xen-blkfront: disable barrier/flush write support

The driver doesn't handle empty flushes. Disable barrier/flush
write support until this is fixed up.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f2ffc46644df11fdcd02b4b9ca3749105a07d5b1..739b4c1416eab3b4aac7cc2389bec131b4a09752 100644 (file)
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1067,8 +1067,15 @@ static void blkfront_connect(struct blkfront_info *info)
         * If there are barriers, then we use flush.
         */
        info->feature_flush = 0;
+
+       /*
+        * The driver doesn't properly handled empty flushes, so
+        * lets disable barrier support for now.
+        */
+#if 0
        if (!err && barrier)
                info->feature_flush = REQ_FLUSH;
+#endif
 
        err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
        if (err) {