From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o3KGxERd051550 for ; Tue, 20 Apr 2010 11:59:15 -0500 Received: from mx1.redhat.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id A56711DD832F for ; Tue, 20 Apr 2010 10:01:14 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id 9QiRNaGDhNAn7LMo for ; Tue, 20 Apr 2010 10:01:14 -0700 (PDT) Message-ID: <4BCDDDD0.9000808@sandeen.net> Date: Tue, 20 Apr 2010 12:01:04 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: do we support using a file as logdev? References: <20100420143656.GA3634@laptop.oracle.com> In-Reply-To: <20100420143656.GA3634@laptop.oracle.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Wengang Wang Cc: greg.marsden@oracle.com, joe.jin@oracle.com, xfs@oss.sgi.com On 04/20/2010 09:36 AM, Wengang Wang wrote: > Hi experts, > > Do we support using a file as log device? > If no, it's strange that we support running xfs on a file but don't support log > file. > If yes, it fails at mount. > > [root@desk test-xfsprogs]# mkfs.xfs > -llogdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile,size=32768b > /dev/sda10 -f > meta-data=/dev/sda10 isize=256 agcount=4, agsize=1250558 > blks > = sectsz=512 attr=2 > data = bsize=4096 blocks=5002231, imaxpct=25 > = sunit=0 swidth=0 blks > naming =version 2 bsize=4096 ascii-ci=0 > log =/root/test-xfsprogs/test-xfsprogs-tmp/imagefile bsize=4096 > blocks=32768, version=2 > = sectsz=512 sunit=0 blks, lazy-count=0 > realtime =none extsz=4096 blocks=0, rtextents=0 > [root@desk test-xfsprogs]# mount > -ologdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile /dev/sda10 /xfs > mount: the kernel does not recognize /dev/sda10 as a block device > (maybe `insmod driver'?) Well, -o logdev=$BLAH sets up m_logname with that value in the mount point, and xfs_open_devices() then tries: if (mp->m_logname) { error = xfs_blkdev_get(mp, mp->m_logname, &logdev); which eventually does open_bdev_exclusive(name, FMODE_READ|FMODE_WRITE, mp); /** * open_bdev_exclusive - open a block device by name and set it up for use * * @path: special file representing the block device * @mode: FMODE_... combination to pass be used * @holder: owner for exclusion * * Open the blockdevice described by the special file at @path, claim it * for the @holder. */ ... this is all in kernelspace, which has no notion of what /root/test-xfsprogs/test-xfsprogs-tmp/imagefile might be. You'll need to use a devicename that open_bdev_exclusive() can understand (like /dev/loop0, as suggested) -Eric _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs