Re: [PATCH v5] f2fs: compress: support compress level

From: Jaegeuk Kim
Date: Thu Dec 03 2020 - 00:48:06 EST

On 12/03, Chao Yu wrote:
> Expand 'compress_algorithm' mount option to accept parameter as format of
> <algorithm>:<level>, by this way, it gives a way to allow user to do more
> specified config on lz4 and zstd compression level, then f2fs compression
> can provide higher compress ratio.
>
> In order to set compress level for lz4 algorithm, it needs to set
> CONFIG_LZ4HC_COMPRESS and CONFIG_F2FS_FS_LZ4HC config to enable lz4hc
> compress algorithm.
>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> v5:
> - avoid compile error if CONFIG_F2FS_FS_ZSTD is off.
> Documentation/filesystems/f2fs.rst | 5 +++
> fs/f2fs/Kconfig | 9 ++++
> fs/f2fs/compress.c | 40 +++++++++++++++--
> fs/f2fs/f2fs.h | 9 ++++
> fs/f2fs/super.c | 72 +++++++++++++++++++++++++++++-
> include/linux/f2fs_fs.h | 3 ++
> 6 files changed, 133 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> index fd413d319e93..eef683c3266f 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -249,6 +249,11 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off checkpointing. Set to "enabl
> This space is reclaimed once checkpoint=enable.
> compress_algorithm=%s Control compress algorithm, currently f2fs supports "lzo",
> "lz4", "zstd" and "lzo-rle" algorithm.
> +compress_algorithm=%s:%d Control compress algorithm and its compress level, now, only
> + "lz4" and "zstd" support compress level config.
> + level range

This gives a warning like below.

Applying: f2fs: compress: support compress level
.git/rebase-apply/patch:22: space before tab in indent.
level range
warning: 1 line adds whitespace errors.


> + lz4 3 - 16
> + zstd 1 - 22
> 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 d13c5c6a9787..8134b145ae4f 100644
> --- a/fs/f2fs/Kconfig
> +++ b/fs/f2fs/Kconfig
> @@ -119,6 +119,15 @@ config F2FS_FS_LZ4
> help
> Support LZ4 compress algorithm, if unsure, say Y.
>
> +config F2FS_FS_LZ4HC
> + bool "LZ4HC compression support"
> + depends on F2FS_FS_COMPRESSION
> + depends on F2FS_FS_LZ4
> + select LZ4HC_COMPRESS
> + default y
> + help
> + Support LZ4HC compress algorithm, if unsure, say Y.
> +
> config F2FS_FS_ZSTD
> bool "ZSTD compression support"
> depends on F2FS_FS_COMPRESSION
> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> index db82da311fe4..dfadbc78946c 100644
> --- a/fs/f2fs/compress.c
> +++ b/fs/f2fs/compress.c
> @@ -254,8 +254,13 @@ static const struct f2fs_compress_ops f2fs_lzo_ops = {
> #ifdef CONFIG_F2FS_FS_LZ4
> static int lz4_init_compress_ctx(struct compress_ctx *cc)
> {
> - cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
> - LZ4_MEM_COMPRESS, GFP_NOFS);
> + unsigned int size;
> + unsigned char level = F2FS_I(cc->inode)->i_compress_flag >>
> + COMPRESS_LEVEL_OFFSET;
> +
> + size = level ? LZ4HC_MEM_COMPRESS : LZ4_MEM_COMPRESS;
> +
> + cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode), size, GFP_NOFS);
> if (!cc->private)
> return -ENOMEM;
>
> @@ -274,10 +279,34 @@ static void lz4_destroy_compress_ctx(struct compress_ctx *cc)
> cc->private = NULL;
> }
>
> +#ifdef CONFIG_F2FS_FS_LZ4HC
> +static int lz4hc_compress_pages(struct compress_ctx *cc)
> +{
> + unsigned char level = F2FS_I(cc->inode)->i_compress_flag >>
> + COMPRESS_LEVEL_OFFSET;
> + int len;
> +
> + if (level)
> + len = LZ4_compress_HC(cc->rbuf, cc->cbuf->cdata, cc->rlen,
> + cc->clen, level, cc->private);
> + else
> + len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen,
> + cc->clen, cc->private);
> + if (!len)
> + return -EAGAIN;
> +
> + cc->clen = len;
> + return 0;
> +}
> +#endif
> +
> static int lz4_compress_pages(struct compress_ctx *cc)
> {
> int len;
>
> +#ifdef CONFIG_F2FS_FS_LZ4HC
> + return lz4hc_compress_pages(cc);
> +#endif
> len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen,
> cc->clen, cc->private);
> if (!len)
> @@ -327,8 +356,13 @@ static int zstd_init_compress_ctx(struct compress_ctx *cc)
> ZSTD_CStream *stream;
> void *workspace;
> unsigned int workspace_size;
> + unsigned char level = F2FS_I(cc->inode)->i_compress_flag >>
> + COMPRESS_LEVEL_OFFSET;
> +
> + if (!level)
> + level = F2FS_ZSTD_DEFAULT_CLEVEL;
>
> - params = ZSTD_getParams(F2FS_ZSTD_DEFAULT_CLEVEL, cc->rlen, 0);
> + params = ZSTD_getParams(level, cc->rlen, 0);
> workspace_size = ZSTD_CStreamWorkspaceBound(params.cParams);
>
> workspace = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 377a2e2bf466..76edec7483f3 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -147,6 +147,7 @@ struct f2fs_mount_info {
> /* For compression */
> unsigned char compress_algorithm; /* algorithm type */
> unsigned char compress_log_size; /* cluster log size */
> + unsigned char compress_level; /* compress level */
> bool compress_chksum; /* compressed data chksum */
> unsigned char compress_ext_cnt; /* extension count */
> int compress_mode; /* compression mode */
> @@ -736,6 +737,7 @@ struct f2fs_inode_info {
> atomic_t i_compr_blocks; /* # of compressed blocks */
> unsigned char i_compress_algorithm; /* algorithm type */
> unsigned char i_log_cluster_size; /* log of cluster size */
> + unsigned char i_compress_level; /* compress level (lz4hc,zstd) */
> unsigned short i_compress_flag; /* compress flag */
> unsigned int i_cluster_size; /* cluster size */
> };
> @@ -1308,6 +1310,8 @@ struct compress_data {
>
> #define F2FS_COMPRESSED_PAGE_MAGIC 0xF5F2C000
>
> +#define COMPRESS_LEVEL_OFFSET 8
> +
> /* compress context */
> struct compress_ctx {
> struct inode *inode; /* inode the context belong to */
> @@ -3959,6 +3963,11 @@ static inline void set_compress_context(struct inode *inode)
> 1 << COMPRESS_CHKSUM : 0;
> F2FS_I(inode)->i_cluster_size =
> 1 << F2FS_I(inode)->i_log_cluster_size;
> + if (F2FS_I(inode)->i_compress_algorithm == COMPRESS_LZ4 &&
> + F2FS_OPTION(sbi).compress_level)
> + F2FS_I(inode)->i_compress_flag |=
> + F2FS_OPTION(sbi).compress_level <<
> + COMPRESS_LEVEL_OFFSET;
> F2FS_I(inode)->i_flags |= F2FS_COMPR_FL;
> set_inode_flag(inode, FI_COMPRESSED_FILE);
> stat_inc_compr_inode(inode);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 8442333ca0e2..44ba870bb352 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -25,6 +25,8 @@
> #include <linux/quota.h>
> #include <linux/unicode.h>
> #include <linux/part_stat.h>
> +#include <linux/zstd.h>
> +#include <linux/lz4.h>
>
> #include "f2fs.h"
> #include "node.h"
> @@ -466,6 +468,57 @@ static int f2fs_set_test_dummy_encryption(struct super_block *sb,
> return 0;
> }
>
> +#ifdef CONFIG_F2FS_FS_COMPRESSION
> +static int f2fs_compress_set_level(struct f2fs_sb_info *sbi, const char *str,
> + int type)
> +{
> + unsigned int level;
> + int len;
> +
> + if (type == COMPRESS_LZ4)
> + len = 3;
> + else if (type == COMPRESS_ZSTD)
> + len = 4;
> + else
> + return 0;
> +
> + if (strlen(str) == len)
> + return 0;
> +
> + str += len;
> +
> + if (str[0] != ':') {
> + f2fs_info(sbi, "wrong format, e.g. <alg_name>:<compr_level>");
> + return -EINVAL;
> + }
> + if (kstrtouint(str + 1, 10, &level))
> + return -EINVAL;
> + if (type == COMPRESS_LZ4) {
> +#ifdef CONFIG_F2FS_FS_LZ4HC
> + if (level < LZ4HC_MIN_CLEVEL || level > LZ4HC_MAX_CLEVEL) {
> + f2fs_info(sbi, "invalid lz4hc compress level: %d", level);
> + return -EINVAL;
> + }
> +#else
> + f2fs_info(sbi, "doesn't support lz4hc compression");
> + return 0;
> +#endif
> + } else if (type == COMPRESS_ZSTD) {
> +#ifdef CONFIG_F2FS_FS_ZSTD
> + if (!level || level > ZSTD_maxCLevel()) {
> + f2fs_info(sbi, "invalid zstd compress level: %d", level);
> + return -EINVAL;
> + }
> +#else
> + f2fs_info(sbi, "doesn't support zstd compression");
> + return 0;
> +#endif
> + }
> + F2FS_OPTION(sbi).compress_level = level;
> + return 0;
> +}
> +#endif
> +
> static int parse_options(struct super_block *sb, char *options, bool is_remount)
> {
> struct f2fs_sb_info *sbi = F2FS_SB(sb);
> @@ -886,10 +939,22 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> if (!strcmp(name, "lzo")) {
> F2FS_OPTION(sbi).compress_algorithm =
> COMPRESS_LZO;
> - } else if (!strcmp(name, "lz4")) {
> + } else if (!strncmp(name, "lz4", 3)) {
> + ret = f2fs_compress_set_level(sbi, name,
> + COMPRESS_LZ4);
> + if (ret) {
> + kfree(name);
> + return -EINVAL;
> + }
> F2FS_OPTION(sbi).compress_algorithm =
> COMPRESS_LZ4;
> - } else if (!strcmp(name, "zstd")) {
> + } else if (!strncmp(name, "zstd", 4)) {
> + ret = f2fs_compress_set_level(sbi, name,
> + COMPRESS_ZSTD);
> + if (ret) {
> + kfree(name);
> + return -EINVAL;
> + }
> F2FS_OPTION(sbi).compress_algorithm =
> COMPRESS_ZSTD;
> } else if (!strcmp(name, "lzo-rle")) {
> @@ -1547,6 +1612,9 @@ static inline void f2fs_show_compress_options(struct seq_file *seq,
> }
> seq_printf(seq, ",compress_algorithm=%s", algtype);
>
> + if (!F2FS_OPTION(sbi).compress_level)
> + seq_printf(seq, ":%d", F2FS_OPTION(sbi).compress_level);
> +
> seq_printf(seq, ",compress_log_size=%u",
> F2FS_OPTION(sbi).compress_log_size);
>
> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
> index 55be7afeee90..2dcc63fe8494 100644
> --- a/include/linux/f2fs_fs.h
> +++ b/include/linux/f2fs_fs.h
> @@ -275,6 +275,9 @@ struct f2fs_inode {
> __u8 i_compress_algorithm; /* compress algorithm */
> __u8 i_log_cluster_size; /* log of cluster size */
> __le16 i_compress_flag; /* compress flag */
> + /* 0 bit: chksum flag
> + * [10,15] bits: compress level
> + */
> __le32 i_extra_end[0]; /* for attribute size calculation */
> } __packed;
> __le32 i_addr[DEF_ADDRS_PER_INODE]; /* Pointers to data blocks */
> --
> 2.26.2