From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:36196 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932123AbbIXSKJ (ORCPT ); Thu, 24 Sep 2015 14:10:09 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZfAy5-0004Xz-56 for linux-btrfs@vger.kernel.org; Thu, 24 Sep 2015 20:10:05 +0200 Received: from 92.243.181.209 ([92.243.181.209]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 24 Sep 2015 20:10:05 +0200 Received: from matwey.kornilov by 92.243.181.209 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 24 Sep 2015 20:10:05 +0200 To: linux-btrfs@vger.kernel.org From: "Matwey V. Kornilov" Subject: btrfs: obtain block checksums from user space Date: Thu, 24 Sep 2015 21:06:32 +0300 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hello, I would like to read the list of the checksums for the specific file stored onto btrfs filesystem. I think I could use the checksums in the manner like rsync does, but safe both CPU (because csums are already calculated for the file) and I/O (because I don't need to reread all the file from the hard drive). I've looked through linux kernel sources and not found appropriate ioctl to do this. Frankly speaking, I've not found good documentations for all available btrfs ioctls.