LU-17048 mdd: protect layout change in MDD layer

[fs/lustre-release.git] / lustre / mdd / mdd_internal.h

diff --git a/lustre/mdd/mdd_internal.h b/lustre/mdd/mdd_internal.h
index 7ba9f35..e8e00f3 100644 (file)
--- a/lustre/mdd/mdd_internal.h
+++ b/lustre/mdd/mdd_internal.h
@@ -894,4 +894,45 @@ bool mdd_changelog_is_space_safe(const struct lu_env *env,
                                 struct llog_handle *lgh,
                                 bool estimate);
 
+#define MAX_TRANS_RETRIED 20
+
+static inline int
+mdd_write_lock_two_objects(const struct lu_env *env,
+                          struct mdd_object *obj1,
+                          struct mdd_object *obj2)
+{
+       int order;
+
+       /* there shouldn't be callers with obj1 == NULL */
+       LASSERT(obj1 != NULL);
+       if (!obj2)
+               goto out_lock1;
+
+       order = lu_fid_cmp(mdd_object_fid(obj1), mdd_object_fid(obj2));
+       if (unlikely(order == 0))
+               return -EPERM;
+
+       if (order > 0) {
+               mdd_write_lock(env, obj1, DT_TGT_CHILD);
+               mdd_write_lock(env, obj2, DT_TGT_CHILD);
+       } else {
+               mdd_write_lock(env, obj2, DT_TGT_CHILD);
+out_lock1:
+               mdd_write_lock(env, obj1, DT_TGT_CHILD);
+       }
+
+       return 0;
+}
+
+static inline void
+mdd_write_unlock_two_objects(const struct lu_env *env,
+                            struct mdd_object *obj1,
+                            struct mdd_object *obj2)
+{
+       mdd_write_unlock(env, obj1);
+       if (obj2)
+               mdd_write_unlock(env, obj2);
+}
+
+
 #endif