From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [PATCH] btrfs: Add a new mount option to grow the FS to the limit of the device Date: Wed, 4 Aug 2010 09:30:51 -0400 Message-ID: <20100804133051.GF16630@think> References: <4C5684D8.4080702@samsung.com> <20100803114947.GO16630@think> <4C595053.5030305@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-btrfs@vger.kernel.org, kyungmin.park@samsung.com To: Donggeun Kim Return-path: In-Reply-To: <4C595053.5030305@samsung.com> List-ID: On Wed, Aug 04, 2010 at 08:34:43PM +0900, Donggeun Kim wrote: > Chris Mason wrote: > > On Mon, Aug 02, 2010 at 05:42:00PM +0900, Donggeun Kim wrote: > >> In some cases, resizing a file system to the maximum device size is required. > >> When flashing a file system image to a block device, > >> the file system does not fit into the block device's size. > >> Currently, executing 'btrfsctl' application is the only way > >> to grow the file system to the limit of the device. > >> If the mount option which alters the device size of a file system > >> to the limit of the device is supported, > >> it can be useful regardless of the existence of 'btrfsctl' program. > >> This patch allows the file system to grow to the maximum size of the device > >> on mount time. > >> The new mount option name is 'maxsize'. > > > > I think this is a very useful feature, but could you please change the > > patch to allow controlling which device is resized? > > > > The ioctl allows you to pass in a device number (where the number comes > > from btrfs-show) > > > > Thanks! > > > > -chris > > > I'm sorry not to fully understand your comment. > Do you mean that device file name for being resized is specified after 'maxsize' mount option? > e.g) #mount -o maxsize=/dev/sda1 ... In the resize ioctl you can pass a device number, something like 2:max, which allows you to say make device #2 the full size of the device. btrfs-show can be used to find the correct device number for a given disk. We don't use the device name because the scan might have found a different device name to tie into the FS. Thanks, Chris