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 11struct 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 30struct compressed_bio { 31 /* number of bios pending for this compressed extent */ 32 refcount_t pending_bios; 33 34 /* the pages with the compressed data on them */ 35 struct page **compressed_pages; 36 37 /* inode that owns this data */ 38 struct inode *inode; 39 40 /* starting offset in the inode for our pages */ 41 u64 start; 42 43 /* number of bytes in the inode we're working on */ 44 unsigned long len; 45 46 /* number of bytes on disk */ 47 unsigned long compressed_len; 48 49 /* the compression algorithm for this bio */ 50 int compress_type; 51 52 /* number of compressed pages in the array */ 53 unsigned long nr_pages; 54 55 /* IO errors */ 56 int 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 69static inline unsigned int btrfs_compress_type(unsigned int type_level) 70{ 71 return (type_level & 0xF); 72} 73 74static inline unsigned int btrfs_compress_level(unsigned int type_level) 75{ 76 return ((type_level & 0xF0) >> 4); 77} 78 79void __init btrfs_init_compress(void); 80void __cold btrfs_exit_compress(void); 81 82int 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); 87int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, 88 unsigned long start_byte, size_t srclen, size_t destlen); 89int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, 90 unsigned long total_out, u64 disk_start, 91 struct bio *bio); 92 93blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, 94 unsigned long len, u64 disk_start, 95 unsigned long compressed_len, 96 struct page **compressed_pages, 97 unsigned long nr_pages, 98 unsigned int write_flags, 99 struct cgroup_subsys_state *blkcg_css); 100blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 101 int mirror_num, unsigned long bio_flags); 102 103unsigned int btrfs_compress_str2level(unsigned int type, const char *str); 104 105enum 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 113struct 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 124struct list_head *btrfs_get_workspace(int type, unsigned int level); 125void btrfs_put_workspace(int type, struct list_head *ws); 126 127struct 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 137extern const struct btrfs_compress_op btrfs_heuristic_compress; 138extern const struct btrfs_compress_op btrfs_zlib_compress; 139extern const struct btrfs_compress_op btrfs_lzo_compress; 140extern const struct btrfs_compress_op btrfs_zstd_compress; 141 142const char* btrfs_compress_type2str(enum btrfs_compression_type type); 143bool btrfs_compress_is_valid_type(const char *str, size_t len); 144 145int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end); 146 147int 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); 150int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 151int 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); 154struct list_head *zlib_alloc_workspace(unsigned int level); 155void zlib_free_workspace(struct list_head *ws); 156struct list_head *zlib_get_workspace(unsigned int level); 157 158int 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); 161int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 162int 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); 165struct list_head *lzo_alloc_workspace(unsigned int level); 166void lzo_free_workspace(struct list_head *ws); 167 168int 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); 171int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 172int 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); 175void zstd_init_workspace_manager(void); 176void zstd_cleanup_workspace_manager(void); 177struct list_head *zstd_alloc_workspace(unsigned int level); 178void zstd_free_workspace(struct list_head *ws); 179struct list_head *zstd_get_workspace(unsigned int level); 180void zstd_put_workspace(struct list_head *ws); 181 182#endif 183