[LU-19137] Support for kernel 6.15

• Type: Bug
• Resolution: Fixed
• Priority: Medium
• Fix Version/s: Lustre 2.17.0
• Severity: 3
• Assignee: Shaun Tancheff
• Reporter: Shaun Tancheff

Description

Update support for kernel 6.15:

• wait_on_page_locked() removed
  open code the folio compat wrapper until general folio support is landed.
• grab_cache_page_write_begin() removed
  open code the folio compat wrapper until general folio support is landed.

• hrtimer_init removed – use hrtimer_setup() and provide compat for older kernels

• sysctl_vfs_cache_pressure removed, use vfs_pressure_ratio() compat for el7?

• inode_operations->mkdir() should return a dentry() compat for older kernels.