Commit 8f2fb72f authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: update compression algorithm status 



The following changes are proposed in the upcoming Linux 7.0:

 - Enable LZMA support by default, as it's already in use by Fedora 42/43
   and some Android vendors for minimal filesystem sizes;

 - Promote DEFLATE and Zstandard out of EXPERIMENTAL status, given that
   they have been landed and well-tested for over a year and are
   already ready for general use.

Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent c134a40f

Documentation/filesystems/erofs.rst

+3 −3
Original line number Diff line number Diff line
@@ -63,9 +63,9 @@ Here are the main features of EROFS: 
 - Support POSIX.1e ACLs by using extended attributes;



 - Support transparent data compression as an option:

   LZ4, MicroLZMA and DEFLATE algorithms can be used on a per-file basis; In

   addition, inplace decompression is also supported to avoid bounce compressed

   buffers and unnecessary page cache thrashing.

   LZ4, MicroLZMA, DEFLATE and Zstandard algorithms can be used on a per-file

   basis; In addition, inplace decompression is also supported to avoid bounce

   compressed buffers and unnecessary page cache thrashing.



 - Support chunk-based data deduplication and rolling-hash compressed data

   deduplication;

fs/erofs/Kconfig

+3 −8
Original line number Diff line number Diff line
@@ -112,13 +112,14 @@ config EROFS_FS_ZIP 
config EROFS_FS_ZIP_LZMA

	bool "EROFS LZMA compressed data support"

	depends on EROFS_FS_ZIP

	default y

	help

	  Saying Y here includes support for reading EROFS file systems

	  containing LZMA compressed data, specifically called microLZMA. It

	  gives better compression ratios than the default LZ4 format, at the

	  expense of more CPU overhead.



	  If unsure, say N.

	  Say N if you want to disable LZMA compression support.



config EROFS_FS_ZIP_DEFLATE

	bool "EROFS DEFLATE compressed data support"
@@ -129,9 +130,6 @@ config EROFS_FS_ZIP_DEFLATE 
	  ratios than the default LZ4 format, while it costs more CPU

	  overhead.



	  DEFLATE support is an experimental feature for now and so most

	  file systems will be readable without selecting this option.



	  If unsure, say N.



config EROFS_FS_ZIP_ZSTD
@@ -141,10 +139,7 @@ config EROFS_FS_ZIP_ZSTD 
	  Saying Y here includes support for reading EROFS file systems

	  containing Zstandard compressed data.  It gives better compression

	  ratios than the default LZ4 format, while it costs more CPU

	  overhead.



	  Zstandard support is an experimental feature for now and so most

	  file systems will be readable without selecting this option.

	  overhead and memory footprint.



	  If unsure, say N.

fs/erofs/decompressor_deflate.c

+0 −1
Original line number Diff line number Diff line
@@ -89,7 +89,6 @@ static int z_erofs_load_deflate_config(struct super_block *sb, 
		inited = true;

	}

	mutex_unlock(&deflate_resize_mutex);

	erofs_info(sb, "EXPERIMENTAL DEFLATE feature in use. Use at your own risk!");

	return 0;

failed:

	mutex_unlock(&deflate_resize_mutex);