Merge remote-tracking branch 'lsk/v3.10/topic/of' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / drivers / xen / grant-table.c

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 04c1b2d9b77514ca89ef1cf74d6263f5ebb93a29..840604ed0235b55ec33dc50fea065d20834d8c32 100644 (file)
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -729,9 +729,18 @@ void gnttab_request_free_callback(struct gnttab_free_callback *callback,
                                  void (*fn)(void *), void *arg, u16 count)
 {
        unsigned long flags;
+       struct gnttab_free_callback *cb;
+
        spin_lock_irqsave(&gnttab_list_lock, flags);
-       if (callback->next)
-               goto out;
+
+       /* Check if the callback is already on the list */
+       cb = gnttab_free_callback_list;
+       while (cb) {
+               if (cb == callback)
+                       goto out;
+               cb = cb->next;
+       }
+
        callback->fn = fn;
        callback->arg = arg;
        callback->count = count;
@@ -911,9 +920,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                ret = m2p_add_override(mfn, pages[i], kmap_ops ?
                                       &kmap_ops[i] : NULL);
                if (ret)
-                       return ret;
+                       goto out;
        }
 
+ out:
        if (lazy)
                arch_leave_lazy_mmu_mode();
 
@@ -944,9 +954,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
                ret = m2p_remove_override(pages[i], kmap_ops ?
                                       &kmap_ops[i] : NULL);
                if (ret)
-                       return ret;
+                       goto out;
        }
 
+ out:
        if (lazy)
                arch_leave_lazy_mmu_mode();