From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [PATCHv3] UBI: new module ubiblk: block layer on top of UBI Date: Tue, 06 Sep 2011 07:10:03 +0300 Message-ID: <1315282208.19067.24.camel@sauron> References: <1308922482-14967-1-git-send-email-david.wagner@free-electrons.com> <201108241823.20904.arnd@arndb.de> <1314256010.18988.18.camel@sauron> <201108251712.40894.arnd@arndb.de> <1315280704.19067.14.camel@sauron> Reply-To: dedekind1@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=subject:from:reply-to:to:cc:date:in-reply-to:references :content-type:x-mailer:content-transfer-encoding:message-id :mime-version; bh=DaCSirDznfwla2LxOC+lEYvgeV3WC6hnjuoYW+L0ixs=; b=CsU2uVCGnY5u+KRFKEwm+ry+s1EElJXV46oCyQupIruLXzWsN4+jIH+LoIJ/m4rLOE bm8zFfbTssQTJRdhmzovoq8wCC9dCZ9To2gHzJdpvSIbC59CsGiAoKk6LkPGvCrLcrsT XK9w8jy7Ge5rP+1GnzMmCxMua6BFrPPqpb1y0= In-Reply-To: <1315280704.19067.14.camel@sauron> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+gldm-linux-mtd-36=gmane.org@lists.infradead.org To: Arnd Bergmann Cc: linux-embedded , david.wagner@free-electrons.com, lkml , linux-mtd , Tim Bird , David Woodhouse On Tue, 2011-09-06 at 06:44 +0300, Artem Bityutskiy wrote: > > It's not a dummy bus, in this approach it would be a the bus that gets > > used by all ubiblk devices, which is a very common concept by itself. > > It's more like the classic understanding of a 'device class' that Greg > > wants to see get replaced by bus_types in the kernel. > > Yes, this sounds OK. Although UBI already has notifiers, so we could > just add 2 more events. Hmm, with notifications the error handling becomes a problem - we want the ioctls for creating/removing the block device to be synchronous, and, should an error occur, we want to return the error code to the user-space. So the existing notifications mechanism does not work well. Not sure about the bus approach - David, could you take a look at it please? If we can handle errors there - then we could indeed re-use the UBI control device. We could even re-use the ioctl data structures for UBI volumes creation/removal - we have plenty of space there reserved for future extensions. -- Best Regards, Artem Bityutskiy ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/