[HDFS-7495] Remove updatePosition argument from DFSInputStream#getBlockAt()

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.7.0
• Fix Version/s: 2.7.0
• Target Version/s: 2.7.0
• Assignee: Colin McCabe
• Reporter: Ted Yu
• Created: 08/Dec/14 22:30
• Updated: 10/Apr/15 20:29
• Resolved: 25/Feb/15 21:39

Description

There're two locks: one on DFSInputStream.this , one on DFSInputStream.infoLock
Normally lock is obtained on infoLock, then on DFSInputStream.infoLock

However, such order is not observed in DFSInputStream#getBlockAt() :

    synchronized(infoLock) {
...
      if (updatePosition) {
        // synchronized not strictly needed, since we only get here
        // from synchronized caller methods
        synchronized(this) {

Issue Links

• is related to: HDFS-6735 A minor optimization to avoid pread() be blocked by read() inside the same DFSInputStream