1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _LINUX_BLOCKGROUP_LOCK_H 3*4882a593Smuzhiyun #define _LINUX_BLOCKGROUP_LOCK_H 4*4882a593Smuzhiyun /* 5*4882a593Smuzhiyun * Per-blockgroup locking for ext2 and ext3. 6*4882a593Smuzhiyun * 7*4882a593Smuzhiyun * Simple hashed spinlocking. 8*4882a593Smuzhiyun */ 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun #include <linux/spinlock.h> 11*4882a593Smuzhiyun #include <linux/cache.h> 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun #ifdef CONFIG_SMP 14*4882a593Smuzhiyun #define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32)) 15*4882a593Smuzhiyun #else 16*4882a593Smuzhiyun #define NR_BG_LOCKS 1 17*4882a593Smuzhiyun #endif 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun struct bgl_lock { 20*4882a593Smuzhiyun spinlock_t lock; 21*4882a593Smuzhiyun } ____cacheline_aligned_in_smp; 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun struct blockgroup_lock { 24*4882a593Smuzhiyun struct bgl_lock locks[NR_BG_LOCKS]; 25*4882a593Smuzhiyun }; 26*4882a593Smuzhiyun bgl_lock_init(struct blockgroup_lock * bgl)27*4882a593Smuzhiyunstatic inline void bgl_lock_init(struct blockgroup_lock *bgl) 28*4882a593Smuzhiyun { 29*4882a593Smuzhiyun int i; 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun for (i = 0; i < NR_BG_LOCKS; i++) 32*4882a593Smuzhiyun spin_lock_init(&bgl->locks[i].lock); 33*4882a593Smuzhiyun } 34*4882a593Smuzhiyun 35*4882a593Smuzhiyun static inline spinlock_t * bgl_lock_ptr(struct blockgroup_lock * bgl,unsigned int block_group)36*4882a593Smuzhiyunbgl_lock_ptr(struct blockgroup_lock *bgl, unsigned int block_group) 37*4882a593Smuzhiyun { 38*4882a593Smuzhiyun return &bgl->locks[block_group & (NR_BG_LOCKS-1)].lock; 39*4882a593Smuzhiyun } 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun #endif 42