(fs) Extended attributes assumed to be enabled on ext3 (lnx)

After JDK-8009632, we see errors in the jtreg test

java/nio/file/attribute/DosFileAttributeView/Basic.java

failing with :

java.nio.file.FileSystemException: /priv/jvmtests/output_11_o_jdk-test_optU_linuxs390x/jtreg_jdk_java_work/tmp/name6376906360197868835/foo: Operation not supported
at java.base/sun.nio.fs.UnixException.translateToIOException(UnixException.java:100)
at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
at java.base/sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:116)
at java.base/sun.nio.fs.LinuxDosFileAttributeView.updateDosAttribute(LinuxDosFileAttributeView.java:278)
at java.base/sun.nio.fs.LinuxDosFileAttributeView.setReadOnly(LinuxDosFileAttributeView.java:191)
at Basic.testAttributes(Basic.java:45)
at Basic.readWriteTests(Basic.java:79)
at Basic.main(Basic.java:148)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:832)

Before 8009632 we returned false in LinuxFileStore.java supportsFileAttributeView for DosFileAttributeView for ext3 / ext4 .
Now we return true for ext3/ext4 in the case that nouser_xattr is not set .
So it is assumed that the default is always “extended attrs enabled” .
But this is not true on our SLES11 test machine with ext3 file system ; the machine has kernel 3.0.101-63-default .

For ext4, there is some info that user_xattr has been enabled by default for ext4 in kernel 2.6.39 .
Not sure about ext3 , we might probe the file system there , or check the Linux kernel version.