epoll: don't use current in irq context

[safe/jmp/linux-2.6] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 205a1e1..db4365f 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -97,8 +97,8 @@ struct epoll_filefd {
  */
 struct nested_call_node {
        struct list_head llink;
-       struct task_struct *task;
        void *cookie;
+       int cpu;
 };
 
 /*
@@ -327,7 +327,7 @@ static int ep_call_nested(struct nested_calls *ncalls, int max_nests,
 {
        int error, call_nests = 0;
        unsigned long flags;
-       struct task_struct *this_task = current;
+       int this_cpu = get_cpu();
        struct list_head *lsthead = &ncalls->tasks_call_list;
        struct nested_call_node *tncur;
        struct nested_call_node tnode;
@@ -340,20 +340,19 @@ static int ep_call_nested(struct nested_calls *ncalls, int max_nests,
         * very much limited.
         */
        list_for_each_entry(tncur, lsthead, llink) {
-               if (tncur->task == this_task &&
+               if (tncur->cpu == this_cpu &&
                    (tncur->cookie == cookie || ++call_nests > max_nests)) {
                        /*
                         * Ops ... loop detected or maximum nest level reached.
                         * We abort this wake by breaking the cycle itself.
                         */
-                       spin_unlock_irqrestore(&ncalls->lock, flags);
-
-                       return -1;
+                       error = -1;
+                       goto out_unlock;
                }
        }
 
        /* Add the current task and cookie to the list */
-       tnode.task = this_task;
+       tnode.cpu = this_cpu;
        tnode.cookie = cookie;
        list_add(&tnode.llink, lsthead);
 
@@ -365,8 +364,10 @@ static int ep_call_nested(struct nested_calls *ncalls, int max_nests,
        /* Remove the current task from the list */
        spin_lock_irqsave(&ncalls->lock, flags);
        list_del(&tnode.llink);
+ out_unlock:
        spin_unlock_irqrestore(&ncalls->lock, flags);
 
+       put_cpu();
        return error;
 }