[HDFS-14731] [FGL] Remove redundant locking on NameNode.

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.3.0, 3.1.4, 3.2.2
• Component/s: namenode
• Target Version/s: 3.3.0
• Hadoop Flags: Reviewed
• Assignee: Konstantin Shvachko
• Reporter: Konstantin Shvachko
• Created: 14/Aug/19 22:24
• Updated: 02/Oct/21 08:33
• Resolved: 28/Feb/20 00:13

Description

Currently NameNode has two global locks: FSNamesystemLock and FSDirectoryLock. An analysis shows that single FSNamesystemLock is sufficient to guarantee consistency of the NameNode state. FSDirectoryLock can be removed.

Issue Links

• is related to: HDFS-15076 Fix tests that hold FSDirectory lock, without holding FSNamesystem lock.