[Ocfs2-devel] [PATCH 1/1] OCFS2: don't leave free'd mle attached to hb events

[wengang wang]

don't leave free'd mle attached to hb events.
    
in dlm_add_migration_mle() the mle is attched to "heartbeat events" anyway no
matter there is an existing mle with same name(returns -EEXIST).
dlm_migrate_lockres() calls dlm_add_migration_mle(). in case the later function
returning -EEXIST, dlm_migrate_lockres() frees the (new) mle without detaching
it from "hb events". so that later "hb events" related operations could improperly
operate against wrong mle objects or against an invalid memory address.

the patch fixes above problem. it marks the mle as "added" just after
dlm_add_migration_mle() is called.

Signed-off-by: Wengang Wang <wen.gang.wang at oracle.com>

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 83bcaf2..0df80e9 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2498,11 +2498,12 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm,
 	spin_unlock(&dlm->master_lock);
 	spin_unlock(&dlm->spinlock);
 
+	mle_added = 1;
+
 	if (ret == -EEXIST) {
 		mlog(0, "another process is already migrating it\n");
 		goto fail;
 	}
-	mle_added = 1;
 
 	/*
 	 * set the MIGRATING flag and flush asts