Merge branch 'xen/xenbus' into upstream/xen

* xen/xenbus:
  implement O_NONBLOCK for /proc/xen/xenbus
  xenbus: do not hold transaction_mutex when returning to userspace

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/xen/xenfs/xenbus.c b/drivers/xen/xenfs/xenbus.c
index f28ece397361..3b39c3752e21 100644
--- a/drivers/xen/xenfs/xenbus.c
+++ b/drivers/xen/xenfs/xenbus.c
@@ -124,6 +124,9 @@ static ssize_t xenbus_file_read(struct file *filp,
         mutex_lock(&u->reply_mutex);
         while (list_empty(&u->read_buffers)) {
                 mutex_unlock(&u->reply_mutex);
+                if (filp->f_flags & O_NONBLOCK)
+                        return -EAGAIN;
+
                 ret = wait_event_interruptible(u->read_waitq,
                                                !list_empty(&u->read_buffers));
                 if (ret)