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 static inline struct btrfs_fs_info *cb_to_fs_info(const struct compressed_bio *cb) 79 { 80 return cb->bbio.fs_info; 81 } 82 83 /* @range_end must be exclusive. */ 84 static inline u32 btrfs_calc_input_length(struct folio *folio, u64 range_end, u64 cur) 85 { 86 /* @cur must be inside the folio. */ 87 ASSERT(folio_pos(folio) <= cur); 88 ASSERT(cur < folio_end(folio)); 89 return min(range_end, folio_end(folio)) - cur; 90 } 91 92 int btrfs_alloc_compress_wsm(struct btrfs_fs_info *fs_info); 93 void btrfs_free_compress_wsm(struct btrfs_fs_info *fs_info); 94 95 int __init btrfs_init_compress(void); 96 void __cold btrfs_exit_compress(void); 97 98 bool btrfs_compress_level_valid(unsigned int type, int level); 99 int btrfs_compress_folios(unsigned int type, int level, struct btrfs_inode *inode, 100 u64 start, struct folio **folios, unsigned long *out_folios, 101 unsigned long *total_in, unsigned long *total_out); 102 int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio, 103 unsigned long start_byte, size_t srclen, size_t destlen); 104 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 105 struct compressed_bio *cb, u32 decompressed); 106 107 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, 108 struct folio **compressed_folios, 109 unsigned int nr_folios, blk_opf_t write_flags, 110 bool writeback); 111 void btrfs_submit_compressed_read(struct btrfs_bio *bbio); 112 113 int btrfs_compress_str2level(unsigned int type, const char *str, int *level_ret); 114 115 struct folio *btrfs_alloc_compr_folio(struct btrfs_fs_info *fs_info); 116 void btrfs_free_compr_folio(struct folio *folio); 117 118 struct workspace_manager { 119 struct list_head idle_ws; 120 spinlock_t ws_lock; 121 /* Number of free workspaces */ 122 int free_ws; 123 /* Total number of allocated workspaces */ 124 atomic_t total_ws; 125 /* Waiters for a free workspace */ 126 wait_queue_head_t ws_wait; 127 }; 128 129 struct list_head *btrfs_get_workspace(struct btrfs_fs_info *fs_info, int type, int level); 130 void btrfs_put_workspace(struct btrfs_fs_info *fs_info, int type, struct list_head *ws); 131 132 struct btrfs_compress_levels { 133 /* Maximum level supported by the compression algorithm */ 134 int min_level; 135 int max_level; 136 int default_level; 137 }; 138 139 /* The heuristic workspaces are managed via the 0th workspace manager */ 140 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 141 142 extern const struct btrfs_compress_levels btrfs_heuristic_compress; 143 extern const struct btrfs_compress_levels btrfs_zlib_compress; 144 extern const struct btrfs_compress_levels btrfs_lzo_compress; 145 extern const struct btrfs_compress_levels btrfs_zstd_compress; 146 147 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 148 bool btrfs_compress_is_valid_type(const char *str, size_t len); 149 150 int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end); 151 152 int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start, 153 struct folio **in_folio_ret); 154 155 int zlib_compress_folios(struct list_head *ws, struct btrfs_inode *inode, 156 u64 start, struct folio **folios, unsigned long *out_folios, 157 unsigned long *total_in, unsigned long *total_out); 158 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 159 int zlib_decompress(struct list_head *ws, const u8 *data_in, 160 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 161 size_t destlen); 162 struct list_head *zlib_alloc_workspace(struct btrfs_fs_info *fs_info, unsigned int level); 163 void zlib_free_workspace(struct list_head *ws); 164 struct list_head *zlib_get_workspace(struct btrfs_fs_info *fs_info, unsigned int level); 165 166 int lzo_compress_folios(struct list_head *ws, struct btrfs_inode *inode, 167 u64 start, struct folio **folios, unsigned long *out_folios, 168 unsigned long *total_in, unsigned long *total_out); 169 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 170 int lzo_decompress(struct list_head *ws, const u8 *data_in, 171 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 172 size_t destlen); 173 struct list_head *lzo_alloc_workspace(struct btrfs_fs_info *fs_info); 174 void lzo_free_workspace(struct list_head *ws); 175 176 int zstd_compress_folios(struct list_head *ws, struct btrfs_inode *inode, 177 u64 start, struct folio **folios, unsigned long *out_folios, 178 unsigned long *total_in, unsigned long *total_out); 179 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 180 int zstd_decompress(struct list_head *ws, const u8 *data_in, 181 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 182 size_t destlen); 183 int zstd_alloc_workspace_manager(struct btrfs_fs_info *fs_info); 184 void zstd_free_workspace_manager(struct btrfs_fs_info *fs_info); 185 struct list_head *zstd_alloc_workspace(struct btrfs_fs_info *fs_info, int level); 186 void zstd_free_workspace(struct list_head *ws); 187 struct list_head *zstd_get_workspace(struct btrfs_fs_info *fs_info, int level); 188 void zstd_put_workspace(struct btrfs_fs_info *fs_info, struct list_head *ws); 189 190 #endif 191