tux3: Prepare to implement overwrite mode

This removes side effect to rq->key from dleaf2_read(). With this
modify, we can read extents without side effect by __dleaf2_read().

__dleaf2_read() is going to be used for overwrite mode.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
1 file changed