From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changli Gao Subject: Re: [PATCH 2/3] splice: allow non-block splice only when in file is seekable Date: Wed, 26 May 2010 19:53:53 +0800 Message-ID: References: <1274867768-3011-1-git-send-email-xiaosuo@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Miklos Szeredi Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, May 26, 2010 at 6:29 PM, Miklos Szeredi wro= te: > On Wed, 26 May 2010, Changli Gao wrote: >> allow non-block splice only when in file is seekable. >> >> do_splice_to() is split to two parts: read data from in file to spd,= and move >> data from spd to pipe. If there isn't much space in pipe for the dat= a in spd, >> and the splice is called with non-block flag, the data dropped due t= o non >> enough space in pipe will be lost forever when in file isn't seekabl= e. > > This is a gratuitous ABI change. =C2=A0I don't think we should hold t= he > hand of application writers, Yea, it is an ABI change. But without that, we'll fail user silently currently. Some fundamental change is needed to fix this issue fully, if you think it is a bug. > maybe they _know_ the splice will not > block. > If they know the splice won't block, why he specifies a non-block flag? --=20 Regards=EF=BC=8C Changli Gao(xiaosuo@gmail.com)