[PATCH] ocfs2: recheck recovery state after getting lock

* after successfully taking the $RECOVERY lock in EX mode, recheck to make
  sure that recovery has not already begun or completed on another node

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 186e9a76aa58..f9ce864966ec 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -2032,6 +2032,30 @@ again:
                              dlm->reco.new_master);
                         status = -EEXIST;
                 } else {
+                        status = 0;
+
+                        /* see if recovery was already finished elsewhere */
+                        spin_lock(&dlm->spinlock);
+                        if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
+                                status = -EINVAL;       
+                                mlog(0, "%s: got reco EX lock, but "
+                                     "node got recovered already\n", dlm->name);
+                                if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
+                                        mlog(ML_ERROR, "%s: new master is %u "
+                                             "but no dead node!\n", 
+                                             dlm->name, dlm->reco.new_master);
+                                        BUG();
+                                }
+                        }
+                        spin_unlock(&dlm->spinlock);
+                }
+
+                /* if this node has actually become the recovery master,
+                 * set the master and send the messages to begin recovery */
+                if (!status) {
+                        mlog(0, "%s: dead=%u, this=%u, sending "
+                             "begin_reco now\n", dlm->name, 
+                             dlm->reco.dead_node, dlm->node_num);
                         status = dlm_send_begin_reco_message(dlm,
                                       dlm->reco.dead_node);
                         /* this always succeeds */