On Mon, Jul 31, 2023 at 10:02:39PM +0800, Chengming Zhou wrote: > The commit 84fca1b0c461 ("block: pass failfast and driver-specific flags to > flush requests") says: > If flush requests are being sent to the device we need to inherit the > failfast and driver-specific flags, too, otherwise I/O will fail. > > 1) REQ_FAILFAST_MASK: agree, shouldn't set to the flush_rq I think? > 2) REQ_DRV: I don't get why this flag not set would cause I/O fail? I don't think it would fail I/O by it's own, but it will cause the nvme driver to not do the correct handling of an error when a flush is set to multipath setups.