static int scfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int ret;
struct dentry *lower_dentry = scfs_lower_dentry(dentry);
ret = lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
if (ret)
return ret;
buf->f_type = SCFS_SUPER_MAGIC;
return ret;
}
static struct inode *
scfs_do_create(struct inode *parent_inode,
struct dentry *scfs_dentry, umode_t mode)
{
struct dentry *lower_file_dentry;
struct dentry *lower_parent_dentry;
struct inode *inode;
int ret;
SCFS_DEBUG_START;
lower_file_dentry = scfs_lower_dentry(scfs_dentry);
lower_parent_dentry = lock_parent(lower_file_dentry);
if (IS_ERR(lower_parent_dentry)) {
SCFS_PRINT_ERROR("lower_parent_dentry is invalid\n");
inode = ERR_CAST(lower_parent_dentry);
goto out;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
ret = vfs_create(lower_parent_dentry->d_inode, lower_file_dentry,
mode, true);
#else
ret = vfs_create(lower_parent_dentry->d_inode, lower_file_dentry,
mode, NULL);
#endif
if (ret) {
SCFS_PRINT_ERROR("error in vfs_create, lower create, ret : %d\n", ret);
inode = ERR_PTR(ret);
goto unlock;
}
inode = _scfs_get_inode(lower_file_dentry->d_inode, parent_inode->i_sb);
if (IS_ERR(inode)) {
SCFS_PRINT_ERROR("error in get_inode, so lower thing will be unlinked\n");
vfs_unlink(lower_parent_dentry->d_inode, lower_file_dentry);
goto unlock;
}
fsstack_copy_attr_times(parent_inode, lower_parent_dentry->d_inode);
fsstack_copy_inode_size(parent_inode, lower_parent_dentry->d_inode);
unlock:
unlock_dir(lower_parent_dentry);
out:
SCFS_DEBUG_END;
return inode;
}
/*
* scfs_mkdir
*
* Parameters:
* @*dir: inode of the dir to create
* @*scfs_dentry: dentry of the dir to create
* @mode:
*
* Return:
* SCFS_SUCCESS if success, otherwise if error
*
* Description:
* mkdir() for SCFS.
*/
static int scfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct dentry *lower_dir_dentry;
struct dentry *lower_parent_dentry;
int ret;
SCFS_DEBUG_START;
lower_dir_dentry = scfs_lower_dentry(dentry);
lower_parent_dentry = lock_parent(lower_dir_dentry);
ret = vfs_mkdir(lower_parent_dentry->d_inode, lower_dir_dentry, mode);
if (ret || !lower_dir_dentry->d_inode) {
SCFS_PRINT_ERROR("dir %s vfs_mkdir failed, "
"lower_dir %s lower_parent %s mode %x\n",
dentry->d_name.name,
lower_dir_dentry->d_name.name,
lower_parent_dentry->d_name.name, mode);
goto out;
}
ret = scfs_interpose(lower_dir_dentry, dentry, dir->i_sb);
if (ret) {
SCFS_PRINT_ERROR("dir %s interpose failed, "
"lower_dir %s lower_parent %s mode %x\n",
dentry->d_name.name,
lower_dir_dentry->d_name.name,
lower_parent_dentry->d_name.name, mode);
vfs_rmdir(lower_parent_dentry->d_inode, lower_dir_dentry);
goto out;
}
fsstack_copy_attr_times(dir, lower_parent_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
set_nlink(dir, lower_parent_dentry->d_inode->i_nlink);
out:
unlock_dir(lower_parent_dentry);
if (!dentry->d_inode)
d_drop(dentry);
SCFS_DEBUG_END;
return ret;
}
static int scfs_do_unlink(struct inode *dir, struct dentry *dentry, struct inode *inode)
{
struct dentry *lower_dentry = scfs_lower_dentry(dentry);
struct inode *lower_dir_inode = scfs_lower_inode(dir);
struct dentry *lower_dir_dentry;
int ret;
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
ret = vfs_unlink(lower_dir_inode, lower_dentry);
if (ret) {
SCFS_PRINT_ERROR("error in vfs_unlink, ret : %d\n", ret);
goto out;
}
fsstack_copy_attr_times(dir, lower_dir_inode);
set_nlink(inode, scfs_lower_inode(inode)->i_nlink);
inode->i_ctime = dir->i_ctime;
d_drop(dentry);
out:
unlock_dir(lower_dir_dentry);
dput(lower_dentry);
return ret;
}