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authorSteffen Maier <maier@linux.vnet.ibm.com>2012-09-04 15:23:32 +0200
committerJames Bottomley <JBottomley@Parallels.com>2012-09-24 12:11:01 +0400
commitcb45214960bc989af8b911ebd77da541c797717d (patch)
treec6d934378945076e699eeeea5880a452cbf53552 /drivers/s390/scsi/zfcp_ccw.c
parent01e60527f0a49b3d7df603010bd6079bb4b6cf07 (diff)
[SCSI] zfcp: Do not wakeup while suspended
If the mapping of FCP device bus ID and corresponding subchannel is modified while the Linux image is suspended, the resume of FCP devices can fail. During resume, zfcp gets callbacks from cio regarding the modified subchannels but they can be arbitrarily mixed with the restore/resume callback. Since the cio callbacks would trigger adapter recovery, zfcp could wakeup before the resume callback. Therefore, ignore the cio callbacks regarding subchannels while being suspended. We can safely do so, since zfcp does not deal itself with subchannels. For problem determination purposes, we still trace the ignored callback events. The following kernel messages could be seen on resume: kernel: <WWPN>: parent <FCP device bus ID> should not be sleeping As part of adapter reopen recovery, zfcp performs auto port scanning which can erroneously try to register new remote ports with scsi_transport_fc and the device core code complains about the parent (adapter) still sleeping. kernel: zfcp.3dff9c: <FCP device bus ID>:\ Setting up the QDIO connection to the FCP adapter failed <last kernel message repeated 3 more times> kernel: zfcp.574d43: <FCP device bus ID>:\ ERP cannot recover an error on the FCP device In such cases, the adapter gave up recovery and remained blocked along with its child objects: remote ports and LUNs/scsi devices. Even the adapter shutdown as part of giving up recovery failed because the ccw device state remained disconnected. Later, the corresponding remote ports ran into dev_loss_tmo. As a result, the LUNs were erroneously not available again after resume. Even a manually triggered adapter recovery (e.g. sysfs attribute failed, or device offline/online via sysfs) could not recover the adapter due to the remaining disconnected state of the corresponding ccw device. Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> #2.6.32+ Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/s390/scsi/zfcp_ccw.c')
-rw-r--r--drivers/s390/scsi/zfcp_ccw.c73
1 files changed, 63 insertions, 10 deletions
diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c
index e37f0455194..9646766360d 100644
--- a/drivers/s390/scsi/zfcp_ccw.c
+++ b/drivers/s390/scsi/zfcp_ccw.c
@@ -39,17 +39,23 @@ void zfcp_ccw_adapter_put(struct zfcp_adapter *adapter)
spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
}
-static int zfcp_ccw_activate(struct ccw_device *cdev)
-
+/**
+ * zfcp_ccw_activate - activate adapter and wait for it to finish
+ * @cdev: pointer to belonging ccw device
+ * @clear: Status flags to clear.
+ * @tag: s390dbf trace record tag
+ */
+static int zfcp_ccw_activate(struct ccw_device *cdev, int clear, char *tag)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 0;
+ zfcp_erp_clear_adapter_status(adapter, clear);
zfcp_erp_set_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING);
zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
- "ccresu2");
+ tag);
zfcp_erp_wait(adapter);
flush_work(&adapter->scan_work);
@@ -164,26 +170,29 @@ static int zfcp_ccw_set_online(struct ccw_device *cdev)
BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
adapter->req_no = 0;
- zfcp_ccw_activate(cdev);
+ zfcp_ccw_activate(cdev, 0, "ccsonl1");
zfcp_ccw_adapter_put(adapter);
return 0;
}
/**
- * zfcp_ccw_set_offline - set_offline function of zfcp driver
+ * zfcp_ccw_offline_sync - shut down adapter and wait for it to finish
* @cdev: pointer to belonging ccw device
+ * @set: Status flags to set.
+ * @tag: s390dbf trace record tag
*
* This function gets called by the common i/o layer and sets an adapter
* into state offline.
*/
-static int zfcp_ccw_set_offline(struct ccw_device *cdev)
+static int zfcp_ccw_offline_sync(struct ccw_device *cdev, int set, char *tag)
{
struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
if (!adapter)
return 0;
- zfcp_erp_adapter_shutdown(adapter, 0, "ccsoff1");
+ zfcp_erp_set_adapter_status(adapter, set);
+ zfcp_erp_adapter_shutdown(adapter, 0, tag);
zfcp_erp_wait(adapter);
zfcp_ccw_adapter_put(adapter);
@@ -191,6 +200,18 @@ static int zfcp_ccw_set_offline(struct ccw_device *cdev)
}
/**
+ * zfcp_ccw_set_offline - set_offline function of zfcp driver
+ * @cdev: pointer to belonging ccw device
+ *
+ * This function gets called by the common i/o layer and sets an adapter
+ * into state offline.
+ */
+static int zfcp_ccw_set_offline(struct ccw_device *cdev)
+{
+ return zfcp_ccw_offline_sync(cdev, 0, "ccsoff1");
+}
+
+/**
* zfcp_ccw_notify - ccw notify function
* @cdev: pointer to belonging ccw device
* @event: indicates if adapter was detached or attached
@@ -207,6 +228,11 @@ static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
switch (event) {
case CIO_GONE:
+ if (atomic_read(&adapter->status) &
+ ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
+ zfcp_dbf_hba_basic("ccnigo1", adapter);
+ break;
+ }
dev_warn(&cdev->dev, "The FCP device has been detached\n");
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1");
break;
@@ -216,6 +242,11 @@ static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2");
break;
case CIO_OPER:
+ if (atomic_read(&adapter->status) &
+ ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
+ zfcp_dbf_hba_basic("ccniop1", adapter);
+ break;
+ }
dev_info(&cdev->dev, "The FCP device is operational again\n");
zfcp_erp_set_adapter_status(adapter,
ZFCP_STATUS_COMMON_RUNNING);
@@ -251,6 +282,28 @@ static void zfcp_ccw_shutdown(struct ccw_device *cdev)
zfcp_ccw_adapter_put(adapter);
}
+static int zfcp_ccw_suspend(struct ccw_device *cdev)
+{
+ zfcp_ccw_offline_sync(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccsusp1");
+ return 0;
+}
+
+static int zfcp_ccw_thaw(struct ccw_device *cdev)
+{
+ /* trace records for thaw and final shutdown during suspend
+ can only be found in system dump until the end of suspend
+ but not after resume because it's based on the memory image
+ right after the very first suspend (freeze) callback */
+ zfcp_ccw_activate(cdev, 0, "ccthaw1");
+ return 0;
+}
+
+static int zfcp_ccw_resume(struct ccw_device *cdev)
+{
+ zfcp_ccw_activate(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccresu1");
+ return 0;
+}
+
struct ccw_driver zfcp_ccw_driver = {
.driver = {
.owner = THIS_MODULE,
@@ -263,7 +316,7 @@ struct ccw_driver zfcp_ccw_driver = {
.set_offline = zfcp_ccw_set_offline,
.notify = zfcp_ccw_notify,
.shutdown = zfcp_ccw_shutdown,
- .freeze = zfcp_ccw_set_offline,
- .thaw = zfcp_ccw_activate,
- .restore = zfcp_ccw_activate,
+ .freeze = zfcp_ccw_suspend,
+ .thaw = zfcp_ccw_thaw,
+ .restore = zfcp_ccw_resume,
};