tree 4f24e56a076c2d544fbda272a85ba25e8d1e0242
parent a4a3d26d8757a30ae21724d8b0d79e00e113c38d
author NeilBrown <neilb@suse.com> 1437098762 +1000
committer NeilBrown <neilb@suse.com> 1441042653 +0200

md: be careful when testing resync_max against curr_resync_completed.

While it generally shouldn't happen, it is not impossible for
curr_resync_completed to exceed resync_max.
This can particularly happen when reshaping RAID5 - the current
status isn't copied to curr_resync_completed promptly, so when it
is, it can exceed resync_max.
This happens when the reshape is 'frozen', resync_max is set low,
and reshape is re-enabled.

Taking a difference between two unsigned numbers is always dangerous
anyway, so add a test to behave correctly if
   curr_resync_completed > resync_max

Signed-off-by: NeilBrown <neilb@suse.com>