The patch titled
Subject: zram: add lz4 compression backend support
has been added to the -mm mm-unstable branch. Its filename is
zram-add-lz4-compression-backend-support.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-add-lz4-compression-backend-support.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Subject: zram: add lz4 compression backend support
Date: Wed, 15 May 2024 16:12:40 +0900
Add s/w lz4 compression support.
Link: https://lkml.kernel.org/r/20240515071645.1788128-4-senozhatsky@xxxxxxxxxxxx
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Nick Terrell <terrelln@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/Kconfig | 11 ++++
drivers/block/zram/Makefile | 1
drivers/block/zram/backend_lz4.c | 73 +++++++++++++++++++++++++++++
drivers/block/zram/backend_lz4.h | 10 +++
drivers/block/zram/zcomp.c | 4 +
5 files changed, 99 insertions(+)
--- /dev/null
+++ a/drivers/block/zram/backend_lz4.c
@@ -0,0 +1,73 @@
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "backend_lz4.h"
+
+struct lz4_ctx {
+ void *mem;
+ s32 level;
+};
+
+static void lz4_destroy(void *ctx)
+{
+ struct lz4_ctx *zctx = ctx;
+
+ vfree(zctx->mem);
+ kfree(zctx);
+}
+
+static void *lz4_create(void)
+{
+ struct lz4_ctx *ctx;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ /* @FIXME: using a hardcoded LZ4_ACCELERATION_DEFAULT for now */
+ ctx->level = LZ4_ACCELERATION_DEFAULT;
+ ctx->mem = vmalloc(LZ4_MEM_COMPRESS);
+ if (!ctx->mem)
+ goto error;
+
+ return ctx;
+error:
+ lz4_destroy(ctx);
+ return NULL;
+}
+
+static int lz4_compress(void *ctx, const unsigned char *src,
+ unsigned char *dst, size_t *dst_len)
+{
+ struct lz4_ctx *zctx = ctx;
+ int ret;
+
+ ret = LZ4_compress_fast(src, dst, PAGE_SIZE, *dst_len,
+ zctx->level, zctx->mem);
+ if (!ret)
+ return -EINVAL;
+ *dst_len = ret;
+ return 0;
+}
+
+static int lz4_decompress(void *ctx, const unsigned char *src,
+ size_t src_len, unsigned char *dst)
+{
+ int dst_len = PAGE_SIZE;
+ int ret;
+
+ ret = LZ4_decompress_safe(src, dst, src_len, dst_len);
+ if (ret < 0)
+ return -EINVAL;
+ return 0;
+}
+
+struct zcomp_backend backend_lz4 = {
+ .compress = lz4_compress,
+ .decompress = lz4_decompress,
+ .create_ctx = lz4_create,
+ .destroy_ctx = lz4_destroy,
+ .name = "lz4",
+};
--- /dev/null
+++ a/drivers/block/zram/backend_lz4.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_LZ4_H__
+#define __BACKEND_LZ4_H__
+
+#include "zcomp.h"
+
+extern struct zcomp_backend backend_lz4;
+
+#endif /* __BACKEND_LZ4_H__ */
--- a/drivers/block/zram/Kconfig~zram-add-lz4-compression-backend-support
+++ a/drivers/block/zram/Kconfig
@@ -20,6 +20,12 @@ config ZRAM_BACKEND_LZO
select LZO_COMPRESS
select LZO_DECOMPRESS
+config ZRAM_BACKEND_LZ4
+ bool "lz4 compression support"
+ depends on ZRAM
+ select LZ4_COMPRESS
+ select LZ4_DECOMPRESS
+
choice
prompt "Default zram compressor"
default ZRAM_DEF_COMP_LZORLE
@@ -33,12 +39,17 @@ config ZRAM_DEF_COMP_LZO
bool "lzo"
depends on ZRAM_BACKEND_LZO
+config ZRAM_DEF_COMP_LZ4
+ bool "lz4"
+ depends on ZRAM_BACKEND_LZ4
+
endchoice
config ZRAM_DEF_COMP
string
default "lzo-rle" if ZRAM_DEF_COMP_LZORLE
default "lzo" if ZRAM_DEF_COMP_LZO
+ default "lz4" if ZRAM_DEF_COMP_LZ4
default "unset-value"
config ZRAM_WRITEBACK
--- a/drivers/block/zram/Makefile~zram-add-lz4-compression-backend-support
+++ a/drivers/block/zram/Makefile
@@ -3,5 +3,6 @@
zram-y := zcomp.o zram_drv.o
zram-$(CONFIG_ZRAM_BACKEND_LZO) += backend_lzorle.o backend_lzo.o
+zram-$(CONFIG_ZRAM_BACKEND_LZ4) += backend_lz4.o
obj-$(CONFIG_ZRAM) += zram.o
--- a/drivers/block/zram/zcomp.c~zram-add-lz4-compression-backend-support
+++ a/drivers/block/zram/zcomp.c
@@ -17,12 +17,16 @@
#include "backend_lzo.h"
#include "backend_lzorle.h"
+#include "backend_lz4.h"
static struct zcomp_backend *backends[] = {
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
&backend_lzorle,
&backend_lzo,
#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4)
+ &backend_lz4,
+#endif
NULL
};
_
Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are
zram-move-from-crypto-api-to-custom-comp-backends-api.patch
zram-add-lzo-and-lzorle-compression-backends-support.patch
zram-add-lz4-compression-backend-support.patch
zram-add-lz4hc-compression-backend-support.patch
zram-add-zstd-compression-backend-support.patch
zram-pass-estimated-src-size-hint-to-zstd.patch
zram-add-zlib-compression-backend-support.patch
zram-add-842-compression-backend-support.patch
zram-check-that-backends-array-has-at-least-one-backend.patch
zram-introduce-zcomp_config-structure.patch
zram-extend-comp_algorithm-attr-write-handling.patch
zram-support-compression-level-comp-config.patch
zram-add-support-for-dict-comp-config.patch
lib-zstd-export-api-needed-for-dictionary-support.patch
zram-add-dictionary-support-to-zstd-backend.patch
zram-add-config-init-release-backend-callbacks.patch
zram-share-dictionaries-between-per-cpu-contexts.patch
zram-add-dictionary-support-to-lz4.patch
lib-lz4hc-export-lz4_resetstreamhc-symbol.patch
zram-add-dictionary-support-to-lz4hc.patch
documentation-zram-add-documentation-for-algorithm-parameters.patch
