Add basic data structures and their init/free functions for later inband
dedup implment.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
fs/btrfs/Makefile | 2 +-
fs/btrfs/ctree.h | 5 ++++
fs/btrfs/dedup.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/dedup.h | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/disk-io.c | 7 +++++
5 files changed, 185 insertions(+), 1 deletion(-)
create mode 100644 fs/btrfs/dedup.c
create mode 100644 fs/btrfs/dedup.h
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 6d1d0b9..a8bd917 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
+ uuid-tree.o props.o hash.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/ctree.h b/fs/btrfs/ctree.h
index 68ffd26..7f37637 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -38,6 +38,7 @@
#include "extent_io.h"
#include "extent_map.h"
#include "async-thread.h"
+#include "dedup.h"
struct btrfs_trans_handle;
struct btrfs_transaction;
@@ -1788,6 +1789,9 @@ struct btrfs_fs_info {
* and will be latter freed. Protected by fs_info->chunk_mutex.
*/
struct list_head pinned_chunks;
+
+ /* Inband deduplication stuff */
+ struct btrfs_dedup_root *dedup_root;
};
struct btrfs_subvolume_writers {
@@ -3685,6 +3689,7 @@ static inline void free_fs_info(struct btrfs_fs_info
*fs_info)
kfree(fs_info->super_copy);
kfree(fs_info->super_for_commit);
security_free_mnt_opts(&fs_info->security_opts);
+ btrfs_free_dedup(fs_info);
kfree(fs_info);
}
diff --git a/fs/btrfs/dedup.c b/fs/btrfs/dedup.c
new file mode 100644
index 0000000..41f70f5
--- /dev/null
+++ b/fs/btrfs/dedup.c
@@ -0,0 +1,88 @@
+/*
+ * 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"
+
+/* SHA256, 256bits = 32 bytes */
+static int btrfs_dedup_sizes[] = { 0, 32 };
+
+struct kmem_cache *btrfs_dedup_hash_cachep;
+
+int btrfs_init_dedup(struct btrfs_fs_info *fs_info, u8 dedup_type)
+{
+ struct btrfs_dedup_root *dedup_root;
+ int ret = 0;
+
+ if (dedup_type > ARRAY_SIZE(btrfs_dedup_sizes)) {
+ pr_err("BTRFS: unsopported dedup");
+ return -EINVAL;
+ }
+
+ if (!dedup_type) {
+ fs_info->dedup_root = NULL;
+ return 0;
+ }
+
+ btrfs_dedup_hash_cachep = kmem_cache_create("btrfs_dedup_hash",
+ sizeof(struct btrfs_dedup_hash), 0,
+ SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+ if (!btrfs_dedup_hash_cachep) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ fs_info->dedup_root = kzalloc(sizeof(struct btrfs_dedup_root),
+ GFP_NOFS);
+ if (!fs_info->dedup_root) {
+ ret = -ENOMEM;
+ goto fail_hash_cachep;
+ }
+ dedup_root = fs_info->dedup_root;
+ dedup_root->dedup_type = dedup_type;
+
+ switch (dedup_type) {
+ case BTRFS_DEDUP_HASH_SHA256:
+ dedup_root->dedup_driver = crypto_alloc_shash("sha256", 0, 0);
+ if (IS_ERR(dedup_root->dedup_driver)) {
+ pr_err("BTRFS: Cannot load sha256 driver\n");
+ goto fail_dedup_root;
+ }
+ }
+
+ dedup_root->hash_root = RB_ROOT;
+ dedup_root->bytenr_root = RB_ROOT;
+ INIT_LIST_HEAD(&dedup_root->lru_list);
+ spin_lock_init(&dedup_root->lock);
+ return 0;
+
+fail_dedup_root:
+ kfree(dedup_root);
+fail_hash_cachep:
+ kmem_cache_destroy(btrfs_dedup_hash_cachep);
+fail:
+ return ret;
+}
+
+void btrfs_free_dedup(struct btrfs_fs_info *fs_info)
+{
+ if (!fs_info->dedup_root)
+ return;
+
+ kfree(fs_info->dedup_root);
+ return;
+}
diff --git a/fs/btrfs/dedup.h b/fs/btrfs/dedup.h
new file mode 100644
index 0000000..341ca33
--- /dev/null
+++ b/fs/btrfs/dedup.h
@@ -0,0 +1,84 @@
+/*
+ * 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 __DEDUP__
+#define __DEDUP__
+
+#include <linux/rbtree.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <crypto/hash.h>
+
+#define BTRFS_DEDUP_DISABLED 0
+#define BTRFS_DEDUP_HASH_SHA256 1
+
+/*
+ * As we need to use kmem_cache to speed the super frequent memory alloc,
+ * we can't use variable length array in btrfs_dedup_hash.
+ * So set DEDUP_HASH_SIZE to a fixed size
+ *
+ * The 32 bytes is for SHA256 so far.
+ */
+#define BTRFS_DEDUP_HASH_SIZE 32
+
+extern struct kmem_cache *btrfs_dedup_hash_cachep;
+
+struct btrfs_dedup_hash {
+ /* Hash -> extent(bytenr + offset) search, for dedup search */
+ struct rb_node hash_node;
+
+ /* Extent(bytenr + offset) -> hash search, for free extent */
+ struct rb_node bytenr_node;
+
+ /* LRU list to maintain low memory usage */
+ struct list_head lru_list;
+
+ /* The bytenr of the data extent */
+ u64 bytenr;
+
+ /* The length of the data extent */
+ u64 length;
+
+ /*
+ * The offset inside the extent
+ * TODO: Use offset to support compression
+ */
+ u32 offset;
+
+ /* fixed length for hash, it's OK not to use full of them */
+ char hash[BTRFS_DEDUP_HASH_SIZE];
+};
+
+struct btrfs_dedup_root {
+ struct rb_root hash_root;
+ struct rb_root bytenr_root;
+ struct list_head lru_list;
+
+ spinlock_t lock;
+
+ struct crypto_shash *dedup_driver;
+ u8 dedup_type;
+
+ /* To limit the amount of btrfs_dedup_hash */
+ u32 limit_nr;
+ u32 current_nr;
+};
+
+int btrfs_init_dedup(struct btrfs_fs_info *fs_info, u8 dedup_type);
+void btrfs_free_dedup(struct btrfs_fs_info *fs_info);
+#endif
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a9aadb2..3997bd9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -49,6 +49,7 @@
#include "raid56.h"
#include "sysfs.h"
#include "qgroup.h"
+#include "dedup.h"
#ifdef CONFIG_X86
#include <asm/cpufeature.h>
@@ -2633,6 +2634,12 @@ int open_ctree(struct super_block *sb,
INIT_LIST_HEAD(&fs_info->pinned_chunks);
+ /* TODO: use real dedup type other than 0 */
+ ret = btrfs_init_dedup(fs_info, 0);
+ if (ret) {
+ err = -ret;
+ goto fail_alloc;
+ }
ret = btrfs_alloc_stripe_hash_table(fs_info);
if (ret) {
err = ret;
--
2.4.6
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