From dcb8baeceaa1c629bbd06f472cea023ad08a0c33 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 2 Nov 2010 11:55:58 -0400 Subject: [PATCH] xen/blkfront: cope with backend that fail empty BLKIF_OP_WRITE_BARRIER requests Some(?) Xen block backends fail BLKIF_OP_WRITE_BARRIER requests, which Linux uses as a cache flush operation. In that case, disable use of FLUSH. Signed-off-by: Jeremy Fitzhardinge Cc: Daniel Stodden --- drivers/block/xen-blkfront.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 76b874a79175..4f9e22f29138 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -656,6 +656,16 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) printk(KERN_WARNING "blkfront: %s: write barrier op failed\n", info->gd->disk_name); error = -EOPNOTSUPP; + } + if (unlikely(bret->status == BLKIF_RSP_ERROR && + info->shadow[id].req.nr_segments == 0)) { + printk(KERN_WARNING "blkfront: %s: empty write barrier op failed\n", + info->gd->disk_name); + error = -EOPNOTSUPP; + } + if (unlikely(error)) { + if (error == -EOPNOTSUPP) + error = 0; info->feature_flush = 0; xlvbd_flush(info); } -- 2.39.2