zram: delete custom lzo/lz4

Remove lzo/lz4 backends, we use crypto API now.

[[email protected]: zram-delete-custom-lzo-lz4-v3]
  Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Sergey Senozhatsky <[email protected]>
Acked-by: Minchan Kim <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: sergey-senozhatsky

drivers/block/zram/Kconfig

@@ -13,12 +13,3 @@ config ZRAM
 	  disks and maybe many more.
 
 	  See zram.txt for more information.
-
-config ZRAM_LZ4_COMPRESS
-	bool "Enable LZ4 algorithm support"
-	depends on ZRAM
-	select CRYPTO_LZ4
-	default n
-	help
-	  This option enables LZ4 compression algorithm support. Compression
-	  algorithm can be changed using `comp_algorithm' device attribute.

drivers/block/zram/Makefile

@@ -1,5 +1,3 @@
-zram-y	:=	zcomp_lzo.o zcomp.o zram_drv.o
-
-zram-$(CONFIG_ZRAM_LZ4_COMPRESS) += zcomp_lz4.o
+zram-y	:=	zcomp.o zram_drv.o
 
 obj-$(CONFIG_ZRAM)	+=	zram.o

drivers/block/zram/zcomp.c

@@ -20,7 +20,7 @@
 
 static const char * const backends[] = {
 	"lzo",
-#ifdef CONFIG_ZRAM_LZ4_COMPRESS
+#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
 	"lz4",
 #endif
 	NULL

drivers/block/zram/zcomp.h

@@ -16,24 +16,9 @@ struct zcomp_strm {
 	struct crypto_comp *tfm;
 };
 
-/* static compression backend */
-struct zcomp_backend {
-	int (*compress)(const unsigned char *src, unsigned char *dst,
-			size_t *dst_len, void *private);
-
-	int (*decompress)(const unsigned char *src, size_t src_len,
-			unsigned char *dst);
-
-	void *(*create)(gfp_t flags);
-	void (*destroy)(void *private);
-
-	const char *name;
-};
-
 /* dynamic per-device compression frontend */
 struct zcomp {
 	struct zcomp_strm * __percpu *stream;
-	struct zcomp_backend *backend;
 	struct notifier_block notifier;
 
 	const char *name;