From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Mon, 23 Jun 2008 23:58:51 -0700 (PDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m5O6wira019551 for ; Mon, 23 Jun 2008 23:58:44 -0700 Received: from tyo201.gate.nec.co.jp (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 76BAED2ED37 for ; Mon, 23 Jun 2008 23:59:43 -0700 (PDT) Received: from tyo201.gate.nec.co.jp (TYO201.gate.nec.co.jp [202.32.8.193]) by cuda.sgi.com with ESMTP id EXAZFe5RhgXPBijG for ; Mon, 23 Jun 2008 23:59:43 -0700 (PDT) Subject: [PATCH 0/3] freeze feature ver 1.6 Message-Id: <20080624155919t-sato@mail.jp.nec.com> Mime-Version: 1.0 From: Takashi Sato Date: Tue, 24 Jun 2008 15:59:19 +0900 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: akpm@linux-foundation.org, viro@ZenIV.linux.org.uk Cc: "linux-ext4@vger.kernel.org" , "xfs@oss.sgi.com" , "dm-devel@redhat.com" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , axboe@kernel.dk, mtk.manpages@googlemail.com Hi Andrew and Alexander, I have implemented the ioctls for the filesystem freeze feature and discussed its implementation on the ML (linux-ext4, xfs, linux-fsdevel, linux-kernel) for five months. All of the comments are addressed in my patch-set. Could you consider merging it into Linux? The filesystem freeze feature can suspend accesses to the filesystem keeping the filesystem's consistency. We can take the consistent backup with it cooperating with the backup software. The patches are re-based from linux-2.6.26-rc3 to linux-2.6.26-rc7 There is no functional change from the previous version. The patch-set consists of the following three patches. [PATCH 1/3] Implement generic freeze feature I have modified to set the suitable error number (EOPNOTSUPP) in case the filesystem doesn't support the freeze feature. The ioctls for the generic freeze feature are below. o Freeze the filesystem int ioctl(int fd, int FIFREEZE, arg) fd: The file descriptor of the mountpoint FIFREEZE: request code for the freeze arg: Ignored Return value: 0 if the operation succeeds. Otherwise, -1 o Unfreeze the filesystem int ioctl(int fd, int FITHAW, arg) fd: The file descriptor of the mountpoint FITHAW: request code for unfreeze arg: Ignored Return value: 0 if the operation succeeds. Otherwise, -1 [PATCH 2/3] Remove XFS specific ioctl interfaces for freeze feature It removes XFS specific ioctl interfaces and request codes for freeze feature. This patch has been supplied by David Chinner. [PATCH 3/3] Add timeout feature The timeout feature is added to freeze ioctl. And new ioctl to reset the timeout period is added. o Freeze the filesystem int ioctl(int fd, int FIFREEZE, long *timeval) fd: The file descriptor of the mountpoint FIFREEZE: request code for the freeze timeval: the timeout period in seconds If it's 0 or 1, the timeout isn't set. This special case of "1" is implemented to keep the compatibility with XFS applications. Return value: 0 if the operation succeeds. Otherwise, -1 o Reset the timeout period This is useful for the application to set the timeval more accurately. For example, the freezer resets the timeval to 10 seconds every 5 seconds. In this approach, even if the freezer causes a deadlock by accessing the frozen filesystem, it will be solved by the timeout in 10 seconds and the freezer can recognize that at the next reset of timeval. int ioctl(int fd, int FIFREEZE_RESET_TIMEOUT, long *timeval) fd:file descriptor of mountpoint FIFREEZE_RESET_TIMEOUT: request code for reset of timeout period timeval: new timeout period in seconds Return value: 0 if the operation succeeds. Otherwise, -1 Error number: If the filesystem has already been unfrozen, errno is set to EINVAL. Any comments are very welcome. Cheers, Takashi