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| author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-10-11 05:31:45 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2021-10-19 23:44:30 +0800 |
| commit | 622ceaddb7649ca328832f50ba1400af778d75fa (patch) | |
| tree | 6e6a3db1cff711620944b9e283c2bd5f4dbd6171 /fs/erofs/internal.h | |
| parent | 966edfb0a3dc2adf5aab461c298fa0feb02f49d6 (diff) | |
| download | lwn-622ceaddb7649ca328832f50ba1400af778d75fa.tar.gz lwn-622ceaddb7649ca328832f50ba1400af778d75fa.zip | |
erofs: lzma compression support
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>
Diffstat (limited to 'fs/erofs/internal.h')
| -rw-r--r-- | fs/erofs/internal.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 354ce3cb2b32..a6a53d22dfd6 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -407,6 +407,8 @@ struct erofs_map_blocks { * approach instead if possible since it's more metadata lightweight.) */ #define EROFS_GET_BLOCKS_FIEMAP 0x0002 +/* Used to map the whole extent if non-negligible data is requested for LZMA */ +#define EROFS_GET_BLOCKS_READMORE 0x0004 enum { Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX, @@ -537,6 +539,26 @@ static inline int z_erofs_load_lz4_config(struct super_block *sb, } #endif /* !CONFIG_EROFS_FS_ZIP */ +#ifdef CONFIG_EROFS_FS_ZIP_LZMA +int z_erofs_lzma_init(void); +void z_erofs_lzma_exit(void); +int z_erofs_load_lzma_config(struct super_block *sb, + struct erofs_super_block *dsb, + struct z_erofs_lzma_cfgs *lzma, int size); +#else +static inline int z_erofs_lzma_init(void) { return 0; } +static inline int z_erofs_lzma_exit(void) { return 0; } +static inline int z_erofs_load_lzma_config(struct super_block *sb, + struct erofs_super_block *dsb, + struct z_erofs_lzma_cfgs *lzma, int size) { + if (lzma) { + erofs_err(sb, "lzma algorithm isn't enabled"); + return -EINVAL; + } + return 0; +} +#endif /* !CONFIG_EROFS_FS_ZIP */ + #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ #endif /* __EROFS_INTERNAL_H */ |