The patch titled
Subject: zram: add zstd compression backend support
has been added to the -mm mm-unstable branch. Its filename is
zram-add-zstd-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-zstd-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 zstd compression backend support
Date: Fri, 12 Jul 2024 14:18:19 +0900
Add s/w zstd compression.
Link: https://lkml.kernel.org/r/20240712051850.484318-9-senozhatsky@xxxxxxxxxxxx
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Nick Terrell <terrelln@xxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/Kconfig | 11 +++
drivers/block/zram/Makefile | 1
drivers/block/zram/backend_zstd.c | 97 ++++++++++++++++++++++++++++
drivers/block/zram/backend_zstd.h | 10 ++
drivers/block/zram/zcomp.c | 4 +
5 files changed, 123 insertions(+)
--- /dev/null
+++ a/drivers/block/zram/backend_zstd.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/zstd.h>
+
+#include "backend_zstd.h"
+
+struct zstd_ctx {
+ zstd_cctx *cctx;
+ zstd_dctx *dctx;
+ void *cctx_mem;
+ void *dctx_mem;
+ s32 level;
+};
+
+static void zstd_destroy(void *ctx)
+{
+ struct zstd_ctx *zctx = ctx;
+
+ vfree(zctx->cctx_mem);
+ vfree(zctx->dctx_mem);
+ kfree(zctx);
+}
+
+static void *zstd_create(void)
+{
+ zstd_parameters params;
+ struct zstd_ctx *ctx;
+ size_t sz;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ ctx->level = zstd_default_clevel();
+ params = zstd_get_params(ctx->level, 0);
+ sz = zstd_cctx_workspace_bound(¶ms.cParams);
+ ctx->cctx_mem = vzalloc(sz);
+ if (!ctx->cctx_mem)
+ goto error;
+
+ ctx->cctx = zstd_init_cctx(ctx->cctx_mem, sz);
+ if (!ctx->cctx)
+ goto error;
+
+ sz = zstd_dctx_workspace_bound();
+ ctx->dctx_mem = vzalloc(sz);
+ if (!ctx->dctx_mem)
+ goto error;
+
+ ctx->dctx = zstd_init_dctx(ctx->dctx_mem, sz);
+ if (!ctx->dctx)
+ goto error;
+
+ return ctx;
+
+error:
+ zstd_destroy(ctx);
+ return NULL;
+}
+
+static int zstd_compress(void *ctx, const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len)
+{
+ struct zstd_ctx *zctx = ctx;
+ const zstd_parameters params = zstd_get_params(zctx->level, 0);
+ size_t ret;
+
+ ret = zstd_compress_cctx(zctx->cctx, dst, *dst_len,
+ src, src_len, ¶ms);
+ if (zstd_is_error(ret))
+ return -EINVAL;
+ *dst_len = ret;
+ return 0;
+}
+
+static int zstd_decompress(void *ctx, const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t dst_len)
+{
+ struct zstd_ctx *zctx = ctx;
+ size_t ret;
+
+ ret = zstd_decompress_dctx(zctx->dctx, dst, dst_len, src, src_len);
+ if (zstd_is_error(ret))
+ return -EINVAL;
+ return 0;
+}
+
+const struct zcomp_ops backend_zstd = {
+ .compress = zstd_compress,
+ .decompress = zstd_decompress,
+ .create_ctx = zstd_create,
+ .destroy_ctx = zstd_destroy,
+ .name = "zstd",
+};
--- /dev/null
+++ a/drivers/block/zram/backend_zstd.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_ZSTD_H__
+#define __BACKEND_ZSTD_H__
+
+#include "zcomp.h"
+
+extern const struct zcomp_ops backend_zstd;
+
+#endif /* __BACKEND_ZSTD_H__ */
--- a/drivers/block/zram/Kconfig~zram-add-zstd-compression-backend-support
+++ a/drivers/block/zram/Kconfig
@@ -33,6 +33,12 @@ config ZRAM_BACKEND_LZ4HC
select LZ4HC_COMPRESS
select LZ4_DECOMPRESS
+config ZRAM_BACKEND_ZSTD
+ bool "zstd compression support"
+ depends on ZRAM
+ select ZSTD_COMPRESS
+ select ZSTD_DECOMPRESS
+
choice
prompt "Default zram compressor"
default ZRAM_DEF_COMP_LZORLE
@@ -54,6 +60,10 @@ config ZRAM_DEF_COMP_LZ4HC
bool "lz4hc"
depends on ZRAM_BACKEND_LZ4HC
+config ZRAM_DEF_COMP_ZSTD
+ bool "zstd"
+ depends on ZRAM_BACKEND_ZSTD
+
endchoice
config ZRAM_DEF_COMP
@@ -62,6 +72,7 @@ config ZRAM_DEF_COMP
default "lzo" if ZRAM_DEF_COMP_LZO
default "lz4" if ZRAM_DEF_COMP_LZ4
default "lz4hc" if ZRAM_DEF_COMP_LZ4HC
+ default "zstd" if ZRAM_DEF_COMP_ZSTD
default "unset-value"
config ZRAM_WRITEBACK
--- a/drivers/block/zram/Makefile~zram-add-zstd-compression-backend-support
+++ a/drivers/block/zram/Makefile
@@ -5,5 +5,6 @@ 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
zram-$(CONFIG_ZRAM_BACKEND_LZ4HC) += backend_lz4hc.o
+zram-$(CONFIG_ZRAM_BACKEND_ZSTD) += backend_zstd.o
obj-$(CONFIG_ZRAM) += zram.o
--- a/drivers/block/zram/zcomp.c~zram-add-zstd-compression-backend-support
+++ a/drivers/block/zram/zcomp.c
@@ -16,6 +16,7 @@
#include "backend_lzorle.h"
#include "backend_lz4.h"
#include "backend_lz4hc.h"
+#include "backend_zstd.h"
static const struct zcomp_ops *backends[] = {
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
@@ -28,6 +29,9 @@ static const struct zcomp_ops *backends[
#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4HC)
&backend_lz4hc,
#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_ZSTD)
+ &backend_zstd,
+#endif
NULL
};
_
Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are
lib-zstd-export-api-needed-for-dictionary-support.patch
lib-lz4hc-export-lz4_resetstreamhc-symbol.patch
lib-zstd-fix-null-deref-in-zstd_createcdict_advanced2.patch
zram-introduce-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_params-structure.patch
zram-recalculate-zstd-compression-params-once.patch
zram-extend-comp_algorithm-attr-write-handling.patch
zram-add-support-for-dict-comp-config.patch
zram-introduce-zcomp_req-structure.patch
zram-introduce-zcomp_ctx-structure.patch
zram-move-immutable-comp-params-away-from-per-cpu-context.patch
zram-add-dictionary-support-to-lz4.patch
zram-add-dictionary-support-to-lz4hc.patch
zram-add-dictionary-support-to-zstd-backend.patch
documentation-zram-add-documentation-for-algorithm-parameters.patch
