[Ocfs2-devel] [PATCH] ocfs2: oldmle should be put while -EEXIST returned, and the new mle should not be get once at that time.

From: Guozhonghua <guozhonghua@h3c.com>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [PATCH] ocfs2: oldmle should be put while -EEXIST returned, and the new mle should not be get once at that time.
Date: Wed, 14 Sep 2016 02:30:44 +0000	[thread overview]
Message-ID: <71604351584F6A4EBAE558C676F37CA4A3D35566@H3CMLB12-EX.srv.huawei-3com.com> (raw)


In the function dlm_migrate_lockres, while calling dlm_add_migration_mle, and the ret is --EEXIST.
At this time, the oldmle should be put one time for it had been get once in dlm_find_mle.
And the new mle should not get once for it had not been initialized before goto fail.

Signed-off-by: Guozhonghua <guozhonghua@h3c.com>

--- ocfs2.orig/dlm/dlmmaster.c  2016-09-13 15:18:13.602684325 +0800
+++ ocfs2/dlm/dlmmaster.c       2016-09-14 10:15:10.496873879 +0800
@@ -2573,8 +2573,6 @@ static int dlm_is_lockres_migrateable(st
 /*
  * DLM_MIGRATE_LOCKRES
  */
-
-
 static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
                               struct dlm_lock_resource *res, u8 target)
 {
@@ -2621,20 +2619,26 @@ static int dlm_migrate_lockres(struct dl
        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.
         */
        dlm_get_mle_inuse(mle);
+       mle_added = 1;
+
        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;
-
        /*
         * set the MIGRATING flag and flush asts
         * if we fail after this we need to re-dirty the lockres

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