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Commit 3d0e91f7 authored by Brian King's avatar Brian King Committed by James Bottomley
Browse files

[SCSI] ibmvscsi: Add eh_host_reset_handler 



Adds an eh_host_reset_handler to ibmvscsi which resets the connection
to the vscsi server. This patch also adds a timer to internally
issues commands to prevent client hangs in the case of a misbehaving
server. Tested by modifying the VIOS such that it would occasionally
drop one or more request in sequence.

Signed-off-by: default avatarBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 6c0a60ec

drivers/scsi/ibmvscsi/ibmvscsi.c

+106 −30
Original line number Diff line number Diff line
@@ -509,6 +509,70 @@ static int map_data_for_srp_cmd(struct scsi_cmnd *cmd, 
	return map_single_data(cmd, srp_cmd, dev);

}



/**

 * purge_requests: Our virtual adapter just shut down.  purge any sent requests

 * @hostdata:    the adapter

 */

static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)

{

	struct srp_event_struct *tmp_evt, *pos;

	unsigned long flags;



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

	list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {

		list_del(&tmp_evt->list);

		del_timer(&tmp_evt->timer);

		if (tmp_evt->cmnd) {

			tmp_evt->cmnd->result = (error_code << 16);

			unmap_cmd_data(&tmp_evt->iu.srp.cmd,

				       tmp_evt,

				       tmp_evt->hostdata->dev);

			if (tmp_evt->cmnd_done)

				tmp_evt->cmnd_done(tmp_evt->cmnd);

		} else if (tmp_evt->done)

			tmp_evt->done(tmp_evt);

		free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);

	}

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

}



/**

 * ibmvscsi_reset_host - Reset the connection to the server

 * @hostdata:	struct ibmvscsi_host_data to reset

*/

static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata)

{

	scsi_block_requests(hostdata->host);

	atomic_set(&hostdata->request_limit, 0);



	purge_requests(hostdata, DID_ERROR);

	if ((ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata)) ||

	    (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0)) ||

	    (vio_enable_interrupts(to_vio_dev(hostdata->dev)))) {

		atomic_set(&hostdata->request_limit, -1);

		dev_err(hostdata->dev, "error after reset\n");

	}



	scsi_unblock_requests(hostdata->host);

}



/**

 * ibmvscsi_timeout - Internal command timeout handler

 * @evt_struct:	struct srp_event_struct that timed out

 *

 * Called when an internally generated command times out

*/

static void ibmvscsi_timeout(struct srp_event_struct *evt_struct)

{

	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;



	dev_err(hostdata->dev, "Command timed out (%x). Resetting connection\n",

		evt_struct->iu.srp.cmd.opcode);



	ibmvscsi_reset_host(hostdata);

}





/* ------------------------------------------------------------

 * Routines for sending and receiving SRPs

 */
@@ -516,12 +580,14 @@ static int map_data_for_srp_cmd(struct scsi_cmnd *cmd, 
 * ibmvscsi_send_srp_event: - Transforms event to u64 array and calls send_crq()

 * @evt_struct:	evt_struct to be sent

 * @hostdata:	ibmvscsi_host_data of host

 * @timeout:	timeout in seconds - 0 means do not time command

 *

 * Returns the value returned from ibmvscsi_send_crq(). (Zero for success)

 * Note that this routine assumes that host_lock is held for synchronization

*/

static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,

				   struct ibmvscsi_host_data *hostdata)

				   struct ibmvscsi_host_data *hostdata,

				   unsigned long timeout)

{

	u64 *crq_as_u64 = (u64 *) &evt_struct->crq;

	int request_status;
@@ -577,9 +643,18 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct, 
	 */

	list_add_tail(&evt_struct->list, &hostdata->sent);



	init_timer(&evt_struct->timer);

	if (timeout) {

		evt_struct->timer.data = (unsigned long) evt_struct;

		evt_struct->timer.expires = jiffies + (timeout * HZ);

		evt_struct->timer.function = (void (*)(unsigned long))ibmvscsi_timeout;

		add_timer(&evt_struct->timer);

	}



	if ((rc =

	     ibmvscsi_send_crq(hostdata, crq_as_u64[0], crq_as_u64[1])) != 0) {

		list_del(&evt_struct->list);

		del_timer(&evt_struct->timer);



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

		atomic_inc(&hostdata->request_limit);
@@ -709,7 +784,7 @@ static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd, 
			offsetof(struct srp_indirect_buf, desc_list);

	}



	return ibmvscsi_send_srp_event(evt_struct, hostdata);

	return ibmvscsi_send_srp_event(evt_struct, hostdata, 0);

}



/* ------------------------------------------------------------
@@ -800,7 +875,7 @@ static void send_mad_adapter_info(struct ibmvscsi_host_data *hostdata) 
		return;

	}

	

	if (ibmvscsi_send_srp_event(evt_struct, hostdata)) {

	if (ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2)) {

		dev_err(hostdata->dev, "couldn't send ADAPTER_INFO_REQ!\n");

		dma_unmap_single(hostdata->dev,

				 addr,
@@ -889,7 +964,7 @@ static int send_srp_login(struct ibmvscsi_host_data *hostdata) 
	 */

	atomic_set(&hostdata->request_limit, 1);



	rc = ibmvscsi_send_srp_event(evt_struct, hostdata);

	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);

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

	dev_info(hostdata->dev, "sent SRP login\n");

	return rc;
@@ -969,7 +1044,7 @@ static int ibmvscsi_eh_abort_handler(struct scsi_cmnd *cmd) 


	evt->sync_srp = &srp_rsp;

	init_completion(&evt->comp);

	rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);

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

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

	if (rsp_rc != 0) {

		sdev_printk(KERN_ERR, cmd->device,
@@ -1077,7 +1152,7 @@ static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd) 


	evt->sync_srp = &srp_rsp;

	init_completion(&evt->comp);

	rsp_rc = ibmvscsi_send_srp_event(evt, hostdata);

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

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

	if (rsp_rc != 0) {

		sdev_printk(KERN_ERR, cmd->device,
@@ -1133,32 +1208,30 @@ static int ibmvscsi_eh_device_reset_handler(struct scsi_cmnd *cmd) 
}



/**

 * purge_requests: Our virtual adapter just shut down.  purge any sent requests

 * @hostdata:    the adapter

 * ibmvscsi_eh_host_reset_handler - Reset the connection to the server

 * @cmd:	struct scsi_cmnd having problems

*/

static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)

static int ibmvscsi_eh_host_reset_handler(struct scsi_cmnd *cmd)

{

	struct srp_event_struct *tmp_evt, *pos;

	unsigned long flags;

	unsigned long wait_switch = 0;

	struct ibmvscsi_host_data *hostdata =

		(struct ibmvscsi_host_data *)cmd->device->host->hostdata;



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

	list_for_each_entry_safe(tmp_evt, pos, &hostdata->sent, list) {

		list_del(&tmp_evt->list);

		if (tmp_evt->cmnd) {

			tmp_evt->cmnd->result = (error_code << 16);

			unmap_cmd_data(&tmp_evt->iu.srp.cmd, 

				       tmp_evt,	

				       tmp_evt->hostdata->dev);

			if (tmp_evt->cmnd_done)

				tmp_evt->cmnd_done(tmp_evt->cmnd);

		} else {

			if (tmp_evt->done) {

				tmp_evt->done(tmp_evt);

			}

		}

		free_event_struct(&tmp_evt->hostdata->pool, tmp_evt);

	dev_err(hostdata->dev, "Resetting connection due to error recovery\n");



	ibmvscsi_reset_host(hostdata);



	for (wait_switch = jiffies + (init_timeout * HZ);

	     time_before(jiffies, wait_switch) &&

		     atomic_read(&hostdata->request_limit) < 2;) {



		msleep(10);

	}

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



	if (atomic_read(&hostdata->request_limit) <= 0)

		return FAILED;



	return SUCCESS;

}



/**
@@ -1258,6 +1331,8 @@ void ibmvscsi_handle_crq(struct viosrp_crq *crq, 
		atomic_add(evt_struct->xfer_iu->srp.rsp.req_lim_delta,

			   &hostdata->request_limit);



	del_timer(&evt_struct->timer);



	if (evt_struct->done)

		evt_struct->done(evt_struct);

	else
@@ -1313,7 +1388,7 @@ static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata, 
	}



	init_completion(&evt_struct->comp);

	rc = ibmvscsi_send_srp_event(evt_struct, hostdata);

	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);

	if (rc == 0)

		wait_for_completion(&evt_struct->comp);

	dma_unmap_single(hostdata->dev, addr, length, DMA_BIDIRECTIONAL);
@@ -1504,6 +1579,7 @@ static struct scsi_host_template driver_template = { 
	.queuecommand = ibmvscsi_queuecommand,

	.eh_abort_handler = ibmvscsi_eh_abort_handler,

	.eh_device_reset_handler = ibmvscsi_eh_device_reset_handler,

	.eh_host_reset_handler = ibmvscsi_eh_host_reset_handler,

	.slave_configure = ibmvscsi_slave_configure,

	.change_queue_depth = ibmvscsi_change_queue_depth,

	.cmd_per_lun = 16,

drivers/scsi/ibmvscsi/ibmvscsi.h

+1 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ struct srp_event_struct { 
	union viosrp_iu iu;

	void (*cmnd_done) (struct scsi_cmnd *);

	struct completion comp;

	struct timer_list timer;

	union viosrp_iu *sync_srp;

	struct srp_direct_buf *ext_list;

	dma_addr_t ext_list_token;