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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * Copyright (C) 2008 Oracle. All rights reserved.4 */5 6#ifndef BTRFS_COMPRESSION_H7#define BTRFS_COMPRESSION_H8 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 "bio.h"15 16struct address_space;17struct page;18struct inode;19struct btrfs_inode;20struct btrfs_ordered_extent;21struct btrfs_bio;22 23/*24 * We want to make sure that amount of RAM required to uncompress an extent is25 * reasonable, so we limit the total size in ram of a compressed extent to26 * 128k. This is a crucial number because it also controls how easily we can27 * spread reads across cpus for decompression.28 *29 * We also want to make sure the amount of IO required to do a random read is30 * reasonably small, so we limit the size of a compressed extent to 128k.31 */32 33/* Maximum length of compressed data stored on disk */34#define BTRFS_MAX_COMPRESSED (SZ_128K)35#define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE)36static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);37 38/* Maximum size of data before compression */39#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)40 41#define BTRFS_ZLIB_DEFAULT_LEVEL 342 43struct compressed_bio {44 /* Number of compressed folios in the array. */45 unsigned int nr_folios;46 47 /* The folios with the compressed data on them. */48 struct folio **compressed_folios;49 50 /* starting offset in the inode for our pages */51 u64 start;52 53 /* Number of bytes in the inode we're working on */54 unsigned int len;55 56 /* Number of bytes on disk */57 unsigned int compressed_len;58 59 /* The compression algorithm for this bio */60 u8 compress_type;61 62 /* Whether this is a write for writeback. */63 bool writeback;64 65 union {66 /* For reads, this is the bio we are copying the data into */67 struct btrfs_bio *orig_bbio;68 struct work_struct write_end_work;69 };70 71 /* Must be last. */72 struct btrfs_bio bbio;73};74 75static inline unsigned int btrfs_compress_type(unsigned int type_level)76{77 return (type_level & 0xF);78}79 80static inline unsigned int btrfs_compress_level(unsigned int type_level)81{82 return ((type_level & 0xF0) >> 4);83}84 85/* @range_end must be exclusive. */86static inline u32 btrfs_calc_input_length(u64 range_end, u64 cur)87{88 u64 page_end = round_down(cur, PAGE_SIZE) + PAGE_SIZE;89 90 return min(range_end, page_end) - cur;91}92 93int __init btrfs_init_compress(void);94void __cold btrfs_exit_compress(void);95 96int btrfs_compress_folios(unsigned int type_level, struct address_space *mapping,97 u64 start, struct folio **folios, unsigned long *out_folios,98 unsigned long *total_in, unsigned long *total_out);99int btrfs_decompress(int type, const u8 *data_in, struct folio *dest_folio,100 unsigned long start_byte, size_t srclen, size_t destlen);101int btrfs_decompress_buf2page(const char *buf, u32 buf_len,102 struct compressed_bio *cb, u32 decompressed);103 104void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,105 struct folio **compressed_folios,106 unsigned int nr_folios, blk_opf_t write_flags,107 bool writeback);108void btrfs_submit_compressed_read(struct btrfs_bio *bbio);109 110unsigned int btrfs_compress_str2level(unsigned int type, const char *str);111 112struct folio *btrfs_alloc_compr_folio(void);113void btrfs_free_compr_folio(struct folio *folio);114 115enum btrfs_compression_type {116 BTRFS_COMPRESS_NONE = 0,117 BTRFS_COMPRESS_ZLIB = 1,118 BTRFS_COMPRESS_LZO = 2,119 BTRFS_COMPRESS_ZSTD = 3,120 BTRFS_NR_COMPRESS_TYPES = 4,121};122 123struct workspace_manager {124 struct list_head idle_ws;125 spinlock_t ws_lock;126 /* Number of free workspaces */127 int free_ws;128 /* Total number of allocated workspaces */129 atomic_t total_ws;130 /* Waiters for a free workspace */131 wait_queue_head_t ws_wait;132};133 134struct list_head *btrfs_get_workspace(int type, unsigned int level);135void btrfs_put_workspace(int type, struct list_head *ws);136 137struct btrfs_compress_op {138 struct workspace_manager *workspace_manager;139 /* Maximum level supported by the compression algorithm */140 unsigned int max_level;141 unsigned int default_level;142};143 144/* The heuristic workspaces are managed via the 0th workspace manager */145#define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES146 147extern const struct btrfs_compress_op btrfs_heuristic_compress;148extern const struct btrfs_compress_op btrfs_zlib_compress;149extern const struct btrfs_compress_op btrfs_lzo_compress;150extern const struct btrfs_compress_op btrfs_zstd_compress;151 152const char* btrfs_compress_type2str(enum btrfs_compression_type type);153bool btrfs_compress_is_valid_type(const char *str, size_t len);154 155int btrfs_compress_heuristic(struct btrfs_inode *inode, u64 start, u64 end);156 157int btrfs_compress_filemap_get_folio(struct address_space *mapping, u64 start,158 struct folio **in_folio_ret);159 160int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,161 u64 start, struct folio **folios, unsigned long *out_folios,162 unsigned long *total_in, unsigned long *total_out);163int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);164int zlib_decompress(struct list_head *ws, const u8 *data_in,165 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,166 size_t destlen);167struct list_head *zlib_alloc_workspace(unsigned int level);168void zlib_free_workspace(struct list_head *ws);169struct list_head *zlib_get_workspace(unsigned int level);170 171int lzo_compress_folios(struct list_head *ws, struct address_space *mapping,172 u64 start, struct folio **folios, unsigned long *out_folios,173 unsigned long *total_in, unsigned long *total_out);174int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);175int lzo_decompress(struct list_head *ws, const u8 *data_in,176 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,177 size_t destlen);178struct list_head *lzo_alloc_workspace(unsigned int level);179void lzo_free_workspace(struct list_head *ws);180 181int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,182 u64 start, struct folio **folios, unsigned long *out_folios,183 unsigned long *total_in, unsigned long *total_out);184int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);185int zstd_decompress(struct list_head *ws, const u8 *data_in,186 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,187 size_t destlen);188void zstd_init_workspace_manager(void);189void zstd_cleanup_workspace_manager(void);190struct list_head *zstd_alloc_workspace(unsigned int level);191void zstd_free_workspace(struct list_head *ws);192struct list_head *zstd_get_workspace(unsigned int level);193void zstd_put_workspace(struct list_head *ws);194 195#endif196