From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF7DC20298D; Thu, 14 Aug 2025 17:19:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755191983; cv=none; b=upNQ1K216ohOiaLHDeqQ9vKnM84qTaKjMLNNrAiVcVO5GCXXHwodN9i8Vef4h2p+OWYw0+nBPWD5E7LcLlQRtydhGkct1Fj0f6l9T4xIvQw1ERUliM2mmE/gPkrwE5zmmT0ZgJhIafgAwg+FLHUezWrPVPkGWDI1SDw57PEp8pI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755191983; c=relaxed/simple; bh=IFafzpayfaPkdGpJ1GtHgExVV5V7zc9Jcmdm1ZW+Jck=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jUo8cmiUM0hO7qcB6kID3mG10bpNn+kRV46MRHjsrWLi2x+ATtZwGLmlg3oQfvS++zNpNukkTtkZKcbOjU8NNeIYAmmutsR31p4Ifj7VD4R/aLZGVh1GyBxtyOAL4dgaRuuRFETJVU2D0msnM3KqzgIFPBj4qUKhqC9eTv26kig= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dAIl1XhD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dAIl1XhD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B809C4CEED; Thu, 14 Aug 2025 17:19:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755191982; bh=IFafzpayfaPkdGpJ1GtHgExVV5V7zc9Jcmdm1ZW+Jck=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dAIl1XhD/dwGVguLT7QUA0xT3pHiwW6jTWLwC4UaCStiMSMO2wqT+QkJkc1EAy/jf VF3ifXD1d10MIhzPQMUFRxh7iC3rTbfqzctyd6ggUbYJNQ/mnJ7mXpyrxX1CKwMpU5 mXlilT2kfIFLwwfTCOwElE2xGOA7yuFyHWngfuwkELMy9K4ldkXm5bWRQZcIoAxza8 6TKjyNyQBqDMNW5fPrY8ab6mbFAl8HSsFxT54GDT39x+9B+tA0RnLessSz6OBfuhug //2QlgFN4GpBRVwpxAVAfLdejs2WPQRCsynfUANFq/k+EV67krLc8hbr3GnZ9d7tpg rRWMzT/4uJCjw== Date: Thu, 14 Aug 2025 10:19:41 -0700 From: "Darrick J. Wong" To: Miklos Szeredi Cc: John Groves , Dan Williams , Bernd Schubert , John Groves , Jonathan Corbet , Vishal Verma , Dave Jiang , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , Randy Dunlap , Jeff Layton , Kent Overstreet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, Amir Goldstein , Jonathan Cameron , Stefan Hajnoczi , Joanne Koong , Josef Bacik , Aravind Ramesh , Ajay Joshi Subject: Re: [RFC V2 14/18] famfs_fuse: GET_DAXDEV message and daxdev_table Message-ID: <20250814171941.GU7942@frogsfrogsfrogs> References: <20250703185032.46568-1-john@groves.net> <20250703185032.46568-15-john@groves.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Aug 14, 2025 at 03:58:58PM +0200, Miklos Szeredi wrote: > On Thu, 3 Jul 2025 at 20:54, John Groves wrote: > > > > * The new GET_DAXDEV message/response is enabled > > * The command it triggered by the update_daxdev_table() call, if there > > are any daxdevs in the subject fmap that are not represented in the > > daxdev_dable yet. > > This is rather convoluted, the server *should know* which dax devices > it has registered, hence it shouldn't need to be explicitly asked. > > And there's already an API for registering file descriptors: > FUSE_DEV_IOC_BACKING_OPEN. Is there a reason that interface couldn't > be used by famfs? What happens if you want to have a fuse server that hosts both famfs files /and/ backing files? That'd be pretty crazy to mix both paths in one filesystem, but it's in theory possible, particularly if the famfs server wanted to export a pseudofile where everyone could find that shadow file? --D > Thanks, > Miklos >