+ write_unlock_irq(&fasync_lock);
+ spin_unlock(&filp->f_lock);
+ return result;
+}
+
+/*
+ * Add a fasync entry. Return negative on error, positive if
+ * added, and zero if did nothing but change an existing one.
+ *
+ * NOTE! It is very important that the FASYNC flag always
+ * match the state "is the filp on a fasync list".
+ */
+static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
+{
+ struct fasync_struct *new, *fa, **fp;
+ int result = 0;
+
+ new = kmem_cache_alloc(fasync_cache, GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;