On Thu, Jun 6, 2013 at 12:43 PM, Hannes Reinecke <hare@xxxxxxx> wrote: > When a command runs into a timeout we need to send an 'ABORT TASK' > TMF. This is typically done by the 'eh_abort_handler' LLDD callback. > > Conceptually, however, this function is a normal SCSI command, so > there is no need to enter the error handler. > > This patch implements a new scsi_abort_command() function which > invokes an asynchronous function scsi_eh_abort_handler() to > abort the commands via 'eh_abort_handler'. > > If the 'eh_abort_handler' returns SUCCESS or FAST_IO_FAIL the > command will be retried if possible. If no retries are allowed > the command will be returned immediately, as we have to assume > the TMF succeeded and the command is completed with the LLDD. > For any other return code from 'eh_abort_handler' the command > will be pushed onto the existing SCSI EH handler, or aborted > with DID_TIME_OUT if that fails. > Why would you do a retry at this low level? We already have a bad path, the IO may already be rerouted through another path and continuing with this IO here may interfere with the multipath handling. Baruch -- 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
