From: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com>

Add generic function to initialize dedup info.

Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Signed-off-by: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com>
---
 fs/btrfs/Makefile |  2 +-
 fs/btrfs/dedup.c  | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/dedup.h  | 17 ++++++++--
 3 files changed, 113 insertions(+), 3 deletions(-)
 create mode 100644 fs/btrfs/dedup.c

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 128ce17..a6207ff 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -9,7 +9,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o 
root-tree.o dir-item.o \
           export.o tree-log.o free-space-cache.o zlib.o lzo.o \
           compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
           reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
-          uuid-tree.o props.o hash.o free-space-tree.o
+          uuid-tree.o props.o hash.o free-space-tree.o dedup.o
 
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
diff --git a/fs/btrfs/dedup.c b/fs/btrfs/dedup.c
new file mode 100644
index 0000000..2abe178
--- /dev/null
+++ b/fs/btrfs/dedup.c
@@ -0,0 +1,97 @@
+/*
+ * 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.
+ */
+#include "ctree.h"
+#include "dedup.h"
+#include "btrfs_inode.h"
+#include "transaction.h"
+#include "delayed-ref.h"
+
+int btrfs_dedup_enable(struct btrfs_fs_info *fs_info, u16 type, u16 backend,
+                      u64 blocksize, u64 limit_nr)
+{
+       struct btrfs_dedup_info *dedup_info;
+       u64 limit = limit_nr;
+       int ret = 0;
+
+       /* Sanity check */
+       if (blocksize > BTRFS_DEDUP_BLOCKSIZE_MAX ||
+           blocksize < BTRFS_DEDUP_BLOCKSIZE_MIN ||
+           blocksize < fs_info->tree_root->sectorsize ||
+           !is_power_of_2(blocksize))
+               return -EINVAL;
+       if (type >= ARRAY_SIZE(btrfs_dedup_sizes))
+               return -EINVAL;
+       if (backend >= BTRFS_DEDUP_BACKEND_LAST)
+               return -EINVAL;
+
+       if (backend == BTRFS_DEDUP_BACKEND_INMEMORY && limit_nr == 0)
+               limit = 4096; /* default value */
+       if (backend == BTRFS_DEDUP_BACKEND_ONDISK && limit_nr != 0)
+               limit = 0;
+
+       dedup_info = fs_info->dedup_info;
+       if (dedup_info) {
+               /* Check if we are re-enable for different dedup config */
+               if (dedup_info->blocksize != blocksize ||
+                   dedup_info->hash_type != type ||
+                   dedup_info->backend != backend) {
+                       btrfs_dedup_disable(fs_info);
+                       goto enable;
+               }
+
+               /* On-fly limit change is OK */
+               mutex_lock(&dedup_info->lock);
+               fs_info->dedup_info->limit_nr = limit;
+               mutex_unlock(&dedup_info->lock);
+               return 0;
+       }
+
+enable:
+       dedup_info = kzalloc(sizeof(*dedup_info), GFP_NOFS);
+       if (dedup_info)
+               return -ENOMEM;
+
+       dedup_info->hash_type = type;
+       dedup_info->backend = backend;
+       dedup_info->blocksize = blocksize;
+       dedup_info->limit_nr = limit;
+
+       /* Only support SHA256 yet */
+       dedup_info->dedup_driver = crypto_alloc_shash("sha256", 0, 0);
+       if (IS_ERR(dedup_info->dedup_driver)) {
+               btrfs_err(fs_info, "failed to init sha256 driver");
+               ret = PTR_ERR(dedup_info->dedup_driver);
+               goto out;
+       }
+
+       dedup_info->hash_root = RB_ROOT;
+       dedup_info->bytenr_root = RB_ROOT;
+       dedup_info->current_nr = 0;
+       INIT_LIST_HEAD(&dedup_info->lru_list);
+       mutex_init(&dedup_info->lock);
+
+       fs_info->dedup_info = dedup_info;
+       /* We must ensure dedup_enabled is modified after dedup_info */
+       smp_wmb();
+       fs_info->dedup_enabled = 1;
+
+out:
+       if (ret < 0)
+               kfree(dedup_info);
+       return ret;
+}
diff --git a/fs/btrfs/dedup.h b/fs/btrfs/dedup.h
index 8e1ff03..83a7512 100644
--- a/fs/btrfs/dedup.h
+++ b/fs/btrfs/dedup.h
@@ -37,6 +37,9 @@
 #define BTRFS_DEDUP_BLOCKSIZE_MIN      (16 * 1024)
 #define BTRFS_DEDUP_BLOCKSIZE_DEFAULT  (128 * 1024)
 
+/* Default dedup limit on number of hash */
+#define BTRFS_DEDUP_LIMIT_NR_DEFAULT   (32 * 1024)
+
 /* Hash algorithm, only support SHA256 yet */
 #define BTRFS_DEDUP_HASH_SHA256                0
 
@@ -74,8 +77,18 @@ struct btrfs_dedup_info {
 
 struct btrfs_trans_handle;
 
-int btrfs_dedup_hash_size(u16 type);
-struct btrfs_dedup_hash *btrfs_dedup_alloc_hash(u16 type);
+static inline int btrfs_dedup_hash_size(u16 type)
+{
+       if (WARN_ON(type >= ARRAY_SIZE(btrfs_dedup_sizes)))
+               return -EINVAL;
+       return sizeof(struct btrfs_dedup_hash) + btrfs_dedup_sizes[type];
+}
+
+static inline struct btrfs_dedup_hash *btrfs_dedup_alloc_hash(u16 type)
+{
+       return kzalloc(btrfs_dedup_hash_size(type), GFP_NOFS);
+}
+
 
 /*
  * Initial inband dedup info
-- 
2.7.0



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