btrfs: use next_state/prev_state in merge_state

We use rb_next/rb_prev and then get the entry for the adjacent items in
an extent io tree.  We have helpers for this, so convert merge_state to
use next_state/prev_state and simplify the code.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c
index 6ce0f7e..1616430 100644 (file)
--- a/fs/btrfs/extent-io-tree.c
+++ b/fs/btrfs/extent-io-tree.c
@@ -340,40 +340,31 @@ static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
 static void merge_state(struct extent_io_tree *tree, struct extent_state *state)
 {
        struct extent_state *other;
-       struct rb_node *other_node;
 
        if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
                return;
 
-       other_node = rb_prev(&state->rb_node);
-       if (other_node) {
-               other = rb_entry(other_node, struct extent_state, rb_node);
-               if (other->end == state->start - 1 &&
-                   other->state == state->state) {
-                       if (tree->private_data &&
-                           is_data_inode(tree->private_data))
-                               btrfs_merge_delalloc_extent(tree->private_data,
-                                                           state, other);
-                       state->start = other->start;
-                       rb_erase(&other->rb_node, &tree->state);
-                       RB_CLEAR_NODE(&other->rb_node);
-                       free_extent_state(other);
-               }
+       other = prev_state(state);
+       if (other && other->end == state->start - 1 &&
+           other->state == state->state) {
+               if (tree->private_data && is_data_inode(tree->private_data))
+                       btrfs_merge_delalloc_extent(tree->private_data,
+                                                   state, other);
+               state->start = other->start;
+               rb_erase(&other->rb_node, &tree->state);
+               RB_CLEAR_NODE(&other->rb_node);
+               free_extent_state(other);
        }
-       other_node = rb_next(&state->rb_node);
-       if (other_node) {
-               other = rb_entry(other_node, struct extent_state, rb_node);
-               if (other->start == state->end + 1 &&
-                   other->state == state->state) {
-                       if (tree->private_data &&
-                           is_data_inode(tree->private_data))
-                               btrfs_merge_delalloc_extent(tree->private_data,
-                                                           state, other);
-                       state->end = other->end;
-                       rb_erase(&other->rb_node, &tree->state);
-                       RB_CLEAR_NODE(&other->rb_node);
-                       free_extent_state(other);
-               }
+       other = next_state(state);
+       if (other && other->start == state->end + 1 &&
+           other->state == state->state) {
+               if (tree->private_data && is_data_inode(tree->private_data))
+                       btrfs_merge_delalloc_extent(tree->private_data, state,
+                                                   other);
+               state->end = other->end;
+               rb_erase(&other->rb_node, &tree->state);
+               RB_CLEAR_NODE(&other->rb_node);
+               free_extent_state(other);
        }
 }