[LU-16667] Linux 6.3 client support

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Assignee: Shaun Tancheff
• Reporter: Shaun Tancheff

Description

New struct mnt_idmap wraps user namespace struct and changes several inode_operations functions (getattr, setattr ...)

New header <linux/filelock.h> and also breaks locks_lock_file_wait() test.

struct kernel_cap_t changed from any array of u32s to a single u64 breaking several lustre apis.

Continue using the lower 32 bits to maintain compatibility:

As of linux commit v3.6-10973-g607ca46e97a1 lustre implicitly
started to ignore some capabilities, see: include/uapi/linux/capability.h
Last capability flag was added in linux commit v5.8-rc5-1-g124ea650d307
The capabilities the Lustre ignores are:

• CAP_MAC_OVERRIDE
• CAP_MAC_ADMIN
• CAP_SYSLOG
• CAP_WAKE_ALARM
• CAP_BLOCK_SUSPEND
• CAP_AUDIT_READ
• CAP_PERFMON
• CAP_BPF
• CAP_CHECKPOINT_RESTORE
  None of which appear to be important to Lustre operations and should
  be fine to continue ignore.