2 files changed, 50 insertions, 11 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index f5915d4d63d9..efceed451b46 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1056,7 +1056,9 @@ static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
         ctask->mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
                                             NULL, 0);
         if (!ctask->mtask) {
+                spin_unlock_bh(&session->lock);
                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+                spin_lock_bh(&session->lock)
                 debug_scsi("abort sent failure [itt 0x%x]\n", ctask->itt);
                 return -EPERM;
         }
@@ -1073,6 +1075,7 @@ static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
                 debug_scsi("abort set timeout [itt 0x%x]\n", ctask->itt);
         }
         spin_unlock_bh(&session->lock);
+        mutex_unlock(&session->eh_mutex);
         scsi_queue_work(session->host, &conn->xmitwork);
 
         /*
@@ -1090,6 +1093,7 @@ static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
         if (signal_pending(current))
                 flush_signals(current);
         del_timer_sync(&conn->tmabort_timer);
+        mutex_lock(&session->eh_mutex);
         spin_lock_bh(&session->lock);
         return 0;
 }
@@ -1165,31 +1169,45 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         __iscsi_put_ctask(ctask);
 }
 
+static void iscsi_suspend_tx(struct iscsi_conn *conn)
+{
+        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+        scsi_flush_work(conn->session->host);
+}
+
+static void iscsi_start_tx(struct iscsi_conn *conn)
+{
+        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+        scsi_queue_work(conn->session->host, &conn->xmitwork);
+}
+
 int iscsi_eh_abort(struct scsi_cmnd *sc)
 {
+        struct Scsi_Host *host = sc->device->host;
+        struct iscsi_session *session = iscsi_hostdata(host->hostdata);
         struct iscsi_cmd_task *ctask;
         struct iscsi_conn *conn;
-        struct iscsi_session *session;
         int rc;
 
+        mutex_lock(&session->eh_mutex);
+        spin_lock_bh(&session->lock);
         /*
          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
          * got the command.
          */
         if (!sc->SCp.ptr) {
                 debug_scsi("sc never reached iscsi layer or it completed.\n");
+                spin_unlock_bh(&session->lock);
+                mutex_unlock(&session->eh_mutex);
                 return SUCCESS;
         }
 
         ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
         conn = ctask->conn;
-        session = conn->session;
 
         conn->eh_abort_cnt++;
         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
 
-        spin_lock_bh(&session->lock);
-
         /*
          * If we are not logged in or we have started a new session
          * then let the host reset code handle this
@@ -1226,6 +1244,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
         switch (conn->tmabort_state) {
         case TMABORT_SUCCESS:
                 spin_unlock_bh(&session->lock);
+                iscsi_suspend_tx(conn);
                 /*
                  * clean up task if aborted. grab the recv lock as a writer
                  */
@@ -1234,11 +1253,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
                 fail_command(conn, ctask, DID_ABORT << 16);
                 spin_unlock(&session->lock);
                 write_unlock_bh(conn->recv_lock);
-                /*
-                 * make sure xmit thread is not still touching the
-                 * ctask/scsi_cmnd
-                 */
-                scsi_flush_work(session->host);
+                iscsi_start_tx(conn);
                 goto success_unlocked;
         case TMABORT_NOT_FOUND:
                 if (!ctask->sc) {
@@ -1258,12 +1273,14 @@ success:
         spin_unlock_bh(&session->lock);
 success_unlocked:
         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
+        mutex_unlock(&session->eh_mutex);
         return SUCCESS;
 
 failed:
         spin_unlock_bh(&session->lock);
 failed_unlocked:
         debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
+        mutex_unlock(&session->eh_mutex);
         return FAILED;
 }
 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
@@ -1410,6 +1427,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit,
         session->max_cmdsn = initial_cmdsn + 1;
         session->max_r2t = 1;
         session->tt = iscsit;
+        mutex_init(&session->eh_mutex);
 
         /* initialize SCSI PDU commands pool */
         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
@@ -1743,9 +1761,22 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
 {
         int old_stop_stage;
 
+        mutex_lock(&session->eh_mutex);
         spin_lock_bh(&session->lock);
         if (conn->stop_stage == STOP_CONN_TERM) {
                 spin_unlock_bh(&session->lock);
+                mutex_unlock(&session->eh_mutex);
+                return;
+        }
+
+        /*
+         * The LLD either freed/unset the lock on us, or userspace called
+         * stop but did not create a proper connection (connection was never
+         * bound or it was unbound then stop was called).
+         */
+        if (!conn->recv_lock) {
+                spin_unlock_bh(&session->lock);
+                mutex_unlock(&session->eh_mutex);
                 return;
         }
 
@@ -1762,9 +1793,9 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
         old_stop_stage = conn->stop_stage;
         conn->stop_stage = flag;
         conn->c_stage = ISCSI_CONN_STOPPED;
-        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
         spin_unlock_bh(&session->lock);
-        scsi_flush_work(session->host);
+
+        iscsi_suspend_tx(conn);
 
         write_lock_bh(conn->recv_lock);
         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
@@ -1793,6 +1824,7 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
         fail_all_commands(conn);
         flush_control_queues(session, conn);
         spin_unlock_bh(&session->lock);
+        mutex_unlock(&session->eh_mutex);
 }
 
 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 007d442412e2..b4b31132618b 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -205,6 +205,13 @@ struct iscsi_queue {
 };
 
 struct iscsi_session {
+        /*
+         * Syncs up the scsi eh thread with the iscsi eh thread when sending
+         * task management functions. This must be taken before the session
+         * and recv lock.
+         */
+        struct mutex            eh_mutex;
+
         /* iSCSI session-wide sequencing */
         uint32_t                cmdsn;
         uint32_t                exp_cmdsn;