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