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

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

diff --git a/fs/ocfs2/dlm/userdlm.c b/fs/ocfs2/dlm/userdlm.c
index 808ec0527c75348b42c000f0a2545462cf243b54..74ca4e5f9765aba66cc342af3876731aba199428 100644 (file)
--- 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);