Hello Don Brace,
The patch 6702d2c40f31: "scsi: smartpqi: Add support for RAID5 and
RAID6 writes" from Mar 11, 2021, leads to the following static
checker warning:
drivers/scsi/smartpqi/smartpqi_init.c:2664 pqi_calc_aio_r5_or_r6()
warn: previously used 'rmd->blocks_per_row' as divisor (see line 2622)
drivers/scsi/smartpqi/smartpqi_init.c
2607 rmd->r5or6_last_row_offset = do_div(tmpdiv, rmd->stripesize);
2608 tmpdiv = rmd->r5or6_last_row_offset;
2609 rmd->r5or6_last_row_offset = do_div(tmpdiv, rmd->blocks_per_row);
2610 tmpdiv = rmd->r5or6_first_row_offset;
2611 do_div(tmpdiv, rmd->strip_size);
2612 rmd->first_column = rmd->r5or6_first_column = tmpdiv;
2613 tmpdiv = rmd->r5or6_last_row_offset;
2614 do_div(tmpdiv, rmd->strip_size);
2615 rmd->r5or6_last_column = tmpdiv;
2616 #else
2617 rmd->first_row_offset = rmd->r5or6_first_row_offset =
2618 (u32)((rmd->first_block % rmd->stripesize) %
2619 rmd->blocks_per_row);
2620
2621 rmd->r5or6_last_row_offset =
2622 (u32)((rmd->last_block % rmd->stripesize) %
2623 rmd->blocks_per_row);
^^^^^^^^^^^^^^^^^^^
If ->blocks_per_row is zero then we are toasted long before the ...
2624
2625 rmd->first_column =
2626 rmd->r5or6_first_row_offset / rmd->strip_size;
2627 rmd->r5or6_first_column = rmd->first_column;
2628 rmd->r5or6_last_column = rmd->r5or6_last_row_offset / rmd->strip_size;
2629 #endif
2630 if (rmd->r5or6_first_column != rmd->r5or6_last_column)
2631 return PQI_RAID_BYPASS_INELIGIBLE;
2632
2633 /* Request is eligible. */
2634 rmd->map_row =
2635 ((u32)(rmd->first_row >> raid_map->parity_rotation_shift)) %
2636 get_unaligned_le16(&raid_map->row_cnt);
2637
2638 rmd->map_index = (rmd->first_group *
2639 (get_unaligned_le16(&raid_map->row_cnt) *
2640 rmd->total_disks_per_row)) +
2641 (rmd->map_row * rmd->total_disks_per_row) + rmd->first_column;
2642
2643 if (rmd->is_write) {
2644 u32 index;
2645
2646 /*
2647 * p_parity_it_nexus and q_parity_it_nexus are pointers to the
2648 * parity entries inside the device's raid_map.
2649 *
2650 * A device's RAID map is bounded by: number of RAID disks squared.
2651 *
2652 * The devices RAID map size is checked during device
2653 * initialization.
2654 */
2655 index = DIV_ROUND_UP(rmd->map_index + 1, rmd->total_disks_per_row);
2656 index *= rmd->total_disks_per_row;
2657 index -= get_unaligned_le16(&raid_map->metadata_disks_per_row);
2658
2659 rmd->p_parity_it_nexus = raid_map->disk_data[index].aio_handle;
2660 if (rmd->raid_level == SA_RAID_6) {
2661 rmd->q_parity_it_nexus = raid_map->disk_data[index + 1].aio_handle;
2662 rmd->xor_mult = raid_map->disk_data[rmd->map_index].xor_mult[1];
2663 }
2664 if (rmd->blocks_per_row == 0)
^^^^^^^^^^^^^^^^^^^^^^^^
... check on this line.
2665 return PQI_RAID_BYPASS_INELIGIBLE;
2666 #if BITS_PER_LONG == 32
2667 tmpdiv = rmd->first_block;
2668 do_div(tmpdiv, rmd->blocks_per_row);
2669 rmd->row = tmpdiv;
2670 #else
2671 rmd->row = rmd->first_block / rmd->blocks_per_row;
2672 #endif
2673 }
2674
2675 return 0;
2676 }
regards,
dan carpenter
