From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 763E6EB1043 for ; Tue, 10 Mar 2026 10:24:31 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fVVNs6fYbz3bjb; Tue, 10 Mar 2026 21:24:29 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2600:3c04:e001:324:0:1991:8:25" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1773138269; cv=none; b=gijWa/d7pt1hQSfe96HHw546SteLYjkC9HKgIBktaFnDBudEHuI3RDozrhI2UGef+9yEwuUHIX7NGMteDNzKt7qOTesxEEbnggkbPgHdFMuLpMaQ1nJ2LAuFYn72i0hBgHr/o4ywRKeDhHyD6NlgqbfiPv7p2TyXyc66pxGQyprH8HzcfWNIJDoSo5aWbATQfeUbm8oB/a5xRln6akMla1VoPXoFwZhbtJ8yAtATJpkGhfBaxs5jNuOYBPkC7jDMTLiPEWvZq6CzztKwvhhc/tsUF2XKv+hemKkF2bZPYmBcLkRctJ4qcO6fH355Z0fU2K58hMFdzVHy7+wEHWKttQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1773138269; c=relaxed/relaxed; bh=oNyg5rr0iDtSfw+Y/ml7isN2LbI/fcU2bAhuGvK67ZA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jQjblogpnse52AQRIBVtdxdRxioE0x4ApPaJr3FUtDF4HNBEvwKBS3JO5R6veBWW/yYTL0jkAha7UfyetYgDWFlDyHqn2JqylhfLx15BLtL67HncJAAPvA36N32T54yASc7dY057AwIy8CxKah/VdrOIgc1pCWj8K+nAzi4a89rvVGCeuPnFV7RZ5agHY+q+tWtwaedh2RUdghkxbsSd7qyrKPSMPu7lR08XKCHzGlfWou5Oh+ka3N1dXsUAaELbDkIFvCDPaKsus05fsCgc9jaVJeBqCtM8MvRiwtW2dnh1HBaKsXbDlo9y4LzqQmnax3X21ykrFfnMMIDHOUtu9w== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=OFRvIdC6; dkim-atps=neutral; spf=pass (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=xiang@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=OFRvIdC6; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2600:3c04:e001:324:0:1991:8:25; helo=tor.source.kernel.org; envelope-from=xiang@kernel.org; receiver=lists.ozlabs.org) Received: from tor.source.kernel.org (tor.source.kernel.org [IPv6:2600:3c04:e001:324:0:1991:8:25]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4fVVNs2Fgnz2yFY for ; Tue, 10 Mar 2026 21:24:29 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id E733360097; Tue, 10 Mar 2026 10:24:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A870C2BC87; Tue, 10 Mar 2026 10:24:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773138265; bh=nxZ9lJKi7W+un67iR2+nCzWIZ7sjXd9DTdiqKGp20R4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OFRvIdC6Aw+pes4prsTnisaAeP8tbDy5j+jWqO3MELwmzw3FLFifp09vM5pycTP5s aDZfD11hgk+o9+wQ1k4fV90J45gTQDvEr2g/8EdoFwrn39XcUqjmcZsOG7h2d23NH8 wXOk+UeUdh3tepvYPsVMC315WqYsZ4hg+/Rdc1paIKMjoXO9ecBP1quu0XXGYstEWc 0ibMnncS4pj0QnRuacDPgUEzDOK6OwSZs241A8Up0I7pGw4sAtbyuv5Qv2VbqXoWPv jIYcSsbAnKconGDsNjvGMiSYLY5CsFdXxcfVjIuQhsbPBwHaZ+gdWd/cokLJZ0HRqE e3RKN7KPxVZVA== Date: Tue, 10 Mar 2026 18:24:16 +0800 From: Gao Xiang To: Lucas Karpinski Cc: linux-erofs@lists.ozlabs.org, jcalmels@nvidia.com Subject: Re: [PATCH v2 4/5] erofs-utils: mfks: add rebuild FULLDATA for combined EROFS images Message-ID: Mail-Followup-To: Lucas Karpinski , linux-erofs@lists.ozlabs.org, jcalmels@nvidia.com References: <20260309-merge-fs-v2-0-2dd0ef53db4d@nvidia.com> <20260309-merge-fs-v2-4-2dd0ef53db4d@nvidia.com> X-Mailing-List: linux-erofs@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260309-merge-fs-v2-4-2dd0ef53db4d@nvidia.com> Hi Lucas, On Mon, Mar 09, 2026 at 12:38:20PM -0400, Lucas Karpinski wrote: > This patch introduces experimental support for merging multiple source > images in mkfs. Each source image becomes a directory directly under root > and keeps its UUID stored as a device table tag. The raw block data from > each source is copied using erofs_copy_file_range. We preserve the file > metadata and layout (FLAT_PLAIN and FLAT_INLINE). Symlink paths are handled > by reading and copy link targets. > > This does not yet support chunk-based files at this time or compressed > images. > > Signed-off-by: Lucas Karpinski Thanks for your effort, I finally get the time to look into this new feature. So you'd like to cleanly rebuild a new filesystem with given sub filesystems? I think first, yes, that is what `--clean=data` is used instead. But I think uniaddr shouldn't be used like this (uniaddr is used to give a flat mapping for multiple blobs, in addition to the device id + offset ones, which is mainly used for compressed data multi blob support), instead, I think we need to find a way to wrap up the data source into a valid vfile (so that erofs_pread can be called to get the source data) , and make erofs_mkfs_job_write_file() to write (un)compressed data from its source instead. Thanks, Gao Xiang