From: Andreas Dilger Subject: Re: [PATCH 1/3] Implement generic freeze feature Date: Fri, 22 Aug 2008 01:09:58 -0600 Message-ID: <20080822070958.GU3392@webber.adilger.int> References: <20080818212819t-sato@mail.jp.nec.com> <20080821125841.a04a706f.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Cc: Takashi Sato , linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, viro@ZenIV.linux.org.uk, linux-ext4@vger.kernel.org, xfs@oss.sgi.com, hch@infradead.org, axboe@kernel.dk, mtk.manpages@googlemail.com, linux-kernel@vger.kernel.org To: Andrew Morton Return-path: Received: from sca-es-mail-1.Sun.COM ([192.18.43.132]:61796 "EHLO sca-es-mail-1.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753644AbYHVHKL (ORCPT ); Fri, 22 Aug 2008 03:10:11 -0400 In-reply-to: <20080821125841.a04a706f.akpm@linux-foundation.org> Content-disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: On Aug 21, 2008 12:58 -0700, Andrew Morton wrote: > > #define FIGETBSZ _IO(0x00,2) /* get the block size used for bmap */ > > +#define FIFREEZE _IOWR('X', 119, int) /* Freeze */ > > +#define FITHAW _IOWR('X', 120, int) /* Thaw */ > > FIFREEZE is 119, but a few lines above we have > > #define BLKDISCARD _IO(0x12,119) > > Should we be using 120 and 121 here? No, because 'X' != 0x12... The 'X' is used because this ioctl is compatible with the XFS implementation of this feature. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.