md: Use REQ_FAILFAST_* on metadata writes where appropriate
This can only be supported on personalities which ensure
that md_error() never causes an array to enter the 'failed'
state. i.e. if marking a device Faulty would cause some
data to be inaccessible, the device is status is left as
non-Faulty. This is true for RAID1 and RAID10.
If we get a failure writing metadata but the device doesn't
fail, it must be the last device so we re-write without
FAILFAST to improve chance of success. We also flag the
device as LastDev so that future metadata updates don't
waste time on failfast writes.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index bd8c884..af50866 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3729,6 +3729,7 @@ static int raid10_run(struct mddev *mddev)
size = raid10_size(mddev, 0, 0);
md_set_array_sectors(mddev, size);
mddev->resync_max_sectors = size;
+ set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
if (mddev->queue) {
int stripe = conf->geo.raid_disks *