scsi: iscsi: Add iscsi_cls_conn refcount helpers

There are a couple places where we could free the iscsi_cls_conn while it's
still in use. This adds some helpers to get/put a refcount on the struct
and converts an exiting user. Subsequent commits will then use the helpers
to fix 2 bugs in the eh code.

Link: https://lore.kernel.org/r/20210525181821.7617-11-michael.christie@oracle.com
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 2aaf836786548bea9c2955b84b6e554dd5fb7d10..ab39d7f65bbb09fd567675ecb2d6a0c3ce5b8492 100644 (file)
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1361,7 +1361,6 @@ void iscsi_session_failure(struct iscsi_session *session,
                           enum iscsi_err err)
 {
        struct iscsi_conn *conn;
-       struct device *dev;
 
        spin_lock_bh(&session->frwd_lock);
        conn = session->leadconn;
@@ -1370,10 +1369,8 @@ void iscsi_session_failure(struct iscsi_session *session,
                return;
        }
 
-       dev = get_device(&conn->cls_conn->dev);
+       iscsi_get_conn(conn->cls_conn);
        spin_unlock_bh(&session->frwd_lock);
-       if (!dev)
-               return;
        /*
         * if the host is being removed bypass the connection
         * recovery initialization because we are going to kill
@@ -1383,7 +1380,7 @@ void iscsi_session_failure(struct iscsi_session *session,
                iscsi_conn_error_event(conn->cls_conn, err);
        else
                iscsi_conn_failure(conn, err);
-       put_device(dev);
+       iscsi_put_conn(conn->cls_conn);
 }
 EXPORT_SYMBOL_GPL(iscsi_session_failure);
 

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index b8a93e6078914282a492790c63250e557aefefb8..909134b9c3137dae59af81b992e0d6f3e52329a0 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2457,6 +2457,18 @@ int iscsi_destroy_conn(struct iscsi_cls_conn *conn)
 }
 EXPORT_SYMBOL_GPL(iscsi_destroy_conn);
 
+void iscsi_put_conn(struct iscsi_cls_conn *conn)
+{
+       put_device(&conn->dev);
+}
+EXPORT_SYMBOL_GPL(iscsi_put_conn);
+
+void iscsi_get_conn(struct iscsi_cls_conn *conn)
+{
+       get_device(&conn->dev);
+}
+EXPORT_SYMBOL_GPL(iscsi_get_conn);
+
 /*
  * iscsi interface functions
  */

diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 3974329d4d0233aa147566c8ade19edf473dee28..c5d7810fd7926a9cb3e51f1ab9344d7ea76e7f2e 100644 (file)
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -443,6 +443,8 @@ extern void iscsi_remove_session(struct iscsi_cls_session *session);
 extern void iscsi_free_session(struct iscsi_cls_session *session);
 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
                                                int dd_size, uint32_t cid);
+extern void iscsi_put_conn(struct iscsi_cls_conn *conn);
+extern void iscsi_get_conn(struct iscsi_cls_conn *conn);
 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 extern void iscsi_block_session(struct iscsi_cls_session *session);