disable directio for unaligned reads in Linux
diff --git a/auto/os/features b/auto/os/features
index 8efed75..5fcbf7f 100644
--- a/auto/os/features
+++ b/auto/os/features
@@ -182,6 +182,10 @@
 . auto/feature
 
 
+if [ $ngx_found = yes -a "$NGX_SYSTEM" = "Linux" ]; then
+    have=NGX_HAVE_ALIGNED_DIRECTIO . auto/have
+fi
+
 ngx_feature="F_NOCACHE"
 ngx_feature_name="NGX_HAVE_F_NOCACHE"
 ngx_feature_run=no