From: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com> Introduce the header for btrfs in-band(write time) de-duplication framework and needed header.
The new de-duplication framework is going to support 2 different dedupe methods and 1 dedupe hash. Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> Signed-off-by: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com> --- fs/btrfs/ctree.h | 7 +++ fs/btrfs/dedupe.h | 137 ++++++++++++++++++++++++++++++++++++++++++++- fs/btrfs/disk-io.c | 1 + include/uapi/linux/btrfs.h | 34 +++++++++++ 4 files changed, 177 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 6097bf0..e21b315 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1099,6 +1099,13 @@ struct btrfs_fs_info { /* Used to record internally whether fs has been frozen */ int fs_frozen; + + /* + * Inband de-duplication related structures + */ + unsigned long dedupe_enabled:1; + struct btrfs_dedupe_info *dedupe_info; + struct mutex dedupe_ioctl_lock; }; struct btrfs_subvolume_writers { diff --git a/fs/btrfs/dedupe.h b/fs/btrfs/dedupe.h index 83ebfe2..5ecc321 100644 --- a/fs/btrfs/dedupe.h +++ b/fs/btrfs/dedupe.h @@ -19,6 +19,139 @@ #ifndef __BTRFS_DEDUPE__ #define __BTRFS_DEDUPE__ -/* later in-band dedupe will expand this struct */ -struct btrfs_dedupe_hash; +#include <linux/btrfs.h> +#include <linux/wait.h> +#include <crypto/hash.h> + +static const int btrfs_hash_sizes[] = { 32 }; + +/* + * For caller outside of dedupe.c + * + * Different dedupe backends should have their own hash structure + */ +struct btrfs_dedupe_hash { + u64 bytenr; + u32 num_bytes; + + /* last field is a variable length array of dedupe hash */ + u8 hash[]; +}; + +struct btrfs_dedupe_info { + /* dedupe blocksize */ + u64 blocksize; + u16 backend; + u16 hash_algo; + + struct crypto_shash *dedupe_driver; + + /* + * Use mutex to portect both backends + * Even for in-memory backends, the rb-tree can be quite large, + * so mutex is better for such use case. + */ + struct mutex lock; + + /* following members are only used in in-memory backend */ + struct rb_root hash_root; + struct rb_root bytenr_root; + struct list_head lru_list; + u64 limit_nr; + u64 current_nr; +}; + +struct btrfs_trans_handle; + +static inline int btrfs_dedupe_hash_hit(struct btrfs_dedupe_hash *hash) +{ + return (hash && hash->bytenr); +} + +int btrfs_dedupe_hash_size(u16 algo); +struct btrfs_dedupe_hash *btrfs_dedupe_alloc_hash(u16 algo); + +/* + * Initial inband dedupe info + * Called at dedupe enable time. + * + * Return 0 for success + * Return <0 for any error + * (from unsupported param to tree creation error for some backends) + */ +int btrfs_dedupe_enable(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_dedupe_args *dargs); + +/* + * Disable dedupe and invalidate all its dedupe data. + * Called at dedupe disable time. + * + * Return 0 for success + * Return <0 for any error + * (tree operation error for some backends) + */ +int btrfs_dedupe_disable(struct btrfs_fs_info *fs_info); + +/* + * Get current dedupe status. + * Return 0 for success + * No possible error yet + */ +void btrfs_dedupe_status(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_dedupe_args *dargs); + +/* + * Calculate hash for dedupe. + * Caller must ensure [start, start + dedupe_bs) has valid data. + * + * Return 0 for success + * Return <0 for any error + * (error from hash codes) + */ +int btrfs_dedupe_calc_hash(struct btrfs_fs_info *fs_info, + struct inode *inode, u64 start, + struct btrfs_dedupe_hash *hash); + +/* + * Search for duplicated extents by calculated hash + * Caller must call btrfs_dedupe_calc_hash() first to get the hash. + * + * @inode: the inode for we are writing + * @file_pos: offset inside the inode + * As we will increase extent ref immediately after a hash match, + * we need @file_pos and @inode in this case. + * + * Return > 0 for a hash match, and the extent ref will be + * *INCREASED*, and hash->bytenr/num_bytes will record the existing + * extent data. + * Return 0 for a hash miss. Nothing is done + * Return <0 for any error + * (tree operation error for some backends) + */ +int btrfs_dedupe_search(struct btrfs_fs_info *fs_info, + struct inode *inode, u64 file_pos, + struct btrfs_dedupe_hash *hash); + +/* + * Add a dedupe hash into dedupe info + * Return 0 for success + * Return <0 for any error + * (tree operation error for some backends) + */ +int btrfs_dedupe_add(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, + struct btrfs_dedupe_hash *hash); + +/* + * Remove a dedupe hash from dedupe info + * Return 0 for success + * Return <0 for any error + * (tree operation error for some backends) + * + * NOTE: if hash deletion error is not handled well, it will lead + * to corrupted fs, as later dedupe write can points to non-exist or even + * wrong extent. + */ +int btrfs_dedupe_del(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, u64 bytenr); #endif diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 3a57f99..48511a4 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2659,6 +2659,7 @@ int open_ctree(struct super_block *sb, mutex_init(&fs_info->reloc_mutex); mutex_init(&fs_info->delalloc_root_mutex); mutex_init(&fs_info->cleaner_delayed_iput_mutex); + mutex_init(&fs_info->dedupe_ioctl_lock); seqlock_init(&fs_info->profiles_lock); INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index db4c253..db1596c 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -629,6 +629,40 @@ struct btrfs_ioctl_get_dev_stats { __u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX]; /* pad to 1k */ }; +/* In-band dedupe related */ +#define BTRFS_DEDUPE_BACKEND_INMEMORY 0 +#define BTRFS_DEDUPE_BACKEND_ONDISK 1 + +/* Only support inmemory yet, so count is still only 1 */ +#define BTRFS_DEDUPE_BACKEND_COUNT 1 + +/* Dedup block size limit and default value */ +#define BTRFS_DEDUPE_BLOCKSIZE_MAX (8 * 1024 * 1024) +#define BTRFS_DEDUPE_BLOCKSIZE_MIN (16 * 1024) +#define BTRFS_DEDUPE_BLOCKSIZE_DEFAULT (128 * 1024) + +/* Hash algorithm, only support SHA256 yet */ +#define BTRFS_DEDUPE_HASH_SHA256 0 + +/* + * This structure is used for dedupe enable/disable/configure + * and status ioctl. + * Reserved range should be set to 0xff. + */ +struct btrfs_ioctl_dedupe_args { + __u16 cmd; /* In: command */ + __u64 blocksize; /* In/Out: blocksize */ + __u64 limit_nr; /* In/Out: limit nr for inmem backend */ + __u64 limit_mem; /* In/Out: limit mem for inmem backend */ + __u64 current_nr; /* Out: current hash nr */ + __u16 backend; /* In/Out: current backend */ + __u16 hash_algo; /* In/Out: hash algorithm */ + u8 status; /* Out: enabled or disabled */ + u8 flags; /* In: special flags for ioctl */ + u8 __unused[472]; /* Pad to 512 bytes */ +}; + + #define BTRFS_QUOTA_CTL_ENABLE 1 #define BTRFS_QUOTA_CTL_DISABLE 2 #define BTRFS_QUOTA_CTL_RESCAN__NOTUSED 3 -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html