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path: root/fs/erofs/compress.h
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2024-03-10erofs: refine managed cache operations to foliosGao Xiang1-7/+0
Convert erofs_try_to_free_all_cached_pages() and z_erofs_cache_release_folio(). Besides, erofs_page_is_managed() is moved to zdata.c and renamed as erofs_folio_is_managed(). Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20240305091448.1384242-6-hsiangkao@linux.alibaba.com
2024-01-27erofs: relaxed temporary buffers allocation on readaheadChunhai Guo1-3/+2
Even with inplace decompression, sometimes very few temporary buffers may be still needed for a single decompression shot (e.g. 16 pages for 64k sliding window or 4 pages for 16k sliding window). In low-memory scenarios, it would be better to try to allocate with GFP_NOWAIT on readahead first. That can help reduce the time spent on page allocation under durative memory pressure. Here are detailed performance numbers under multi-app launch benchmark workload [1] on ARM64 Android devices (8-core CPU and 8GB of memory) running a 5.15 LTS kernel with EROFS of 4k pclusters: +----------------------------------------------+ | LZ4 | vanilla | patched | diff | |----------------+---------+---------+---------| | Average (ms) | 3364 | 2684 | -20.21% | [64k sliding window] |----------------+---------+---------+---------| | Average (ms) | 2079 | 1610 | -22.56% | [16k sliding window] +----------------------------------------------+ The total size of system images for 4k pclusters is almost unchanged: (64k sliding window) 9,117,044 KB (16k sliding window) 9,113,096 KB Therefore, in addition to switch the sliding window from 64k to 16k, after applying this patch, it can eventually save 52.14% (3364 -> 1610) on average with no memory reservation. That is particularly useful for embedded devices with limited resources. [1] https://lore.kernel.org/r/20240109074143.4138783-1-guochunhai@vivo.com Suggested-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Chunhai Guo <guochunhai@vivo.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Reviewed-by: Yue Hu <huyue2@coolpad.com> Link: https://lore.kernel.org/r/20240126140142.201718-1-hsiangkao@linux.alibaba.com
2023-10-31erofs: simplify compression configuration parserGao Xiang1-0/+6
Move erofs_load_compr_cfgs() into decompressor.c as well as introduce a callback instead of a hard-coded switch for each algorithm for simplicity. Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20231022130957.11398-1-xiang@kernel.org
2023-08-11erofs: DEFLATE compression supportGao Xiang1-0/+2
Add DEFLATE compression as the 3rd supported algorithm. DEFLATE is a popular generic-purpose compression algorithm for quite long time (many advanced formats like gzip, zlib, zip, png are all based on that) as Apple documentation written "If you require interoperability with non-Apple devices, use COMPRESSION_ZLIB. [1]". Due to its popularity, there are several hardware on-market DEFLATE accelerators, such as (s390) DFLTCC, (Intel) IAA/QAT, (HiSilicon) ZIP accelerator, etc. In addition, there are also several high-performence IP cores and even open-source FPGA approches available for DEFLATE. Therefore, it's useful to support DEFLATE compression in order to find a way to utilize these accelerators for asynchronous I/Os and get benefits from these later. Besides, it's a good choice to trade off between compression ratios and performance compared to LZ4 and LZMA. The DEFLATE core format is simple as well as easy to understand, therefore the code size of its decompressor is small even for the bootloader use cases. The runtime memory consumption is quite limited too (e.g. 32K + ~7K for each zlib stream). As usual, EROFS ourperforms similar approaches too. Alternatively, DEFLATE could still be used for some specific files since EROFS supports multiple compression algorithms in one image. [1] https://developer.apple.com/documentation/compression/compression_algorithm Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20230810154859.118330-1-hsiangkao@linux.alibaba.com
2023-05-29erofs: fold in z_erofs_decompress()Yue Hu1-2/+1
No need this helper since it's just a simple wrapper for decompress method and only one caller. So, let's fold in directly instead. Signed-off-by: Yue Hu <huyue2@coolpad.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20230426084449.12781-1-zbestahu@gmail.com Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2022-07-22erofs: introduce multi-reference pclusters (fully-referenced)Gao Xiang1-1/+1
Let's introduce multi-reference pclusters at runtime. In details, if one pcluster is requested by multiple extents at almost the same time (even belong to different files), the longest extent will be decompressed as representative and the other extents are actually copied from the longest one in one round. After this patch, fully-referenced extents can be correctly handled and the full decoding check needs to be bypassed for partial-referenced extents. Acked-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20220715154203.48093-17-hsiangkao@linux.alibaba.com
2021-12-29erofs: introduce z_erofs_fixup_insizeGao Xiang1-1/+3
To prepare for the upcoming ztailpacking feature, introduce z_erofs_fixup_insize() and pageofs_in to wrap up the process to get the exact compressed size via zero padding. Link: https://lore.kernel.org/r/20211228054604.114518-3-hsiangkao@linux.alibaba.com Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2021-10-25erofs: get rid of ->lru usageGao Xiang1-6/+5
Currently, ->lru is a way to arrange non-LRU pages and has some in-kernel users. In order to minimize noticable issues of page reclaim and cache thrashing under high memory presure, limited temporary pages were all chained with ->lru and can be reused during the request. However, it seems that ->lru could be removed when folio is landing. Let's use page->private to chain temporary pages for now instead and transform EROFS formally after the topic of the folio / file page design is finalized. Link: https://lore.kernel.org/r/20211022090120.14675-1-hsiangkao@linux.alibaba.com Cc: Matthew Wilcox <willy@infradead.org> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2021-10-19erofs: lzma compression supportGao Xiang1-0/+16
Add MicroLZMA support in order to maximize compression ratios for specific scenarios. For example, it's useful for low-end embedded boards and as a secondary algorithm in a file for specific access patterns. MicroLZMA is a new container format for raw LZMA1, which was created by Lasse Collin aiming to minimize old LZMA headers and get rid of unnecessary EOPM (end of payload marker) as well as to enable fixed-sized output compression, especially for 4KiB pclusters. Similar to LZ4, inplace I/O approach is used to minimize runtime memory footprint when dealing with I/O. Overlapped decompression is handled with 1) bounced buffer for data under processing or 2) extra short-lived pages from the on-stack pagepool which will be shared in the same read request (128KiB for example). Link: https://lore.kernel.org/r/20211010213145.17462-8-xiang@kernel.org Acked-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2021-10-17erofs: get compression algorithms directly on mappingGao Xiang1-5/+0
Currently, z_erofs_map_blocks_iter() returns whether extents are compressed or not, and the decompression frontend gets the specific algorithms then. It works but not quite well in many aspests, for example: - The decompression frontend has to deal with whether extents are compressed or not again and lookup the algorithms if compressed. It's duplicated and too detailed about the on-disk mapping. - A new secondary compression head will be introduced later so that each file can have 2 compression algorithms at most for different type of data. It could increase the complexity of the decompression frontend if still handled in this way; - A new readmore decompression strategy will be introduced to get better performance for much bigger pcluster and lzma, which needs the specific algorithm in advance as well. Let's look up compression algorithms in z_erofs_map_blocks_iter() directly instead. Link: https://lore.kernel.org/r/20211008200839.24541-2-xiang@kernel.org Reviewed-by: Chao Yu <chao@kernel.org> Reviewed-by: Yue Hu <huyue2@yulong.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2021-06-07erofs: clean up file headers & footersGao Xiang1-2/+0
- Remove my outdated misleading email address; - Get rid of all unnecessary trailing newline by accident. Link: https://lore.kernel.org/r/20210602160634.10757-1-xiang@kernel.org Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2020-12-09erofs: force inplace I/O under low memory scenarioGao Xiang1-0/+3
Try to forcely switch to inplace I/O under low memory scenario in order to avoid direct memory reclaim due to cached page allocation. Link: https://lore.kernel.org/r/20201209123717.12430-1-hsiangkao@aol.com Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2020-12-08erofs: get rid of magical Z_EROFS_MAPPING_STAGINGGao Xiang1-13/+38
Previously, we played around with magical page->mapping for short-lived temporary pages since we need to identify different types of pages in the same pcluster but both invalidated and short-lived temporary pages can have page->mapping == NULL. It was considered as safe because that temporary pages are all non-LRU / non-movable pages. This patch tends to use specific page->private to identify short-lived pages instead so it won't rely on page->mapping anymore. Details are described in "compress.h" as well. Link: https://lore.kernel.org/r/20201208095834.3133565-1-hsiangkao@redhat.com Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2020-08-03erofs: Replace HTTP links with HTTPS onesAlexander A. Klimov1-1/+1
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Reviewed-by: Gao Xiang <hsiangkao@redhat.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200713130944.34419-1-grandmaster@al2klimov.de Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
2019-08-24erofs: move erofs out of stagingGao Xiang1-0/+60
EROFS filesystem has been merged into linux-staging for a year. EROFS is designed to be a better solution of saving extra storage space with guaranteed end-to-end performance for read-only files with the help of reduced metadata, fixed-sized output compression and decompression inplace technologies. In the past year, EROFS was greatly improved by many people as a staging driver, self-tested, betaed by a large number of our internal users, successfully applied to almost all in-service HUAWEI smartphones as the part of EMUI 9.1 and proven to be stable enough to be moved out of staging. EROFS is a self-contained filesystem driver. Although there are still some TODOs to be more generic, we have a dedicated team actively keeping on working on EROFS in order to make it better with the evolution of Linux kernel as the other in-kernel filesystems. As Pavel suggested, it's better to do as one commit since git can do moves and all histories will be saved in this way. Let's promote it from staging and enhance it more actively as a "real" part of kernel for more wider scenarios! Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Pavel Machek <pavel@denx.de> Cc: David Sterba <dsterba@suse.cz> Cc: Amir Goldstein <amir73il@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J . Wong <darrick.wong@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Richard Weinberger <richard@nod.at> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Chao Yu <yuchao0@huawei.com> Cc: Miao Xie <miaoxie@huawei.com> Cc: Li Guifu <bluce.liguifu@huawei.com> Cc: Fang Wei <fangwei1@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Link: https://lore.kernel.org/r/20190822213659.5501-1-hsiangkao@aol.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>