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