HP CIFS File Locking Interoperation

B.3 Mandatory Share Mode (Open Mode) Locks

Previously, CIFS/9000 Mandatory Share Mode (Open Mode) locks were processed and

managed by the Samba Internal Locking Mechanism only. They were not translated into the

UNIX fcntl call and propagated to the Kernel Lock Manager. Therefore, Mandatory Share

Mode (Open Mode) locks did not interoperate with NFS Byte Range locks at the KLM, and

data corruption could result in those cases where concurrent file access by both CIFS and

NFS clients was probable

See Appendix B4 for HP’s enhancement for this issue.

CIFS/NFS Open Mode Locking

Old Behavior pre-Sept 2001

Samba

Samba Internal

Locking

Mechanism

NLM

Network Lock

Manager

KLM

Kernel Lock

Manager

User space

Kernel space Kernel space

User space

HP-UX 11

JFS 3.3 File System

CIFS NFS

Open Mode Lock Byte Range Lock

Open Mode Locks DO NOT

Interoperate at KLM!