From: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com>
Introduce the header for btrfs online(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 | 5 ++
fs/btrfs/dedupe.h | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/disk-io.c | 1 +
3 files changed, 140 insertions(+)
create mode 100644 fs/btrfs/dedupe.h
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 84a6a5b..022ab61 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1860,6 +1860,11 @@ struct btrfs_fs_info {
struct list_head pinned_chunks;
int creating_free_space_tree;
+
+ /* Inband de-duplication related structures*/
+ unsigned int 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
new file mode 100644
index 0000000..40f4808
--- /dev/null
+++ b/fs/btrfs/dedupe.h
@@ -0,0 +1,134 @@
+/*
+ * 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_DEDUPE__
+#define __BTRFS_DEDUPE__
+
+#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_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
+
+static int btrfs_dedupe_sizes[] = { 32 };
+
+/*
+ * For caller outside of dedup.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_type;
+
+ struct crypto_shash *dedupe_driver;
+ struct mutex lock;
+
+ /* following members are only used in in-memory dedupe 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;
+
+static inline int btrfs_dedupe_hash_hit(struct btrfs_dedupe_hash *hash)
+{
+ return (hash && hash->bytenr);
+}
+
+int btrfs_dedupe_hash_size(u16 type);
+struct btrfs_dedupe_hash *btrfs_dedupe_alloc_hash(u16 type);
+
+/*
+ * Initial inband dedupe info
+ * Called at dedupe enable time.
+ */
+int btrfs_dedupe_enable(struct btrfs_fs_info *fs_info, u16 type, u16 backend,
+ u64 blocksize, u64 limit_nr, u64 limit_mem);
+
+/*
+ * Disable dedupe and invalidate all its dedupe data.
+ * Called at dedupe disable time.
+ */
+int btrfs_dedupe_disable(struct btrfs_fs_info *fs_info);
+
+/*
+ * Calculate hash for dedup.
+ * Caller must ensure [start, start + dedupe_bs) has valid data.
+ */
+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
+ */
+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 */
+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 */
+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 c95e3ce..3cf4c11 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2584,6 +2584,7 @@ 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);
--
2.7.4
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