The prior version of this patch introduced a problem for the error
handler routines. Calling ibmvscsi_eh_reset_device during a
initialization/login would result in the reset failing without need.
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.
By setting the request_limit in send_srp_login to 1 we allowed login
requests to be sent to the server adapter. If this was not an initial
login, but was a login after a disconnect with the server, other I/O
requests could attempt to be processed before the login occured.
To address this we can set the request_limit to 0 while doing the login
and add an exception where login requests, along with task management
events, are always passed to the server.
There is a case where the request_limit had already reached 0 would
result
in all events being sent rather than returning SCSI_MLQUEUE_HOST_BUSY;
this
has also been fixed by this patch.
Signed-off-by: Robert Jennings <rcj@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Brian King <brking@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/ibmvscsi/ibmvscsi.c | 59 ++++++++++++++++++++++++++++++++-------
1 file changed, 48 insertions(+), 11 deletions(-)
Index: b/drivers/scsi/ibmvscsi/ibmvscsi.c
===================================================================
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -556,7 +556,7 @@ static int ibmvscsi_send_srp_event(struc
unsigned long timeout)
{
u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
- int request_status;
+ int request_status = 0;
int rc;
/* If we have exhausted our request limit, just fail this request,
@@ -574,6 +574,13 @@ static int ibmvscsi_send_srp_event(struc
if (request_status < -1)
goto send_error;
/* Otherwise, we may have run out of requests. */
+ /* If request limit was 0 when we started the adapter is in the
+ * process of performing a login with the server adapter, or
+ * we may have run out of requests.
+ */
+ else if (request_status == -1 &&
+ evt_struct->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
+ goto send_busy;
/* Abort and reset calls should make it through.
* Nothing except abort and reset should use the last two
* slots unless we had two or less to begin with.
@@ -633,7 +640,8 @@ static int ibmvscsi_send_srp_event(struc
unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
free_event_struct(&hostdata->pool, evt_struct);
- atomic_inc(&hostdata->request_limit);
+ if (request_status != -1)
+ atomic_inc(&hostdata->request_limit);
return SCSI_MLQUEUE_HOST_BUSY;
send_error:
@@ -927,10 +935,11 @@ static int send_srp_login(struct ibmvscs
login->req_buf_fmt = SRP_BUF_FORMAT_DIRECT | SRP_BUF_FORMAT_INDIRECT;
spin_lock_irqsave(hostdata->host->host_lock, flags);
- /* Start out with a request limit of 1, since this is negotiated in
- * the login request we are just sending
+ /* Start out with a request limit of 0, since this is negotiated in
+ * the login request we are just sending and login requests always
+ * get sent by the driver regardless of request_limit.
*/
- atomic_set(&hostdata->request_limit, 1);
+ atomic_set(&hostdata->request_limit, 0);
rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);
spin_unlock_irqrestore(hostdata->host->host_lock, flags);
@@ -967,6 +976,7 @@ static int ibmvscsi_eh_abort_handler(str
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
@@ -1010,15 +1020,30 @@ static int ibmvscsi_eh_abort_handler(str
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);
- spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+ wait_switch = jiffies + (init_timeout * HZ);
+ do {
+ 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));
+
if (rsp_rc != 0) {
+ free_event_struct(&found_evt->hostdata->pool, found_evt);
+ spin_unlock_irqrestore(hostdata->host->host_lock, flags);
sdev_printk(KERN_ERR, cmd->device,
"failed to send abort() event. rc=%d\n", rsp_rc);
return FAILED;
}
+ spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
wait_for_completion(&evt->comp);
/* make sure we got a good response */
@@ -1090,6 +1115,7 @@ static int ibmvscsi_eh_device_reset_hand
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);
evt = get_event_struct(&hostdata->pool);
@@ -1116,9 +1142,20 @@ static int ibmvscsi_eh_device_reset_hand
tsk_mgmt->lun);
evt->sync_srp = &srp_rsp;
- init_completion(&evt->comp);
- rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, init_timeout * 2);
- spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+ wait_switch = jiffies + (init_timeout * HZ);
+ do {
+ init_completion(&evt->comp);
+ rsp_rc = ibmvscsi_send_srp_event(evt, hostdata, init_timeout * 2);
+ spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+
+ if (rsp_rc != SCSI_MLQUEUE_HOST_BUSY)
+ break;
+
+ msleep(10);
+ spin_lock_irqsave(hostdata->host->host_lock, flags);
+ } while (time_before(jiffies, wait_switch));
+
if (rsp_rc != 0) {
sdev_printk(KERN_ERR, cmd->device,
"failed to send reset event. rc=%d\n", rsp_rc);
-
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