1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2008 Oracle. All rights reserved. 4 */ 5 6 #ifndef BTRFS_COMPRESSION_H 7 #define BTRFS_COMPRESSION_H 8 9 #include <linux/sizes.h> 10 #include <linux/mm.h> 11 #include <linux/list.h> 12 #include <linux/workqueue.h> 13 #include <linux/wait.h> 14 #include "bio.h" 15 16 struct address_space; 17 struct page; 18 struct inode; 19 struct btrfs_inode; 20 struct btrfs_ordered_extent; 21 struct btrfs_bio; 22 23 /* 24 * We want to make sure that amount of RAM required to uncompress an extent is 25 * reasonable, so we limit the total size in ram of a compressed extent to 26 * 128k. This is a crucial number because it also controls how easily we can 27 * spread reads across cpus for decompression. 28 * 29 * We also want to make sure the amount of IO required to do a random read is 30 * reasonably small, so we limit the size of a compressed extent to 128k. 31 */ 32 33 /* Maximum length of compressed data stored on disk */ 34 #define BTRFS_MAX_COMPRESSED (SZ_128K) 35 #define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE) 36 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0); 37 38 /* Maximum size of data before compression */ 39 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K) 40 41 #define BTRFS_ZLIB_DEFAULT_LEVEL 3 42 43 struct compressed_bio { 44 /* Number of compressed folios in the array. */ 45 unsigned int nr_folios; 46 47 /* The folios with the compressed data on them. */ 48 struct folio **compressed_folios; 49 50 /* starting offset in the inode for our pages */ 51 u64 start; 52 53 /* Number of bytes in the inode we're working on */ 54 unsigned int len; 55 56 /* Number of bytes on disk */ 57 unsigned int compressed_len; 58 59 /* The compression algorithm for this bio */ 60 u8 compress_type; 61 62 /* Whether this is a write for writeback. */ 63 bool writeback; 64 65 union { 66 /* For reads, this is the bio we are copying the data into */ 67 struct btrfs_bio *orig_bbio; 68 struct work_struct write_end_work; 69 }; 70 71 /* Must be last. */ 72 struct btrfs_bio bbio; 73 }; 74 75 static inline unsigned int btrfs_compress_type(unsigned int type_level) 76 { 77 return (type_level & 0xF); 78 } 79 80 static inline unsigned int btrfs_compress_level(unsigned int type_level) 81 { 82 return ((type_level & 0xF0) >> 4); 83 } 84 85 /* @range_end must be exclusive. */ 86 static inline u32 btrfs_calc_input_length(u64 range_end, u64 cur) 87 { 88 u64 page_end = round_down(cur, PAGE_SIZE) + PAGE_SIZE; 89 90 return min(range_end, page_end) - cur; 91 } 92 93 int __init btrfs_init_compress(void); 94 void __cold btrfs_exit_compress(void); 95 96 int btrfs_compress_folios(unsigned int type_level, struct address_space *mapping, 97 u64 start, struct folio **folios, unsigned long *out_folios, 98 unsigned long *total_in, unsigned long *total_out); 99 int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio, 100 unsigned long start_byte, size_t srclen, size_t destlen); 101 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 102 struct compressed_bio *cb, u32 decompressed); 103 104 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, 105 struct folio **compressed_folios, 106 unsigned int nr_folios, blk_opf_t write_flags, 107 bool writeback); 108 void btrfs_submit_compressed_read(struct btrfs_bio *bbio); 109 110 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 111 112 struct folio *btrfs_alloc_compr_folio(void); 113 void btrfs_free_compr_folio(struct folio *folio); 114 115 enum btrfs_compression_type { 116 BTRFS_COMPRESS_NONE = 0, 117 BTRFS_COMPRESS_ZLIB = 1, 118 BTRFS_COMPRESS_LZO = 2, 119 BTRFS_COMPRESS_ZSTD = 3, 120 BTRFS_NR_COMPRESS_TYPES = 4, 121 }; 122 123 struct workspace_manager { 124 struct list_head idle_ws; 125 spinlock_t ws_lock; 126 /* Number of free workspaces */ 127 int free_ws; 128 /* Total number of allocated workspaces */ 129 atomic_t total_ws; 130 /* Waiters for a free workspace */ 131 wait_queue_head_t ws_wait; 132 }; 133 134 struct list_head *btrfs_get_workspace(int type, unsigned int level); 135 void btrfs_put_workspace(int type, struct list_head *ws); 136 137 struct btrfs_compress_op { 138 struct workspace_manager *workspace_manager; 139 /* Maximum level supported by the compression algorithm */ 140 unsigned int max_level; 141 unsigned int default_level; 142 }; 143 144 /* The heuristic workspaces are managed via the 0th workspace manager */ 145 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 146 147 extern const struct btrfs_compress_op btrfs_heuristic_compress; 148 extern const struct btrfs_compress_op btrfs_zlib_compress; 149 extern const struct btrfs_compress_op btrfs_lzo_compress; 150 extern const struct btrfs_compress_op btrfs_zstd_compress; 151 152 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 153 bool btrfs_compress_is_valid_type(const char *str, size_t len); 154 155 int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end); 156 157 int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start, 158 struct folio **in_folio_ret); 159 160 int zlib_compress_folios(struct list_head *ws, struct address_space *mapping, 161 u64 start, struct folio **folios, unsigned long *out_folios, 162 unsigned long *total_in, unsigned long *total_out); 163 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 164 int zlib_decompress(struct list_head *ws, const u8 *data_in, 165 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 166 size_t destlen); 167 struct list_head *zlib_alloc_workspace(unsigned int level); 168 void zlib_free_workspace(struct list_head *ws); 169 struct list_head *zlib_get_workspace(unsigned int level); 170 171 int lzo_compress_folios(struct list_head *ws, struct address_space *mapping, 172 u64 start, struct folio **folios, unsigned long *out_folios, 173 unsigned long *total_in, unsigned long *total_out); 174 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 175 int lzo_decompress(struct list_head *ws, const u8 *data_in, 176 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 177 size_t destlen); 178 struct list_head *lzo_alloc_workspace(unsigned int level); 179 void lzo_free_workspace(struct list_head *ws); 180 181 int zstd_compress_folios(struct list_head *ws, struct address_space *mapping, 182 u64 start, struct folio **folios, unsigned long *out_folios, 183 unsigned long *total_in, unsigned long *total_out); 184 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 185 int zstd_decompress(struct list_head *ws, const u8 *data_in, 186 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 187 size_t destlen); 188 void zstd_init_workspace_manager(void); 189 void zstd_cleanup_workspace_manager(void); 190 struct list_head *zstd_alloc_workspace(unsigned int level); 191 void zstd_free_workspace(struct list_head *ws); 192 struct list_head *zstd_get_workspace(unsigned int level); 193 void zstd_put_workspace(struct list_head *ws); 194 195 #endif 196