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 int __init btrfs_init_compress(void); 86 void __cold btrfs_exit_compress(void); 87 88 int btrfs_compress_folios(unsigned int type_level, struct address_space *mapping, 89 u64 start, struct folio **folios, unsigned long *out_folios, 90 unsigned long *total_in, unsigned long *total_out); 91 int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, 92 unsigned long start_byte, size_t srclen, size_t destlen); 93 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 94 struct compressed_bio *cb, u32 decompressed); 95 96 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, 97 struct folio **compressed_folios, 98 unsigned int nr_folios, blk_opf_t write_flags, 99 bool writeback); 100 void btrfs_submit_compressed_read(struct btrfs_bio *bbio); 101 102 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 103 104 struct folio *btrfs_alloc_compr_folio(void); 105 void btrfs_free_compr_folio(struct folio *folio); 106 107 enum btrfs_compression_type { 108 BTRFS_COMPRESS_NONE = 0, 109 BTRFS_COMPRESS_ZLIB = 1, 110 BTRFS_COMPRESS_LZO = 2, 111 BTRFS_COMPRESS_ZSTD = 3, 112 BTRFS_NR_COMPRESS_TYPES = 4, 113 }; 114 115 struct workspace_manager { 116 struct list_head idle_ws; 117 spinlock_t ws_lock; 118 /* Number of free workspaces */ 119 int free_ws; 120 /* Total number of allocated workspaces */ 121 atomic_t total_ws; 122 /* Waiters for a free workspace */ 123 wait_queue_head_t ws_wait; 124 }; 125 126 struct list_head *btrfs_get_workspace(int type, unsigned int level); 127 void btrfs_put_workspace(int type, struct list_head *ws); 128 129 struct btrfs_compress_op { 130 struct workspace_manager *workspace_manager; 131 /* Maximum level supported by the compression algorithm */ 132 unsigned int max_level; 133 unsigned int default_level; 134 }; 135 136 /* The heuristic workspaces are managed via the 0th workspace manager */ 137 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 138 139 extern const struct btrfs_compress_op btrfs_heuristic_compress; 140 extern const struct btrfs_compress_op btrfs_zlib_compress; 141 extern const struct btrfs_compress_op btrfs_lzo_compress; 142 extern const struct btrfs_compress_op btrfs_zstd_compress; 143 144 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 145 bool btrfs_compress_is_valid_type(const char *str, size_t len); 146 147 int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end); 148 149 int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start, 150 struct folio **in_folio_ret); 151 152 int zlib_compress_folios(struct list_head *ws, struct address_space *mapping, 153 u64 start, struct folio **folios, unsigned long *out_folios, 154 unsigned long *total_in, unsigned long *total_out); 155 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 156 int zlib_decompress(struct list_head *ws, const u8 *data_in, 157 struct page *dest_page, unsigned long dest_pgoff, size_t srclen, 158 size_t destlen); 159 struct list_head *zlib_alloc_workspace(unsigned int level); 160 void zlib_free_workspace(struct list_head *ws); 161 struct list_head *zlib_get_workspace(unsigned int level); 162 163 int lzo_compress_folios(struct list_head *ws, struct address_space *mapping, 164 u64 start, struct folio **folios, unsigned long *out_folios, 165 unsigned long *total_in, unsigned long *total_out); 166 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 167 int lzo_decompress(struct list_head *ws, const u8 *data_in, 168 struct page *dest_page, unsigned long dest_pgoff, size_t srclen, 169 size_t destlen); 170 struct list_head *lzo_alloc_workspace(unsigned int level); 171 void lzo_free_workspace(struct list_head *ws); 172 173 int zstd_compress_folios(struct list_head *ws, struct address_space *mapping, 174 u64 start, struct folio **folios, unsigned long *out_folios, 175 unsigned long *total_in, unsigned long *total_out); 176 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 177 int zstd_decompress(struct list_head *ws, const u8 *data_in, 178 struct page *dest_page, unsigned long dest_pgoff, size_t srclen, 179 size_t destlen); 180 void zstd_init_workspace_manager(void); 181 void zstd_cleanup_workspace_manager(void); 182 struct list_head *zstd_alloc_workspace(unsigned int level); 183 void zstd_free_workspace(struct list_head *ws); 184 struct list_head *zstd_get_workspace(unsigned int level); 185 void zstd_put_workspace(struct list_head *ws); 186 187 #endif 188