Contact Us Contact Us

LOCKFCFS

  Software Depot
Electronic download
Frequently asked questions
Product details and specifications
Select
Overview

This product delivers a kernel module "lockf_cfs" to provide enhancements and fixes in the file segment lock functionality on HP-UX 11i v2.

 

What is new in the version 5.0?

 

This release of LockfCFS contains the defect fix for QXCR1001381032 and QXCR1001216622.

 

What is new in the version 4.0?

New feature

  • 64-bit file segment lock.  

LockfCFS provides the enhanced Virtual File System kernel module lockf_cfs to support the 64-bit file segment lock feature for lockf(2) and fcntl(2) system calls on HP-UX irrespective of the maximum file size supported by the physical file system.

 

When a file lock range with lock start or end greater than 2TB or maximum file size supported by underlying file system is requested through the fcntl(2) and lockf(2) system calls, the current HP-UX implementation fails with an Invalid argument(EINVAL) error.

 

For instance, consider a 64-bit application requesting a file lock through fcntl(2) that starts at 9223372036854775807 and the length of 0 on a file which resides on the HFS file system. Such a lock start and the end are beyond 2TB, system calls fcntl(2) or lockf(2) fail with the EINVAL error.

 

Delivery of the solution

The complete solution is delivered in three Enablement Patches (EPs) and one New Core Functionality (NCF) bundle form as described below.

 

  • NCF kernel module:

lockf_cfs:

This module delivers the changes in the fcntl(2), lockf(2), pstat_getfiledetails(2) system calls and the kernel interfaces in VFS layer that are required to provide the 64-bit file segment lock feature.

 

  • EP Patches:

PHKL_42673: s700_800 11.23 pstat panic

Delivers the changes required in pstat_getfiledetails(2) system call to enable the 64-bit file segment lock feature.

 

PHKL_42674: s700_800 11.23 FD management, voncelocked,dup2 race

Delivers the changes required in fcntl(2) and lockf(2) system call to enable the 64-bit file segment lock feature.

   

PHKL_42675: s700_800 11.23 Lockf Patch

Delivers the changes required in kernel interfaces in the VFS layer to enable the 64-bit file segment lock feature.

 

 

Notes:

  • For the solution to work as expected, all the 3 Enablement Patches must be installed.

The behaviour is not specified if any one of the patches is not installed.

  • The 64-bit file segment lock feature enhances the file segment lock to the 64-bit offsets only for fcntl(2) and lockf(2) system calls. This solution does not alter the maximum file size supported by the physical file system for other file system operations like read(2), write(2). Hence a read(2)or write(2) request on a file with an offset or size that is beyond the end of file or the maximum file size supported by the physical file system will still fail.

 

What is new in the version 3.0?

On an HP-UX 11i v2 system, while using lockf() over Cluster Filesystems (CFS), a deadlock may occur during the Global Lock Manager (GLM) revocation path. This issue does not occur on HP-UX 11i v3. The VFS local_lockctl() function is redesigned to avoid a deadlock while using lockf() over CFS. As a result, deadlock does not occur. Installing this bundle along with the dependent patches enables the usage of lockf() over CFS without causing the deadlock.

 

 

 
Additional product information
Product #: LOCKFCFS
Version: 5.0
Software specification: B.11.23.05(LOCKFCFS_bundlev5.depot)
Installation
Select