Perform a write operation asynchronously
@param write_op operation to perform
@param io the ioctx that the object is in
@param completion what to do when operation has been attempted
@param oid the object id
@param mtime the time to set the mtime to, NULL for the current time
@param flags flags to apply to the entire operation (LIBRADOS_OPERATION_*)
Perform a write operation asynchronously @param write_op operation to perform @param io the ioctx that the object is in @param completion what to do when operation has been attempted @param oid the object id @param mtime the time to set the mtime to, NULL for the current time @param flags flags to apply to the entire operation (LIBRADOS_OPERATION_*)