From dfeab2e95a75a424adf39992ac62dcb9e9517d4a Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Thu, 14 Oct 2021 16:10:10 +0800 Subject: erofs: add multiple device support In order to support multi-layer container images, add multiple device feature to EROFS. Two ways are available to use for now: - Devices can be mapped into 32-bit global block address space; - Device ID can be specified with the chunk indexes format. Note that it assumes no extent would cross device boundary and mkfs should take care of it seriously. In the future, a dedicated device manager could be introduced then thus extra devices can be automatically scanned by UUID as well. Link: https://lore.kernel.org/r/20211014081010.43485-1-hsiangkao@linux.alibaba.com Reviewed-by: Chao Yu Reviewed-by: Liu Bo Signed-off-by: Gao Xiang --- fs/erofs/Kconfig | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) (limited to 'fs/erofs/Kconfig') diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig index 14b747026742..addfe608d08e 100644 --- a/fs/erofs/Kconfig +++ b/fs/erofs/Kconfig @@ -6,16 +6,22 @@ config EROFS_FS select FS_IOMAP select LIBCRC32C help - EROFS (Enhanced Read-Only File System) is a lightweight - read-only file system with modern designs (eg. page-sized - blocks, inline xattrs/data, etc.) for scenarios which need - high-performance read-only requirements, e.g. Android OS - for mobile phones and LIVECDs. + 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 fixed-sized output compression support, - which improves storage density, keeps relatively higher - compression ratios, which is more useful to achieve high - performance for embedded devices with limited memory. + It also provides fixed-sized output compression support in order to + improve storage density as well as keep relatively higher compression + ratios and implements in-place decompression to reuse the file page + for compressed data temporarily with proper strategies, which is + quite useful to ensure guaranteed end-to-end runtime decompression + performance under extremely memory pressure without extra cost. + + See the documentation at + for more details. If unsure, say N. -- cgit v1.2.3