1 files changed, 13 insertions, 0 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 8d9298c99763..d5b2d2bbf5ff 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -187,6 +187,19 @@ free_address(
 {
         a_list_t        *aentry;
 
+#ifdef CONFIG_XEN
+        /*
+         * Xen needs to be able to make sure it can get an exclusive
+         * RO mapping of pages it wants to turn into a pagetable.  If
+         * a newly allocated page is also still being vmap()ed by xfs,
+         * it will cause pagetable construction to fail.  This is a
+         * quick workaround to always eagerly unmap pages so that Xen
+         * is happy.
+         */
+        vunmap(addr);
+        return;
+#endif
+
         aentry = kmalloc(sizeof(a_list_t), GFP_NOWAIT);
         if (likely(aentry)) {
                 spin_lock(&as_lock);