[PATCH] FAT: cache lock from per sb to per inode

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/fat/cache.c

@@ -85,11 +85,10 @@ static int fat_cache_lookup(struct inode *inode, int fclus,
 {
 	static struct fat_cache nohit = { .fcluster = 0, };
 
-	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 	struct fat_cache *hit = &nohit, *p;
 	int offset = -1;
 
-	spin_lock(&sbi->cache_lock);
+	spin_lock(&MSDOS_I(inode)->cache_lru_lock);
 	debug_pr("FAT: %s, fclus %d", __FUNCTION__, fclus);
 	list_for_each_entry(p, &MSDOS_I(inode)->cache_lru, cache_list) {
 		if (p->fcluster <= fclus && hit->fcluster < p->fcluster) {
@@ -113,7 +112,7 @@ static int fat_cache_lookup(struct inode *inode, int fclus,
 		*cached_dclus = cache->dcluster + offset;
 	}
 	debug_pr("\n");
-	spin_unlock(&sbi->cache_lock);
+	spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
 
 	return offset;
 }
@@ -141,7 +140,6 @@ static struct fat_cache *fat_cache_merge(struct inode *inode,
 
 static void fat_cache_add(struct inode *inode, struct fat_cache *new)
 {
-	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
 	struct fat_cache *cache, *tmp;
 
 	debug_pr("FAT: %s: fclus %d, dclus %d, cont %d\n", __FUNCTION__,
@@ -150,15 +148,15 @@ static void fat_cache_add(struct inode *inode, struct fat_cache *new)
 	if (new->fcluster == -1) /* dummy cache */
 		return;
 
-	spin_lock(&sbi->cache_lock);
+	spin_lock(&MSDOS_I(inode)->cache_lru_lock);
 	cache = fat_cache_merge(inode, new);
 	if (cache == NULL) {
 		if (MSDOS_I(inode)->nr_caches < fat_max_cache(inode)) {
 			MSDOS_I(inode)->nr_caches++;
-			spin_unlock(&sbi->cache_lock);
+			spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
 
 			tmp = fat_cache_alloc(inode);
-			spin_lock(&sbi->cache_lock);
+			spin_lock(&MSDOS_I(inode)->cache_lru_lock);
 			cache = fat_cache_merge(inode, new);
 			if (cache != NULL) {
 				MSDOS_I(inode)->nr_caches--;
@@ -183,7 +181,7 @@ static void fat_cache_add(struct inode *inode, struct fat_cache *new)
 		       cache->fcluster, cache->dcluster, cache->nr_contig);
 	}
 	debug_pr("\n");
-	spin_unlock(&sbi->cache_lock);
+	spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
 }
 
 /*
@@ -205,9 +203,9 @@ static void __fat_cache_inval_inode(struct inode *inode)
 
 void fat_cache_inval_inode(struct inode *inode)
 {
-	spin_lock(&MSDOS_SB(inode->i_sb)->cache_lock);
+	spin_lock(&MSDOS_I(inode)->cache_lru_lock);
 	__fat_cache_inval_inode(inode);
-	spin_unlock(&MSDOS_SB(inode->i_sb)->cache_lock);
+	spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
 }
 
 int __fat_access(struct super_block *sb, int nr, int new_value)

fs/fat/inode.c

@@ -735,6 +735,7 @@ static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
 
 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 	    SLAB_CTOR_CONSTRUCTOR) {
+		spin_lock_init(&ei->cache_lru_lock);
 		ei->nr_caches = 0;
 		INIT_LIST_HEAD(&ei->cache_lru);
 		INIT_HLIST_NODE(&ei->i_fat_hash);
@@ -820,7 +821,6 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	if (error)
 		goto out_fail;
 
-	spin_lock_init(&MSDOS_SB(sb)->cache_lock);
 	/* set up enough so that it can read an inode */
 	init_MUTEX(&sbi->fat_lock);
 

include/linux/msdos_fs_i.h

@@ -8,6 +8,7 @@
  */
 
 struct msdos_inode_info {
+	spinlock_t cache_lru_lock;
 	struct list_head cache_lru;
 	int nr_caches;
 

include/linux/msdos_fs_sb.h

@@ -48,8 +48,6 @@ struct msdos_sb_info {
 	void *dir_ops;		     /* Opaque; default directory operations */
 	int dir_per_block;	     /* dir entries per block */
 	int dir_per_block_bits;	     /* log2(dir_per_block) */
-
-	spinlock_t cache_lock;
 };
 
 #endif