fuse: Protect fi->nlookup with fi->lock

This continues previous patch and introduces the same protection for
nlookup field.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/fuse/dir.c

@@ -207,9 +207,9 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 				fuse_queue_forget(fc, forget, outarg.nodeid, 1);
 				goto invalid;
 			}
-			spin_lock(&fc->lock);
+			spin_lock(&fi->lock);
 			fi->nlookup++;
-			spin_unlock(&fc->lock);
+			spin_unlock(&fi->lock);
 		}
 		kfree(forget);
 		if (ret == -ENOMEM)

fs/fuse/inode.c

@@ -325,9 +325,9 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 	}
 
 	fi = get_fuse_inode(inode);
-	spin_lock(&fc->lock);
+	spin_lock(&fi->lock);
 	fi->nlookup++;
-	spin_unlock(&fc->lock);
+	spin_unlock(&fi->lock);
 	fuse_change_attributes(inode, attr, attr_valid, attr_version);
 
 	return inode;

fs/fuse/readdir.c

@@ -213,9 +213,9 @@ retry:
 		}
 
 		fi = get_fuse_inode(inode);
-		spin_lock(&fc->lock);
+		spin_lock(&fi->lock);
 		fi->nlookup++;
-		spin_unlock(&fc->lock);
+		spin_unlock(&fi->lock);
 
 		forget_all_cached_acls(inode);
 		fuse_change_attributes(inode, &o->attr,