From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f177.google.com (mail-qt1-f177.google.com [209.85.160.177]) (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 9071B1DEFE8 for ; Thu, 14 Aug 2025 14:37:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755182233; cv=none; b=Gx/ZQGL1rzIEqJ6/Nka+nXrD9ukufAFP34HYmhbaDi6D8ZpHdadBitGyXOE0LourM5AeRhgsSrIITXUvCXU1of//yAk/Nl26+27IDrzMv29jVWptM61ZyT0skQ7lON7Ss/PW95h0Jc2jDNUqTNS8fWkOAtjB5+aaWmr1Cux3AT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755182233; c=relaxed/simple; bh=NOpPaMEGwARq4CHAFNBf771d9jPnS5ZeE6rfKhlvASU=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=h2Ykeo10mNwrmh/+gQIPLI0pDWgpj6o7QNQwBunwnae1QCfR5KGZZKYGCIa7mx3eSeovkg2HHjcIRn3HNZBChKXBW7azlmp4mcBqInbWzd9rCSk2aCfS4ijyS+M/gmZy8+zeo8Xt1pCsehT8hX9R5695kjfax4tfrjsOR2LHnIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=szeredi.hu; spf=pass smtp.mailfrom=szeredi.hu; dkim=pass (1024-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b=KQNJjeAf; arc=none smtp.client-ip=209.85.160.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=szeredi.hu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=szeredi.hu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="KQNJjeAf" Received: by mail-qt1-f177.google.com with SMTP id d75a77b69052e-4b109919a09so13204251cf.0 for ; Thu, 14 Aug 2025 07:37:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; t=1755182230; x=1755787030; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=thFJCyGfhvQRRqY0DjMQa3Qo17IKtZ1G40gUR9k6ews=; b=KQNJjeAfSoSwUDRw80154oLg3NjJYeTUwz6KXDBkYfQTu8vynYQjQRzggbRtxTurRv L1oI7K7IHGucMXWSh43/r5zPlnon/WpknKv47HhPAwiY1H/gITEGb+I8a/WvoKgR8SpP qeUdiB/FilITBvEDt1dY4jA5A58cLYBl/doa0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755182230; x=1755787030; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=thFJCyGfhvQRRqY0DjMQa3Qo17IKtZ1G40gUR9k6ews=; b=ktMoHO70kWs94SgcsaEU61B3cBkW7AfdZBtCmSvoNRMSKyKV2RwPO7HSYGOPgy1iZu W+R9HXQq0unmgTMJ7cdpk0LL1Q+d3LcfJYld64F7mdPI/He2RPmGf8MsuD/lqyWH4lLr 6mxrUNWkoeGXCTGk53NR8Ag2HjTX/ebujokD4jPeopLcSOBPsBXMdfYHO3xUSAVRjV1s TJ9oinZXw+uBfmheArFMWm3oLr0mYvVyzEquwenK4omb+UAuJlFww/PjQu90J6vQfKRw 2aRAFp+lafQP/8DlNeXKIsST9HmZJwPHQC+XJgSO5hXzscWyr8Mslb1W7Wq1VX0Baxnh 8LYQ== X-Forwarded-Encrypted: i=1; AJvYcCX9I1oe+tPcIWWgOd1mh9VROgL7EeT4d6e72YRUY81z+7G7seIPMmVUJ+C5SQ9d5DKj0DFzcUgDvrk=@vger.kernel.org X-Gm-Message-State: AOJu0Yz4BfYKitizN2Vh4OWAh5vFGkBfLpvyX1W8uSwkWcVnHnYXEy7m soSTIfnua2ftCBMjmrQX0dTkCQ7ZNC+VUE92LgU/Sb0WM6pClqLPyCslMbChMSdcU5NaoIIP2w0 X3U7kbvhuno9JLP2Eg20iidtpZdC/bPKmSr3b4wp+kg== X-Gm-Gg: ASbGncsXQO0CNM4YuHy1XhJnj1AtzXQruSz48hczKJScFv79XJxlLOdbYKwOWG4oRSZ tsNxT+OuqgYcQj01Vpbb3koWJ2k3+wtlabZkGaZ/MJJE8H6/clWkWndWzDXsrCZmNyOPrpGyjFM fSfzCaBWZ9+Pufu/IMLzQXGl1qe60KToQUnLgzRDRWcDWZGoDbXsqJUO8euHFsm9Zziv3lY3o1+ IZz X-Google-Smtp-Source: AGHT+IHnfRI5xHzwEiwbnlj4w/zFMDDNEEaatcq1mpqAAB2GV7mMF1beVsw/Q/x3FPL39V74ikfbsx8wh3qug5aBccg= X-Received: by 2002:a05:622a:1926:b0:4af:15e5:e84 with SMTP id d75a77b69052e-4b10aae7b12mr50528031cf.42.1755182230192; Thu, 14 Aug 2025 07:37:10 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250703185032.46568-1-john@groves.net> <20250703185032.46568-13-john@groves.net> In-Reply-To: From: Miklos Szeredi Date: Thu, 14 Aug 2025 16:36:57 +0200 X-Gm-Features: Ac12FXxrfsSu-05pCnMumsCzYXADqTJ2OFTZfF8uQPidyp6kmWUcoLNSx-lr5VI Message-ID: Subject: Re: [RFC V2 12/18] famfs_fuse: Plumb the GET_FMAP message/response To: John Groves Cc: Dan Williams , Bernd Schubert , John Groves , Jonathan Corbet , Vishal Verma , Dave Jiang , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , "Darrick J . Wong" , 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 Content-Type: text/plain; charset="UTF-8" On Thu, 14 Aug 2025 at 15:36, Miklos Szeredi wrote: > I'm still hoping some common ground would benefit both interfaces. > Just not sure what it should be. Something very high level: - allow several map formats: say a plain one with a list of extents and a famfs one - allow several types of backing files: say regular and dax dev - querying maps has a common protocol, format of maps is opaque to this - maps are cached by a common facility - each type of mapping has a decoder module - each type of backing file has a module for handling I/O Does this make sense? This doesn't have to be implemented in one go, but for example GET_FMAP could be renamed to GET_READ_MAP with an added offset and size parameter. For famfs the offset/size would be set to zero/inf. I'd be content with that for now. Thanks, Miklos > > Thanks, > Miklos