_link_node(new, parent, p);
+       rb_insert_color(new, &root->inode_tree);
        spin_unlock(&root->inode_lock);
 }