diff options
Diffstat (limited to 'drivers/xen/grant-table.c')
| -rw-r--r-- | drivers/xen/grant-table.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index fd725cd..949af52 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -355,9 +355,18 @@ 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; |