HP UX Common Internet File System (CIFS) Client/Server Software manual CIFS/NFS Open Mode Locking

B.3	Mandatory Share Mode (Open Mode) Locks
	CIFS/NFS Open Mode Locking
CIFS	Old Behavior pre-Sept 2001 NFS

Open Mode Lock

HP-UX 11

Byte Range Lock

Samba	Samba Internal	NLM
	Locking	Network Lock
	Mechanism
		Manager
User space		User space
Kernel space		Kernel space
		KLM
		Kernel Lock
		Manager

Open Mode Locks DO NOT	JFS 3.3 File System
Interoperate at KLM!

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.

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