Messages in this thread | | | Subject | Re: [PATCH] f2fs: compress: support zstd compress algorithm | From | Chao Yu <> | Date | Tue, 3 Mar 2020 09:50:52 +0800 |
| |
On 2020/3/3 1:50, Eric Biggers wrote: > On Fri, Feb 28, 2020 at 07:14:56PM +0800, Chao Yu wrote: >> Add zstd compress algorithm support, use "compress_algorithm=zstd" >> mountoption to enable it. >> >> Signed-off-by: Chao Yu <yuchao0@huawei.com> >> --- >> Documentation/filesystems/f2fs.txt | 4 +- >> fs/f2fs/Kconfig | 9 ++ >> fs/f2fs/compress.c | 151 +++++++++++++++++++++++++++++ >> fs/f2fs/f2fs.h | 2 + >> fs/f2fs/super.c | 7 ++ >> include/trace/events/f2fs.h | 3 +- >> 6 files changed, 173 insertions(+), 3 deletions(-) >> >> diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt >> index 4eb3e2ddd00e..b1a66cf0e967 100644 >> --- a/Documentation/filesystems/f2fs.txt >> +++ b/Documentation/filesystems/f2fs.txt >> @@ -235,8 +235,8 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off checkpointing. Set to "en >> hide up to all remaining free space. The actual space that >> would be unusable can be viewed at /sys/fs/f2fs/<disk>/unusable >> This space is reclaimed once checkpoint=enable. >> -compress_algorithm=%s Control compress algorithm, currently f2fs supports "lzo" >> - and "lz4" algorithm. >> +compress_algorithm=%s Control compress algorithm, currently f2fs supports "lzo", >> + "lz4" and "zstd" algorithm. >> compress_log_size=%u Support configuring compress cluster size, the size will >> be 4KB * (1 << %u), 16KB is minimum size, also it's >> default size. >> diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig >> index f0faada30f30..bb68d21e1f8c 100644 >> --- a/fs/f2fs/Kconfig >> +++ b/fs/f2fs/Kconfig >> @@ -118,3 +118,12 @@ config F2FS_FS_LZ4 >> default y >> help >> Support LZ4 compress algorithm, if unsure, say Y. >> + >> +config F2FS_FS_ZSTD >> + bool "ZSTD compression support" >> + depends on F2FS_FS_COMPRESSION >> + select ZSTD_COMPRESS >> + select ZSTD_DECOMPRESS >> + default y >> + help >> + Support ZSTD compress algorithm, if unsure, say Y. >> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c >> index bd3ea01db448..c8e1175eaf4e 100644 >> --- a/fs/f2fs/compress.c >> +++ b/fs/f2fs/compress.c >> @@ -11,6 +11,7 @@ >> #include <linux/backing-dev.h> >> #include <linux/lzo.h> >> #include <linux/lz4.h> >> +#include <linux/zstd.h> >> >> #include "f2fs.h" >> #include "node.h" >> @@ -291,6 +292,151 @@ static const struct f2fs_compress_ops f2fs_lz4_ops = { >> }; >> #endif >> >> +#ifdef CONFIG_F2FS_FS_ZSTD >> +#define F2FS_ZSTD_DEFAULT_CLEVEL 1 >> + >> +static int zstd_init_compress_ctx(struct compress_ctx *cc) >> +{ >> + return 0; >> +} >> + >> +static void zstd_destroy_compress_ctx(struct compress_ctx *cc) >> +{ >> +} >> + >> +static int zstd_compress_pages(struct compress_ctx *cc) >> +{ >> + ZSTD_parameters params; >> + ZSTD_CStream *stream; >> + ZSTD_inBuffer inbuf; >> + ZSTD_outBuffer outbuf; >> + void *workspace; >> + unsigned int workspace_size; >> + int src_size = cc->rlen; >> + int dst_size = src_size - PAGE_SIZE - COMPRESS_HEADER_SIZE; >> + int ret; >> + >> + params = ZSTD_getParams(F2FS_ZSTD_DEFAULT_CLEVEL, src_size, 0); >> + workspace_size = ZSTD_CStreamWorkspaceBound(params.cParams); >> + >> + workspace = f2fs_kvmalloc(F2FS_I_SB(cc->inode), >> + workspace_size, GFP_NOFS); >> + if (!workspace) >> + return -ENOMEM; >> + >> + stream = ZSTD_initCStream(params, 0, >> + workspace, workspace_size); > > Why is this allocating the memory for every compression operation, instead of > ahead of time in ->init_compress_ctx()?
Actually, zstd decompression flow needs workspace like its compression flow, however I realized that we don't have related callback interfaces in decompress path, so I just add all steps of {,de}compression into .{,de}compress_pages() functions.
In order to not break callback function fwk of compression, how about adding {init,destroy}_decompress_ctx() callback interfaces, and relocating initialization and destroy step into correct callback functions?
Thanks,
> > - Eric > . >
| |