scsi: Improve requeuing behavior

EXPORT_SYMBOL(scsi_init_io);

/**

 * scsi_initialize_rq - initialize struct scsi_cmnd.req

 * scsi_initialize_rq - initialize struct scsi_cmnd partially

 * @rq: Request associated with the SCSI command to be initialized.

 *

 * This function initializes the members of struct scsi_cmnd that must be

 * initialized before request processing starts and that won't be

 * reinitialized if a SCSI command is requeued.

 *

 * Called from inside blk_get_request() for pass-through requests and from

 * inside scsi_init_command() for filesystem requests.

 */

	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);

	scsi_req_init(&cmd->req);

	cmd->jiffies_at_alloc = jiffies;

	cmd->retries = 0;

}

EXPORT_SYMBOL(scsi_initialize_rq);

	void *prot = cmd->prot_sdb;

	struct request *rq = blk_mq_rq_from_pdu(cmd);

	unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS;

	unsigned long jiffies_at_alloc;

	int retries;

	if (!blk_rq_is_scsi(rq) && !(flags & SCMD_INITIALIZED)) {

		flags |= SCMD_INITIALIZED;

		scsi_initialize_rq(rq);

	}

	jiffies_at_alloc = cmd->jiffies_at_alloc;

	retries = cmd->retries;

	/* zero out the cmd, except for the embedded scsi_request */

	memset((char *)cmd + sizeof(cmd->req), 0,

		sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size);

	cmd->prot_sdb = prot;

	cmd->flags = flags;

	INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);

	cmd->jiffies_at_alloc = jiffies;

	cmd->jiffies_at_alloc = jiffies_at_alloc;

	cmd->retries = retries;

	scsi_add_cmd_to_list(cmd);

}