From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rutger ter Borg Subject: Rados and user-provided buffers Date: Wed, 18 Sep 2013 21:57:55 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from plane.gmane.org ([80.91.229.3]:43430 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753430Ab3IRT6G (ORCPT ); Wed, 18 Sep 2013 15:58:06 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1VMNsz-0006p8-OA for ceph-devel@vger.kernel.org; Wed, 18 Sep 2013 21:58:05 +0200 Received: from 77-173-143-102.ip.telfort.nl ([77.173.143.102]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 18 Sep 2013 21:58:05 +0200 Received: from rutger by 77-173-143-102.ip.telfort.nl with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 18 Sep 2013 21:58:05 +0200 Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Dear all, I've a question regarding buffers in rados (using the C++ API). I'm allocating and using my own buffers, and would like to read and write directly into and from them. I'm using a bufferlist consisting of static_buffers, which are passed to Rados' aio_read and aio_write. For aio_write, rados works as expected, i.e., the bufferlist is returned as it was before the call. However, when doing aio_read, it seems that the bufferlist is destroyed (not used) in the call, despite all the buffers being static. Is this expected behaviour? I read a thread "read/write on RADOS using external buffer" from this mailing list from 2010, but wasn't able to figure out whether rados does or doesn't support reading into user-provided static_buffers. Thanks in advance, Cheers, Rutger