вт, 6 нояб. 2018 г. в 9:41, Lu Fengqi <lufq.f...@cn.fujitsu.com>:
>
> 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>
> Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com>
> ---
> fs/btrfs/ctree.h | 7 ++
> fs/btrfs/dedupe.h | 128 ++++++++++++++++++++++++++++++++++++-
> fs/btrfs/disk-io.c | 1 +
> include/uapi/linux/btrfs.h | 34 ++++++++++
> 4 files changed, 168 insertions(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 80953528572d..910050d904ef 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -1118,6 +1118,13 @@ struct btrfs_fs_info {
> spinlock_t ref_verify_lock;
> struct rb_root block_tree;
> #endif
> +
> + /*
> + * Inband de-duplication related structures
> + */
> + unsigned long dedupe_enabled:1;
> + struct btrfs_dedupe_info *dedupe_info;
> + struct mutex dedupe_ioctl_lock;
> };
>
> static inline struct btrfs_fs_info *btrfs_sb(struct super_block *sb)
> diff --git a/fs/btrfs/dedupe.h b/fs/btrfs/dedupe.h
> index 90281a7a35a8..222ce7b4d827 100644
> --- a/fs/btrfs/dedupe.h
> +++ b/fs/btrfs/dedupe.h
> @@ -6,7 +6,131 @@
> #ifndef BTRFS_DEDUPE_H
> #define BTRFS_DEDUPE_H
>
> -/* later in-band dedupe will expand this struct */
> -struct btrfs_dedupe_hash;
> +#include <crypto/hash.h>
>
> +/* 32 bytes for SHA256 */
> +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;
> +};
> +
> +static inline int btrfs_dedupe_hash_hit(struct btrfs_dedupe_hash *hash)
> +{
> + return (hash && hash->bytenr);
> +}
> +
> +/*
> + * 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_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_fs_info *fs_info, u64 bytenr);
> #endif
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index b0ab41da91d1..d1fa9d90cc8f 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -2678,6 +2678,7 @@ 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 5ca1d21fc4a7..9cd15d2a40aa 100644
> --- a/include/uapi/linux/btrfs.h
> +++ b/include/uapi/linux/btrfs.h
> @@ -20,6 +20,7 @@
> #ifndef _UAPI_LINUX_BTRFS_H
> #define _UAPI_LINUX_BTRFS_H
> #include <linux/types.h>
> +#include <linux/sizes.h>
> #include <linux/ioctl.h>
>
> #define BTRFS_IOCTL_MAGIC 0x94
> @@ -667,6 +668,39 @@ 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 SZ_8M
> +#define BTRFS_DEDUPE_BLOCKSIZE_MIN SZ_16K
> +#define BTRFS_DEDUPE_BLOCKSIZE_DEFAULT SZ_128K
> +
> +/* 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
> --
> 2.19.1
Reviewed-by: Timofey Titovets <nefelim...@gmail.com>
Thanks.
--
Have a nice day,
Timofey.
