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/raid1.c b/drivers/md/raid1.c
index d24adc5..4006a9b 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2988,6 +2988,7 @@ static int raid1_run(struct mddev *mddev)
mddev->thread = conf->thread;
conf->thread = NULL;
mddev->private = conf;
+ set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));