I don't like the layering here. The re-execution of the same command for both reading and writing the data from/to the backend device already looks sketchy here due to doubling work of task attribute handling, the various state bits, etc. And it will only get more complicated when the required locking is added. In addition we have all that confusion about overloading the data direction. I think the way this should be handled is: - cmd->execute_cmd gets set to a new sbc_emulate_compare_and_write - sbc_emulate_compare_and_write does all the setup for the locking, sets up the read buffer, then calls ops->execute_rw to do the read. The complete callback does the comparism, then calls ops->execute_rw to do the write, and the second time we hit the complete callback we teard down the read buffer, stop the locking, etc. This also avoids bloating the command with another function pointer or having to change all execute_cmd prototypes. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
