On Fri, 15 May 2015, Alan Stern wrote: > On Fri, 15 May 2015, NeilBrown wrote: > > > Some storage devices don't handle suspend as well as they should and lose > > requests resulting in corruption. They should obviously be fixed, but it is > > you who gets the problem reports and you are not in a position to fix them. > > So you want a general solution that hides those problems. > > sys_sync at suspend time is a sort-of solution because it flushes and waits > > so there is less in-flight IO immediately after a sys_sync and so less > > opportunity for a bad device to stuff up. > > But you seem to suggest that sys_sync isn't a complete solution and it > > doesn't guarantee that xfs is not doing some background metadata IO. > > > > Maybe a sensible thing to do would be to hook the "disk" devices into > > suspend > > and have them flush their queue and possibly send a CACHE_FLUSH command. > > That would provide more of a guarantee for you, and less of a cost for Len, > > would it not? > > The sd driver already does this.
Sorry -- I meant that it does send a SYNCHRONIZE CACHE command. It doesn't flush the I/O queue. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
