libfc: Avoid that sending after an abort triggers a kernel warning

Calling fc_seq_send() after an ABTS message has been received triggers
a kernel warning (WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT))). Avoid
this by returning -ENXIO to the caller if fc_seq_send() is invoked after
an ABTS message has been received.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

1 files changed, 37 insertions, 22 deletions

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index bc0aba4fabb4..2a7fd5afecca 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -463,15 +463,21 @@ static void fc_exch_delete(struct fc_exch *ep)
 }
 
 static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
-                       struct fc_frame *fp)
+                              struct fc_frame *fp)
 {
         struct fc_exch *ep;
         struct fc_frame_header *fh = fc_frame_header_get(fp);
-        int error;
+        int error = -ENXIO;
         u32 f_ctl;
         u8 fh_type = fh->fh_type;
 
         ep = fc_seq_exch(sp);
+
+        if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
+                fc_frame_free(fp);
+                goto out;
+        }
+
         WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));
 
         f_ctl = ntoh24(fh->fh_f_ctl);
@@ -514,6 +520,9 @@ out:
  * @lport: The local port that the exchange will be sent on
  * @sp:    The sequence to be sent
  * @fp:    The frame to be sent on the exchange
+ *
+ * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
+ * or indirectly by calling libfc_function_template.frame_send().
  */
 static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp,
                        struct fc_frame *fp)
@@ -621,27 +630,31 @@ static int fc_exch_abort_locked(struct fc_exch *ep,
         if (!sp)
                 return -ENOMEM;
 
-        ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
         if (timer_msec)
                 fc_exch_timer_set_locked(ep, timer_msec);
 
-        /*
-         * If not logged into the fabric, don't send ABTS but leave
-         * sequence active until next timeout.
-         */
-        if (!ep->sid)
-                return 0;
-
-        /*
-         * Send an abort for the sequence that timed out.
-         */
-        fp = fc_frame_alloc(ep->lp, 0);
-        if (fp) {
-                fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
-                               FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
-                error = fc_seq_send_locked(ep->lp, sp, fp);
-        } else
-                error = -ENOBUFS;
+        if (ep->sid) {
+                /*
+                 * Send an abort for the sequence that timed out.
+                 */
+                fp = fc_frame_alloc(ep->lp, 0);
+                if (fp) {
+                        ep->esb_stat |= ESB_ST_SEQ_INIT;
+                        fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
+                                       FC_TYPE_BLS, FC_FC_END_SEQ |
+                                       FC_FC_SEQ_INIT, 0);
+                        error = fc_seq_send_locked(ep->lp, sp, fp);
+                } else {
+                        error = -ENOBUFS;
+                }
+        } else {
+                /*
+                 * If not logged into the fabric, don't send ABTS but leave
+                 * sequence active until next timeout.
+                 */
+                error = 0;
+        }
+        ep->esb_stat |= ESB_ST_ABNORMAL;
         return error;
 }
 
@@ -1299,9 +1312,10 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
                 spin_unlock_bh(&ep->ex_lock);
                 goto reject;
         }
-        if (!(ep->esb_stat & ESB_ST_REC_QUAL))
+        if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
+                ep->esb_stat |= ESB_ST_REC_QUAL;
                 fc_exch_hold(ep);               /* hold for REC_QUAL */
-        ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
+        }
         fc_exch_timer_set_locked(ep, ep->r_a_tov);
 
         fp = fc_frame_alloc(ep->lp, sizeof(*ap));
@@ -1322,6 +1336,7 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
         }
         sp = fc_seq_start_next_locked(sp);
         fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
+        ep->esb_stat |= ESB_ST_ABNORMAL;
         spin_unlock_bh(&ep->ex_lock);
         fc_frame_free(rx_fp);
         return;