ocfs2: test and set teardown flag early in user_dlm_destroy_lock()

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 14 insertions, 3 deletions

diff --git a/fs/ocfs2/dlm/userdlm.c b/fs/ocfs2/dlm/userdlm.c
index 808ec0527c75..74ca4e5f9765 100644
--- a/fs/ocfs2/dlm/userdlm.c
+++ b/fs/ocfs2/dlm/userdlm.c
@@ -237,9 +237,13 @@ static void user_unlock_ast(void *opaque, enum dlm_status status)
                 mlog(ML_ERROR, "Dlm returns status %d\n", status);
 
         spin_lock(&lockres->l_lock);
-        if (lockres->l_flags & USER_LOCK_IN_TEARDOWN)
+        /* The teardown flag gets set early during the unlock process,
+         * so test the cancel flag to make sure that this ast isn't
+         * for a concurrent cancel. */
+        if (lockres->l_flags & USER_LOCK_IN_TEARDOWN
+            && !(lockres->l_flags & USER_LOCK_IN_CANCEL)) {
                 lockres->l_level = LKM_IVMODE;
-        else if (status == DLM_CANCELGRANT) {
+        } else if (status == DLM_CANCELGRANT) {
                 mlog(0, "Lock %s, cancel fails, flags 0x%x\n",
                      lockres->l_name, lockres->l_flags);
                 /* We tried to cancel a convert request, but it was
@@ -608,6 +612,14 @@ int user_dlm_destroy_lock(struct user_lock_res *lockres)
         mlog(0, "asked to destroy %s\n", lockres->l_name);
 
         spin_lock(&lockres->l_lock);
+        if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) {
+                mlog(0, "Lock is already torn down\n");
+                spin_unlock(&lockres->l_lock);
+                return 0;
+        }
+
+        lockres->l_flags |= USER_LOCK_IN_TEARDOWN;
+
         while (lockres->l_flags & USER_LOCK_BUSY) {
                 spin_unlock(&lockres->l_lock);
 
@@ -633,7 +645,6 @@ int user_dlm_destroy_lock(struct user_lock_res *lockres)
 
         lockres->l_flags &= ~USER_LOCK_ATTACHED;
         lockres->l_flags |= USER_LOCK_BUSY;
-        lockres->l_flags |= USER_LOCK_IN_TEARDOWN;
         spin_unlock(&lockres->l_lock);
 
         mlog(0, "unlocking lockres %s\n", lockres->l_name);