md: add possibility to change data-offset for devices.
When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).
So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.
(As we didn't previous check that all 'pad' fields were zero,
we need a new FEATURE flag for this.
A (belatedly) check that all remaining 'pad' fields are
zero to avoid a repeat of this)
The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.
This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be. At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.
When a reshape finishes we will need to update the data_offset
and rdev->sectors. So provide an exported function to do that.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 0abbd34..3705585 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3561,7 +3561,7 @@
if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
rdev = conf->disks[i].rdev;
rdev_clear_badblocks(rdev, sh->sector,
- STRIPE_SECTORS);
+ STRIPE_SECTORS, 0);
rdev_dec_pending(rdev, conf->mddev);
}
if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
@@ -3570,7 +3570,7 @@
/* rdev have been moved down */
rdev = conf->disks[i].rdev;
rdev_clear_badblocks(rdev, sh->sector,
- STRIPE_SECTORS);
+ STRIPE_SECTORS, 0);
rdev_dec_pending(rdev, conf->mddev);
}
}
@@ -5505,10 +5505,14 @@
if (!check_stripe_cache(mddev))
return -ENOSPC;
- rdev_for_each(rdev, mddev)
+ rdev_for_each(rdev, mddev) {
+ /* Don't support changing data_offset yet */
+ if (rdev->new_data_offset != rdev->data_offset)
+ return -EINVAL;
if (!test_bit(In_sync, &rdev->flags)
&& !test_bit(Faulty, &rdev->flags))
spares++;
+ }
if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
/* Not enough devices even to make a degraded array