[PATCH 05/14] md: update the optimal I/O size on reshape

[Christoph Hellwig]

The raid5 and raid10 drivers currently update the read-ahead size,
but not the optimal I/O size on reshape.  To prepare for deriving the
read-ahead size from the optimal I/O size make sure it is updated
as well.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/md/raid10.c | 22 ++++++++++++++--------
 drivers/md/raid5.c  | 10 ++++++++--
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 353288bc4cb706..552ee0058c118d 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3695,10 +3695,20 @@ static struct r10conf *setup_conf(struct mddev *mddev)
        return ERR_PTR(err);
 }
 
+static void raid10_set_io_opt(struct r10conf *conf)
+{
+       int raid_disks = conf->geo.raid_disks;
+
+       if (!(conf->geo.raid_disks % conf->geo.near_copies))
+               raid_disks /= conf->geo.near_copies;
+       blk_queue_io_opt(conf->mddev->queue, (conf->mddev->chunk_sectors << 9) *
+                        raid_disks);
+}
+
 static int raid10_run(struct mddev *mddev)
 {
        struct r10conf *conf;
-       int i, disk_idx, chunk_size;
+       int i, disk_idx;
        struct raid10_info *disk;
        struct md_rdev *rdev;
        sector_t size;
@@ -3734,18 +3744,13 @@ static int raid10_run(struct mddev *mddev)
        mddev->thread = conf->thread;
        conf->thread = NULL;
 
-       chunk_size = mddev->chunk_sectors << 9;
        if (mddev->queue) {
                blk_queue_max_discard_sectors(mddev->queue,
                                              mddev->chunk_sectors);
                blk_queue_max_write_same_sectors(mddev->queue, 0);
                blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
-               blk_queue_io_min(mddev->queue, chunk_size);
-               if (conf->geo.raid_disks % conf->geo.near_copies)
-                       blk_queue_io_opt(mddev->queue, chunk_size * 
conf->geo.raid_disks);
-               else
-                       blk_queue_io_opt(mddev->queue, chunk_size *
-                                        (conf->geo.raid_disks / 
conf->geo.near_copies));
+               blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
+               raid10_set_io_opt(conf);
        }
 
        rdev_for_each(rdev, mddev) {
@@ -4719,6 +4724,7 @@ static void end_reshape(struct r10conf *conf)
                stripe /= conf->geo.near_copies;
                if (conf->mddev->queue->backing_dev_info->ra_pages < 2 * stripe)
                        conf->mddev->queue->backing_dev_info->ra_pages = 2 * 
stripe;
+               raid10_set_io_opt(conf);
        }
        conf->fullsync = 0;
 }
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 774ea893d47e21..f571b0eb5ec824 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7123,6 +7123,12 @@ static int only_parity(int raid_disk, int algo, int 
raid_disks, int max_degraded
        return 0;
 }
 
+static void raid5_set_io_opt(struct r5conf *conf)
+{
+       blk_queue_io_opt(conf->mddev->queue, (conf->chunk_sectors << 9) *
+                        (conf->raid_disks - conf->max_degraded));
+}
+
 static int raid5_run(struct mddev *mddev)
 {
        struct r5conf *conf;
@@ -7412,8 +7418,7 @@ static int raid5_run(struct mddev *mddev)
 
                chunk_size = mddev->chunk_sectors << 9;
                blk_queue_io_min(mddev->queue, chunk_size);
-               blk_queue_io_opt(mddev->queue, chunk_size *
-                                (conf->raid_disks - conf->max_degraded));
+               raid5_set_io_opt(conf);
                mddev->queue->limits.raid_partial_stripes_expensive = 1;
                /*
                 * We can only discard a whole stripe. It doesn't make sense to
@@ -8006,6 +8011,7 @@ static void end_reshape(struct r5conf *conf)
                                                   / PAGE_SIZE);
                        if (conf->mddev->queue->backing_dev_info->ra_pages < 2 
* stripe)
                                conf->mddev->queue->backing_dev_info->ra_pages 
= 2 * stripe;
+                       raid5_set_io_opt(conf);
                }
        }
 }
-- 
2.27.0