[LU-14073] Support for linux kernel version 5.9

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Assignee: Neil Brown
• Reporter: Neil Brown

Description

Now that Linux 5.9 is in released it makes sense to support compiling against it

This requires:

• ldiskfs patch updates to follow kernel extt4 changes.
• removal of smp_read_barrier_depends() which no longer exists
• Fix autoconf check for clean_bdev_aliases which no longer works
• Remove dependence on seqment_eq() which no longer exits.

Issue Links

• is related to: LU-12511 Prepare lustre for adoption into the linux kernel