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-rw-r--r--drivers/block/zram/Kconfig10
-rw-r--r--drivers/block/zram/zcomp.c76
-rw-r--r--drivers/block/zram/zcomp.h17
-rw-r--r--drivers/block/zram/zram_drv.c18
4 files changed, 69 insertions, 52 deletions
diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 386ba3d1a6ee..2252cd7d0e89 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, ...).
@@ -18,9 +17,8 @@ config ZRAM
config ZRAM_LZ4_COMPRESS
bool "Enable LZ4 algorithm support"
depends on ZRAM
- select LZ4_COMPRESS
- select LZ4_DECOMPRESS
+ select CRYPTO_LZ4
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
+ algorithm can be changed using `comp_algorithm' device attribute.
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 400f8267337e..f35726860a1b 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -14,42 +14,39 @@
#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,
+static const char * const backends[] = {
+ "lzo",
#ifdef CONFIG_ZRAM_LZ4_COMPRESS
- &zcomp_lz4,
+ "lz4",
#endif
NULL
};
-static struct zcomp_backend *find_backend(const char *compress)
+static const char *find_backend(const char *compress)
{
int i = 0;
while (backends[i]) {
- if (sysfs_streq(compress, backends[i]->name))
+ if (sysfs_streq(compress, backends[i]))
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)
@@ -58,14 +55,14 @@ static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp, gfp_t flags)
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);
+ if (IS_ERR_OR_NULL(zstrm->tfm) || !zstrm->buffer) {
+ zcomp_strm_free(zstrm);
zstrm = NULL;
}
return zstrm;
@@ -78,12 +75,12 @@ ssize_t zcomp_available_show(const char *comp, char *buf)
int i = 0;
while (backends[i]) {
- if (!strcmp(comp, backends[i]->name))
+ if (!strcmp(comp, backends[i]))
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
- "[%s] ", backends[i]->name);
+ "[%s] ", backends[i]);
else
sz += scnprintf(buf + sz, PAGE_SIZE - sz - 2,
- "%s ", backends[i]->name);
+ "%s ", backends[i]);
i++;
}
sz += scnprintf(buf + sz, PAGE_SIZE - sz, "\n");
@@ -105,17 +102,38 @@ 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,
@@ -138,7 +156,7 @@ 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:
@@ -209,7 +227,7 @@ void zcomp_destroy(struct zcomp *comp)
struct zcomp *zcomp_create(const char *compress)
{
struct zcomp *comp;
- struct zcomp_backend *backend;
+ const char *backend;
int error;
backend = find_backend(compress);
@@ -220,7 +238,7 @@ struct zcomp *zcomp_create(const char *compress)
if (!comp)
return ERR_PTR(-ENOMEM);
- comp->backend = backend;
+ comp->name = backend;
error = zcomp_init(comp);
if (error) {
kfree(comp);
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 944b8e60dd82..c914ab7972ef 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -13,12 +13,7 @@
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;
+ struct crypto_comp *tfm;
};
/* static compression backend */
@@ -40,6 +35,8 @@ 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);
@@ -51,11 +48,11 @@ void zcomp_destroy(struct zcomp *comp);
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/zram_drv.c b/drivers/block/zram/zram_drv.c
index 9361a5db7de8..65d140336289 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -563,7 +563,7 @@ 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 +576,14 @@ 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 +650,7 @@ 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;
@@ -696,7 +700,7 @@ compress_again:
}
zstrm = zcomp_stream_get(zram->comp);
- ret = zcomp_compress(zram->comp, zstrm, uncmem, &clen);
+ ret = zcomp_compress(zstrm, uncmem, &clen);
if (!is_partial_io(bvec)) {
kunmap_atomic(user_mem);
user_mem = NULL;
@@ -744,7 +748,7 @@ compress_again:
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;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.