From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f171.google.com (mail-qk1-f171.google.com [209.85.222.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E495C21D3E4 for ; Fri, 17 Apr 2026 06:46:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776408394; cv=none; b=kwciA96ymVmfSgyYeKhGcXLtL4UA3UwJ85GpZ3YwfDVd3o4RBXaRb4QCZk0V0/5HDW5rdgGZmejs1+7n3dEmgBlAiJlq35EJ7CDoM6zMIw02RntmFrA27GHWrL80qLTc4EYp4uxvanIYiznX8I7pkZDVJ8T7RxUwtpwu/R8ODz4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776408394; c=relaxed/simple; bh=d4PpKCk3+cY+Ia63Uy2Vt+eoNLKg4rm4l23ANxaSUh8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=laTxqn5T4OEAKyZFc3524fQc1qktFdvjQiPEfXJvpBMa1/zZg4mUF0UyaOGxVEZrZIkiM/lAMP9tq+TSC1cRIjafvSFzTn+28iD3zHzKKZA54kMtl+6V54WH5t9dQhSxQu9OzPbwsVIy8ecgLeMlTZHQcs4JHHNTMvrH1GBQew0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=G6TWVyi7; arc=none smtp.client-ip=209.85.222.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="G6TWVyi7" Received: by mail-qk1-f171.google.com with SMTP id af79cd13be357-8d67a483d3eso37255385a.1 for ; Thu, 16 Apr 2026 23:46:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1776408392; x=1777013192; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=hhIjuJ3A3M20AFrPa5BfGVCAhbvvigIUz2GsEPa7gR8=; b=G6TWVyi7A+bojIeIPu6SwEfEYSmy3x7RRUApMxRyyuVrRZ1cHPp+Ni1hEoNJF7O4G5 BVaj81i+xGeRdkhdmTeChTdi/FzS8fK+wTz1W18hSpNyTc/FBIGpU60ilWXAPVtPuZ8R P2ruTgGTk+Zo0DZdo9wZBo330WAdwdhBt/4xUpWzvBu/BH7Sd5FiWESWJiAZu3ibSl7v KqB7jbhVuKjavGYk9zC2EebvCD4GoJDHEwBI+kB0V0CNlviVK0UXgIDHvNaQTRqKhihX 1aZJHYnG0lnlEGhH8HgAT7aHfRc6mB/rA2CSza3Kr+gTiz7OsROULxfSS46qC7ZsG2SS lpOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776408392; x=1777013192; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=hhIjuJ3A3M20AFrPa5BfGVCAhbvvigIUz2GsEPa7gR8=; b=kWFRvlSKNeHyUCr+fvl4HoxlNv1AQJm6Vxkqq6iJZXwhyceQ7cLLw6BP9WUDjkrw0m OSXVj8yscUcA4606MAuR9UkOVnYm2FAuUrW2grTuU+6RdO84RM3LkvGi5xwA7O7bL9QU E6cQq4mgbWCBk/t1E9sqEC3JZARTrrhoCaWuZxBOxPURq8OVw+sWEXhwV0Iuf4MyBs+0 Wf1KhFGaAaiUgkgdFj08KLpeHub8fE/jq0jCPV4ioi1qgLtsSgpp2HmfNja8vGbzexsU /BB1kFtfsdVdi0jsOjwsbBPTh0PYjdhtXdI6LIXe2irofiAcRB1UY3v/GlIzCd+66Fi0 FMQw== X-Forwarded-Encrypted: i=1; AFNElJ8i15KMzjDHU24dM1u/B/krFYiOn2gVO4ULwqDzHxlygZr1ZvlcSAaxe/PnXGu05k2u+97qtTJ2xR8=@vger.kernel.org X-Gm-Message-State: AOJu0YzEkzQoRL6VF9JWqRLopqfJQEbHMJlOK7/sCaPK4vGXhA/2k+Gu SFLh2BnCQz/xocAolkhsWNYYZIHe5yq52K9PeSMX81LCdnmJhS48D+L+xbKAUL2k0zw= X-Gm-Gg: AeBDietIXRoZkhRa6GUGk4vKcrM42dFGeF4FE9e+6ExQ0BzdqESkoRsOsGZOdwcaL+K Uk0CsMgkBxhTNlfb8Ypp1LyqVja0VUgEocrA+RLKfyRjDclbq/HBkApV7N02nkwOK7uSFkBxj17 jbeAudlqLFGwikpm7ijiukqESmUEUo9XoCg90wLhX0XfBg+hBiBZ8c9+jB87f1SXAF4KxKbuLJL xTDYInISep3xYrif/Rdme91cBmMgH/HL++B7OoXUgezWEYNa/0ktzGJfQZUY5+6wzCeMop6qc+D uPPQHQV7863yrFkzFbjKBcMRra2a/huI6z2LUOXehFNEMovZ76A68aV9ftop7qWq+Lf8aYzcYcg t3m4V6Wtr9OmgdQ5gIlLEUsLNOzgBOCK9DL2KvCsiBnvlohWhEZsnQ0l6sBRLUt49I6oCSK3xiu 3AJJOwW+OsBGufCQziH1oY2FTfPerJfLws+JhZ2OI3yYRJ8CG+ufwMnh/EabFrd/NsL+vw9ZpA5 7iNWhbVsMhEap47hW4DZTAscRa89fg= X-Received: by 2002:a05:620a:4690:b0:8cd:92c5:b3e7 with SMTP id af79cd13be357-8e790407b72mr203408385a.18.1776408391906; Thu, 16 Apr 2026 23:46:31 -0700 (PDT) Received: from gourry-fedora-PF4VCD3F (pool-108-18-109-80.washdc.ftas.verizon.net. [108.18.109.80]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8e7d93c2fffsm42616985a.36.2026.04.16.23.46.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Apr 2026 23:46:30 -0700 (PDT) Date: Fri, 17 Apr 2026 02:46:27 -0400 From: Gregory Price To: Joanne Koong Cc: John Groves , "Darrick J. Wong" , Miklos Szeredi , Bernd Schubert , John Groves , Dan Williams , Bernd Schubert , Alison Schofield , John Groves , Jonathan Corbet , Shuah Khan , Vishal Verma , Dave Jiang , Matthew Wilcox , Jan Kara , Alexander Viro , David Hildenbrand , Christian Brauner , Randy Dunlap , Jeff Layton , Amir Goldstein , Jonathan Cameron , Stefan Hajnoczi , Josef Bacik , Bagas Sanjaya , Chen Linxuan , James Morse , Fuad Tabba , Sean Christopherson , Shivank Garg , Ackerley Tng , Aravind Ramesh , Ajay Joshi , "venkataravis@micron.com" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nvdimm@lists.linux.dev" , "linux-cxl@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , djbw@kernel.org Subject: Re: [PATCH V10 00/10] famfs: port into fuse Message-ID: References: <20260414185740.GA604658@frogsfrogsfrogs> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Apr 16, 2026 at 06:24:02PM -0700, Joanne Koong wrote: > On Thu, Apr 16, 2026 at 1:14 PM Gregory Price wrote: > > > > I worry that this discussion is going to turn towards implementing a > > solution grounded in parsing arbitrary formats and how to store them, > > and that is completely detached from why FAMFS went this route in the > > first place. > > > > I question whether the actual issue here lies in the interface APPEARING > > more general purpose than it actually is - and therefore inviting > > attempts to over-genericize it. > > Would you mind clarifying this part? Are you saying that the interface > and logic is *already* generic and usable for other dax-backed > servers, just that everything is *named* famfs but it's not really > famfs specific? Yes. If you just find/replace "famfs" with "dax_iomap", the structures here don't really seem all *that* crazy specific - they're just optimized for memory speeds instead of I/O. There is a circular nature to this - FAMFS figured it out first, in what we think is a reasonably generic way, but we can't know for sure. John, Dan, and Darrick have all proposed reasonable ways to hedge against the obvious fact the interface will not be perfect - which incorporates your BPF proposal along with a reasonably straight forward deprecation path that's not always possible in other arenas. All that while solving a real (and novel) problem. That's actually pretty damn cool. I would urge you to consider these proposals earnestly. ~Gregory