aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/md
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/raid5.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b86ceba04f6f..269b7771a30b 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2633,6 +2633,84 @@ static int raid5_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_
2633 return max; 2633 return max;
2634} 2634}
2635 2635
2636
2637static int in_chunk_boundary(mddev_t *mddev, struct bio *bio)
2638{
2639 sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev);
2640 unsigned int chunk_sectors = mddev->chunk_size >> 9;
2641 unsigned int bio_sectors = bio->bi_size >> 9;
2642
2643 return chunk_sectors >=
2644 ((sector & (chunk_sectors - 1)) + bio_sectors);
2645}
2646
2647/*
2648 * The "raid5_align_endio" should check if the read succeeded and if it
2649 * did, call bio_endio on the original bio (having bio_put the new bio
2650 * first).
2651 * If the read failed..
2652 */
2653int raid5_align_endio(struct bio *bi, unsigned int bytes , int error)
2654{
2655 struct bio* raid_bi = bi->bi_private;
2656 if (bi->bi_size)
2657 return 1;
2658 bio_put(bi);
2659 bio_endio(raid_bi, bytes, error);
2660 return 0;
2661}
2662
2663static int chunk_aligned_read(request_queue_t *q, struct bio * raid_bio)
2664{
2665 mddev_t *mddev = q->queuedata;
2666 raid5_conf_t *conf = mddev_to_conf(mddev);
2667 const unsigned int raid_disks = conf->raid_disks;
2668 const unsigned int data_disks = raid_disks - 1;
2669 unsigned int dd_idx, pd_idx;
2670 struct bio* align_bi;
2671 mdk_rdev_t *rdev;
2672
2673 if (!in_chunk_boundary(mddev, raid_bio)) {
2674 printk("chunk_aligned_read : non aligned\n");
2675 return 0;
2676 }
2677 /*
2678 * use bio_clone to make a copy of the bio
2679 */
2680 align_bi = bio_clone(raid_bio, GFP_NOIO);
2681 if (!align_bi)
2682 return 0;
2683 /*
2684 * set bi_end_io to a new function, and set bi_private to the
2685 * original bio.
2686 */
2687 align_bi->bi_end_io = raid5_align_endio;
2688 align_bi->bi_private = raid_bio;
2689 /*
2690 * compute position
2691 */
2692 align_bi->bi_sector = raid5_compute_sector(raid_bio->bi_sector,
2693 raid_disks,
2694 data_disks,
2695 &dd_idx,
2696 &pd_idx,
2697 conf);
2698
2699 rcu_read_lock();
2700 rdev = rcu_dereference(conf->disks[dd_idx].rdev);
2701 if (rdev && test_bit(In_sync, &rdev->flags)) {
2702 align_bi->bi_bdev = rdev->bdev;
2703 atomic_inc(&rdev->nr_pending);
2704 rcu_read_unlock();
2705 generic_make_request(align_bi);
2706 return 1;
2707 } else {
2708 rcu_read_unlock();
2709 return 0;
2710 }
2711}
2712
2713
2636static int make_request(request_queue_t *q, struct bio * bi) 2714static int make_request(request_queue_t *q, struct bio * bi)
2637{ 2715{
2638 mddev_t *mddev = q->queuedata; 2716 mddev_t *mddev = q->queuedata;