1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2019 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 */ 6 #ifndef __EROFS_FS_COMPRESS_H 7 #define __EROFS_FS_COMPRESS_H 8 9 #include "internal.h" 10 11 struct z_erofs_decompress_req { 12 struct super_block *sb; 13 struct page **in, **out; 14 unsigned short pageofs_in, pageofs_out; 15 unsigned int inputsize, outputsize; 16 17 unsigned int alg; /* the algorithm for decompression */ 18 bool inplace_io, partial_decoding, fillgaps; 19 gfp_t gfp; /* allocation flags for extra temporary buffers */ 20 }; 21 22 struct z_erofs_decompressor { 23 int (*config)(struct super_block *sb, struct erofs_super_block *dsb, 24 void *data, int size); 25 int (*decompress)(struct z_erofs_decompress_req *rq, 26 struct page **pagepool); 27 int (*init)(void); 28 void (*exit)(void); 29 char *name; 30 }; 31 32 #define Z_EROFS_SHORTLIVED_PAGE (-1UL << 2) 33 #define Z_EROFS_PREALLOCATED_FOLIO ((void *)(-2UL << 2)) 34 35 /* 36 * Currently, short-lived pages are pages directly from buddy system 37 * with specific page->private (Z_EROFS_SHORTLIVED_PAGE). 38 * In the future world of Memdescs, it should be type 0 (Misc) memory 39 * which type can be checked with a new helper. 40 */ 41 static inline bool z_erofs_is_shortlived_page(struct page *page) 42 { 43 return page->private == Z_EROFS_SHORTLIVED_PAGE; 44 } 45 46 static inline bool z_erofs_put_shortlivedpage(struct page **pagepool, 47 struct page *page) 48 { 49 if (!z_erofs_is_shortlived_page(page)) 50 return false; 51 erofs_pagepool_add(pagepool, page); 52 return true; 53 } 54 55 extern const struct z_erofs_decompressor z_erofs_lzma_decomp; 56 extern const struct z_erofs_decompressor z_erofs_deflate_decomp; 57 extern const struct z_erofs_decompressor z_erofs_zstd_decomp; 58 extern const struct z_erofs_decompressor *z_erofs_decomp[]; 59 60 struct z_erofs_stream_dctx { 61 struct z_erofs_decompress_req *rq; 62 unsigned int inpages, outpages; /* # of {en,de}coded pages */ 63 int no, ni; /* the current {en,de}coded page # */ 64 65 unsigned int avail_out; /* remaining bytes in the decoded buffer */ 66 unsigned int inbuf_pos, inbuf_sz; 67 /* current status of the encoded buffer */ 68 u8 *kin, *kout; /* buffer mapped pointers */ 69 void *bounce; /* bounce buffer for inplace I/Os */ 70 bool bounced; /* is the bounce buffer used now? */ 71 }; 72 73 int z_erofs_stream_switch_bufs(struct z_erofs_stream_dctx *dctx, void **dst, 74 void **src, struct page **pgpl); 75 int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf, 76 unsigned int padbufsize); 77 int __init z_erofs_init_decompressor(void); 78 void z_erofs_exit_decompressor(void); 79 #endif 80