/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2008 Oracle. All rights reserved. */ #ifndef BTRFS_COMPRESSION_H #define BTRFS_COMPRESSION_H #include 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) 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 compressed_bio { /* Number of sectors with unfinished IO (unsubmitted or unfinished) */ refcount_t pending_sectors; /* 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; /* Whether this is a write for writeback. */ bool writeback; /* IO errors */ blk_status_t status; int mirror_num; union { /* For reads, this is the bio we are copying the data into */ struct bio *orig_bio; struct work_struct write_end_work; }; /* * 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, bool writeback); void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, int mirror_num); 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