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>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f2ffc46644df..739b4c1416ea 100644
--- 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) {