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 bgl_lock_init(struct blockgroup_lock * bgl)27static 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 * bgl_lock_ptr(struct blockgroup_lock * bgl,unsigned int block_group)36bgl_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