From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from top.free-electrons.com ([176.31.233.9] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XBbHk-00087i-6W for linux-mtd@lists.infradead.org; Mon, 28 Jul 2014 03:07:38 +0000 Date: Mon, 28 Jul 2014 00:06:16 -0300 From: Ezequiel Garcia To: Richard Weinberger Subject: Re: Using UBIFS as an FTL Message-ID: <20140728030616.GA1545@arch.cereza> References: <53D2EB45.9060302@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Cc: Daniel Ehrenberg , "linux-mtd@lists.infradead.org" , artem.bityutskiy@linux.intel.com, hujianyang List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 27 Jul 09:20 AM, Richard Weinberger wrote: > On Sat, Jul 26, 2014 at 1:41 AM, hujianyang wrote: > > On 2014/7/26 2:21, Daniel Ehrenberg wrote: > >> - loopback-mounting a file on ubifs--From skimming the code, it looks > >> to me like ubifs uses some nice datastructures to handle writes within > >> a file without doing read-modify-writes all the time as ubiblock > >> forces. ubifs authors/maintainers, do you see any downside to using > >> ubifs this way? > > > > This way seems most easily to realize. Synchronize the loop file and > > maybe you will never worry about power cut. > > > > How about using UBI-layer and writing a new block driver to handle > > bio? This driver should care about which leb on the flash has data > > and other thing else(I don't have a clear idea now). The 'leb_change' > > ops in UBI-layer maybe helpful for in-place update and atomic write. > > But This way is harder than using a loop file. > > Instead of adding another UBI block layer, please integrate such functionality > in Ezequiel's UBI block. > Daniel already mentioned it didn't git his needs. Quoting him: """ - ubiblock--the read-modify-write sounds unacceptable to me, even if wear leveling and atomicity are handled. - Some coworkers have suggested a new effort to build a new block device, but that that's a huge project and takes a long time to get right. """ Daniel: Maybe you can mention why you believe it's unacceptable? -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com