Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267396AbUIFHGg (ORCPT ); Mon, 6 Sep 2004 03:06:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267491AbUIFHGg (ORCPT ); Mon, 6 Sep 2004 03:06:36 -0400 Received: from castle.nmd.msu.ru ([193.232.112.53]:12048 "HELO castle.nmd.msu.ru") by vger.kernel.org with SMTP id S267396AbUIFHGb (ORCPT ); Mon, 6 Sep 2004 03:06:31 -0400 Message-ID: <20040906110628.A31962@castle.nmd.msu.ru> Date: Mon, 6 Sep 2004 11:06:28 +0400 From: Andrey Savochkin To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: Re: Q about pagecache data never written to disk References: <20040905120147.A9202@castle.nmd.msu.ru> <20040905035233.6a6b5823.akpm@osdl.org> <20040905154336.B9202@castle.nmd.msu.ru> <20040905140040.58a5fcdc.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.93.2i In-Reply-To: <20040905140040.58a5fcdc.akpm@osdl.org>; from "Andrew Morton" on Sun, Sep 05, 2004 at 02:00:40PM Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1448 Lines: 34 On Sun, Sep 05, 2004 at 02:00:40PM -0700, Andrew Morton wrote: > Andrey Savochkin wrote: > > On Sun, Sep 05, 2004 at 03:52:33AM -0700, Andrew Morton wrote: > > > That would be a retrograde step - it would be nice to move in the other > > > direction: perform disk allocation at writeback time rather than at write() > > > time, even for regular write() data. To do that we (probably) need space > > > reservation APIs. And yes, we perhaps could reserve space in the > > > filesystem when that page is first written to. > > > > > > But then what would we do if there's no space? SIGBUS? SIGSEGV? > > > Inappropriate. SIGENOSPC? > > > > Should the space be allocated on close()? > > What effect are you trying to achieve? Sending a signal while there is still a process... > > Who will get the signal if nobody accesses the file anymore? > > Nobody. That's the point. Plus there _is_ no signal defined for this. > Neither in Linux nor in POSIX. > > > I'm also thinking about various shell scripts with redirects to files... > > ? I doubt that they're writing files via MAP_SHARED. I was deliberating on your idea about delayed allocation for regular write()s also... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/