On 04/15/2016 05:50 AM, Juergen Gross wrote:

On 15/04/16 12:40, mchristi@redhat.com wrote:

quoted

From: Mike Christie <redacted>

The last patch added a REQ_OP_FLUSH for request_fn drivers
and the next patch renames REQ_FLUSH to REQ_PREFLUSH which
will be used by file systems and make_request_fn drivers so
they can send a write/flush combo.

This patch drops xen's use of REQ_FLUSH to track if it supports
REQ_OP_FLUSH requests, so REQ_FLUSH can be deleted.

v6:
- Dropped parts of patch handled by Jens's QUEUE_FLAG_WC/FUA
patches and modified patch to check feature_flush/fua bits.

Signed-off-by: Mike Christie <redacted>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 drivers/block/xen-blkfront.c | 47 ++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 23 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f01691a..d6429e7 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c

...

quoted

@@ -985,24 +981,22 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
 	return 0;
 }
 
-static const char *flush_info(unsigned int feature_flush)
+static const char *flush_info(struct blkfront_info *info)
 {
-	switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) {
-	case REQ_FLUSH|REQ_FUA:
+	if (info->feature_flush && info->feature_fua)
 		return "barrier: enabled;";
-	case REQ_FLUSH:
+	else if (info->feature_fua)

Shouldn't this test feature_flush?

quoted

 		return "flush diskcache: enabled;";
-	default:
+	else
 		return "barrier or flush: disabled;";
-	}
 }
 
 static void xlvbd_flush(struct blkfront_info *info)
 {
-	blk_queue_write_cache(info->rq, info->feature_flush & REQ_FLUSH,
-				info->feature_flush & REQ_FUA);
+	blk_queue_write_cache(info->rq, info->feature_flush ? true : false,
+			      info->feature_flush ? true : false);

And here the second test should be feature_fua?

You are right. Will fix up and resend.