md: never update metadata when array is read-only.
Normally we don't even try to update the metadata if
the array is read-only. However future patches
will increase the number of things that can happen on a read-only
array, so it is safest to explicitly disable this.
Every time that mddev->ro is set to 0, either
- md_update_sb will be called again (at least if MD_CHANGE_DEVS
is set) or
- the mddev->thread is scheduled, which will also run
md_update_sb if needed.
So this is safe: if the array ever become read-write the
metadata will be updated.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index aeceedfc..c6e44a8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2411,6 +2411,11 @@
int nospares = 0;
int any_badblocks_changed = 0;
+ if (mddev->ro) {
+ if (force_change)
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ return;
+ }
repeat:
/* First make sure individual recovery_offsets are correct */
rdev_for_each(rdev, mddev) {