// 设置当前的目录
int
vfs_set_curdir(struct inode *dir) {
int ret = 0;
lock_cfs();
struct inode *old_dir;
if ((old_dir = get_cwd_nolock()) != dir) { // 得到当前的工作目录的inode
if (dir != NULL) {
uint32_t type;
if ((ret = vop_gettype(dir, &type)) != 0) {
goto out;
}
if (!S_ISDIR(type)) {
ret = -E_NOTDIR;
goto out;
}
vop_ref_inc(dir);
}
set_cwd_nolock(dir);
if (old_dir != NULL) {
vop_ref_dec(old_dir);
}
}
out:
unlock_cfs();
return ret;
}
// 得到当前的目录所对应的inode
int
vfs_get_curdir(struct inode **dir_store) {
struct inode *node;
if ((node = get_cwd_nolock()) != NULL) {
vop_ref_inc(node); // 增加对inode的ref_count计数
*dir_store = node; // 记录下这个node
return 0;
}
return -E_NOENT;
}
/*
* Get current directory as a inode.
*
* We do not synchronize current->fs_struct->pwd, because it belongs exclusively
* to its own process(or threads) with the holding lock.
*/
int
vfs_get_curdir(struct inode **dir_store) {
struct inode *node;
if ((node = get_cwd_nolock()) != NULL) {
vop_ref_inc(node);
*dir_store = node;
return 0;
}
return -E_NOENT;
}