// SPDX-License-Identifier: GPL-2.0
/*
* f2fs compress support
*
* Copyright (c) 2019 Chao Yu <chao@kernel.org>
*/
#include <linux/fs.h>
#include <linux/f2fs_fs.h>
#include <linux/writeback.h>
#include <linux/backing-dev.h>
#include <linux/lzo.h>
#include <linux/lz4.h>
#include <linux/zstd.h>
#include "f2fs.h"
#include "node.h"
#include <trace/events/f2fs.h>
struct f2fs_compress_ops {
int (*init_compress_ctx)(struct compress_ctx *cc);
void (*destroy_compress_ctx)(struct compress_ctx *cc);
int (*compress_pages)(struct compress_ctx *cc);
int (*init_decompress_ctx)(struct decompress_io_ctx *dic);
void (*destroy_decompress_ctx)(struct decompress_io_ctx *dic);
int (*decompress_pages)(struct decompress_io_ctx *dic);
};
static unsigned int offset_in_cluster(struct compress_ctx *cc, pgoff_t index)
{
return index & (cc->cluster_size - 1);
}
static pgoff_t cluster_idx(struct compress_ctx *cc, pgoff_t index)
{
return index >> cc->log_cluster_size;
}
static pgoff_t start_idx_of_cluster(struct compress_ctx *cc)
{
return cc->cluster_idx << cc->log_cluster_size;
}
bool f2fs_is_compressed_page(struct page *page)
{
if (!PagePrivate(page))
return false;
if (!page_private(page))
return false;
if (IS_ATOMIC_WRITTEN_PAGE(page) || IS_DUMMY_WRITTEN_PAGE(page))
return false;
f2fs_bug_on(F2FS_M_SB(page->mapping),
*((u32 *)page_private(page)) != F2FS_COMPRESSED_PAGE_MAGIC);
return