10 files changed, 138 insertions, 266 deletions

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 386ba3d1a6ee..b8ecba6dcd3b 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -1,8 +1,7 @@
 config ZRAM
 	tristate "Compressed RAM block device support"
-	depends on BLOCK && SYSFS && ZSMALLOC
-	select LZO_COMPRESS
-	select LZO_DECOMPRESS
+	depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO
+	select CRYPTO_LZO
 	default n
 	help
 	  Creates virtual block devices called /dev/zramX (X = 0, 1, ...).
@@ -14,13 +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 LZ4_COMPRESS
-	select LZ4_DECOMPRESS
-	default n
-	help
-	  This option enables LZ4 compression algorithm support. Compression
-	  algorithm can be changed using `comp_algorithm' device attribute.
\ No newline at end of file
diff --git a/drivers/block/zram/Makefile b/drivers/block/zram/Makefile
index be0763ff57a2..9e2b79e9a990 100644
--- a/drivers/block/zram/Makefile
+++ b/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
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index b51a816d766b..4b5cd3a7b2b6 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -14,108 +14,150 @@
 #include <linux/wait.h>
 #include <linux/sched.h>
 #include <linux/cpu.h>
+#include <linux/crypto.h>
 
 #include "zcomp.h"
-#include "zcomp_lzo.h"
-#ifdef CONFIG_ZRAM_LZ4_COMPRESS
-#include "zcomp_lz4.h"
-#endif
 
-static struct zcomp_backend *backends[] = {
-	&zcomp_lzo,
-#ifdef CONFIG_ZRAM_LZ4_COMPRESS
-	&zcomp_lz4,
+static const char * const backends[] = {
+	"lzo",
+#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
+	"lz4",
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_DEFLATE)
+	"deflate",
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_LZ4HC)
+	"lz4hc",
+#endif
+#if IS_ENABLED(CONFIG_CRYPTO_842)
+	"842",
 #endif
 	NULL
 };
 
-static struct zcomp_backend *find_backend(const char *compress)
-{
-	int i = 0;
-	while (backends[i]) {
-		if (sysfs_streq(compress, backends[i]->name))
-			break;
-		i++;
-	}
-	return backends[i];
-}
-
-static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
+static void zcomp_strm_free(struct zcomp_strm *zstrm)
 {
-	if (zstrm->private)
-		comp->backend->destroy(zstrm->private);
+	if (!IS_ERR_OR_NULL(zstrm->tfm))
+		crypto_free_comp(zstrm->tfm);
 	free_pages((unsigned long)zstrm->buffer, 1);
 	kfree(zstrm);
 }
 
 /*
- * allocate new zcomp_strm structure with ->private initialized by
+ * allocate new zcomp_strm structure with ->tfm initialized by
  * backend, return NULL on error
  */
-static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp, gfp_t flags)
+static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp)
 {
-	struct zcomp_strm *zstrm = kmalloc(sizeof(*zstrm), flags);
+	struct zcomp_strm *zstrm = kmalloc(sizeof(*zstrm), GFP_KERNEL);
 	if (!zstrm)
 		return NULL;
 
-	zstrm->private = comp->backend->create(flags);
+	zstrm->tfm = crypto_alloc_comp(comp->name, 0, 0);
 	/*
 	 * allocate 2 pages. 1 for compressed data, plus 1 extra for the
 	 * case when compressed size is larger than the original one
 	 */
-	zstrm->buffer = (void *)__get_free_pages(flags | __GFP_ZERO, 1);
-	if (!zstrm->private || !zstrm->buffer) {
-		zcomp_strm_free(comp, zstrm);
+	zstrm->buffer = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
+	if (IS_ERR_OR_NULL(zstrm->tfm) || !zstrm->buffer) {
+		zcomp_strm_free(zstrm);
 		zstrm = NULL;
 	}
 	return zstrm;
 }
 
+bool zcomp_available_algorithm(const char *comp)
+{
+	int i = 0;
+
+	while (backends[i]) {
+		if (sysfs_streq(comp, backends[i]))
+			return true;
+		i++;
+	}
+
+	/*
+	 * Crypto does not ignore a trailing new line symbol,
+	 * so make sure you don't supply a string containing
+	 * one.
+	 * This also means that we permit zcomp initialisation
+	 * with any compressing algorithm known to crypto api.
+	 */
+	return crypto_has_comp(comp, 0, 0) == 1;
+}
+
 /* show available compressors */
 ssize_t zcomp_available_show(const char *comp, char *buf)
 {
+	bool known_algorithm = false;
 	ssize_t sz = 0;
 	int i = 0;
 
-	while (backends[i]) {
-		if (!strcmp(comp, backends[i]->name))
+	for (; backends[i]; i++) {
+		if (!strcmp(comp, backends[i])) {
+			known_algorithm = true;
 			sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
-					"[%s] ", backends[i]->name);
-		else
+					"[%s] ", backends[i]);
+		} else {
 			sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
-					"%s ", backends[i]->name);
-		i++;
+					"%s ", backends[i]);
+		}
 	}
+
+	/*
+	 * Out-of-tree module known to crypto api or a missing
+	 * entry in `backends'.
+	 */
+	if (!known_algorithm && crypto_has_comp(comp, 0, 0) == 1)
+		sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
+				"[%s] ", comp);
+
 	sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
 	return sz;
 }
 
-bool zcomp_available_algorithm(const char *comp)
-{
-	return find_backend(comp) != NULL;
-}
-
-struct zcomp_strm *zcomp_strm_find(struct zcomp *comp)
+struct zcomp_strm *zcomp_stream_get(struct zcomp *comp)
 {
 	return *get_cpu_ptr(comp->stream);
 }
 
-void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm)
+void zcomp_stream_put(struct zcomp *comp)
 {
 	put_cpu_ptr(comp->stream);
 }
 
-int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
-		const unsigned char *src, size_t *dst_len)
+int zcomp_compress(struct zcomp_strm *zstrm,
+		const void *src, unsigned int *dst_len)
 {
-	return comp->backend->compress(src, zstrm->buffer, dst_len,
-			zstrm->private);
+	/*
+	 * Our dst memory (zstrm->buffer) is always `2 * PAGE_SIZE' sized
+	 * because sometimes we can endup having a bigger compressed data
+	 * due to various reasons: for example compression algorithms tend
+	 * to add some padding to the compressed buffer. Speaking of padding,
+	 * comp algorithm `842' pads the compressed length to multiple of 8
+	 * and returns -ENOSP when the dst memory is not big enough, which
+	 * is not something that ZRAM wants to see. We can handle the
+	 * `compressed_size > PAGE_SIZE' case easily in ZRAM, but when we
+	 * receive -ERRNO from the compressing backend we can't help it
+	 * anymore. To make `842' happy we need to tell the exact size of
+	 * the dst buffer, zram_drv will take care of the fact that
+	 * compressed buffer is too big.
+	 */
+	*dst_len = PAGE_SIZE * 2;
+
+	return crypto_comp_compress(zstrm->tfm,
+			src, PAGE_SIZE,
+			zstrm->buffer, dst_len);
 }
 
-int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
-		size_t src_len, unsigned char *dst)
+int zcomp_decompress(struct zcomp_strm *zstrm,
+		const void *src, unsigned int src_len, void *dst)
 {
-	return comp->backend->decompress(src, src_len, dst);
+	unsigned int dst_len = PAGE_SIZE;
+
+	return crypto_comp_decompress(zstrm->tfm,
+			src, src_len,
+			dst, &dst_len);
 }
 
 static int __zcomp_cpu_notifier(struct zcomp *comp,
@@ -127,7 +169,7 @@ static int __zcomp_cpu_notifier(struct zcomp *comp,
 	case CPU_UP_PREPARE:
 		if (WARN_ON(*per_cpu_ptr(comp->stream, cpu)))
 			break;
-		zstrm = zcomp_strm_alloc(comp, GFP_KERNEL);
+		zstrm = zcomp_strm_alloc(comp);
 		if (IS_ERR_OR_NULL(zstrm)) {
 			pr_err("Can't allocate a compression stream\n");
 			return NOTIFY_BAD;
@@ -138,7 +180,7 @@ static int __zcomp_cpu_notifier(struct zcomp *comp,
 	case CPU_UP_CANCELED:
 		zstrm = *per_cpu_ptr(comp->stream, cpu);
 		if (!IS_ERR_OR_NULL(zstrm))
-			zcomp_strm_free(comp, zstrm);
+			zcomp_strm_free(zstrm);
 		*per_cpu_ptr(comp->stream, cpu) = NULL;
 		break;
 	default:
@@ -209,18 +251,16 @@ void zcomp_destroy(struct zcomp *comp)
 struct zcomp *zcomp_create(const char *compress)
 {
 	struct zcomp *comp;
-	struct zcomp_backend *backend;
 	int error;
 
-	backend = find_backend(compress);
-	if (!backend)
+	if (!zcomp_available_algorithm(compress))
 		return ERR_PTR(-EINVAL);
 
 	comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL);
 	if (!comp)
 		return ERR_PTR(-ENOMEM);
 
-	comp->backend = backend;
+	comp->name = compress;
 	error = zcomp_init(comp);
 	if (error) {
 		kfree(comp);
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index ffd88cb747fe..478cac2ed465 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -13,33 +13,15 @@
 struct zcomp_strm {
 	/* compression/decompression buffer */
 	void *buffer;
-	/*
-	 * The private data of the compression stream, only compression
-	 * stream backend can touch this (e.g. compression algorithm
-	 * working memory)
-	 */
-	void *private;
-};
-
-/* 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;
+	struct crypto_comp *tfm;
 };
 
 /* dynamic per-device compression frontend */
 struct zcomp {
 	struct zcomp_strm * __percpu *stream;
-	struct zcomp_backend *backend;
 	struct notifier_block notifier;
+
+	const char *name;
 };
 
 ssize_t zcomp_available_show(const char *comp, char *buf);
@@ -48,14 +30,14 @@ bool zcomp_available_algorithm(const char *comp);
 struct zcomp *zcomp_create(const char *comp);
 void zcomp_destroy(struct zcomp *comp);
 
-struct zcomp_strm *zcomp_strm_find(struct zcomp *comp);
-void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm);
+struct zcomp_strm *zcomp_stream_get(struct zcomp *comp);
+void zcomp_stream_put(struct zcomp *comp);
 
-int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
-		const unsigned char *src, size_t *dst_len);
+int zcomp_compress(struct zcomp_strm *zstrm,
+		const void *src, unsigned int *dst_len);
 
-int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
-		size_t src_len, unsigned char *dst);
+int zcomp_decompress(struct zcomp_strm *zstrm,
+		const void *src, unsigned int src_len, void *dst);
 
 bool zcomp_set_max_streams(struct zcomp *comp, int num_strm);
 #endif /* _ZCOMP_H_ */
diff --git a/drivers/block/zram/zcomp_lz4.c b/drivers/block/zram/zcomp_lz4.c
deleted file mode 100644
index 0110086accba..000000000000
--- a/drivers/block/zram/zcomp_lz4.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/lz4.h>
-#include <linux/vmalloc.h>
-#include <linux/mm.h>
-
-#include "zcomp_lz4.h"
-
-static void *zcomp_lz4_create(gfp_t flags)
-{
-	void *ret;
-
-	ret = kmalloc(LZ4_MEM_COMPRESS, flags);
-	if (!ret)
-		ret = __vmalloc(LZ4_MEM_COMPRESS,
-				flags | __GFP_HIGHMEM,
-				PAGE_KERNEL);
-	return ret;
-}
-
-static void zcomp_lz4_destroy(void *private)
-{
-	kvfree(private);
-}
-
-static int zcomp_lz4_compress(const unsigned char *src, unsigned char *dst,
-		size_t *dst_len, void *private)
-{
-	/* return  : Success if return 0 */
-	return lz4_compress(src, PAGE_SIZE, dst, dst_len, private);
-}
-
-static int zcomp_lz4_decompress(const unsigned char *src, size_t src_len,
-		unsigned char *dst)
-{
-	size_t dst_len = PAGE_SIZE;
-	/* return  : Success if return 0 */
-	return lz4_decompress_unknownoutputsize(src, src_len, dst, &dst_len);
-}
-
-struct zcomp_backend zcomp_lz4 = {
-	.compress = zcomp_lz4_compress,
-	.decompress = zcomp_lz4_decompress,
-	.create = zcomp_lz4_create,
-	.destroy = zcomp_lz4_destroy,
-	.name = "lz4",
-};
diff --git a/drivers/block/zram/zcomp_lz4.h b/drivers/block/zram/zcomp_lz4.h
deleted file mode 100644
index 60613fb29dd8..000000000000
--- a/drivers/block/zram/zcomp_lz4.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#ifndef _ZCOMP_LZ4_H_
-#define _ZCOMP_LZ4_H_
-
-#include "zcomp.h"
-
-extern struct zcomp_backend zcomp_lz4;
-
-#endif /* _ZCOMP_LZ4_H_ */
diff --git a/drivers/block/zram/zcomp_lzo.c b/drivers/block/zram/zcomp_lzo.c
deleted file mode 100644
index ed7a1f0549ec..000000000000
--- a/drivers/block/zram/zcomp_lzo.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/lzo.h>
-#include <linux/vmalloc.h>
-#include <linux/mm.h>
-
-#include "zcomp_lzo.h"
-
-static void *lzo_create(gfp_t flags)
-{
-	void *ret;
-
-	ret = kmalloc(LZO1X_MEM_COMPRESS, flags);
-	if (!ret)
-		ret = __vmalloc(LZO1X_MEM_COMPRESS,
-				flags | __GFP_HIGHMEM,
-				PAGE_KERNEL);
-	return ret;
-}
-
-static void lzo_destroy(void *private)
-{
-	kvfree(private);
-}
-
-static int lzo_compress(const unsigned char *src, unsigned char *dst,
-		size_t *dst_len, void *private)
-{
-	int ret = lzo1x_1_compress(src, PAGE_SIZE, dst, dst_len, private);
-	return ret == LZO_E_OK ? 0 : ret;
-}
-
-static int lzo_decompress(const unsigned char *src, size_t src_len,
-		unsigned char *dst)
-{
-	size_t dst_len = PAGE_SIZE;
-	int ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
-	return ret == LZO_E_OK ? 0 : ret;
-}
-
-struct zcomp_backend zcomp_lzo = {
-	.compress = lzo_compress,
-	.decompress = lzo_decompress,
-	.create = lzo_create,
-	.destroy = lzo_destroy,
-	.name = "lzo",
-};
diff --git a/drivers/block/zram/zcomp_lzo.h b/drivers/block/zram/zcomp_lzo.h
deleted file mode 100644
index 128c5807fa14..000000000000
--- a/drivers/block/zram/zcomp_lzo.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#ifndef _ZCOMP_LZO_H_
-#define _ZCOMP_LZO_H_
-
-#include "zcomp.h"
-
-extern struct zcomp_backend zcomp_lzo;
-
-#endif /* _ZCOMP_LZO_H_ */
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index e5e5d19f2172..7454cf188c8e 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -342,9 +342,16 @@ static ssize_t comp_algorithm_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t len)
 {
 	struct zram *zram = dev_to_zram(dev);
+	char compressor[CRYPTO_MAX_ALG_NAME];
 	size_t sz;
 
-	if (!zcomp_available_algorithm(buf))
+	strlcpy(compressor, buf, sizeof(compressor));
+	/* ignore trailing newline */
+	sz = strlen(compressor);
+	if (sz > 0 && compressor[sz - 1] == '\n')
+		compressor[sz - 1] = 0x00;
+
+	if (!zcomp_available_algorithm(compressor))
 		return -EINVAL;
 
 	down_write(&zram->init_lock);
@@ -353,13 +360,8 @@ static ssize_t comp_algorithm_store(struct device *dev,
 		pr_info("Can't change algorithm for initialized device\n");
 		return -EBUSY;
 	}
-	strlcpy(zram->compressor, buf, sizeof(zram->compressor));
-
-	/* ignore trailing newline */
-	sz = strlen(zram->compressor);
-	if (sz > 0 && zram->compressor[sz - 1] == '\n')
-		zram->compressor[sz - 1] = 0x00;
 
+	strlcpy(zram->compressor, compressor, sizeof(compressor));
 	up_write(&zram->init_lock);
 	return len;
 }
@@ -563,7 +565,7 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
 	unsigned char *cmem;
 	struct zram_meta *meta = zram->meta;
 	unsigned long handle;
-	size_t size;
+	unsigned int size;
 
 	bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
 	handle = meta->table[index].handle;
@@ -576,10 +578,14 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
 	}
 
 	cmem = zs_map_object(meta->mem_pool, handle, ZS_MM_RO);
-	if (size == PAGE_SIZE)
+	if (size == PAGE_SIZE) {
 		copy_page(mem, cmem);
-	else
-		ret = zcomp_decompress(zram->comp, cmem, size, mem);
+	} else {
+		struct zcomp_strm *zstrm = zcomp_stream_get(zram->comp);
+
+		ret = zcomp_decompress(zstrm, cmem, size, mem);
+		zcomp_stream_put(zram->comp);
+	}
 	zs_unmap_object(meta->mem_pool, handle);
 	bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);
 
@@ -646,7 +652,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
 			   int offset)
 {
 	int ret = 0;
-	size_t clen;
+	unsigned int clen;
 	unsigned long handle = 0;
 	struct page *page;
 	unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
@@ -695,8 +701,8 @@ compress_again:
 		goto out;
 	}
 
-	zstrm = zcomp_strm_find(zram->comp);
-	ret = zcomp_compress(zram->comp, zstrm, uncmem, &clen);
+	zstrm = zcomp_stream_get(zram->comp);
+	ret = zcomp_compress(zstrm, uncmem, &clen);
 	if (!is_partial_io(bvec)) {
 		kunmap_atomic(user_mem);
 		user_mem = NULL;
@@ -732,19 +738,21 @@ compress_again:
 		handle = zs_malloc(meta->mem_pool, clen,
 				__GFP_KSWAPD_RECLAIM |
 				__GFP_NOWARN |
-				__GFP_HIGHMEM);
+				__GFP_HIGHMEM |
+				__GFP_MOVABLE);
 	if (!handle) {
-		zcomp_strm_release(zram->comp, zstrm);
+		zcomp_stream_put(zram->comp);
 		zstrm = NULL;
 
 		atomic64_inc(&zram->stats.writestall);
 
 		handle = zs_malloc(meta->mem_pool, clen,
-				GFP_NOIO | __GFP_HIGHMEM);
+				GFP_NOIO | __GFP_HIGHMEM |
+				__GFP_MOVABLE);
 		if (handle)
 			goto compress_again;
 
-		pr_err("Error allocating memory for compressed page: %u, size=%zu\n",
+		pr_err("Error allocating memory for compressed page: %u, size=%u\n",
 			index, clen);
 		ret = -ENOMEM;
 		goto out;
@@ -769,7 +777,7 @@ compress_again:
 		memcpy(cmem, src, clen);
 	}
 
-	zcomp_strm_release(zram->comp, zstrm);
+	zcomp_stream_put(zram->comp);
 	zstrm = NULL;
 	zs_unmap_object(meta->mem_pool, handle);
 
@@ -789,7 +797,7 @@ compress_again:
 	atomic64_inc(&zram->stats.pages_stored);
 out:
 	if (zstrm)
-		zcomp_strm_release(zram->comp, zstrm);
+		zcomp_stream_put(zram->comp);
 	if (is_partial_io(bvec))
 		kfree(uncmem);
 	return ret;
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 3f5bf66a27e4..74fcf10da374 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -15,8 +15,9 @@
 #ifndef _ZRAM_DRV_H_
 #define _ZRAM_DRV_H_
 
-#include <linux/spinlock.h>
+#include <linux/rwsem.h>
 #include <linux/zsmalloc.h>
+#include <linux/crypto.h>
 
 #include "zcomp.h"
 
@@ -113,7 +114,7 @@ struct zram {
 	 * we can store in a disk.
 	 */
 	u64 disksize;	/* bytes */
-	char compressor[10];
+	char compressor[CRYPTO_MAX_ALG_NAME];
 	/*
 	 * zram is claimed so open request will be failed
 	 */