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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _LINUX_BLOCKGROUP_LOCK_H3#define _LINUX_BLOCKGROUP_LOCK_H4/*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_SMP14#define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32))15#else16#define NR_BG_LOCKS 117#endif18 19struct bgl_lock {20 spinlock_t lock;21} ____cacheline_aligned_in_smp;22 23struct blockgroup_lock {24 struct bgl_lock locks[NR_BG_LOCKS];25};26 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 35static inline spinlock_t *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#endif42