zram: add zlib compression backend support

Add s/w zlib (inflate/deflate) compression.

Link: https://lkml.kernel.org/r/20240902105656.1383858-11-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 71cd0d5d8f350ef686b22d8035d34ef493aeaa12..9dedd2edfb285b15381f20f9b6e7560f9b5fd259 100644 (file)
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -38,6 +38,12 @@ config ZRAM_BACKEND_ZSTD
        select ZSTD_COMPRESS
        select ZSTD_DECOMPRESS
 
+config ZRAM_BACKEND_DEFLATE
+       bool "deflate compression support"
+       depends on ZRAM
+       select ZLIB_DEFLATE
+       select ZLIB_INFLATE
+
 choice
        prompt "Default zram compressor"
        default ZRAM_DEF_COMP_LZORLE
@@ -63,6 +69,10 @@ config ZRAM_DEF_COMP_ZSTD
        bool "zstd"
        depends on ZRAM_BACKEND_ZSTD
 
+config ZRAM_DEF_COMP_DEFLATE
+       bool "deflate"
+       depends on ZRAM_BACKEND_DEFLATE
+
 endchoice
 
 config ZRAM_DEF_COMP
@@ -72,6 +82,7 @@ config ZRAM_DEF_COMP
        default "lz4" if ZRAM_DEF_COMP_LZ4
        default "lz4hc" if ZRAM_DEF_COMP_LZ4HC
        default "zstd" if ZRAM_DEF_COMP_ZSTD
+       default "deflate" if ZRAM_DEF_COMP_DEFLATE
        default "unset-value"
 
 config ZRAM_WRITEBACK

diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index a2ca227e199ca70b3676c0a35157343fa862fdd8..26643054843741e8cd941500662985ce4a62f634 100644 (file)
--- a/drivers/block/zram/Makefile
+++ b/drivers/block/zram/Makefile
@@ -6,5 +6,6 @@ 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
+zram-$(CONFIG_ZRAM_BACKEND_DEFLATE)    += backend_deflate.o
 
 obj-$(CONFIG_ZRAM)     +=      zram.o

diff --git a/drivers/block/zram/backend_deflate.c b/drivers/block/zram/backend_deflate.c
new file mode 100644 (file)
index 0000000..acefb86
--- /dev/null
+++ b/drivers/block/zram/backend_deflate.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/zlib.h>
+
+#include "backend_deflate.h"
+
+/* Use the same value as crypto API */
+#define DEFLATE_DEF_WINBITS            11
+#define DEFLATE_DEF_MEMLEVEL           MAX_MEM_LEVEL
+
+struct deflate_ctx {
+       struct z_stream_s cctx;
+       struct z_stream_s dctx;
+       s32 level;
+};
+
+static void deflate_destroy(void *ctx)
+{
+       struct deflate_ctx *zctx = ctx;
+
+       if (zctx->cctx.workspace) {
+               zlib_deflateEnd(&zctx->cctx);
+               vfree(zctx->cctx.workspace);
+       }
+       if (zctx->dctx.workspace) {
+               zlib_inflateEnd(&zctx->dctx);
+               vfree(zctx->dctx.workspace);
+       }
+       kfree(zctx);
+}
+
+static void *deflate_create(void)
+{
+       struct deflate_ctx *ctx;
+       size_t sz;
+       int ret;
+
+       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
+               return NULL;
+
+       /* @FIXME: using a hardcoded Z_DEFAULT_COMPRESSION for now */
+       ctx->level = Z_DEFAULT_COMPRESSION;
+       sz = zlib_deflate_workspacesize(-DEFLATE_DEF_WINBITS, MAX_MEM_LEVEL);
+       ctx->cctx.workspace = vzalloc(sz);
+       if (!ctx->cctx.workspace)
+               goto error;
+
+       ret = zlib_deflateInit2(&ctx->cctx, ctx->level, Z_DEFLATED,
+                               -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
+                               Z_DEFAULT_STRATEGY);
+       if (ret != Z_OK)
+               goto error;
+
+       sz = zlib_inflate_workspacesize();
+       ctx->dctx.workspace = vzalloc(sz);
+       if (!ctx->dctx.workspace)
+               goto error;
+
+       ret = zlib_inflateInit2(&ctx->dctx, -DEFLATE_DEF_WINBITS);
+       if (ret != Z_OK)
+               goto error;
+
+       return ctx;
+
+error:
+       deflate_destroy(ctx);
+       return NULL;
+}
+
+static int deflate_compress(void *ctx, const unsigned char *src,
+                           size_t src_len, unsigned char *dst,
+                           size_t *dst_len)
+{
+       struct deflate_ctx *zctx = ctx;
+       struct z_stream_s *deflate;
+       int ret;
+
+       deflate = &zctx->cctx;
+       ret = zlib_deflateReset(deflate);
+       if (ret != Z_OK)
+               return -EINVAL;
+
+       deflate->next_in = (u8 *)src;
+       deflate->avail_in = src_len;
+       deflate->next_out = (u8 *)dst;
+       deflate->avail_out = *dst_len;
+
+       ret = zlib_deflate(deflate, Z_FINISH);
+       if (ret != Z_STREAM_END)
+               return -EINVAL;
+
+       *dst_len = deflate->total_out;
+       return 0;
+}
+
+static int deflate_decompress(void *ctx, const unsigned char *src,
+                             size_t src_len, unsigned char *dst,
+                             size_t dst_len)
+{
+       struct deflate_ctx *zctx = ctx;
+       struct z_stream_s *inflate;
+       int ret;
+
+       inflate = &zctx->dctx;
+
+       ret = zlib_inflateReset(inflate);
+       if (ret != Z_OK)
+               return -EINVAL;
+
+       inflate->next_in = (u8 *)src;
+       inflate->avail_in = src_len;
+       inflate->next_out = (u8 *)dst;
+       inflate->avail_out = dst_len;
+
+       ret = zlib_inflate(inflate, Z_SYNC_FLUSH);
+       if (ret != Z_STREAM_END)
+               return -EINVAL;
+
+       return 0;
+}
+
+const struct zcomp_ops backend_deflate = {
+       .compress       = deflate_compress,
+       .decompress     = deflate_decompress,
+       .create_ctx     = deflate_create,
+       .destroy_ctx    = deflate_destroy,
+       .name           = "deflate",
+};

diff --git a/drivers/block/zram/backend_deflate.h b/drivers/block/zram/backend_deflate.h
new file mode 100644 (file)
index 0000000..a39ac12
--- /dev/null
+++ b/drivers/block/zram/backend_deflate.h
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#ifndef __BACKEND_DEFLATE_H__
+#define __BACKEND_DEFLATE_H__
+
+#include "zcomp.h"
+
+extern const struct zcomp_ops backend_deflate;
+
+#endif /* __BACKEND_DEFLATE_H__ */

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 07147659f4a2db10556e33d7e85691520bdfc13e..d1396fe82b1db05c759f8b1abf04465d43df61c1 100644 (file)
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -17,6 +17,7 @@
 #include "backend_lz4.h"
 #include "backend_lz4hc.h"
 #include "backend_zstd.h"
+#include "backend_deflate.h"
 
 static const struct zcomp_ops *backends[] = {
 #if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
@@ -31,6 +32,9 @@ static const struct zcomp_ops *backends[] = {
 #endif
 #if IS_ENABLED(CONFIG_ZRAM_BACKEND_ZSTD)
        &backend_zstd,
+#endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_DEFLATE)
+       &backend_deflate,
 #endif
        NULL
 };