xen: avoid allocation causing potential swap activity on the resume path

Since the device we are resuming could be the device containing the
swap device we should ensure that the allocation cannot cause
IO.

On resume, this path is triggered when the running system tries to
continue using its devices.  If it cannot then the resume will fail;
to try to avoid this we let it dip into the emergency pools.

The majority of these changes were made when linux-2.6.18-xen.hg
changeset e8b49cfbdac0 was ported upstream in
a144ff09bc52ef3f3684ed23eadc9c7c0e57b3aa but somehow this hunk was
dropped.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Stable Kernel <stable@kernel.org> # .32.x

diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index eab33f1dbdf7013f451af491b882973ea017f718..7b547f53f65ee9267f19dd493a6ab7321310ed4c 100644 (file)
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -499,7 +499,7 @@ int xenbus_printf(struct xenbus_transaction t,
 #define PRINTF_BUFFER_SIZE 4096
        char *printf_buffer;
 
-       printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL);
+       printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_NOIO | __GFP_HIGH);
        if (printf_buffer == NULL)
                return -ENOMEM;