For inclusion in the next release of the Linux kernel, a new implementation of a file server using the SMB3 protocol has been proposed. The server is designed as a kernel module ksmbd and complements the previously available SMB client code. It is noted that unlike the SMB server, which operates in user space, the implementation at the kernel level is more efficient in terms of performance, memory consumption, and integration with the extended capabilities of the kernel.
Among the features of ksmbd is improved support for the technology of distributed file caching (SMB leases) on local systems, significantly reducing traffic. In the future, the addition of new capabilities is planned, such as support for RDMA ("smbdirect"), as well as protocol extensions related to enhancing encryption reliability and digital signature verification. It is noted that such extensions are much easier to implement in a compact and well-optimized serverenkernel-level environment than in the Samba package.
At the same time, ksmbd does not intend to fully replace the Samba package, which is not limited to file server capabilities server and provides tools encompassing security services, LDAP, and domain controller functionality. The file server implementation in Samba is cross-platform and designed for broader areas of application, making optimization for certain Linux environments, such as firmware for resource-constrained devices, more difficult.
Ksmbd is viewed not as a separate product, but rather as a high-performance and ready-to-use extension for embedded devices to Samba, which can be integrated with Samba tools and libraries if necessary. For example, the use of compatible configuration files and extended attributes (xattrs) in ksmbd has already been agreed upon with the Samba developers, simplifying the transition from smbd to ksmbd and vice versa.
The main authors of the ksmbd code are Namjae Jeon from Samsung and Hyunchul Lee from LG. The maintenance of ksmbd in the kernel will be handled by Steve French from Microsoft (who previously worked at IBM for many years), the maintainer of the CIFS/SMB2/SMB3 subsystem in the Linux kernel and a long-time participant in the Samba development team, who has made significant contributions to the implementation of SMB/CIFS protocol support in both Samba and Linux.
Kilde: opennet.ru
