From: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>
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 <quwenruo@xxxxxxxxxxxxxx>
Signed-off-by: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>
---
fs/btrfs/ctree.h | 7 +++
fs/btrfs/dedupe.h | 149 +++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/disk-io.c | 1 +
include/uapi/linux/btrfs.h | 16 +++++
4 files changed, 173 insertions(+)
create mode 100644 fs/btrfs/dedupe.h
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 101c3cf..8f70f53d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1091,6 +1091,13 @@ struct btrfs_fs_info {
struct list_head pinned_chunks;
int creating_free_space_tree;
+
+ /*
+ * 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
new file mode 100644
index 0000000..d7b1a77
--- /dev/null
+++ b/fs/btrfs/dedupe.h
@@ -0,0 +1,149 @@
+/*
+ * 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>
+
+static int btrfs_dedupe_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_type;
+
+ 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 type);
+struct btrfs_dedupe_hash *btrfs_dedupe_alloc_hash(u16 type);
+
+/*
+ * 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, 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.
+ *
+ * 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);
+
+/*
+ * 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 1142127..dccd608 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2593,6 +2593,7 @@ 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 2bdd1e3..1279bf0 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -619,6 +619,22 @@ 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
+
+
#define BTRFS_QUOTA_CTL_ENABLE 1
#define BTRFS_QUOTA_CTL_DISABLE 2
#define BTRFS_QUOTA_CTL_RESCAN__NOTUSED 3
--
2.8.3
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
