ocfs2: do not unconditionally purge the lockres in dlmlock_remote()

In dlmlock_remote(), do not call purge_lockres until the lock resource
actually changes. otherwise, the mastery info on the lockres will go away
underneath the caller.

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

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/ocfs2/dlm/dlmlock.c b/fs/ocfs2/dlm/dlmlock.c
index 57576208b79c..675123c30852 100644
--- a/fs/ocfs2/dlm/dlmlock.c
+++ b/fs/ocfs2/dlm/dlmlock.c
@@ -201,6 +201,7 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
                                       struct dlm_lock *lock, int flags)
 {
         enum dlm_status status = DLM_DENIED;
+        int lockres_changed = 1;
 
         mlog_entry("type=%d\n", lock->ml.type);
         mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
@@ -230,6 +231,10 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
                         dlm_error(status);
                 dlm_revert_pending_lock(res, lock);
                 dlm_lock_put(lock);
+                /* do NOT call calc_usage, as this would unhash the remote
+                 * lockres before we ever get to use it.  treat as if we
+                 * never made any change to the lockres. */
+                lockres_changed = 0;
         } else if (dlm_is_recovery_lock(res->lockname.name, 
                                         res->lockname.len)) {
                 /* special case for the $RECOVERY lock.
@@ -243,7 +248,8 @@ static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
         }
         spin_unlock(&res->spinlock);
 
-        dlm_lockres_calc_usage(dlm, res);
+        if (lockres_changed)
+                dlm_lockres_calc_usage(dlm, res);
 
         wake_up(&res->wq);
         return status;