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Bug ID: 4947349 REGRESSION: RH AS 3.0: prefs.removeNode throws BackingStoreException
4947349 : REGRESSION: RH AS 3.0: prefs.removeNode throws BackingStoreException

Details
Type:
Bug
Submit Date:
2003-10-31
Status:
Closed
Updated Date:
2004-03-31
Project Name:
JDK
Resolved Date:
2004-02-20
Component:
core-libs
OS:
solaris_8,linux_redhat_3.0,linux
Sub-Component:
java.util
CPU:
x86,sparc
Priority:
P2
Resolution:
Fixed
Affected Versions:
1.4.0,1.4.1,1.4.2,5.0
Fixed Versions:
5.0

Related Reports
Duplicate:
JDK-4673298 - (prefs) Locking in Preferences sometimes fails on NFS mounted drives (Linux)
Relates:
JDK-4762735 - (prefs) BackingStoreException thrown when preferences dir nfs share

Sub Tasks

Description
Build: Tiger beta b26
Platform: Redhat Advanced Server 3.0 (x86)

Tests:
java_util/prefs/Preferences/SJvm2Thread/userRoot/KeysTest2SJvm2Thread 
and 15 other related tests.

In Redhat Linux AS 3.0, java.util.prefs.BackingStoreException is thrown when Preferences.removeNode() is called. The following piece of code illustrates it.

----------------------------Test.java-----------------------------
import java.util.prefs.*;

public class Test 
{
	public static void main(String[] args)
	{
		Preferences userRoot = null;
		Preferences N1 = null;
		try 
		{
	        userRoot = Preferences.userRoot();
                N1 = userRoot.node("N1");
                N1.clear();
                N1.removeNode();
 
        } catch (Exception e) 
        {
          System.out.println("Exception caught:"+ e.getMessage());
      	}
    }
}

------------------------------------------------------------------------
the following is the output
------------------------------------------------------------------------
Oct 31, 2003 2:37:51 PM java.util.prefs.FileSystemPreferences checkLockFile0ErrorCode
WARNING: Could not lock User prefs. Unix error code 22.
Exception caught:Couldn't get file lock.
java.util.prefs.BackingStoreException: Couldn't get file lock.
	at java.util.prefs.FileSystemPreferences.removeNode(FileSystemPreferences.java:657)
	at Test.main(Test.java:29)
------------------------------------------------------------------------

The above code is run on the local system (not on a nfs file system). 

The above problem is not observed with mantis.
 
###@###.### 2003-10-31

Comments
CONVERTED DATA

BugTraq+ Release Management Values

COMMIT TO FIX:
tiger-beta2

FIXED IN:
tiger-beta2

INTEGRATED IN:
tiger-b40
tiger-beta2

VERIFIED IN:
tiger-beta2
2004-06-14 
PUBLIC COMMENTS

Verified by checking the testcase pass in tiger b41 on AS3.0, b43/b44 on AS3.0 AMD.
###@###.### 2004-03-30
2004-03-30 
SUGGESTED FIX

A previous fix which replaced file locking implementation (migrated from using lockf to
using fcntl(fd, F_SETLK64,..) also incorporated a preprocessor directive specific to
Linux J2SE compiled native code which was aimed at making file locking work for older
2.2.x based Linux distros. However, the validity of this preprocessor directive
(which used 'struct flock' in preference to 'struct flock64' for fcntl file locking
operation params and was fragile/sensitive to the Linux build environment (C headers/libs,etc))
does not hold across all Linux 2.4.x supported distros. Since 2.2.x distros are no 
longer officially supported for 1.5.0 an immediate effective fix is to remove the
preprocessor directive and
###@###.### 2004-02-10
2004-02-10 
EVALUATION

See Suggested fix. Linux native implementation for java.util.prefs includes native
file locking code used exclusively by java.util.prefs. As per previous comments this
should be removed and should be replaced by file locking code using the facilities
provided by the java.nio, java.nio.channels package. A more immediate effective fix
is to remove an unnecessary preprocessor directive in the Linux native file locking
impl which provides a fragile and incorrect typedef for the file locking params.
Should use struct flock64 and never use struct flock for file locking params.

java.nio implementation should be provided for 1.5.1
###@###.### 2004-02-10
2004-02-10


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