Forgot to add net/ipv4/tcp_zero_copy.c from put_page_callback patch

diff --git a/net/ipv4/tcp_zero_copy.c b/net/ipv4/tcp_zero_copy.c
new file mode 100644 (file)
index 0000000..9cd990c
--- /dev/null
+++ b/net/ipv4/tcp_zero_copy.c
@@ -0,0 +1,49 @@
+/*
+ *     Support routines for TCP zero copy transmit
+ *
+ *     Created by Vladislav Bolkhovitin
+ *
+ *     This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/skbuff.h>
+
+net_get_page_callback_t net_get_page_callback __read_mostly;
+EXPORT_SYMBOL(net_get_page_callback);
+
+net_put_page_callback_t net_put_page_callback __read_mostly;
+EXPORT_SYMBOL(net_put_page_callback);
+
+/*
+ * Caller of this function must ensure that at the moment when it's called
+ * there are no pages in the system with net_priv field set to non-zero
+ * value. Hence, this function, as well as net_get_page() and net_put_page(),
+ * don't need any protection.
+ */
+int net_set_get_put_page_callbacks(
+       net_get_page_callback_t get_callback,
+       net_put_page_callback_t put_callback)
+{
+       int res = 0;
+
+       if ((net_get_page_callback != NULL) && (get_callback != NULL) &&
+           (net_get_page_callback != get_callback)) {
+               res = -EBUSY;
+               goto out;
+       }
+
+       if ((net_put_page_callback != NULL) && (put_callback != NULL) &&
+           (net_put_page_callback != put_callback)) {
+               res = -EBUSY;
+               goto out;
+       }
+
+       net_get_page_callback = get_callback;
+       net_put_page_callback = put_callback;
+
+out:
+       return res;
+}
+EXPORT_SYMBOL(net_set_get_put_page_callbacks);