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 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0); 26 27 /* Maximum size of data before compression */ 28 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K) 29 30 #define BTRFS_ZLIB_DEFAULT_LEVEL 3 31 32 struct compressed_bio { 33 /* Number of outstanding bios */ 34 refcount_t pending_ios; 35 36 /* Number of compressed pages in the array */ 37 unsigned int nr_pages; 38 39 /* the pages with the compressed data on them */ 40 struct page **compressed_pages; 41 42 /* inode that owns this data */ 43 struct inode *inode; 44 45 /* starting offset in the inode for our pages */ 46 u64 start; 47 48 /* Number of bytes in the inode we're working on */ 49 unsigned int len; 50 51 /* Number of bytes on disk */ 52 unsigned int compressed_len; 53 54 /* The compression algorithm for this bio */ 55 u8 compress_type; 56 57 /* Whether this is a write for writeback. */ 58 bool writeback; 59 60 /* IO errors */ 61 blk_status_t status; 62 63 union { 64 /* For reads, this is the bio we are copying the data into */ 65 struct bio *orig_bio; 66 struct work_struct write_end_work; 67 }; 68 }; 69 70 static inline unsigned int btrfs_compress_type(unsigned int type_level) 71 { 72 return (type_level & 0xF); 73 } 74 75 static inline unsigned int btrfs_compress_level(unsigned int type_level) 76 { 77 return ((type_level & 0xF0) >> 4); 78 } 79 80 void __init btrfs_init_compress(void); 81 void __cold btrfs_exit_compress(void); 82 83 int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, 84 u64 start, struct page **pages, 85 unsigned long *out_pages, 86 unsigned long *total_in, 87 unsigned long *total_out); 88 int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, 89 unsigned long start_byte, size_t srclen, size_t destlen); 90 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 91 struct compressed_bio *cb, u32 decompressed); 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 blk_opf_t write_flags, 99 struct cgroup_subsys_state *blkcg_css, 100 bool writeback); 101 void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 102 int mirror_num); 103 104 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 105 106 enum btrfs_compression_type { 107 BTRFS_COMPRESS_NONE = 0, 108 BTRFS_COMPRESS_ZLIB = 1, 109 BTRFS_COMPRESS_LZO = 2, 110 BTRFS_COMPRESS_ZSTD = 3, 111 BTRFS_NR_COMPRESS_TYPES = 4, 112 }; 113 114 struct workspace_manager { 115 struct list_head idle_ws; 116 spinlock_t ws_lock; 117 /* Number of free workspaces */ 118 int free_ws; 119 /* Total number of allocated workspaces */ 120 atomic_t total_ws; 121 /* Waiters for a free workspace */ 122 wait_queue_head_t ws_wait; 123 }; 124 125 struct list_head *btrfs_get_workspace(int type, unsigned int level); 126 void btrfs_put_workspace(int type, struct list_head *ws); 127 128 struct btrfs_compress_op { 129 struct workspace_manager *workspace_manager; 130 /* Maximum level supported by the compression algorithm */ 131 unsigned int max_level; 132 unsigned int default_level; 133 }; 134 135 /* The heuristic workspaces are managed via the 0th workspace manager */ 136 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 137 138 extern const struct btrfs_compress_op btrfs_heuristic_compress; 139 extern const struct btrfs_compress_op btrfs_zlib_compress; 140 extern const struct btrfs_compress_op btrfs_lzo_compress; 141 extern const struct btrfs_compress_op btrfs_zstd_compress; 142 143 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 144 bool btrfs_compress_is_valid_type(const char *str, size_t len); 145 146 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); 147 148 int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, 149 u64 start, struct page **pages, unsigned long *out_pages, 150 unsigned long *total_in, unsigned long *total_out); 151 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 152 int zlib_decompress(struct list_head *ws, unsigned char *data_in, 153 struct page *dest_page, unsigned long start_byte, size_t srclen, 154 size_t destlen); 155 struct list_head *zlib_alloc_workspace(unsigned int level); 156 void zlib_free_workspace(struct list_head *ws); 157 struct list_head *zlib_get_workspace(unsigned int level); 158 159 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, 160 u64 start, struct page **pages, unsigned long *out_pages, 161 unsigned long *total_in, unsigned long *total_out); 162 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 163 int lzo_decompress(struct list_head *ws, unsigned char *data_in, 164 struct page *dest_page, unsigned long start_byte, size_t srclen, 165 size_t destlen); 166 struct list_head *lzo_alloc_workspace(unsigned int level); 167 void lzo_free_workspace(struct list_head *ws); 168 169 int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, 170 u64 start, struct page **pages, unsigned long *out_pages, 171 unsigned long *total_in, unsigned long *total_out); 172 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 173 int zstd_decompress(struct list_head *ws, unsigned char *data_in, 174 struct page *dest_page, unsigned long start_byte, size_t srclen, 175 size_t destlen); 176 void zstd_init_workspace_manager(void); 177 void zstd_cleanup_workspace_manager(void); 178 struct list_head *zstd_alloc_workspace(unsigned int level); 179 void zstd_free_workspace(struct list_head *ws); 180 struct list_head *zstd_get_workspace(unsigned int level); 181 void zstd_put_workspace(struct list_head *ws); 182 183 #endif 184