Introduce zcomp_decompress_begin()/zcomp_decompress_end() as a
preparation for crypto API-powered zcomp.
Change zcomp_decompress() signature to require zstrm parameter.
Unlike zcomp_compress_begin(), zcomp_decompress_begin() may return
zstrm if currently selected compression backend require zstrm for
decompression or NULL if it does not.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
---
drivers/block/zram/zcomp.c | 3 ++-
drivers/block/zram/zcomp.h | 3 ++-
drivers/block/zram/zram_drv.c | 20 ++++++++++++++++----
3 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index 52d5b04..e3016da 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -336,7 +336,8 @@ int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
zstrm->private);
}
-int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
+int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const unsigned char *src,
size_t src_len, unsigned char *dst)
{
return comp->backend->decompress(src, src_len, dst);
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index 616e013..4c09c01 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -66,7 +66,8 @@ int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
struct zcomp_strm *zcomp_decompress_begin(struct zcomp *comp);
void zcomp_decompress_end(struct zcomp *comp, struct zcomp_strm *zstrm);
-int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
+int zcomp_decompress(struct zcomp *comp, struct zcomp_strm *zstrm,
+ const unsigned char *src,
size_t src_len, unsigned char *dst);
bool zcomp_set_max_streams(struct zcomp *comp, int num_strm);
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 7dda8a5..74cbb81 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -560,7 +560,8 @@ static void zram_free_page(struct zram *zram, size_t index)
zram_set_obj_size(meta, index, 0);
}
-static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
+static int zram_decompress_page(struct zram *zram, struct zcomp_strm *zstrm,
+ char *mem, u32 index)
{
int ret = 0;
unsigned char *cmem;
@@ -582,7 +583,7 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
if (size == PAGE_SIZE)
copy_page(mem, cmem);
else
- ret = zcomp_decompress(zram->comp, cmem, size, mem);
+ ret = zcomp_decompress(zram->comp, zstrm, cmem, size, mem);
zs_unmap_object(meta->mem_pool, handle);
bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value);
@@ -602,6 +603,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
struct page *page;
unsigned char *user_mem, *uncmem = NULL;
struct zram_meta *meta = zram->meta;
+ struct zcomp_strm *zstrm;
page = bvec->bv_page;
bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value);
@@ -617,6 +619,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
/* Use a temporary buffer to decompress the page */
uncmem = kmalloc(PAGE_SIZE, GFP_NOIO);
+ zstrm = zcomp_decompress_begin(zram->comp);
user_mem = kmap_atomic(page);
if (!is_partial_io(bvec))
uncmem = user_mem;
@@ -627,7 +630,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
goto out_cleanup;
}
- ret = zram_decompress_page(zram, uncmem, index);
+ ret = zram_decompress_page(zram, zstrm, uncmem, index);
/* Should NEVER happen. Return bio error if it does. */
if (unlikely(ret))
goto out_cleanup;
@@ -636,10 +639,14 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
memcpy(user_mem + bvec->bv_offset, uncmem + offset,
bvec->bv_len);
+ zcomp_decompress_end(zram->comp, zstrm);
+ zstrm = NULL;
+
flush_dcache_page(page);
ret = 0;
out_cleanup:
kunmap_atomic(user_mem);
+ zcomp_decompress_end(zram->comp, zstrm);
if (is_partial_io(bvec))
kfree(uncmem);
return ret;
@@ -659,6 +666,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
page = bvec->bv_page;
if (is_partial_io(bvec)) {
+ struct zcomp_strm *zstrm;
/*
* This is a partial IO. We need to read the full page
* before to write the changes.
@@ -668,7 +676,11 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
ret = -ENOMEM;
goto out;
}
- ret = zram_decompress_page(zram, uncmem, index);
+
+ zstrm = zcomp_decompress_begin(zram->comp);
+ ret = zram_decompress_page(zram, zstrm, uncmem, index);
+ zcomp_decompress_end(zram->comp, zstrm);
+
if (ret)
goto out;
}
--
2.6.0.rc2.10.gf4d9753
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