ovl: add reflink/copyfile/dedup support (8ede2055) · Commits · EulixOS / Software / Kernel

fs/overlayfs/file.c

+87 −0

Original line number	Diff line number	Diff line
		@@ -389,6 +389,89 @@ static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
		return ovl_ioctl(file, cmd, arg);
		}

		enum ovl_copyop {
		OVL_COPY,
		OVL_CLONE,
		OVL_DEDUPE,
		};

		static ssize_t ovl_copyfile(struct file *file_in, loff_t pos_in,
		struct file *file_out, loff_t pos_out,
		u64 len, unsigned int flags, enum ovl_copyop op)
		{
		struct inode *inode_out = file_inode(file_out);
		struct fd real_in, real_out;
		const struct cred *old_cred;
		ssize_t ret;

		ret = ovl_real_fdget(file_out, &real_out);
		if (ret)
		return ret;

		ret = ovl_real_fdget(file_in, &real_in);
		if (ret) {
		fdput(real_out);
		return ret;
		}

		old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
		switch (op) {
		case OVL_COPY:
		ret = vfs_copy_file_range(real_in.file, pos_in,
		real_out.file, pos_out, len, flags);
		break;

		case OVL_CLONE:
		ret = vfs_clone_file_range(real_in.file, pos_in,
		real_out.file, pos_out, len);
		break;

		case OVL_DEDUPE:
		ret = vfs_dedupe_file_range_one(real_in.file, pos_in,
		real_out.file, pos_out, len);
		break;
		}
		revert_creds(old_cred);

		/* Update size */
		ovl_copyattr(ovl_inode_real(inode_out), inode_out);

		fdput(real_in);
		fdput(real_out);

		return ret;
		}

		static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
		struct file *file_out, loff_t pos_out,
		size_t len, unsigned int flags)
		{
		return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
		OVL_COPY);
		}

		static int ovl_clone_file_range(struct file *file_in, loff_t pos_in,
		struct file *file_out, loff_t pos_out, u64 len)
		{
		return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0,
		OVL_CLONE);
		}

		static int ovl_dedupe_file_range(struct file *file_in, loff_t pos_in,
		struct file *file_out, loff_t pos_out, u64 len)
		{
		/*
		* Don't copy up because of a dedupe request, this wouldn't make sense
		* most of the time (data would be duplicated instead of deduplicated).
		*/
		if (!ovl_inode_upper(file_inode(file_in)) \|\|
		!ovl_inode_upper(file_inode(file_out)))
		return -EPERM;

		return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0,
		OVL_DEDUPE);
		}

		const struct file_operations ovl_file_operations = {
		.open = ovl_open,
		.release = ovl_release,
		@@ -400,4 +483,8 @@ const struct file_operations ovl_file_operations = {
		.fallocate = ovl_fallocate,
		.unlocked_ioctl = ovl_ioctl,
		.compat_ioctl = ovl_compat_ioctl,

		.copy_file_range = ovl_copy_file_range,
		.clone_file_range = ovl_clone_file_range,
		.dedupe_file_range = ovl_dedupe_file_range,
		};