1 | /* SPDX-License-Identifier: GPL-2.0 */ |
---|---|
2 | #ifndef _LINUX_BLOCKGROUP_LOCK_H |
3 | #define _LINUX_BLOCKGROUP_LOCK_H |
4 | /* |
5 | * Per-blockgroup locking for ext2 and ext3. |
6 | * |
7 | * Simple hashed spinlocking. |
8 | */ |
9 | |
10 | #include <linux/spinlock.h> |
11 | #include <linux/cache.h> |
12 | |
13 | #ifdef CONFIG_SMP |
14 | #define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32)) |
15 | #else |
16 | #define NR_BG_LOCKS 1 |
17 | #endif |
18 | |
19 | struct bgl_lock { |
20 | spinlock_t lock; |
21 | } ____cacheline_aligned_in_smp; |
22 | |
23 | struct blockgroup_lock { |
24 | struct bgl_lock locks[NR_BG_LOCKS]; |
25 | }; |
26 | |
27 | static inline void bgl_lock_init(struct blockgroup_lock *bgl) |
28 | { |
29 | int i; |
30 | |
31 | for (i = 0; i < NR_BG_LOCKS; i++) |
32 | spin_lock_init(&bgl->locks[i].lock); |
33 | } |
34 | |
35 | static inline spinlock_t * |
36 | bgl_lock_ptr(struct blockgroup_lock *bgl, unsigned int block_group) |
37 | { |
38 | return &bgl->locks[block_group & (NR_BG_LOCKS-1)].lock; |
39 | } |
40 | |
41 | #endif |
42 |