A new file server implementation using the SMB3 protocol has been proposed for inclusion in the next release of the Linux kernel. The server is designed as a ksmbd kernel module and complements the previously available SMB client code. It is noted that, unlike a user-space SMB server, a kernel-level implementation is more efficient in terms of performance, memory consumption, and integration with extended kernel capabilities.
From the capabilities of ksmbd stands out improved support for distributed file caching technology (SMB leases) on local systems, which can significantly reduce traffic. In the future, it is planned to add new features, such as support for RDMA ("smbdirect"), as well as protocol extensions related to increased encryption reliability and verification by digital signatures. It is noted that such extensions are much easier to implement in a compact and well-optimized server running at the kernel level than in the Samba package.
At the same time, ksmbd does not claim to be a complete replacement for the Samba package, which is not limited to the capabilities of a file server and provides a toolkit that covers security services, LDAP, and a domain controller. Samba's file server implementation is cross-platform and broader in scope, making it difficult to optimize for some Linux environments, such as firmware for resource-constrained devices.
Ksmbd is not seen as a standalone product, but rather as a high-performance, embedded-ready extension to Samba, integrating with Samba tools and libraries as needed. For example, the Samba developers have already agreed to use smbd-compatible configuration files and extended attributes (xattrs) in ksmbd, which will simplify the transition from smbd to ksmbd and vice versa.
The main authors of the ksmbd code are Namjae Jeon of Samsung and Hyunchul Lee of LG. ksmbd will be maintained in the kernel by Steve French of Microsoft (previously with IBM for many years), maintainer of the CIFS/SMB2/SMB3 subsystems in the Linux kernel and longtime member of the Samba development team, who has made significant contributions to the implementation of SMB protocol support. /CIFS on Samba and Linux.
Source: opennet.ru