mirror of https://gitee.com/openkylin/linux.git
61 lines
1.4 KiB
C
61 lines
1.4 KiB
C
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/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2019 HUAWEI, Inc.
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* http://www.huawei.com/
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* Created by Gao Xiang <gaoxiang25@huawei.com>
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*/
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#ifndef __EROFS_FS_COMPRESS_H
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#define __EROFS_FS_COMPRESS_H
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#include "internal.h"
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enum {
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Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
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Z_EROFS_COMPRESSION_RUNTIME_MAX
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};
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struct z_erofs_decompress_req {
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struct super_block *sb;
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struct page **in, **out;
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unsigned short pageofs_out;
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unsigned int inputsize, outputsize;
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/* indicate the algorithm will be used for decompression */
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unsigned int alg;
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bool inplace_io, partial_decoding;
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};
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/*
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* - 0x5A110C8D ('sallocated', Z_EROFS_MAPPING_STAGING) -
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* used to mark temporary allocated pages from other
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* file/cached pages and NULL mapping pages.
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*/
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#define Z_EROFS_MAPPING_STAGING ((void *)0x5A110C8D)
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/* check if a page is marked as staging */
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static inline bool z_erofs_page_is_staging(struct page *page)
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{
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return page->mapping == Z_EROFS_MAPPING_STAGING;
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}
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static inline bool z_erofs_put_stagingpage(struct list_head *pagepool,
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struct page *page)
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{
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if (!z_erofs_page_is_staging(page))
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return false;
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/* staging pages should not be used by others at the same time */
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if (page_ref_count(page) > 1)
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put_page(page);
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else
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list_add(&page->lru, pagepool);
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return true;
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}
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int z_erofs_decompress(struct z_erofs_decompress_req *rq,
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struct list_head *pagepool);
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#endif
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