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 struct btrfs_ordered_extent; 14 15 /* 16 * We want to make sure that amount of RAM required to uncompress an extent is 17 * reasonable, so we limit the total size in ram of a compressed extent to 18 * 128k. This is a crucial number because it also controls how easily we can 19 * spread reads across cpus for decompression. 20 * 21 * We also want to make sure the amount of IO required to do a random read is 22 * reasonably small, so we limit the size of a compressed extent to 128k. 23 */ 24 25 /* Maximum length of compressed data stored on disk */ 26 #define BTRFS_MAX_COMPRESSED (SZ_128K) 27 #define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE) 28 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0); 29 30 /* Maximum size of data before compression */ 31 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K) 32 33 #define BTRFS_ZLIB_DEFAULT_LEVEL 3 34 35 struct page; 36 37 struct compressed_bio { 38 /* Number of compressed pages in the array */ 39 unsigned int nr_pages; 40 41 /* the pages with the compressed data on them */ 42 struct page **compressed_pages; 43 44 /* starting offset in the inode for our pages */ 45 u64 start; 46 47 /* Number of bytes in the inode we're working on */ 48 unsigned int len; 49 50 /* Number of bytes on disk */ 51 unsigned int compressed_len; 52 53 /* The compression algorithm for this bio */ 54 u8 compress_type; 55 56 /* Whether this is a write for writeback. */ 57 bool writeback; 58 59 union { 60 /* For reads, this is the bio we are copying the data into */ 61 struct btrfs_bio *orig_bbio; 62 struct work_struct write_end_work; 63 }; 64 65 /* Must be last. */ 66 struct btrfs_bio bbio; 67 }; 68 69 static inline unsigned int btrfs_compress_type(unsigned int type_level) 70 { 71 return (type_level & 0xF); 72 } 73 74 static inline unsigned int btrfs_compress_level(unsigned int type_level) 75 { 76 return ((type_level & 0xF0) >> 4); 77 } 78 79 int __init btrfs_init_compress(void); 80 void __cold btrfs_exit_compress(void); 81 82 int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, 83 u64 start, struct page **pages, 84 unsigned long *out_pages, 85 unsigned long *total_in, 86 unsigned long *total_out); 87 int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, 88 unsigned long start_byte, size_t srclen, size_t destlen); 89 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 90 struct compressed_bio *cb, u32 decompressed); 91 92 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, 93 struct page **compressed_pages, 94 unsigned int nr_pages, 95 blk_opf_t write_flags, 96 bool writeback); 97 void btrfs_submit_compressed_read(struct btrfs_bio *bbio); 98 99 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 100 101 struct page *btrfs_alloc_compr_page(void); 102 void btrfs_free_compr_page(struct page *page); 103 104 enum btrfs_compression_type { 105 BTRFS_COMPRESS_NONE = 0, 106 BTRFS_COMPRESS_ZLIB = 1, 107 BTRFS_COMPRESS_LZO = 2, 108 BTRFS_COMPRESS_ZSTD = 3, 109 BTRFS_NR_COMPRESS_TYPES = 4, 110 }; 111 112 struct workspace_manager { 113 struct list_head idle_ws; 114 spinlock_t ws_lock; 115 /* Number of free workspaces */ 116 int free_ws; 117 /* Total number of allocated workspaces */ 118 atomic_t total_ws; 119 /* Waiters for a free workspace */ 120 wait_queue_head_t ws_wait; 121 }; 122 123 struct list_head *btrfs_get_workspace(int type, unsigned int level); 124 void btrfs_put_workspace(int type, struct list_head *ws); 125 126 struct btrfs_compress_op { 127 struct workspace_manager *workspace_manager; 128 /* Maximum level supported by the compression algorithm */ 129 unsigned int max_level; 130 unsigned int default_level; 131 }; 132 133 /* The heuristic workspaces are managed via the 0th workspace manager */ 134 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 135 136 extern const struct btrfs_compress_op btrfs_heuristic_compress; 137 extern const struct btrfs_compress_op btrfs_zlib_compress; 138 extern const struct btrfs_compress_op btrfs_lzo_compress; 139 extern const struct btrfs_compress_op btrfs_zstd_compress; 140 141 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 142 bool btrfs_compress_is_valid_type(const char *str, size_t len); 143 144 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); 145 146 int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, 147 u64 start, struct page **pages, unsigned long *out_pages, 148 unsigned long *total_in, unsigned long *total_out); 149 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 150 int zlib_decompress(struct list_head *ws, const u8 *data_in, 151 struct page *dest_page, unsigned long dest_pgoff, size_t srclen, 152 size_t destlen); 153 struct list_head *zlib_alloc_workspace(unsigned int level); 154 void zlib_free_workspace(struct list_head *ws); 155 struct list_head *zlib_get_workspace(unsigned int level); 156 157 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, 158 u64 start, struct page **pages, unsigned long *out_pages, 159 unsigned long *total_in, unsigned long *total_out); 160 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 161 int lzo_decompress(struct list_head *ws, const u8 *data_in, 162 struct page *dest_page, unsigned long dest_pgoff, size_t srclen, 163 size_t destlen); 164 struct list_head *lzo_alloc_workspace(unsigned int level); 165 void lzo_free_workspace(struct list_head *ws); 166 167 int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, 168 u64 start, struct page **pages, unsigned long *out_pages, 169 unsigned long *total_in, unsigned long *total_out); 170 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 171 int zstd_decompress(struct list_head *ws, const u8 *data_in, 172 struct page *dest_page, unsigned long start_byte, size_t srclen, 173 size_t destlen); 174 void zstd_init_workspace_manager(void); 175 void zstd_cleanup_workspace_manager(void); 176 struct list_head *zstd_alloc_workspace(unsigned int level); 177 void zstd_free_workspace(struct list_head *ws); 178 struct list_head *zstd_get_workspace(unsigned int level); 179 void zstd_put_workspace(struct list_head *ws); 180 181 #endif 182