From 504e74941c5dbca8aaa46adef0dcf0db0227cda1 Mon Sep 17 00:00:00 2001
From: Chao Yu <yuchao0@huawei.com>
Date: Wed, 8 Apr 2020 19:56:32 +0800
Subject: [PATCH] f2fs: compress: support lzo-rle compress algorithm

LZO-RLE extension (run length encoding) was introduced to improve
performance of LZO algorithm in scenario of data contains many zeros,
zram has changed to use this extended algorithm by default, this
patch adds to support this algorithm extension, to enable this
extension, it needs to enable F2FS_FS_LZO and F2FS_FS_LZORLE config,
and specifies "compress_algorithm=lzo-rle" mountoption.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/Kconfig             | 10 ++++++++++
 fs/f2fs/compress.c          | 30 ++++++++++++++++++++++++++++++
 fs/f2fs/f2fs.h              |  1 +
 fs/f2fs/super.c             |  6 ++++++
 include/trace/events/f2fs.h |  3 ++-
 5 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
index bb68d21e1f8c..d13c5c6a9787 100644
--- a/fs/f2fs/Kconfig
+++ b/fs/f2fs/Kconfig
@@ -127,3 +127,13 @@ config F2FS_FS_ZSTD
 	default y
 	help
 	  Support ZSTD compress algorithm, if unsure, say Y.
+
+config F2FS_FS_LZORLE
+	bool "LZO-RLE compression support"
+	depends on F2FS_FS_COMPRESSION
+	depends on F2FS_FS_LZO
+	select LZO_COMPRESS
+	select LZO_DECOMPRESS
+	default y
+	help
+	  Support LZO-RLE compress algorithm, if unsure, say Y.
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index b726aad898de..85b969c8b32f 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -443,6 +443,31 @@ static const struct f2fs_compress_ops f2fs_zstd_ops = {
 };
 #endif
 
+#ifdef CONFIG_F2FS_FS_LZO
+#ifdef CONFIG_F2FS_FS_LZORLE
+static int lzorle_compress_pages(struct compress_ctx *cc)
+{
+	int ret;
+
+	ret = lzorle1x_1_compress(cc->rbuf, cc->rlen, cc->cbuf->cdata,
+					&cc->clen, cc->private);
+	if (ret != LZO_E_OK) {
+		printk_ratelimited("%sF2FS-fs (%s): lzo-rle compress failed, ret:%d\n",
+				KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, ret);
+		return -EIO;
+	}
+	return 0;
+}
+
+static const struct f2fs_compress_ops f2fs_lzorle_ops = {
+	.init_compress_ctx	= lzo_init_compress_ctx,
+	.destroy_compress_ctx	= lzo_destroy_compress_ctx,
+	.compress_pages		= lzorle_compress_pages,
+	.decompress_pages	= lzo_decompress_pages,
+};
+#endif
+#endif
+
 static const struct f2fs_compress_ops *f2fs_cops[COMPRESS_MAX] = {
 #ifdef CONFIG_F2FS_FS_LZO
 	&f2fs_lzo_ops,
@@ -459,6 +484,11 @@ static const struct f2fs_compress_ops *f2fs_cops[COMPRESS_MAX] = {
 #else
 	NULL,
 #endif
+#if defined(CONFIG_F2FS_FS_LZO) && defined(CONFIG_F2FS_FS_LZORLE)
+	&f2fs_lzorle_ops,
+#else
+	NULL,
+#endif
 };
 
 bool f2fs_is_compress_backend_ready(struct inode *inode)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index b58008788273..41fd1e0bb390 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1317,6 +1317,7 @@ enum compress_algorithm_type {
 	COMPRESS_LZO,
 	COMPRESS_LZ4,
 	COMPRESS_ZSTD,
+	COMPRESS_LZORLE,
 	COMPRESS_MAX,
 };
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index e80aef941cba..ebf2bd19fd8e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -832,6 +832,9 @@ static int parse_options(struct super_block *sb, char *options)
 			} else if (!strcmp(name, "zstd")) {
 				F2FS_OPTION(sbi).compress_algorithm =
 								COMPRESS_ZSTD;
+			} else if (!strcmp(name, "lzo-rle")) {
+				F2FS_OPTION(sbi).compress_algorithm =
+								COMPRESS_LZORLE;
 			} else {
 				kfree(name);
 				return -EINVAL;
@@ -1425,6 +1428,9 @@ static inline void f2fs_show_compress_options(struct seq_file *seq,
 	case COMPRESS_ZSTD:
 		algtype = "zstd";
 		break;
+	case COMPRESS_LZORLE:
+		algtype = "lzo-rle";
+		break;
 	}
 	seq_printf(seq, ",compress_algorithm=%s", algtype);
 
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 542b02544162..c0216671e076 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -154,7 +154,8 @@ TRACE_DEFINE_ENUM(CP_PAUSE);
 	__print_symbolic(type,						\
 		{ COMPRESS_LZO,		"LZO" },			\
 		{ COMPRESS_LZ4,		"LZ4" },			\
-		{ COMPRESS_ZSTD,	"ZSTD" })
+		{ COMPRESS_ZSTD,	"ZSTD" },			\
+		{ COMPRESS_LZORLE,	"LZO-RLE" })
 
 struct f2fs_sb_info;
 struct f2fs_io_info;