1 files changed, 99 insertions, 95 deletions

diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 8237b08c49d8..bb514403e305 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -1,7 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Copyright (C) 2014 Sergey Senozhatsky.
- */
 
 #include <linux/kernel.h>
 #include <linux/string.h>
@@ -15,91 +12,97 @@
 
 #include "zcomp.h"
 
-static const char * const backends[] = {
-#if IS_ENABLED(CONFIG_CRYPTO_LZO)
-	"lzo",
-	"lzo-rle",
+#include "backend_lzo.h"
+#include "backend_lzorle.h"
+#include "backend_lz4.h"
+#include "backend_lz4hc.h"
+#include "backend_zstd.h"
+#include "backend_deflate.h"
+#include "backend_842.h"
+
+static const struct zcomp_ops *backends[] = {
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZO)
+	&backend_lzorle,
+	&backend_lzo,
 #endif
-#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
-	"lz4",
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4)
+	&backend_lz4,
 #endif
-#if IS_ENABLED(CONFIG_CRYPTO_LZ4HC)
-	"lz4hc",
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_LZ4HC)
+	&backend_lz4hc,
 #endif
-#if IS_ENABLED(CONFIG_CRYPTO_842)
-	"842",
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_ZSTD)
+	&backend_zstd,
 #endif
-#if IS_ENABLED(CONFIG_CRYPTO_ZSTD)
-	"zstd",
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_DEFLATE)
+	&backend_deflate,
 #endif
+#if IS_ENABLED(CONFIG_ZRAM_BACKEND_842)
+	&backend_842,
+#endif
+	NULL
 };
 
-static void zcomp_strm_free(struct zcomp_strm *zstrm)
+static void zcomp_strm_free(struct zcomp *comp, struct zcomp_strm *zstrm)
 {
-	if (!IS_ERR_OR_NULL(zstrm->tfm))
-		crypto_free_comp(zstrm->tfm);
+	comp->ops->destroy_ctx(&zstrm->ctx);
 	vfree(zstrm->buffer);
-	zstrm->tfm = NULL;
 	zstrm->buffer = NULL;
 }
 
-/*
- * Initialize zcomp_strm structure with ->tfm initialized by backend, and
- * ->buffer. Return a negative value on error.
- */
-static int zcomp_strm_init(struct zcomp_strm *zstrm, struct zcomp *comp)
+static int zcomp_strm_init(struct zcomp *comp, struct zcomp_strm *zstrm)
 {
-	zstrm->tfm = crypto_alloc_comp(comp->name, 0, 0);
+	int ret;
+
+	ret = comp->ops->create_ctx(comp->params, &zstrm->ctx);
+	if (ret)
+		return ret;
+
 	/*
 	 * allocate 2 pages. 1 for compressed data, plus 1 extra for the
 	 * case when compressed size is larger than the original one
 	 */
 	zstrm->buffer = vzalloc(2 * PAGE_SIZE);
-	if (IS_ERR_OR_NULL(zstrm->tfm) || !zstrm->buffer) {
-		zcomp_strm_free(zstrm);
+	if (!zstrm->buffer) {
+		zcomp_strm_free(comp, zstrm);
 		return -ENOMEM;
 	}
 	return 0;
 }
 
+static const struct zcomp_ops *lookup_backend_ops(const char *comp)
+{
+	int i = 0;
+
+	while (backends[i]) {
+		if (sysfs_streq(comp, backends[i]->name))
+			break;
+		i++;
+	}
+	return backends[i];
+}
+
 bool zcomp_available_algorithm(const char *comp)
 {
-	/*
-	 * 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;
+	return lookup_backend_ops(comp) != NULL;
 }
 
 /* show available compressors */
 ssize_t zcomp_available_show(const char *comp, char *buf)
 {
-	bool known_algorithm = false;
 	ssize_t sz = 0;
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(backends); i++) {
-		if (!strcmp(comp, backends[i])) {
-			known_algorithm = true;
+	for (i = 0; i < ARRAY_SIZE(backends) - 1; i++) {
+		if (!strcmp(comp, backends[i]->name)) {
 			sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
-					"[%s] ", backends[i]);
+					"[%s] ", backends[i]->name);
 		} else {
 			sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
-					"%s ", backends[i]);
+					"%s ", backends[i]->name);
 		}
 	}
 
-	/*
-	 * 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;
 }
@@ -115,38 +118,34 @@ void zcomp_stream_put(struct zcomp *comp)
 	local_unlock(&comp->stream->lock);
 }
 
-int zcomp_compress(struct zcomp_strm *zstrm,
-		const void *src, unsigned int *dst_len)
+int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
+		   const void *src, unsigned int *dst_len)
 {
-	/*
-	 * 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;
+	struct zcomp_req req = {
+		.src = src,
+		.dst = zstrm->buffer,
+		.src_len = PAGE_SIZE,
+		.dst_len = 2 * PAGE_SIZE,
+	};
+	int ret;
 
-	return crypto_comp_compress(zstrm->tfm,
-			src, PAGE_SIZE,
-			zstrm->buffer, dst_len);
+	ret = comp->ops->compress(comp->params, &zstrm->ctx, &req);
+	if (!ret)
+		*dst_len = req.dst_len;
+	return ret;
 }
 
-int zcomp_decompress(struct zcomp_strm *zstrm,
-		const void *src, unsigned int src_len, void *dst)
+int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
+		     const void *src, unsigned int src_len, void *dst)
 {
-	unsigned int dst_len = PAGE_SIZE;
-
-	return crypto_comp_decompress(zstrm->tfm,
-			src, src_len,
-			dst, &dst_len);
+	struct zcomp_req req = {
+		.src = src,
+		.dst = dst,
+		.src_len = src_len,
+		.dst_len = PAGE_SIZE,
+	};
+
+	return comp->ops->decompress(comp->params, &zstrm->ctx, &req);
 }
 
 int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
@@ -158,7 +157,7 @@ int zcomp_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
 	zstrm = per_cpu_ptr(comp->stream, cpu);
 	local_lock_init(&zstrm->lock);
 
-	ret = zcomp_strm_init(zstrm, comp);
+	ret = zcomp_strm_init(comp, zstrm);
 	if (ret)
 		pr_err("Can't allocate a compression stream\n");
 	return ret;
@@ -170,11 +169,11 @@ int zcomp_cpu_dead(unsigned int cpu, struct hlist_node *node)
 	struct zcomp_strm *zstrm;
 
 	zstrm = per_cpu_ptr(comp->stream, cpu);
-	zcomp_strm_free(zstrm);
+	zcomp_strm_free(comp, zstrm);
 	return 0;
 }
 
-static int zcomp_init(struct zcomp *comp)
+static int zcomp_init(struct zcomp *comp, struct zcomp_params *params)
 {
 	int ret;
 
@@ -182,12 +181,19 @@ static int zcomp_init(struct zcomp *comp)
 	if (!comp->stream)
 		return -ENOMEM;
 
+	comp->params = params;
+	ret = comp->ops->setup_params(comp->params);
+	if (ret)
+		goto cleanup;
+
 	ret = cpuhp_state_add_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
 	if (ret < 0)
 		goto cleanup;
+
 	return 0;
 
 cleanup:
+	comp->ops->release_params(comp->params);
 	free_percpu(comp->stream);
 	return ret;
 }
@@ -195,37 +201,35 @@ cleanup:
 void zcomp_destroy(struct zcomp *comp)
 {
 	cpuhp_state_remove_instance(CPUHP_ZCOMP_PREPARE, &comp->node);
+	comp->ops->release_params(comp->params);
 	free_percpu(comp->stream);
 	kfree(comp);
 }
 
-/*
- * search available compressors for requested algorithm.
- * allocate new zcomp and initialize it. return compressing
- * backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL)
- * if requested algorithm is not supported, ERR_PTR(-ENOMEM) in
- * case of allocation error, or any other error potentially
- * returned by zcomp_init().
- */
-struct zcomp *zcomp_create(const char *alg)
+struct zcomp *zcomp_create(const char *alg, struct zcomp_params *params)
 {
 	struct zcomp *comp;
 	int error;
 
 	/*
-	 * Crypto API will execute /sbin/modprobe if the compression module
-	 * is not loaded yet. We must do it here, otherwise we are about to
-	 * call /sbin/modprobe under CPU hot-plug lock.
+	 * The backends array has a sentinel NULL value, so the minimum
+	 * size is 1. In order to be valid the array, apart from the
+	 * sentinel NULL element, should have at least one compression
+	 * backend selected.
 	 */
-	if (!zcomp_available_algorithm(alg))
-		return ERR_PTR(-EINVAL);
+	BUILD_BUG_ON(ARRAY_SIZE(backends) <= 1);
 
 	comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL);
 	if (!comp)
 		return ERR_PTR(-ENOMEM);
 
-	comp->name = alg;
-	error = zcomp_init(comp);
+	comp->ops = lookup_backend_ops(alg);
+	if (!comp->ops) {
+		kfree(comp);
+		return ERR_PTR(-EINVAL);
+	}
+
+	error = zcomp_init(comp, params);
 	if (error) {
 		kfree(comp);
 		return ERR_PTR(error);