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 11 struct btrfs_inode; 12 13 /* 14 * We want to make sure that amount of RAM required to uncompress an extent is 15 * reasonable, so we limit the total size in ram of a compressed extent to 16 * 128k. This is a crucial number because it also controls how easily we can 17 * spread reads across cpus for decompression. 18 * 19 * We also want to make sure the amount of IO required to do a random read is 20 * reasonably small, so we limit the size of a compressed extent to 128k. 21 */ 22 23 /* Maximum length of compressed data stored on disk */ 24 #define BTRFS_MAX_COMPRESSED (SZ_128K) 25 /* Maximum size of data before compression */ 26 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K) 27 28 #define BTRFS_ZLIB_DEFAULT_LEVEL 3 29 30 struct compressed_bio { 31 /* number of bios pending for this compressed extent */ 32 refcount_t pending_bios; 33 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 /* IO errors */ 56 u8 errors; 57 int mirror_num; 58 59 /* for reads, this is the bio we are copying the data into */ 60 struct bio *orig_bio; 61 62 /* 63 * the start of a variable length array of checksums only 64 * used by reads 65 */ 66 u8 sums[]; 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 void __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, unsigned char *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, unsigned long buf_start, 90 unsigned long total_out, u64 disk_start, 91 struct bio *bio); 92 93 blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 94 unsigned int len, u64 disk_start, 95 unsigned int compressed_len, 96 struct page **compressed_pages, 97 unsigned int nr_pages, 98 unsigned int write_flags, 99 struct cgroup_subsys_state *blkcg_css); 100 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 101 int mirror_num, unsigned long bio_flags); 102 103 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 104 105 enum btrfs_compression_type { 106 BTRFS_COMPRESS_NONE = 0, 107 BTRFS_COMPRESS_ZLIB = 1, 108 BTRFS_COMPRESS_LZO = 2, 109 BTRFS_COMPRESS_ZSTD = 3, 110 BTRFS_NR_COMPRESS_TYPES = 4, 111 }; 112 113 struct workspace_manager { 114 struct list_head idle_ws; 115 spinlock_t ws_lock; 116 /* Number of free workspaces */ 117 int free_ws; 118 /* Total number of allocated workspaces */ 119 atomic_t total_ws; 120 /* Waiters for a free workspace */ 121 wait_queue_head_t ws_wait; 122 }; 123 124 struct list_head *btrfs_get_workspace(int type, unsigned int level); 125 void btrfs_put_workspace(int type, struct list_head *ws); 126 127 struct btrfs_compress_op { 128 struct workspace_manager *workspace_manager; 129 /* Maximum level supported by the compression algorithm */ 130 unsigned int max_level; 131 unsigned int default_level; 132 }; 133 134 /* The heuristic workspaces are managed via the 0th workspace manager */ 135 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 136 137 extern const struct btrfs_compress_op btrfs_heuristic_compress; 138 extern const struct btrfs_compress_op btrfs_zlib_compress; 139 extern const struct btrfs_compress_op btrfs_lzo_compress; 140 extern const struct btrfs_compress_op btrfs_zstd_compress; 141 142 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 143 bool btrfs_compress_is_valid_type(const char *str, size_t len); 144 145 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); 146 147 int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, 148 u64 start, struct page **pages, unsigned long *out_pages, 149 unsigned long *total_in, unsigned long *total_out); 150 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 151 int zlib_decompress(struct list_head *ws, unsigned char *data_in, 152 struct page *dest_page, unsigned long start_byte, size_t srclen, 153 size_t destlen); 154 struct list_head *zlib_alloc_workspace(unsigned int level); 155 void zlib_free_workspace(struct list_head *ws); 156 struct list_head *zlib_get_workspace(unsigned int level); 157 158 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, 159 u64 start, struct page **pages, unsigned long *out_pages, 160 unsigned long *total_in, unsigned long *total_out); 161 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 162 int lzo_decompress(struct list_head *ws, unsigned char *data_in, 163 struct page *dest_page, unsigned long start_byte, size_t srclen, 164 size_t destlen); 165 struct list_head *lzo_alloc_workspace(unsigned int level); 166 void lzo_free_workspace(struct list_head *ws); 167 168 int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, 169 u64 start, struct page **pages, unsigned long *out_pages, 170 unsigned long *total_in, unsigned long *total_out); 171 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 172 int zstd_decompress(struct list_head *ws, unsigned char *data_in, 173 struct page *dest_page, unsigned long start_byte, size_t srclen, 174 size_t destlen); 175 void zstd_init_workspace_manager(void); 176 void zstd_cleanup_workspace_manager(void); 177 struct list_head *zstd_alloc_workspace(unsigned int level); 178 void zstd_free_workspace(struct list_head *ws); 179 struct list_head *zstd_get_workspace(unsigned int level); 180 void zstd_put_workspace(struct list_head *ws); 181 182 #endif 183