LU-6875 update: set st to NULL in error handler

In thandle_get_sub_by_dt, if create sub thandle fails,
it should reset st to NULL, otherwise st, whose value
is ERR_PTR(rc), might be freeed incorrectly in the
following error handler path.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I7262593fa5aa6bc3f0ed418aaa5637e84077088b
Reviewed-on: http://review.whamcloud.com/15691
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/target/update_trans.c b/lustre/target/update_trans.c
index 7a3243b..00bc034 100644 (file)
--- a/lustre/target/update_trans.c
+++ b/lustre/target/update_trans.c
@@ -1123,6 +1123,7 @@ struct thandle *thandle_get_sub_by_dt(const struct lu_env *env,
                                      struct dt_device *sub_dt)
 {
        struct sub_thandle      *st = NULL;
+       struct sub_thandle      *master_st = NULL;
        struct top_thandle      *top_th;
        struct thandle          *sub_th = NULL;
        int                     rc = 0;
@@ -1156,19 +1157,29 @@ struct thandle *thandle_get_sub_by_dt(const struct lu_env *env,
                /* Add master sub th to the top trans list */
                tmt->tmt_master_sub_dt =
                        top_th->tt_master_sub_thandle->th_dev;
-               st = create_sub_thandle_with_thandle(top_th,
-                               top_th->tt_master_sub_thandle);
-               if (IS_ERR(st))
-                       GOTO(stop_trans, rc = PTR_ERR(st));
+               master_st = create_sub_thandle_with_thandle(top_th,
+                                       top_th->tt_master_sub_thandle);
+               if (IS_ERR(master_st)) {
+                       rc = PTR_ERR(master_st);
+                       master_st = NULL;
+                       GOTO(stop_trans, rc);
+               }
        }
 
        /* create and init sub th to the top trans list */
        st = create_sub_thandle_with_thandle(top_th, sub_th);
+       if (IS_ERR(st)) {
+               rc = PTR_ERR(st);
+               st = NULL;
+               GOTO(stop_trans, rc);
+       }
        st->st_sub_th->th_wait_submit = 1;
 stop_trans:
        if (rc < 0) {
-               if (st != NULL)
-                       OBD_FREE_PTR(st);
+               if (master_st != NULL) {
+                       list_del(&master_st->st_sub_list);
+                       OBD_FREE_PTR(master_st);
+               }
                sub_th->th_result = rc;
                dt_trans_stop(env, sub_dt, sub_th);
                sub_th = ERR_PTR(rc);