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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=VX8jDzQJ; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=172.234.252.31; helo=sea.source.kernel.org; envelope-from=chao@kernel.org; receiver=lists.ozlabs.org) Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) (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 4ffTDM6rW2z2ySb for ; Mon, 23 Mar 2026 20:59:47 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 55C06436CA; Mon, 23 Mar 2026 09:59:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6DCD1C4CEF7; Mon, 23 Mar 2026 09:59:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774259985; bh=o9VDcVaeOW+9PxAISKA8BbwHP5JjMc2drei/sa5NuKk=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=VX8jDzQJUG5re5L6rbV2/LwwAYcZZCVfU3aSXZsizRDBKRzrFzpPz1d+kWdQKZpAt ij/dnMCc0iX/thIVzwGEq0QjpkdvA2jRYV284XEjAIPr2w8j/gWSXwKnEbtKfjjlPo zW5Oyt8JmdnhBI2C6XI2rn0ahpi0UvF0S1ucCzki3Uiv7vaqtWT5GwTxr7Ke7ZA+Mp 1+n6UP2SpVZvJyfnUWp9kRMTIghaxfPikBGqrWoULvf2UOF+LHL4FWAmmkN4YCoQkf a7K8lf0kNreH68/0nh2HqYtQeTxq1/ALob4Ax62kc2tsDIlxwbusqowdAIZuopim8a gO3A/TRBV//Dw== Message-ID: <927c52ee-24b5-4b8f-98ee-3a18f13fa8b5@kernel.org> Date: Mon, 23 Mar 2026 17:59:42 +0800 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 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, LKML Subject: Re: [PATCH] erofs: update the Kconfig description To: Gao Xiang , linux-erofs@lists.ozlabs.org References: <20260323094857.2187994-1-hsiangkao@linux.alibaba.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260323094857.2187994-1-hsiangkao@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/23/26 17:48, Gao Xiang wrote: > Refine the description to better highlight its features and use cases. > > In addition, add instructions for building it as a module and clarify > the compression option. > > Signed-off-by: Gao Xiang > --- > fs/erofs/Kconfig | 45 ++++++++++++++++++++++++++++++--------------- > 1 file changed, 30 insertions(+), 15 deletions(-) > > diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig > index a9f645f57bb2..9489ed8ad95b 100644 > --- a/fs/erofs/Kconfig > +++ b/fs/erofs/Kconfig > @@ -16,22 +16,36 @@ config EROFS_FS > select ZLIB_INFLATE if EROFS_FS_ZIP_DEFLATE > select ZSTD_DECOMPRESS if EROFS_FS_ZIP_ZSTD > help > - EROFS (Enhanced Read-Only File System) is a lightweight read-only > - file system with modern designs (e.g. no buffer heads, inline > - xattrs/data, chunk-based deduplication, multiple devices, etc.) for > - scenarios which need high-performance read-only solutions, e.g. > - smartphones with Android OS, LiveCDs and high-density hosts with > - numerous containers; > - > - It also provides transparent compression and deduplication support to > - improve storage density and maintain relatively high compression > - ratios, and it implements in-place decompression to temporarily reuse > - page cache for compressed data using proper strategies, which is > - quite useful for ensuring guaranteed end-to-end runtime decompression > + EROFS (Enhanced Read-Only File System) is a modern, lightweight, > + secure read-only filesystem for various use cases, such as immutable > + system images, container images, application sandboxes, and datasets. > + > + EROFS uses a flexible, hierarchical on-disk design so that features > + can be enabled on demand: the core on-disk format is block-aligned in > + order to perform optimally on all kinds of devices, including block > + and memory-backed devices; the format is easy to parse and has zero > + metadata redundancy, unlike generic filesystems, making it ideal for > + for filesytem auditing and remote access; inline data, random-access duplicated 'for'? otherwise, looks good to me. Reviewed-by: Chao Yu Thanks, > + friendly directory data, inline/shared extended attributes and > + chunk-based deduplication ensure space efficiency while maintaining > + high performance. > + > + Optionally, it supports multiple devices to reference external data, > + enabling data sharing for container images. > + > + It also has advanced encoded on-disk layouts, particularly for data > + compression and fine-grained deduplication. It utilizes fixed-size > + output compression to improve storage density while keeping relatively > + high compression ratios. Furthermore, it implements in-place > + decompression to reuse file pages to keep compressed data temporarily > + with proper strategies, which ensures guaranteed end-to-end runtime > performance under extreme memory pressure without extra cost. > > - See the documentation at > - and the web pages at for more details. > + For more details, see the web pages at > + and the documentation at . > + > + To compile EROFS filesystem support as a module, choose M here. The > + module will be called erofs. > > If unsure, say N. > > @@ -105,7 +119,8 @@ config EROFS_FS_ZIP > depends on EROFS_FS > default y > help > - Enable transparent compression support for EROFS file systems. > + Enable EROFS compression layouts so that filesystems containing > + compressed files can be parsed by the kernel. > > If you don't want to enable compression feature, say N. >