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authorSteffen Maier <maier@linux.vnet.ibm.com>2012-09-04 15:23:35 +0200
committerJames Bottomley <JBottomley@Parallels.com>2012-09-24 12:11:02 +0400
commit43f60cbd56c4a3a8f7fb009ac52d6d57ac864921 (patch)
tree3161f846752fb4090b622319c2bf2015394eedba /drivers/s390/scsi/zfcp_fc.c
parentd99b601b63386f3395dc26a699ae703a273d9982 (diff)
[SCSI] zfcp: No automatic port_rescan on events
In FC fabrics with large zones, the automatic port_rescan on incoming ELS and any adapter recovery can cause quite some traffic at the very same time, especially if lots of Linux images share an HBA, which is common on s390. This can cause trouble and failures. Fix this by making such port rescans dependent on a user configurable module parameter. The following unconditional automatic port rescans remain as is: On setting an adapter online and on manual user-triggered writes to the sysfs attribute port_rescan. Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/s390/scsi/zfcp_fc.c')
-rw-r--r--drivers/s390/scsi/zfcp_fc.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 88688a80b2c1..ff598cd68b2d 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -26,6 +26,27 @@ static u32 zfcp_fc_rscn_range_mask[] = {
[ELS_ADDR_FMT_FAB] = 0x000000,
};
+static bool no_auto_port_rescan;
+module_param_named(no_auto_port_rescan, no_auto_port_rescan, bool, 0600);
+MODULE_PARM_DESC(no_auto_port_rescan,
+ "no automatic port_rescan (default off)");
+
+void zfcp_fc_conditional_port_scan(struct zfcp_adapter *adapter)
+{
+ if (no_auto_port_rescan)
+ return;
+
+ queue_work(adapter->work_queue, &adapter->scan_work);
+}
+
+void zfcp_fc_inverse_conditional_port_scan(struct zfcp_adapter *adapter)
+{
+ if (!no_auto_port_rescan)
+ return;
+
+ queue_work(adapter->work_queue, &adapter->scan_work);
+}
+
/**
* zfcp_fc_post_event - post event to userspace via fc_transport
* @work: work struct with enqueued events
@@ -206,7 +227,7 @@ static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req)
zfcp_fc_enqueue_event(fsf_req->adapter, FCH_EVT_RSCN,
*(u32 *)page);
}
- queue_work(fsf_req->adapter->work_queue, &fsf_req->adapter->scan_work);
+ zfcp_fc_conditional_port_scan(fsf_req->adapter);
}
static void zfcp_fc_incoming_wwpn(struct zfcp_fsf_req *req, u64 wwpn)