1 /*
2  * Copyright (C) 2008 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #ifndef __BTRFS_LOCKING_
20 #define __BTRFS_LOCKING_
21 
22 #define BTRFS_WRITE_LOCK 1
23 #define BTRFS_READ_LOCK 2
24 #define BTRFS_WRITE_LOCK_BLOCKING 3
25 #define BTRFS_READ_LOCK_BLOCKING 4
26 
27 void btrfs_tree_lock(struct extent_buffer *eb);
28 void btrfs_tree_unlock(struct extent_buffer *eb);
29 int btrfs_try_spin_lock(struct extent_buffer *eb);
30 
31 void btrfs_tree_read_lock(struct extent_buffer *eb);
32 void btrfs_tree_read_unlock(struct extent_buffer *eb);
33 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
34 void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw);
35 void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
36 void btrfs_assert_tree_locked(struct extent_buffer *eb);
37 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
38 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
39 
btrfs_tree_unlock_rw(struct extent_buffer * eb,int rw)40 static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
41 {
42 	if (rw == BTRFS_WRITE_LOCK || rw == BTRFS_WRITE_LOCK_BLOCKING)
43 		btrfs_tree_unlock(eb);
44 	else if (rw == BTRFS_READ_LOCK_BLOCKING)
45 		btrfs_tree_read_unlock_blocking(eb);
46 	else if (rw == BTRFS_READ_LOCK)
47 		btrfs_tree_read_unlock(eb);
48 	else
49 		BUG();
50 }
51 
btrfs_set_lock_blocking(struct extent_buffer * eb)52 static inline void btrfs_set_lock_blocking(struct extent_buffer *eb)
53 {
54 	btrfs_set_lock_blocking_rw(eb, BTRFS_WRITE_LOCK);
55 }
56 
btrfs_clear_lock_blocking(struct extent_buffer * eb)57 static inline void btrfs_clear_lock_blocking(struct extent_buffer *eb)
58 {
59 	btrfs_clear_lock_blocking_rw(eb, BTRFS_WRITE_LOCK_BLOCKING);
60 }
61 #endif
62