[LU-14651] Linux kernel 5.12 support

• Type: Improvement
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.15.0
• Affects Version/s: Lustre 2.15.0
• Environment: Any system running 5.12 kernel.
• Assignee: James A Simmons
• Reporter: James A Simmons

Description

The 5.12 Linux kernel has just been released. Moving the native Linux client to this version exposed various kernel API changes:

1) Support of IDMAPPED mounts. The impact on Lustre is struct user_namespace is passed to all VFS operations.  You can read about this feature at - https://lwn.net/Articles/842423

2) fscrypto API has been reworked.

3) Linux kernel will not build UAPI headers with our CONF_T_* values.

4) rdma_reject() returns an error string to print out.

5) setsockopt uses a new sockptr_t abstract to handle both userland and kernel space at the same tim.

Issue Links

• is related to: LU-15220 Linux kernel 5.14 support
• is related to: LU-12511 Prepare lustre for adoption into the linux kernel