lustre/kernel_patches/patches/raid5-maxsectors-rhel5.patch

   1 diff -ru linux-orig/drivers/md/raid5.c linux-new/drivers/md/raid5.c
   2 --- linux-orig/drivers/md/raid5.c       2009-04-14 08:11:38.000000000 +1000
   3 +++ linux-new/drivers/md/raid5.c        2009-09-20 05:02:02.000000000 +1000
   4 @@ -3595,10 +3595,16 @@
   5         mddev->array_size =  mddev->size * (conf->previous_raid_disks -
   6                                             conf->max_degraded);
   7
   8 +       int stripe_size = conf->chunk_size * (conf->previous_raid_disks - conf->max_degraded);
   9 +
  10         /* in order to support large I/Os */
  11 -       blk_queue_max_sectors(mddev->queue, conf->chunk_size * conf->previous_raid_disks >> 9);
  12 -       mddev->queue->max_phys_segments = conf->chunk_size * (conf->previous_raid_disks - conf->max_degraded) >> PAGE_SHIFT;
  13 -       mddev->queue->max_hw_segments = conf->chunk_size * conf->previous_raid_disks >> PAGE_SHIFT;;
  14 +       blk_queue_max_sectors(mddev->queue, stripe_size >> 9);
  15 +       /* KTVM: set default max_sectors the same as the max_hw_sectors set above */
  16 +       mddev->queue->max_sectors = mddev->queue->max_hw_sectors;
  17 +       printk("%s: setting max_sectors = %d, max_hw_sectors = %d\n", mdname(mddev), mddev->queue->max_sectors, mddev->queue->max_hw_sectors);
  18 +
  19 +       mddev->queue->max_phys_segments = stripe_size >> PAGE_SHIFT;
  20 +       mddev->queue->max_hw_segments = stripe_size >> PAGE_SHIFT;;
  21
  22         /* raid5 device is able to do zcopy right now. */
  23         mddev->queue->backing_dev_info.capabilities |= BDI_CAP_PAGE_CONSTANT_WRITE;