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 "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 is
 25 * reasonable, so we limit the total size in ram of a compressed extent to
 26 * 128k.  This is a crucial number because it also controls how easily we can
 27 * spread reads across cpus for decompression.
 28 *
 29 * We also want to make sure the amount of IO required to do a random read is
 30 * 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		3
 42
 43struct compressed_bio {
 44	/* Number of compressed pages in the array */
 45	unsigned int nr_pages;
 46
 47	/* the pages with the compressed data on them */
 48	struct page **compressed_pages;
 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
 85int __init btrfs_init_compress(void);
 86void __cold btrfs_exit_compress(void);
 87
 88int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
 89			 u64 start, struct page **pages,
 90			 unsigned long *out_pages,
 91			 unsigned long *total_in,
 92			 unsigned long *total_out);
 93int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page,
 94		     unsigned long start_byte, size_t srclen, size_t destlen);
 95int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
 96			      struct compressed_bio *cb, u32 decompressed);
 97
 98void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
 
 
 
 99				  struct page **compressed_pages,
100				  unsigned int nr_pages,
101				  blk_opf_t write_flags,
102				  bool writeback);
103void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
104
105unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
106
107struct page *btrfs_alloc_compr_page(void);
108void btrfs_free_compr_page(struct page *page);
109
110enum btrfs_compression_type {
111	BTRFS_COMPRESS_NONE  = 0,
112	BTRFS_COMPRESS_ZLIB  = 1,
113	BTRFS_COMPRESS_LZO   = 2,
114	BTRFS_COMPRESS_ZSTD  = 3,
115	BTRFS_NR_COMPRESS_TYPES = 4,
116};
117
118struct workspace_manager {
 
119	struct list_head idle_ws;
120	spinlock_t ws_lock;
121	/* Number of free workspaces */
122	int free_ws;
123	/* Total number of allocated workspaces */
124	atomic_t total_ws;
125	/* Waiters for a free workspace */
126	wait_queue_head_t ws_wait;
127};
128
129struct list_head *btrfs_get_workspace(int type, unsigned int level);
130void btrfs_put_workspace(int type, struct list_head *ws);
 
 
 
 
131
132struct btrfs_compress_op {
133	struct workspace_manager *workspace_manager;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
134	/* Maximum level supported by the compression algorithm */
135	unsigned int max_level;
136	unsigned int default_level;
137};
138
139/* The heuristic workspaces are managed via the 0th workspace manager */
140#define BTRFS_NR_WORKSPACE_MANAGERS	BTRFS_NR_COMPRESS_TYPES
141
142extern const struct btrfs_compress_op btrfs_heuristic_compress;
143extern const struct btrfs_compress_op btrfs_zlib_compress;
144extern const struct btrfs_compress_op btrfs_lzo_compress;
145extern const struct btrfs_compress_op btrfs_zstd_compress;
146
147const char* btrfs_compress_type2str(enum btrfs_compression_type type);
148bool btrfs_compress_is_valid_type(const char *str, size_t len);
149
150int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
151
152int zlib_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);
155int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
156int zlib_decompress(struct list_head *ws, const u8 *data_in,
157		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
158		size_t destlen);
159struct list_head *zlib_alloc_workspace(unsigned int level);
160void zlib_free_workspace(struct list_head *ws);
161struct list_head *zlib_get_workspace(unsigned int level);
162
163int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
164		u64 start, struct page **pages, unsigned long *out_pages,
165		unsigned long *total_in, unsigned long *total_out);
166int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
167int lzo_decompress(struct list_head *ws, const u8 *data_in,
168		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
169		size_t destlen);
170struct list_head *lzo_alloc_workspace(unsigned int level);
171void lzo_free_workspace(struct list_head *ws);
172
173int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
174		u64 start, struct page **pages, unsigned long *out_pages,
175		unsigned long *total_in, unsigned long *total_out);
176int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
177int zstd_decompress(struct list_head *ws, const u8 *data_in,
178		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
179		size_t destlen);
180void zstd_init_workspace_manager(void);
181void zstd_cleanup_workspace_manager(void);
182struct list_head *zstd_alloc_workspace(unsigned int level);
183void zstd_free_workspace(struct list_head *ws);
184struct list_head *zstd_get_workspace(unsigned int level);
185void zstd_put_workspace(struct list_head *ws);
186
187#endif

  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/*
 12 * We want to make sure that amount of RAM required to uncompress an extent is
 13 * reasonable, so we limit the total size in ram of a compressed extent to
 14 * 128k.  This is a crucial number because it also controls how easily we can
 15 * spread reads across cpus for decompression.
 16 *
 17 * We also want to make sure the amount of IO required to do a random read is
 18 * reasonably small, so we limit the size of a compressed extent to 128k.
 19 */
 20
 21/* Maximum length of compressed data stored on disk */
 22#define BTRFS_MAX_COMPRESSED		(SZ_128K)
 
 
 
 23/* Maximum size of data before compression */
 24#define BTRFS_MAX_UNCOMPRESSED		(SZ_128K)
 25
 26#define	BTRFS_ZLIB_DEFAULT_LEVEL		3
 27
 28struct compressed_bio {
 29	/* number of bios pending for this compressed extent */
 30	refcount_t pending_bios;
 31
 32	/* the pages with the compressed data on them */
 33	struct page **compressed_pages;
 34
 35	/* inode that owns this data */
 36	struct inode *inode;
 37
 38	/* starting offset in the inode for our pages */
 39	u64 start;
 40
 41	/* number of bytes in the inode we're working on */
 42	unsigned long len;
 43
 44	/* number of bytes on disk */
 45	unsigned long compressed_len;
 46
 47	/* the compression algorithm for this bio */
 48	int compress_type;
 49
 50	/* number of compressed pages in the array */
 51	unsigned long nr_pages;
 52
 53	/* IO errors */
 54	int errors;
 55	int mirror_num;
 56
 57	/* for reads, this is the bio we are copying the data into */
 58	struct bio *orig_bio;
 59
 60	/*
 61	 * the start of a variable length array of checksums only
 62	 * used by reads
 63	 */
 64	u8 sums[];
 65};
 66
 67static inline unsigned int btrfs_compress_type(unsigned int type_level)
 68{
 69	return (type_level & 0xF);
 70}
 71
 72static inline unsigned int btrfs_compress_level(unsigned int type_level)
 73{
 74	return ((type_level & 0xF0) >> 4);
 75}
 76
 77void __init btrfs_init_compress(void);
 78void __cold btrfs_exit_compress(void);
 79
 80int 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);
 85int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
 86		     unsigned long start_byte, size_t srclen, size_t destlen);
 87int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
 88			      unsigned long total_out, u64 disk_start,
 89			      struct bio *bio);
 90
 91blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 92				  unsigned long len, u64 disk_start,
 93				  unsigned long compressed_len,
 94				  struct page **compressed_pages,
 95				  unsigned long nr_pages,
 96				  unsigned int write_flags);
 97blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 98				 int mirror_num, unsigned long bio_flags);
 99
100unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
101
 
 
 
102enum btrfs_compression_type {
103	BTRFS_COMPRESS_NONE  = 0,
104	BTRFS_COMPRESS_ZLIB  = 1,
105	BTRFS_COMPRESS_LZO   = 2,
106	BTRFS_COMPRESS_ZSTD  = 3,
107	BTRFS_COMPRESS_TYPES = 3,
108};
109
110struct workspace_manager {
111	const struct btrfs_compress_op *ops;
112	struct list_head idle_ws;
113	spinlock_t ws_lock;
114	/* Number of free workspaces */
115	int free_ws;
116	/* Total number of allocated workspaces */
117	atomic_t total_ws;
118	/* Waiters for a free workspace */
119	wait_queue_head_t ws_wait;
120};
121
122void btrfs_init_workspace_manager(struct workspace_manager *wsm,
123				  const struct btrfs_compress_op *ops);
124struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
125				      unsigned int level);
126void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws);
127void btrfs_cleanup_workspace_manager(struct workspace_manager *wsm);
128
129struct btrfs_compress_op {
130	void (*init_workspace_manager)(void);
131
132	void (*cleanup_workspace_manager)(void);
133
134	struct list_head *(*get_workspace)(unsigned int level);
135
136	void (*put_workspace)(struct list_head *ws);
137
138	struct list_head *(*alloc_workspace)(unsigned int level);
139
140	void (*free_workspace)(struct list_head *workspace);
141
142	int (*compress_pages)(struct list_head *workspace,
143			      struct address_space *mapping,
144			      u64 start,
145			      struct page **pages,
146			      unsigned long *out_pages,
147			      unsigned long *total_in,
148			      unsigned long *total_out);
149
150	int (*decompress_bio)(struct list_head *workspace,
151				struct compressed_bio *cb);
152
153	int (*decompress)(struct list_head *workspace,
154			  unsigned char *data_in,
155			  struct page *dest_page,
156			  unsigned long start_byte,
157			  size_t srclen, size_t destlen);
158
159	/* Maximum level supported by the compression algorithm */
160	unsigned int max_level;
161	unsigned int default_level;
162};
163
164/* The heuristic workspaces are managed via the 0th workspace manager */
165#define BTRFS_NR_WORKSPACE_MANAGERS	(BTRFS_COMPRESS_TYPES + 1)
166
167extern const struct btrfs_compress_op btrfs_heuristic_compress;
168extern const struct btrfs_compress_op btrfs_zlib_compress;
169extern const struct btrfs_compress_op btrfs_lzo_compress;
170extern const struct btrfs_compress_op btrfs_zstd_compress;
171
172const char* btrfs_compress_type2str(enum btrfs_compression_type type);
173bool btrfs_compress_is_valid_type(const char *str, size_t len);
174
175unsigned int btrfs_compress_set_level(int type, unsigned level);
176
177int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
178
179#endif