[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / compression.h

/*
 * Copyright (C) 2008 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS_COMPRESSION_
#define __BTRFS_COMPRESSION_

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

#define	BTRFS_ZLIB_DEFAULT_LEVEL		3

struct compressed_bio {
	/* number of bios pending for this compressed extent */
	refcount_t pending_bios;

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

	/* inode that owns this data */
	struct inode *inode;

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

	/* number of bytes in the inode we're working on */
	unsigned long len;

	/* number of bytes on disk */
	unsigned long compressed_len;

	/* the compression algorithm for this bio */
	int compress_type;

	/* number of compressed pages in the array */
	unsigned long nr_pages;

	/* IO errors */
	int errors;
	int mirror_num;

	/* for reads, this is the bio we are copying the data into */
	struct bio *orig_bio;

	/*
	 * the start of a variable length array of checksums only
	 * used by reads
	 */
	u32 sums;
};

void btrfs_init_compress(void);
void 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, unsigned char *data_in, struct page *dest_page,
		     unsigned long start_byte, size_t srclen, size_t destlen);
int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
			      unsigned long total_out, u64 disk_start,
			      struct bio *bio);

blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
				  unsigned long len, u64 disk_start,
				  unsigned long compressed_len,
				  struct page **compressed_pages,
				  unsigned long nr_pages,
				  unsigned int write_flags);
blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
				 int mirror_num, unsigned long bio_flags);

unsigned btrfs_compress_str2level(const char *str);

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

struct btrfs_compress_op {
	struct list_head *(*alloc_workspace)(void);

	void (*free_workspace)(struct list_head *workspace);

	int (*compress_pages)(struct list_head *workspace,
			      struct address_space *mapping,
			      u64 start,
			      struct page **pages,
			      unsigned long *out_pages,
			      unsigned long *total_in,
			      unsigned long *total_out);

	int (*decompress_bio)(struct list_head *workspace,
				struct compressed_bio *cb);

	int (*decompress)(struct list_head *workspace,
			  unsigned char *data_in,
			  struct page *dest_page,
			  unsigned long start_byte,
			  size_t srclen, size_t destlen);

	void (*set_level)(struct list_head *ws, unsigned int type);
};

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);

#endif
Commit	Line	Data
c8b97818 CM	1	/*
	2	* Copyright (C) 2008 Oracle. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18
	19	#ifndef __BTRFS_COMPRESSION_
	20	#define __BTRFS_COMPRESSION_
	21
ff763866 DS	22	/*
	23	* We want to make sure that amount of RAM required to uncompress an extent is
	24	* reasonable, so we limit the total size in ram of a compressed extent to
	25	* 128k. This is a crucial number because it also controls how easily we can
	26	* spread reads across cpus for decompression.
	27	*
	28	* We also want to make sure the amount of IO required to do a random read is
	29	* reasonably small, so we limit the size of a compressed extent to 128k.
	30	*/
	31
	32	/* Maximum length of compressed data stored on disk */
	33	#define BTRFS_MAX_COMPRESSED (SZ_128K)
	34	/* Maximum size of data before compression */
	35	#define BTRFS_MAX_UNCOMPRESSED (SZ_128K)
	36
eae8d825 QW	37	#define BTRFS_ZLIB_DEFAULT_LEVEL 3
eae8d825 QW	38
e1ddce71 AJ	39	struct compressed_bio {
	40	/* number of bios pending for this compressed extent */
	41	refcount_t pending_bios;
	42
	43	/* the pages with the compressed data on them */
	44	struct page **compressed_pages;
	45
	46	/* inode that owns this data */
	47	struct inode *inode;
	48
	49	/* starting offset in the inode for our pages */
	50	u64 start;
	51
	52	/* number of bytes in the inode we're working on */
	53	unsigned long len;
	54
	55	/* number of bytes on disk */
	56	unsigned long compressed_len;
	57
	58	/* the compression algorithm for this bio */
	59	int compress_type;
	60
	61	/* number of compressed pages in the array */
	62	unsigned long nr_pages;
	63
	64	/* IO errors */
	65	int errors;
	66	int mirror_num;
	67
	68	/* for reads, this is the bio we are copying the data into */
	69	struct bio *orig_bio;
	70
	71	/*
	72	* the start of a variable length array of checksums only
	73	* used by reads
	74	*/
	75	u32 sums;
	76	};
	77
143bede5	78	void btrfs_init_compress(void);
261507a0 LZ	79	void btrfs_exit_compress(void);
261507a0 LZ	80
f51d2b59	81	int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
38c31464	82	u64 start, struct page **pages,
261507a0 LZ	83	unsigned long *out_pages,
261507a0 LZ	84	unsigned long *total_in,
e5d74902	85	unsigned long *total_out);
261507a0 LZ	86	int btrfs_decompress(int type, unsigned char data_in, struct page dest_page,
261507a0 LZ	87	unsigned long start_byte, size_t srclen, size_t destlen);
14a3357b	88	int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
3a39c18d	89	unsigned long total_out, u64 disk_start,
974b1adc	90	struct bio *bio);
261507a0	91
4e4cbee9	92	blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
c8b97818 CM	93	unsigned long len, u64 disk_start,
	94	unsigned long compressed_len,
	95	struct page **compressed_pages,
f82b7359 LB	96	unsigned long nr_pages,
f82b7359 LB	97	unsigned int write_flags);
4e4cbee9	98	blk_status_t btrfs_submit_compressed_read(struct inode inode, struct bio bio,
c8b97818	99	int mirror_num, unsigned long bio_flags);
ebb8765b	100
f51d2b59 DS	101	unsigned btrfs_compress_str2level(const char *str);
f51d2b59 DS	102
ebb8765b AJ	103	enum btrfs_compression_type {
	104	BTRFS_COMPRESS_NONE = 0,
	105	BTRFS_COMPRESS_ZLIB = 1,
	106	BTRFS_COMPRESS_LZO = 2,
5c1aab1d NT	107	BTRFS_COMPRESS_ZSTD = 3,
5c1aab1d NT	108	BTRFS_COMPRESS_TYPES = 3,
ebb8765b AJ	109	};
ebb8765b AJ	110
261507a0 LZ	111	struct btrfs_compress_op {
	112	struct list_head (alloc_workspace)(void);
	113
	114	void (free_workspace)(struct list_head workspace);
	115
	116	int (compress_pages)(struct list_head workspace,
	117	struct address_space *mapping,
38c31464	118	u64 start,
261507a0	119	struct page **pages,
261507a0 LZ	120	unsigned long *out_pages,
261507a0 LZ	121	unsigned long *total_in,
e5d74902	122	unsigned long *total_out);
261507a0	123
974b1adc	124	int (decompress_bio)(struct list_head workspace,
e1ddce71	125	struct compressed_bio *cb);
261507a0 LZ	126
	127	int (decompress)(struct list_head workspace,
	128	unsigned char *data_in,
	129	struct page *dest_page,
	130	unsigned long start_byte,
	131	size_t srclen, size_t destlen);
f51d2b59 DS	132
f51d2b59 DS	133	void (set_level)(struct list_head ws, unsigned int type);
261507a0 LZ	134	};
261507a0 LZ	135
e8c9f186 DS	136	extern const struct btrfs_compress_op btrfs_zlib_compress;
e8c9f186 DS	137	extern const struct btrfs_compress_op btrfs_lzo_compress;
5c1aab1d	138	extern const struct btrfs_compress_op btrfs_zstd_compress;
261507a0	139
7bca7bad	140	const char* btrfs_compress_type2str(enum btrfs_compression_type type);
abc6d70b	141	bool btrfs_compress_is_valid_type(const char *str, size_t len);
7bca7bad	142
c2fcdcdf TT	143	int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
c2fcdcdf TT	144
c8b97818	145	#endif