Btrfs: add a extent ref verify tool

index 9d89c16..71bbafe 100644
@@ -202,7 +202,7 @@ struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
  * tree until you end up with a lock on the root.  A locked buffer
  * is returned, with a reference held.
  */
-static struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root)
+struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root)
 {
 	struct extent_buffer *eb;
 

index 4253ab2..2277006 100644
@@ -1680,6 +1680,12 @@ struct btrfs_fs_info {
 
 	struct semaphore uuid_tree_rescan_sem;
 	unsigned int update_uuid_tree_gen:1;
+
+#ifdef CONFIG_BTRFS_FS_REF_VERIFY
+	spinlock_t ref_verify_lock;
+	struct rb_root block_tree;
+	bool ref_verify_enabled;
+#endif
 };
 
 struct btrfs_subvolume_writers {

@@ -3379,6 +3385,7 @@ void btrfs_set_item_key_safe(struct btrfs_root *root, struct btrfs_path *path,
 			     struct btrfs_key *new_key);
 struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root);
+struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root);
 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
 			struct btrfs_key *key, int lowest_level,
 			u64 min_trans);

index a152a96..02ae4d1 100644
@@ -49,6 +49,7 @@
 #include "dev-replace.h"
 #include "raid56.h"
 #include "sysfs.h"
+#include "ref-verify.h"
 
 #ifdef CONFIG_X86
 #include <asm/cpufeature.h>

@@ -2268,6 +2269,11 @@ int open_ctree(struct super_block *sb,
 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 	fs_info->check_integrity_print_mask = 0;
 #endif
+#ifdef CONFIG_BTRFS_FS_REF_VERIFY
+	spin_lock_init(&fs_info->ref_verify_lock);
+	fs_info->block_tree = RB_ROOT;
+	fs_info->ref_verify_enabled = true;
+#endif
 
 	spin_lock_init(&fs_info->balance_lock);
 	mutex_init(&fs_info->balance_mutex);

@@ -2895,7 +2901,12 @@ retry_root_backup:
 
 	if (sb->s_flags & MS_RDONLY)
 		return 0;
-
+#ifdef CONFIG_BTRFS_FS_REF_VERIFY
+	if (btrfs_build_ref_tree(fs_info)) {
+		fs_info->ref_verify_enabled = false;
+		printk(KERN_ERR "BTRFS: couldn't build ref tree\n");
+	}
+#endif
 	down_read(&fs_info->cleanup_work_sem);
 	if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
 	    (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {

@@ -3639,6 +3650,7 @@ int close_ctree(struct btrfs_root *root)
 	cleanup_srcu_struct(&fs_info->subvol_srcu);
 
 	btrfs_free_stripe_hash_table(fs_info);
+	btrfs_free_ref_cache(fs_info);
 
 	btrfs_free_block_rsv(root, root->orphan_block_rsv);
 	root->orphan_block_rsv = NULL;

index c69cb24..af5a656 100644
@@ -36,6 +36,7 @@
 #include "free-space-cache.h"
 #include "math.h"
 #include "sysfs.h"
+#include "ref-verify.h"
 
 #undef SCRAMBLE_DELAYED_REFS
 

@@ -1953,6 +1954,9 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
 	BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
 	       root_objectid == BTRFS_TREE_LOG_OBJECTID);
 
+	btrfs_ref_tree_mod(root, bytenr, num_bytes, parent, root_objectid,
+			   owner, offset, BTRFS_ADD_DELAYED_REF);
+
 	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
 		ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
 					num_bytes,

@@ -5955,6 +5959,9 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 	int ret;
 
 	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+		btrfs_ref_tree_mod(root, buf->start, buf->len, parent,
+				   root->objectid, btrfs_header_level(buf),
+				   0, BTRFS_DROP_DELAYED_REF);
 		ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
 					buf->start, buf->len,
 					parent, root->root_key.objectid,

@@ -6011,6 +6018,9 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 
 	add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
 
+	btrfs_ref_tree_mod(root, bytenr, num_bytes, parent, root_objectid,
+			   owner, offset, BTRFS_DROP_DELAYED_REF);
+
 	/*
 	 * tree log blocks never actually go into the extent allocation
 	 * tree, just update pinning info and exit early.

@@ -6827,6 +6837,9 @@ int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
 
 	BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
 
+	btrfs_ref_tree_mod(root, ins->objectid, ins->offset, 0, root_objectid,
+			   owner, offset, BTRFS_ADD_DELAYED_EXTENT);
+
 	ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
 					 ins->offset, 0,
 					 root_objectid, owner, offset,

@@ -7029,6 +7042,9 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
 		extent_op->is_data = 0;
 		extent_op->level = level;
 
+		btrfs_ref_tree_mod(root, ins.objectid, ins.offset, parent,
+				   root_objectid, level, 0,
+				   BTRFS_ADD_DELAYED_EXTENT);
 		ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
 					ins.objectid,
 					ins.offset, parent, root_objectid,

892 lines not on this page · raw message

new file mode 100644
index 0000000..df282ea
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2014 Facebook.  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 __REF_VERIFY__
+#define __REF_VERIFY__
+
+#ifdef CONFIG_BTRFS_FS_REF_VERIFY
+int btrfs_build_ref_tree(struct btrfs_fs_info *fs_info);
+void btrfs_free_ref_cache(struct btrfs_fs_info *fs_info);
+int btrfs_ref_tree_mod(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
+		       u64 parent, u64 ref_root, u64 owner, u64 offset,
+		       int action);
+#else
+
+#define btrfs_free_ref_cache(fs_info) do { } while (0)
+#define btrfs_ref_tree_mod(root, bytenr, num_bytes, parent, ref_root,	\
+			   owner, offset, action) do { } while (0)
+
+#endif /* CONFIG_BTRFS_FS_REF_VERIFY */
+#endif /* _REF_VERIFY__ */

index 7f92ab1..f026a82 100644
@@ -31,6 +31,7 @@
 #include "async-thread.h"
 #include "free-space-cache.h"
 #include "inode-map.h"
+#include "ref-verify.h"
 
 /*
  * backref_node, mapping_node and tree_block start with this