[SCSI] fix for fc transport recursion problem.

In the scenario that a link was broken, the devloss timer for each
rport was expire at roughly the same time, causing lots of "delete"
workqueue items being queued. Depth is dependent upon the number of
rports that were on the link.

The rport target remove calls were calling flush_scheduled_work(),
which would interrupt the stream, and start the next workqueue item,
which did the same thing, and so on until recursion depth was large.

This fix stops the recursion in the initial delete path, and pushes it
off to a host-level work item that reaps the dead rports.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
index fac547d32a98..394f14a5b7cb 100644
--- a/include/scsi/scsi_transport_fc.h
+++ b/include/scsi/scsi_transport_fc.h
@@ -79,6 +79,7 @@ enum fc_port_state {
         FC_PORTSTATE_LINKDOWN,
         FC_PORTSTATE_ERROR,
         FC_PORTSTATE_LOOPBACK,
+        FC_PORTSTATE_DELETED,
 };
 
 
@@ -325,8 +326,14 @@ struct fc_host_attrs {
         struct list_head rport_bindings;
         u32 next_rport_number;
         u32 next_target_id;
+        u8 flags;
+        struct work_struct rport_del_work;
 };
 
+/* values for struct fc_host_attrs "flags" field: */
+#define FC_SHOST_RPORT_DEL_SCHEDULED    0x01
+
+
 #define fc_host_node_name(x) \
         (((struct fc_host_attrs *)(x)->shost_data)->node_name)
 #define fc_host_port_name(x)    \
@@ -365,6 +372,10 @@ struct fc_host_attrs {
         (((struct fc_host_attrs *)(x)->shost_data)->next_rport_number)
 #define fc_host_next_target_id(x) \
         (((struct fc_host_attrs *)(x)->shost_data)->next_target_id)
+#define fc_host_flags(x) \
+        (((struct fc_host_attrs *)(x)->shost_data)->flags)
+#define fc_host_rport_del_work(x) \
+        (((struct fc_host_attrs *)(x)->shost_data)->rport_del_work)
 
 
 /* The functions by which the transport class and the driver communicate */