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/* SPDX-License-Identifier: GPL-2.0 */
#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
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