btrfs: delayed-ref: Cleanup the unneeded functions.

Cleanup the rb_tree merge/insert/update functions, since now we use list
instead of rb_tree now.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 4dbc316..fc9563d 100644 (file)
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -84,87 +84,6 @@ static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
        return 0;
 }
 
-/*
- * entries in the rb tree are ordered by the byte number of the extent,
- * type of the delayed backrefs and content of delayed backrefs.
- */
-static int comp_entry(struct btrfs_delayed_ref_node *ref2,
-                     struct btrfs_delayed_ref_node *ref1,
-                     bool compare_seq)
-{
-       if (ref1->bytenr < ref2->bytenr)
-               return -1;
-       if (ref1->bytenr > ref2->bytenr)
-               return 1;
-       if (ref1->is_head && ref2->is_head)
-               return 0;
-       if (ref2->is_head)
-               return -1;
-       if (ref1->is_head)
-               return 1;
-       if (ref1->type < ref2->type)
-               return -1;
-       if (ref1->type > ref2->type)
-               return 1;
-       if (ref1->no_quota > ref2->no_quota)
-               return 1;
-       if (ref1->no_quota < ref2->no_quota)
-               return -1;
-       /* merging of sequenced refs is not allowed */
-       if (compare_seq) {
-               if (ref1->seq < ref2->seq)
-                       return -1;
-               if (ref1->seq > ref2->seq)
-                       return 1;
-       }
-       if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
-           ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
-               return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
-                                     btrfs_delayed_node_to_tree_ref(ref1),
-                                     ref1->type);
-       } else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY ||
-                  ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
-               return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2),
-                                     btrfs_delayed_node_to_data_ref(ref1));
-       }
-       BUG();
-       return 0;
-}
-
-/*
- * insert a new ref into the rbtree.  This returns any existing refs
- * for the same (bytenr,parent) tuple, or NULL if the new node was properly
- * inserted.
- */
-static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
-                                                 struct rb_node *node)
-{
-       struct rb_node **p = &root->rb_node;
-       struct rb_node *parent_node = NULL;
-       struct btrfs_delayed_ref_node *entry;
-       struct btrfs_delayed_ref_node *ins;
-       int cmp;
-
-       ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-       while (*p) {
-               parent_node = *p;
-               entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
-                                rb_node);
-
-               cmp = comp_entry(entry, ins, 1);
-               if (cmp < 0)
-                       p = &(*p)->rb_left;
-               else if (cmp > 0)
-                       p = &(*p)->rb_right;
-               else
-                       return entry;
-       }
-
-       rb_link_node(node, parent_node, p);
-       rb_insert_color(node, root);
-       return NULL;
-}
-
 /* insert a new ref to head ref rbtree */
 static struct btrfs_delayed_ref_head *htree_insert(struct rb_root *root,
                                                   struct rb_node *node)
@@ -277,57 +196,6 @@ static inline void drop_delayed_ref(struct btrfs_trans_handle *trans,
                trans->delayed_ref_updates--;
 }
 
-static int merge_ref(struct btrfs_trans_handle *trans,
-                    struct btrfs_delayed_ref_root *delayed_refs,
-                    struct btrfs_delayed_ref_head *head,
-                    struct btrfs_delayed_ref_node *ref, u64 seq)
-{
-       struct rb_node *node;
-       int mod = 0;
-       int done = 0;
-
-       node = rb_next(&ref->rb_node);
-       while (!done && node) {
-               struct btrfs_delayed_ref_node *next;
-
-               next = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-               node = rb_next(node);
-               if (seq && next->seq >= seq)
-                       break;
-               if (comp_entry(ref, next, 0))
-                       continue;
-
-               if (ref->action == next->action) {
-                       mod = next->ref_mod;
-               } else {
-                       if (ref->ref_mod < next->ref_mod) {
-                               struct btrfs_delayed_ref_node *tmp;
-
-                               tmp = ref;
-                               ref = next;
-                               next = tmp;
-                               done = 1;
-                       }
-                       mod = -next->ref_mod;
-               }
-
-               drop_delayed_ref(trans, delayed_refs, head, next);
-               ref->ref_mod += mod;
-               if (ref->ref_mod == 0) {
-                       drop_delayed_ref(trans, delayed_refs, head, ref);
-                       done = 1;
-               } else {
-                       /*
-                        * You can't have multiples of the same ref on a tree
-                        * block.
-                        */
-                       WARN_ON(ref->type == BTRFS_TREE_BLOCK_REF_KEY ||
-                               ref->type == BTRFS_SHARED_BLOCK_REF_KEY);
-               }
-       }
-       return done;
-}
-
 int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
                            struct btrfs_delayed_ref_root *delayed_refs,
                            u64 seq)
@@ -401,48 +269,6 @@ again:
 }
 
 /*
- * helper function to update an extent delayed ref in the
- * rbtree.  existing and update must both have the same
- * bytenr and parent
- *
- * This may free existing if the update cancels out whatever
- * operation it was doing.
- */
-static noinline void
-update_existing_ref(struct btrfs_trans_handle *trans,
-                   struct btrfs_delayed_ref_root *delayed_refs,
-                   struct btrfs_delayed_ref_head *head,
-                   struct btrfs_delayed_ref_node *existing,
-                   struct btrfs_delayed_ref_node *update)
-{
-       if (update->action != existing->action) {
-               /*
-                * this is effectively undoing either an add or a
-                * drop.  We decrement the ref_mod, and if it goes
-                * down to zero we just delete the entry without
-                * every changing the extent allocation tree.
-                */
-               existing->ref_mod--;
-               if (existing->ref_mod == 0)
-                       drop_delayed_ref(trans, delayed_refs, head, existing);
-               else
-                       WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
-                               existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
-       } else {
-               WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
-                       existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
-               /*
-                * the action on the existing ref matches
-                * the action on the ref we're trying to add.
-                * Bump the ref_mod by one so the backref that
-                * is eventually added/removed has the correct
-                * reference count
-                */
-               existing->ref_mod += update->ref_mod;
-       }
-}
-
-/*
  * Helper to insert the ref_node to the tail or merge with tail.
  *
  * Return 0 for insert.