Re: [f2fs-dev] [PATCH v4] f2fs: add F2FS_IOC_SEC_TRIM_FILE ioctl

[Eric Biggers]

Hi Daeho,

On Thu, Jun 18, 2020 at 09:51:52PM +0900, Daeho Jeong wrote:
> +static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)
> +{
> +	struct inode *inode = file_inode(filp);
> +	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> +	struct address_space *mapping = inode->i_mapping;
> +	struct block_device *prev_bdev = NULL;
> +	struct f2fs_sectrim_range range;
> +	pgoff_t index, pg_end;
> +	block_t prev_block = 0, len = 0;
> +	u64 end_addr;
> +	bool to_end;
> +	int ret = 0;
> +
> +	if (!(filp->f_mode & FMODE_WRITE))
> +		return -EBADF;
> +
> +	if (copy_from_user(&range, (struct f2fs_sectrim_range __user *)arg,
> +				sizeof(range)))
> +		return -EFAULT;
> +
> +	if (range.flags == 0 || (range.flags & ~F2FS_TRIM_FILE_MASK) ||
> +			!S_ISREG(inode->i_mode))
> +		return -EINVAL;
> +
> +	if ((range.flags & F2FS_TRIM_FILE_DISCARD) &&
> +			!f2fs_hw_support_discard(sbi))
> +		return -EOPNOTSUPP;
> +
> +	file_start_write(filp);
> +	inode_lock(inode);
> +
> +	if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	if (inode->i_size == 0)
> +		goto err;
> +
> +	end_addr = range.start + range.len;
> +	if (end_addr > inode->i_size) {
> +		ret = -EINVAL;
> +		goto err;
> +	}

This is missing a check that range.start + range.len doesn't overflow.

- Eric