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authorJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2010-11-02 11:55:58 -0400
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2010-11-02 13:46:46 -0400
commitdcb8baeceaa1c629bbd06f472cea023ad08a0c33 (patch)
tree72145e182cac0705e80553565356db24a41387e6 /drivers/block/xen-blkfront.c
parentbe2f8373c188ed1f5d36003c9928e4d695213080 (diff)
downloadlinux-dcb8baeceaa1c629bbd06f472cea023ad08a0c33.tar.gz
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 <jeremy.fitzhardinge@citrix.com> Cc: Daniel Stodden <daniel.stodden@citrix.com>
Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 76b874a7917..4f9e22f2913 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);
}