1 #ifndef _LINUX_BLOCKGROUP_LOCK_H
2 #define _LINUX_BLOCKGROUP_LOCK_H
4 * Per-blockgroup locking for ext2 and ext3.
6 * Simple hashed spinlocking.
9 #include <linux/spinlock.h>
10 #include <linux/cache.h>
13 #define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32))
20 } ____cacheline_aligned_in_smp;
22 struct blockgroup_lock {
23 struct bgl_lock locks[NR_BG_LOCKS];
26 static inline void bgl_lock_init(struct blockgroup_lock *bgl)
30 for (i = 0; i < NR_BG_LOCKS; i++)
31 spin_lock_init(&bgl->locks[i].lock);
34 static inline spinlock_t *
35 bgl_lock_ptr(struct blockgroup_lock *bgl, unsigned int block_group)
37 return &bgl->locks[block_group & (NR_BG_LOCKS-1)].lock;