147e4937aSGao Xiang /* SPDX-License-Identifier: GPL-2.0-only */ 247e4937aSGao Xiang /* 347e4937aSGao Xiang * Copyright (C) 2019 HUAWEI, Inc. 4592e7cd0SAlexander A. Klimov * https://www.huawei.com/ 547e4937aSGao Xiang * Created by Gao Xiang <gaoxiang25@huawei.com> 647e4937aSGao Xiang */ 747e4937aSGao Xiang #ifndef __EROFS_FS_COMPRESS_H 847e4937aSGao Xiang #define __EROFS_FS_COMPRESS_H 947e4937aSGao Xiang 1047e4937aSGao Xiang #include "internal.h" 1147e4937aSGao Xiang 1247e4937aSGao Xiang enum { 1347e4937aSGao Xiang Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX, 1447e4937aSGao Xiang Z_EROFS_COMPRESSION_RUNTIME_MAX 1547e4937aSGao Xiang }; 1647e4937aSGao Xiang 1747e4937aSGao Xiang struct z_erofs_decompress_req { 1847e4937aSGao Xiang struct super_block *sb; 1947e4937aSGao Xiang struct page **in, **out; 2047e4937aSGao Xiang 2147e4937aSGao Xiang unsigned short pageofs_out; 2247e4937aSGao Xiang unsigned int inputsize, outputsize; 2347e4937aSGao Xiang 2447e4937aSGao Xiang /* indicate the algorithm will be used for decompression */ 2547e4937aSGao Xiang unsigned int alg; 2647e4937aSGao Xiang bool inplace_io, partial_decoding; 2747e4937aSGao Xiang }; 2847e4937aSGao Xiang 29*6aaa7b06SGao Xiang /* some special page->private (unsigned long, see below) */ 30*6aaa7b06SGao Xiang #define Z_EROFS_SHORTLIVED_PAGE (-1UL << 2) 31*6aaa7b06SGao Xiang 3247e4937aSGao Xiang /* 33*6aaa7b06SGao Xiang * For all pages in a pcluster, page->private should be one of 34*6aaa7b06SGao Xiang * Type Last 2bits page->private 35*6aaa7b06SGao Xiang * short-lived page 00 Z_EROFS_SHORTLIVED_PAGE 36*6aaa7b06SGao Xiang * cached/managed page 00 pointer to z_erofs_pcluster 37*6aaa7b06SGao Xiang * online page (file-backed, 01/10/11 sub-index << 2 | count 38*6aaa7b06SGao Xiang * some pages can be used for inplace I/O) 39*6aaa7b06SGao Xiang * 40*6aaa7b06SGao Xiang * page->mapping should be one of 41*6aaa7b06SGao Xiang * Type page->mapping 42*6aaa7b06SGao Xiang * short-lived page NULL 43*6aaa7b06SGao Xiang * cached/managed page non-NULL or NULL (invalidated/truncated page) 44*6aaa7b06SGao Xiang * online page non-NULL 45*6aaa7b06SGao Xiang * 46*6aaa7b06SGao Xiang * For all managed pages, PG_private should be set with 1 extra refcount, 47*6aaa7b06SGao Xiang * which is used for page reclaim / migration. 4847e4937aSGao Xiang */ 4947e4937aSGao Xiang 50*6aaa7b06SGao Xiang /* 51*6aaa7b06SGao Xiang * short-lived pages are pages directly from buddy system with specific 52*6aaa7b06SGao Xiang * page->private (no need to set PagePrivate since these are non-LRU / 53*6aaa7b06SGao Xiang * non-movable pages and bypass reclaim / migration code). 54*6aaa7b06SGao Xiang */ 55*6aaa7b06SGao Xiang static inline bool z_erofs_is_shortlived_page(struct page *page) 5647e4937aSGao Xiang { 57*6aaa7b06SGao Xiang if (page->private != Z_EROFS_SHORTLIVED_PAGE) 5847e4937aSGao Xiang return false; 5947e4937aSGao Xiang 60*6aaa7b06SGao Xiang DBG_BUGON(page->mapping); 61*6aaa7b06SGao Xiang return true; 62*6aaa7b06SGao Xiang } 63*6aaa7b06SGao Xiang 64*6aaa7b06SGao Xiang static inline bool z_erofs_put_shortlivedpage(struct list_head *pagepool, 65*6aaa7b06SGao Xiang struct page *page) 66*6aaa7b06SGao Xiang { 67*6aaa7b06SGao Xiang if (!z_erofs_is_shortlived_page(page)) 68*6aaa7b06SGao Xiang return false; 69*6aaa7b06SGao Xiang 70*6aaa7b06SGao Xiang /* short-lived pages should not be used by others at the same time */ 71*6aaa7b06SGao Xiang if (page_ref_count(page) > 1) { 7247e4937aSGao Xiang put_page(page); 73*6aaa7b06SGao Xiang } else { 74*6aaa7b06SGao Xiang /* follow the pcluster rule above. */ 75*6aaa7b06SGao Xiang set_page_private(page, 0); 7647e4937aSGao Xiang list_add(&page->lru, pagepool); 77*6aaa7b06SGao Xiang } 7847e4937aSGao Xiang return true; 7947e4937aSGao Xiang } 8047e4937aSGao Xiang 8147e4937aSGao Xiang int z_erofs_decompress(struct z_erofs_decompress_req *rq, 8247e4937aSGao Xiang struct list_head *pagepool); 8347e4937aSGao Xiang 8447e4937aSGao Xiang #endif 8547e4937aSGao Xiang 86