[LU-8656] IS_NOSEC check in vvp_io_write_start always returns false

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.10.0
• Severity: 3
• Assignee: Patrick Farrell
• Reporter: Patrick Farrell

Description

In vvp_io_write_start, we check "IS_NOSEC" to see whether or not to take the inode mutex. (This is to protect the automatic setuid bit removal when writing to a file.)

This was added in patch http://review.whamcloud.com/19840 "LU-8025 llite: make vvp_io_write_start lockless for newer kernels".

Unfortunately, it looks like that check is not working correctly, and is always returning false, causing us to take the inode mutex. This may have some dependence on kernel version, as different versions vary in whether they provide IS_NOSEC.

Issue Links

• is related to: LU-8025 ll_direct_io code introduced in LU-6260 is based on 2.4/2.5, ignores LU-1669
• is related to: LU-8162 Get i_mutex lock when changing SUID bits