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 outstanding bios */ 35 refcount_t pending_ios; 36 37 /* Number of compressed pages in the array */ 38 unsigned int nr_pages; 39 40 /* the pages with the compressed data on them */ 41 struct page **compressed_pages; 42 43 /* inode that owns this data */ 44 struct inode *inode; 45 46 /* starting offset in the inode for our pages */ 47 u64 start; 48 49 /* Number of bytes in the inode we're working on */ 50 unsigned int len; 51 52 /* Number of bytes on disk */ 53 unsigned int compressed_len; 54 55 /* The compression algorithm for this bio */ 56 u8 compress_type; 57 58 /* Whether this is a write for writeback. */ 59 bool writeback; 60 61 /* IO errors */ 62 blk_status_t status; 63 64 union { 65 /* For reads, this is the bio we are copying the data into */ 66 struct bio *orig_bio; 67 struct work_struct write_end_work; 68 }; 69 }; 70 71 static inline unsigned int btrfs_compress_type(unsigned int type_level) 72 { 73 return (type_level & 0xF); 74 } 75 76 static inline unsigned int btrfs_compress_level(unsigned int type_level) 77 { 78 return ((type_level & 0xF0) >> 4); 79 } 80 81 int __init btrfs_init_compress(void); 82 void __cold btrfs_exit_compress(void); 83 84 int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, 85 u64 start, struct page **pages, 86 unsigned long *out_pages, 87 unsigned long *total_in, 88 unsigned long *total_out); 89 int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, 90 unsigned long start_byte, size_t srclen, size_t destlen); 91 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 92 struct compressed_bio *cb, u32 decompressed); 93 94 blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 95 unsigned int len, u64 disk_start, 96 unsigned int compressed_len, 97 struct page **compressed_pages, 98 unsigned int nr_pages, 99 blk_opf_t write_flags, 100 struct cgroup_subsys_state *blkcg_css, 101 bool writeback); 102 void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 103 int mirror_num); 104 105 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 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 inode *inode, u64 start, u64 end); 148 149 int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, 150 u64 start, struct page **pages, unsigned long *out_pages, 151 unsigned long *total_in, unsigned long *total_out); 152 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 153 int zlib_decompress(struct list_head *ws, const u8 *data_in, 154 struct page *dest_page, unsigned long start_byte, size_t srclen, 155 size_t destlen); 156 struct list_head *zlib_alloc_workspace(unsigned int level); 157 void zlib_free_workspace(struct list_head *ws); 158 struct list_head *zlib_get_workspace(unsigned int level); 159 160 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, 161 u64 start, struct page **pages, unsigned long *out_pages, 162 unsigned long *total_in, unsigned long *total_out); 163 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 164 int lzo_decompress(struct list_head *ws, const u8 *data_in, 165 struct page *dest_page, unsigned long start_byte, size_t srclen, 166 size_t destlen); 167 struct list_head *lzo_alloc_workspace(unsigned int level); 168 void lzo_free_workspace(struct list_head *ws); 169 170 int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, 171 u64 start, struct page **pages, unsigned long *out_pages, 172 unsigned long *total_in, unsigned long *total_out); 173 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 174 int zstd_decompress(struct list_head *ws, const u8 *data_in, 175 struct page *dest_page, unsigned long start_byte, size_t srclen, 176 size_t destlen); 177 void zstd_init_workspace_manager(void); 178 void zstd_cleanup_workspace_manager(void); 179 struct list_head *zstd_alloc_workspace(unsigned int level); 180 void zstd_free_workspace(struct list_head *ws); 181 struct list_head *zstd_get_workspace(unsigned int level); 182 void zstd_put_workspace(struct list_head *ws); 183 184 #endif 185