ocfs2: Handle the DLM_CANCELGRANT case in user_unlock_ast()

Remove the code which attempted to catch it via dlmunlock() return status -
this never happens there.

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

1 files changed, 22 insertions, 12 deletions

diff --git a/fs/ocfs2/dlm/userdlm.c b/fs/ocfs2/dlm/userdlm.c
index d0f1027a3853..808ec0527c75 100644
--- a/fs/ocfs2/dlm/userdlm.c
+++ b/fs/ocfs2/dlm/userdlm.c
@@ -233,23 +233,38 @@ static void user_unlock_ast(void *opaque, enum dlm_status status)
 
         mlog(0, "UNLOCK AST called on lock %s\n", lockres->l_name);
 
-        if (status != DLM_NORMAL)
+        if (status != DLM_NORMAL && status != DLM_CANCELGRANT)
                 mlog(ML_ERROR, "Dlm returns status %d\n", status);
 
         spin_lock(&lockres->l_lock);
         if (lockres->l_flags & USER_LOCK_IN_TEARDOWN)
                 lockres->l_level = LKM_IVMODE;
-        else {
+        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
+                 * already granted. Don't clear the busy flag - the
+                 * ast should've done this already. */
+                BUG_ON(!(lockres->l_flags & USER_LOCK_IN_CANCEL));
+                lockres->l_flags &= ~USER_LOCK_IN_CANCEL;
+                goto out_noclear;
+        } else {
+                BUG_ON(!(lockres->l_flags & USER_LOCK_IN_CANCEL));
+                /* Cancel succeeded, we want to re-queue */
+                mlog(0, "Lock %s, cancel succeeds, flags 0x%x\n",
+                     lockres->l_name, lockres->l_flags);
                 lockres->l_requested = LKM_IVMODE; /* cancel an
                                                     * upconvert
                                                     * request. */
                 lockres->l_flags &= ~USER_LOCK_IN_CANCEL;
                 /* we want the unblock thread to look at it again
                  * now. */
-                __user_dlm_queue_lockres(lockres);
+                if (lockres->l_flags & USER_LOCK_BLOCKED)
+                        __user_dlm_queue_lockres(lockres);
         }
 
         lockres->l_flags &= ~USER_LOCK_BUSY;
+out_noclear:
         spin_unlock(&lockres->l_lock);
 
         wake_up(&lockres->l_event);
@@ -299,7 +314,9 @@ static void user_dlm_unblock_lock(void *opaque)
         }
 
         if (lockres->l_flags & USER_LOCK_BUSY) {
-                mlog(0, "BUSY flag detected...\n");
+                mlog(0, "Cancel lock %s, flags 0x%x\n",
+                     lockres->l_name, lockres->l_flags);
+
                 if (lockres->l_flags & USER_LOCK_IN_CANCEL) {
                         spin_unlock(&lockres->l_lock);
                         goto drop_ref;
@@ -313,14 +330,7 @@ static void user_dlm_unblock_lock(void *opaque)
                                    LKM_CANCEL,
                                    user_unlock_ast,
                                    lockres);
-                if (status == DLM_CANCELGRANT) {
-                        /* If we got this, then the ast was fired
-                         * before we could cancel. We cleanup our
-                         * state, and restart the function. */
-                        spin_lock(&lockres->l_lock);
-                        lockres->l_flags &= ~USER_LOCK_IN_CANCEL;
-                        spin_unlock(&lockres->l_lock);
-                } else if (status != DLM_NORMAL)
+                if (status != DLM_NORMAL)
                         user_log_dlm_error("dlmunlock", status, lockres);
                 goto drop_ref;
         }