[v7,01/20] btrfs: dedup: Introduce dedup framework and its header

Message ID	1455774178-3595-2-git-send-email-quwenruo@cn.fujitsu.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-btrfs-owner@kernel.org> From: Qu Wenruo <quwenruo@cn.fujitsu.com> To: linux-btrfs@vger.kernel.org, clm@fb.com Cc: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Subject: [PATCH v7 01/20] btrfs: dedup: Introduce dedup framework and its header Date: Thu, 18 Feb 2016 13:42:39 +0800 Message-Id: <1455774178-3595-2-git-send-email-quwenruo@cn.fujitsu.com> In-Reply-To: <1455774178-3595-1-git-send-email-quwenruo@cn.fujitsu.com> References: <1455774178-3595-1-git-send-email-quwenruo@cn.fujitsu.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index bc6a87e..094db5c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1866,6 +1866,11 @@ struct btrfs_fs_info { struct list_head pinned_chunks; int creating_free_space_tree; + + /* Inband de-duplication related structures*/ + unsigned int dedup_enabled:1; + struct btrfs_dedup_info *dedup_info; + struct mutex dedup_ioctl_lock; }; struct btrfs_subvolume_writers { diff --git a/fs/btrfs/dedup.h b/fs/btrfs/dedup.h new file mode 100644 index 0000000..8e1ff03 --- /dev/null +++ b/fs/btrfs/dedup.h @@ -0,0 +1,127 @@ +/* + * Copyright (C) 2015 Fujitsu. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#ifndef __BTRFS_DEDUP__ +#define __BTRFS_DEDUP__ + +#include <linux/btrfs.h> +#include <linux/wait.h> +#include <crypto/hash.h> + +/* + * Dedup storage backend + * On disk is persist storage but overhead is large + * In memory is fast but will lose all its hash on umount + */ +#define BTRFS_DEDUP_BACKEND_INMEMORY 0 +#define BTRFS_DEDUP_BACKEND_ONDISK 1 +#define BTRFS_DEDUP_BACKEND_LAST 2 + +/* Dedup block size limit and default value */ +#define BTRFS_DEDUP_BLOCKSIZE_MAX (8 * 1024 * 1024) +#define BTRFS_DEDUP_BLOCKSIZE_MIN (16 * 1024) +#define BTRFS_DEDUP_BLOCKSIZE_DEFAULT (128 * 1024) + +/* Hash algorithm, only support SHA256 yet */ +#define BTRFS_DEDUP_HASH_SHA256 0 + +static int btrfs_dedup_sizes[] = { 32 }; + +/* + * For caller outside of dedup.c + * + * Different dedup backends should have their own hash structure + */ +struct btrfs_dedup_hash { + u64 bytenr; + u32 num_bytes; + + /* last field is a variable length array of dedup hash */ + u8 hash[]; +}; + +struct btrfs_dedup_info { + /* dedup blocksize */ + u64 blocksize; + u16 backend; + u16 hash_type; + + struct crypto_shash *dedup_driver; + struct mutex lock; + + /* following members are only used in in-memory dedup mode */ + 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; + +int btrfs_dedup_hash_size(u16 type); +struct btrfs_dedup_hash *btrfs_dedup_alloc_hash(u16 type); + +/* + * Initial inband dedup info + * Called at dedup enable time. + */ +int btrfs_dedup_enable(struct btrfs_fs_info *fs_info, u16 type, u16 backend, + u64 blocksize, u64 limit_nr); + +/* + * Disable dedup and invalidate all its dedup data. + * Called at dedup disable time. + */ +int btrfs_dedup_disable(struct btrfs_fs_info *fs_info); + +/* + * Calculate hash for dedup. + * Caller must ensure [start, start + dedup_bs) has valid data. + */ +int btrfs_dedup_calc_hash(struct btrfs_fs_info *fs_info, + struct inode *inode, u64 start, + struct btrfs_dedup_hash *hash); + +/* + * Search for duplicated extents by calculated hash + * Caller must call btrfs_dedup_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 + */ +int btrfs_dedup_search(struct btrfs_fs_info *fs_info, + struct inode *inode, u64 file_pos, + struct btrfs_dedup_hash *hash); + +/* Add a dedup hash into dedup info */ +int btrfs_dedup_add(struct btrfs_trans_handle *trans, + struct btrfs_fs_info *fs_info, + struct btrfs_dedup_hash *hash); + +/* Remove a dedup hash from dedup info */ +int btrfs_dedup_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 de68b8b..bbc17f2 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2582,6 +2582,7 @@ 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->dedup_ioctl_lock); seqlock_init(&fs_info->profiles_lock); INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);

[v7,01/20] btrfs: dedup: Introduce dedup framework and its header

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