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 */ 647e4937aSGao Xiang #ifndef __EROFS_FS_COMPRESS_H 747e4937aSGao Xiang #define __EROFS_FS_COMPRESS_H 847e4937aSGao Xiang 947e4937aSGao Xiang #include "internal.h" 1047e4937aSGao Xiang 1147e4937aSGao Xiang struct z_erofs_decompress_req { 1247e4937aSGao Xiang struct super_block *sb; 1347e4937aSGao Xiang struct page **in, **out; 1447e4937aSGao Xiang 1510e5f6e4SGao Xiang unsigned short pageofs_in, pageofs_out; 1647e4937aSGao Xiang unsigned int inputsize, outputsize; 1747e4937aSGao Xiang 1847e4937aSGao Xiang /* indicate the algorithm will be used for decompression */ 1947e4937aSGao Xiang unsigned int alg; 20267f2492SGao Xiang bool inplace_io, partial_decoding, fillgaps; 2147e4937aSGao Xiang }; 2247e4937aSGao Xiang 23622ceaddSGao Xiang struct z_erofs_decompressor { 24622ceaddSGao Xiang int (*decompress)(struct z_erofs_decompress_req *rq, 25eaa9172aSGao Xiang struct page **pagepool); 26622ceaddSGao Xiang char *name; 27622ceaddSGao Xiang }; 28622ceaddSGao Xiang 296aaa7b06SGao Xiang /* some special page->private (unsigned long, see below) */ 306aaa7b06SGao Xiang #define Z_EROFS_SHORTLIVED_PAGE (-1UL << 2) 311825c8d7SGao Xiang #define Z_EROFS_PREALLOCATED_PAGE (-2UL << 2) 326aaa7b06SGao Xiang 3347e4937aSGao Xiang /* 346aaa7b06SGao Xiang * For all pages in a pcluster, page->private should be one of 356aaa7b06SGao Xiang * Type Last 2bits page->private 366aaa7b06SGao Xiang * short-lived page 00 Z_EROFS_SHORTLIVED_PAGE 371825c8d7SGao Xiang * preallocated page (tryalloc) 00 Z_EROFS_PREALLOCATED_PAGE 386aaa7b06SGao Xiang * cached/managed page 00 pointer to z_erofs_pcluster 396aaa7b06SGao Xiang * online page (file-backed, 01/10/11 sub-index << 2 | count 406aaa7b06SGao Xiang * some pages can be used for inplace I/O) 416aaa7b06SGao Xiang * 426aaa7b06SGao Xiang * page->mapping should be one of 436aaa7b06SGao Xiang * Type page->mapping 446aaa7b06SGao Xiang * short-lived page NULL 451825c8d7SGao Xiang * preallocated page NULL 466aaa7b06SGao Xiang * cached/managed page non-NULL or NULL (invalidated/truncated page) 476aaa7b06SGao Xiang * online page non-NULL 486aaa7b06SGao Xiang * 496aaa7b06SGao Xiang * For all managed pages, PG_private should be set with 1 extra refcount, 506aaa7b06SGao Xiang * which is used for page reclaim / migration. 5147e4937aSGao Xiang */ 5247e4937aSGao Xiang 536aaa7b06SGao Xiang /* 546aaa7b06SGao Xiang * short-lived pages are pages directly from buddy system with specific 556aaa7b06SGao Xiang * page->private (no need to set PagePrivate since these are non-LRU / 566aaa7b06SGao Xiang * non-movable pages and bypass reclaim / migration code). 576aaa7b06SGao Xiang */ 586aaa7b06SGao Xiang static inline bool z_erofs_is_shortlived_page(struct page *page) 5947e4937aSGao Xiang { 606aaa7b06SGao Xiang if (page->private != Z_EROFS_SHORTLIVED_PAGE) 6147e4937aSGao Xiang return false; 6247e4937aSGao Xiang 636aaa7b06SGao Xiang DBG_BUGON(page->mapping); 646aaa7b06SGao Xiang return true; 656aaa7b06SGao Xiang } 666aaa7b06SGao Xiang 67eaa9172aSGao Xiang static inline bool z_erofs_put_shortlivedpage(struct page **pagepool, 686aaa7b06SGao Xiang struct page *page) 696aaa7b06SGao Xiang { 706aaa7b06SGao Xiang if (!z_erofs_is_shortlived_page(page)) 716aaa7b06SGao Xiang return false; 726aaa7b06SGao Xiang 736aaa7b06SGao Xiang /* short-lived pages should not be used by others at the same time */ 746aaa7b06SGao Xiang if (page_ref_count(page) > 1) { 7547e4937aSGao Xiang put_page(page); 766aaa7b06SGao Xiang } else { 776aaa7b06SGao Xiang /* follow the pcluster rule above. */ 78eaa9172aSGao Xiang erofs_pagepool_add(pagepool, page); 796aaa7b06SGao Xiang } 8047e4937aSGao Xiang return true; 8147e4937aSGao Xiang } 8247e4937aSGao Xiang 83622ceaddSGao Xiang #define MNGD_MAPPING(sbi) ((sbi)->managed_cache->i_mapping) 84622ceaddSGao Xiang static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi, 85622ceaddSGao Xiang struct page *page) 86622ceaddSGao Xiang { 87622ceaddSGao Xiang return page->mapping == MNGD_MAPPING(sbi); 88622ceaddSGao Xiang } 89622ceaddSGao Xiang 9010e5f6e4SGao Xiang int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf, 9110e5f6e4SGao Xiang unsigned int padbufsize); 92*597e2953SYue Hu extern const struct z_erofs_decompressor erofs_decompressors[]; 9347e4937aSGao Xiang 94622ceaddSGao Xiang /* prototypes for specific algorithms */ 95622ceaddSGao Xiang int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq, 96eaa9172aSGao Xiang struct page **pagepool); 9747e4937aSGao Xiang #endif 98