1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 21da177e4SLinus Torvalds #ifndef _LINUX_BLOCKGROUP_LOCK_H 31da177e4SLinus Torvalds #define _LINUX_BLOCKGROUP_LOCK_H 41da177e4SLinus Torvalds /* 51da177e4SLinus Torvalds * Per-blockgroup locking for ext2 and ext3. 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Simple hashed spinlocking. 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 101da177e4SLinus Torvalds #include <linux/spinlock.h> 111da177e4SLinus Torvalds #include <linux/cache.h> 121da177e4SLinus Torvalds 131da177e4SLinus Torvalds #ifdef CONFIG_SMP 147c5f6b32SEric Biggers #define NR_BG_LOCKS (4 << ilog2(NR_CPUS < 32 ? NR_CPUS : 32)) 151da177e4SLinus Torvalds #else 161da177e4SLinus Torvalds #define NR_BG_LOCKS 1 177c5f6b32SEric Biggers #endif 181da177e4SLinus Torvalds 191da177e4SLinus Torvalds struct bgl_lock { 201da177e4SLinus Torvalds spinlock_t lock; 211da177e4SLinus Torvalds } ____cacheline_aligned_in_smp; 221da177e4SLinus Torvalds 231da177e4SLinus Torvalds struct blockgroup_lock { 241da177e4SLinus Torvalds struct bgl_lock locks[NR_BG_LOCKS]; 251da177e4SLinus Torvalds }; 261da177e4SLinus Torvalds bgl_lock_init(struct blockgroup_lock * bgl)271da177e4SLinus Torvaldsstatic inline void bgl_lock_init(struct blockgroup_lock *bgl) 281da177e4SLinus Torvalds { 291da177e4SLinus Torvalds int i; 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds for (i = 0; i < NR_BG_LOCKS; i++) 321da177e4SLinus Torvalds spin_lock_init(&bgl->locks[i].lock); 331da177e4SLinus Torvalds } 341da177e4SLinus Torvalds 35c644f0e4SPekka Enberg static inline spinlock_t * bgl_lock_ptr(struct blockgroup_lock * bgl,unsigned int block_group)36c644f0e4SPekka Enbergbgl_lock_ptr(struct blockgroup_lock *bgl, unsigned int block_group) 37c644f0e4SPekka Enberg { 389e5ab85dSEric Biggers return &bgl->locks[block_group & (NR_BG_LOCKS-1)].lock; 39c644f0e4SPekka Enberg } 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds #endif 42