if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
                                &stripe_index);
-               if (op != BTRFS_MAP_WRITE && op != BTRFS_MAP_GET_READ_MIRRORS)
+               if (!need_full_stripe(op))
                        mirror_num = 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-               if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS)
+               if (need_full_stripe(op))
                        num_stripes = map->num_stripes;
                else if (mirror_num)
                        stripe_index = mirror_num - 1;
                }
 
        } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-               if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS) {
+               if (need_full_stripe(op)) {
                        num_stripes = map->num_stripes;
                } else if (mirror_num) {
                        stripe_index = mirror_num - 1;
                stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
                stripe_index *= map->sub_stripes;
 
-               if (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS)
+               if (need_full_stripe(op))
                        num_stripes = map->sub_stripes;
                else if (mirror_num)
                        stripe_index += mirror_num - 1;
                }
 
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-               if (need_raid_map &&
-                   (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS ||
-                    mirror_num > 1)) {
+               if (need_raid_map && (need_full_stripe(op) || mirror_num > 1)) {
                        /* push stripe_nr back to the start of the full stripe */
                        stripe_nr = div64_u64(raid56_full_stripe_start,
                                        stripe_len * nr_data_stripes(map));
                        /* We distribute the parity blocks across stripes */
                        div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
                                        &stripe_index);
-                       if ((op != BTRFS_MAP_WRITE &&
-                            op != BTRFS_MAP_GET_READ_MIRRORS) &&
-                           mirror_num <= 1)
+                       if (!need_full_stripe(op) && mirror_num <= 1)
                                mirror_num = 1;
                }
        } else {