alloc.c

	struct ocfs2_extent_list *right_el;
	struct ocfs2_path *right_path = NULL;
	int subtree_index = 0;
	struct ocfs2_extent_list *el = path_leaf_el(left_path);
	struct buffer_head *bh = path_leaf_bh(left_path);
	struct buffer_head *root_bh = NULL;

	BUG_ON(index >= le16_to_cpu(el->l_next_free_rec));
	left_rec = &el->l_recs[index];

	if (index == le16_to_cpu(el->l_next_free_rec) - 1 &&
	    le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count)) {
		/* we meet with a cross extent block merge. */
		ret = ocfs2_get_right_path(inode, left_path, &right_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		right_el = path_leaf_el(right_path);
		next_free = le16_to_cpu(right_el->l_next_free_rec);
		BUG_ON(next_free <= 0);
		right_rec = &right_el->l_recs[0];
		if (ocfs2_is_empty_extent(right_rec)) {
			BUG_ON(next_free <= 1);
			right_rec = &right_el->l_recs[1];
		}

		BUG_ON(le32_to_cpu(left_rec->e_cpos) +
		       le16_to_cpu(left_rec->e_leaf_clusters) !=
		       le32_to_cpu(right_rec->e_cpos));

		subtree_index = ocfs2_find_subtree_root(inode,
							left_path, right_path);

		ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
						      handle->h_buffer_credits,
						      right_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		root_bh = left_path->p_node[subtree_index].bh;
		BUG_ON(root_bh != right_path->p_node[subtree_index].bh);

		ret = ocfs2_journal_access(handle, inode, root_bh,
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		for (i = subtree_index + 1;
		     i < path_num_items(right_path); i++) {
			ret = ocfs2_journal_access(handle, inode,
						   right_path->p_node[i].bh,
						   OCFS2_JOURNAL_ACCESS_WRITE);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_journal_access(handle, inode,
						   left_path->p_node[i].bh,
						   OCFS2_JOURNAL_ACCESS_WRITE);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}

	} else {
		BUG_ON(index == le16_to_cpu(el->l_next_free_rec) - 1);
		right_rec = &el->l_recs[index + 1];
	}

	ret = ocfs2_journal_access(handle, inode, bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	le16_add_cpu(&left_rec->e_leaf_clusters, -split_clusters);

	le32_add_cpu(&right_rec->e_cpos, -split_clusters);
	le64_add_cpu(&right_rec->e_blkno,
		     -ocfs2_clusters_to_blocks(inode->i_sb, split_clusters));
	le16_add_cpu(&right_rec->e_leaf_clusters, split_clusters);

	ocfs2_cleanup_merge(el, index);

	ret = ocfs2_journal_dirty(handle, bh);
	if (ret)
		mlog_errno(ret);

	if (right_path) {
		ret = ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
		if (ret)
			mlog_errno(ret);

		ocfs2_complete_edge_insert(inode, handle, left_path,
					   right_path, subtree_index);
	}
out:
	if (right_path)
		ocfs2_free_path(right_path);
	return ret;
}

static int ocfs2_get_left_path(struct inode *inode,
			       struct ocfs2_path *right_path,
			       struct ocfs2_path **ret_left_path)
{
	int ret;
	u32 left_cpos;
	struct ocfs2_path *left_path = NULL;

	*ret_left_path = NULL;

	/* This function shouldn't be called for non-trees. */
	BUG_ON(right_path->p_tree_depth == 0);

	ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb,
					    right_path, &left_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	/* This function shouldn't be called for the leftmost leaf. */
	BUG_ON(left_cpos == 0);

	left_path = ocfs2_new_path(path_root_bh(right_path),
				   path_root_el(right_path));
	if (!left_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_find_path(inode, left_path, left_cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	*ret_left_path = left_path;
out:
	if (ret)
		ocfs2_free_path(left_path);
	return ret;
}

/*
 * Remove split_rec clusters from the record at index and merge them
 * onto the tail of the record "before" it.
 * For index > 0, the "before" means the extent rec at index - 1.
 *
 * For index == 0, the "before" means the last record of the previous
 * extent block. And there is also a situation that we may need to
 * remove the rightmost leaf extent block in the right_path and change
 * the right path to indicate the new rightmost path.
 */
static int ocfs2_merge_rec_left(struct inode *inode,
				struct ocfs2_path *right_path,
				handle_t *handle,
				struct ocfs2_extent_rec *split_rec,
				struct ocfs2_cached_dealloc_ctxt *dealloc,
				struct ocfs2_extent_tree *et,
				int index)
{
	int ret, i, subtree_index = 0, has_empty_extent = 0;
	unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
	struct ocfs2_extent_rec *left_rec;
	struct ocfs2_extent_rec *right_rec;
	struct ocfs2_extent_list *el = path_leaf_el(right_path);
	struct buffer_head *bh = path_leaf_bh(right_path);
	struct buffer_head *root_bh = NULL;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_list *left_el;

	BUG_ON(index < 0);

	right_rec = &el->l_recs[index];
	if (index == 0) {
		/* we meet with a cross extent block merge. */
		ret = ocfs2_get_left_path(inode, right_path, &left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		left_el = path_leaf_el(left_path);
		BUG_ON(le16_to_cpu(left_el->l_next_free_rec) !=
		       le16_to_cpu(left_el->l_count));

		left_rec = &left_el->l_recs[
				le16_to_cpu(left_el->l_next_free_rec) - 1];
		BUG_ON(le32_to_cpu(left_rec->e_cpos) +
		       le16_to_cpu(left_rec->e_leaf_clusters) !=
		       le32_to_cpu(split_rec->e_cpos));

		subtree_index = ocfs2_find_subtree_root(inode,
							left_path, right_path);

		ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
						      handle->h_buffer_credits,
						      left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		root_bh = left_path->p_node[subtree_index].bh;
		BUG_ON(root_bh != right_path->p_node[subtree_index].bh);

		ret = ocfs2_journal_access(handle, inode, root_bh,
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		for (i = subtree_index + 1;
		     i < path_num_items(right_path); i++) {
			ret = ocfs2_journal_access(handle, inode,
						   right_path->p_node[i].bh,
						   OCFS2_JOURNAL_ACCESS_WRITE);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_journal_access(handle, inode,
						   left_path->p_node[i].bh,
						   OCFS2_JOURNAL_ACCESS_WRITE);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}
	} else {
		left_rec = &el->l_recs[index - 1];
		if (ocfs2_is_empty_extent(&el->l_recs[0]))
			has_empty_extent = 1;
	}

	ret = ocfs2_journal_access(handle, inode, bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (has_empty_extent && index == 1) {
		/*
		 * The easy case - we can just plop the record right in.
		 */
		*left_rec = *split_rec;

		has_empty_extent = 0;
	} else
		le16_add_cpu(&left_rec->e_leaf_clusters, split_clusters);

	le32_add_cpu(&right_rec->e_cpos, split_clusters);
	le64_add_cpu(&right_rec->e_blkno,
		     ocfs2_clusters_to_blocks(inode->i_sb, split_clusters));
	le16_add_cpu(&right_rec->e_leaf_clusters, -split_clusters);

	ocfs2_cleanup_merge(el, index);

	ret = ocfs2_journal_dirty(handle, bh);
	if (ret)
		mlog_errno(ret);

	if (left_path) {
		ret = ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
		if (ret)
			mlog_errno(ret);

		/*
		 * In the situation that the right_rec is empty and the extent
		 * block is empty also,  ocfs2_complete_edge_insert can't handle
		 * it and we need to delete the right extent block.
		 */
		if (le16_to_cpu(right_rec->e_leaf_clusters) == 0 &&
		    le16_to_cpu(el->l_next_free_rec) == 1) {

			ret = ocfs2_remove_rightmost_path(inode, handle,
							  right_path,
							  dealloc, et);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			/* Now the rightmost extent block has been deleted.
			 * So we use the new rightmost path.
			 */
			ocfs2_mv_path(right_path, left_path);
			left_path = NULL;
		} else
			ocfs2_complete_edge_insert(inode, handle, left_path,
						   right_path, subtree_index);
	}
out:
	if (left_path)
		ocfs2_free_path(left_path);
	return ret;
}

static int ocfs2_try_to_merge_extent(struct inode *inode,
				     handle_t *handle,
				     struct ocfs2_path *path,
				     int split_index,
				     struct ocfs2_extent_rec *split_rec,
				     struct ocfs2_cached_dealloc_ctxt *dealloc,
				     struct ocfs2_merge_ctxt *ctxt,
				     struct ocfs2_extent_tree *et)

{
	int ret = 0;
	struct ocfs2_extent_list *el = path_leaf_el(path);
	struct ocfs2_extent_rec *rec = &el->l_recs[split_index];

	BUG_ON(ctxt->c_contig_type == CONTIG_NONE);

	if (ctxt->c_split_covers_rec && ctxt->c_has_empty_extent) {
		/*
		 * The merge code will need to create an empty
		 * extent to take the place of the newly
		 * emptied slot. Remove any pre-existing empty
		 * extents - having more than one in a leaf is
		 * illegal.
		 */
		ret = ocfs2_rotate_tree_left(inode, handle, path,
					     dealloc, et);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
		split_index--;
		rec = &el->l_recs[split_index];
	}

	if (ctxt->c_contig_type == CONTIG_LEFTRIGHT) {
		/*
		 * Left-right contig implies this.
		 */
		BUG_ON(!ctxt->c_split_covers_rec);

		/*
		 * Since the leftright insert always covers the entire
		 * extent, this call will delete the insert record
		 * entirely, resulting in an empty extent record added to
		 * the extent block.
		 *
		 * Since the adding of an empty extent shifts
		 * everything back to the right, there's no need to
		 * update split_index here.
		 *
		 * When the split_index is zero, we need to merge it to the
		 * prevoius extent block. It is more efficient and easier
		 * if we do merge_right first and merge_left later.
		 */
		ret = ocfs2_merge_rec_right(inode, path,
					    handle, split_rec,
					    split_index);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		/*
		 * We can only get this from logic error above.
		 */
		BUG_ON(!ocfs2_is_empty_extent(&el->l_recs[0]));

		/* The merge left us with an empty extent, remove it. */
		ret = ocfs2_rotate_tree_left(inode, handle, path,
					     dealloc, et);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		rec = &el->l_recs[split_index];

		/*
		 * Note that we don't pass split_rec here on purpose -
		 * we've merged it into the rec already.
		 */
		ret = ocfs2_merge_rec_left(inode, path,
					   handle, rec,
					   dealloc, et,
					   split_index);

		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_rotate_tree_left(inode, handle, path,
					     dealloc, et);
		/*
		 * Error from this last rotate is not critical, so
		 * print but don't bubble it up.
		 */
		if (ret)
			mlog_errno(ret);
		ret = 0;
	} else {
		/*
		 * Merge a record to the left or right.
		 *
		 * 'contig_type' is relative to the existing record,
		 * so for example, if we're "right contig", it's to
		 * the record on the left (hence the left merge).
		 */
		if (ctxt->c_contig_type == CONTIG_RIGHT) {
			ret = ocfs2_merge_rec_left(inode,
						   path,
						   handle, split_rec,
						   dealloc, et,
						   split_index);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		} else {
			ret = ocfs2_merge_rec_right(inode,
						    path,
						    handle, split_rec,
						    split_index);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}
		}

		if (ctxt->c_split_covers_rec) {
			/*
			 * The merge may have left an empty extent in
			 * our leaf. Try to rotate it away.
			 */
			ret = ocfs2_rotate_tree_left(inode, handle, path,
						     dealloc, et);
			if (ret)
				mlog_errno(ret);
			ret = 0;
		}
	}

out:
	return ret;
}

static void ocfs2_subtract_from_rec(struct super_block *sb,
				    enum ocfs2_split_type split,
				    struct ocfs2_extent_rec *rec,
				    struct ocfs2_extent_rec *split_rec)
{
	u64 len_blocks;

	len_blocks = ocfs2_clusters_to_blocks(sb,
				le16_to_cpu(split_rec->e_leaf_clusters));

	if (split == SPLIT_LEFT) {
		/*
		 * Region is on the left edge of the existing
		 * record.
		 */
		le32_add_cpu(&rec->e_cpos,
			     le16_to_cpu(split_rec->e_leaf_clusters));
		le64_add_cpu(&rec->e_blkno, len_blocks);
		le16_add_cpu(&rec->e_leaf_clusters,
			     -le16_to_cpu(split_rec->e_leaf_clusters));
	} else {
		/*
		 * Region is on the right edge of the existing
		 * record.
		 */
		le16_add_cpu(&rec->e_leaf_clusters,
			     -le16_to_cpu(split_rec->e_leaf_clusters));
	}
}

/*
 * Do the final bits of extent record insertion at the target leaf
 * list. If this leaf is part of an allocation tree, it is assumed
 * that the tree above has been prepared.
 */
static void ocfs2_insert_at_leaf(struct ocfs2_extent_rec *insert_rec,
				 struct ocfs2_extent_list *el,
				 struct ocfs2_insert_type *insert,
				 struct inode *inode)
{
	int i = insert->ins_contig_index;
	unsigned int range;
	struct ocfs2_extent_rec *rec;

	BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);

	if (insert->ins_split != SPLIT_NONE) {
		i = ocfs2_search_extent_list(el, le32_to_cpu(insert_rec->e_cpos));
		BUG_ON(i == -1);
		rec = &el->l_recs[i];
		ocfs2_subtract_from_rec(inode->i_sb, insert->ins_split, rec,
					insert_rec);
		goto rotate;
	}

	/*
	 * Contiguous insert - either left or right.
	 */
	if (insert->ins_contig != CONTIG_NONE) {
		rec = &el->l_recs[i];
		if (insert->ins_contig == CONTIG_LEFT) {
			rec->e_blkno = insert_rec->e_blkno;
			rec->e_cpos = insert_rec->e_cpos;
		}
		le16_add_cpu(&rec->e_leaf_clusters,
			     le16_to_cpu(insert_rec->e_leaf_clusters));
		return;
	}

	/*
	 * Handle insert into an empty leaf.
	 */
	if (le16_to_cpu(el->l_next_free_rec) == 0 ||
	    ((le16_to_cpu(el->l_next_free_rec) == 1) &&
	     ocfs2_is_empty_extent(&el->l_recs[0]))) {
		el->l_recs[0] = *insert_rec;
		el->l_next_free_rec = cpu_to_le16(1);
		return;
	}

	/*
	 * Appending insert.
	 */
	if (insert->ins_appending == APPEND_TAIL) {
		i = le16_to_cpu(el->l_next_free_rec) - 1;
		rec = &el->l_recs[i];
		range = le32_to_cpu(rec->e_cpos)
			+ le16_to_cpu(rec->e_leaf_clusters);
		BUG_ON(le32_to_cpu(insert_rec->e_cpos) < range);

		mlog_bug_on_msg(le16_to_cpu(el->l_next_free_rec) >=
				le16_to_cpu(el->l_count),
				"inode %lu, depth %u, count %u, next free %u, "
				"rec.cpos %u, rec.clusters %u, "
				"insert.cpos %u, insert.clusters %u\n",
				inode->i_ino,
				le16_to_cpu(el->l_tree_depth),
				le16_to_cpu(el->l_count),
				le16_to_cpu(el->l_next_free_rec),
				le32_to_cpu(el->l_recs[i].e_cpos),
				le16_to_cpu(el->l_recs[i].e_leaf_clusters),
				le32_to_cpu(insert_rec->e_cpos),
				le16_to_cpu(insert_rec->e_leaf_clusters));
		i++;
		el->l_recs[i] = *insert_rec;
		le16_add_cpu(&el->l_next_free_rec, 1);
		return;
	}

rotate:
	/*
	 * Ok, we have to rotate.
	 *
	 * At this point, it is safe to assume that inserting into an
	 * empty leaf and appending to a leaf have both been handled
	 * above.
	 *
	 * This leaf needs to have space, either by the empty 1st
	 * extent record, or by virtue of an l_next_rec < l_count.
	 */
	ocfs2_rotate_leaf(el, insert_rec);
}

static void ocfs2_adjust_rightmost_records(struct inode *inode,
					   handle_t *handle,
					   struct ocfs2_path *path,
					   struct ocfs2_extent_rec *insert_rec)
{
	int ret, i, next_free;
	struct buffer_head *bh;
	struct ocfs2_extent_list *el;
	struct ocfs2_extent_rec *rec;

	/*
	 * Update everything except the leaf block.
	 */
	for (i = 0; i < path->p_tree_depth; i++) {
		bh = path->p_node[i].bh;
		el = path->p_node[i].el;

		next_free = le16_to_cpu(el->l_next_free_rec);
		if (next_free == 0) {
			ocfs2_error(inode->i_sb,
				    "Dinode %llu has a bad extent list",
				    (unsigned long long)OCFS2_I(inode)->ip_blkno);
			ret = -EIO;
			return;
		}

		rec = &el->l_recs[next_free - 1];

		rec->e_int_clusters = insert_rec->e_cpos;
		le32_add_cpu(&rec->e_int_clusters,
			     le16_to_cpu(insert_rec->e_leaf_clusters));
		le32_add_cpu(&rec->e_int_clusters,
			     -le32_to_cpu(rec->e_cpos));

		ret = ocfs2_journal_dirty(handle, bh);
		if (ret)
			mlog_errno(ret);

	}
}

static int ocfs2_append_rec_to_path(struct inode *inode, handle_t *handle,
				    struct ocfs2_extent_rec *insert_rec,
				    struct ocfs2_path *right_path,
				    struct ocfs2_path **ret_left_path)
{
	int ret, next_free;
	struct ocfs2_extent_list *el;
	struct ocfs2_path *left_path = NULL;

	*ret_left_path = NULL;

	/*
	 * This shouldn't happen for non-trees. The extent rec cluster
	 * count manipulation below only works for interior nodes.
	 */
	BUG_ON(right_path->p_tree_depth == 0);

	/*
	 * If our appending insert is at the leftmost edge of a leaf,
	 * then we might need to update the rightmost records of the
	 * neighboring path.
	 */
	el = path_leaf_el(right_path);
	next_free = le16_to_cpu(el->l_next_free_rec);
	if (next_free == 0 ||
	    (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0]))) {
		u32 left_cpos;

		ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, right_path,
						    &left_cpos);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		mlog(0, "Append may need a left path update. cpos: %u, "
		     "left_cpos: %u\n", le32_to_cpu(insert_rec->e_cpos),
		     left_cpos);

		/*
		 * No need to worry if the append is already in the
		 * leftmost leaf.
		 */
		if (left_cpos) {
			left_path = ocfs2_new_path(path_root_bh(right_path),
						   path_root_el(right_path));
			if (!left_path) {
				ret = -ENOMEM;
				mlog_errno(ret);
				goto out;
			}

			ret = ocfs2_find_path(inode, left_path, left_cpos);
			if (ret) {
				mlog_errno(ret);
				goto out;
			}

			/*
			 * ocfs2_insert_path() will pass the left_path to the
			 * journal for us.
			 */
		}
	}

	ret = ocfs2_journal_access_path(inode, handle, right_path);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	ocfs2_adjust_rightmost_records(inode, handle, right_path, insert_rec);

	*ret_left_path = left_path;
	ret = 0;
out:
	if (ret != 0)
		ocfs2_free_path(left_path);

	return ret;
}

static void ocfs2_split_record(struct inode *inode,
			       struct ocfs2_path *left_path,
			       struct ocfs2_path *right_path,
			       struct ocfs2_extent_rec *split_rec,
			       enum ocfs2_split_type split)
{
	int index;
	u32 cpos = le32_to_cpu(split_rec->e_cpos);
	struct ocfs2_extent_list *left_el = NULL, *right_el, *insert_el, *el;
	struct ocfs2_extent_rec *rec, *tmprec;

	right_el = path_leaf_el(right_path);;
	if (left_path)
		left_el = path_leaf_el(left_path);

	el = right_el;
	insert_el = right_el;
	index = ocfs2_search_extent_list(el, cpos);
	if (index != -1) {
		if (index == 0 && left_path) {
			BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));

			/*
			 * This typically means that the record
			 * started in the left path but moved to the
			 * right as a result of rotation. We either
			 * move the existing record to the left, or we
			 * do the later insert there.
			 *
			 * In this case, the left path should always
			 * exist as the rotate code will have passed
			 * it back for a post-insert update.
			 */

			if (split == SPLIT_LEFT) {
				/*
				 * It's a left split. Since we know
				 * that the rotate code gave us an
				 * empty extent in the left path, we
				 * can just do the insert there.
				 */
				insert_el = left_el;
			} else {
				/*
				 * Right split - we have to move the
				 * existing record over to the left
				 * leaf. The insert will be into the
				 * newly created empty extent in the
				 * right leaf.
				 */
				tmprec = &right_el->l_recs[index];
				ocfs2_rotate_leaf(left_el, tmprec);
				el = left_el;

				memset(tmprec, 0, sizeof(*tmprec));
				index = ocfs2_search_extent_list(left_el, cpos);
				BUG_ON(index == -1);
			}
		}
	} else {
		BUG_ON(!left_path);
		BUG_ON(!ocfs2_is_empty_extent(&left_el->l_recs[0]));
		/*
		 * Left path is easy - we can just allow the insert to
		 * happen.
		 */
		el = left_el;
		insert_el = left_el;
		index = ocfs2_search_extent_list(el, cpos);
		BUG_ON(index == -1);
	}

	rec = &el->l_recs[index];
	ocfs2_subtract_from_rec(inode->i_sb, split, rec, split_rec);
	ocfs2_rotate_leaf(insert_el, split_rec);
}

/*
 * This function only does inserts on an allocation b-tree. For tree
 * depth = 0, ocfs2_insert_at_leaf() is called directly.
 *
 * right_path is the path we want to do the actual insert
 * in. left_path should only be passed in if we need to update that
 * portion of the tree after an edge insert.
 */
static int ocfs2_insert_path(struct inode *inode,
			     handle_t *handle,
			     struct ocfs2_path *left_path,
			     struct ocfs2_path *right_path,
			     struct ocfs2_extent_rec *insert_rec,
			     struct ocfs2_insert_type *insert)
{
	int ret, subtree_index;
	struct buffer_head *leaf_bh = path_leaf_bh(right_path);

	if (left_path) {
		int credits = handle->h_buffer_credits;

		/*
		 * There's a chance that left_path got passed back to
		 * us without being accounted for in the
		 * journal. Extend our transaction here to be sure we
		 * can change those blocks.
		 */
		credits += left_path->p_tree_depth;

		ret = ocfs2_extend_trans(handle, credits);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}

		ret = ocfs2_journal_access_path(inode, handle, left_path);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

	/*
	 * Pass both paths to the journal. The majority of inserts
	 * will be touching all components anyway.
	 */
	ret = ocfs2_journal_access_path(inode, handle, right_path);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}

	if (insert->ins_split != SPLIT_NONE) {
		/*
		 * We could call ocfs2_insert_at_leaf() for some types
		 * of splits, but it's easier to just let one separate
		 * function sort it all out.
		 */
		ocfs2_split_record(inode, left_path, right_path,
				   insert_rec, insert->ins_split);

		/*
		 * Split might have modified either leaf and we don't
		 * have a guarantee that the later edge insert will
		 * dirty this for us.
		 */
		if (left_path)
			ret = ocfs2_journal_dirty(handle,
						  path_leaf_bh(left_path));
			if (ret)
				mlog_errno(ret);
	} else
		ocfs2_insert_at_leaf(insert_rec, path_leaf_el(right_path),
				     insert, inode);

	ret = ocfs2_journal_dirty(handle, leaf_bh);
	if (ret)
		mlog_errno(ret);

	if (left_path) {
		/*
		 * The rotate code has indicated that we need to fix
		 * up portions of the tree after the insert.
		 *
		 * XXX: Should we extend the transaction here?
		 */
		subtree_index = ocfs2_find_subtree_root(inode, left_path,
							right_path);
		ocfs2_complete_edge_insert(inode, handle, left_path,
					   right_path, subtree_index);
	}

	ret = 0;
out:
	return ret;
}

static int ocfs2_do_insert_extent(struct inode *inode,
				  handle_t *handle,
				  struct ocfs2_extent_tree *et,
				  struct ocfs2_extent_rec *insert_rec,
				  struct ocfs2_insert_type *type)
{
	int ret, rotate = 0;
	u32 cpos;
	struct ocfs2_path *right_path = NULL;
	struct ocfs2_path *left_path = NULL;
	struct ocfs2_extent_list *el;

	el = et->et_root_el;

	ret = ocfs2_journal_access(handle, inode, et->et_root_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	if (le16_to_cpu(el->l_tree_depth) == 0) {
		ocfs2_insert_at_leaf(insert_rec, el, type, inode);
		goto out_update_clusters;
	}

	right_path = ocfs2_new_path(et->et_root_bh, et->et_root_el);
	if (!right_path) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	/*
	 * Determine the path to start with. Rotations need the
	 * rightmost path, everything else can go directly to the
	 * target leaf.
	 */
	cpos = le32_to_cpu(insert_rec->e_cpos);
	if (type->ins_appending == APPEND_NONE &&
	    type->ins_contig == CONTIG_NONE) {
		rotate = 1;
		cpos = UINT_MAX;
	}

	ret = ocfs2_find_path(inode, right_path, cpos);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	/*
	 * Rotations and appends need special treatment - they modify
	 * parts of the tree's above them.
	 *
	 * Both might pass back a path immediate to the left of the
	 * one being inserted to. This will be cause
	 * ocfs2_insert_path() to modify the rightmost records of
	 * left_path to account for an edge insert.
	 *
	 * XXX: When modifying this code, keep in mind that an insert
	 * can wind up skipping both of these two special cases...
	 */
	if (rotate) {
		ret = ocfs2_rotate_tree_right(inode, handle, type->ins_split,
					      le32_to_cpu(insert_rec->e_cpos),
					      right_path, &left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}

		/*
		 * ocfs2_rotate_tree_right() might have extended the
		 * transaction without re-journaling our tree root.
		 */
		ret = ocfs2_journal_access(handle, inode, et->et_root_bh,
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	} else if (type->ins_appending == APPEND_TAIL
		   && type->ins_contig != CONTIG_LEFT) {
		ret = ocfs2_append_rec_to_path(inode, handle, insert_rec,
					       right_path, &left_path);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	ret = ocfs2_insert_path(inode, handle, left_path, right_path,
				insert_rec, type);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

out_update_clusters:
	if (type->ins_split == SPLIT_NONE)
		ocfs2_et_update_clusters(inode, et,
					 le16_to_cpu(insert_rec->e_leaf_clusters));

	ret = ocfs2_journal_dirty(handle, et->et_root_bh);
	if (ret)
		mlog_errno(ret);

out:
	ocfs2_free_path(left_path);
	ocfs2_free_path(right_path);

	return ret;
}

static enum ocfs2_contig_type
ocfs2_figure_merge_contig_type(struct inode *inode, struct ocfs2_path *path,
			       struct ocfs2_extent_list *el, int index,
			       struct ocfs2_extent_rec *split_rec)
{
	int status;