[HDFS-7263] Snapshot read can reveal future bytes for appended files.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.5.0
• Fix Version/s: 2.7.0, 2.6.1, 3.0.0-alpha1
• Component/s: hdfs-client
• Labels: 2.6.1-candidate
• Target Version/s: 2.7.0
• Assignee: Tao Luo
• Reporter: Konstantin Shvachko
• Created: 17/Oct/14 22:38
• Updated: 01/Sep/16 04:13
• Resolved: 30/Oct/14 03:25

Description

The following sequence of steps will produce extra bytes, that should not be visible, because they are not in the snapshot.

• Create a file of size L, where L % blockSize != 0.
• Create a snapshot
• Append bytes to the file
• Read file in the snapshot (not the current file)
• You will see the bytes are read beoynd the original file size L

Issue Links

• is related to: HDFS-10825 Snapshot read can reveal future bytes if snapshotted while writing
• is required by: HDFS-7056 Snapshot support for truncate
• relates to: HDFS-5343 When cat command is issued on snapshot files getting unexpected result