[LU-353] write should return written bytes when it's interrupted

• Type: Bug
• Resolution: Unresolved
• Priority: Major
• Affects Version/s: Lustre 2.0.0, Lustre 2.1.0
• Severity: 3
• Assignee: WC Triage
• Reporter: Niu Yawei (Inactive)

Description

When I was investigating on LU-305, I found that ll_file_write() (master code) always return error to user application where error happened, even if there is data be written, which is not POSIX complied. We should return written bytes if there is any written data.