path: root/drivers/block/xen-blkfront.c
diff options
authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-09-16 15:15:14 -0400
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-10-13 09:48:35 -0400
commitd11e6158307bed3f178399a4e6216eec67d16200 (patch)
treec5fa6989bcba7d39b3924628c60e386e3f24edcc /drivers/block/xen-blkfront.c
parent8e6dc6fe51957116d363204a725c1262b4b78e19 (diff)
xen-blkfront: If no barrier or flush is supported, use invalid operation.
Guard against issuing BLKIF_OP_WRITE_BARRIER or BLKIF_OP_FLUSH_CACHE by checking whether we successfully negotiated with the backend. The negotiation with the backend also sets the q->flush_flags which fortunately for us is also used when submitting an bio to us. If we don't support barriers or flushes it would be set to zero so we should never end up having to deal with REQ_FLUSH | REQ_FUA. However, other third party implementations of __make_request that might be stacked on top of us might not be so smart, so lets fix this up. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkfront.c')
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 7d148776028..8bf0cb7b256 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -380,7 +380,9 @@ static void do_blkif_request(struct request_queue *rq)
- if (req->cmd_type != REQ_TYPE_FS) {
+ if ((req->cmd_type != REQ_TYPE_FS) ||
+ ((req->cmd_flags & (REQ_FLUSH | REQ_FUA)) &&
+ !info->flush_op)) {
__blk_end_request_all(req, -EIO);