Various places in raid1 and raid10 are calling raise_barrier when they really should call freeze_array. The former is only intended to be called from "make_request". The later has extra checks for 'nr_queued' and makes a call to flush_pending_writes(), so it is safe to call it from within the management thread. Using raise_barrier will sometimes deadlock. Using freeze_array should not. As 'freeze_array' currently expects one request to be pending (in handle_read_error - the only previous caller), we need to pass it the number of pending requests (extra) to ignore. The deadlock was made particularly noticeable by commits 050b66152f87c7 (raid10) and 6b740b8d79252f13 (raid1) which appeared in 3.4, so the fix is appropriate for any -stable kernel since then. This patch probably won't apply directly to some early kernels and will need to be applied by hand. Cc: stable@xxxxxxxxxxxxxxx Reported-by: Alexander Lyakas <alex.bolshoy@xxxxxxxxx> Signed-off-by: NeilBrown <neilb@xxxxxxx> --------------010104070508080806050907 Content-Type: text/x-patch; name="0001-md-raid1-raid10-use-freeze_array-in-place-of-raise_b.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-md-raid1-raid10-use-freeze_array-in-place-of-raise_b.pa"; filename*1="tch"