On Thu, Aug 30, 2012 at 6:03 PM, Andrew Morton <a...@linux-foundation.org> wrote: > On Wed, 29 Aug 2012 08:41:02 -0400 > paul.cleme...@steeleye.com wrote: > >> Description: This patch adds discard support to nbd. When the nbd client >> system receives a discard request, this will be passed along to the nbd >> server system, where the nbd-server will respond by performing: >> fallocate(.. FALLOC_FL_PUNCH_HOLE ..) >> >> To punch a hole in the backend storage, which is no longer needed. >> > > What happens if the user is running an older server?
In that case, the older server will not have set NBD_SEND_FLAG_TRIM, so QUEUE_FLAG_DISCARD doesn't get set, so no discards will be sent to the device. > I is it possible that because the old server didn't set > NBD_FLAG_SEND_TRIM, the user's screen gets filled with WARN_ONs? No. > Anyway, please make sure this combination was tested! It was. Thanks for the feedback. I will resend v2 of the patches shortly. -- Paul -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
