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