From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: Proposal to improve filesystem/block snapshot interaction Date: Tue, 30 Oct 2007 11:15:29 +0100 Message-ID: <200710301115.30376.arnd@arndb.de> References: <20070927063113.GD2989@sgi.com> <20071030010453.GF27385@sgi.com> <7fe698080710300235v3ce49613nfe3c5e733f1b6f5b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: "Greg Banks" , "Linux Filesystem Mailing List" , "David Chinner" , "Donald Douwsma" , "Christoph Hellwig" , "Roger Strassburg" , "Mark Goodwin" , "Brett Jon Grandbois" To: "Dongjun Shin" Return-path: Received: from moutng.kundenserver.de ([212.227.126.188]:55143 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751351AbXJ3KPx (ORCPT ); Tue, 30 Oct 2007 06:15:53 -0400 In-Reply-To: <7fe698080710300235v3ce49613nfe3c5e733f1b6f5b@mail.gmail.com> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tuesday 30 October 2007, Dongjun Shin wrote: > There is an ongoing discussion about adding 'Trim' ATA command for notifying > the drive about the deleted blocks. > > http://www.t13.org/Documents/UploadedDocuments/docs2007/e07154r3-Data_Set_Management_Proposal_for_ATA-ACS2.pdf > > This is especially useful for the storage device like Solid State Drive (SSD). > This make me curious, why would t13 want to invent a new command when there is already the erase command from CFA? It's not exactly the same, but close enough that the proposed BIO_HINT_RELEASE should probably be mapped to CFA_ERASE (0xc0) on drives that support it: http://t13.org/Documents/UploadedDocuments/technical/d97116r1.pdf Arnd <><