[LUCENE-2615] DirectIOLinuxDirectory hardwires buffer size and creates files with invalid permissions

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1, 4.0-ALPHA
• Component/s: modules/other
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Michael McCandless
• Created: 23/Aug/10 17:12
• Updated: 28/Aug/22 12:31
• Resolved: 23/Aug/10 17:26

Description

TestDemo fails if I use the DirectIOLinuxDirectory (using Robert's new -Dtests.directory=XXX), because when it O_CREATs a file, it fails to specify the mode, so [depending on C stack!] you can get permission denied.

Also, we currently hardwire the buffer size to 1 MB (Mark found this)... I plan to add a "forcedBufferSize" to the DirectIOLinuxDir's ctor, to optionally override lucene's default buffer sizes (which are way too small for direct IO to get barely OK performance). If you pass 0 for this then you get Lucene's default buffer sizes...