| /* 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> |
| |
| struct btrfs_inode; |
| |
| /* |
| * 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; |
| |
| /* Number of compressed pages in the array */ |
| unsigned int nr_pages; |
| |
| /* 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 int len; |
| |
| /* Number of bytes on disk */ |
| unsigned int compressed_len; |
| |
| /* The compression algorithm for this bio */ |
| u8 compress_type; |
| |
| /* IO errors */ |
| u8 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, u32 buf_len, |
| struct compressed_bio *cb, u32 decompressed); |
| |
| blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, |
| unsigned int len, u64 disk_start, |
| unsigned int compressed_len, |
| struct page **compressed_pages, |
| unsigned int 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 { |
| 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, unsigned char *data_in, |
| struct page *dest_page, unsigned long start_byte, 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, unsigned char *data_in, |
| struct page *dest_page, unsigned long start_byte, 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, unsigned char *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 |