zbd: disable crossing from conventional to sequential zones

zbd: disable crossing from conventional to sequential zones

Write I/Os to conventional zones may have the range that spans across
zone boundaries. Such writes may cause I/O errors when its next zone
is a sequential zone.

To avoid such I/O errors, check for the cross over from a conventional
to a sequential zone. When the write crosses the boundary, shrink the
I/O length to fit within the first zone. If the offset is too close to
the end of the zone, wrap it around to the beginning of the same zone.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>