From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.9]:35462 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752099AbbJPMZq (ORCPT ); Fri, 16 Oct 2015 08:25:46 -0400 Date: Fri, 16 Oct 2015 05:25:44 -0700 From: Christoph Hellwig To: Chris Mason , Christoph Hellwig , "Darrick J. Wong" , P??draig Brady , Anna Schumaker , linux-nfs@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, zab@zabbo.net, viro@zeniv.linux.org.uk, mtk.manpages@gmail.com, andros@netapp.com Subject: Re: [PATCH v5 9/9] btrfs: btrfs_copy_file_range() only supports reflinks Message-ID: <20151016122544.GC5889@infradead.org> References: <1443634014-3026-1-git-send-email-Anna.Schumaker@Netapp.com> <1443634014-3026-10-git-send-email-Anna.Schumaker@Netapp.com> <20151011142939.GA30905@infradead.org> <561B8A09.5070507@draigBrady.com> <20151012143444.GA10156@infradead.org> <20151012234106.GD11398@birch.djwong.org> <20151013072959.GB10794@infradead.org> <20151014184608.GK850@birch.djwong.org> <20151015060045.GA23996@infradead.org> <20151016114919.GB6874@ret.masoncoding.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20151016114919.GB6874@ret.masoncoding.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Oct 16, 2015 at 07:49:19AM -0400, Chris Mason wrote: > > Yes, that would be my preference. I'd also like to understand what > > exactly btrfs does in fallocate. > > For which part? The answer changes based on how many references there > are to a given fallocated region. Both cases. With btrfs allocating new block on every write how do you avoid that ENOSPC? Is there a unassigned block preallocation that's made persistent in some way? From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH v5 9/9] btrfs: btrfs_copy_file_range() only supports reflinks Date: Fri, 16 Oct 2015 05:25:44 -0700 Message-ID: <20151016122544.GC5889@infradead.org> References: <1443634014-3026-1-git-send-email-Anna.Schumaker@Netapp.com> <1443634014-3026-10-git-send-email-Anna.Schumaker@Netapp.com> <20151011142939.GA30905@infradead.org> <561B8A09.5070507@draigBrady.com> <20151012143444.GA10156@infradead.org> <20151012234106.GD11398@birch.djwong.org> <20151013072959.GB10794@infradead.org> <20151014184608.GK850@birch.djwong.org> <20151015060045.GA23996@infradead.org> <20151016114919.GB6874@ret.masoncoding.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Chris Mason , Christoph Hellwig , "Darrick J. Wong" , P??draig Brady , Anna Schumaker , linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, zab-ugsP4Wv/S6ZeoWH0uzbU5w@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, andros-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org Return-path: Content-Disposition: inline In-Reply-To: <20151016114919.GB6874-DzB2rL6jT1BHfPKRx072akEOCMrvLtNR@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Fri, Oct 16, 2015 at 07:49:19AM -0400, Chris Mason wrote: > > Yes, that would be my preference. I'd also like to understand what > > exactly btrfs does in fallocate. > > For which part? The answer changes based on how many references there > are to a given fallocated region. Both cases. With btrfs allocating new block on every write how do you avoid that ENOSPC? Is there a unassigned block preallocation that's made persistent in some way?