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 <linux/mm.h> 11 #include <linux/list.h> 12 #include <linux/workqueue.h> 13 #include <linux/wait.h> 14 #include <linux/pagemap.h> 15 #include "bio.h" 16 #include "fs.h" 17 #include "btrfs_inode.h" 18 19 struct address_space; 20 struct inode; 21 struct btrfs_inode; 22 struct btrfs_ordered_extent; 23 24 /* 25 * We want to make sure that amount of RAM required to uncompress an extent is 26 * reasonable, so we limit the total size in ram of a compressed extent to 27 * 128k. This is a crucial number because it also controls how easily we can 28 * spread reads across cpus for decompression. 29 * 30 * We also want to make sure the amount of IO required to do a random read is 31 * reasonably small, so we limit the size of a compressed extent to 128k. 32 */ 33 34 /* Maximum length of compressed data stored on disk */ 35 #define BTRFS_MAX_COMPRESSED (SZ_128K) 36 #define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE) 37 static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0); 38 39 /* Maximum size of data before compression */ 40 #define BTRFS_MAX_UNCOMPRESSED (SZ_128K) 41 42 #define BTRFS_ZLIB_DEFAULT_LEVEL 3 43 44 struct compressed_bio { 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 /* For reads, this is the bio we are copying the data into. */ 61 struct btrfs_bio *orig_bbio; 62 63 /* Must be last. */ 64 struct btrfs_bio bbio; 65 }; 66 67 static inline struct btrfs_fs_info *cb_to_fs_info(const struct compressed_bio *cb) 68 { 69 return cb->bbio.inode->root->fs_info; 70 } 71 72 /* @range_end must be exclusive. */ 73 static inline u32 btrfs_calc_input_length(struct folio *folio, u64 range_end, u64 cur) 74 { 75 /* @cur must be inside the folio. */ 76 ASSERT(folio_pos(folio) <= cur); 77 ASSERT(cur < folio_next_pos(folio)); 78 return umin(range_end, folio_next_pos(folio)) - cur; 79 } 80 81 int btrfs_alloc_compress_wsm(struct btrfs_fs_info *fs_info); 82 void btrfs_free_compress_wsm(struct btrfs_fs_info *fs_info); 83 84 int __init btrfs_init_compress(void); 85 void __cold btrfs_exit_compress(void); 86 87 bool btrfs_compress_level_valid(unsigned int type, int level); 88 int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio, 89 unsigned long dest_pgoff, 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 struct compressed_bio *btrfs_alloc_compressed_write(struct btrfs_inode *inode, 94 u64 start, u64 len); 95 void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered, 96 struct compressed_bio *cb); 97 void btrfs_submit_compressed_read(struct btrfs_bio *bbio); 98 99 int btrfs_compress_str2level(unsigned int type, const char *str, int *level_ret); 100 101 struct folio *btrfs_alloc_compr_folio(struct btrfs_fs_info *fs_info); 102 void btrfs_free_compr_folio(struct folio *folio); 103 104 struct workspace_manager { 105 struct list_head idle_ws; 106 spinlock_t ws_lock; 107 /* Number of free workspaces */ 108 int free_ws; 109 /* Total number of allocated workspaces */ 110 atomic_t total_ws; 111 /* Waiters for a free workspace */ 112 wait_queue_head_t ws_wait; 113 }; 114 115 struct list_head *btrfs_get_workspace(struct btrfs_fs_info *fs_info, int type, int level); 116 void btrfs_put_workspace(struct btrfs_fs_info *fs_info, int type, struct list_head *ws); 117 118 struct btrfs_compress_levels { 119 /* Maximum level supported by the compression algorithm */ 120 int min_level; 121 int max_level; 122 int default_level; 123 }; 124 125 /* The heuristic workspaces are managed via the 0th workspace manager */ 126 #define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES 127 128 extern const struct btrfs_compress_levels btrfs_heuristic_compress; 129 extern const struct btrfs_compress_levels btrfs_zlib_compress; 130 extern const struct btrfs_compress_levels btrfs_lzo_compress; 131 extern const struct btrfs_compress_levels btrfs_zstd_compress; 132 133 const char* btrfs_compress_type2str(enum btrfs_compression_type type); 134 bool btrfs_compress_is_valid_type(const char *str, size_t len); 135 136 int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end); 137 138 int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start, 139 struct folio **in_folio_ret); 140 struct compressed_bio *btrfs_compress_bio(struct btrfs_inode *inode, 141 u64 start, u32 len, unsigned int type, 142 int level, blk_opf_t write_flags); 143 144 static inline void cleanup_compressed_bio(struct compressed_bio *cb) 145 { 146 struct bio *bio = &cb->bbio.bio; 147 struct folio_iter fi; 148 149 bio_for_each_folio_all(fi, bio) 150 btrfs_free_compr_folio(fi.folio); 151 bio_put(bio); 152 } 153 154 int zlib_compress_bio(struct list_head *ws, struct compressed_bio *cb); 155 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 156 int zlib_decompress(struct list_head *ws, const u8 *data_in, 157 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 158 size_t destlen); 159 struct list_head *zlib_alloc_workspace(struct btrfs_fs_info *fs_info, unsigned int level); 160 void zlib_free_workspace(struct list_head *ws); 161 struct list_head *zlib_get_workspace(struct btrfs_fs_info *fs_info, unsigned int level); 162 163 int lzo_compress_bio(struct list_head *ws, struct compressed_bio *cb); 164 int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 165 int lzo_decompress(struct list_head *ws, const u8 *data_in, 166 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 167 size_t destlen); 168 struct list_head *lzo_alloc_workspace(struct btrfs_fs_info *fs_info); 169 void lzo_free_workspace(struct list_head *ws); 170 171 int zstd_compress_bio(struct list_head *ws, struct compressed_bio *cb); 172 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb); 173 int zstd_decompress(struct list_head *ws, const u8 *data_in, 174 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 175 size_t destlen); 176 int zstd_alloc_workspace_manager(struct btrfs_fs_info *fs_info); 177 void zstd_free_workspace_manager(struct btrfs_fs_info *fs_info); 178 struct list_head *zstd_alloc_workspace(struct btrfs_fs_info *fs_info, int level); 179 void zstd_free_workspace(struct list_head *ws); 180 struct list_head *zstd_get_workspace(struct btrfs_fs_info *fs_info, int level); 181 void zstd_put_workspace(struct btrfs_fs_info *fs_info, struct list_head *ws); 182 183 #endif 184