[HDFS-7997] The first non-existing xattr should also throw IOException

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.6.0
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Target Version/s: 2.8.0
• Hadoop Flags: Reviewed
• Assignee: zhouyingchao
• Reporter: zhouyingchao
• Created: 27/Mar/15 07:37
• Updated: 30/Aug/16 01:37
• Resolved: 31/Mar/15 13:22

Description

We use the following code snippet to get/set xattrs. However, if there are no xattrs have ever been set, the first getXAttr returns null and the second one just throws exception with message like "At least one of the attributes provided was not found.". This is not expected, we believe they should behave in the same way - i.e either both getXAttr returns null or both getXAttr throw exception with the message "... not found". We will provide a patch to make them both throw exception.

....
attrValueNM = fs.getXAttr(path, "nm");
if (attrValueNM == null) {
fs.setXAttr("nm", DEFAULT_VALUE);
}
attrValueNN = fs.getXAttr(path, "nn");
if (attrValueNN == null) {
fs.setXAttr("nn", DEFAULT_VALUE);
}
....