md: allow upper limit for resync/reshape to be set when array is read-only

Normally we only allow the upper limit for a reshape to be decreased
when the array not performing a sync/recovery/reshape, otherwise there
could be races.  But if an array is part-way through a reshape when it
is assembled the reshape is started immediately leaving no window
to set an upper bound.

If the array is started read-only, the reshape will be suspended until
the array becomes writable, so that provides a window during which it
is perfectly safe to reduce the upper limit of a reshape.

So: allow the upper limit (sync_max) to be reduced even if the reshape
thread is running, as long as the array is still read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2009-08-13 10:41:50 +10:00
parent 1a67dde0ab
commit 4d484a4a7a

View File

@ -3599,6 +3599,7 @@ max_sync_store(mddev_t *mddev, const char *buf, size_t len)
if (max < mddev->resync_min)
return -EINVAL;
if (max < mddev->resync_max &&
mddev->ro == 0 &&
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -EBUSY;