#ifndef _LINUX_BLOCKGROUP_LOCK_H#define _LINUX_BLOCKGROUP_LOCK_H/* * Per-blockgroup locking for ext2 and ext3. * * Simple hashed spinlocking. */ #include <linux/spinlock.h>#include <linux/cache.h> #ifdef CONFIG_SMP#define NR_BG_LOCKS	(4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32))#else#define NR_BG_LOCKS	1#endif struct bgl_lock {	spinlock_t lock;} ____cacheline_aligned_in_smp; struct blockgroup_lock {	struct bgl_lock locks[NR_BG_LOCKS];}; static inline void bgl_lock_init(struct blockgroup_lock *bgl){	int i; 	for (i = 0; i < NR_BG_LOCKS; i++)		spin_lock_init(&bgl->locks[i].lock);} static inline spinlock_t *bgl_lock_ptr(struct blockgroup_lock *bgl, unsigned int block_group){	return &bgl->locks[block_group & (NR_BG_LOCKS-1)].lock;} #endif