| 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 |