f2fs: compress: support compress level

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.

CR and performance number on lz4/lz4hc algorithm:

dd if=enwik9 of=compressed_file conv=fsync

Original blocks:	244382

			lz4			lz4hc-9
compressed blocks	170647			163270
compress ratio		69.8%			66.8%
speed			16.4207 s, 60.9 MB/s	26.7299 s, 37.4 MB/s

compress ratio = after / before

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 87 insertions, 2 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index a275bd312ae5..c8be27a9eed6 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"
@@ -464,6 +466,74 @@ static int f2fs_set_test_dummy_encryption(struct super_block *sb,
 	return 0;
 }
 
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+#ifdef CONFIG_F2FS_FS_LZ4
+static int f2fs_set_lz4hc_level(struct f2fs_sb_info *sbi, const char *str)
+{
+#ifdef CONFIG_F2FS_FS_LZ4HC
+	unsigned int level;
+#endif
+
+	if (strlen(str) == 3) {
+		F2FS_OPTION(sbi).compress_level = 0;
+		return 0;
+	}
+
+#ifdef CONFIG_F2FS_FS_LZ4HC
+	str += 3;
+
+	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 (level < LZ4HC_MIN_CLEVEL || level > LZ4HC_MAX_CLEVEL) {
+		f2fs_info(sbi, "invalid lz4hc compress level: %d", level);
+		return -EINVAL;
+	}
+
+	F2FS_OPTION(sbi).compress_level = level;
+	return 0;
+#else
+	f2fs_info(sbi, "kernel doesn't support lz4hc compression");
+	return -EINVAL;
+#endif
+}
+#endif
+
+#ifdef CONFIG_F2FS_FS_ZSTD
+static int f2fs_set_zstd_level(struct f2fs_sb_info *sbi, const char *str)
+{
+	unsigned int level;
+	int len = 4;
+
+	if (strlen(str) == len) {
+		F2FS_OPTION(sbi).compress_level = 0;
+		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 (!level || level > ZSTD_maxCLevel()) {
+		f2fs_info(sbi, "invalid zstd compress level: %d", level);
+		return -EINVAL;
+	}
+
+	F2FS_OPTION(sbi).compress_level = level;
+	return 0;
+}
+#endif
+#endif
+
 static int parse_options(struct super_block *sb, char *options, bool is_remount)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
@@ -883,20 +953,31 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 				return -ENOMEM;
 			if (!strcmp(name, "lzo")) {
 #ifdef CONFIG_F2FS_FS_LZO
+				F2FS_OPTION(sbi).compress_level = 0;
 				F2FS_OPTION(sbi).compress_algorithm =
 								COMPRESS_LZO;
 #else
 				f2fs_info(sbi, "kernel doesn't support lzo compression");
 #endif
-			} else if (!strcmp(name, "lz4")) {
+			} else if (!strncmp(name, "lz4", 3)) {
 #ifdef CONFIG_F2FS_FS_LZ4
+				ret = f2fs_set_lz4hc_level(sbi, name);
+				if (ret) {
+					kfree(name);
+					return -EINVAL;
+				}
 				F2FS_OPTION(sbi).compress_algorithm =
 								COMPRESS_LZ4;
 #else
 				f2fs_info(sbi, "kernel doesn't support lz4 compression");
 #endif
-			} else if (!strcmp(name, "zstd")) {
+			} else if (!strncmp(name, "zstd", 4)) {
 #ifdef CONFIG_F2FS_FS_ZSTD
+				ret = f2fs_set_zstd_level(sbi, name);
+				if (ret) {
+					kfree(name);
+					return -EINVAL;
+				}
 				F2FS_OPTION(sbi).compress_algorithm =
 								COMPRESS_ZSTD;
 #else
@@ -904,6 +985,7 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 #endif
 			} else if (!strcmp(name, "lzo-rle")) {
 #ifdef CONFIG_F2FS_FS_LZORLE
+				F2FS_OPTION(sbi).compress_level = 0;
 				F2FS_OPTION(sbi).compress_algorithm =
 								COMPRESS_LZORLE;
 #else
@@ -1555,6 +1637,9 @@ 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);