1. 根目录:
2. fs
3. btrfs
4. qgroup.h

/*
 * 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 __BTRFS_QGROUP__
#define __BTRFS_QGROUP__

/*
 * A description of the operations, all of these operations only happen when we
 * are adding the 1st reference for that subvolume in the case of adding space
 * or on the last reference delete in the case of subtraction.  The only
 * exception is the last one, which is added for confusion.
 *
 * BTRFS_QGROUP_OPER_ADD_EXCL: adding bytes where this subvolume is the only
 * one pointing at the bytes we are adding.  This is called on the first
 * allocation.
 *
 * BTRFS_QGROUP_OPER_ADD_SHARED: adding bytes where this bytenr is going to be
 * shared between subvols.  This is called on the creation of a ref that already
 * has refs from a different subvolume, so basically reflink.
 *
 * BTRFS_QGROUP_OPER_SUB_EXCL: removing bytes where this subvolume is the only
 * one referencing the range.
 *
 * BTRFS_QGROUP_OPER_SUB_SHARED: removing bytes where this subvolume shares with
 * refs with other subvolumes.
 */
enum btrfs_qgroup_operation_type {
	BTRFS_QGROUP_OPER_ADD_EXCL,
	BTRFS_QGROUP_OPER_ADD_SHARED,
	BTRFS_QGROUP_OPER_SUB_EXCL,
	BTRFS_QGROUP_OPER_SUB_SHARED,
	BTRFS_QGROUP_OPER_SUB_SUBTREE,
};

struct btrfs_qgroup_operation {
	u64 ref_root;
	u64 bytenr;
	u64 num_bytes;
	u64 seq;
	enum btrfs_qgroup_operation_type type;
	struct seq_list elem;
	struct rb_node n;
	struct list_head list;
};

int btrfs_quota_enable(struct btrfs_trans_handle *trans,
		       struct btrfs_fs_info *fs_info);
int btrfs_quota_disable(struct btrfs_trans_handle *trans,
			struct btrfs_fs_info *fs_info);
int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info);
int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
			struct btrfs_fs_info *fs_info, u64 qgroupid);
int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
			      struct btrfs_fs_info *fs_info, u64 qgroupid);
int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
		       struct btrfs_fs_info *fs_info, u64 qgroupid,
		       struct btrfs_qgroup_limit *limit);
int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
struct btrfs_delayed_extent_op;
int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
			    struct btrfs_fs_info *fs_info, u64 ref_root,
			    u64 bytenr, u64 num_bytes,
			    enum btrfs_qgroup_operation_type type,
			    int mod_seq);
int btrfs_delayed_qgroup_accounting(struct btrfs_trans_handle *trans,
				    struct btrfs_fs_info *fs_info);
void btrfs_remove_qgroup_operation(struct btrfs_trans_handle *trans,
				   struct btrfs_fs_info *fs_info,
				   struct btrfs_qgroup_operation *oper);
int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
		      struct btrfs_fs_info *fs_info);
int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
			 struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
			 struct btrfs_qgroup_inherit *inherit);
int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes);
void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes);

void assert_qgroups_uptodate(struct btrfs_trans_handle *trans);

#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
			       u64 rfer, u64 excl);
#endif

#endif /* __BTRFS_QGROUP__ */