kernel_optimize_test/fs/btrfs/compression.h
Chengguang Xu ce96b7ffd1 btrfs: use better definition of number of compression type
The compression type upper limit constant is the same as the last value
and this is confusing.  In order to keep coding style consistent, use
BTRFS_NR_COMPRESS_TYPES as the total number that follows the idom of
'NR' being one more than the last value.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:55 +01:00

181 lines
5.3 KiB
C

/* 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>
/*
* 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
*/
u8 sums[];
};
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);
}
void __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, 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,
struct cgroup_subsys_state *blkcg_css);
blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
int mirror_num, unsigned long bio_flags);
unsigned int btrfs_compress_str2level(unsigned int type, const char *str);
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 {
const struct btrfs_compress_op *ops;
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;
};
void btrfs_init_workspace_manager(struct workspace_manager *wsm,
const struct btrfs_compress_op *ops);
struct list_head *btrfs_get_workspace(struct workspace_manager *wsm,
unsigned int level);
void btrfs_put_workspace(struct workspace_manager *wsm, struct list_head *ws);
void btrfs_cleanup_workspace_manager(struct workspace_manager *wsm);
struct btrfs_compress_op {
void (*init_workspace_manager)(void);
void (*cleanup_workspace_manager)(void);
struct list_head *(*get_workspace)(unsigned int level);
void (*put_workspace)(struct list_head *ws);
struct list_head *(*alloc_workspace)(unsigned int level);
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);
/* 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);
unsigned int btrfs_compress_set_level(int type, unsigned level);
int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
#endif