( Add more linuxfs folks... ) Hi,
We'd like to hear if there are potential suggestions or maybe objections of EROFS upstreaming stuffs. If any, we still have time and we can improve it in this round. As related materials mentioned before, the goal of EROFS is to save extra storage space with guaranteed end-to-end performance for read-only files, which has better performance over exist Linux compression filesystems based on fixed-sized output compression and inplace decompression. It even has better performance in a large compression ratio range compared with generic uncompressed filesystems with proper CPU-storage combinations. And we think this direction is right and we have a dedicated kernel team working on it, enough testers and beta / end users using it. EROFS has been applied to 10+ million HUAWEI mobile phones (Yes, the number is still increasing by time) and it seems like a success. It can be used in more wider scenarios. We think it's useful for Linux / Android OS community and it's the time moving out of staging. EROFS is a self-contained filesystem driver. Although there are still some TODOs, we will keep on developping / tuning EROFS with the evolution of Linux kernel as the other in-kernel filesystems. Kindly share your comments about EROFS. Thank you in advance! Thanks, Gao Xiang Changelog from v4: o rebase on Linus 5.3-rc1; o keep up with "staging: erofs: updates according to erofs-outofstaging v4" in order to get main code bit-for-bit identical with staging tree: https://lore.kernel.org/lkml/20190729065159.62378-1-gaoxian...@huawei.com/ It can also be found in git at tag "erofs_2019-07-29" at: https://git.kernel.org/pub/scm/linux/kernel/git/xiang/linux.git/ The latest fs code is available at: https://git.kernel.org/pub/scm/linux/kernel/git/xiang/linux.git/tree/fs/erofs?h=erofs-outofstaging Changelog from v3: o use GPL-2.0-only for SPDX-License-Identifier suggested by Stephen; o kill all kconfig cache strategies and turn them into mount options "cache_strategy={disable|readahead|readaround}" suggested by Ted. As the first step, cached pages can still be usable after cache is disabled by remounting, and these pages will be fallen out over time, which can be refined in the later version if some requirement is needed. Update related document as well; o turn on CONFIG_EROFS_FS_SECURITY by default suggested by David; o kill CONFIG_EROFS_FS_IO_MAX_RETRIES and fold it into code; turn EROFS_FS_USE_VM_MAP_RAM into a module parameter ("use_vmap") suggested by David. Changelog from v2: o kill sbi->dev_name and clean up all failure handling in fill_super() suggested by Al. Note that the initialzation of managed_cache is now moved after s_root is assigned since it's more preferred to iput() in .put_super() and all inodes should be evicted before the end of generic_shutdown_super(sb); o fold in the following staging patches (and thanks): staging: erofs:converting all 'unsigned' to 'unsigned int' staging: erofs: Remove function erofs_kill_sb() - However it was revoked due to erofs_kill_sb reused... staging: erofs: avoid opened loop codes staging: erofs: support bmap o move EROFS_SUPER_MAGIC_V1 from linux/fs/erofs/erofs_fs.h to include/uapi/linux/magic.h for userspace utilities. Changelog from v1: o resend the whole filesystem into a patchset suggested by Greg; o code is more cleaner, especially for decompression frontend. --8<----(original cover)---- Hi, EROFS file system has been in Linux-staging for about a year. It has been proved to be stable enough to move out of staging by 10+ millions of HUAWEI Android mobile phones on the market from EMUI 9.0.1, and it was promoted as one of the key features of EMUI 9.1 [1], including P30(pro). EROFS is a read-only file system designed to save extra storage space with guaranteed end-to-end performance by applying fixed-size output compression, inplace I/O and decompression inplace technologies [2] to Linux filesystem. In our observation, EROFS is one of the fastest Linux compression filesystem using buffered I/O in the world. It will support direct I/O in the future if needed. EROFS even has better read performance in a large CR range compared with generic uncompressed file systems with proper CPU-storage combination, which is a reason why EROFS can be landed to speed up mobile phone performance, and which can be probably used for other use cases such as LiveCD and Docker image as well. Currently EROFS supports 4k LZ4 fixed-size output compression since LZ4 is the fastest widely-used decompression solution in the world and 4k leads to unnoticable read amplification for the worst case. More compression algorithms and cluster sizes could be added later, which depends on the real requirement. More information about EROFS itself are available at: Documentation/filesystems/erofs.txt https://kccncosschn19eng.sched.com/event/Nru2/erofs-an-introduction-and-our-smartphone-practice-xiang-gao-huawei erofs-utils (mainly mkfs.erofs now) is available at git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git Preliminary iomap support has been pending in EROFS mailing list by Chao Yu. The key issue is that current iomap doesn't support tail-end packing inline data yet, it should be resolved later. Thanks to many contributors in the last year, the code is more clean and improved. We hope EROFS can be used in wider use cases so let's promote erofs out of staging and enhance it more actively. Kindly share comments about EROFS! We think EROFS is useful to community as a part of Linux upstream. Thank you very much, Gao Xiang [1] http://web.archive.org/web/20190627021241/https://consumer.huawei.com/en/emui/ [2] https://lore.kernel.org/lkml/20190624072258.28362-1-hsiang...@aol.com/ Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Alexander Viro <v...@zeniv.linux.org.uk> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Stephen Rothwell <s...@canb.auug.org.au> Cc: Theodore Ts'o <ty...@mit.edu> Cc: David Sterba <dste...@suse.cz> Cc: Amir Goldstein <amir7...@gmail.com> Cc: Christoph Hellwig <h...@infradead.org> Cc: Darrick J . Wong <darrick.w...@oracle.com> Cc: Dave Chinner <da...@fromorbit.com> Cc: Jaegeuk Kim <jaeg...@kernel.org> Cc: Jan Kara <j...@suse.cz> Cc: Chao Yu <yuch...@huawei.com> Cc: Miao Xie <miao...@huawei.com> Cc: Li Guifu <bluce.ligu...@huawei.com> Cc: Fang Wei <fangw...@huawei.com> Signed-off-by: Gao Xiang <gaoxian...@huawei.com> Gao Xiang (24): erofs: add on-disk layout erofs: add erofs in-memory stuffs erofs: add super block operations erofs: add raw address_space operations erofs: add inode operations erofs: support special inode erofs: add directory operations erofs: add namei functions erofs: support tracepoint erofs: update Kconfig and Makefile erofs: introduce xattr & posixacl support erofs: introduce tagged pointer erofs: add compression indexes support erofs: introduce superblock registration erofs: introduce erofs shrinker erofs: introduce workstation for decompression erofs: introduce per-CPU buffers implementation erofs: introduce pagevec for decompression subsystem erofs: add erofs_allocpage() erofs: introduce generic decompression backend erofs: introduce LZ4 decompression inplace erofs: introduce the decompression frontend erofs: introduce cached decompression erofs: add document Documentation/filesystems/erofs.txt | 221 +++++ fs/Kconfig | 1 + fs/Makefile | 1 + fs/erofs/Kconfig | 98 ++ fs/erofs/Makefile | 11 + fs/erofs/compress.h | 62 ++ fs/erofs/data.c | 429 ++++++++ fs/erofs/decompressor.c | 359 +++++++ fs/erofs/dir.c | 147 +++ fs/erofs/erofs_fs.h | 316 ++++++ fs/erofs/inode.c | 326 +++++++ fs/erofs/internal.h | 552 +++++++++++ fs/erofs/namei.c | 251 +++++ fs/erofs/super.c | 666 +++++++++++++ fs/erofs/tagptr.h | 110 +++ fs/erofs/utils.c | 335 +++++++ fs/erofs/xattr.c | 700 +++++++++++++ fs/erofs/xattr.h | 94 ++ fs/erofs/zdata.c | 1408 +++++++++++++++++++++++++++ fs/erofs/zdata.h | 195 ++++ fs/erofs/zmap.c | 462 +++++++++ fs/erofs/zpvec.h | 159 +++ include/trace/events/erofs.h | 256 +++++ include/uapi/linux/magic.h | 1 + 24 files changed, 7160 insertions(+) create mode 100644 Documentation/filesystems/erofs.txt create mode 100644 fs/erofs/Kconfig create mode 100644 fs/erofs/Makefile create mode 100644 fs/erofs/compress.h create mode 100644 fs/erofs/data.c create mode 100644 fs/erofs/decompressor.c create mode 100644 fs/erofs/dir.c create mode 100644 fs/erofs/erofs_fs.h create mode 100644 fs/erofs/inode.c create mode 100644 fs/erofs/internal.h create mode 100644 fs/erofs/namei.c create mode 100644 fs/erofs/super.c create mode 100644 fs/erofs/tagptr.h create mode 100644 fs/erofs/utils.c create mode 100644 fs/erofs/xattr.c create mode 100644 fs/erofs/xattr.h create mode 100644 fs/erofs/zdata.c create mode 100644 fs/erofs/zdata.h create mode 100644 fs/erofs/zmap.c create mode 100644 fs/erofs/zpvec.h create mode 100644 include/trace/events/erofs.h -- 2.17.1 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel