btrfs_num_raid_stripes
const int num_stripes = btrfs_num_raid_stripes(item_size);
for (int i = 0; i < btrfs_num_raid_stripes(item_size); i++) {
num_stripes = btrfs_num_raid_stripes(btrfs_item_size(leaf, slot));
for (int i = 0; i < btrfs_num_raid_stripes(item_size); i++) {