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 compressed_bio { 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 /* starting offset in the inode for our pages */ 43 u64 start; 44 45 /* Number of bytes in the inode we're working on */ 46 unsigned int len; 47 48 /* Number of bytes on disk */ 49 unsigned int compressed_len; 50 51 /* The compression algorithm for this bio */ 52 u8 compress_type; 53 54 /* Whether this is a write for writeback. */ 55 bool writeback; 56 57 union { 58 /* For reads, this is the bio we are copying the data into */ 59 struct btrfs_bio *orig_bbio; 60 struct work_struct write_end_work; 61 }; 62 63 /* Must be last. */ 64 struct btrfs_bio bbio; 65 }; 66 67 static inline unsigned int btrfs_compress_type(unsigned int type_level) 68 { 69 return (type_level & 0xF); 70 } 71 72 static inline unsigned int btrfs_compress_level(unsigned int type_level) 73 { 74 return ((type_level & 0xF0) >> 4); 75 } 76 77 int __init btrfs_init_compress(void); 78 void __cold btrfs_exit_compress(void); 79 80 int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, 81 u64 start, struct page **pages, 82 unsigned long *out_pages, 83 unsigned long *total_in, 84 unsigned long *total_out); 85 int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, 86 unsigned long start_byte, size_t srclen, size_t destlen); 87 int btrfs_decompress_buf2page(const char *buf, u32 buf_len, 88 struct compressed_bio *cb, u32 decompressed); 89 90 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, 91 struct page **compressed_pages, 92 unsigned int nr_pages, 93 blk_opf_t write_flags, 94 bool writeback); 95 void btrfs_submit_compressed_read(struct btrfs_bio *bbio); 96 97 unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 98 99 enum btrfs_compression_type { 100 BTRFS_COMPRESS_NONE = 0, 101 BTRFS_COMPRESS_ZLIB = 1, 102 BTRFS_COMPRESS_LZO = 2, 103 BTRFS_COMPRESS_ZSTD = 3, 104 BTRFS_NR_COMPRESS_TYPES = 4, 105 }; 106 107 struct workspace_manager { 108 struct list_head idle_ws; 109 spinlock_t ws_lock; 110 /* Number of free workspaces */ 111 int free_ws; 112 /* Total number of allocated workspaces */ 113 atomic_t total_ws; 114 /* Waiters for a free workspace */ 115 wait_queue_head_t ws_wait; 116 }; 117 118 struct list_head *btrfs_get_workspace(int type, unsigned int level); 119 void btrfs_put_workspace(int type, struct list_head *ws); 120 121 struct btrfs_compress_op { 122 struct workspace_manager *workspace_manager; 123 /* Maximum level supported by the compression algorithm */ 124 unsigned int max_level; 125 unsigned int default_level; 126 }; 127 128 /* The heuristic workspaces are managed via the 0th workspace manager */ 129 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 130 131 extern const struct btrfs_compress_op btrfs_heuristic_compress; 132 extern const struct btrfs_compress_op btrfs_zlib_compress; 133 extern const struct btrfs_compress_op btrfs_lzo_compress; 134 extern const struct btrfs_compress_op btrfs_zstd_compress; 135 136 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 137 bool btrfs_compress_is_valid_type(const char *str, size_t len); 138 139 int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); 140 141 int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, 142 u64 start, struct page **pages, unsigned long *out_pages, 143 unsigned long *total_in, unsigned long *total_out); 144 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 145 int zlib_decompress(struct list_head *ws, const u8 *data_in, 146 struct page *dest_page, unsigned long dest_pgoff, size_t srclen, 147 size_t destlen); 148 struct list_head *zlib_alloc_workspace(unsigned int level); 149 void zlib_free_workspace(struct list_head *ws); 150 struct list_head *zlib_get_workspace(unsigned int level); 151 152 int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, 153 u64 start, struct page **pages, unsigned long *out_pages, 154 unsigned long *total_in, unsigned long *total_out); 155 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 156 int lzo_decompress(struct list_head *ws, const u8 *data_in, 157 struct page *dest_page, unsigned long start_byte, size_t srclen, 158 size_t destlen); 159 struct list_head *lzo_alloc_workspace(unsigned int level); 160 void lzo_free_workspace(struct list_head *ws); 161 162 int zstd_compress_pages(struct list_head *ws, struct address_space *mapping, 163 u64 start, struct page **pages, unsigned long *out_pages, 164 unsigned long *total_in, unsigned long *total_out); 165 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 166 int zstd_decompress(struct list_head *ws, const u8 *data_in, 167 struct page *dest_page, unsigned long start_byte, size_t srclen, 168 size_t destlen); 169 void zstd_init_workspace_manager(void); 170 void zstd_cleanup_workspace_manager(void); 171 struct list_head *zstd_alloc_workspace(unsigned int level); 172 void zstd_free_workspace(struct list_head *ws); 173 struct list_head *zstd_get_workspace(unsigned int level); 174 void zstd_put_workspace(struct list_head *ws); 175 176 #endif 177