[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: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index c63a26e..0a16972 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -509,6 +509,70 @@
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 @@
* 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 @@
*/
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 @@
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 @@
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 @@
*/
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 @@
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 @@
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 @@
}
/**
- * 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)
+ * ibmvscsi_eh_host_reset_handler - Reset the connection to the server
+ * @cmd: struct scsi_cmnd having problems
+*/
+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 @@
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 @@
}
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 @@
.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,