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/blk_types.h> 10 #include <linux/sizes.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 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0); 27 28 /* Maximum size of data before compression */ 29 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K) 30 31 #define BTRFS_ZLIB_DEFAULT_LEVEL 3 32 33 struct compressed_bio { 34 /* Number of compressed pages in the array */ 35 unsigned int nr_pages; 36 37 /* the pages with the compressed data on them */ 38 struct page **compressed_pages; 39 40 /* inode that owns this data */ 41 struct inode *inode; 42 43 /* starting offset in the inode for our pages */ 44 u64 start; 45 46 /* Number of bytes in the inode we're working on */ 47 unsigned int len; 48 49 /* Number of bytes on disk */ 50 unsigned int compressed_len; 51 52 /* The compression algorithm for this bio */ 53 u8 compress_type; 54 55 /* Whether this is a write for writeback. */ 56 bool writeback; 57 58 /* IO errors */ 59 blk_status_t status; 60 61 union { 62 /* For reads, this is the bio we are copying the data into */ 63 struct bio *orig_bio; 64 struct work_struct write_end_work; 65 }; 66 }; 67 68 static inline unsigned int btrfs_compress_type(unsigned int type_level) 69 { 70 return (type_level & 0xF); 71 } 72 73 static inline unsigned int btrfs_compress_level(unsigned int type_level) 74 { 75 return ((type_level & 0xF0) >> 4); 76 } 77 78 int __init btrfs_init_compress(void); 79 void __cold btrfs_exit_compress(void); 80 81 int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, 82 u64 start, struct page **pages, 83 unsigned long *out_pages, 84 unsigned long *total_in, 85 unsigned long *total_out); 86 int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, 87 unsigned long start_byte, size_t srclen, size_t destlen); 88 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 89 struct compressed_bio *cb, u32 decompressed); 90 91 blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 92 unsigned int len, u64 disk_start, 93 unsigned int compressed_len, 94 struct page **compressed_pages, 95 unsigned int nr_pages, 96 blk_opf_t write_flags, 97 struct cgroup_subsys_state *blkcg_css, 98 bool writeback); 99 void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 100 int mirror_num); 101 102 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 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 start_byte, 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 start_byte, 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