[SCSI] libfc: convert rport lookup to be RCU safe

To allow LLD to do lookups on rports without grabbing a mutex,
make them RCU-safe.  The caller of lport->tt.rport_lookup will
have the choice of holding disc_mutex or the rcu_read_lock().

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index 6d78df77dab6..b0310b9b3469 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -195,6 +195,7 @@ struct fc_rport_libfc_priv {
  * @rp_mutex:       The mutex that protects the remote port
  * @retry_work:     Handle for retries
  * @event_callback: Callback when READY, FAILED or LOGO states complete
+ * @rcu:            Structure used for freeing in an RCU-safe manner
  */
 struct fc_rport_priv {
         struct fc_lport             *local_port;
@@ -217,6 +218,7 @@ struct fc_rport_priv {
         struct list_head            peers;
         struct work_struct          event_work;
         u32                         supported_classes;
+        struct rcu_head             rcu;
 };
 
 /**