[SCSI] libfc: add interface to allocate a sequence for incoming requests

For incoming ELS and FCP requests, we often don't require an
exchange and sequence, however, sometimes we do.  For those cases,
(primarily FCP requests for targets) add a function to set up
the exchange and sequence.

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, 25 insertions, 0 deletions

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 61eabd3ce436..027042a6de3b 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -1231,6 +1231,28 @@ free:
 }
 
 /**
+ * fc_seq_assign() - Assign exchange and sequence for incoming request
+ * @lport: The local port that received the request
+ * @fp:    The request frame
+ *
+ * On success, the sequence pointer will be returned and also in fr_seq(@fp).
+ */
+static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
+{
+        struct fc_exch_mgr_anchor *ema;
+
+        WARN_ON(lport != fr_dev(fp));
+        WARN_ON(fr_seq(fp));
+        fr_seq(fp) = NULL;
+
+        list_for_each_entry(ema, &lport->ema_list, ema_list)
+                if ((!ema->match || ema->match(fp)) &&
+                    fc_seq_lookup_recip(lport, ema->mp, fp) != FC_RJT_NONE)
+                        break;
+        return fr_seq(fp);
+}
+
+/**
  * fc_exch_recv_req() - Handler for an incoming request where is other
  *                      end is originating the sequence
  * @lport: The local port that received the request
@@ -2283,6 +2305,9 @@ int fc_exch_init(struct fc_lport *lport)
         if (!lport->tt.seq_exch_abort)
                 lport->tt.seq_exch_abort = fc_seq_exch_abort;
 
+        if (!lport->tt.seq_assign)
+                lport->tt.seq_assign = fc_seq_assign;
+
         return 0;
 }
 EXPORT_SYMBOL(fc_exch_init);