xref: /openbmc/linux/fs/btrfs/locking.h (revision f9834f18)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2008 Oracle.  All rights reserved.
4  */
5 
6 #ifndef BTRFS_LOCKING_H
7 #define BTRFS_LOCKING_H
8 
9 #include "extent_io.h"
10 
11 #define BTRFS_WRITE_LOCK 1
12 #define BTRFS_READ_LOCK 2
13 #define BTRFS_WRITE_LOCK_BLOCKING 3
14 #define BTRFS_READ_LOCK_BLOCKING 4
15 
16 void btrfs_tree_lock(struct extent_buffer *eb);
17 void btrfs_tree_unlock(struct extent_buffer *eb);
18 
19 void btrfs_tree_read_lock(struct extent_buffer *eb);
20 void btrfs_tree_read_unlock(struct extent_buffer *eb);
21 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
22 void btrfs_set_lock_blocking_read(struct extent_buffer *eb);
23 void btrfs_set_lock_blocking_write(struct extent_buffer *eb);
24 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
25 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
26 int btrfs_tree_read_lock_atomic(struct extent_buffer *eb);
27 
28 #ifdef CONFIG_BTRFS_DEBUG
29 static inline void btrfs_assert_tree_locked(struct extent_buffer *eb) {
30 	BUG_ON(!eb->write_locks);
31 }
32 #else
33 static inline void btrfs_assert_tree_locked(struct extent_buffer *eb) { }
34 #endif
35 
36 void btrfs_set_path_blocking(struct btrfs_path *p);
37 void btrfs_unlock_up_safe(struct btrfs_path *path, int level);
38 
39 static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
40 {
41 	if (rw == BTRFS_WRITE_LOCK || rw == BTRFS_WRITE_LOCK_BLOCKING)
42 		btrfs_tree_unlock(eb);
43 	else if (rw == BTRFS_READ_LOCK_BLOCKING)
44 		btrfs_tree_read_unlock_blocking(eb);
45 	else if (rw == BTRFS_READ_LOCK)
46 		btrfs_tree_read_unlock(eb);
47 	else
48 		BUG();
49 }
50 
51 #endif
52