[Ocfs2-devel] MLE process bugs and its patch for review.

[Guozhonghua]

Hi, All

In the function dlm_migrate_lockres, as the return value is -EEXIST, the mle should not be added because it had not been initialized. And the oldmle should be put.
Same as in function dlm_migrate_request_handler, when the return val is -EEIST, the mle should cache freed, otherwise memory lead may be occurred.


*** ocfs2.org/dlm/dlmmaster.c   2016-09-01 15:46:16.163140295 +0800
--- ocfs2/dlm/dlmmaster.c       2016-09-01 18:56:21.211442107 +0800
*************** static int dlm_is_lockres_migrateable(st
*** 2592,2599 ****
  /*
   * DLM_MIGRATE_LOCKRES
   */
-
-
  static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
                               struct dlm_lock_resource *res, u8 target)
  {
--- 2592,2597 ----
*************** static int dlm_migrate_lockres(struct dl
*** 2640,2645 ****
--- 2638,2654 ----
        spin_lock(&dlm->master_lock);
        ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name,
                                    namelen, target, dlm->node_num);
+
+       if (ret == -EEXIST) {
+               if(oldmle)
+                       dlm_put_mle(oldmle);
+
+               spin_unlock(&dlm->master_lock);
+               spin_unlock(&dlm->spinlock);
+               mlog(0, "another process is already migrating it\n");
+               goto fail;
+       }
+
        /* get an extra reference on the mle.
         * otherwise the assert_master from the new
         * master will destroy this.
*************** static int dlm_migrate_lockres(struct dl
*** 2648,2657 ****
        spin_unlock(&dlm->master_lock);
        spin_unlock(&dlm->spinlock);

-       if (ret == -EEXIST) {
-               mlog(0, "another process is already migrating it\n");
-               goto fail;
-       }
        mle_added = 1;

        /*
--- 2657,2662 ----
*************** int dlm_migrate_request_handler(struct o
*** 3206,3211 ****
--- 3211,3218 ----
                                    name, namelen,
                                    migrate->new_master,
                                    migrate->master);
+       if (ret < 0)
+               kmem_cache_free(dlm_mle_cache, mle);

        spin_unlock(&dlm->master_lock);
  unlock:
-------------------------------------------------------------------------------------------------------------------------------------
本邮件及其附件含有杭州华三通信技术有限公司的保密信息，仅限于发送给上面地址中列出
的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、
或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本
邮件！
This e-mail and its attachments contain confidential information from H3C, which is
intended only for the person or entity whose address is listed above. Any use of the
information contained herein in any way (including, but not limited to, total or partial
disclosure, reproduction, or dissemination) by persons other than the intended
recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender
by phone or email immediately and delete it!