[linux-2.6-block.git] / fs / btrfs / compression.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2008 Oracle.  All rights reserved.
 */

#ifndef BTRFS_COMPRESSION_H
#define BTRFS_COMPRESSION_H

#include <linux/sizes.h>
#include "bio.h"

struct btrfs_inode;
struct btrfs_ordered_extent;

/*
 * We want to make sure that amount of RAM required to uncompress an extent is
 * reasonable, so we limit the total size in ram of a compressed extent to
 * 128k.  This is a crucial number because it also controls how easily we can
 * spread reads across cpus for decompression.
 *
 * We also want to make sure the amount of IO required to do a random read is
 * reasonably small, so we limit the size of a compressed extent to 128k.
 */

/* Maximum length of compressed data stored on disk */
#define BTRFS_MAX_COMPRESSED		(SZ_128K)
#define BTRFS_MAX_COMPRESSED_PAGES	(BTRFS_MAX_COMPRESSED / PAGE_SIZE)
static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);

/* Maximum size of data before compression */
#define BTRFS_MAX_UNCOMPRESSED		(SZ_128K)

#define	BTRFS_ZLIB_DEFAULT_LEVEL		3

struct page;

struct compressed_bio {
	/* Number of compressed pages in the array */
	unsigned int nr_pages;

	/* the pages with the compressed data on them */
	struct page **compressed_pages;

	/* starting offset in the inode for our pages */
	u64 start;

	/* Number of bytes in the inode we're working on */
	unsigned int len;

	/* Number of bytes on disk */
	unsigned int compressed_len;

	/* The compression algorithm for this bio */
	u8 compress_type;

	/* Whether this is a write for writeback. */
	bool writeback;

	union {
		/* For reads, this is the bio we are copying the data into */
		struct btrfs_bio *orig_bbio;
		struct work_struct write_end_work;
	};

	/* Must be last. */
	struct btrfs_bio bbio;
};

static inline unsigned int btrfs_compress_type(unsigned int type_level)
{
	return (type_level & 0xF);
}

static inline unsigned int btrfs_compress_level(unsigned int type_level)
{
	return ((type_level & 0xF0) >> 4);
}

int __init btrfs_init_compress(void);
void __cold btrfs_exit_compress(void);

int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
			 u64 start, struct page **pages,
			 unsigned long *out_pages,
			 unsigned long *total_in,
			 unsigned long *total_out);
int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page,
		     unsigned long start_byte, size_t srclen, size_t destlen);
int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
			      struct compressed_bio *cb, u32 decompressed);

void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
				  struct page **compressed_pages,
				  unsigned int nr_pages,
				  blk_opf_t write_flags,
				  bool writeback);
void btrfs_submit_compressed_read(struct btrfs_bio *bbio);

unsigned int btrfs_compress_str2level(unsigned int type, const char *str);

struct page *btrfs_alloc_compr_page(void);
void btrfs_free_compr_page(struct page *page);

enum btrfs_compression_type {
	BTRFS_COMPRESS_NONE  = 0,
	BTRFS_COMPRESS_ZLIB  = 1,
	BTRFS_COMPRESS_LZO   = 2,
	BTRFS_COMPRESS_ZSTD  = 3,
	BTRFS_NR_COMPRESS_TYPES = 4,
};

struct workspace_manager {
	struct list_head idle_ws;
	spinlock_t ws_lock;
	/* Number of free workspaces */
	int free_ws;
	/* Total number of allocated workspaces */
	atomic_t total_ws;
	/* Waiters for a free workspace */
	wait_queue_head_t ws_wait;
};

struct list_head *btrfs_get_workspace(int type, unsigned int level);
void btrfs_put_workspace(int type, struct list_head *ws);

struct btrfs_compress_op {
	struct workspace_manager *workspace_manager;
	/* Maximum level supported by the compression algorithm */
	unsigned int max_level;
	unsigned int default_level;
};

/* The heuristic workspaces are managed via the 0th workspace manager */
#define BTRFS_NR_WORKSPACE_MANAGERS	BTRFS_NR_COMPRESS_TYPES

extern const struct btrfs_compress_op btrfs_heuristic_compress;
extern const struct btrfs_compress_op btrfs_zlib_compress;
extern const struct btrfs_compress_op btrfs_lzo_compress;
extern const struct btrfs_compress_op btrfs_zstd_compress;

const char* btrfs_compress_type2str(enum btrfs_compression_type type);
bool btrfs_compress_is_valid_type(const char *str, size_t len);

int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);

int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
		u64 start, struct page **pages, unsigned long *out_pages,
		unsigned long *total_in, unsigned long *total_out);
int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
int zlib_decompress(struct list_head *ws, const u8 *data_in,
		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
		size_t destlen);
struct list_head *zlib_alloc_workspace(unsigned int level);
void zlib_free_workspace(struct list_head *ws);
struct list_head *zlib_get_workspace(unsigned int level);

int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
		u64 start, struct page **pages, unsigned long *out_pages,
		unsigned long *total_in, unsigned long *total_out);
int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
int lzo_decompress(struct list_head *ws, const u8 *data_in,
		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
		size_t destlen);
struct list_head *lzo_alloc_workspace(unsigned int level);
void lzo_free_workspace(struct list_head *ws);

int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
		u64 start, struct page **pages, unsigned long *out_pages,
		unsigned long *total_in, unsigned long *total_out);
int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
int zstd_decompress(struct list_head *ws, const u8 *data_in,
		struct page *dest_page, unsigned long start_byte, size_t srclen,
		size_t destlen);
void zstd_init_workspace_manager(void);
void zstd_cleanup_workspace_manager(void);
struct list_head *zstd_alloc_workspace(unsigned int level);
void zstd_free_workspace(struct list_head *ws);
struct list_head *zstd_get_workspace(unsigned int level);
void zstd_put_workspace(struct list_head *ws);

#endif
Commit	Line	Data
9888c340	1	/* SPDX-License-Identifier: GPL-2.0 */
c8b97818 CM	2	/*
c8b97818 CM	3	* Copyright (C) 2008 Oracle. All rights reserved.
c8b97818 CM	4	*/
c8b97818 CM	5
9888c340 DS	6	#ifndef BTRFS_COMPRESSION_H
9888c340 DS	7	#define BTRFS_COMPRESSION_H
c8b97818	8
d5c1d68f	9	#include <linux/sizes.h>
544fe4a9	10	#include "bio.h"
d5c1d68f	11
c7ee1819	12	struct btrfs_inode;
d611935b	13	struct btrfs_ordered_extent;
c7ee1819	14
ff763866 DS	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)
544fe4a9	27	#define BTRFS_MAX_COMPRESSED_PAGES (BTRFS_MAX_COMPRESSED / PAGE_SIZE)
a55e65b8 DS	28	static_assert((BTRFS_MAX_COMPRESSED % PAGE_SIZE) == 0);
a55e65b8 DS	29
ff763866 DS	30	/* Maximum size of data before compression */
	31	#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
	32
eae8d825 QW	33	#define BTRFS_ZLIB_DEFAULT_LEVEL 3
eae8d825 QW	34
9ba965dc DS	35	struct page;
9ba965dc DS	36
e1ddce71	37	struct compressed_bio {
282ab3ff DS	38	/* Number of compressed pages in the array */
	39	unsigned int nr_pages;
	40
e1ddce71 AJ	41	/* the pages with the compressed data on them */
	42	struct page **compressed_pages;
	43
e1ddce71 AJ	44	/* starting offset in the inode for our pages */
	45	u64 start;
	46
282ab3ff DS	47	/* Number of bytes in the inode we're working on */
282ab3ff DS	48	unsigned int len;
e1ddce71	49
282ab3ff DS	50	/* Number of bytes on disk */
282ab3ff DS	51	unsigned int compressed_len;
e1ddce71	52
282ab3ff DS	53	/* The compression algorithm for this bio */
282ab3ff DS	54	u8 compress_type;
e1ddce71	55
7c0c7269 OS	56	/* Whether this is a write for writeback. */
	57	bool writeback;
	58
fed8a72d CH	59	union {
fed8a72d CH	60	/* For reads, this is the bio we are copying the data into */
b7d463a1	61	struct btrfs_bio *orig_bbio;
fed8a72d CH	62	struct work_struct write_end_work;
fed8a72d CH	63	};
544fe4a9 CH	64
	65	/* Must be last. */
	66	struct btrfs_bio bbio;
e1ddce71 AJ	67	};
e1ddce71 AJ	68
1972708a DZ	69	static inline unsigned int btrfs_compress_type(unsigned int type_level)
	70	{
	71	return (type_level & 0xF);
	72	}
	73
	74	static inline unsigned int btrfs_compress_level(unsigned int type_level)
	75	{
	76	return ((type_level & 0xF0) >> 4);
	77	}
	78
5565b8e0	79	int __init btrfs_init_compress(void);
e67c718b	80	void __cold btrfs_exit_compress(void);
261507a0	81
f51d2b59	82	int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
38c31464	83	u64 start, struct page **pages,
261507a0 LZ	84	unsigned long *out_pages,
261507a0 LZ	85	unsigned long *total_in,
e5d74902	86	unsigned long *total_out);
3e09b5b2	87	int btrfs_decompress(int type, const u8 data_in, struct page dest_page,
261507a0	88	unsigned long start_byte, size_t srclen, size_t destlen);
1c3dc173 QW	89	int btrfs_decompress_buf2page(const char *buf, u32 buf_len,
1c3dc173 QW	90	struct compressed_bio *cb, u32 decompressed);
261507a0	91
d611935b	92	void btrfs_submit_compressed_write(struct btrfs_ordered_extent *ordered,
c8b97818	93	struct page **compressed_pages,
65b5355f	94	unsigned int nr_pages,
bf9486d6	95	blk_opf_t write_flags,
7c0c7269	96	bool writeback);
e1949310	97	void btrfs_submit_compressed_read(struct btrfs_bio *bbio);
ebb8765b	98
d0ab62ce	99	unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
f51d2b59	100
9ba965dc DS	101	struct page *btrfs_alloc_compr_page(void);
	102	void btrfs_free_compr_page(struct page *page);
	103
ebb8765b AJ	104	enum btrfs_compression_type {
	105	BTRFS_COMPRESS_NONE = 0,
	106	BTRFS_COMPRESS_ZLIB = 1,
	107	BTRFS_COMPRESS_LZO = 2,
5c1aab1d	108	BTRFS_COMPRESS_ZSTD = 3,
ce96b7ff	109	BTRFS_NR_COMPRESS_TYPES = 4,
ebb8765b AJ	110	};
ebb8765b AJ	111
92ee5530	112	struct workspace_manager {
92ee5530 DZ	113	struct list_head idle_ws;
	114	spinlock_t ws_lock;
	115	/* Number of free workspaces */
	116	int free_ws;
	117	/* Total number of allocated workspaces */
	118	atomic_t total_ws;
	119	/* Waiters for a free workspace */
	120	wait_queue_head_t ws_wait;
	121	};
	122
5907a9bb	123	struct list_head *btrfs_get_workspace(int type, unsigned int level);
a3bbd2a9	124	void btrfs_put_workspace(int type, struct list_head *ws);
92ee5530	125
261507a0	126	struct btrfs_compress_op {
be951045	127	struct workspace_manager *workspace_manager;
e18333a7 DS	128	/* Maximum level supported by the compression algorithm */
	129	unsigned int max_level;
	130	unsigned int default_level;
261507a0 LZ	131	};
261507a0 LZ	132
ca4ac360	133	/* The heuristic workspaces are managed via the 0th workspace manager */
ce96b7ff	134	#define BTRFS_NR_WORKSPACE_MANAGERS BTRFS_NR_COMPRESS_TYPES
ca4ac360 DZ	135
ca4ac360 DZ	136	extern const struct btrfs_compress_op btrfs_heuristic_compress;
e8c9f186 DS	137	extern const struct btrfs_compress_op btrfs_zlib_compress;
e8c9f186 DS	138	extern const struct btrfs_compress_op btrfs_lzo_compress;
5c1aab1d	139	extern const struct btrfs_compress_op btrfs_zstd_compress;
261507a0	140
e128f9c3	141	const char* btrfs_compress_type2str(enum btrfs_compression_type type);
aa53e3bf	142	bool btrfs_compress_is_valid_type(const char *str, size_t len);
e128f9c3	143
c2fcdcdf TT	144	int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
c2fcdcdf TT	145
cb4c9198 DS	146	int zlib_compress_pages(struct list_head ws, struct address_space mapping,
	147	u64 start, struct page *pages, unsigned long out_pages,
	148	unsigned long total_in, unsigned long total_out);
	149	int zlib_decompress_bio(struct list_head ws, struct compressed_bio cb);
3e09b5b2	150	int zlib_decompress(struct list_head ws, const u8 data_in,
2c25716d	151	struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
cb4c9198 DS	152	size_t destlen);
	153	struct list_head *zlib_alloc_workspace(unsigned int level);
	154	void zlib_free_workspace(struct list_head *ws);
	155	struct list_head *zlib_get_workspace(unsigned int level);
	156
	157	int lzo_compress_pages(struct list_head ws, struct address_space mapping,
	158	u64 start, struct page *pages, unsigned long out_pages,
	159	unsigned long total_in, unsigned long total_out);
	160	int lzo_decompress_bio(struct list_head ws, struct compressed_bio cb);
3e09b5b2	161	int lzo_decompress(struct list_head ws, const u8 data_in,
6a69631e	162	struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
cb4c9198 DS	163	size_t destlen);
	164	struct list_head *lzo_alloc_workspace(unsigned int level);
	165	void lzo_free_workspace(struct list_head *ws);
	166
	167	int zstd_compress_pages(struct list_head ws, struct address_space mapping,
	168	u64 start, struct page *pages, unsigned long out_pages,
	169	unsigned long total_in, unsigned long total_out);
	170	int zstd_decompress_bio(struct list_head ws, struct compressed_bio cb);
3e09b5b2	171	int zstd_decompress(struct list_head ws, const u8 data_in,
e01a83e1	172	struct page *dest_page, unsigned long start_byte, size_t srclen,
cb4c9198 DS	173	size_t destlen);
	174	void zstd_init_workspace_manager(void);
	175	void zstd_cleanup_workspace_manager(void);
	176	struct list_head *zstd_alloc_workspace(unsigned int level);
	177	void zstd_free_workspace(struct list_head *ws);
	178	struct list_head *zstd_get_workspace(unsigned int level);
	179	void zstd_put_workspace(struct list_head *ws);
	180
c8b97818	181	#endif