Commit 860784c8 authored by Robert Jennings's avatar Robert Jennings Committed by James Bottomley
Browse files

[SCSI] ibmvscsi: requeue while CRQ closed 



CRQ send errors that return with H_CLOSED should return with
SCSI_MLQUEUE_HOST_BUSY until firmware alerts the client of a CRQ
transport event.  The transport event will either reinitialize and
requeue the requests or fail and return IO with DID_ERROR.

To avoid failing the eh_* functions while re-attaching to the server
adapter this will retry for a period of time while ibmvscsi_send_srp_event
returns SCSI_MLQUEUE_HOST_BUSY.

In ibmvscsi_eh_abort_handler() the loop includes the search of the
event list.  The lock on the hostdata is dropped while waiting to try
again after failing ibmvscsi_send_srp_event.  The event could have been
purged if a login was in progress when the function was called.

In ibmvscsi_eh_device_reset_handler() the loop includes the call to
get_event_struct() because a failing call to ibmvscsi_send_srp_event()
will have freed the event struct.

Signed-off-by: default avatarRobert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent dc8875e1

drivers/scsi/ibmvscsi/ibmvscsi.c

+96 −55
Original line number Diff line number Diff line
@@ -629,6 +629,16 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct, 
		list_del(&evt_struct->list);

		del_timer(&evt_struct->timer);



		/* If send_crq returns H_CLOSED, return SCSI_MLQUEUE_HOST_BUSY.

		 * Firmware will send a CRQ with a transport event (0xFF) to

		 * tell this client what has happened to the transport.  This

		 * will be handled in ibmvscsi_handle_crq()

		 */

		if (rc == H_CLOSED) {

			dev_warn(hostdata->dev, "send warning. "

			         "Receive queue closed, will retry.\n");

			goto send_busy;

		}

		dev_err(hostdata->dev, "send error %d\n", rc);

		atomic_inc(&hostdata->request_limit);

		goto send_error;
@@ -976,11 +986,14 @@ static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd) 
	int rsp_rc;

	unsigned long flags;

	u16 lun = lun_from_dev(cmd->device);

	unsigned long wait_switch = 0;



	/* First, find this command in our sent list so we can figure

	 * out the correct tag

	 */

	spin_lock_irqsave(hostdata->host->host_lock, flags);

	wait_switch = jiffies + (init_timeout * HZ);

	do {

		found_evt = NULL;

		list_for_each_entry(tmp_evt, &hostdata->sent, list) {

			if (tmp_evt->cmnd == cmd) {
@@ -997,7 +1010,8 @@ static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd) 
		evt = get_event_struct(&hostdata->pool);

		if (evt == NULL) {

			spin_unlock_irqrestore(hostdata->host->host_lock, flags);

		sdev_printk(KERN_ERR, cmd->device, "failed to allocate abort event\n");

			sdev_printk(KERN_ERR, cmd->device,

				"failed to allocate abort event\n");

			return FAILED;

		}
@@ -1015,19 +1029,31 @@ static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd) 
		tsk_mgmt->tsk_mgmt_func = SRP_TSK_ABORT_TASK;

		tsk_mgmt->task_tag = (u64) found_evt;



	sdev_printk(KERN_INFO, cmd->device, "aborting command. lun 0x%lx, tag 0x%lx\n",

		    tsk_mgmt->lun, tsk_mgmt->task_tag);



		evt->sync_srp = &srp_rsp;



		init_completion(&evt->comp);

		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, init_timeout * 2);



		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)

			break;



		spin_unlock_irqrestore(hostdata->host->host_lock, flags);

		msleep(10);

		spin_lock_irqsave(hostdata->host->host_lock, flags);

	} while (time_before(jiffies, wait_switch));



	spin_unlock_irqrestore(hostdata->host->host_lock, flags);



	if (rsp_rc != 0) {

		sdev_printk(KERN_ERR, cmd->device,

			    "failed to send abort() event. rc=%d\n", rsp_rc);

		return FAILED;

	}



	sdev_printk(KERN_INFO, cmd->device,

                    "aborting command. lun 0x%lx, tag 0x%lx\n",

		    (((u64) lun) << 48), (u64) found_evt);



	wait_for_completion(&evt->comp);



	/* make sure we got a good response */
@@ -1099,12 +1125,16 @@ static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd) 
	int rsp_rc;

	unsigned long flags;

	u16 lun = lun_from_dev(cmd->device);

	unsigned long wait_switch = 0;



	spin_lock_irqsave(hostdata->host->host_lock, flags);

	wait_switch = jiffies + (init_timeout * HZ);

	do {

		evt = get_event_struct(&hostdata->pool);

		if (evt == NULL) {

			spin_unlock_irqrestore(hostdata->host->host_lock, flags);

		sdev_printk(KERN_ERR, cmd->device, "failed to allocate reset event\n");

			sdev_printk(KERN_ERR, cmd->device,

				"failed to allocate reset event\n");

			return FAILED;

		}
@@ -1121,19 +1151,30 @@ static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd) 
		tsk_mgmt->lun = ((u64) lun) << 48;

		tsk_mgmt->tsk_mgmt_func = SRP_TSK_LUN_RESET;



	sdev_printk(KERN_INFO, cmd->device, "resetting device. lun 0x%lx\n",

		    tsk_mgmt->lun);



		evt->sync_srp = &srp_rsp;



		init_completion(&evt->comp);

		rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, init_timeout * 2);



		if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)

			break;



		spin_unlock_irqrestore(hostdata->host->host_lock, flags);

		msleep(10);

		spin_lock_irqsave(hostdata->host->host_lock, flags);

	} while (time_before(jiffies, wait_switch));



	spin_unlock_irqrestore(hostdata->host->host_lock, flags);



	if (rsp_rc != 0) {

		sdev_printk(KERN_ERR, cmd->device,

			    "failed to send reset event. rc=%d\n", rsp_rc);

		return FAILED;

	}



	sdev_printk(KERN_INFO, cmd->device, "resetting device. lun 0x%lx\n",

		    (((u64) lun) << 48));



	wait_for_completion(&evt->comp);



	/* make sure we got a good response */

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