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[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-cxl@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