Commits
Xiao Ni committed 1d0ffd26420
RAID10 BUG_ON in raise_barrier when force is true and conf->barrier is 0 In raid10 reshape_request it gets max_sectors in read_balance. If the underlayer disks have bad blocks, the max_sectors is less than last. It will call goto read_more many times. It calls raise_barrier(conf, sectors_done != 0) every time. In this condition sectors_done is not 0. So the value passed to the argument force of raise_barrier is true. In raise_barrier it checks conf->barrier when force is true. If force is true and conf->barrier is 0, it panic. In this case reshape_request submits bio to under layer disks. And in the callback function of the bio it calls lower_barrier. If the bio finishes before calling raise_barrier again, it can trigger the BUG_ON. Add one pair of raise_barrier/lower_barrier to fix this bug. Signed-off-by: Xiao Ni <xni@redhat.com> Suggested-by: Neil Brown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>